Associations between long-term exposure to ambient air pollution and renal function in Southwest China: The China Multi-Ethnic Cohort (CMEC) study

Limited studies have examined associations between air pollutants exposure and renal function, especially in China, with the most extensive chronic kidney disease (CKD) disease burden worldwide.This study examines associations between long-term exposure to ambient PM2.5, NO2, CO, O3, SO2 and renal function.We included 80,225 participants aged 30-79 years from the baseline data of the China Multi-Ethnic Cohort (CMEC) study. Three-year average concentrations of PM2.5, NO2, CO, O3, and SO2 were estimated using satellite-based spatiotemporal models. Renal function is determined by the estimated glomerular filtration rate (eGFR) using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. After adjusting for covariates, generalized propensity scores (GPS) weighting regression was used to estimate associations between ambient air pollutants and renal function.An increase of 0.1 mg/m3 CO (OR [odds ratio] =1.20 95% CI [confidence interval], 1.05-1.37) was positively associated with CKD. An increase of 1 μg/m3 in SO2 (1.07, 1.00-1.14) concentration was positively associated with CKD. An increase of 10 μg/m3 in PM2.5 (1.17, 0.99-1.38), NO2 (1.12, 0.83-1.51) and O3 (1.10, 0.81-1.50) concentration was not associated with CKD. These effects are stronger in those younger than 65, smoking and with low BMI.In this study, we found that long-term exposure to ambient CO and SO2 were positively associated with CKD. Gaseous pollutants should also arouse the concern of relevant departments.