In highly polluted urban areas, personal exposure to PM2.5 and O3 occur daily in various microenvironments. Identifying which microenvironments contribute most to exposure can pinpoint effective exposure reduction strategies and mitigate adverse health impacts.
This work uses real-time sensors to assess the exposures of children with asthma (N = 39) in Shanghai, quantifying microenvironmental exposure to PM2.5 and O3. An air cleaner was deployed in participants’ bedrooms where we hypothesized exposure could be most efficiently reduced. Monitoring occurred for two 48-h periods: one with bedroom filtration (portable air cleaner with HEPA and activated carbon filters) and the other without.
Children spent 91% of their time indoors with the majority spent in their bedroom (47%). Without filtration, the bedroom and classroom environments were the largest contributors to PM2.5 exposure. With filtration, bedroom PM2.5 exposure was reduced by 75% (45% of total exposure). Although filtration status did not impact O3, the largest contribution of O3 exposure also came from the bedroom.
Actions taken to reduce bedroom PM2.5 and O3 concentrations can most efficiently reduce total exposure. As real-time pollutant monitors become more accessible, similar analyses can be used to evaluate new interventions and optimize exposure reductions for a variety of populations.
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Cohen AJ, Brauer M, Burnett R, Anderson HR, Frostad J, Estep K, et al. Estimates and 25-year trends of the global burden of disease attributable to ambient air pollution: an analysis of data from the Global Burden of Diseases Study 2015. Lancet. 2017;389:1907–18.
WHO. WHO global urban ambient air pollution database. 2016;
Guarnieri M, Balmes JR. Outdoor air pollution and asthma. Lancet. 2014;383:1581–92. https://linkinghub.elsevier.com/retrieve/pii/S0140673614606176.
Shannon MW, Best D, Binns HJ, Johnson CL, Kim JJ, Mazur LJ, et al. Ambient air pollution: health hazards to children. Pediatrics. 2004;114:1699–707.
Morishita M, Thompson KC, Brook RD. Understanding air pollution and cardiovascular diseases: is it preventable? Curr Cardiovasc Risk Rep. 2015;9:30 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4470563/.
Niu Y, Cai J, Xia Y, Yu H, Chen R, Lin Z, et al. Estimation of personal ozone exposure using ambient concentrations and influencing factors. Environ Int. 2018;117:237–42. http://www.sciencedirect.com/science/article/pii/S0160412018304021.
Dionisio KL, Baxter LK, Burke J, Özkaynak H. The importance of the exposure metric in air pollution epidemiology studies: When does it matter, and why? Air Qual Atmos Heal. 2016;9:495–502. https://doi.org/10.1007/s11869-015-0356-1.
Lim S, Kim J, Kim T, Lee K, Yang W, Jun S, et al. Personal exposures to PM2.5 and their relationships with microenvironmental concentrations. Atmos Environ. 2012;47:407–12. http://www.sciencedirect.com/science/article/pii/S1352231011011228.
De Nazelle A, Seto E, Donaire-Gonzalez D, Mendez M, Matamala J, Nieuwenhuijsen MJ, et al. Improving estimates of air pollution exposure through ubiquitous sensing technologies. Environ Pollut. 2013;176:92–9.
Wang S, Zhao Y, Chen G, Wang F, Aunan K, Hao J. Assessment of population exposure to particulate matter pollution in Chongqing, China. Environ Pollut. 2008;153:247–56. http://www.sciencedirect.com/science/article/pii/S0269749107003958.
Zhang Y, Mo J, Li Y, Sundell J, Wargocki P, Zhang J, et al. Can commonly-used fan-driven air cleaning technologies improve indoor air quality? A literature review. Atmos Environ. 2011;45:4329–43. http://www.sciencedirect.com/science/article/pii/S1352231011005346.
Bekö G, Fadeyi MO, Clausen G, Weschler CJ. Sensory pollution from bag-type fiberglass ventilation filters: Conventional filter compared with filters containing various amounts of activated carbon. Build Environ. 2009;44:2114–20. http://www.sciencedirect.com/science/article/pii/S0360132309000651.
Gallego E, Roca FJ, Perales JF, Guardino X. Experimental evaluation of VOC removal efficiency of a coconut shell activated carbon filter for indoor air quality enhancement. Build Environ. 2013;67:14–25. http://www.sciencedirect.com/science/article/pii/S0360132313001418.
Silvers A, Florence BT, Rourke DL, Lorimor RJ. How children spend their time - a sample survey for use in exposure and risk assessments. RISK Anal. 1994;14:931–44.
