Review Searches for Vulnerable Subpopulations
In the past decade and a half, more than 30 papers have examined the link between air pollution and the risk of autism spectrum disorder (ASD). Recently, a new systematic review has examined 19 of these papers in an effort to investigate how ASD susceptibility to air pollution varied among vulnerable subpopulations. The review’s results demonstrated that, in general, the risk of ASD in boys was higher than in girls due to air pollution based on the conclusions of 11 of the 19 investigated studies. Additionally, limited data demonstrated that pregnant women with deficient folic acid intake could be more susceptible to ambient particulate matter less than 2.5 μm (PM2.5) and 10 μm (PM10) in aerodynamic diameter, and to nitrogen dioxide (NO2) which could affect the development of the fetus. Mothers who experienced gestational diabetes had an increased risk of having offspring with ozone-associated ASD. Furthermore, two genetic studies showed that copy number variations may increase the effect of ozone, and MET rs1858830 CC genotype may augment effect of particulate matter and near-roadway pollutants on ASD. Ultimately, the review determined that the child’s sex, maternal nutrition or diabetes, socioeconomic factors, and child risk genotypes were reported to modify the effect of early-life exposure to air pollutants on ASD risk. The review’s authors warn that the sparsity of studies on comparable modifying hypotheses prevents making conclusive findings. The team calls for further research to identify additional susceptible populations and potential targets for preventative measures.
