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Stampfer O, Zuidema C, Allen RW, Fox J, Sampson P, Seto E, Karr CJ. Practical considerations for using low-cost sensors to assess wildfire smoke exposure in school and childcare settings. J Expo Sci Environ Epidemiol 2024:10.1038/s41370-024-00677-8. [PMID: 38730039 DOI: 10.1038/s41370-024-00677-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 04/15/2024] [Accepted: 04/15/2024] [Indexed: 05/12/2024]
Abstract
BACKGROUND More frequent and intense wildfires will increase concentrations of smoke in schools and childcare settings. Low-cost sensors can assess fine particulate matter (PM2.5) concentrations with high spatial and temporal resolution. OBJECTIVE We sought to optimize the use of sensors for decision-making in schools and childcare settings during wildfire smoke to reduce children's exposure to PM2.5. METHODS We measured PM2.5 concentrations indoors and outdoors at four schools in Washington State during wildfire smoke in 2020-2021 using low-cost sensors and gravimetric samplers. We randomly sampled 5-min segments of low-cost sensor data to create simulations of brief portable handheld measurements. RESULTS During wildfire smoke episodes (lasting 4-19 days), median hourly PM2.5 concentrations at different locations inside a single facility varied by up to 49.6 µg/m3 (maximum difference) during school hours. Median hourly indoor/outdoor ratios across schools ranged from 0.22 to 0.91. Within-school differences in concentrations indicated that it is important to collect measurements throughout a facility. Simulation results suggested that making handheld measurements more often and over multiple days better approximates indoor/outdoor ratios for wildfire smoke. During a period of unstable air quality, PM2.5 over the next hour indoors was more highly correlated with the last 10-min of data (mean R2 = 0.94) compared with the last 3-h (mean R2 = 0.60), indicating that higher temporal resolution data is most informative for decisions about near-term activities indoors. IMPACT STATEMENT As wildfires continue to increase in frequency and severity, staff at schools and childcare facilities are increasingly faced with decisions around youth activities, building use, and air filtration needs during wildfire smoke episodes. Staff are increasingly using low-cost sensors for localized outdoor and indoor PM2.5 measurements, but guidance in using and interpreting low-cost sensor data is lacking. This paper provides relevant information applicable for guidance in using low-cost sensors for wildfire smoke response.
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Affiliation(s)
- Orly Stampfer
- University of Washington Department of Environmental and Occupational Health Sciences, 4225 Roosevelt Way NE, Seattle, WA, 98105, USA.
| | - Christopher Zuidema
- University of Washington Department of Environmental and Occupational Health Sciences, 4225 Roosevelt Way NE, Seattle, WA, 98105, USA
| | - Ryan W Allen
- Simon Fraser University Faculty of Health Sciences, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Julie Fox
- Washington State Department of Health, 101 Israel Rd. S.E., Tumwater, WA, 98501, USA
| | - Paul Sampson
- University of Washington Department of Statistics; B-313 Padelford Hall, Seattle, WA, 98195, USA
| | - Edmund Seto
- University of Washington Department of Environmental and Occupational Health Sciences, 4225 Roosevelt Way NE, Seattle, WA, 98105, USA
| | - Catherine J Karr
- University of Washington Department of Environmental and Occupational Health Sciences, 4225 Roosevelt Way NE, Seattle, WA, 98105, USA
- University of Washington Department of Pediatrics, 4245 Roosevelt Way NE, Seattle, WA, 98105, USA
- Northwest Pediatric Environmental Health Specialty Unit, 4225 Roosevelt Way NE, Seattle, WA, 98105, USA
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Bekbulat B, Agrawal P, Allen RW, Baum M, Boldbaatar B, Clark LP, Galsuren J, Hystad P, L’Orange C, Vakacherla S, Volckens J, Marshall JD. Application of an Ultra-Low-Cost Passive Sampler for Light-Absorbing Carbon in Mongolia. Sensors (Basel) 2023; 23:8977. [PMID: 37960676 PMCID: PMC10647794 DOI: 10.3390/s23218977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/29/2023] [Accepted: 11/02/2023] [Indexed: 11/15/2023]
Abstract
Low-cost, long-term measures of air pollution concentrations are often needed for epidemiological studies and policy analyses of household air pollution. The Washington passive sampler (WPS), an ultra-low-cost method for measuring the long-term average levels of light-absorbing carbon (LAC) air pollution, uses digital images to measure the changes in the reflectance of a passively exposed paper filter. A prior publication on WPS reported high precision and reproducibility. Here, we deployed three methods to each of 10 households in Ulaanbaatar, Mongolia: one PurpleAir for PM2.5; two ultrasonic personal aerosol samplers (UPAS) with quartz filters for the thermal-optical analysis of elemental carbon (EC); and two WPS for LAC. We compared multiple rounds of 4-week-average measurements. The analyses calibrating the LAC to the elemental carbon measurement suggest that 1 µg of EC/m3 corresponds to 62 PI/month (R2 = 0.83). The EC-LAC calibration curve indicates an accuracy (root-mean-square error) of 3.1 µg of EC/m3, or ~21% of the average elemental carbon concentration. The RMSE values observed here for the WPS are comparable to the reported accuracy levels for other methods, including reference methods. Based on the precision and accuracy results shown here, as well as the increased simplicity of deployment, the WPS may merit further consideration for studying air quality in homes that use solid fuels.
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Affiliation(s)
- Bujin Bekbulat
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA 98195, USA; (B.B.); (L.P.C.)
| | - Pratyush Agrawal
- Center for Study of Science, Technology & Policy, Bengaluru 560095, Karnataka, India; (P.A.); (S.V.)
| | - Ryan W. Allen
- Department of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada;
| | | | - Buyantushig Boldbaatar
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar 14210, Mongolia; (B.B.); (J.G.)
| | - Lara P. Clark
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA 98195, USA; (B.B.); (L.P.C.)
| | - Jargalsaikhan Galsuren
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar 14210, Mongolia; (B.B.); (J.G.)
| | - Perry Hystad
- Department of Public Health and Human Sciences, Oregon State University, Corvallis, OR 97331, USA;
| | - Christian L’Orange
- Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523, USA; (C.L.); (J.V.)
| | - Sreekanth Vakacherla
- Center for Study of Science, Technology & Policy, Bengaluru 560095, Karnataka, India; (P.A.); (S.V.)
| | - John Volckens
- Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523, USA; (C.L.); (J.V.)
| | - Julian D. Marshall
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA 98195, USA; (B.B.); (L.P.C.)
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Faridi S, Allen RW, Brook RD, Yousefian F, Hassanvand MS, Carlsten C. An updated systematic review and meta-analysis on portable air cleaners and blood pressure: Recommendations for users and manufacturers. Ecotoxicol Environ Saf 2023; 263:115227. [PMID: 37421892 DOI: 10.1016/j.ecoenv.2023.115227] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/29/2023] [Accepted: 07/01/2023] [Indexed: 07/10/2023]
Abstract
Fine particulate matter (PM2.5) air pollution is a leading contributor to the global burden of cardiovascular disease (CVD). One important underlying mechanism is an increase in blood pressure (BP). A growing number of studies have reported a beneficial effect of portable air cleaners (PACs) on systolic and diastolic BP; SBP and DBP. We conducted an updated systematic review and meta-analysis of studies using true versus sham mode filtration reporting the effects on BP. Of 214 articles identified up to February 5, 2023, seventeen (from China, USA, Canada, South Korea and Denmark) enrolling approximately 880 participants (484 female) met the inclusion criteria for meta-analyses. Aside from studies conducted in China, research on PACs and BP has been conducted in relatively low pollution settings. Mean indoor PM2.5 concentrations during the active and sham mode purification were 15.9 and 41.2 µg/m3, respectively. The mean efficiency of PACs against indoor PM2.5 was 59.8 % (ranging from 23 % to 82 %). True mode filtration was associated with a pooled mean difference of - 2.35 mmHg (95 % confidence interval [CI]: - 4.5, - 0.2) and - 0.81 mmHg (95 % CI: - 1.86, 0.24) in SBP and DBP, respectively. After removing the studies with high risk of bias, the magnitude of the pooled benefits on SBP and DBP increased to - 3.62 mmHg (95 % CI: - 6.69, - 0.56) and - 1.35 mmHg (95 % CI: - 2.29, - 0.41), respectively. However, there are several barriers to the use of PACs, specifically in low- and middle-income countries (LMICs), such as the initial purchase cost and filter replacements. There may be several avenues to help overcome these economic burdens and improve cost effectiveness, such as implementing government or other subsidized programs to distribute PACs targeting vulnerable and higher-risk individuals. We propose that environmental health researchers and healthcare providers should be better trained to educate the public regarding the use of PACs to reduce the impacts of PM2.5 on cardiometabolic diseases globally.
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Affiliation(s)
- Sasan Faridi
- Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran; Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran.
| | - Ryan W Allen
- Simon Fraser University, Burnaby, British Columbia, Canada
| | | | - Fatemeh Yousefian
- Department of Environmental Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Islamic Republic of Iran
| | - Mohammad Sadegh Hassanvand
- Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran; Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran
| | - Christopher Carlsten
- Air Pollution Exposure Lab and Legacy for Airway Health, Vancouver Coastal Health Research Institute and University of British Columbia, Vancouver, Canada.
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Ulziikhuu B, Gombojav E, Banzrai C, Batsukh S, Enkhtuya E, Boldbaatar B, Bellinger DC, Lanphear BP, McCandless LC, Nepomnaschy P, Salvante K, Weinberg J, Allen RW. Who benefits most from a prenatal HEPA filter air cleaner intervention on childhood cognitive development? The UGAAR randomized controlled trial. Environ Res 2023; 231:115991. [PMID: 37121346 DOI: 10.1016/j.envres.2023.115991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 04/05/2023] [Accepted: 04/24/2023] [Indexed: 05/10/2023]
Abstract
BACKGROUND Air pollution exposure during pregnancy affects children's brain function. Maternal stress and nutrition, socioeconomic status, and the child's sex may modify this relationship. OBJECTIVE To identify characteristics of children with the largest increases in full-scale IQ (FSIQ) after their mothers used HEPA filter air cleaners during pregnancy. METHODS In this randomized controlled trial we randomly assigned women to receive 1-2 air cleaners or no air cleaners during pregnancy. We analyzed maternal hair samples for cortisol and dehydroepiandrosterone (DHEA). When the children were 48 months old, we measured FSIQ with the Wechsler Preschool and Primary Scale of Intelligence. We evaluated ten potential modifiers of the intervention-FSIQ relationship using interaction terms in separate regression models. To account for correlations between modifiers, we also used a single regression model containing main effects and intervention x modifier terms for all potential modifiers. RESULTS Among 242 mother-child dyads with complete data, the intervention was associated with a 2.3-point increase (95% CI: -1.5, 6.0 points) in mean FSIQ. The intervention improved mean FSIQ among children of mothers in the bottom (5.4 points; 95% CI: -0.8, 11.5) and top (6.1 points; 95% CI: 0.5, 11.8) cortisol tertiles, but not among those whose mothers were in the middle tertile. The largest between-group difference in the intervention's effect was a 7.5-point (95% CI: -0.7, 15.7) larger increase in mean FSIQ among children whose mothers did not take vitamins than among children whose mothers did take vitamins (interaction p-value = 0.07). We also observed larger benefits among children whose mothers did not complete university, and those with lower hair DHEA concentrations, hair cortisol concentrations outside the middle tertile, or more perceived stress. CONCLUSION The benefits of reducing air pollution during pregnancy on brain development may be greatest for children whose mothers who do not take vitamins, experience more stress, or have less education.
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Affiliation(s)
| | | | | | - Sarangerel Batsukh
- Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Enkhtuul Enkhtuya
- Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | | | | | | | | | | | | | - Joanne Weinberg
- University of British Columbia, Faculty of Medicine, Vancouver, BC, Canada
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5
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Enkhbat U, Gombojav E, Banzrai C, Batsukh S, Boldbaatar B, Enkhtuya E, Bellinger DC, Lanphear BP, McCandless LC, Allen RW. Portable HEPA filter air cleaner use during pregnancy and children's autistic behaviors at four years of age: The UGAAR randomized controlled trial. Environ Int 2022; 168:107432. [PMID: 36007302 DOI: 10.1016/j.envint.2022.107432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 06/22/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Developmental exposure to airborne particulate matter (PM) may increase children's risk of developing autism spectrum disorder. We quantified the impact of reducing PM exposure during pregnancy on the development of autistic traits in children. We also assessed associations between indoor fine PM (PM2.5) concentrations during pregnancy and autistic traits. METHODS In this parallel-group randomized controlled trial, we randomized 540 non-smoking pregnant women to receive HEPA filter air cleaners or to a control group, which did not receive air cleaners. We administered the Social Responsiveness Scale (SRS-2) to caregivers when children were a median of 48 months (range: 48 to 51 months). Our primary outcome was the SRS-2 total T-score. We imputed missing data using multiple imputation with chained equations and our primary analysis was by intention to treat. In secondary analyses, we estimated associations between full pregnancy and trimester-specific indoor PM2.5 concentrations and T-scores. RESULTS We enrolled participants at a median of 11 weeks' gestation. Our analysis included 478 children (233 control, 245 intervention). The intervention reduced average indoor PM2.5 concentrations by 29 % (95 % CI: 21, 37 %). The mean SRS-2 total T-score was 0.5 units lower (95 % CI: -2.5, 1.5) among intervention participants, with evidence of larger benefits for children at the high end of the T-score distribution. An interquartile range (9.6 µg/m3) increase in indoor PM2.5 during pregnancy was associated with 1.8-unit (95 % CI: 0.3, 3.2) increase in mean SRS-2 total T-score. Effect estimates for PM2.5 concentrations by trimester were smaller and confidence intervals spanned no effect. CONCLUSION Reducing indoor PM during pregnancy had little impact on mean autism-related behavior scores in children. However, indoor PM2.5 concentrations during pregnancy were associated with higher scores. Exposure to particulate matter during pregnancy may influence the development of autistic traits in childhood. TRIAL REGISTRATION ClinicalTrials.gov: NCT01741051.
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Affiliation(s)
- Undarmaa Enkhbat
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada; School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia.
| | - Enkhjargal Gombojav
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia.
| | - Chimeglkham Banzrai
- Institute of Medical Sciences, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia.
| | - Sarangerel Batsukh
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Buyantushig Boldbaatar
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia.
| | - Enkhtuul Enkhtuya
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - David C Bellinger
- Harvard Medical School, Boston Children's Hospital, Boston, MA, USA.
| | - Bruce P Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada.
| | | | - Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada.
