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Qi Q, Yu F, Nair AA, Lau SSS, Luo G, Mithu I, Zhang W, Li S, Lin S. Hidden danger: The long-term effect of ultrafine particles on mortality and its sociodemographic disparities in New York State. JOURNAL OF HAZARDOUS MATERIALS 2024; 471:134317. [PMID: 38636229 DOI: 10.1016/j.jhazmat.2024.134317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 04/09/2024] [Accepted: 04/14/2024] [Indexed: 04/20/2024]
Abstract
Although previous studies have shown increased health risks of particulate matters, few have evaluated the long-term health impacts of ultrafine particles (UFPs or PM0.1, ≤ 0.1 µm in diameter). This study assessed the association between long-term exposure to UFPs and mortality in New York State (NYS), including total non-accidental and cause-specific mortalities, sociodemographic disparities and seasonal trends. Collecting data from a comprehensive chemical transport model and NYS Vital Records, we used the interquartile range (IQR) and high-level UFPs (≥75 % percentile) as indicators to link with mortalities. Our modified difference-in-difference model controlled for other pollutants, meteorological factors, spatial and temporal confounders. The findings indicate that long-term UFPs exposure significantly increases the risk of non-accidental mortality (RR=1.10, 95 % CI: 1.05, 1.17), cardiovascular mortality (RR=1.11, 95 % CI: 1.05, 1.18) particularly for cerebrovascular (RR=1.21, 95 % CI: 1.10, 1.35) and pulmonary heart diseases (RR=1.33, 95 % CI: 1.13, 1.57), and respiratory mortality (borderline significance, RR=1.09, 95 % CI: 1.00, 1.18). Hispanics (RR=1.13, 95 % CI: 1.00, 1.29) and non-Hispanic Blacks (RR=1.40, 95 % CI: 1.16, 1.68) experienced significantly higher mortality risk after exposure to UFPs, compared to non-Hispanic Whites. Children under five, older adults, non-NYC residents, and winter seasons are more susceptible to UFPs' effects.
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Affiliation(s)
- Quan Qi
- Department of Economics, University at Albany, State University of New York, Albany, NY, USA
| | - Fangqun Yu
- Atmospheric Sciences Research Center, University at Albany, State University of New York, Albany, NY, USA
| | - Arshad A Nair
- Atmospheric Sciences Research Center, University at Albany, State University of New York, Albany, NY, USA
| | - Sam S S Lau
- Research Centre for Environment and Human Health & College of International Education, School of Continuing Education, Hong Kong Baptist University, Hong Kong, China; Institute of Bioresource and Agriculture, Hong Kong Baptist University, Hong Kong, China
| | - Gan Luo
- Atmospheric Sciences Research Center, University at Albany, State University of New York, Albany, NY, USA
| | - Imran Mithu
- Community, Environment and Policy Division, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - Wangjian Zhang
- Department of Medical Statistics, School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Sean Li
- Rausser College of Natural Resources, University of California, Berkeley, CA, USA
| | - Shao Lin
- Department of Epidemiology and Biostatistics, School of Public Health, University at Albany, State University of New York, Rensselaer, NY, USA; Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Rensselaer, NY, USA.