Zhang L, Guo C, Jia X, Xu H, Pan M, Xu D, et al. Personal exposure measurements of school-children to fine particulate matter (PM2.5) in winter of 2013, Shanghai, China. PLoS ONE. 2018;13:e0193586.
Du X, Kong Q, Ge W, Zhang S, Fu L. Characterization of personal exposure concentration of fine particles for adults and children exposed to high ambient concentrations in Beijing, China. J Environ Sci. 2010;22:1757–64. http://www.sciencedirect.com/science/article/pii/S1001074209603168.
Tang R, Tian L, Thach T-Q, Tsui TH, Brauer M, Lee M, et al. Integrating travel behavior with land use regression to estimate dynamic air pollution exposure in Hong Kong. Environ Int. 2018;113:100–8. http://www.sciencedirect.com/science/article/pii/S0160412017316148.
Chen C, Cai J, Wang C, Shi J, Chen R, Yang C, et al. Estimation of personal PM2.5 and BC exposure by a modeling approach - Results of a panel study in Shanghai, China. Environ Int. 2018;118:194–202.
Karakatsani A, Samoli E, Rodopoulou S, Dimakopoulou K, Papakosta D, Spyratos D, et al. Weekly personal ozone exposure and respiratory health in a panel of greek schoolchildren. Environ Health Perspect. 2017;125:077016.
Adams C, Riggs P, Volckens J. Development of a method for personal, spatiotemporal exposure assessment. J Environ Monit. 2009;11:1331–9. https://doi.org/10.1039/B903841H.
Rabinovitch N, Adams CD, Strand M, Koehler K, Volckens J. Within-microenvironment exposure to particulate matter and health effects in children with asthma: a pilot study utilizing real-time personal monitoring with GPS interface. Environ Heal. 2016;15:96 https://doi.org/10.1186/s12940-016-0181-5.
Branco PTBS, Alvim-Ferraz MCM, Martins FG, Sousa SIV. The microenvironmental modelling approach to assess children’s exposure to air pollution – A review. Environ Res. 2014;135:317–32. http://www.sciencedirect.com/science/article/pii/S0013935114003429.
Koehler K, Good N, Wilson A, Mölter A, Moore BF, Carpenter T, et al. The Fort Collins commuter study: Variability in personal exposure to air pollutants by microenvironment. Indoor Air. 2019;29:231–41. https://doi.org/10.1111/ina.12533. https://onlinelibrary.wiley.com/doi/abs/.
Breen MS, Long TC, Schultz BD, Crooks J, Breen M, Langstaff JE, et al. GPS-based microenvironment tracker (MicroTrac) model to estimate time-location of individuals for air pollution exposure assessments: Model evaluation in central North Carolina. J Expo Sci Environ Epidemiol. 2014;24:412–20.
Quinn C, Miller-Lionberg DD, Klunder KJ, Kwon J, Noth EM, Mehaffy J, et al. Personal exposure to PM 2.5 black carbon and aerosol oxidative potential using an automated microenvironmental aerosol sampler (AMAS). Environ Sci Technol. 2018;52:11267–75. https://doi.org/10.1021/acs.est.8b02992. https://pubs.acs.org/doi/.
Lei X, Xiu G, Li B, Zhang K, Zhao M. Individual exposure of graduate students to PM2.5 and black carbon in Shanghai, China. Environ Sci Pollut Res. 2016;23:12120–7.
Steinle S, Reis S, Sabel CE, Semple S, Twigg MM, Braban CF, et al. Personal exposure monitoring of PM2.5 in indoor and outdoor microenvironments. Sci Total Environ. 2015;508:383–94. http://www.sciencedirect.com/science/article/pii/S0048969714017057.
Yu X, Ivey C, Huang Z, Gurram S, Sivaraman V, Shen H, et al. Quantifying the impact of daily mobility on errors in air pollution exposure estimation using mobile phone location data. Environ Int. 2020;141:105772. http://www.sciencedirect.com/science/article/pii/S0160412019332386.
Mi YH, Norback D, Tao J, Mi YL, Ferm M. Current asthma and respiratory symptoms among pupils in Shanghai, China: influence of building ventilation, nitrogen dioxide, ozone, and formaldehyde in classrooms. Indoor Air. 2006;16:454–64. https://doi.org/10.1111/j.1600-0668.2006.00439.x. https://onlinelibrary.wiley.com/doi/abs/.
Chen C, Li C, Li Y, Liu J, Meng C, Han J, et al. Short-term effects of ambient air pollution exposure on lung function: a longitudinal study among healthy primary school children in China. Sci Total Environ. 2018;645:1014–20.
