Association between exposure to multiple air pollutants, transportation noise and cause-specific mortality in adults in Switzerland

Long-term exposure to air pollution and noise is detrimental to health; but studies that evaluated both remain limited. This study explores associations with natural and cause-specific mortality for a range of air pollutants and transportation noise. Over 4 million adults in Switzerland were followed from 2000 to 2014. Exposure to PM , PM components (Cu, Fe, S and Zn), NO , black carbon (BC) and ozone (O ) from European models, and transportation noise from source-specific Swiss models, were assigned at baseline home addresses. Cox proportional hazards models, adjusted for individual and area-level covariates, were used to evaluate associations with each exposure and death from natural, cardiovascular (CVD) or non-malignant respiratory disease. Analyses included single and two exposure models, and subset analysis to study lower exposure ranges. During follow-up, 661,534 individuals died of natural causes (36.6% CVD, 6.6% respiratory). All exposures including the PM components were associated with natural mortality, with hazard ratios (95% confidence intervals) of 1.026 (1.015, 1.038) per 5 µg/m PM , 1.050 (1.041, 1.059) per 10 µg/m NO , 1.057 (1.048, 1.067) per 0.5 × 10 /m BC and 1.045 (1.040, 1.049) per 10 dB Lden total transportation noise. NO , BC, Cu, Fe and noise were consistently associated with CVD and respiratory mortality, whereas PM was only associated with CVD mortality. Natural mortality associations persisted