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Indoor Exposure to Selected Air Pollutants in the Home Environment: A Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17238972. [PMID: 33276576 PMCID: PMC7729884 DOI: 10.3390/ijerph17238972] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 11/22/2020] [Accepted: 11/27/2020] [Indexed: 11/17/2022]
Abstract
(1) Background: There is increasing awareness that the quality of the indoor environment affects our health and well-being. Indoor air quality (IAQ) in particular has an impact on multiple health outcomes, including respiratory and cardiovascular illness, allergic symptoms, cancers, and premature mortality. (2) Methods: We carried out a global systematic literature review on indoor exposure to selected air pollutants associated with adverse health effects, and related household characteristics, seasonal influences and occupancy patterns. We screened records from six bibliographic databases: ABI/INFORM, Environment Abstracts, Pollution Abstracts, PubMed, ProQuest Biological and Health Professional, and Scopus. (3) Results: Information on indoor exposure levels and determinants, emission sources, and associated health effects was extracted from 141 studies from 29 countries. The most-studied pollutants were particulate matter (PM2.5 and PM10); nitrogen dioxide (NO2); volatile organic compounds (VOCs) including benzene, toluene, xylenes and formaldehyde; and polycyclic aromatic hydrocarbons (PAHs) including naphthalene. Identified indoor PM2.5 sources include smoking, cooking, heating, use of incense, candles, and insecticides, while cleaning, housework, presence of pets and movement of people were the main sources of coarse particles. Outdoor air is a major PM2.5 source in rooms with natural ventilation in roadside households. Major sources of NO2 indoors are unvented gas heaters and cookers. Predictors of indoor NO2 are ventilation, season, and outdoor NO2 levels. VOCs are emitted from a wide range of indoor and outdoor sources, including smoking, solvent use, renovations, and household products. Formaldehyde levels are higher in newer houses and in the presence of new furniture, while PAH levels are higher in smoking households. High indoor particulate matter, NO2 and VOC levels were typically associated with respiratory symptoms, particularly asthma symptoms in children. (4) Conclusions: Household characteristics and occupant activities play a large role in indoor exposure, particularly cigarette smoking for PM2.5, gas appliances for NO2, and household products for VOCs and PAHs. Home location near high-traffic-density roads, redecoration, and small house size contribute to high indoor air pollution. In most studies, air exchange rates are negatively associated with indoor air pollution. These findings can inform interventions aiming to improve IAQ in residential properties in a variety of settings.
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Madureira J, Slezakova K, Costa C, Pereira MC, Teixeira JP. Assessment of indoor air exposure among newborns and their mothers: Levels and sources of PM 10, PM 2.5 and ultrafine particles at 65 home environments. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 264:114746. [PMID: 32417580 DOI: 10.1016/j.envpol.2020.114746] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 04/11/2020] [Accepted: 05/05/2020] [Indexed: 06/11/2023]
Abstract
Significant efforts have been directed towards addressing the adverse health effects of atmospheric particles, emphasizing the relevance of indoor exposure. Homes represent an indoor environment where human spend the majority of their time. Thus, the objective of this work was to concurrently assess different matrix of indoor particles considering both mass (PM10, PM2.5) and number (N20-1000) concentrations in indoor and outdoor air of homes (n = 65). Real-time measurements (PM10, PM2.5, UFP) were conducted simultaneously during 48 h in dwellings situated in Oporto, Portugal. In 75% of homes, indoor PM2.5 (mean = 53 μg m-3) exceeded limit of 25 μg m-3, for PM10 (mean = 57 μg m-3) 41% of homes demonstrated average levels higher than 50 μg m-3, thus indicating potential risks. Indoor PM10 was mostly (82-99%) composed of PM2.5, both PM were highly correlated (|rs|>0.9655), thus suggesting the similar origin. Indoor PM originated from infiltrations of outdoor emissions; ∼70% of homes exhibited indoor to outdoor (I/O) ratio < 1. On the contrary, UFP indoors (mean = 13.3 × 103 # cm-3) were higher than outdoors (mean = 10.0 × 103 # cm-3). Indoor UFP spatially varied as follows: kitchens > living rooms > bedrooms. UFP indoors were poorly correlated (|rs| = 0.456) with outdoor concentrations, I/O ratios showed that indoor UFP predominantly originated from indoor emission sources (combustions). Therefore, in order to reduce exposure to UFP and protect public health, the primary concerns should be focused on controlling emissions from indoor sources.
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Affiliation(s)
- Joana Madureira
- Environmental Health Department, National Institute of Health, Rua Alexandre Herculano 321, 4000-055, Porto, Portugal; EPIUnit-Instituto de Saúde Pública, Universidade Do Porto, Rua Das Taipas 135, 4050-600, Porto, Portugal
| | - Klara Slezakova
- LEPABE, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade Do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal.
