Perinatal exposure to air pollution and childhood asthma incidence in the first 6 years
Maternal asthma enhances the effect of air pollution during pregnancy on the risk of developing asthma in children.
Many epidemiological studies reported associations between air pollution and childhood asthma incidence, with some of them suggesting that this relationship may begin in utero. A recent study conducted in Canada on 110981 children with asthma examined whether maternal and infant characteristics modified the association between perinatal exposure to air pollution and development of childhood asthma. The Authors observed that second-trimester exposures to PM2.5 and NO2 were associated with childhood asthma development. Noteworthy, impacts on childhood asthma diagnosed before 6 years of age increased in a synergistic manner when evaluating the joint effect of maternal asthma and high levels of exposure to NO2 during the second trimester of pregnancy. Moreover, enhanced impacts were found among children born to mothers who smoked during pregnancy or lived in urban areas during pregnancy, males and children born preterm or of low birthweight. Hence, prenatal exposure to air pollution may have a differential impact on the risk of asthma development, according to maternal and infant characteristics. These data underline the need for further studies to confirm the aforementioned relationships and also the importance of developing public health and prenatal care strategies aimed at raising awareness and minimizing exposure to pollutants during pregnancy.