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Rasmussen PE, Levesque C, Butler O, Chénier M, Gardner HD. Selection of metric for indoor-outdoor source apportionment of metals in PM 2.5 : mg/kg versus ng/m 3. INDOOR AIR 2022; 32:e12924. [PMID: 34418165 PMCID: PMC9292266 DOI: 10.1111/ina.12924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/05/2021] [Accepted: 08/06/2021] [Indexed: 06/13/2023]
Abstract
Trends in the elemental composition of fine particulate matter (PM2.5 ) collected from indoor, outdoor, and personal microenvironments were investigated using two metrics: ng/m3 and mg/kg. Pearson correlations that were positive using one metric commonly disappeared or flipped to become negative when the other metric was applied to the same dataset. For example, the correlation between Mo and S in the outdoor microenvironment was positive using ng/m3 (p < 0.05) but negative using mg/kg (p < 0.05). In general, elemental concentrations (mg/kg) within PM2.5 decreased significantly (p < 0.05) as PM2.5 concentrations (µg/m3 ) increased-a dilution effect that was observed in all microenvironments and seasons. An exception was S: in the outdoor microenvironment, the correlation between wt% S and PM2.5 flipped from negative in the winter (p < 0.01) to positive (p < 0.01) in the summer, whereas in the indoor microenvironment, this correlation was negative year-round (p < 0.05). Correlation analyses using mg/kg indicated that elemental associations may arise from Fe-Mn oxyhydroxide sorption processes that occur as particles age, with or without the presence of a common anthropogenic source. Application of mass-normalized concentration metrics (mg/kg or wt%), enabled by careful gravimetric analysis, revealed new evidence of the importance of indoor sources of elements in PM2.5 .
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Affiliation(s)
- Pat E. Rasmussen
- Environmental Health Science and Research BureauHealthy Environments and Consumer Safety BranchHealth CanadaOttawaONCanada
- Department of Earth and Environmental SciencesUniversity of OttawaOttawaONCanada
| | - Christine Levesque
- Environmental Health Science and Research BureauHealthy Environments and Consumer Safety BranchHealth CanadaOttawaONCanada
| | | | - Marc Chénier
- Environmental Health Science and Research BureauHealthy Environments and Consumer Safety BranchHealth CanadaOttawaONCanada
| | - H. David Gardner
- Environmental Health Science and Research BureauHealthy Environments and Consumer Safety BranchHealth CanadaOttawaONCanada
- Department of Earth and Environmental SciencesUniversity of OttawaOttawaONCanada
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Janjua S, Powell P, Atkinson R, Stovold E, Fortescue R. Individual-level interventions to reduce personal exposure to outdoor air pollution and their effects on people with long-term respiratory conditions. Cochrane Database Syst Rev 2021; 8:CD013441. [PMID: 34368949 PMCID: PMC8407478 DOI: 10.1002/14651858.cd013441.pub2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND More than 90% of the global population lives in areas exceeding World Health Organization air quality limits. More than four million people each year are thought to die early due to air pollution, and poor air quality is thought to reduce an average European's life expectancy by one year. Individuals may be able to reduce health risks through interventions such as masks, behavioural changes and use of air quality alerts. To date, evidence is lacking about the efficacy and safety of such interventions for the general population and people with long-term respiratory conditions. This topic, and the review question relating to supporting evidence to avoid or lessen the effects of air pollution, emerged directly from a group of people with chronic obstructive pulmonary disease (COPD) in South London, UK. OBJECTIVES 1. To assess the efficacy, safety and acceptability of individual-level interventions that aim to help people with or without chronic respiratory conditions to reduce their exposure to outdoor air pollution. 