Disparities in residential PM2.5 and disease burden across urban and peri-urban: A 2018–2019 multicenter on-site survey in China

Residential fine particulate matter (PM_2.5) poses a substantial health hazard, yet disparities across urban and peri-urban areas remain unclear in China due to the absence of systematic monitoring data. Key knowledge gaps persist regarding the characteristics, influencing factors, and health burdens of residential PM_2.5 pollution, particularly in peri-urban regions. Between 2018 and 2019, 746 urban and 339 peri-urban households in 15 typical Chinese cities were randomly selected through the Chinese Indoor Environment and Health Surveillance Project (CIEHS). The relationships between influencing factors and residential PM_2.5 were assessed using a general linear model (GLM), and factors importance was identified using the Boruta algorithm with 10-fold cross-validation and 100 replications. Disability-adjusted life-years (DALYs) attributable to the residential PM_2.5 were estimated using the population-attributable fraction method. The mean residential PM_2.5 concentration was 62.2 μg/m³, with higher levels in peri-urban (Odds ratio [OR] = 1.0705 95 % Confidence interval [95 % CI]: 1.0615, 1.0795) and during cold seasons (OR = 1.3499 95 %CI: 1.3388, 1.3610). Environmental factors, building conditions, family-related information, and lifestyle behaviors were all associated with residential PM_2.5, notably, with the five most influential factors remaining consistent across urban and peri-urban areas. The mean DALY rate was 2160 per 100,000 in urban areas, slightly higher at 2186 per 100,000 in peri-urban areas. According to China's seventh national census, residential PM_2.5 exposure accounted for 19.48 million urban and 11.14 million peri-urban DALYs nationally. These findings underscore the urgency for differentiated environmental management and targeted mitigation policies to address the disproportionate health burden in peri-urban areas.