Aircraft noise and vehicle traffic-related air pollution interact to affect preterm birth risk in Los Angeles, California

Abstract

IntroductionAir pollution has been linked to preterm birth (PTB) while findings for noise exposure have been mixed. Few studies – none considering airports – have investigated combined exposures. We explore the relationship between joint exposure to airport-related noise, airport ultrafine particles (UFP), and vehicle traffic-related air pollution (TRAP) on risk of PTB near Los Angeles International Airport (LAX). MethodsWe used comprehensive birth data for mothers living ≤15 km from LAX from 2008 to 2016 (n = 174,186) Noise data were generated by monitor-validated models. NO2 was used as a TRAP proxy, estimated with a seasonally-adjusted, validated land-use regression model. We estimated the effects of exposure to airport-related noise and TRAP on PTB employing logistic regression models that adjusted for known maternal risk factors for PTB as well as aircraft-origin UFP and neighborhood characteristics. ResultsThe adjusted odds ratio (aOR) for PTB from high noise exposure (i.e. > 65 dB) was 1.10 (95% CI: 1.01–1.19). Relative to the first quartile, the aORs for PTB in the second, third, and fourth TRAP quartiles were 1.10 (95% CI: 1.05–1.16), 1.11 (95% CI: 1.05–1.16), and 1.15 (95% CI: 1.10–1.22), respectively. When stratifying by increasing TRAP quartiles, the aORs for PTB with high airport-related noise were 1.04 (95% CI: 0.91–1.18), 1.02 (95% CI: 0.88–1.19), 1.24 (95% CI: 1.03–1.48), and 1.44 (95% CI: 1.08–1.91) (p-interaction = 0.06). ConclusionOur results suggest a potential synergism between airport-related noise and TRAP exposures on increasing the risk of PTB in this metropolitan area.