2. To assess the efficacy, safety and acceptability of individual-level interventions that aim to help people with chronic respiratory conditions reduce the personal impact of outdoor air pollution and improve health outcomes. SEARCH METHODS We identified studies from the Cochrane Airways Trials Register, Cochrane Central Register of Controlled Trials, and other major databases. We did not restrict our searches by date, language or publication type and included a search of the grey literature (e.g. unpublished information). We conducted the most recent search on 16 October 2020. SELECTION CRITERIA We included randomised controlled trials (RCTs) and non-randomised studies (NRS) that included a comparison treatment arm, in adults and children that investigated the effectiveness of an individual-level intervention to reduce risks of outdoor air pollution. We included studies in healthy individuals and those in people with long-term respiratory conditions. We excluded studies which focused on non-respiratory long-term conditions, such as cardiovascular disease. We did not restrict eligibility of studies based on outcomes. DATA COLLECTION AND ANALYSIS We used standard Cochrane methods. Two review authors independently selected trials for inclusion, extracted study characteristics and outcome data, and assessed risk of bias using the Cochrane Risk of Bias tool for RCTs and the Risk Of Bias In Non-randomised Studies - of Interventions (ROBINS-I) as appropriate. One review author entered data into the review; this was spot-checked by a second author. We planned to meta-analyse results from RCTs and NRS separately, using a random-effects model. This was not possible, so we presented evidence narratively. We assessed certainty of the evidence using the GRADE approach. Primary outcomes were: measures of air pollution exposure; exacerbation of respiratory conditions; hospital admissions; quality of life; and serious adverse events. MAIN RESULTS We identified 11 studies (3372 participants) meeting our inclusion criteria (10 RCTs and one NRS). Participants' ages ranged from 18 to 74 years, and the duration of studies ranged from 24 hours to 104 weeks. Six cross-over studies recruited healthy adults and five parallel studies included either people with pre-existing conditions (three studies) or only pregnant women (two studies). Interventions included masks (e.g. an N95 mask designed to filter out airborne particles) (five studies), an alternative cycle route (one study), air quality alerts and education (five studies). Studies were set in Australia, China, Iran, the UK, and the USA. Due to the diversity of study designs, populations, interventions and outcomes, we did not perform any meta-analyses and instead summarised results narratively. We judged both RCTs and the NRS to be at risk of bias from lack of blinding and lack of clarity regarding selection methods. Many studies did not provide a prepublished protocol or trial registration. From five studies (184 participants), we found that masks or altered cycle routes may have little or no impact on physiological markers of air pollution exposure (e.g. blood pressure and heart rate variability), but we are very uncertain about this estimate using the GRADE approach. We found conflicting evidence regarding health care usage from three studies of air pollution alerts, with one non-randomised cross-over trial (35 participants) reporting an increase in emergency hospital attendances and admissions, but the other two randomised parallel trials (1553 participants) reporting little to no difference. We also gave the evidence for this outcome a very uncertain GRADE rating. None of our included trials reported respiratory exacerbations, quality of life or serious adverse events. Secondary outcomes were not well reported, but indicated inconsistent impacts of air quality alerts and education interventions on adherence, with some trials reporting improvements in the intervention groups and others reporting little or no difference. Symptoms were reported by three trials, with one randomised cross-over trial (15 participants) reporting a small increase in breathing difficulties associated with the mask intervention, one non-randomised cross-over trial (35 participants) reporting reduced throat and nasal irritation in the lower-pollution cycle route group (but no clear difference in other respiratory symptoms), and another randomised parallel trial (519 participants) reporting no clear difference in symptoms between those who received a smog warning and those who did not. AUTHORS' CONCLUSIONS The lack of evidence and study diversity has limited the conclusions of this review. Using a mask or a lower-pollution cycle route may mitigate some of the physiological impacts from air pollution, but evidence was very uncertain. We found conflicting results for other outcomes, including health care usage, symptoms and adherence/behaviour change. We did not find evidence for adverse events. Funders should consider commissioning larger, longer studies, using high-quality and well-described methods, recruiting participants with pre-existing respiratory conditions. Studies should report outcomes of importance to people with respiratory conditions, such as exacerbations, hospital admissions, quality of life and adverse events.