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Shellington EM, Nguyen PDM, Rideout K, Barn P, Lewis A, Baillie M, Lutz S, Allen RW, Yao J, Carlsten C, Henderson SB. Public Health Messaging for Wildfire Smoke: Cast a Wide Net. Front Public Health 2022; 10:773428. [PMID: 35646797 PMCID: PMC9132092 DOI: 10.3389/fpubh.2022.773428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 03/24/2022] [Indexed: 12/04/2022] Open
Abstract
Wildfire smoke events are increasing in British Columbia (BC), Canada and environmental and public health agencies are responsible for communicating the health-related risks and mitigation strategies. To evaluate and identify opportunities for improving public communications about wildfire smoke and associated health risks we collaborated with end-users and developed a 32-question online survey. The survey was deployed province-wide from 29 September to 31 December 2020 following a severe wildfire smoke episode, which impacted large parts of BC. Using a convenience sample, we disseminated the survey through email lists, radio advertisements, a provincial research platform, and snowball methods. There were 757 respondents, who were generally representative of provincial demographics. Respondents indicated that they receive wildfire smoke messages from diverse sources, including: websites, social media, radio, and television. Radio was identified as the most important source of information for populations that may have increased exposure or health risks, including Indigenous respondents and those working in the trades. Respondents with lower educational attainment expressed that messaging should be simplified. Environmental and public health agencies should continue to share wildfire smoke messages using diverse methods, ideally tailoring the messages and methods to specific populations at risk for exposure and health effects.
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Affiliation(s)
- Erin M Shellington
- Legacy for Airway Health, Vancouver Coastal Health Research Institute, Vancouver, BC, Canada
| | - Phuong D M Nguyen
- Environmental Health Services, British Columbia Centre for Disease Control, Vancouver, BC, Canada
| | - Karen Rideout
- Legacy for Airway Health, Vancouver Coastal Health Research Institute, Vancouver, BC, Canada
| | - Prabjit Barn
- Legacy for Airway Health, Vancouver Coastal Health Research Institute, Vancouver, BC, Canada
| | - Anna Lewis
- Port Alberni Air Quality Council, Port Alberni, BC, Canada
| | - Margaret Baillie
- Community Stakeholder Committee, Legacy for Airway Health, Vancouver Coastal Health Research Institute, Vancouver, BC, Canada
| | - Sue Lutz
- Community Stakeholder Committee, Legacy for Airway Health, Vancouver Coastal Health Research Institute, Vancouver, BC, Canada
| | - Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Jiayun Yao
- British Columbia Observatory for Population and Public Health, British Columbia Centre for Disease Control, Vancouver, BC, Canada
| | - Christopher Carlsten
- Legacy for Airway Health, Vancouver Coastal Health Research Institute, Vancouver, BC, Canada.,Division of Respiratory Medicine, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,Faculty of Medicine, School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada
| | - Sarah B Henderson
- Environmental Health Services, British Columbia Centre for Disease Control, Vancouver, BC, Canada.,Faculty of Medicine, School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada
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Ulziikhuu B, Gombojav E, Banzrai C, Batsukh S, Enkhtuya E, Boldbaatar B, Bellinger DC, Lanphear BP, McCandless LC, Tamana SK, Allen RW. Portable HEPA Filter Air Cleaner Use during Pregnancy and Children's Cognitive Performance at Four Years of Age: The UGAAR Randomized Controlled Trial. Environ Health Perspect 2022; 130:67006. [PMID: 35730943 PMCID: PMC9221428 DOI: 10.1289/ehp10302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
BACKGROUND Developmental exposure to air pollution is associated with diminished cognitive abilities in observational studies, but no randomized controlled trial has examined the effect of reducing air pollution on cognition in children. OBJECTIVES We sought to quantify the impact of reducing exposure to particulate matter (PM) during pregnancy on children's cognitive performance at 4 y of age. METHODS In this single-blind, parallel-group, randomized controlled trial in Ulaanbaatar, Mongolia, we randomly assigned 540 nonsmoking pregnant women (268 intervention and 272 control) to receive 1-2 portable high-efficiency particulate air (HEPA) filter air cleaners or no air cleaners. The air cleaners were used from a median of 11 wk gestation until the end of pregnancy. The primary outcome was full-scale intelligence quotient (FSIQ) assessed using the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV) when children were a median of 48 months old. We imputed missing outcome data using multiple imputation with chained equations, and our primary analysis was by intention to treat. RESULTS After excluding known miscarriages, stillbirths, neonatal deaths, and medical conditions that impeded cognitive testing and imputation, 475 (233 control and 242 intervention) children were included in our analyses. In an unadjusted analysis, the mean FSIQ of children who were randomly assigned to the intervention group was 2.5 points [95% confidence interval (CI): -0.4, 5.4 points] higher than that of children in the control group. After adjustment to account for an imbalance in preterm birth between groups, the effect estimate increased to 2.8 points (95% CI: -0.1, 5.7). CONCLUSIONS Reducing PM air pollution during pregnancy may improve cognitive performance in childhood. https://doi.org/10.1289/EHP10302.
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Affiliation(s)
| | | | | | - Sarangerel Batsukh
- Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Enkhtuul Enkhtuya
- Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | | | | | | | | | | | - Ryan W. Allen
- Simon Fraser University, Burnaby, British Columbia, Canada
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Tamana SK, Gombojav E, Kanlic A, Banzrai C, Batsukh S, Enkhtuya E, Boldbaatar B, Lanphear BP, Lear SA, McCandless LC, Venners SA, Allen RW. Portable HEPA filter air cleaner use during pregnancy and children's body mass index at two years of age: The UGAAR randomized controlled trial. Environ Int 2021; 156:106728. [PMID: 34218184 DOI: 10.1016/j.envint.2021.106728] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/10/2021] [Accepted: 06/17/2021] [Indexed: 06/13/2023]
Abstract
IMPORTANCE Gestational exposure to particulate matter (PM) air pollution may increase the risk of childhood obesity, but the impact of reducing air pollution during pregnancy on obesity-related outcomes in childhood has not been examined. OBJECTIVE To assess the impact of reducing gestational PM exposure on body mass index (BMI) at two years of age. METHODS In this single-blind, parallel group randomized controlled trial in Ulaanbaatar Mongolia, we randomly assigned 540 pregnant women to receive 1-2 portable high efficiency particulate air (HEPA) filter air cleaners or no air cleaners. We measured height and weight when children were a mean age of 23.8 months. Our primary outcome was age- and sex-specific BMI z-score based on the World Health Organization 2007 Growth Charts. Secondary outcomes included age- and sex-specific weight z score, overweight/obesity (defined as BMI z-score > 2.00), and catch-up growth (defined using various cut-offs to identify children with relatively low birth weight for sex and gestational age and relatively high age- and sex-specific weight in childhood). We imputed missing outcome data using multiple imputation with chained equations and our primary analysis was by intention to treat (ITT). We estimated intervention effects on continuous and binary outcomes using linear and logistic regression, respectively. RESULTS After excluding known miscarriages, still births, and neonatal deaths our analysis included 480 children (235 control and 245 intervention). The mean (SD) child BMI z score was 0.79 (1.0); 9.8% of children were overweight or obese. The mean BMI z score of children who were randomly assigned to the intervention group was 0.16-units lower (95% CI: -0.35, 0.04) than children in the control group. The intervention was also associated with reductions in overweight/obesity (odds ratio = 0.59; 95% CI: 0.31, 1.12). Catch-up growth occurred less frequently in the intervention group, but effect estimates varied depending on the specific definition of catch-up growth and confidence intervals consistently spanned no effect. CONCLUSIONS We found that the use of portable air cleaners during pregnancy was associated with improvements in obesity-related outcomes, although some effect estimates lacked precision. Reducing PM exposure during pregnancy may lead to improvements in cardiometabolic health in childhood.
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Affiliation(s)
- Sukhpreet K Tamana
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Enkhjargal Gombojav
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Adriana Kanlic
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Chimeglkham Banzrai
- Institute of Medical Sciences, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Sarangerel Batsukh
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Enkhtuul Enkhtuya
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Buyantushig Boldbaatar
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Bruce P Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Scott A Lear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | | | - Scott A Venners
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada.
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9
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Enkhbat U, Gombojav E, Banzrai C, Batsukh S, Boldbaatar B, Enkhtuya E, Ochir C, Bellinger DC, Lanphear BP, McCandless LC, Allen RW. Portable HEPA filter air cleaner use during pregnancy and children's behavior problem scores: a secondary analysis of the UGAAR randomized controlled trial. Environ Health 2021; 20:78. [PMID: 34225757 PMCID: PMC8258951 DOI: 10.1186/s12940-021-00763-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Developmental exposure to particulate matter (PM) air pollution may impair children's behaviors. Our objectives were to quantify the impact of reducing indoor PM using portable HEPA filter air cleaners during pregnancy on behavioral problems in children and to assess associations between indoor fine PM (PM2.5) concentrations during pregnancy and children's behavior. METHODS This is a secondary analysis of a single-blind parallel-group randomized controlled trial in which we randomly assigned 540 non-smoking pregnant women to receive 1 or 2 HEPA filter air cleaners or no air cleaners. We administered the Behavior Assessment System for Children (BASC-3) to caregivers when children were a mean age of 23 months, and again at a mean age of 48 months. Primary outcomes were the four BASC-3 composite scales: externalizing problems, internalizing problems, adaptive skills, and the behavioral symptoms index. We imputed missing data using multiple imputation with chained equations. The primary analysis was by intention-to-treat. In a secondary analysis, we evaluated associations between BASC-3 composite indices and modeled trimester-specific PM2.5 concentrations inside residences. RESULTS We enrolled participants at a median of 11 weeks gestation. After excluding miscarriages, still births and neonatal deaths, our analysis included 478 children (233 control and 245 intervention). We observed no differences in the mean BASC-3 scores between treatment groups. An interquartile increase (20.1 µg/m3) in first trimester PM2.5 concentration was associated with higher externalizing problem scores (2.4 units, 95% CI: 0.7, 4.1), higher internalizing problem scores (2.4 units, 95% CI: 0.7, 4.0), lower adaptive skills scores (-1.5 units, 95% CI: -3.0, 0.0), and higher behavior symptoms index scores (2.3 units, 95% CI: 0.7, 3.9). Third trimester PM2.5 concentrations were also associated with some behavioral indices at age 4, but effect estimates were smaller. No significant associations were observed with PM2.5 concentrations during the second trimester or for any of the BASC indices when children were 2 years old. CONCLUSION We found no benefit of reducing indoor particulate air pollution during pregnancy on parent-reported behaviors in children. Associations between indoor PM2.5 concentrations in the first trimester and behavioral scores among 4-year old children suggest that it may be necessary to intervene early in pregnancy to protect children, but these exploratory findings should be interpreted cautiously. TRIAL REGISTRATION ClinicalTrials.gov: NCT01741051.
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Affiliation(s)
- Undarmaa Enkhbat
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC Canada
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Enkhjargal Gombojav
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Chimeglkham Banzrai
- Institute of Medical Sciences, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Sarangerel Batsukh
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Buyantushig Boldbaatar
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Enkhtuul Enkhtuya
- School of Public Health, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Chimedsuren Ochir
- School of Graduate Studies, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | | | - Bruce P. Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC Canada
| | | | - Ryan W. Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC Canada
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Allen RW, Barn P. Individual- and Household-Level Interventions to Reduce Air Pollution Exposures and Health Risks: a Review of the Recent Literature. Curr Environ Health Rep 2020; 7:424-440. [PMID: 33241434 PMCID: PMC7749091 DOI: 10.1007/s40572-020-00296-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2020] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW We reviewed recent peer-reviewed literature on three categories of individual- and household-level interventions against air pollution: air purifiers, facemasks, and behavior change. RECENT FINDINGS High-efficiency particulate air/arresting (HEPA) filter air purifier use over days to weeks can substantially reduce fine particulate matter (PM2.5) concentrations indoors and improve subclinical cardiopulmonary health. Modeling studies suggest that the population-level benefits of HEPA filter air purification would often exceed costs. Well-fitting N95 and equivalent respirators can reduce PM2.5 exposure, with several randomized crossover studies also reporting improvements in subclinical cardiovascular health. The health benefits of other types of face coverings have not been tested and their effectiveness in reducing exposure is highly variable, depends largely on fit, and is unrelated to cost. Behavior modifications may reduce exposure, but there has been little research on health impacts. There is now substantial evidence that HEPA filter air purifiers reduce indoor PM2.5 concentrations and improve subclinical health indicators. As a result, their use is being recommended by a growing number of government and public health organizations. Several studies have also reported subclinical cardiovascular health benefits from well-fitting respirators, while evidence of health benefits from other types of facemasks and behavior changes remains very limited. In situations when emissions cannot be controlled at the source, such as during forest fires, individual- or household-level interventions may be the primary option. In most cases, however, such interventions should be supplemental to emission reduction efforts that benefit entire communities.
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Affiliation(s)
- Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada.
| | - Prabjit Barn
- Legacy for Airway Health, Vancouver Coastal Health, Vancouver, BC, Canada
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11
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Barn P, Gombojav E, Ochir C, Boldbaatar B, Beejin B, Naidan G, Galsuren J, Legtseg B, Byambaa T, Hutcheon JA, Janes C, Janssen PA, Lanphear BP, McCandless LC, Takaro TK, Venners SA, Webster GM, Palmer CD, Parsons PJ, Allen RW. Coal smoke, gestational cadmium exposure, and fetal growth. Environ Res 2019; 179:108830. [PMID: 31678728 DOI: 10.1016/j.envres.2019.108830] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 10/15/2019] [Accepted: 10/16/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Gestational cadmium exposure may impair fetal growth. Coal smoke has largely been unexplored as a source of cadmium exposure. We investigated the relationship between gestational cadmium exposure and fetal growth, and assessed coal smoke as a potential source of airborne cadmium, among non-smoking pregnant women in Ulaanbaatar, Mongolia, where coal combustion in home heating stoves is a major source of outdoor and indoor air pollution. METHODS This observational study was nested within the Ulaanbaatar Gestation and Air Pollution Research (UGAAR) study, a randomized controlled trial of portable high efficiency particulate air (HEPA) filter air cleaner use during pregnancy, fetal growth, and early childhood development. We measured third trimester blood cadmium concentrations in 374 out of 465 participants who had a live birth. We used multiple linear and logistic regression to assess the relationships between log2-transformed maternal blood cadmium concentrations and birth weight, length, head circumference, ponderal index, low birth weight, small for gestational age, and preterm birth in crude and adjusted models. We also evaluated the relationships between log2-transformed blood cadmium concentrations and the density of coal-burning stoves within 5000 m of each participant's apartment as a proxy of coal smoke emissions from home heating stoves. RESULTS The median (25th,75th percentile) blood cadmium concentration was 0.20 (0.15, 0.29) μg/L. A doubling of blood cadmium was associated with a 95 g (95% CI: 34, 155 g) reduction in birth weight in adjusted models. An interquartile range increase in coal stove density (from 3.4 to 4.9 gers/hectare) surrounding participants' apartments was associated with a 12.2% (95% CI: 0.3, 25.6%) increase in blood cadmium concentrations. CONCLUSIONS Gestational cadmium exposure was associated with reduced birth weight. In settings where coal is a widely used fuel, cadmium may play a role in the putative association between air pollution and impaired fetal growth.