Johnson T, Capel J, Ollison W. Measurement of microenvironmental ozone concentrations in Durham, North Carolina, using a 2B Technologies 205 Federal Equivalent Method monitor and an interference-free 2B Technologies 211 monitor. J Air \ Waste Manag Assoc. 2014;64:360–71. https://doi.org/10.1080/10962247.2013.839968.
Zuo J, Ji W, Ben Y, Hassan MA, Fan W, Bates L, et al. Using big data from air quality monitors to evaluate indoor PM2.5 exposure in buildings: case study in Beijing. Environ Pollut. 2018;240:839–47. http://www.sciencedirect.com/science/article/pii/S0269749118307681.
Sagona JA, Weisel CP, Meng Q. Accuracy and practicality of a portable ozone monitor for personal exposure estimates. Atmos Environ. 2018;175:120–6. http://www.sciencedirect.com/science/article/pii/S1352231017307811.
Xia Y, Niu Y, Cai J, Lin Z, Liu C, Li H, et al. Effects of personal short-term exposure to ambient ozone on blood pressure and vascular endothelial function: a mechanistic study based on DNA methylation and metabolomics. Environ Sci Technol. 2018;52:12774–82. https://doi.org/10.1021/acs.est.8b03044.
Liu M, Barkjohn KK, Norris C, Schauer JJ, Zhang J, Zhang Y, et al. Using low-cost sensors to monitor indoor, outdoor, and personal ozone concentrations in Beijing, China. Environ Sci Process Impacts. 2020;22:131–43. https://doi.org/10.1039/C9EM00377K.
Zhang J, Sun H, Chen Q, Gu J, Ding Z, Xu Y. Effects of individual ozone exposure on lung function in the elderly: a cross-sectional study in China. Environ Sci Pollut Res. 2019;26:11690–5. https://doi.org/10.1007/s11356-019-04324-w.
Cui X, Li F, Xiang J, Fang L, Chung MK, Day DB, et al. Cardiopulmonary effects of overnight indoor air filtration in healthy non-smoking adults: a double-blind randomized crossover study. Environ Int. 2018;114:27–36. http://www.sciencedirect.com/science/article/pii/S0160412017321037.
Barkjohn KK, Bergin MH, Norris C, Schauer JJ, Zhang Y, Black M, et al. Using low-cost sensors to quantify the effects of air filtration on indoor and personal exposure relevant PM2.5 concentrations in Beijing, China. Aerosol Air Qual Res. 2020;20:297–313. https://doi.org/10.4209/aaqr.2018.11.0394.
Zhan Y, Johnson K, Norris C, Shafer MM, Bergin MH, Zhang Y, et al. The influence of air cleaners on indoor particulate matter components and oxidative potential in residential households in Beijing. Sci Total Environ. 2018;626:507–18. http://www.sciencedirect.com/science/article/pii/S004896971830024X.
Barkjohn KK, Norris C, Cui X, Fang L, Zheng T, Schauer JJ, et al. Real-time measurements of PM2.5 and ozone to assess the effectiveness of residential indoor air filtration in Shanghai homes. Indoor Air. 2020n/a. https://doi.org/10.1111/ina.12716.
Fang L, Norris C, Johnson K, Cui X, Sun J, Teng Y, et al. Toxic volatile organic compounds in 20 homes in Shanghai: concentrations, inhalation health risks, and the impacts of household air cleaning. Build Environ. 2019;157:309–18. http://www.sciencedirect.com/science/article/pii/S0360132319302999.
Norris C, Fang L, Barkjohn KK, Carlson D, Zhang Y, Mo J, et al. Sources of volatile organic compounds in suburban homes in Shanghai, China, and the impact of air filtration on compound concentrations. Chemosphere. 2019;231:256–68. http://www.sciencedirect.com/science/article/pii/S0045653519309579.
Brehmer C, Norris C, Barkjohn KK, Bergin MH, Zhang J, Cui X, et al. The impact of household air cleaners on the chemical composition and children’s exposure to PM2.5 metal sources in suburban Shanghai. Environ Pollut. 2019;253:190–8. https://linkinghub.elsevier.com/retrieve/pii/S0269749119319426.
Brehmer C, Norris C, Barkjohn KK, Bergin MH, Zhang J, Cui X, et al. The impact of household air cleaners on the oxidative potential of PM2.5 and the role of metals and sources associated with indoor and outdoor exposure. Environ Res. 2019;108919. http://www.sciencedirect.com/science/article/pii/S0013935119307169.
He L, Li Z, Teng Y, Cui X, Barkjohn KK, Norris C, et al. Associations of personal exposure to air pollutants with airway mechanics in children with asthma. Environ Int. 2020;138:105647.