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Affiliation(s)
- Sadia Janjua
- Cochrane Airways, Population Health Research Institute, St George's, University of London, London, UK
| | | | - Richard Atkinson
- Population Health Research Institute, St George's, University of London, London, UK
| | - Elizabeth Stovold
- Cochrane Airways, Population Health Research Institute, St George's, University of London, London, UK
| | - Rebecca Fortescue
- Cochrane Airways, Population Health Research Institute, St George's, University of London, London, UK
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Van Ryswyk K, Evans GJ, Kulka R, Sun L, Sabaliauskas K, Rouleau M, Anastasopolos AT, Wallace L, Weichenthal S. Personal exposures to traffic-related air pollution in three Canadian bus transit systems: the Urban Transportation Exposure Study. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2021; 31:628-640. [PMID: 32678304 PMCID: PMC8263338 DOI: 10.1038/s41370-020-0242-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 05/20/2020] [Accepted: 06/05/2020] [Indexed: 05/06/2023]
Abstract
BACKGROUND Exposure to traffic-related air pollution (TRAP) is associated with increased incidence of several cardiopulmonary diseases. The elevated TRAP exposures of commuting environments can result in significant contributions to daily exposures. OBJECTIVES To assess the personal TRAP exposures (UFPs, BC, PM2.5, and PM10) of the bus transit systems of Toronto, Ottawa, and Vancouver, Canada. Personal exposure models estimated the contribution of bus commuting to daily TRAP exposures. Associations between bus type and riding exposures and bus stop/station type and waiting exposures were estimated. RESULTS Bus commuting (4.6% of the day) contributed ~59%(SD = 15%), 60%(SD = 20%), and 57%(SD = 18%) of daily PM2.5-Ba and 70%(SD = 19%), 64%(SD = 15%), and 70%(SD = 15%) of daily PM2.5-Fe, in Toronto, Ottawa, and Vancouver, respectively. Enclosed bus stations were found to be hotspots of PM2.5 and BC. Buses with diesel particulate filters (DPFs) and hybrid diesel/electric propulsion were found to have significantly lower in-bus PM2.5, UFP, and BC relative to 1983-2003 diesel buses in each city with the exception of UFP in Vancouver. SIGNIFICANCE Personal exposures for traffic-related air pollutants were assessed for three Canadian bus transit systems. In each system, bus commuting was estimated to contribute significantly toward daily exposures of fine-fraction Ba and Fe as well as BC. Exposures while riding were associated with bus type for several pollutants in each city. These associations suggest the use of hybrid diesel/electric buses equipped with diesel particulate filters have improved air quality for riders.
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Affiliation(s)
- Keith Van Ryswyk
- Air Health Science Division, Health Canada, Ottawa, ON, K1A 0K9, Canada.
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada.
| | - Greg J Evans
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Ryan Kulka
- Air Health Science Division, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Liu Sun
- Air Health Science Division, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Kelly Sabaliauskas
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Mathieu Rouleau
- Air Health Science Division, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | | | | | - Scott Weichenthal
- Air Health Science Division, Health Canada, Ottawa, ON, K1A 0K9, Canada
- Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, QC, H3A 1A2, Canada
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Sultan ZM, Pantelic J, Tham KW. Infiltration of fine particles in urban daycares. INDOOR AIR 2020; 30:955-965. [PMID: 32304116 DOI: 10.1111/ina.12679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 03/16/2020] [Accepted: 04/08/2020] [Indexed: 06/11/2023]
Abstract
Singapore is a tropical country with a high density of day-care facilities whose indoor environments may be adversely affected by outdoor fine particle (PM2.5 ) air pollution. To reduce this problem requires effective, evidence-based exposure-reduction strategies. Little information is available on the penetration of outdoor PM2.5 into day-care environments. Our study attempted to address the following objectives: to measure indoor infiltration factor (Finf ) of PM2.5 from outdoor PM2.5 and to determine the building parameters that modify the indoor PM2.5 . We collected indoor/outdoor 1-min PM2.5 from 50 day-care classrooms. We noted mean Finf ± SD of 0.65 ± 0.22 in day-care rooms which are naturally ventilated and lower Finf ± SD values of 0.47 ± 0.18 for those that are air-conditioned: values which are lower than those reported in Singapore residences. The air exchange rates were higher in naturally ventilated rooms (1.47 vs 0.86 h-1 ). However, fine particle deposition rates were lower for naturally ventilated rooms (0.67 ± 0.43 h-1 ) compared with air-conditioned ones (1.03 ± 0.55 h-1 ) presumably due to composite rates linked to the filters within the split unit air-conditioners, higher recirculation rates, and interior surfaces in the latter. Our findings indicate that children remaining indoor in daycares where air-conditioning is used can reduce their PM2.5 exposures during outdoor pollution episodes.
