RESUMO
OBJECTIVE: To examine whether there is an association between fetal and/or placental weight and exposure to ambient levels of air pollution in mice. DESIGN: Chronic experiments on mice that were exposed to polluted vs. clean air. SETTING: Environmental exposure to atmospheric pollution. ANIMAL(S): Female Swiss mice (n = 70) were maintained at different stages of gestation in an exposure chamber located at an intersection with heavy traffic in a major city in Brazil. Control mice were maintained in a similar chamber, located adjacent to the exposure chamber but equipped with filters for particles and reactive gases. INTERVENTION(S): Animals were divided into six groups as follows: no exposure, exposure to a polluted chamber throughout gestation, exposure to a polluted chamber during the 1st week of pregnancy, exposure to a polluted chamber during the 2nd and 3rd weeks, exposure to a polluted chamber during the 1st and 2nd week, and exposure to a polluted chamber during the 3rd week. MAIN OUTCOME MEASURE(S): At the end of the gestational period, the determination of fetal and placental weight was performed after cesarean section. RESULT(S): Exposure to air pollution during the 1st week of pregnancy promoted a significant reduction in fetal weight. Mice exposed to polluted air, in any phase of gestation, presented with lower placental weight in comparison to mice maintained in clean chambers. CONCLUSION(S): Exposure to ambient levels of traffic pollution at early phases of gestation is a determinant for decreased final fetal weight. Placental weight is reduced with exposure to air pollution at any phase of gestation.
Assuntos
Poluentes Atmosféricos/toxicidade , Peso ao Nascer/efeitos dos fármacos , Peso Fetal/efeitos dos fármacos , Placenta/efeitos dos fármacos , Emissões de Veículos/toxicidade , Animais , Animais Recém-Nascidos , Câmaras de Exposição Atmosférica , Cesárea , Feminino , Idade Gestacional , Exposição Materna , Camundongos , Tamanho do Órgão , PlacentaçãoRESUMO
A significant negative association (R(2) = 0.7642; P=.013) between particulate matter and secondary sex ratio was found when evaluating people in the city of São Paulo, Brazil. An animal model with male mice raised in nonfiltered open-top chambers showed a significant reduction in the secondary sex ratio (P=.041), suggesting that ambient air pollution may interfere with sex distribution by altering the X:Y sperm proportion in pollution-exposed males.