| | - Carla Costa
- Environmental Health Department, National Institute of Health, Rua Alexandre Herculano 321, 4000-055, Porto, Portugal; EPIUnit-Instituto de Saúde Pública, Universidade Do Porto, Rua Das Taipas 135, 4050-600, Porto, Portugal
| | - Maria Carmo Pereira
- LEPABE, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade Do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - João Paulo Teixeira
- Environmental Health Department, National Institute of Health, Rua Alexandre Herculano 321, 4000-055, Porto, Portugal; EPIUnit-Instituto de Saúde Pública, Universidade Do Porto, Rua Das Taipas 135, 4050-600, Porto, Portugal
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Brugge D, Simon MC, Hudda N, Zellmer M, Corlin L, Cleland S, Lu EY, Rivera S, Byrne M, Chung M, Durant JL. Lessons from in-home air filtration intervention trials to reduce urban ultrafine particle number concentrations. BUILDING AND ENVIRONMENT 2017; 126:266-275. [PMID: 29398771 PMCID: PMC5791918 DOI: 10.1016/j.buildenv.2017.10.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
BACKGROUND Exposure to airborne ultrafine particle (UFP; <100 nm in aerodynamic diameter) is an emerging public health problem. Nevertheless, the benefit of using high efficiency particulate arrestance (HEPA) filtration to reduce UFP concentrations in homes is not yet clear. METHODS We conducted a randomized crossover study of HEPA filtration without a washout period in 23 homes of low-income Puerto Ricans in Boston and Chelsea, MA (USA). Most participants were female, older adults who were overweight or obese. Particle number concentrations (PNC, a proxy for UFP) were measured indoors and outdoors at each home continuously for six weeks. Homes received both HEPA filtration and sham filtration for three weeks each in random order. RESULTS Median PNC under HEPA filtration was 50-85% lower compared to sham filtration in most homes, but we found no benefit in terms of reduced inflammation; associations between hsCRP, IL-6, or TNFRII in blood samples and indoor PNC were inverse and not statistically significant. CONCLUSIONS Limitations to our study design likely contributed to our findings. Limitations included carry-over effects, a population that may have been relatively unresponsive to UFP, reduction in PNC even during sham filtration that limited differences between HEPA and sham filtration, window opening by participants, and lack of fine-grained (room-specific) participant time-activity information. Our approach was similar to other recent HEPA intervention studies of particulate matter exposure and cardiovascular risk, suggesting that there is a need for better study designs.
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Affiliation(s)
- Doug Brugge
- Department of Public Health and Community Medicine, Tufts University School of Medicine, 136 Harrison Ave., Boston, MA 02111
- Jonathan M. Tisch College of Civic Life, Lincoln Filene Hall, Tufts University, Medford, MA 02155
- Department of Civil and Environmental Engineering, Tufts University School of Engineering, Tufts University, Medford, MA 02155
| | - Matthew C Simon
- Department of Civil and Environmental Engineering, Tufts University School of Engineering, Tufts University, Medford, MA 02155
| | - Neelakshi Hudda
- Department of Civil and Environmental Engineering, Tufts University School of Engineering, Tufts University, Medford, MA 02155
| | - Marisa Zellmer
- Department of Civil and Environmental Engineering, Tufts University School of Engineering, Tufts University, Medford, MA 02155
| | - Laura Corlin
- Department of Civil and Environmental Engineering, Tufts University School of Engineering, Tufts University, Medford, MA 02155
| | | | - Eda Yiqi Lu
- University of Massachusetts Amherst, 360 Campus Center Way, Amherst, MA 01003
| | - Sonja Rivera
- Department of Public Health and Community Medicine, Tufts University School of Medicine, 136 Harrison Ave., Boston, MA 02111
| | - Megan Byrne
- Department of Community Health, Tufts University, Medford, MA 02155
| | - Mei Chung
- Department of Public Health and Community Medicine, Tufts University School of Medicine, 136 Harrison Ave., Boston, MA 02111
| | - John L Durant
- Department of Civil and Environmental Engineering, Tufts University School of Engineering, Tufts University, Medford, MA 02155