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Affiliation(s)
- Zuraimi M Sultan
- Berkeley Education Alliance for Research in Singapore (BEARS) Limited, Singapore, Singapore
| | - Jovan Pantelic
- Center for the Built Environment, University of California Berkeley, Berkeley, CA, USA
| | - Kwok Wai Tham
- Department of Building, National University of Singapore, Singapore, Singapore
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Ha S, Nobles C, Kanner J, Sherman S, Cho SH, Perkins N, Williams A, Grobman W, Biggio J, Subramaniam A, Ouidir M, Chen Z, Mendola P. Air Pollution Exposure Monitoring among Pregnant Women with and without Asthma. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17134888. [PMID: 32645870 PMCID: PMC7369909 DOI: 10.3390/ijerph17134888] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/18/2020] [Accepted: 06/30/2020] [Indexed: 11/16/2022]
Abstract
Background: We monitored exposure to fine particulates (PM2.5), ozone, nitrogen dioxide (NO2), and ambient temperature for pregnant women with and without asthma. Methods: Women (n = 40) from the Breathe—Well-Being, Environment, Lifestyle, and Lung Function Study (2015–2018) were enrolled during pregnancy and monitored for 2–4 days. Daily pollutants were measured using personal air monitors, indoor air monitors, and nearest Environmental Protection Agency’s stationary monitors based on GPS tracking and home address. Results: Personal-monitor measurements of PM2.5, ozone, and NO2 did not vary by asthma status but exposure profiles significantly differed by assessment methods. EPA stationary monitor-based methods appeared to underestimate PM2.5 and temperature exposure and overestimate ozone and NO2 exposure. Higher indoor-monitored PM2.5 exposures were associated with smoking and the use of gas appliances. The proportion of waking-time during which personal monitors were worn was ~56%. Lower compliance was associated with exercise, smoking, being around a smoker, and the use of a prescription drug. Conclusions: Exposure did not vary by asthma status but was influenced by daily activities and assessment methods. Personal monitors may better capture exposures but non-compliance merits attention. Meanwhile, larger monitoring studies are warranted to further understand exposure profiles and the health effects of air pollution during pregnancy.
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Affiliation(s)
- Sandie Ha
- Department of Public Health, Health Sciences Research Institute, College of Social Sciences, Humanities, and Arts, University of California, Merced, CA 95343, USA
- Correspondence: ; Tel.: +1-209-228-3615
| | - Carrie Nobles
- Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA; (C.N.); (J.K.); (N.P.); (M.O.); (Z.C.); (P.M.)
| | - Jenna Kanner
- Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA; (C.N.); (J.K.); (N.P.); (M.O.); (Z.C.); (P.M.)
| | | | - Seung-Hyun Cho
- RTI International, Research Triangle Park, NC 27709, USA;
| | - Neil Perkins
- Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA; (C.N.); (J.K.); (N.P.); (M.O.); (Z.C.); (P.M.)
| | - Andrew Williams
- School of Medicine & Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA;
| | - William Grobman
- Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA;
| | | | - Akila Subramaniam
- Department of Obstetrics & Gynecology, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - Marion Ouidir
- Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA; (C.N.); (J.K.); (N.P.); (M.O.); (Z.C.); (P.M.)
| | - Zhen Chen
- Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA; (C.N.); (J.K.); (N.P.); (M.O.); (Z.C.); (P.M.)
| | - Pauline Mendola
- Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA; (C.N.); (J.K.); (N.P.); (M.O.); (Z.C.); (P.M.)