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Affiliation(s)
- Prabjit Barn
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, Canada
| | - Enkhjargal Gombojav
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar, 14210, Mongolia
| | - Chimedsuren Ochir
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar, 14210, Mongolia
| | - Buyantushig Boldbaatar
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar, 14210, Mongolia
| | - Bolor Beejin
- Ministry of Health of Mongolia, Olympic Street-2, Government Building VIII, Sukhbaatar District, Ulaanbaatar, Mongolia
| | - Gerel Naidan
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar, 14210, Mongolia
| | - Jargalsaikhan Galsuren
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar, 14210, Mongolia
| | - Bayarkhuu Legtseg
- Sukhbaatar District Health Center, 11 Horoo, Tsagdaagiin Gudamj, Sukhbaatar District, Ulaanbaatar, Mongolia
| | - Tsogtbaatar Byambaa
- Ministry of Health of Mongolia, Olympic Street-2, Government Building VIII, Sukhbaatar District, Ulaanbaatar, Mongolia
| | - Jennifer A Hutcheon
- Faculty of Medicine, Department of Obstetrics & Gynaecology, University of British Columbia, 4500 Oak Street, Vancouver, V6H 2N1, Canada
| | - Craig Janes
- School of Public Health and Health Systems, University of Waterloo, 200 University Avenue West, Waterloo, N2L 3G1, Canada
| | - Patricia A Janssen
- School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver, V6T 1Z3, Canada
| | - Bruce P Lanphear
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, Canada
| | - Lawrence C McCandless
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, Canada
| | - Tim K Takaro
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, Canada
| | - Scott A Venners
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, Canada
| | - Glenys M Webster
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, Canada
| | - Christopher D Palmer
- New York State Department of Health, Wadsworth Center, Albany, NY, PO Box 509, 12201, USA; School of Public Health, University at Albany, State University of New York, One University Place, Rensselaer, NY, 12144, USA
| | - Patrick J Parsons
- New York State Department of Health, Wadsworth Center, Albany, NY, PO Box 509, 12201, USA; School of Public Health, University at Albany, State University of New York, One University Place, Rensselaer, NY, 12144, USA
| | - Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, Canada.
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Miller KA, Spalt EW, Gassett AJ, Curl CL, Larson TV, Avol E, Allen RW, Vedal S, Szpiro AA, Kaufman JD. Estimating ambient-origin PM 2.5 exposure for epidemiology: observations, prediction, and validation using personal sampling in the Multi-Ethnic Study of Atherosclerosis. J Expo Sci Environ Epidemiol 2019; 29:227-237. [PMID: 30166581 PMCID: PMC6380932 DOI: 10.1038/s41370-018-0053-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 03/26/2018] [Accepted: 04/08/2018] [Indexed: 05/19/2023]
Abstract
OBJECTIVES We aim to characterize the qualities of estimation approaches for individual exposure to ambient-origin fine particulate matter (PM2.5), for use in epidemiological studies. METHODS The analysis incorporates personal, home indoor, and home outdoor air monitoring data and spatio-temporal model predictions for 60 participants from the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). We compared measurement-based personal PM2.5 exposure with several measured or predicted estimates of outdoor, indoor, and personal exposures. RESULTS The mean personal 2-week exposure was 7.6 (standard deviation 3.7) µg/m3. Outdoor model predictions performed far better than outdoor concentrations estimated using a nearest-monitor approach (R = 0.63 versus R = 0.43). Incorporating infiltration indoors of ambient-derived PM2.5 provided better estimates of the measurement-based personal exposures than outdoor concentration predictions (R = 0.81 versus R = 0.63) and better scaling of estimated exposure (mean difference 0.4 versus 5.4 µg/m3 higher than measurements), suggesting there is value to collecting data regarding home infiltration. Incorporating individual-level time-location information into exposure predictions did not increase correlations with measurement-based personal exposures (R = 0.80) in our sample consisting primarily of retired persons. CONCLUSIONS This analysis demonstrates the importance of incorporating infiltration when estimating individual exposure to ambient air pollution. Spatio-temporal models provide substantial improvement in exposure estimation over a nearest monitor approach.
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Affiliation(s)
| | | | | | | | | | - Ed Avol
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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13
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Yuchi W, Gombojav E, Boldbaatar B, Galsuren J, Enkhmaa S, Beejin B, Naidan G, Ochir C, Legtseg B, Byambaa T, Barn P, Henderson SB, Janes CR, Lanphear BP, McCandless LC, Takaro TK, Venners SA, Webster GM, Allen RW. Evaluation of random forest regression and multiple linear regression for predicting indoor fine particulate matter concentrations in a highly polluted city. Environ Pollut 2019; 245:746-753. [PMID: 30500754 DOI: 10.1016/j.envpol.2018.11.034] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 11/01/2018] [Accepted: 11/11/2018] [Indexed: 05/14/2023]
Abstract
BACKGROUND Indoor and outdoor fine particulate matter (PM2.5) are both leading risk factors for death and disease, but making indoor measurements is often infeasible for large study populations. METHODS We developed models to predict indoor PM2.5 concentrations for pregnant women who were part of a randomized controlled trial of portable air cleaners in Ulaanbaatar, Mongolia. We used multiple linear regression (MLR) and random forest regression (RFR) to model indoor PM2.5 concentrations with 447 independent 7-day PM2.5 measurements and 87 potential predictor variables obtained from outdoor monitoring data, questionnaires, home assessments, and geographic data sets. We also developed blended models that combined the MLR and RFR approaches. All models were evaluated in a 10-fold cross-validation. RESULTS The predictors in the MLR model were season, outdoor PM2.5 concentration, the number of air cleaners deployed, and the density of gers (traditional felt-lined yurts) surrounding the apartments. MLR and RFR had similar performance in cross-validation (R2 = 50.2%, R2 = 48.9% respectively). The blended MLR model that included RFR predictions had the best performance (cross validation R2 = 81.5%). Intervention status alone explained only 6.0% of the variation in indoor PM2.5 concentrations. CONCLUSIONS We predicted a moderate amount of variation in indoor PM2.5 concentrations using easily obtained predictor variables and the models explained substantially more variation than intervention status alone. While RFR shows promise for modelling indoor concentrations, our results highlight the importance of out-of-sample validation when evaluating model performance. We also demonstrate the improved performance of blended MLR/RFR models in predicting indoor air pollution.
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Affiliation(s)
- Weiran Yuchi
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Enkhjargal Gombojav
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar, 14210, Mongolia
| | - Buyantushig Boldbaatar
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar, 14210, Mongolia
| | - Jargalsaikhan Galsuren
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar, 14210, Mongolia
| | - Sarangerel Enkhmaa
- Institute of Meteorology and Environmental Monitoring, Ministry of Environment of Mongolia, Mongolia
| | - Bolor Beejin
- Mongolian National Center for Public Health, Olympic Street 2, Ulaanbaatar, Mongolia
| | - Gerel Naidan
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar, 14210, Mongolia
| | - Chimedsuren Ochir
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar, 14210, Mongolia
| | - Bayarkhuu Legtseg
- Sukhbaatar District Health Center, 11 Horoo, Tsagdaagiin Gudamj, Sukhbaatar District, Ulaanbaatar, Mongolia
| | - Tsogtbaatar Byambaa
- Ministry of Health of Mongolia, Olympic Street-2, Government Building VIII, Sukhbaatar District, Ulaanbaatar, Mongolia
| | - Prabjit Barn
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Sarah B Henderson
- Environmental Health Services, British Columbia Centre for Disease Control, 655 W. 12th Ave, Vancouver, BC, V5T 4R4, Canada
| | - Craig R Janes
- School of Public Health and Health Systems, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada
| | - Bruce P Lanphear
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Lawrence C McCandless
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Tim K Takaro
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Scott A Venners
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Glenys M Webster
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
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14
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Barn P, Gombojav E, Ochir C, Boldbaatar B, Beejin B, Naidan G, Galsuren J, Legtseg B, Byambaa T, Hutcheon JA, Janes C, Janssen PA, Lanphear BP, McCandless LC, Takaro TK, Venners SA, Webster GM, Allen RW. The effect of portable HEPA filter air cleaner use during pregnancy on fetal growth: The UGAAR randomized controlled trial. Environ Int 2018; 121:981-989. [PMID: 30213473 DOI: 10.1016/j.envint.2018.08.036] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/19/2018] [Accepted: 08/15/2018] [Indexed: 05/22/2023]
Abstract
BACKGROUND Fine particulate matter (PM2.5) exposure may impair fetal growth. AIMS/OBJECTIVES Our aim was to assess the effect of portable high efficiency particulate air (HEPA) filter air cleaner use during pregnancy on fetal growth. METHODS The Ulaanbaatar Gestation and Air Pollution Research (UGAAR) study is a single-blind randomized controlled trial conducted in Ulaanbaatar, Mongolia. Non-smoking pregnant women recruited at ≤18 weeks gestation were randomized to an intervention (1-2 air cleaners in homes from early pregnancy until childbirth) or control (no air cleaners) group. Participants were not blinded to their intervention status. Demographic, health, and birth outcome data were obtained via questionnaires and clinic records. We used unadjusted linear and logistic regression and time-to-event analysis to evaluate the intervention. Our primary outcome was birth weight. Secondary outcomes were gestational age-adjusted birth weight, birth length, head circumference, gestational age at birth, and small for gestational age. The study is registered at ClinicalTrials.gov (NCT01741051). RESULTS We recruited 540 participants (272 control and 268 intervention) from January 9, 2014 to May 1, 2015. There were 465 live births and 28 losses to follow up. We previously reported a 29% (95% CI: 21, 37%) reduction in indoor PM2.5 concentrations with portable HEPA filter air cleaner use. The median (25th, 75th percentile) birth weights for control and intervention participants were 3450 g (3150, 3800 g) and 3550 g (3200, 3800 g), respectively (p = 0.34). The intervention was not associated with birth weight (18 g; 95% CI: -84, 120 g), but in a pre-specified subgroup analysis of 429 term births the intervention was associated with an 85 g (95% CI: 3, 167 g) increase in mean birth weight. CONCLUSIONS HEPA filter air cleaner use in a high pollution setting was associated with greater birth weight only among babies born at term.
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Affiliation(s)
- Prabjit Barn
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada.
| | - Enkhjargal Gombojav
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar 14210, Mongolia
| | - Chimedsuren Ochir
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar 14210, Mongolia
| | - Buyantushig Boldbaatar
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar 14210, Mongolia
| | - Bolor Beejin
- Ministry of Health of Mongolia, Olympic Street-2, Government building VIII, Sukhbaatar District, Ulaanbaatar, Mongolia
| | - Gerel Naidan
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar 14210, Mongolia
| | - Jargalsaikhan Galsuren
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar 14210, Mongolia
| | - Bayarkhuu Legtseg
- Sukhbaatar District Health Center, 11 Horoo, Tsagdaagiin Gudamj, Sukhbaatar District, Ulaanbaatar, Mongolia
| | - Tsogtbaatar Byambaa
- Ministry of Health of Mongolia, Olympic Street-2, Government building VIII, Sukhbaatar District, Ulaanbaatar, Mongolia
| | - Jennifer A Hutcheon
- Faculty of Medicine, Department of Obstetrics & Gynaecology, University of British Columbia, 4500 Oak Street, Vancouver V6H 2N1, Canada
| | - Craig Janes
- School of Public Health and Health Systems, University of Waterloo, 200 University Avenue West,Waterloo N2L 3G1, Canada
| | - Patricia A Janssen
- School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver V6T 1Z3, Canada
| | - Bruce P Lanphear
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada
| | - Lawrence C McCandless
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada
| | - Tim K Takaro
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada
| | - Scott A Venners
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada
| | - Glenys M Webster
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada
| | - Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada
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15
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Barn P, Gombojav E, Ochir C, Laagan B, Beejin B, Naidan G, Boldbaatar B, Galsuren J, Byambaa T, Janes C, Janssen PA, Lanphear BP, Takaro TK, Venners SA, Webster GM, Yuchi W, Palmer CD, Parsons PJ, Roh YM, Allen RW. The effect of portable HEPA filter air cleaners on indoor PM 2.5 concentrations and second hand tobacco smoke exposure among pregnant women in Ulaanbaatar, Mongolia: The UGAAR randomized controlled trial. Sci Total Environ 2018; 615:1379-1389. [PMID: 29751442 DOI: 10.1016/j.scitotenv.2017.09.291] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Revised: 09/20/2017] [Accepted: 09/27/2017] [Indexed: 05/22/2023]
Abstract
BACKGROUND Portable HEPA filter air cleaners can reduce indoor fine particulate matter (PM2.5), but their use has not been adequately evaluated in high pollution settings. We assessed air cleaner effectiveness in reducing indoor residential PM2.5 and second hand smoke (SHS) exposures among non-smoking pregnant women in Ulaanbaatar, Mongolia. METHODS We randomized 540 participants to an intervention group receiving 1 or 2 HEPA filter air cleaners or a control group receiving no air cleaners. We followed 259 intervention and 253 control participants to the end of pregnancy. We measured one-week indoor residential PM2.5 concentrations in early (~11weeks gestation) and late (~31weeks gestation) pregnancy and collected outdoor PM2.5 data from centrally-located government monitors. We assessed blood cadmium in late pregnancy. Hair nicotine was quantified in a subset (n=125) to evaluate blood cadmium as a biomarker of SHS exposure. We evaluated air cleaner effectiveness using mixed effects and multiple linear regression models and used stratified models and interaction terms to evaluate potential modifiers of effectiveness. RESULTS The overall geometric mean (GM) one-week outdoor PM2.5 concentration was 47.9μg/m3 (95% CI: 44.6, 51.6μg/m3), with highest concentrations in winter (118.0μg/m3; 110.4, 126.2μg/m3). One-week indoor and outdoor PM2.5 concentrations were correlated (r=0.69). Indoor PM2.5 concentrations were 29% (21, 37%) lower in intervention versus control apartments, with GMs of 17.3μg/m3 (15.8, 18.8μg/m3) and 24.5μg/m3 (22.2, 27.0μg/m3), respectively. Air cleaner effectiveness was greater when air cleaners were first deployed (40%; 31, 48%) than after approximately five months of use (15%; 0, 27%). Blood cadmium concentrations were 14% (4, 23%) lower among intervention participants, likely due to reduced SHS exposure. CONCLUSIONS Portable HEPA filter air cleaners can lower indoor PM2.5 concentrations and SHS exposures in highly polluted settings.
