Effects of indoor activities and outdoor penetration on PM2.5 and associated organic/elemental carbon at residential homes in four Chinese cities during winter

Zhuozhi Zhang; Yuan Gao; Qi Yuan; Yan Tan; Haiwei Li; Long Cui; Yu Huang; Yan Cheng; Guangli Xiu; Senchao Lai; Judith C Chow; John G Watson; Shun-Cheng Lee

doi:10.1016/j.scitotenv.2020.139684

Effects of indoor activities and outdoor penetration on PM_2.5 and associated organic/elemental carbon at residential homes in four Chinese cities during winter

Sci Total Environ. 2020 Oct 15:739:139684. doi: 10.1016/j.scitotenv.2020.139684. Epub 2020 May 30.

Authors

Zhuozhi Zhang¹, Yuan Gao¹, Qi Yuan¹, Yan Tan¹, Haiwei Li², Long Cui³, Yu Huang³, Yan Cheng⁴, Guangli Xiu⁵, Senchao Lai⁶, Judith C Chow⁷, John G Watson⁷, Shun-Cheng Lee⁸

Affiliations

¹ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.
² Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), Collaborative Innovation Centre of Atmospheric Environment and Equipment Technology (CIC-AEET), School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, China.
³ State Key Laboratory of Loess and Quaternary Geology (SKLLQG), Key Laboratory of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China.
⁴ School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
⁵ School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China.
⁶ The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
⁷ Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, USA.
⁸ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China. Electronic address: shun-cheng.lee@polyu.edu.hk.

PMID: 32554114
DOI: 10.1016/j.scitotenv.2020.139684

Abstract

There is increasing public attention on exposure to PM_2.5 and its related health impacts. It is essential to study the pollution levels, sources, and health implications of indoor PM_2.5, especially for residential homes, as people tend to spend most of their time indoors. The indoor PM_2.5 mass and organic/elemental carbon (OC/EC) during winter and early spring period of 2016-2017 at 68 residential households in four large Chinese cities (i.e. Hong Kong, Guangzhou, Shanghai, and Xi'an) were studied. Average indoor PM_2.5 varied by two-fold, lowest in Hong Kong (34.0 ± 14.6 μg m^-³) and highest in Xi'an (78.7 ± 49.3 μg m^-³), with comparable levels for Guangzhou (47.2 ± 5.4 μg m^-³) and Shanghai (50.3 ± 17.9 μg m^-³). Lowest air exchange rate (AER, 0.8 ± 0.8 h^-¹) and PM_2.5 indoor/outdoor (I/O) ratio (0.72 ± 0.23) were found for Xi'an households, indicating the limited influence from indoor sources, while importance of indoor PM_2.5 sources is signified with the highest PM_2.5 I/O ratio (1.32 ± 0.43) identified for Shanghai households. For households in four cities, OC and EC accounted for 29.5%-38.5% and 7.5%-8.9% of the indoor PM_2.5 mass, indicating the significance of carbonaceous aerosols. Larger differences between indoor and outdoor OC (2.6-8.4%) than EC (-2.2-1.5%) indicate the presence of indoor OC sources. Decreasing trends of PM_2.5 I/O ratio and indoor OC proportion were found as the worsening ambient air quality. On average, 11.8 μg m^-³ (23.1%) and 3.02 μg m^-³ (18.7%) higher indoor PM_2.5 and OC concentrations were identified for households with other indoor combustions (e.g., tobacco smoking, incense burning) compared to those with only cooking activities. For Hong Kong and Shanghai households, increments of 13.2 μg m^-³ (54.1%) of PM_2.5 and 4.1 μg m^-³ (45.4%) of OC were found at households with cooking activities as compared to households with no specific indoor combustion.

Keywords: Ambient penetration; Carbonaceous aerosols; Indoor combustion; PM(2.5) (fine suspended particulate); Residence.

MeSH terms

Aerosols / analysis
Air Pollutants / analysis*
Air Pollution, Indoor / analysis*
Carbon / analysis
China
Cities
Environmental Monitoring
Hong Kong
Particle Size
Particulate Matter / analysis
Seasons

Substances

Aerosols
Air Pollutants
Particulate Matter
Carbon