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Abstract
Exposure to fine particulate matter (PM) results in adverse health outcomes. Although this is a global concern, residents of China may be particularly vulnerable due to frequent severe air pollution episodes associated with economic growth, industrialization, and urbanization. Until 2012, PM2.5 was not regulated and monitored in China and annual average concentrations far exceeded the World Health Organizations guidelines of 10 μg/m3. Since the establishment of PM2.5 Ambient Air Quality Criteria in 2012, concentrations have decreased, but still pose significant health risks. A review of ambient PM2.5 health effect studies is warranted to evaluate the current state of knowledge and to prioritize future research efforts. Our review found that recent literature has confirmed associations between PM2.5 exposure and total mortality, cardiovascular mortality, respiratory mortality, hypertension, lung cancer, influenza and other adverse health outcomes. Future studies should take a long-term approach to verify associations between exposure to PM2.5 and health effects. In order to obtain adequate exposure assessment at finer spatial resolutions, high density sampling, satellite remote sensing, or models should be employed. Personal monitoring should also be conducted to validate the use of outdoor concentrations as proxies for exposure. More research efforts should be devoted to seasonal patterns, sub-population susceptibility, and the mechanism by which exposure causes health effects. Submicron and ultrafine PM should also be monitored and regulated.
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Van Ryswyk K, Anastasopolos AT, Evans G, Sun L, Sabaliauskas K, Kulka R, Wallace L, Weichenthal S. Metro Commuter Exposures to Particulate Air Pollution and PM 2.5-Associated Elements in Three Canadian Cities: The Urban Transportation Exposure Study. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:5713-5720. [PMID: 28440082 DOI: 10.1021/acs.est.6b05775] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
System-representative commuter air pollution exposure data were collected for the metro systems of Toronto, Montreal, and Vancouver, Canada. Pollutants measured included PM2.5 (PM = particulate matter), PM10, ultrafine particles, black carbon, and the elemental composition of PM2.5. Sampling over three weeks was conducted in summer and winter for each city and covered each system on a daily basis. Mixed-effect linear regression models were used to identify system features related to particulate exposures. Ambient levels of PM2.5 and its elemental components were compared to those of the metro in each city. A microenvironmental exposure model was used to estimate the contribution of a 70 min metro commute to daily mean exposure to PM2.5 elemental and mass concentrations. Time spent in the metro was estimated to contribute the majority of daily exposure to several metallic elements of PM2.5 and 21.2%, 11.3% and 11.5% of daily PM2.5 exposure in Toronto, Montreal, and Vancouver, respectively. Findings suggest that particle air pollutant levels in Canadian metros are substantially impacted by the systems themselves, are highly enriched in steel-based elements, and can contribute a large portion of PM2.5 and its elemental components to a metro commuter's daily exposure.
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Affiliation(s)
- Keith Van Ryswyk
- Air Health Science Division, Health Canada , Ottawa, K1A 0K9, Canada
| | | | - Greg Evans
- Department of Chemical Engineering and Applied Chemistry, University of Toronto , Toronto, M5S 3E5, Canada
| | - Liu Sun
- Air Health Science Division, Health Canada , Ottawa, K1A 0K9, Canada
| | - Kelly Sabaliauskas
- Department of Chemical Engineering and Applied Chemistry, University of Toronto , Toronto, M5S 3E5, Canada
| | - Ryan Kulka
- Air Health Science Division, Health Canada , Ottawa, K1A 0K9, Canada
| | - Lance Wallace
- Consultant, Santa Rosa, California 95409, United States
| | - Scott Weichenthal
- Air Health Science Division, Health Canada , Ottawa, K1A 0K9, Canada
- Department of Epidemiology, Biostatistics, and Occupational Health, McGill University , Montreal, H3A 1A2, Canada
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Sloan CD, Philipp TJ, Bradshaw RK, Chronister S, Barber WB, Johnston JD. Applications of GPS-tracked personal and fixed-location PM(2.5) continuous exposure monitoring. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2016; 66:53-65. [PMID: 26512925 DOI: 10.1080/10962247.2015.1108942] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