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Affiliation(s)
- Prabjit Barn
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada.
| | - Enkhjargal Gombojav
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar 14210, Mongolia.
| | - Chimedsuren Ochir
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar 14210, Mongolia.
| | - Bayarkhuu Laagan
- Sukhbaatar District Health Center, 11 Horoo, Tsagdaagiin Gudamj, Sukhbaatar District, Ulaanbaatar, Mongolia
| | - Bolor Beejin
- Mongolian National Center for Public Health, Olympic Street 2, Ulaanbaatar, Mongolia.
| | - Gerel Naidan
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar 14210, Mongolia
| | - Buyantushig Boldbaatar
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar 14210, Mongolia
| | - Jargalsaikhan Galsuren
- School of Public Health, Mongolian National University of Medical Sciences, Zorig Street, Ulaanbaatar 14210, Mongolia
| | - Tsogtbaatar Byambaa
- Mongolian National Center for Public Health, Olympic Street 2, Ulaanbaatar, Mongolia.
| | - Craig Janes
- School of Public Health and Health Systems, University of Waterloo, 200 University Avenue West, Waterloo N2L 3G1, Canada.
| | - Patricia A Janssen
- School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver V6T 1Z3, Canada.
| | - Bruce P Lanphear
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada.
| | - Tim K Takaro
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada.
| | - Scott A Venners
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada.
| | - Glenys M Webster
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada.
| | - Weiran Yuchi
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada.
| | - Christopher D Palmer
- New York State Department of Health, Wadsworth Center, Albany, NY, PO Box 509, 12201, USA; School of Public Health, University at Albany, State University of New York, One University Place, Rensselaer, NY 12144, USA.
| | - Patrick J Parsons
- New York State Department of Health, Wadsworth Center, Albany, NY, PO Box 509, 12201, USA; School of Public Health, University at Albany, State University of New York, One University Place, Rensselaer, NY 12144, USA.
| | - Young Man Roh
- College of Health Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, Canada.
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Barn PK, Elliott CT, Allen RW, Kosatsky T, Rideout K, Henderson SB. Portable air cleaners should be at the forefront of the public health response to landscape fire smoke. Environ Health 2016; 15:116. [PMID: 27887618 PMCID: PMC5124284 DOI: 10.1186/s12940-016-0198-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 11/19/2016] [Indexed: 05/26/2023]
Abstract
Landscape fires can produce large quantities of smoke that degrade air quality in both remote and urban communities. Smoke from these fires is a complex mixture of fine particulate matter and gases, exposure to which is associated with increased respiratory and cardiovascular morbidity and mortality. The public health response to short-lived smoke events typically advises people to remain indoors with windows and doors closed, but does not emphasize the use of portable air cleaners (PAC) to create private or public clean air shelters. High efficiency particulate air filters and electrostatic precipitators can lower indoor concentrations of fine particulate matter and improve respiratory and cardiovascular outcomes. We argue that PACs should be at the forefront of the public health response to landscape fire smoke events.
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Affiliation(s)
- Prabjit K. Barn
- Environmental Health Services, British Columbia Centre for Disease Control, 655 West 12th Avenue, Vancouver, BC V5Z 4R4 Canada
- National Collaborating Centre for Environmental Health, 200-601 West Broadway, Vancouver, BC V5Z 4C2 Canada
| | - Catherine T. Elliott
- Office of the Chief Medical Officer of Health, P.O. Box 2703, Whitehorse, Yukon Y1A 2C6 Canada
| | - Ryan W. Allen
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6 Canada
| | - Tom Kosatsky
- Environmental Health Services, British Columbia Centre for Disease Control, 655 West 12th Avenue, Vancouver, BC V5Z 4R4 Canada
- National Collaborating Centre for Environmental Health, 200-601 West Broadway, Vancouver, BC V5Z 4C2 Canada
| | - Karen Rideout
- Environmental Health Services, British Columbia Centre for Disease Control, 655 West 12th Avenue, Vancouver, BC V5Z 4R4 Canada
- National Collaborating Centre for Environmental Health, 200-601 West Broadway, Vancouver, BC V5Z 4C2 Canada
| | - Sarah B. Henderson
- Environmental Health Services, British Columbia Centre for Disease Control, 655 West 12th Avenue, Vancouver, BC V5Z 4R4 Canada
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MacNeill M, Dobbin N, St-Jean M, Wallace L, Marro L, Shin T, You H, Kulka R, Allen RW, Wheeler AJ. Can changing the timing of outdoor air intake reduce indoor concentrations of traffic-related pollutants in schools? Indoor Air 2016; 26:687-701. [PMID: 26340686 DOI: 10.1111/ina.12252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/23/2015] [Indexed: 05/22/2023]
Abstract
Traffic emissions have been associated with a wide range of adverse health effects. Many schools are situated close to major roads, and as children spend much of their day in school, methods to reduce traffic-related air pollutant concentrations in the school environment are warranted. One promising method to reduce pollutant concentrations in schools is to alter the timing of the ventilation so that high ventilation time periods do not correspond to rush hour traffic. Health Canada, in collaboration with the Ottawa-Carleton District School Board, tested the effect of this action by collecting traffic-related air pollution data from four schools in Ottawa, Canada, during October and November 2013. A baseline and intervention period was assessed in each school. There were statistically significant (P < 0.05) reductions in concentrations of most of the pollutants measured at the two late-start (9 AM start) schools, after adjusting for outdoor concentrations and the absolute indoor-outdoor temperature difference. The intervention at the early-start (8 AM start) schools did not have significant reductions in pollutant concentrations. Based on these findings, changing the timing of the ventilation may be a cost-effective mechanism of reducing traffic-related pollutants in late-start schools located near major roads.
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Affiliation(s)
- M MacNeill
- Air Health Science Division, Health Canada, Ottawa, ON, Canada.
| | - N Dobbin
- Air Health Science Division, Health Canada, Ottawa, ON, Canada
| | - M St-Jean
- Air Health Science Division, Health Canada, Ottawa, ON, Canada
| | | | - L Marro
- Population Studies Division, Health Canada, Ottawa, ON, Canada
| | - T Shin
- Air Health Science Division, Health Canada, Ottawa, ON, Canada
| | - H You
- Air Health Science Division, Health Canada, Ottawa, ON, Canada
| | - R Kulka
- Air Health Science Division, Health Canada, Ottawa, ON, Canada
| | - R W Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - A J Wheeler
- Air Health Science Division, Health Canada, Ottawa, ON, Canada
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Spalt EW, Curl CL, Allen RW, Cohen M, Williams K, Hirsch JA, Adar S, Kaufman JD. Factors influencing time-location patterns and their impact on estimates of exposure: the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). J Expo Sci Environ Epidemiol 2016; 26:341-8. [PMID: 25921081 PMCID: PMC4641036 DOI: 10.1038/jes.2015.26] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 02/25/2015] [Accepted: 02/26/2015] [Indexed: 05/03/2023]
Abstract
We assessed time-location patterns and the role of individual- and residential-level characteristics on these patterns within the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) cohort and also investigated the impact of individual-level time-location patterns on individual-level estimates of exposure to outdoor air pollution. Reported time-location patterns varied significantly by demographic factors such as age, gender, race/ethnicity, income, education, and employment status. On average, Chinese participants reported spending significantly more time indoors and less time outdoors and in transit than White, Black, or Hispanic participants. Using a tiered linear regression approach, we predicted time indoors at home and total time indoors. Our model, developed using forward-selection procedures, explained 43% of the variability in time spent indoors at home, and incorporated demographic, health, lifestyle, and built environment factors. Time-weighted air pollution predictions calculated using recommended time indoors from USEPA overestimated exposures as compared with predictions made with MESA Air participant-specific information. These data fill an important gap in the literature by describing the impact of individual and residential characteristics on time-location patterns and by demonstrating the impact of population-specific data on exposure estimates.
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Affiliation(s)
- Elizabeth W. Spalt
- Department of Environmental and Occupational Health Sciences, University of Washington
| | - Cynthia L. Curl
- Department of Environmental and Occupational Health Sciences, University of Washington
| | - Ryan W. Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Martin Cohen
- Department of Environmental and Occupational Health Sciences, University of Washington
| | - Kayleen Williams
- Collaborative Health Studies Coordinating Center, University of Washington
| | - Jana A. Hirsch
- Carolina Population Center, University of North Carolina, Chapel Hill, North Carolina
| | - Sara Adar
- Department of Epidemiology, University of Michigan, Ann Arbor, Michigan
| | - Joel D. Kaufman
- Departments of Environmental and Occupational Health Sciences, Epidemiology, and Medicine, University of Washington, Seattle, Washington
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Spalt EW, Curl CL, Allen RW, Cohen M, Adar SD, Stukovsky KH, Avol E, Castro-Diehl C, Nunn C, Mancera-Cuevas K, Kaufman JD. Time-location patterns of a diverse population of older adults: the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). J Expo Sci Environ Epidemiol 2016; 26:436. [PMID: 27305961 PMCID: PMC4913164 DOI: 10.1038/jes.2016.13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
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Spalt EW, Curl CL, Allen RW, Cohen M, Adar SD, Stukovsky KH, Avol E, Castro-Diehl C, Nunn C, Mancera-Cuevas K, Kaufman JD. Time-location patterns of a diverse population of older adults: the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). J Expo Sci Environ Epidemiol 2016; 26:349-55. [PMID: 25921083 PMCID: PMC4641054 DOI: 10.1038/jes.2015.29] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 02/25/2015] [Accepted: 02/26/2015] [Indexed: 05/18/2023]
Abstract
The primary aim of this analysis was to present and describe questionnaire data characterizing time-location patterns of an older, multiethnic population from six American cities. We evaluated the consistency of results from repeated administration of this questionnaire and between this questionnaire and other questionnaires collected from participants of the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). Participants reported spending most of their time inside their homes (average: 121 h/week or 72%). More than 50% of the participants reported spending no time in several of the location options, including at home outdoors, at work/volunteer/school locations indoors or outdoors, or in "other" locations outdoors. We observed consistency between self-reported time-location patterns from repeated administration of the time-location questionnaire and compared with other survey instruments. Comparisons with national cohorts demonstrated the differences in time-location patterns in the MESA Air cohort due to differences in demographics, but the data showed similar trends in patterns by age, gender, season, and employment status. This study was the first to explicitly examine the time-location patterns in an older, multiethnic population and the first to add data on Chinese participants. These data can be used to inform future epidemiological research of MESA Air and other studies that include diverse populations.
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Affiliation(s)
- Elizabeth W. Spalt
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
| | - Cynthia L. Curl
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
| | - Ryan W. Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Martin Cohen
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
| | - Sara D. Adar
- Department of Epidemiology, University of Michigan, Ann Arbor, Michigan
| | | | - Ed Avol
- Department of Preventive Medicine, University of Southern California, Los Angeles, California
| | | | - Cathy Nunn
- Division of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North Carolina
| | | | - Joel D. Kaufman
- Departments of Environmental and Occupational Health Sciences, Epidemiology, and Medicine, University of Washington, Seattle, Washington
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21
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Spalt EW, Curl CL, Allen RW, Cohen M, Williams K, Hirsch JA, Adar SD, Kaufman JD. Factors influencing time-location patterns and their impact on estimates of exposure: the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). J Expo Sci Environ Epidemiol 2016; 26:435. [PMID: 27305960 PMCID: PMC4913163 DOI: 10.1038/jes.2016.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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Takaro TK, Scott JA, Allen RW, Anand SS, Becker AB, Befus AD, Brauer M, Duncan J, Lefebvre DL, Lou W, Mandhane PJ, McLean KE, Miller G, Sbihi H, Shu H, Subbarao P, Turvey SE, Wheeler AJ, Zeng L, Sears MR, Brook JR. The Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort study: assessment of environmental exposures. J Expo Sci Environ Epidemiol 2015; 25:580-92. [PMID: 25805254 PMCID: PMC4611361 DOI: 10.1038/jes.2015.7] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 12/15/2014] [Indexed: 05/23/2023]
Abstract
The Canadian Healthy Infant Longitudinal Development birth cohort was designed to elucidate interactions between environment and genetics underlying development of asthma and allergy. Over 3600 pregnant mothers were recruited from the general population in four provinces with diverse environments. The child is followed to age 5 years, with prospective characterization of diverse exposures during this critical period. Key exposure domains include indoor and outdoor air pollutants, inhalation, ingestion and dermal uptake of chemicals, mold, dampness, biological allergens, pets and pests, housing structure, and living behavior, together with infections, nutrition, psychosocial environment, and medications. Assessments of early life exposures are focused on those linked to inflammatory responses driven by the acquired and innate immune systems. Mothers complete extensive environmental questionnaires including time-activity behavior at recruitment and when the child is 3, 6, 12, 24, 30, 36, 48, and 60 months old. House dust collected during a thorough home assessment at 3-4 months, and biological specimens obtained for multiple exposure-related measurements, are archived for analyses. Geo-locations of homes and daycares and land-use regression for estimating traffic-related air pollution complement time-activity-behavior data to provide comprehensive individual exposure profiles. Several analytical frameworks are proposed to address the many interacting exposure variables and potential issues of co-linearity in this complex data set.
