Relação entre baixo peso ao nascer e a poluição do ar no Município de São Paulo

Abstract

ObjectiveAir pollution has been investigated as a potential determinant for low birthweight. The aim of the present study was to study the effect of air pollution on birthweight. MethodsWe analyzed all deliveries by mothers living in the municipality of São Paulo, Southeastern Brazil, between 1998 and 2000. We estimated the prevalence of low birthweight according to newborn, mother, and delivery characteristics. Only births occurring in the most central districts of the city were analyzed, totaling 311.735 events. For the evaluation of the effects of air pollution, we excluded preterm and multiple deliveries. Pollutants analyzed were ozone (O 3 ), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), suspended particles (PM 10 ), and carbon monoxide (CO). The effect of maternal exposure to air pollution on birthweight was evaluated using linear and logistic regression. Results A total of 4.6% of newborns weighed less than 2,500 g at birth. Maternal exposure to CO, PM 10 , and NO 2 during the first trimester of pregnancy was significantly associated with decreased birthweight. ConclusionsOur results reinforce the notion that maternal exposure to air pollution during the first trimester of pregnancy may contribute to lesser weight gain in the fetus.

Are environmental pollutants risk factors for low birth weight?

“…Meanwhile, our findings disagree with those of Medeiros & Gouveia 8 and Bell et al 14 . Kannan et al 19 propose mechanisms resulting in low birth weight due to exposure to PM 10 .…”

“…The most important finding in this study, unlike others conducted in Brazil 8,9 , was the role of ozone in low birth weight. Meanwhile, the study is consistent with Salam et al 12 , who point to a 40% increase in the odds of low birth weight.…”

“…Unlike other studies 7,8,13,14 , the current study opted to investigate the effects of pollutants after excluding potential confounding factors. The option to study the final weeks of pregnancy was due to the fact that this period shows a major fetal weight gain, representing slightly more than 1,500g in final birth weight 11 .…”

“…Another potential limitation was the lack of information on maternal weight gain during the pregnancy, maternal height, public versus private prenatal care, and adequacy of nutrient intake. Such information is not included on certificates of live birth, and this gap has been identified in studies performed in Brazil 8,9 .…”

“…In Brasil, Medeiros & Gouveia 8 found an association between low birth weight and the pollutants CO, PM 10 , and NO 2 , while Junger & Leon 9 found no significant association between low birth weight and the pollutants PM 10 , ozone, nitrogen oxide (NO 2 ), carbon monoxide (CO), or SO 2 .…”