Effects of Air Pollution on the Risk of Low Birth Weight in a Cold Climate

Hamudat A Balogun,Nazeeba Siddika,Mikhail Sofiev,Aino K Rantala,A Kofi Amegah,Niilo R I Ryti,Jaakko Kukkonen,Jouni J K Jaakkola,Maritta S Jaakkola,Harri Antikainen

doi:10.3390/app10186399

Abstract

There is accumulating evidence that prenatal exposure to air pollution disturbs fetal growth and development, but little is known about these effects in cold climates or their season-specific or joint effects. Our objective was to assess independent and joint effects of prenatal exposure to specific air pollutants on the risk of low birth weight (LBW). We utilized the 2568 children of the Espoo Cohort Study, born between 1984 and 1990 and living in the City of Espoo. We conducted stratified analyses for births during warm and cold seasons separately. We analyzed the effect estimates using multi-pollutant Poisson regression models with risk ratio (RR) as the measure of effect. The risk of LBW was related to exposure to CO (adjusted RR 1.44, 95% confidence interval [CI]: 1.04–2.00) and exposure to O3 in the spring–summer season (1.82, 1.11–2.96). There was also evidence of synergistic effects between CO and O3 (relative risk due to interaction (RERI), all year 1.08, 95% CI: 0.27–4.94, spring–summer 3.97, 2.17–25.85) and between PM2.5 and O3 (all year 0.72, −0.07–3.60, spring–summer 2.80, 1.36–19.88). We present new evidence of both independent and joint effects of prenatal exposure to low levels of air pollution in a cold climate on the risk of LBW.

Highlights

Birth weight is commonly used as a measure of fetal growth
We identified a set of determinants of low birth weight (LBW) based on previous literature and assessed their potential role as confounders in the multivariable statistical models
48.0% of our participant mothers were above 30 years and 23.4% belonged to the highest categories of socioeconomic status

Summary

Introduction

Birth weight is commonly used as a measure of fetal growth. The World Health Organization (WHO) defines low birth weight (LBW) as any live birth weighing less than 2500 g [1]. In Finland, the prevalence of low birth weight is approximately 4.3% [4,5]. Humans are surrounded by air pollution throughout their life; the prenatal period is possibly the most vulnerable period. During this period, children are especially susceptible to adverse effects of environmental exposures [6]. The evidence on the impact of prenatal exposure to air pollutants on fetal growth and development has been summarized in several systematic

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