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Affiliation(s)
- Tim K Takaro
- Simon Fraser University, Vancouver, British Columbia, Canada
| | | | - Ryan W Allen
- Simon Fraser University, Vancouver, British Columbia, Canada
| | | | | | - A Dean Befus
- University of Alberta, Edmonton, Alberta, Canada
| | - Michael Brauer
- University of British Columbia, Vancouver, British Columbia, Canada
| | | | | | - Wendy Lou
- University of Toronto, Toronto, Ontario, Canada
| | | | | | | | - Hind Sbihi
- University of British Columbia, Vancouver, British Columbia, Canada
| | - Huan Shu
- Simon Fraser University, Vancouver, British Columbia, Canada
- Karlstad University, Karlstad, Värmland, Sweden
| | - Padmaja Subbarao
- University of Toronto, Toronto, Ontario, Canada
- Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stuart E Turvey
- University of British Columbia, Vancouver, British Columbia, Canada
| | - Amanda J Wheeler
- Edith Cowan University, Joondalup, Western Australia, Australia
- Health Canada, Ottawa, Ontario, Canada
| | - Leilei Zeng
- University of Waterloo, Waterloo, Ontario, Canada
| | | | - Jeffrey R Brook
- University of Toronto, Toronto, Ontario, Canada
- Environment Canada, Toronto, Ontario, Canada
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Sbihi H, Allen RW, Becker A, Brook JR, Mandhane P, Scott JA, Sears MR, Subbarao P, Takaro TK, Turvey SE, Brauer M. Perinatal Exposure to Traffic-Related Air Pollution and Atopy at 1 Year of Age in a Multi-Center Canadian Birth Cohort Study. Environ Health Perspect 2015; 123:902-8. [PMID: 25826816 PMCID: PMC4559953 DOI: 10.1289/ehp.1408700] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 03/26/2015] [Indexed: 05/22/2023]
Abstract
BACKGROUND The role of traffic-related air pollution (TRAP) exposure in the development of allergic sensitization in children is unclear, and few birth cohort studies have incorporated spatiotemporal exposure assessment. OBJECTIVES We aimed to examine the association between TRAP and atopy in 1-year-old children from an ongoing national birth cohort study in four Canadian cities. METHODS We identified 2,477 children of approximately 1 year of age with assessment of atopy for inhalant (Alternaria, Der p, Der f, cat, dog, cockroach) and food-related (milk, eggs, peanuts, soy) allergens. Exposure to nitrogen dioxide (NO2) was estimated from city-specific land use regression models accounting for residential mobility and temporal variability in ambient concentrations. We used mixed models to examine associations between atopy and exposure during pregnancy and the first year of life, including adjustment for covariates (maternal atopy, socioeconomic status, pets, mold, nutrition). We also conducted analyses stratified by time-location patterns, daycare attendance, and modeled home ventilation. RESULTS Following spatiotemporal adjustment, TRAP exposure after birth increased the risk for development of atopy to any allergens [adjusted odds ratio (aOR) per 10 μg/m3 NO2 = 1.16; 95% CI: 1.00, 1.41], but not during pregnancy (aOR = 1.02; 95% CI: 0.86, 1.22). This association was stronger among children not attending daycare (aOR = 1.61; 95% CI: 1.28, 2.01) compared with daycare attendees (aOR = 1.05; 95% CI: 0.81, 1.28). Trends to increased risk were also found for food (aOR = 1.17; 95% CI: 0.95, 1.47) and inhalant allergens (aOR = 1.28; 95% CI: 0.93, 1.76). CONCLUSION Using refined exposure estimates that incorporated temporal variability and residential mobility, we found that traffic-related air pollution during the first year of life was associated with atopy. CITATION Sbihi H, Allen RW, Becker A, Brook JR, Mandhane P, Scott JA, Sears MR, Subbarao P, Takaro TK, Turvey SE, Brauer M. 2015. Perinatal exposure to traffic-related air pollution and atopy at 1 year of age in a multi-center Canadian birth cohort study. Environ Health Perspect 123:902-908; http://dx.doi.org/10.1289/ehp.1408700.
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Affiliation(s)
- Hind Sbihi
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
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24
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Crouse DL, Peters PA, Villeneuve PJ, Proux MO, Shin HH, Goldberg MS, Johnson M, Wheeler AJ, Allen RW, Atari DO, Jerrett M, Brauer M, Brook JR, Cakmak S, Burnett RT. Within- and between-city contrasts in nitrogen dioxide and mortality in 10 Canadian cities; a subset of the Canadian Census Health and Environment Cohort (CanCHEC). J Expo Sci Environ Epidemiol 2015; 25:482-9. [PMID: 25605445 PMCID: PMC4542139 DOI: 10.1038/jes.2014.89] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 10/27/2014] [Accepted: 10/31/2014] [Indexed: 05/21/2023]
Abstract
The independent and joint effects of within- and between-city contrasts in air pollution on mortality have been investigated rarely. To examine the differential effects of between- versus within-city contrasts in pollution exposure, we used both ambient measurements and land use regression models to assess associations with mortality and exposure to nitrogen dioxide (NO2) among ~735,600 adults in 10 of the largest Canadian cities. We estimated exposure contrasts partitioned into within- and between-city contrasts, and the sum of these as overall exposures, for every year from 1984 to 2006. Residential histories allowed us to follow subjects annually during the study period. We calculated hazard ratios (HRs) adjusted for many personal and contextual variables. In fully-adjusted, random-effects models, we found positive associations between overall NO2 exposures and mortality from non-accidental causes (HR per 5 p.p.b.: 1.05; 95% confidence interval (CI): 1.03-1.07), cardiovascular disease (HR per 5 p.p.b.: 1.04; 95% CI: 1.01-1.06), ischaemic heart disease (HR per 5 p.p.b.: 1.05; 95% CI: 1.02-1.08) and respiratory disease (HR per 5 p.p.b.: 1.04; 95% CI: 0.99-1.08), but not from cerebrovascular disease (HR per 5 p.p.b.: 1.01; 95% CI: 0.96-1.06). We found that most of these associations were determined by within-city contrasts, as opposed to by between-city contrasts in NO2. Our results suggest that variation in NO2 concentrations within a city may represent a more toxic mixture of pollution than variation between cities.
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Affiliation(s)
- Dan L Crouse
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
- Environmental Health Science and Research Bureau, Health Canada, 50 Columbine Driveway, Tunney's Pasture, Ottawa, ON K1A 0K9, Canada. Tel.: +613 941 5161. Fax: +613 941 3883. E-mail:
| | - Paul A Peters
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
- Department of Sociology, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Paul J Villeneuve
- Institute of Health Science, Technology and Policy, Carleton University, Ottawa, Ontario, Canada
| | | | - Hwashin H Shin
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Mark S Goldberg
- Department of Medicine, McGill University, Montreal, Québec, Canada
- Division of Clinical Epidemiology, McGill University Health Centre, Montreal, Québec, Canada
| | - Markey Johnson
- Air Health Science Division, Health Canada, Ottawa, Ontario, Canada
| | - Amanda J Wheeler
- Air Health Science Division, Health Canada, Ottawa, Ontario, Canada
| | - Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Dominic Odwa Atari
- Faculty of Arts & Science, Nipissing University, North Bay, Ontario, Canada
| | - Michael Jerrett
- School of Public Health, University of California, Berkeley, California, USA
| | - Michael Brauer
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jeffrey R Brook
- Air Quality Research Division, Environment Canada, Toronto, Ontario, Canada
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Sabit Cakmak
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Richard T Burnett
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
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Kajbafzadeh M, Brauer M, Karlen B, Carlsten C, van Eeden S, Allen RW. The impacts of traffic-related and woodsmoke particulate matter on measures of cardiovascular health: a HEPA filter intervention study. Occup Environ Med 2015; 72:394-400. [PMID: 25896330 DOI: 10.1136/oemed-2014-102696] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 03/25/2015] [Indexed: 01/05/2023]
Abstract
BACKGROUND Combustion-generated fine particulate matter (PM2.5) is associated with cardiovascular morbidity. Both traffic-related air pollution and residential wood combustion may be important, but few studies have compared their impacts. OBJECTIVES To assess and compare effects of traffic-related and woodsmoke PM2.5 on endothelial function and systemic inflammation (C reactive protein, interleukin-6 and band cells) among healthy adults in Vancouver, British Columbia, Canada, using high efficiency particulate air (HEPA) filtration to introduce indoor PM2.5 exposure gradients. METHODS We recruited 83 healthy adults from 44 homes in traffic-impacted or woodsmoke-impacted areas to participate in this randomised, single-blind cross-over intervention study. PM2.5 concentrations were measured during two consecutive 7-day periods, one with filtration and the other with 'placebo filtration'. Endothelial function and biomarkers of systematic inflammation were measured at the end of each 7-day period. RESULTS HEPA filtration was associated with a 40% decrease in indoor PM2.5 concentrations. There was no relationship between PM2.5 exposure and endothelial function. There was evidence of an association between indoor PM2.5 and C reactive protein among those in traffic-impacted locations (42.1% increase in C reactive protein per IQR increase in indoor PM2.5, 95% CI 1.2% to 99.5%), but not among those in woodsmoke-impacted locations. There were no associations with interleukin-6 or band cells. CONCLUSIONS Evidence of an association between C reactive protein and indoor PM2.5 among healthy adults in traffic-impacted areas is consistent with the hypothesis that traffic-related particles, even at relatively low concentrations, play an important role in the cardiovascular effects of the urban PM mixture. TRIAL REGISTRATION NUMBER http://www.clinicaltrials.gov (NCT01570062).
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Affiliation(s)
- Majid Kajbafzadeh
- School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael Brauer
- School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Barbara Karlen
- School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Chris Carlsten
- School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Stephan van Eeden
- Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
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Semmens EO, Noonan CW, Allen RW, Weiler EC, Ward TJ. Indoor particulate matter in rural, wood stove heated homes. Environ Res 2015; 138:93-100. [PMID: 25701812 PMCID: PMC4385435 DOI: 10.1016/j.envres.2015.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 02/01/2015] [Accepted: 02/03/2015] [Indexed: 05/08/2023]
Abstract
Ambient particulate matter (PM) exposures have adverse impacts on public health, but research evaluating indoor PM concentrations in rural homes in the United States using wood as fuel for heating is limited. Our objectives were to characterize indoor PM mass and particle number concentrations (PNCs), quantify infiltration of outdoor PM into the indoor environment, and investigate potential predictors of concentrations and infiltration in 96 homes in the northwestern US and Alaska using wood stoves as the primary source of heating. During two forty-eight hour sampling periods during the pre-intervention winter of a randomized trial, we assessed PM mass (<2.5μm) and PNCs (particles/cm(3)) in six size fractions (0.30-0.49, 0.50-0.99, 1.00-2.49, 2.5-5.0, 5.0-10.0, 10.0+μm). Daily mean (sd) PM2.5 concentrations were 28.8 (28.5)μg/m(3) during the first sampling period and 29.1 (30.1)μg/m(3) during the second period. In repeated measures analyses, household income was inversely associated with PM2.5 and smaller size fraction PNCs, in particular. Time of day was a significant predictor of indoor and outdoor PM2.5 concentrations, and infiltration efficiency was relatively low (Finf (sd)=0.27 (0.20)). Our findings demonstrate relatively high mean PM concentrations in these wood burning homes and suggest potential targets for interventions for improving indoor air quality and health in rural settings.
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Affiliation(s)
- Erin O Semmens
- Department of Biomedical and Pharmaceutical Sciences, Center for Environmental Health Sciences, 32 Campus Drive, The University of Montana, Missoula, MT 59812, USA.
| | - Curtis W Noonan
- Department of Biomedical and Pharmaceutical Sciences, Center for Environmental Health Sciences, 32 Campus Drive, The University of Montana, Missoula, MT 59812, USA.
| | - Ryan W Allen
- Faculty of Health Sciences, 8888 University Drive, Simon Fraser University, Burnaby, BC, Canada V5A 1S6.
| | - Emily C Weiler
- Department of Biomedical and Pharmaceutical Sciences, Center for Environmental Health Sciences, 32 Campus Drive, The University of Montana, Missoula, MT 59812, USA.
| | - Tony J Ward
- Department of Biomedical and Pharmaceutical Sciences, Center for Environmental Health Sciences, 32 Campus Drive, The University of Montana, Missoula, MT 59812, USA.
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Affiliation(s)
- Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Prabjit K Barn
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Bruce P Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada; Child and Family Research Institute, BC Children's Hospital, Vancouver, British Columbia, Canada
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Gan WQ, Allen RW, Brauer M, Davies HW, Mancini GBJ, Lear SA. Long-term exposure to traffic-related air pollution and progression of carotid artery atherosclerosis: a prospective cohort study. BMJ Open 2014; 4:e004743. [PMID: 24710134 PMCID: PMC3987708 DOI: 10.1136/bmjopen-2013-004743] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVES Epidemiological studies have demonstrated associations between long-term exposure to traffic-related air pollution and coronary heart disease (CHD). Atherosclerosis is the principal pathological process responsible for CHD events, but effects of traffic-related air pollution on progression of atherosclerosis are not clear. This study aimed to investigate associations between long-term exposure to traffic-related air pollution and progression of carotid artery atherosclerosis. SETTING Healthy volunteers in metropolitan Vancouver, Canada. PARTICIPANTS AND OUTCOME MEASURES 509 participants aged 30-65 years were recruited and followed for approximately 5 years. At baseline and end of follow-up, participants underwent carotid artery ultrasound examinations to assess atherosclerosis severity, including carotid intima-media thickness, plaque area, plaque number and total area. Annual change of each atherosclerosis marker during the follow-up period was calculated as the difference between these two measurements divided by years of follow-up. Living close to major roads was defined as ≤150 m from a highway or ≤50 m from a major road. Residential exposures to traffic-related air pollutants including black carbon, fine particles, nitrogen dioxide and nitric oxide were estimated using high-resolution land-use regression models. The data were analysed using general linear models adjusting for various covariates. RESULTS At baseline, there were no significant differences in any atherosclerosis markers between participants living close to and those living away from major roads. After follow-up, the differences in annual changes of these markers between these two groups were small and not statistically significant. Also, no significant associations were observed with concentrations of traffic-related air pollutants including black carbon, fine particles, nitrogen dioxide and nitric oxide. CONCLUSIONS This study did not find significant associations between traffic-related air pollution and progression of carotid artery atherosclerosis in a region with lower levels and smaller contrasts of ambient air pollution.
