title: Exposure and health impact evaluation based on simultaneous measurement of indoor and ambient PM2.5in Haidian, Beijing.
abstract: Because people spend most of their time indoors, the characterization of indoor air quality is important for exposure assessment. Unfortunately, indoor air data are scarce, leading to a major data gap in risk assessment. In this study, PM2.5concentrations in both indoor and outdoor air were simultaneously measured using on-line particulate counters in 13 households in Haidian, Beijing for both heating and non-heating seasons. A bimodal distribution of PM2.5concentrations suggests rapid transitions between polluted and non-polluted situations. The PM2.5concentrations in indoor and outdoor air varied synchronously, with the indoor variation lagging. The lag time in the heating season was longer than that in the non-heating season. The particle sizes in indoor air were smaller than those in ambient air in the heating season and vice versa in the non-heating season. PM2.5concentrations in indoor air were generally lower than those in ambient air except when ambient concentrations dropped sharply to very low levels or there were internal emissions from cooking or other activities. The effectiveness of an air cleaner to reduce indoor PM2.5concentrations was demonstrated. Non-linear regression models were developed to predict indoor air PM2.5concentrations based on ambient data with lag time incorporated. The models were applied to estimate the overall population exposure to PM2.5and the health consequences in Haidian. The health impacts would be significantly overestimated without the indoor exposure being taken into consideration, and this bias would increase as the ambient air quality improved in the future.
authors: Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, PR China.
authors: Meng
authors: M
authors: Qi
authors: Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, PR China.
authors: Xi
authors: X
authors: Zhu
authors: Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, PR China.
authors: Wei
authors: W
authors: Du
authors: Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, PR China.
authors: Yilin
authors: Y
authors: Chen
authors: Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, PR China.
authors: Yuanchen
authors: Y
authors: Chen
authors: Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, PR China.
authors: Tianbo
authors: T
authors: Huang
authors: Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, PR China.
authors: Xuelian
authors: X
authors: Pan
authors: Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, PR China.
authors: Qirui
authors: Q
authors: Zhong
authors: Research Center for Eco-Environmental Sciences, CAS, Beijing, 100085, China.
authors: Xu
authors: X
authors: Sun
authors: School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China.
authors: Eddy Y
authors: EY
authors: Zeng
authors: Stockbridge School of Agriculture, College of Natural Science, University of Massachusetts, Amherst, MA 01003-9246, USA.
authors: Baoshan
authors: B
authors: Xing
authors: Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, PR China. Electronic address: taos@pku.edu.cn.
authors: Shu
authors: S
authors: Tao
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D000068476:Beijing; D003296:Cooking; D004784:Environmental Monitoring / Q000379:methods*; D062489:Health Impact Assessment; D006361:Heating; D006801:Humans; D008962:Models, Theoretical; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D012621:Seasons; D011795:Surveys and Questionnaires
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: I/O; Indoor air; Modeling; PM(2.5); Population exposure