Preterm Birth and Ambient Air Pollution in Volta Redonda, Rio de Janeiro, Brazil

Abstract

ISEE-0523 Background and Objective: Preterm birth (PTB) is related to some health outcomes such as pulmonary, ophthalmologic and neurologic morbidity, delayed psychomotor development and death. In recent years, several studies have examined the relationship between PTB and air pollution. This study investigated the association between prematurity and air pollution in Volta Redonda, an industrialized city in Rio de Janeiro/Brazil. Methods: In this population-based study we examined prematurity in relation to maternal exposure to outdoor air pollution, among 13,366 singleton births in Volta Redonda from 2003 to 2006. Birth and air monitoring data were obtained from governmental offices. We estimated maternal exposure to particulate matter with an aerodynamic diameter of ≤ 10 μm (PM10), sulfur dioxide (SO2) and ozone (O3) considering their daily arithmetic means concentrations. Date of birth was used to estimate maternal exposure to pollutants over each trimester of pregnancy. We estimated crude and adjusted effects of air pollution exposure on the risk of PTB using logistic regression models. Analyses were performed to single and multiple pollutants models to assess the robustness of each contaminant in the association. We adjusted models for potential confounders of preterm birth. Results: Statistical significant crude and adjusted odds ratios (OR) for PTB was observed to maternal exposure to SO2 during each trimester of pregnancy. Multiple pollutants model indicates the robustness of the relationship between maternal exposure to SO2 and PTB OR First trimester = 1.304; 95% CI: 1.145, 1.487; OR Second trimester = 1.310; 95% CI: 1.187, 1.446; OR Third trimester = 1.252; 95% CI: 1.1152, 1.360). Dose-response patterns were also observed for interquartile range in all three trimesters of pregnancy in their relation to maternal exposure to SO2. Conclusion: Results show that maternal exposure to sulfur dioxide may increase risk of preterm birth.