UNLABELLED Continued development of personal air pollution monitors is rapidly improving government and research capabilities for data collection. In this study, we tested the feasibility of using GPS-enabled personal exposure monitors to collect personal exposure readings and short-term daily PM2.5 measures at 15 fixed locations throughout a community. The goals were to determine the accuracy of fixed-location monitoring for approximating individual exposures compared to a centralized outdoor air pollution monitor, and to test the utility of two different personal monitors, the RTI MicroPEM V3.2 and TSI SidePak AM510. For personal samples, 24-hr mean PM2.5 concentrations were 6.93 μg/m³ (stderr = 0.15) and 8.47 μg/m³ (stderr = 0.10) for the MicroPEM and SidePak, respectively. Based on time-activity patterns from participant journals, exposures were highest while participants were outdoors (MicroPEM = 7.61 µg/m³, stderr = 1.08, SidePak = 11.85 µg/m³, stderr = 0.83) or in restaurants (MicroPEM = 7.48 µg/m³, stderr = 0.39, SidePak = 24.93 µg/m³, stderr = 0.82), and lowest when participants were exercising indoors (MicroPEM = 4.78 µg/m³, stderr = 0.23, SidePak = 5.63 µg/m³, stderr = 0.08). Mean PM(2.5) at the 15 fixed locations, as measured by the SidePak, ranged from 4.71 µg/m³ (stderr = 0.23) to 12.38 µg/m³ (stderr = 0.45). By comparison, mean 24-h PM(2.5) measured at the centralized outdoor monitor ranged from 2.7 to 6.7 µg/m³ during the study period. The range of average PM(2.5) exposure levels estimated for each participant using the interpolated fixed-location data was 2.83 to 19.26 µg/m³ (mean = 8.3, stderr = 1.4). These estimated levels were compared with average exposure from personal samples. The fixed-location monitoring strategy was useful in identifying high air pollution microclimates throughout the county. For 7 of 10 subjects, the fixed-location monitoring strategy more closely approximated individuals' 24-hr breathing zone exposures than did the centralized outdoor monitor. Highlights are: Individual PM(2.5) exposure levels vary extensively by activity, location and time of day; fixed-location sampling more closely approximated individual exposures than a centralized outdoor monitor; and small, personal exposure monitors provide added utility for individuals, researchers, and public health professionals seeking to more accurately identify air pollution microclimates. IMPLICATIONS Personal air pollution monitoring technology is advancing rapidly. Currently, personal monitors are primarily used in research settings, but could they also support government networks of centralized outdoor monitors? In this study, we found differences in performance and practicality for two personal monitors in different monitoring scenarios. We also found that personal monitors used to collect outdoor area samples were effective at finding pollution microclimates, and more closely approximated actual individual exposure than a central monitor. Though more research is needed, there is strong potential that personal exposure monitors can improve existing monitoring networks.
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Affiliation(s)
- Chantel D Sloan
- a Department of Health Science , Brigham Young University , Provo , Utah , USA
| | - Tyler J Philipp
- a Department of Health Science , Brigham Young University , Provo , Utah , USA
| | - Rebecca K Bradshaw
- a Department of Health Science , Brigham Young University , Provo , Utah , USA
| | - Sara Chronister
- a Department of Health Science , Brigham Young University , Provo , Utah , USA
| | - W Bradford Barber
- a Department of Health Science , Brigham Young University , Provo , Utah , USA
| | - James D Johnston
- a Department of Health Science , Brigham Young University , Provo , Utah , USA
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Van Ryswyk K, Wallace L, Fugler D, MacNeill M, Héroux MÈ, Gibson MD, Guernsey JR, Kindzierski W, Wheeler AJ. Estimation of bias with the single-zone assumption in measurement of residential air exchange using the perfluorocarbon tracer gas method. INDOOR AIR 2015; 25:610-9. [PMID: 25399878 PMCID: PMC4674977 DOI: 10.1111/ina.12171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 11/10/2014] [Indexed: 05/22/2023]
Abstract
UNLABELLED Residential air exchange rates (AERs) are vital in understanding the temporal and spatial drivers of indoor air quality (IAQ). Several methods to quantify AERs have been used in IAQ research, often with the assumption that the home is a single, well-mixed air zone. Since 2005, Health Canada has conducted IAQ studies across Canada in which AERs were measured using the perfluorocarbon tracer (PFT) gas method. Emitters and detectors of a single PFT gas were placed on the main floor to estimate a single-zone AER (AER(1z)). In three of these studies, a second set of emitters and detectors were deployed in the basement or second floor in approximately 10% of homes for a two-zone AER estimate (AER(2z)). In total, 287 daily pairs of AER(2z) and AER(1z) estimates were made from 35 homes across three cities. In 87% of the cases, AER(2z) was higher than AER(1z). Overall, the AER(1z) estimates underestimated AER(2z) by approximately 16% (IQR: 5-32%). This underestimate occurred in all cities and seasons and varied in magnitude seasonally, between homes, and daily, indicating that when measuring residential air exchange using a single PFT gas, the assumption of a single well-mixed air zone very likely results in an under prediction of the AER. PRACTICAL IMPLICATIONS The results of this study suggest that the long-standing assumption that a home represents a single well-mixed air zone may result in a substantial negative bias in air exchange estimates. Indoor air quality professionals should take this finding into consideration when developing study designs or making decisions related to the recommendation and installation of residential ventilation systems.