Cui X, Li Z, Teng Y, Barkjohn KK, Norris CL, Fang L, et al. Association between bedroom particulate matter filtration and changes in airway pathophysiology in children with asthma. JAMA Pediatr. 2020;174:533–42.
He L, Cui X, Li Z, Teng Y, Barkjohn KK, Norris C, et al. Malondialdehyde in nasal fluid: a biomarker for monitoring asthma control in relation to air pollution exposure. Environ Sci Technol. 2020. https://doi.org/10.1021/acs.est.0c02558.
Ozler S, Johnson KK, Bergin MH, Schauer JJ. Personal exposure to PM2.5 in the various microenvironments as a traveler in the Southeast Asian countries. Am J Environ Sci. 2018;14:170–84. https://doi.org/10.3844/ajessp.2018.170.184. https://thescipub.com/abstract/.
Lal RM, Das K, Fan Y, Barkjohn KK, Botchwey N, Ramaswami A, et al. Connecting air quality with emotional well-being and neighborhood infrastructure in a US city. Environ Health Insights. 2020;14:1178630220915488.
Zheng T, Bergin MH, Johnson KK, Tripathi SN, Shirodkar S, Landis MS, et al. Field evaluation of low-cost particulate matter sensors in high-and low-concentration environments. Atmos Meas Tech. 2018;11:4823–46. https://www.atmos-meas-tech.net/11/4823/2018/.
R Core Team. R: A Language and Environment for Statistical Computing. Vienna: Austria; 2018. https://www.r-project.org/
Nebeker C, Linares R, Crist K. A multi-case study of research using mobile imaging, sensing and tracking technologies to objectively measure behavior: ethical issues and insights to guide responsible research practice. J Res Adm. 2015;46:118.
Hazlehurst MF, Spalt EW, Curl CL, Davey ME, Vedal S, Burke GL, et al. Integrating data from multiple time-location measurement methods for use in exposure assessment: the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). J Expo Sci Environ Epidemiol. 2017;27:569–74.
Ji W, Zhao B. Contribution of outdoor-originating particles, indoor-emitted particles and indoor secondary organic aerosol (SOA) to residential indoor PM2.5 concentration: a model-based estimation. Build Environ. 2015;90:196–205. http://www.sciencedirect.com/science/article/pii/S036013231500164X.
Walker IS, Sherman MH. Effect of ventilation strategies on residential ozone levels. Build Environ. 2013;59:456–65. http://www.sciencedirect.com/science/article/pii/S0360132312002557.
Boelter KJ, Davidson JH. Ozone generation by indoor, electrostatic air cleaners. Aerosol Sci Technol. 1997;27:689–708. https://doi.org/10.1080/02786829708965505.
Darling E, Morrison GC, Corsi RL. Passive removal materials for indoor ozone control. Build Environ. 2016;106:33–44. http://www.sciencedirect.com/science/article/pii/S0360132316302256.
This work was funded by a grant from Underwriters Laboratory (UL) and supported in part by a grant from the National Natural Science Foundation of China (51420105010). The study was approved by both Duke Campus Institutional Review Board (IRB) and by First People’s Hospital IRB. We thank Amway (China) Co., Limited, for lending the air cleaners for use in this study; however, the company was not involved in study design, implementation, or data interpretation. We greatly appreciate all our participants for welcoming us into your homes and allowing us to gather data on your health and air pollution exposure. Thank you to Donghong Chen and the team at the Qingpu Environmental Monitoring station for providing access to their monitoring site and the data from our study period. We sincerely appreciate the support from the other members of the Bergin lab for their assistance in assembling and designing the air sensor packages. Thanks to Yanbo Teng at Duke Kunshan for his strong technical and administrative support throughout the project. Thanks to Jiaqi Sun from Tsinghua University, Jiang Yanyu (Jade) from Shanghai Jiaotong University as well as Dr. Zhen Li, Dr. Qian Wang and Dr. Lili Lin and the resident physicians at Shanghai General Hospital for assisting with home visits and clinical visits throughout the study.
This work was funded by a grant from Underwriters Laboratory (UL) and supported in part by a grant from the National Natural Science Foundation of China (51420105010). Amway (China) Co., Limited, lent the air cleaners for use in this study; however, the company was not involved in study design, implementation, or data interpretation.
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Barkjohn, K.K., Norris, C., Cui, X. et al. Children’s microenvironmental exposure to PM2.5 and ozone and the impact of indoor air filtration. J Expo Sci Environ Epidemiol 30, 971–980 (2020). https://doi.org/10.1038/s41370-020-00266-5
- Air quality
- Indoor environment
- Children’s health
- Exposure sensors
- Monitoring methods
- Exposure assessment
Air Quality, Atmosphere & Health (2021)