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Affiliation(s)
- Wen Qi Gan
- Department of Population Health, Hofstra North Shore-LIJ School of Medicine, Great Neck, New York, USA
- Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Great Neck, New York, USA
| | - Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Michael Brauer
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hugh W Davies
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - G B John Mancini
- Healthy Heart Program, St Paul Hospital, Providence Healthcare, Vancouver, British Columbia, Canada
- Faculty of Medicine, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Scott A Lear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
- Division of Cardiology, Providence Health Care, Vancouver, British Columbia, Canada
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Phung OJ, Schwartzman E, Allen RW, Engel SS, Rajpathak SN. Sulphonylureas and risk of cardiovascular disease: systematic review and meta-analysis. Diabet Med 2013; 30:1160-71. [PMID: 23663156 DOI: 10.1111/dme.12232] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/08/2013] [Indexed: 12/13/2022]
Abstract
AIMS Sulphonylurea use has been linked with increased cardiovascular disease risk; however, previous studies have been inconsistent. Type 2 diabetes independently increases risk for cardiovascular disease, so understanding the link between longer-term use of anti-diabetic medications and cardiovascular disease has important clinical implications. METHODS Literature search in MEDLINE and CENTRAL was conducted throughout December 2011 for clinical and observational studies that reported the association between sulphonylurea and cardiovascular disease events. Ratios (relative risk, odds ratios or hazard ratios) adjusted for potential confounders (concomitant medications, baseline cardiovascular risk, diabetes severity) were pooled using a random-effects model to yield relative risks and associated 95% confidence intervals. RESULTS This meta-analysis included 33 studies (n = 1,325,446 patients), followed for a range of 0.46-10.4 years. In all studies, compared with other oral diabetes drugs, sulphonylurea use was associated with a significantly increased risk of cardiovascular death (relative risk 1.27, 95% confidence interval 1.18-1.34, n = 27 comparisons) and composite cardiovascular event (including myocardial infarction, stroke, cardiovascular-related hospitalization or cardiovascular death) (relative risk 1.10, 95% confidence interval 1.04-1.16, n = 43 comparisons). In studies comparing sulphonylurea vs. metformin, these relative risks were 1.26 (95% confidence interval 1.17-1.35, n = 17 comparisons) and 1.18 (95%confidence interval 1.13-1.24, n = 16 comparisons), respectively. CONCLUSIONS Results suggest that sulphonylurea use may elevate the risk of cardiovascular disease among patients with diabetes. This meta-analysis expands the pool of studies evaluating cardiovascular mortality compared with prior observations while using adjusted estimates, and assessing an additional outcome of a composite cardiovascular event. This finding warrants consideration in clinical practice when other treatment options may be available.
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Affiliation(s)
- O J Phung
- Western University of Health Sciences, College of Pharmacy, Pomona; Western Diabetes Institute, Pomona, CA
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Sbihi H, Brook JR, Allen RW, Curran JH, Dell S, Mandhane P, Scott JA, Sears MR, Subbarao P, Takaro TK, Turvey SE, Wheeler AJ, Brauer M. A new exposure metric for traffic-related air pollution? An analysis of determinants of hopanes in settled indoor house dust. Environ Health 2013; 12:48. [PMID: 23782977 PMCID: PMC3711892 DOI: 10.1186/1476-069x-12-48] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 06/12/2013] [Indexed: 05/30/2023]
Abstract
BACKGROUND Exposure to traffic-related air pollution (TRAP) can adversely impact health but epidemiologic studies are limited in their abilities to assess long-term exposures and incorporate variability in indoor pollutant infiltration. METHODS In order to examine settled house dust levels of hopanes, engine lubricating oil byproducts found in vehicle exhaust, as a novel TRAP exposure measure, dust samples were collected from 171 homes in five Canadian cities and analyzed by gas chromatography-mass spectrometry. To evaluate source contributions, the relative abundance of the highest concentration hopane monomer in house dust was compared to that in outdoor air. Geographic variables related to TRAP emissions and outdoor NO2 concentrations from city-specific TRAP land use regression (LUR) models were calculated at each georeferenced residence location and assessed as predictors of variability in dust hopanes. RESULTS Hopanes relative abundance in house dust and ambient air were significantly correlated (Pearson's r=0.48, p<0.05), suggesting that dust hopanes likely result from traffic emissions. The proportion of variance in dust hopanes concentrations explained by LUR NO2 was less than 10% in Vancouver, Winnipeg and Toronto while the correlations in Edmonton and Windsor explained 20 to 40% of the variance. Modeling with household factors such as air conditioning and shoe removal along with geographic predictors related to TRAP generally increased the proportion of explained variability (10-80%) in measured indoor hopanes dust levels. CONCLUSIONS Hopanes can consistently be detected in house dust and may be a useful tracer of TRAP exposure if determinants of their spatiotemporal variability are well-characterized, and when home-specific factors are considered.
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Affiliation(s)
- Hind Sbihi
- School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver, BC, Canada V6T 1Z3
| | - Jeffrey R Brook
- Air Quality Research Division, Environment Canada, 4905 Dufferin Street, Toronto, Ontario, Canada M3H 5T4
| | - Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada V5A 1S6
| | - Jason H Curran
- School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver, BC, Canada V6T 1Z3
| | - Sharon Dell
- Division of Respiratory Medicine, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8
| | - Piush Mandhane
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, WC Mackenzie Health Sciences Centre, Edmonton, Alberta T6G 2R7, Canada
| | - James A Scott
- Dalla Lana School of Public Health, University of Toronto, 155 College St, Toronto ON M5T 3M7, Canada
| | - Malcolm R Sears
- Department of Medicine, Faculty of Health Sciences, McMaster University, 1280 Main St W, Hamilton ON L8S 4K1, Canada
| | - Padmaja Subbarao
- Division of Respiratory Medicine, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8
| | - Timothy K Takaro
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada V5A 1S6
| | - Stuart E Turvey
- BC Children’s Hospital and Child & Family Research Institute, 950 West 28th Ave, Vancouver, BC, Canada V5Z 4H4
| | - Amanda J Wheeler
- Air Health Science Division, Health Canada, 269 Laurier Avenue West, Ottawa, Ontario, Canada K1A 0K9
| | - Michael Brauer
- School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver, BC, Canada V6T 1Z3
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Abernethy RC, Allen RW, McKendry IG, Brauer M. A land use regression model for ultrafine particles in Vancouver, Canada. Environ Sci Technol 2013; 47:5217-25. [PMID: 23550900 DOI: 10.1021/es304495s] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Methods to characterize chronic exposure to ultrafine particles (UFP) can help to clarify potential health effects. Since UFP are not routinely monitored in North America, spatiotemporal models are one potential exposure assessment methodology. Portable condensation particle counters were used to measure particle number concentrations (PNC) to develop a land use regression (LUR) model. PNC, wind speed and direction were measured for sixty minutes at eighty locations during a two-week sampling campaign. We conducted continuous monitoring at four additional locations to assess temporal variation. LUR modeling utilized 135 potential geographic predictors including: road length, vehicle density, restaurant density, population density, land use and others. A novel approach incorporated meteorological data through wind roses as alternates to traditional circular buffers. The range of measured (sixty-minute median) PNC across locations varied seventy-fold (1500-105000 particles/cm(3), mean [SD] = 18200 [15900] particles/cm(3)). Correlations between PNC and concurrently measured two-week average NOX concentrations were 0.6-0.7. A PNC LUR model (R(2) = 0.48, leave-one-out cross validation R(2) = 0.32) including truck route length within 50 m, restaurant density within 200 m, and ln-distance to the port represents the first UFP LUR model in North America. Models incorporating wind roses did not explain more variability in measured PNC.
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Affiliation(s)
- Rebecca C Abernethy
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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Johnson JYM, Rowe BH, Allen RW, Peters PA, Villeneuve PJ. A case-control study of medium-term exposure to ambient nitrogen dioxide pollution and hospitalization for stroke. BMC Public Health 2013; 13:368. [PMID: 23597019 PMCID: PMC3637065 DOI: 10.1186/1471-2458-13-368] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 04/02/2013] [Indexed: 01/04/2023] Open
Abstract
Background There are several plausible mechanisms whereby either short or long term exposure to pollution can increase the risk of stroke. Over the last decade, several studies have reported associations between short-term (day-to-day) increases in ambient air pollution and stroke. The findings from a smaller number of studies that have looked at long-term exposure to air pollution and stroke have been mixed. Most of these epidemiological studies have assigned exposure to air pollution based on place of residence, but these assignments are typically based on relatively coarse spatial resolutions. To date, few studies have evaluated medium-term exposures (i.e, exposures over the past season or year). To address this research gap, we evaluated associations between highly spatially resolved estimates of ambient nitrogen dioxide (NO2), a marker of traffic pollution, and emergency department visits for stroke in Edmonton, Canada. Methods This was a case-control study with cases defined as those who presented to an Edmonton area hospital emergency department between 2007 and 2009 with an acute ischemic stroke, hemorrhagic stroke, or transient ischemic attack. Controls were patients who presented to the same emergency departments for lacerations, sprains, or strains. A land-use regression model provided estimates of NO2 that were assigned to the place of residence. Logistic regression methods were used to estimate odds ratios for stroke in relation to an increase in the interquartile range of NO2 (5 ppb), adjusted for age, sex, meteorological variables, and neighborhood effects. Results The study included 4,696 stroke (cases) and 37,723 injury patients (controls). For all strokes combined, there was no association with NO2. Namely, the odds ratio associated with an interquartile increase in NO2 was 1.01 (95% confidence interval {CI}: 0.94-1.08). No associations were evident for any of the stroke subtypes examined. Conclusion When combined with our earlier work in Edmonton, our findings suggest that day-to-day fluctuations in air pollution increase the risk of ischemic stroke during the summer season, while medium term exposures are unrelated to stroke risk. The findings for medium term exposure should be interpreted cautiously due to limited individual-level risk factor data.
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Allen RW, Gombojav E, Barkhasragchaa B, Byambaa T, Lkhasuren O, Amram O, Takaro TK, Janes CR. An assessment of air pollution and its attributable mortality in Ulaanbaatar, Mongolia. Air Qual Atmos Health 2013; 6:137-150. [PMID: 23450113 PMCID: PMC3578716 DOI: 10.1007/s11869-011-0154-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 07/20/2011] [Indexed: 05/19/2023]
Abstract
Epidemiologic studies have consistently reported associations between outdoor fine particulate matter (PM2.5) air pollution and adverse health effects. Although Asia bears the majority of the public health burden from air pollution, few epidemiologic studies have been conducted outside of North America and Europe due in part to challenges in population exposure assessment. We assessed the feasibility of two current exposure assessment techniques, land use regression (LUR) modeling and mobile monitoring, and estimated the mortality attributable to air pollution in Ulaanbaatar, Mongolia. We developed LUR models for predicting wintertime spatial patterns of NO2 and SO2 based on 2-week passive Ogawa measurements at 37 locations and freely available geographic predictors. The models explained 74% and 78% of the variance in NO2 and SO2, respectively. Land cover characteristics derived from satellite images were useful predictors of both pollutants. Mobile PM2.5 monitoring with an integrating nephelometer also showed promise, capturing substantial spatial variation in PM2.5 concentrations. The spatial patterns in SO2 and PM, seasonal and diurnal patterns in PM2.5, and high wintertime PM2.5/PM10 ratios were consistent with a major impact from coal and wood combustion in the city's low-income traditional housing (ger) areas. The annual average concentration of PM2.5 measured at a centrally located government monitoring site was 75 μg/m3 or more than seven times the World Health Organization's PM2.5 air quality guideline, driven by a wintertime average concentration of 148 μg/m3. PM2.5 concentrations measured in a traditional housing area were higher, with a wintertime mean PM2.5 concentration of 250 μg/m3. We conservatively estimated that 29% (95% CI, 12-43%) of cardiopulmonary deaths and 40% (95% CI, 17-56%) of lung cancer deaths in the city are attributable to outdoor air pollution. These deaths correspond to nearly 10% of the city's total mortality, with estimates ranging to more than 13% of mortality under less conservative model assumptions. LUR models and mobile monitoring can be successfully implemented in developing country cities, thus cost-effectively improving exposure assessment for epidemiology and risk assessment. Air pollution represents a major threat to public health in Ulaanbaatar, Mongolia, and reducing home heating emissions in traditional housing areas should be the primary focus of air pollution control efforts.
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Affiliation(s)
- Ryan W. Allen
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6 Canada
| | - Enkhjargal Gombojav
- School of Public Health, Health Sciences University of Mongolia, Ulaanbaatar, Mongolia
| | | | - Tsogtbaatar Byambaa
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6 Canada
| | | | - Ofer Amram
- Department of Geography, Simon Fraser University, Burnaby, Canada
| | - Tim K. Takaro
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6 Canada
| | - Craig R. Janes
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6 Canada
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Kaufman JD, Adar SD, Allen RW, Barr RG, Budoff MJ, Burke GL, Casillas AM, Cohen MA, Curl CL, Daviglus ML, Diez Roux AV, Jacobs DR, Kronmal RA, Larson TV, Liu SLJ, Lumley T, Navas-Acien A, O'Leary DH, Rotter JI, Sampson PD, Sheppard L, Siscovick DS, Stein JH, Szpiro AA, Tracy RP. Prospective study of particulate air pollution exposures, subclinical atherosclerosis, and clinical cardiovascular disease: The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). Am J Epidemiol 2012; 176:825-37. [PMID: 23043127 DOI: 10.1093/aje/kws169] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) was initiated in 2004 to investigate the relation between individual-level estimates of long-term air pollution exposure and the progression of subclinical atherosclerosis and the incidence of cardiovascular disease (CVD). MESA Air builds on a multicenter, community-based US study of CVD, supplementing that study with additional participants, outcome measurements, and state-of-the-art air pollution exposure assessments of fine particulate matter, oxides of nitrogen, and black carbon. More than 7,000 participants aged 45-84 years are being followed for over 10 years for the identification and characterization of CVD events, including acute myocardial infarction and other coronary artery disease, stroke, peripheral artery disease, and congestive heart failure; cardiac procedures; and mortality. Subcohorts undergo baseline and follow-up measurements of coronary artery calcium using computed tomography and carotid artery intima-medial wall thickness using ultrasonography. This cohort provides vast exposure heterogeneity in ranges currently experienced and permitted in most developed nations, and the air monitoring and modeling methods employed will provide individual estimates of exposure that incorporate residence-specific infiltration characteristics and participant-specific time-activity patterns. The overarching study aim is to understand and reduce uncertainty in health effect estimation regarding long-term exposure to air pollution and CVD.