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Wells JM, Morrison JB, Bhatt SP, Nath H, Dransfield MT. Pulmonary Artery Enlargement Is Associated With Cardiac Injury During Severe Exacerbations of COPD. Chest 2016; 149:1197-204. [PMID: 26501747 DOI: 10.1378/chest.15-1504] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 08/27/2015] [Accepted: 10/01/2015] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Relative pulmonary arterial enlargement, defined by a pulmonary artery to aorta (PA/A) ratio > 1 on CT scanning, predicts hospitalization for acute exacerbations of COPD (AECOPD). However, it is unclear how AECOPD affect the PA/A ratio. We hypothesized that the PA/A ratio would increase at the time of AECOPD and that a ratio > 1 would be associated with worse clinical outcomes. METHODS Patients discharged with an International Classification of Diseases, Ninth Revision, diagnosis of AECOPD from a single center over a 5-year period were identified. Patients were included who had a CT scan performed during the stable period prior to the index AECOPD episode as well as a CT scan at the time of hospitalization. A subset of patients also underwent postexacerbation CT scans. The pulmonary arterial diameter, ascending aortic diameter, and the PA/A ratio were measured on CT scans. Demographic data, comorbidities, troponin level, and hospital outcome data were analyzed. RESULTS A total of 134 patients were included in the study. They had a mean age of 65 ± 10 years, 47% were male, and 69% were white; overall, patients had a mean FEV1 of 47% ± 19%. The PA/A ratio increased from baseline at the time of exacerbation (0.97 ± 0.15 from 0.91 ± 0.17; P < .001). Younger age and known pulmonary hypertension were independently associated with an exacerbation PA/A ratio > 1. Patients with PA/A ratio > 1 had higher troponin values. Those with a PA/A ratio > 1 and troponin levels > 0.01 ng/mL had increased acute respiratory failure, ICU admission, or inpatient mortality compared with those without both factors (P = .0028). The PA/A ratio returned to baseline values following AECOPD. CONCLUSIONS The PA/A ratio increased at the time of severe AECOPD and a ratio > 1 predicted cardiac injury and a more severe hospital course.
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Affiliation(s)
- J Michael Wells
- Division of Pulmonary, Allergy, and Critical Care, University of Alabama at Birmingham, Birmingham, AL; Department of Medicine, University of Alabama at Birmingham, Birmingham, AL; Lung Health Center, University of Alabama at Birmingham, Birmingham, AL; Birmingham VA Medical Center, Birmingham, AL.
| | - Joshua B Morrison
- Division of Pulmonary, Allergy, and Critical Care, University of Alabama at Birmingham, Birmingham, AL; Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Surya P Bhatt
- Division of Pulmonary, Allergy, and Critical Care, University of Alabama at Birmingham, Birmingham, AL; Department of Medicine, University of Alabama at Birmingham, Birmingham, AL; Lung Health Center, University of Alabama at Birmingham, Birmingham, AL
| | - Hrudaya Nath
- Division of Cardiothoracic Imaging, Department of Radiology, University of Alabama at Birmingham, Birmingham, AL
| | - Mark T Dransfield
- Division of Pulmonary, Allergy, and Critical Care, University of Alabama at Birmingham, Birmingham, AL; Department of Medicine, University of Alabama at Birmingham, Birmingham, AL; Lung Health Center, University of Alabama at Birmingham, Birmingham, AL; Birmingham VA Medical Center, Birmingham, AL
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Gu J, Kraus U, Schneider A, Hampel R, Pitz M, Breitner S, Wolf K, Hänninen O, Peters A, Cyrys J. Personal day-time exposure to ultrafine particles in different microenvironments. Int J Hyg Environ Health 2014; 218:188-95. [PMID: 25458919 DOI: 10.1016/j.ijheh.2014.10.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/08/2014] [Accepted: 10/09/2014] [Indexed: 11/28/2022]
Abstract
In order to assess the personal exposure to ultrafine particles (UFP) during individual day-time activities and to investigate the impact of different microenvironments on exposure, we measured personal exposure to particle number concentrations (PNC), a surrogate for UFP, among 112 non-smoking participants in Augsburg, Germany over a nearly two-year period from March 2007 to December 2008. We obtained 337 personal PNC measurements from 112 participants together with dairies of their activities and locations. The measurements lasted on average 5.5h and contained on average 330 observations. In addition, ambient PNC were measured at an urban background stationary monitoring site. Personal PNC were highly variable between measurements (IQR of mean: 11780-24650cm(-3)) and also within a single measurement. Outdoor personal PNC in traffic environments were about two times higher than in non-traffic environments. Higher indoor personal PNC were associated with activities like cooking, being in a bistro or exposure to passive smoking. Overall, personal and stationary PNC were weakly to moderately correlated (r<0.41). Personal PNC were much higher than stationary PNC in traffic (ratio: 1.5), when shopping (ratio: 2.4), and indoors with water vapor (ratio: 2.5). Additive mixed models were applied to predict personal PNC by participants' activities and locations. Traffic microenvironments were significant determinants for outdoor personal PNC. Being in a bistro, passive smoking, and cooking contributed significantly to an increased indoor personal PNC.