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Affiliation(s)
- K Van Ryswyk
- Air Health Science Division, Health Canada, Ottawa, ON, Canada
| | | | | | - M MacNeill
- Air Health Science Division, Health Canada, Ottawa, ON, Canada
| | - M È Héroux
- Air Health Science Division, Health Canada, Ottawa, ON, Canada
- Present address: World Health Organization, European Centre for Environment and Health, Bonn, Germany
| | - M D Gibson
- Department of Process Engineering and Applied Science, Dalhousie University, Halifax, NS, Canada
| | - J R Guernsey
- Community Health and Epidemiology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - W Kindzierski
- School of Public Health, University of Alberta, Edmonton, AB, Canada
| | - A J Wheeler
- Air Health Science Division, Health Canada, Ottawa, ON, Canada
- School of Natural Sciences, Edith Cowan University, Joondalup, WA, Australia
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Goldberg MS, Wheeler AJ, Burnett RT, Mayo NE, Valois MF, Brophy JM, Giannetti N. Physiological and perceived health effects from daily changes in air pollution and weather among persons with heart failure: a panel study. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2015; 25:187-199. [PMID: 24938511 DOI: 10.1038/jes.2014.43] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 04/16/2014] [Indexed: 06/03/2023]
Abstract
We carried out this daily diary panel study in Montreal, Quebec, to determine whether oxygen saturation, pulse rate, blood pressure, self-rated health, and shortness of breath at night were associated with concentrations of indoor carbon monoxide (CO), and indoor and outdoor fine particles (PM2.5), temperature, and relative humidity. Over a 2-month consecutive period between 2008 and 2010, we measured daily indoor and outdoor levels of the air pollutants and weather variables and 55 subjects measured their daily health and other variables. To estimate the associations between the health outcomes and the environmental exposures, we used a mixed effects regression model using an autoregressive model of order-one and we adjusted for month and day and personal variables. The general pattern of associations can be summarized as follows: oxygen saturation was reduced for increases in indoor- and outdoor-PM2.5 and temperature. Pulse rate increased on the concurrent day for increases in indoor CO and PM2.5. Diastolic blood pressure increased with increasing indoor and outdoor PM2.5 and relative humidity. Systolic blood pressure increased with indoor PM2.5 and decreased with increasing indoor and outdoor temperature. Self-rated health diminished with increases in outdoor PM2.5 and indoor and outdoor temperature. Self-reported shortness of breath at night increased with increasing indoor and outdoor temperatures. Health in heart failure is affected in the short term by personal and environmental conditions that are manifest in intermediate physiological parameters.