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Affiliation(s)
- Joel D Kaufman
- Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, USA.
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Allen RW, Adar SD, Avol E, Cohen M, Curl CL, Larson T, Liu LJS, Sheppard L, Kaufman JD. Modeling the residential infiltration of outdoor PM(2.5) in the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). Environ Health Perspect 2012; 120:824-30. [PMID: 22534026 PMCID: PMC3385439 DOI: 10.1289/ehp.1104447] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Accepted: 02/22/2012] [Indexed: 05/18/2023]
Abstract
BACKGROUND Epidemiologic studies of fine particulate matter [aerodynamic diameter ≤ 2.5 μm (PM(2.5))] typically use outdoor concentrations as exposure surrogates. Failure to account for variation in residential infiltration efficiencies (F(inf)) will affect epidemiologic study results. OBJECTIVE We aimed to develop models to predict F(inf) for > 6,000 homes in the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air), a prospective cohort study of PM(2.5) exposure, subclinical cardiovascular disease, and clinical outcomes. METHODS We collected 526 two-week, paired indoor-outdoor PM(2.5) filter samples from a subset of study homes. PM(2.5) elemental composition was measured by X-ray fluorescence, and F(inf) was estimated as the indoor/outdoor sulfur ratio. We regressed F(inf) on meteorologic variables and questionnaire-based predictors in season-specific models. Models were evaluated using the R² and root mean square error (RMSE) from a 10-fold cross-validation. RESULTS The mean ± SD F(inf) across all communities and seasons was 0.62 ± 0.21, and community-specific means ranged from 0.47 ± 0.15 in Winston-Salem, North Carolina, to 0.82 ± 0.14 in New York, New York. F(inf) was generally greater during the warm (> 18°C) season. Central air conditioning (AC) use, frequency of AC use, and window opening frequency were the most important predictors during the warm season; outdoor temperature and forced-air heat were the best cold-season predictors. The models predicted 60% of the variance in 2-week F(inf), with an RMSE of 0.13. CONCLUSIONS We developed intuitive models that can predict F(inf) using easily obtained variables. Using these models, MESA Air will be the first large epidemiologic study to incorporate variation in residential F(inf) into an exposure assessment.
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Affiliation(s)
- Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
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Amram O, Abernethy R, Brauer M, Davies H, Allen RW. Proximity of public elementary schools to major roads in Canadian urban areas. Int J Health Geogr 2011; 10:68. [PMID: 22188682 PMCID: PMC3283477 DOI: 10.1186/1476-072x-10-68] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 12/21/2011] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Epidemiologic studies have linked exposure to traffic-generated air and noise pollution with a wide range of adverse health effects in children. Children spend a large portion of time at school, and both air pollution and noise are elevated in close proximity to roads, so school location may be an important determinant of exposure. No studies have yet examined the proximity of schools to major roads in Canadian cities. METHODS Data on public elementary schools in Canada's 10 most populous cities were obtained from online databases. School addresses were geocoded and proximity to the nearest major road, defined using a standardized national road classification scheme, was calculated for each school. Based on measurements of nitrogen oxide concentrations, ultrafine particle counts, and noise levels in three Canadian cities we conservatively defined distances < 75 m from major roads as the zone of primary interest. Census data at the city and neighborhood levels were used to evaluate relationships between school proximity to major roads, urban density, and indicators of socioeconomic status. RESULTS Addresses were obtained for 1,556 public elementary schools, 95% of which were successfully geocoded. Across all 10 cities, 16.3% of schools were located within 75 m of a major road, with wide variability between cities. Schools in neighborhoods with higher median income were less likely to be near major roads (OR per $20,000 increase: 0.81; 95% CI: 0.65, 1.00), while schools in densely populated neighborhoods were more frequently close to major roads (OR per 1,000 dwellings/km²: 1.07; 95% CI: 1.00, 1.16). Over 22% of schools in the lowest neighborhood income quintile were close to major roads, compared to 13% of schools in the highest income quintile. CONCLUSIONS A substantial fraction of students at public elementary schools in Canada, particularly students attending schools in low income neighborhoods, may be exposed to elevated levels of air pollution and noise while at school. As a result, the locations of schools may negatively impact the healthy development and academic performance of a large number of Canadian children.
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Affiliation(s)
- Ofer Amram
- Department of Geography, Simon Fraser University, Burnaby, BC, Canada
| | - Rebecca Abernethy
- School of Population and Public Health, The University of British Columbia, Vancouver, BC, Canada
| | - Michael Brauer
- School of Population and Public Health, The University of British Columbia, Vancouver, BC, Canada
| | - Hugh Davies
- School of Population and Public Health, The University of British Columbia, Vancouver, BC, Canada
| | - Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
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Mercer LD, Szpiro AA, Sheppard L, Lindström J, Adar SD, Allen RW, Avol EL, Oron AP, Larson T, Liu LJS, Kaufman JD. Comparing universal kriging and land-use regression for predicting concentrations of gaseous oxides of nitrogen (NOx) for the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). Atmos Environ (1994) 2011; 45:4412-4420. [PMID: 21808599 PMCID: PMC3146303 DOI: 10.1016/j.atmosenv.2011.05.043] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
BACKGROUND: Epidemiological studies that assess the health effects of long-term exposure to ambient air pollution are used to inform public policy. These studies rely on exposure models that use data collected from pollution monitoring sites to predict exposures at subject locations. Land use regression (LUR) and universal kriging (UK) have been suggested as potential prediction methods. We evaluate these approaches on a dataset including measurements from three seasons in Los Angeles, CA. METHODS: The measurements of gaseous oxides of nitrogen (NOx) used in this study are from a "snapshot" sampling campaign that is part of the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). The measurements in Los Angeles were collected during three two-week periods in the summer, autumn, and winter, each with about 150 sites. The design included clusters of monitors on either side of busy roads to capture near-field gradients of traffic-related pollution. LUR and UK prediction models were created using geographic information system (GIS)-based covariates. Selection of covariates was based on 10-fold cross-validated (CV) R(2) and root mean square error (RMSE). Since UK requires specialized software, a computationally simpler two-step procedure was also employed to approximate fitting the UK model using readily available regression and GIS software. RESULTS: UK models consistently performed as well as or better than the analogous LUR models. The best CV R(2) values for season-specific UK models predicting log(NOx) were 0.75, 0.72, and 0.74 (CV RMSE 0.20, 0.17, and 0.15) for summer, autumn, and winter, respectively. The best CV R(2) values for season-specific LUR models predicting log(NOx) were 0.74, 0.60, and 0.67 (CV RMSE 0.20, 0.20, and 0.17). The two-stage approximation to UK also performed better than LUR and nearly as well as the full UK model with CV R(2) values 0.75, 0.70, and 0.70 (CV RMSE 0.20, 0.17, and 0.17) for summer, autumn, and winter, respectively. CONCLUSION: High quality LUR and UK prediction models for NOx in Los Angeles were developed for the three seasons based on data collected for MESA Air. In our study, UK consistently outperformed LUR. Similarly, the 2-step approach was more effective than the LUR models, with performance equal to or slightly worse than UK.
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Affiliation(s)
| | - Adam A Szpiro
- Department of Biostatistics, University of Washington
| | - Lianne Sheppard
- Department of Biostatistics, University of Washington
- Department of Environmental and Occupational Health Sciences, University of Washington
| | - Johan Lindström
- Centre for Mathematical Sciences, Lund University
- Department of Statistics, University of Washington
| | - Sara D Adar
- Department of Epidemiology, University of Michigan
| | - Ryan W Allen
- Simon Fraser University, Faculty of Health Sciences
| | - Edward L Avol
- Department of Preventive Medicine, University of Southern California
| | - Assaf P Oron
- Department of Environmental and Occupational Health Sciences, University of Washington
| | - Timothy Larson
- Department of Civil and Environmental Engineering, University of Washington
| | - L-J Sally Liu
- Department of Environmental and Occupational Health Sciences, University of Washington
| | - Joel D Kaufman
- Department of Environmental and Occupational Health Sciences, University of Washington
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Allen RW, Carlsten C, Karlen B, Leckie S, van Eeden S, Vedal S, Wong I, Brauer M. An air filter intervention study of endothelial function among healthy adults in a woodsmoke-impacted community. Am J Respir Crit Care Med 2011; 183:1222-30. [PMID: 21257787 DOI: 10.1164/rccm.201010-1572oc] [Citation(s) in RCA: 145] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Particulate air pollution is associated with cardiovascular morbidity. One hypothesized mechanism involves oxidative stress, systemic inflammation, and endothelial dysfunction. OBJECTIVES To assess an intervention's impact on particle exposures and endothelial function among healthy adults in a woodsmoke-impacted community. We also investigated the underlying role of oxidative stress and inflammation in relation to exposure reductions. METHODS Portable air filters were used in a randomized crossover intervention study of 45 healthy adults exposed to consecutive 7-day periods of filtered and nonfiltered air. MEASUREMENTS AND MAIN RESULTS Reactive hyperemia index was measured as an indicator of endothelial function via peripheral artery tonometry, and markers of inflammation (C-reactive protein, interleukin-6, and band cells) and lipid peroxidation (malondialdehyde and 8-iso-prostaglandin F(2α)) were quantified. Air filters reduced indoor fine particle concentrations by 60%. Filtration was associated with a 9.4% (95% confidence interval, 0.9-18%) increase in reactive hyperemia index and a 32.6% (4.4-60.9%) decrease in C-reactive protein. Decreases in particulate matter and the woodsmoke tracer levoglucosan were associated with reduced band cell counts. There was limited evidence of more pronounced effects on endothelial function and level of systemic inflammation among males, overweight participants, younger participants, and residents of wood-burning homes. No associations were noted for oxidative stress markers. CONCLUSIONS Air filtration was associated with improved endothelial function and decreased concentrations of inflammatory biomarkers but not markers of oxidative stress. Our results support the hypothesis that systemic inflammation and impaired endothelial function, both predictors of cardiovascular morbidity, can be favorably influenced by reducing indoor particle concentrations.
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Affiliation(s)
- Ryan W Allen
- Simon Fraser University, Faculty of Health Sciences, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
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Allen RW, Adar SD. Are both air pollution and noise driving adverse cardiovascular health effects from motor vehicles? Environ Res 2011; 111:184-5. [PMID: 21112051 DOI: 10.1016/j.envres.2010.11.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 11/10/2010] [Indexed: 05/24/2023]
Affiliation(s)
- Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada.
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Clark NA, Allen RW, Hystad P, Wallace L, Dell SD, Foty R, Dabek-Zlotorzynska E, Evans G, Wheeler AJ. Exploring variation and predictors of residential fine particulate matter infiltration. Int J Environ Res Public Health 2010; 7:3211-24. [PMID: 20948956 PMCID: PMC2954577 DOI: 10.3390/ijerph7083211] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 08/12/2010] [Accepted: 08/13/2010] [Indexed: 12/20/2022]
Abstract
Although individuals spend the majority of their time indoors, most epidemiological studies estimate personal air pollution exposures based on outdoor levels. This almost certainly results in exposure misclassification as pollutant infiltration varies between homes. However, it is often not possible to collect detailed measures of infiltration for individual homes in large-scale epidemiological studies and thus there is currently a need to develop models that can be used to predict these values. To address this need, we examined infiltration of fine particulate matter (PM(2.5)) and identified determinants of infiltration for 46 residential homes in Toronto, Canada. Infiltration was estimated using the indoor/outdoor sulphur ratio and information on hypothesized predictors of infiltration were collected using questionnaires and publicly available databases. Multiple linear regression was used to develop the models. Mean infiltration was 0.52 ± 0.21 with no significant difference across heating and non-heating seasons. Predictors of infiltration were air exchange, presence of central air conditioning, and forced air heating. These variables accounted for 38% of the variability in infiltration. Without air exchange, the model accounted for 26% of the variability. Effective modelling of infiltration in individual homes remains difficult, although key variables such as use of central air conditioning show potential as an easily attainable indicator of infiltration.
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Affiliation(s)
- Nina A. Clark
- Health Canada, 269 Laurier Ave West, Ottawa, Ontario K1A 0K9, Canada; E-Mail: (N.A.C.)
| | - Ryan W. Allen
- Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada; E-Mail: (R.W.A.)
| | - Perry Hystad
- University of British Columbia, 2206 East Mall, Vancouver, British Columbia V6T 1Z3, Canada; E-Mail: (P.H.)
| | - Lance Wallace
- 11568 Woodhollow Ct, Reston, VA 20191, USA; E-Mail: (L.W.)
| | - Sharon D. Dell
- The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada; E-Mail: (S.D.D.); (R.F.)
| | - Richard Foty
- The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada; E-Mail: (S.D.D.); (R.F.)
| | | | - Greg Evans
- University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada; E-Mail: (G.E)
| | - Amanda J. Wheeler
- Health Canada, 269 Laurier Ave West, Ottawa, Ontario K1A 0K9, Canada; E-Mail: (N.A.C.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-613-948-3686; Fax: +1-613-948-8482
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Doy N, McHale G, Newton MI, Hardacre C, Ge R, Macinnes JM, Kuvshinov D, Allen RW. Small volume laboratory on a chip measurements incorporating the quartz crystal microbalance to measure the viscosity-density product of room temperature ionic liquids. Biomicrofluidics 2010; 4:14107. [PMID: 20644676 PMCID: PMC2905273 DOI: 10.1063/1.3353379] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 02/10/2010] [Indexed: 05/15/2023]
Abstract
A microfluidic glass chip system incorporating a quartz crystal microbalance (QCM) to measure the square root of the viscosity-density product of room temperature ionic liquids (RTILs) is presented. The QCM covers a central recess on a glass chip, with a seal formed by tightly clamping from above outside the sensing region. The change in resonant frequency of the QCM allows for the determination of the square root viscosity-density product of RTILs to a limit of approximately 10 kg m(-2) s(-0.5). This method has reduced the sample size needed for characterization from 1.5 ml to only 30 mul and allows the measurement to be made in an enclosed system.