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Affiliation(s)
- Jianwei Gu
- Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; Environment Science Center, University of Augsburg, Universitätsstr. 1a, 86159 Augsburg, Germany.
| | - Ute Kraus
- Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Alexandra Schneider
- Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Regina Hampel
- Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Mike Pitz
- Bavarian Environment Agency, Bürgermeister-Ulrich-Str. 160, 86179 Augsburg, Germany
| | - Susanne Breitner
- Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Kathrin Wolf
- Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Otto Hänninen
- Department of Environmental Health, National Institute for Health and Welfare, PO Box 95, Kuopio, Finland
| | - Annette Peters
- Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Josef Cyrys
- Institute of Epidemiology II, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; Environment Science Center, University of Augsburg, Universitätsstr. 1a, 86159 Augsburg, Germany
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Numerical comparison of airborne particles deposition and dispersion in radiator and floor heating systems. ADV POWDER TECHNOL 2014. [DOI: 10.1016/j.apt.2013.06.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Bhangar S, Mullen NA, Hering SV, Kreisberg NM, Nazaroff WW. Ultrafine particle concentrations and exposures in seven residences in northern California. INDOOR AIR 2011; 21:132-44. [PMID: 21029183 DOI: 10.1111/j.1600-0668.2010.00689.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
UNLABELLED Human exposures to ultrafine particles (UFP) are poorly characterized given the potential associated health risks. Residences are important sites of exposure. To characterize residential exposures to UFP in some circumstances and to investigate governing factors, seven single-family houses in California were studied during 2007-2009. During multiday periods, time-resolved particle number concentrations were monitored indoors and outdoors and information was acquired concerning occupancy, source-related activities, and building operation. On average, occupants were home for 70% of their time. The geometric mean time-average residential exposure concentration for 21 study subjects was 14,500 particles per cm(3) (GSD = 1.8; arithmetic mean ± standard deviation = 17,000 ± 10,300 particles per cm(3)). The average contribution to residential exposures from indoor episodic sources was 150% of the contribution from particles of outdoor origin. Unvented natural-gas pilot lights contributed up to 19% to exposure for the two households where present. Episodic indoor source activities, most notably cooking, caused the highest peak exposures and most of the variation in exposure among houses. Owing to the importance of indoor sources and variations in the infiltration factor, residential exposure to UFP cannot be characterized by ambient measurements alone. PRACTICAL IMPLICATIONS Indoor and outdoor sources each contribute to residential ultrafine particle (UFP) concentrations and exposures. Under the conditions investigated, peak exposure concentrations indoors were associated with cooking, using candles, or the use of a furnace. Active particle removal systems can mitigate exposure by reducing the persistence of particles indoors. Eliminating the use of unvented gas pilot lights on cooking appliances could also be beneficial. The study results indicate that characterization of human exposure to UFP, an air pollutant of emerging public health concern, cannot be accomplished without a good understanding of conditions inside residences.
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Affiliation(s)
- S Bhangar
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720-1710, USA
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Myatt TA, Kaufman MH, Allen JG, MacIntosh DL, Fabian MP, McDevitt JJ. Modeling the airborne survival of influenza virus in a residential setting: the impacts of home humidification. Environ Health 2010; 9:55. [PMID: 20815876 PMCID: PMC2940868 DOI: 10.1186/1476-069x-9-55] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Accepted: 09/03/2010] [Indexed: 05/17/2023]
Abstract
BACKGROUND Laboratory research studies indicate that aerosolized influenza viruses survive for longer periods at low relative humidity (RH) conditions. Further analysis has shown that absolute humidity (AH) may be an improved predictor of virus survival in the environment. Maintaining airborne moisture levels that reduce survival of the virus in the air and on surfaces could be another tool for managing public health risks of influenza. METHODS A multi-zone indoor air quality model was used to evaluate the ability of portable humidifiers to control moisture content of the air and the potential related benefit of decreasing survival of influenza viruses in single-family residences. We modeled indoor AH and influenza virus concentrations during winter months (Northeast US) using the CONTAM multi-zone indoor air quality model. A two-story residential template was used under two different ventilation conditions - forced hot air and radiant heating. Humidity was evaluated on a room-specific and whole house basis. Estimates of emission rates for influenza virus were particle-size specific and derived from published studies and included emissions during both tidal breathing and coughing events. The survival of the influenza virus was determined based on the established relationship between AH and virus survival. RESULTS The presence of a portable humidifier with an output of 0.16 kg water per hour in the bedroom resulted in an increase in median sleeping hours AH/RH levels of 11 to 19% compared to periods without a humidifier present. The associated percent decrease in influenza virus survival was 17.5 - 31.6%. Distribution of water vapor through a residence was estimated to yield 3 to 12% increases in AH/RH and 7.8-13.9% reductions in influenza virus survival. CONCLUSION This modeling analysis demonstrates the potential benefit of portable residential humidifiers in reducing the survival of aerosolized influenza virus by controlling humidity indoors.
