Air Quality May
Be A Factor
Air pollution is no good for anyone -- even (or especially) unborn babies. A new study has identified several air pollutants as being autism risk factors for the babies of mothers exposed to them.
Diesel fuel and mercury were found to have the greatest effect on a child’s chances of being on the autism spectrum. Researchers from Harvard School of Public Health studied 325 women who had a child with autism and 22,000 moms whose children were not on the spectrum. They then estimated the levels of air pollution at the time and place of each baby’s birth.
They found that moms who were in areas that had the highest concentrations of diesel or mercury were twice as likely to have a baby that would eventually be diagnosed as being on the autism spectrum when compared to women who lived in areas with the lowest amounts of air pollution.
Other common air pollutants, such as lead, manganese and methylene chloride, were also found to be a factor. They discovered that moms in areas with the highest concentration of these pollutants were 50 percent more likely to have a child on the spectrum.
Results held up
The researchers also took into account other issues that may be a risk factor for autism, such as parental education, income and smoking habits during pregnancy, and they found that the results held up. As with most research that finds a link between a factor and a result, the researchers stress that it doesn’t prove a causative link, so more studies need to be done.
They also found that boys seemed to be more affected by prenatal pollution exposure than girls, but there were far more boys in the study (279 boys, compared to 46 girls) so explaining the difference between the sexes would need more study.