Association of the components of ambient fine particulate matter (PM) and chronic kidney disease prevalence in China.

Previous research has implicated PM as a potential environmental risk factor for CKD, but little is known about the associations between its components and CKD. We conducted a nationwide cross-sectional study using the updated air pollution data in the nationwide population (N = 2,938,653). Using generalized additive models, we assessed the association between long-term exposure to PM and its components (i.e., black carbon [BC], organic matter [OM], nitrate [NO], ammonium [NH], sulfate [SO]), and CKD prevalence. The air pollution data was estimated using high-resolution and high-quality spatiotemporal datasets of ground-level air pollutants in China. Besides, we adopted a novel quantile-based g-computation approach to assess the effect of a mixture of PM constituents on CKD prevalence. The average concentration of PM was 78.67 ± 22.5 μg/m, which far exceeded WHO AQG. In the fully adjusted generalized additive model, at a 10 km × 10 km spatial resolution, the ORs per IQR increase in previous 1-year average PM exposures was 1.380 (95%CI: 1.345-1.415), for NH was 1.094 (95%CI: 1.062-1.126), for BC was 1.604 (95%CI: 1.563-1.646), for NO was 1.094 (95%CI: 1.060-1.130), for SO was 1.239 (95%CI: 1.208-1.272), and for the OM was 1.387 (95%CI: 1.354-1.421), respectively. Subgroup analysis showed females, younger, and healthier were more vulnerable to this effect. In the further exploration of the joint effect of PM compositions (OR 1.234 [95%CI 1.222-1.246]) per quartile increase in all 5 PM components, we found that PMSO contributed the most. These findings provide important evidence for the positive relationship between long-term exposure to PM and its chemical constituents and CKD prevalence in a Chinese health check-up population, and identified PMSO has the highest contribution to this relationship. This study provides clinical and public health guidance for reducing specific air particle exposure for those at risk of CKD.