A Multi-Provincial Study of Air Pollution Exposure in Rural and Peri-Urban China

Abstract

Background: Coal and biomass burning for household cooking and heating is a major source of exposure to air pollutants including fine particulate matter (PM2.5). Compared with urban air pollution, little is known about air pollution exposures in rural and peri-urban settings, particularly among men.Objective: Assess personal exposures to PM2.5 among men and women ages 40-79 living in peri-urban villages in northern (Beijing, Shanxi) and southern China (Guangxi).Methods: We enrolled 782 participants into the INTERMAP China Prospective Study from these three regions and measured their integrated gravimetric personal exposures to PM2.5 (Apex pumps; Harvard PEMs; 37 mm PTFE filters) for 2 days in heating and non-heating seasons and also collected information on fuel and energy use patterns.Results: Geometric mean daily exposures to PM2.5 across sites and seasons ranged from 60 (95% CI [56, 64], Guangxi - heating season) – 134 (95% CI [122, 147], Shanxi - heating season) ug/m3. A seasonal difference was observed in the northern sites (GM = 96 ug/m3, 95% CI [90, 101] in heating versus 88 ug/m3 [83, 94] in non-heating). Exposures were highest in Shanxi (GM = 120 ug/m3, 95% CI [113, 128]), followed by Beijing (93 ug/m3 [87, 99]) and Guangxi (60 ug/m3 [56, 64]). This trend persisted across season and gender. The proportion of participants using solid fuels was highest in Beijing (95%), followed by Shanxi (75%), and Guangxi (62%). Notably, individuals not using solid fuels for cooking and heating (GM = 92 ug/m3 [83, 102]) had similar exposures to individuals using solid fuels (93 ug/m3 [89, 97]).Conclusion: Use of solid fuels has persisted across northern and southern China. Exposures across all demographic groups and seasons exceeded the WHO 24-h air quality guideline of 25 ug/m3. On average, exposures in southern China were half that of northern China, where heating is an important energy use practice.