Air pollutants associated with insufficient birth weight.

INTRODUCTION A growing number of studies have shown consistent evidence of the harmful effects of air pollution on human health, as well as its effects on newborn weight. The objective of this study is to evaluate the effect of air pollution on birth weight, more specifically the insufficient birth weight (identified between 2,500 and 2,999 grams). METHODS This was a cross-sectional study based on data gathered from all babies born to mothers living in São José dos Campos, São Paulo, Brazil, between the years of 2006 to 2010. The association between maternal exposure to air pollution and birth weight was examined using logistic regression (both univariate and multivariate) to consider the average concentration of each pollutant during the 1st and 3rd trimesters and the months of the 1st trimester. RESULTS Of the 39,453 total live births during the study period, 10,542 (26.7%) newborns had insufficient weight. In multiple logistic analysis, maternal exposure to particulate matter in the 1st and 3rd trimester of pregnancy had a greater chance for insufficient weight. There is a chance of 1.07 (95%CI 1.00 - 1.14) for an insufficient weight scenario for exposure (to the 2nd quartile) of particulate matter in the 1st trimester and 1.10 (95%CI 1.04 - 1.18) for exposure (the 3rd quartile) in the 3rd trimester. CONCLUSION The survey results indicate that maternal exposure to air pollution in the 1st and 3rd trimesters of pregnancy for residents of São José dos Campos create considerable potential to cause insufficient weight.