Personal exposure to PM 2.5 of indoor and outdoor origin in two neighboring Chinese communities with contrasting household fuel use patterns.

The Chinese government is replacing high-polluting, household coal heating stoves with electricity- and natural gas-powered heaters to improve ambient air quality. The evaluation of the intervention impact on outdoor PM _2.5 and personal exposure in community level are in their initial stages. We compared outdoor air pollution and personal exposure in two neighboring communities (~2 km) in northern China with contrasting household fuel use patterns: one where residents primarily used coal for cooking and heating ("coal village") and one where natural gas was the dominant fuel ("gas village"). We collected 24-h outdoor gravimetric PM _2.5 samples in each village and concurrently measured 48-h integrated exposures among 71 participants from 41 and 30 households in the coal and gas villages, respectively. PM _2.5 samples were analyzed for mass and chemical composition. Daily outdoor PM _2.5 concentrations in the coal village (mean ± standard deviation: 109 ± 41 μg/m ³ ) were, on average, 1.3 ± 0.2 times higher than in the gas village (88 ± 38 μg/m ³ ). However, personal PM _2.5 exposures were lower in the coal village (116 ± 121 μg/m ³ versus 156 ± 106 μg/m ³ ). PM _2.5 species that can serve as tracers for residential coal combustion (e.g., S, Se, Zn, Pb, etc.) and dust (Al, Ca, Mg, Fe, Si and Ti) were higher in the coal village, and the proportion of personal PM _2.5 of outdoor origin in the coal village was nearly 2 times higher than the gas village. Our results suggest that ambient PM _2.5 and its chemical composition can vary at relatively small spatial scales and may reflect community-level differences in the household energy use. However, personal PM _2.5 exposures may not mirror between-village differences in outdoor air pollution if only PM _2.5 mass is evaluated. Individual chemical composition of PM _2.5 exposure can provide important insight in future studies on the effectiveness of source-targeted air quality interventions.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2021. Published by Elsevier B.V.)