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Affiliation(s)
| | | | - Joseph G Allen
- Environmental Health & Engineering, Inc., Needham, MA, USA
| | | | - M Patricia Fabian
- Harvard School of Public Health, Department of Environmental Health, Boston, MA, USA
| | - James J McDevitt
- Harvard School of Public Health, Department of Environmental Health, Boston, MA, USA
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Bernstein JA, Alexis N, Bacchus H, Bernstein IL, Fritz P, Horner E, Li N, Mason S, Nel A, Oullette J, Reijula K, Reponen T, Seltzer J, Smith A, Tarlo SM. The health effects of nonindustrial indoor air pollution. J Allergy Clin Immunol 2008; 121:585-91. [DOI: 10.1016/j.jaci.2007.10.045] [Citation(s) in RCA: 294] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 10/15/2007] [Accepted: 10/19/2007] [Indexed: 10/22/2022]
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Weichenthal S, Dufresne A, Infante-Rivard C, Joseph L. Characterizing and predicting ultrafine particle counts in Canadian classrooms during the winter months: model development and evaluation. ENVIRONMENTAL RESEARCH 2008; 106:349-60. [PMID: 17919560 DOI: 10.1016/j.envres.2007.08.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2007] [Revised: 08/08/2007] [Accepted: 08/22/2007] [Indexed: 05/16/2023]
Abstract
School classrooms are potentially important micro-environments for childhood exposures owing to the large amount of time children spend in these locations. While a number of airborne contaminants may be present in schools, to date few studies have examined ultrafine particle (0.02-1 microm) (UFP) levels in classrooms. In this study, our objective was to characterize UFP counts (cm(-3)) in classrooms during the winter months and to develop a model to predict such exposures based on ambient weather conditions and outdoor UFPs, as well as classroom characteristics such as size, temperature, relative humidity, and carbon dioxide levels. In total, UFP count data were collected on 60 occasions in 37 occupied classrooms at one elementary school and one secondary school in Pembroke, Ontario. On average, outdoor UFP levels exceeded indoor measures by 8989 cm(-3) (95% confidence interval (CI): 6382, 11596), and classroom UFP counts were similar at both schools with a combined average of 5017 cm(-3) (95% CI: 4300, 5734). Of the variables examined only wind speed and outdoor UFPs were important determinants of classrooms UFP levels. Specifically, each 10 km/h increase in wind speed corresponded to an 1873 cm(-3) (95% CI: 825, 2920) decrease in classroom UFP counts, and each 10000 cm(-3) increase in outdoor UFPs corresponded to a 1550 cm(-3) (95% CI: 930, 2171) increase in classroom UFP levels. However, high correlations between these two predictors meant that the independent effects of wind speed and outdoor UFPs could not be separated in multivariable models, and only outdoor UFP counts were included in the final predictive model. To evaluate model performance, classroom UFP counts were collected for 8 days at two new schools and compared to predicted values based on outdoor UFP measures. A moderate correlation was observed between measured and predicted classroom UFP counts (r=0.63) for both schools combined, but this relationship was not valid on days in which a strong indoor UFP source (electric kitchen stove) was active in schools. In general, our findings suggest that reasonable estimates of classroom UFP counts may be obtained from outdoor UFP data but that the accuracy of such estimates are limited in the presence of indoor UFP sources.
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Affiliation(s)
- Scott Weichenthal
- Department of Epidemiology, Biostatistics and Occupational Health, Faculty of Medicine, McGill University, 1130 Pine Avenue West, Montréal, Québec, Canada.
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