Impacts of air pollution and noise on risk of preterm birth and stillbirth in London

Rachel B Smith,Sean D Beevers,John Gulliver,David Dajnak,Daniela Fecht,Marta Blangiardo,Margaret Douglass,Anna L Hansell,H Ross Anderson,Frank J Kelly,Mireille B Toledano

doi:10.1016/j.envint.2019.105290

Abstract

BackgroundEvidence for associations between ambient air pollution and preterm birth and stillbirth is inconsistent. Road traffic produces both air pollutants and noise, but few studies have examined these co-exposures together and none to date with all-cause or cause-specific stillbirths. ObjectivesTo analyse the relationship between long-term exposure to air pollution and noise at address level during pregnancy and risk of preterm birth and stillbirth. MethodsThe study population comprised 581,774 live and still births in the Greater London area, 2006–2010. Outcomes were preterm birth (<37 completed weeks gestation), all-cause stillbirth and cause-specific stillbirth. Exposures during pregnancy to particulate matter with diameter <2.5 μm (PM2.5) and <10 μm (PM10), ozone (O3), primary traffic air pollutants (nitrogen dioxide, nitrogen oxides, PM2.5 from traffic exhaust and traffic non-exhaust), and road traffic noise were estimated based on maternal address at birth. ResultsAn interquartile range increase in O3 exposure was associated with elevated risk of preterm birth (OR 1.15 95% CI: 1.11, 1.18, for both Trimester 1 and 2), all-cause stillbirth (Trimester 1 OR 1.17 95% CI: 1.07, 1.27; Trimester 2 OR 1.20 95% CI: 1.09, 1.32) and asphyxia-related stillbirth (Trimester 1 OR 1.22 95% CI: 1.01, 1.49). Odds ratios with the other air pollutant exposures examined were null or <1, except for primary traffic non-exhaust related PM2.5, which was associated with 3% increased odds of preterm birth (Trimester 1) and 7% increased odds stillbirth (Trimester 1 and 2) when adjusted for O3. Elevated risk of preterm birth was associated with increasing road traffic noise, but only after adjustment for certain air pollutant exposures. DiscussionOur findings suggest that exposure to higher levels of O3 and primary traffic non-exhaust related PM2.5 during pregnancy may increase risk of preterm birth and stillbirth; and a possible relationship between long-term traffic-related noise and risk of preterm birth. These findings extend and strengthen the evidence base for important public health impacts of ambient ozone, particulate matter and noise in early life.

Highlights

There is strong evidence that exposure to ambient air pollution during pregnancy is associated with increased risk of infant mortality and reduced birth weight (Lacasana et al, 2005; Sun et al, 2016), but evidence for associations with preterm birth (PTB) and stillbirth is less consistent (Klepac et al, 2018; Siddika et al, 2016)
All births (N = 687,147) occurring during 2006–2010 to mothers residing within middle layer super output areas (MSOAs) completely within the M25 were extracted from the UK National Births/Stillbirth registers supplied by the Office for National Statistics (ONS)
Prevalence of PTB and stillbirth, and mean air pollutant exposures (NO2, nitrogen oxide (NOX), PM2.5 traffic-exhaust, PM2.5, PM10) decreased, and mean noise exposures increased in the population from 2006 to 2010 (Supplementary Tables 2 & 3)

Summary

Introduction

There is strong evidence that exposure to ambient air pollution during pregnancy is associated with increased risk of infant mortality and reduced birth weight (Lacasana et al, 2005; Sun et al, 2016), but evidence for associations with preterm birth (PTB) and stillbirth is less consistent (Klepac et al, 2018; Siddika et al, 2016). Evidence for associations between ambient air pollution and preterm birth and stillbirth is inconsistent Road traffic produces both air pollutants and noise, but few studies have examined these co-exposures together and none to date with all-cause or cause-specific stillbirths. Discussion: Our findings suggest that exposure to higher levels of O3 and primary traffic non-exhaust related PM2.5 during pregnancy may increase risk of preterm birth and stillbirth; and a possible relationship between long-term traffic-related noise and risk of preterm birth. These findings extend and strengthen the evidence base for important public health impacts of ambient ozone, particulate matter and noise in early life

Objectives

Methods

Results

Discussion

Conclusion