Combined impact of dynamic air pollution and transportation noise on cardiometabolic disorders in San Diego County.

Air pollution and noise exposure may synergistically contribute to increased cardiometabolic disorders; however, few studies have examined this potential interaction or considered exposures beyond residential location. The combined impact of dynamic air pollution and transportation noise on cardiometabolic disorders in San Diego County was investigated. Using data from the Community of Mine Study (2014-2017), 602 ethnically diverse participants were assessed for obesity, dyslipidemia, hypertension, and metabolic syndrome (MetS), using anthropometric measurements and biomarkers from blood samples. Time-weighted measures of exposure to fine particulate matter, nitrogen dioxide (NO2), and road and aircraft noise were calculated using global positioning system mobility data and kernel density estimation. Generalized estimating equation models were used to analyze associations. Interactions were assessed on the multiplicative and additive scales using relative excess risk due to interaction (RERI). We found that air pollution and noise interact to affect metabolic disorders on both multiplicative and additive scales. The effect of noise on obesity and MetS was higher when air pollution level was higher. The RERIs of aircraft noise and NO2 on obesity and MetS were 0.13 (95% CI, 0.03-0.22) and 0.13 (95% CI, 0.02-0.25), respectively. These findings suggest aircraft noise and air pollution may have synergistic effects on obesity and MetS. This article is part of a Special Collection on Environmental Epidemiology.