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Hystad PU, Setton EM, Allen RW, Keller PC, Brauer M. Modeling residential fine particulate matter infiltration for exposure assessment. J Expo Sci Environ Epidemiol 2009; 19:570-579. [PMID: 18716606 DOI: 10.1038/jes.2008.45] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Accepted: 06/09/2008] [Indexed: 05/26/2023]
Abstract
Individuals spend the majority of their time indoors; therefore, estimating infiltration of outdoor-generated fine particulate matter (PM(2.5)) can help reduce exposure misclassification in epidemiological studies. As indoor measurements in individual homes are not feasible in large epidemiological studies, we evaluated the potential of using readily available data to predict infiltration of ambient PM(2.5) into residences. Indoor and outdoor light scattering measurements were collected for 84 homes in Seattle, Washington, USA, and Victoria, British Columbia, Canada, to estimate residential infiltration efficiencies. Meteorological variables and spatial property assessment data (SPAD), containing detailed housing characteristics for individual residences, were compiled for both study areas using a geographic information system. Multiple linear regression was used to construct models of infiltration based on these data. Heating (October to February) and non-heating (March to September) season accounted for 36% of the yearly variation in detached residential infiltration. Two SPAD housing characteristic variables, low building value, and heating with forced air, predicted 37% of the variation found between detached residential infiltration during the heating season. The final model, incorporating temperature and the two SPAD housing characteristic variables, with a seasonal interaction term, explained 54% of detached residential infiltration. Residences with low building values had higher infiltration efficiencies than other residences, which could lead to greater exposure gradients between low and high socioeconomic status individuals than previously identified using only ambient PM(2.5) concentrations. This modeling approach holds promise for incorporating infiltration efficiencies into large epidemiology studies, thereby reducing exposure misclassification.
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Affiliation(s)
- Perry U Hystad
- Department of Geography, University of Victoria, Victoria, BC, Canada.
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Cohen MA, Adar SD, Allen RW, Avol E, Curl CL, Gould T, Hardie D, Ho A, Kinney P, Larson TV, Sampson P, Sheppard L, Stukovsky KD, Swan SS, Liu LJS, Kaufman JD. Approach to estimating participant pollutant exposures in the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). Environ Sci Technol 2009; 43:4687-93. [PMID: 19673252 PMCID: PMC2727607 DOI: 10.1021/es8030837] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Most published epidemiology studies of long-term air pollution health effects have relied on central site monitoring to investigate regional-scale differences in exposure. Few cohort studies have had sufficient data to characterize localized variations in pollution, despite the fact that large gradients can exist over small spatial scales. Similarly, previous data have generally been limited to measurements of particle mass or several of the criteria gases. The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) is an innovative investigation undertaken to link subclinical and clinical cardiovascular health effects with individual-level estimates of personal exposure to ambient-origin pollution. This project improves on prior work by implementing an extensive exposure assessment program to characterize long-term average concentrations of ambient-generated PM2.5, specific PM2.5 chemical components, and copollutants, with particular emphasis on capturing concentration gradients within cities. This paper describes exposure assessment in MESA Air, including questionnaires, community sampling, home monitoring, and personal sampling. Summary statistics describing the performance of the sampling methods are presented along with descriptive statistics of the air pollution concentrations by city.
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Affiliation(s)
- Martin A Cohen
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA.
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Allen RW, Criqui MH, Diez Roux AV, Allison M, Shea S, Detrano R, Sheppard L, Wong ND, Stukovsky KH, Kaufman JD. Fine particulate matter air pollution, proximity to traffic, and aortic atherosclerosis. Epidemiology 2009; 20:254-64. [PMID: 19129730 DOI: 10.1097/ede.0b013e31819644cc] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The initiation and acceleration of atherosclerosis is hypothesized as a physiologic mechanism underlying associations between air pollution and cardiovascular effects. Despite toxicologic evidence, epidemiologic data are limited. METHODS In this cross-sectional analysis we investigated exposure to fine particulate matter (PM2.5) and residential proximity to major roads in relation to abdominal aortic calcification, a sensitive indicator of systemic atherosclerosis. Aortic calcification was measured by computed tomography among 1147 persons, in 5 US metropolitan areas, enrolled in the Multi-Ethnic Study of Atherosclerosis. The presence and quantity of aortic calcification were modeled using relative risk regression and linear regression, respectively, with adjustment for potential confounders. RESULTS We observed a slightly elevated risk of aortic calcification (RR = 1.06; 95% confidence interval = 0.96-1.16) with a 10 microg/m contrast in PM2.5. The PM2.5-associated risk of aortic calcification was stronger among participants with long-term residence near a PM2.5 monitor (RR = 1.11; 1.00-1.24) and among participants not recently employed outside the home (RR = 1.10; 1.00-1.22). PM2.5 was not associated with an increase in the quantity of aortic calcification (Agatston score) and no roadway proximity effects were noted. There was indication of PM2.5 effect modification by lipid-lowering medication use, with greater effects among users, and PM2.5 associations were observed most consistently among Hispanics. CONCLUSIONS Although we did not find persuasive associations across our full study population, associations were stronger among participants with less exposure misclassification. These findings support the hypothesis of a relationship between particulate air pollution and systemic atherosclerosis.
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Affiliation(s)
- Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada.
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Allen RW, Davies H, Cohen MA, Mallach G, Kaufman JD, Adar SD. The spatial relationship between traffic-generated air pollution and noise in 2 US cities. Environ Res 2009; 109:334-42. [PMID: 19193368 PMCID: PMC3071639 DOI: 10.1016/j.envres.2008.12.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Revised: 12/03/2008] [Accepted: 12/12/2008] [Indexed: 05/21/2023]
Abstract
Traffic-generated air pollution and noise have both been linked to cardiovascular morbidity. Since traffic is a shared source, there is potential for correlated exposures that may lead to confounding in epidemiologic studies. As part of the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air), 2-week NO and NO(2) concentrations were measured at up to 105 locations, selected primarily to characterize gradients near major roads, in each of 9 US communities. We measured 5-min A-weighted equivalent continuous sound pressure levels (L(eq)) and ultrafine particle (UFP) counts at a subset of these NO/NO(2) monitoring locations in Chicago, IL (N=69 in December 2006; N=36 in April 2007) and Riverside County, CA (N=46 in April 2007). L(eq) and UFP were measured during non-"rush hour" periods (10:00-16:00) to maximize comparability between measurements. We evaluated roadway proximity exposure surrogates in relation to the measured levels, estimated noise-air pollution correlation coefficients, and evaluated the impact of regional-scale pollution gradients, wind direction, and roadway proximity on the correlations. Five-minute L(eq) measurements in December 2006 and April 2007 were highly correlated (r=0.84), and measurements made at different times of day were similar (coefficients of variation: 0.5-13%), indicating that 5-min measurements are representative of long-term L(eq). Binary and continuous roadway proximity metrics characterized L(eq) as well or better than NO or NO(2). We found strong regional-scale gradients in NO and NO(2), particularly in Chicago, but only weak regional-scale gradients in L(eq) and UFP. L(eq) was most consistently correlated with NO, but the correlations were moderate (0.20-0.60). After removing the influence of regional-scale gradients the correlations generally increased (L(eq)-NO: r=0.49-0.62), and correlations downwind of major roads (L(eq)-NO: r=0.53-0.74) were consistently higher than those upwind (0.35-0.65). There was not a consistent effect of roadway proximity on the correlations. In conclusion, roadway proximity variables are not unique exposure surrogates in studies of endpoints hypothesized to be related to both air pollution and noise. Moderate correlations between traffic-generated air pollution and noise suggest the possibility of confounding, which might be minimized by considering regional pollution gradients and/or prevailing wind direction(s) in epidemiologic studies.
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Affiliation(s)
- Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada.
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Crosland-Taylor PJ, Allen RW, England JM, Fielding JF, Lewis SM, Shinton NK, White JM. Draft protocol for testing calibration and quality control material used with automatic blood-counting apparatus. Clin Lab Haematol 2008; 1:61-4. [PMID: 535305 DOI: 10.1111/j.1365-2257.1979.tb00591.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A large number of commercial preparations are now available for calibrating or checking the stability of automatic blood counters. Most of these preparations are supplied with 'stated' values though the methods for assigning these values are not described in sufficient detail to allow for an adequate assessment of the validity. The Haemocytometry Panel of the British Committee for Standards in Haematology are therefore proposing a draft protocol for testing calibration and quality control materials. Comments on the draft protocol are invited, either as letters to the Editor of Clinical and Laboratory Haematology or in confidence to the Chairman of the Haemocytometry Panel.
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Allen RW, Mar T, Koenig J, Liu LJS, Gould T, Simpson C, Larson T. Changes in lung function and airway inflammation among asthmatic children residing in a woodsmoke-impacted urban area. Inhal Toxicol 2008; 20:423-33. [PMID: 18302050 DOI: 10.1080/08958370801903826] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Fine particulate matter (PM(2.5)) is associated with respiratory effects, and asthmatic children are especially sensitive. Preliminary evidence suggests that combustion-derived particles play an important role. Our objective was to evaluate effect estimates from different PM(2.5) exposure metrics in relation to airway inflammation and lung function among children residing in woodsmoke-impacted areas of Seattle. Nineteen children (ages 6-13 yr) with asthma were monitored during the heating season. We measured 24-h outdoor and personal concentrations of PM(2.5) and light-absorbing carbon (LAC). Levoglucosan (LG), a marker of woodsmoke, was also measured outdoors. We partitioned PM(2.5) exposure into its ambient-generated (E(ag)) and nonambient (E(na)) components. These exposure metrics were evaluated in relation to daily changes in exhaled nitric oxide (FE(NO)), a marker of airway inflammation, and four lung function measures: midexpiratory flow (MEF), peak expiratory flow (PEF), forced expiratory volume in the first second (FEV(1)), and forced vital capacity (FVC). E(ag), but not E(na), was correlated with combustion markers. Significant associations with respiratory health were seen only among participants not using inhaled corticosteroids. Increases in FE(NO) were associated with personal PM(2.5), personal LAC, and E(ag) but not with ambient PM(2.5) or its combustion markers. In contrast, MEF and PEF decrements were associated with ambient PM(2.5), its combustion markers, and E(ag), but not with personal PM(2.5) or personal LAC. FEV(1) was associated only with ambient LG. Our results suggest that lung function may be especially sensitive to the combustion-generated component of ambient PM(2.5), whereas airway inflammation may be more closely related to some other constituent of the ambient PM(2.5) mixture.
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Affiliation(s)
- Ryan W Allen
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
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Koenig JQ, Mar TF, Allen RW, Jansen K, Lumley T, Sullivan JH, Trenga CA, Larson T, Liu LJS. Pulmonary effects of indoor- and outdoor-generated particles in children with asthma. Environ Health Perspect 2005; 113:499-503. [PMID: 15811822 PMCID: PMC1278493 DOI: 10.1289/ehp.7511] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Accepted: 01/10/2005] [Indexed: 05/03/2023]
Abstract
Most particulate matter (PM) health effects studies use outdoor (ambient) PM as a surrogate for personal exposure. However, people spend most of their time indoors exposed to a combination of indoor-generated particles and ambient particles that have infiltrated. Thus, it is important to investigate the differential health effects of indoor- and ambient-generated particles. We combined our recently adapted recursive model and a predictive model for estimating infiltration efficiency to separate personal exposure (E) to PM2.5 (PM with aerodynamic diameter < or = 2.5 microm) into its indoor-generated (Eig) and ambient-generated (Eag) components for 19 children with asthma. We then compared Eig and Eag to changes in exhaled nitric oxide (eNO), a marker of airway inflammation. Based on the recursive model with a sample size of eight children, Eag was marginally associated with increases in eNO [5.6 ppb per 10-microg/m3 increase in PM2.5; 95% confidence interval (CI), -0.6 to 11.9; p = 0.08]. Eig was not associated with eNO (-0.19 ppb change per 10 microg/m3). Our predictive model allowed us to estimate Eag and Eig for all 19 children. For those combined estimates, only Eag was significantly associated with an increase in eNO (Eag: 5.0 ppb per 10-microg/m3 increase in PM2.5; 95% CI, 0.3 to 9.7; p = 0.04; Eig: 3.3 ppb per 10-microg/m3 increase in PM2.5; 95% CI, -1.1 to 7.7; p = 0.15). Effects were seen only in children who were not using corticosteroid therapy. We conclude that the ambient-generated component of PM2.5 exposure is consistently associated with increases in eNO and the indoor-generated component is less strongly associated with eNO.
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Affiliation(s)
- Jane Q Koenig
- Department of Environmental Health and Occupational Sciences, University of Washington, Seattle, Washington 98195, USA.
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Murnaghan JM, Henderson SA, Allen RW. Burning issue: a danger of epidurals. Anaesthesia 2003; 58:613. [PMID: 12846647 DOI: 10.1046/j.1365-2044.2003.03207_18.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
Experience performing prenatal genotyping for RHD has shown that consideration must be given to developing a molecular test capable of detecting recombination/gene conversion events involving the RHD and RHCE genes that can lead to erroneous results. Out of 50 prenatal RHD tests performed over the past 5 years, four samples were encountered that gave false-positive results. In only one of the tests, incorrect results were issued to the physician. In the other three instances, the erroneous nature of the test results was revealed through the analysis of multiple regions of the RHD gene and, more importantly, because the mother, and sometimes the father, were tested in parallel with the fetus. In an extension of the observations obtained from the prenatal testing program, a large panel of RhD-negative blood donors were subjected to molecular analysis of the RHD gene. Of 1,183 donors screened, 187 were found to phenotype as RhD negative. Of the 187 donors confirmed RhD negative serologically, 22 (11.8%) were found to retain remnants of the RHD gene that, depending upon the characteristics of the molecular assay performed, could lead to a false-positive result in a genotyping assay. On the basis of the experience presented here, it is recommended that any molecular RHD assay include an analysis of multiple areas of the RHD gene so as to allow for the detection of recombination/gene conversion events between the RHD and RHCE genes. Moreover, it is strongly recommended that the mother (at a minimum) and father be subjected to molecular analysis simultaneously with the fetus to confirm that the known phenotypes of the parent(s) are consistent with their respective genotypes.
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Affiliation(s)
- R W Allen
- H.A. Chapman Institute of Medical Genetics, Tulsa, OK 74135, USA.
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