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Affiliation(s)
- Mark S Goldberg
- 1] Department of Medicine, McGill University, Montreal, Quebec, Canada [2] Division of Clinical Epidemiology, Department of Medicine, Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Amanda J Wheeler
- 1] Centre for Ecosystem Management, School of Natural Sciences, Edith Cowan University, Perth, Western Australia, Australia [2] Air Health Science Division, Health Canada, Ottawa, Ontario, Canada
| | - Richard T Burnett
- Biostatistics and Epidemiology Division, Safe Environments Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
| | - Nancy E Mayo
- 1] Department of Medicine, McGill University, Montreal, Quebec, Canada [2] Division of Clinical Epidemiology, Department of Medicine, Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Marie-France Valois
- 1] Department of Medicine, McGill University, Montreal, Quebec, Canada [2] Division of Clinical Epidemiology, Department of Medicine, Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - James M Brophy
- 1] Department of Medicine, McGill University, Montreal, Quebec, Canada [2] Division of Clinical Epidemiology, Department of Medicine, Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Nadia Giannetti
- Department of Medicine, McGill University, Montreal, Quebec, Canada
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Weichenthal S, Van Ryswyk K, Kulka R, Sun L, Wallace L, Joseph L. In-vehicle exposures to particulate air pollution in Canadian metropolitan areas: the urban transportation exposure study. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:597-605. [PMID: 25469563 DOI: 10.1021/es504043a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Commuters may be exposed to increased levels of traffic-related air pollution owing to close proximity to traffic-emissions. We collected in-vehicle and roof-top air pollution measurements over 238 commutes in Montreal, Toronto, and Vancouver, Canada between 2010 and 2013. Voice recordings were used to collect real-time information on traffic density and the presence of diesel vehicles and multivariable linear regression models were used to estimate the impact of these factors on in-vehicle pollutant concentrations (and indoor/outdoor ratios) along with parameters for road type, land use, and meteorology. In-vehicle PM2.5 and NO2 concentrations consistently exceeded regional outdoor levels and each unit increase in the rate of encountering diesel vehicles (count/min) was associated with substantial increases (>100%) in in-vehicle concentrations of ultrafine particles (UFPs), black carbon, and PM2.5 as well as strong increases (>15%) in indoor/outdoor ratios. A model based on meteorology and the length of highway roads within a 500 m buffer explained 53% of the variation in in-vehicle UFPs; however, models for PM2.5 (R(2) = 0.24) and black carbon (R(2) = 0.30) did not perform as well. Our findings suggest that vehicle commuters experience increased exposure to air pollutants and that traffic characteristics, land use, road types, and meteorology are important determinants of these exposures.
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Affiliation(s)
- Scott Weichenthal
- Air Health Science Division, Health Canada, Ottawa, Ontario K1A 0K9, Canada
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Jiao W, Frey HC, Cao Y. Assessment of inter-individual, geographic, and seasonal variability in estimated human exposure to fine particles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:12519-26. [PMID: 23095102 PMCID: PMC3658126 DOI: 10.1021/es302803g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Health effects associated with ambient fine particle (PM(2.5)) exposure are typically estimated based on concentration-response (C-R) functions using area-wide concentration as an exposure surrogate. Persons 65 and older are particularly susceptible to adverse effects from PM(2.5) exposure. Using a stochastic microenvironmental simulation model, distributions of daily PM(2.5) exposures were estimated based on ambient concentration, air exchange rate, penetration factor, deposition rate, indoor emission sources, census data, and activity diary data, and compared for selected regions and seasons. Even though the selected subpopulation spends an average of over 20 h per day indoors, the ratio of daily average estimated exposure to ambient concentration (E(a)/C) is approximately 0.5. The daily average E(a)/C ratio varies by a factor of 4-5 over a 95% frequency range among individuals, primarily from variability in air exchange rates. The mean E(a)/C varies by 6-36% among selected NC, TX, and NYC domains, and 15-34% among four seasons, as a result of regional differences in housing stock and seasonal differences in air exchange rates. Variability in E(a)/C is a key factor that may help explain heterogeneity in C-R functions across cities and seasons. Priorities for improving exposure estimates are discussed.
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Affiliation(s)
- Wan Jiao
- Department of Civil, Construction and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC 27695-7908
| | - H. Christopher Frey
- Department of Civil, Construction and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC 27695-7908
| | - Ye Cao
- Department of Civil, Construction and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC 27695-7908
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