This article is more than 5 years old. Information may no longer be current.

Prenatal, postnatal exposure to fine particulate matter increases risk for autism

Prenatal and postnatal exposure to fine particulate matter increased risk for autism spectrum disorder, according to study findings in Environmental Research.

“Several recent studies have focused on the association between exposure to air pollution (traffic related and from industry) and autism,” study researcher Evelyn O. Talbott, PhD, of the University of Pittsburgh Graduate School of Public Health, and colleagues wrote. “Although the time periods of the investigations, timing of the exposure periods and exposure assessments themselves are varied, the results of these studies suggest a potential role for air pollution, including [fine particulate matter] in the development of autism.”

Evelyn O. Talbott

To examine the association between autism spectrum disorder (ASD) and exposure to fine particulate matter (PM_2.5), researchers assessed 217 children with ASD and 226 healthy controls born between January 2005 and December 2009 in southwestern Pennsylvania. Mothers were interviewed to determine demographic and socioeconomic information, maternal and paternal occupation history, family history of ASD, smoking history, maternal reproductive and pregnancy history, child’s medical history and residential history. A land use regression model was used to determine person- and time-specific PM_2.5 estimates for individual (pre-pregnancy, pregnancy, first 2 years of life) and cumulative developmental periods.

In an unadjusted analysis, an increase of 2.84 μg/m³ in average exposure to PM_2.5 prior to pregnancy through the first 2 years of the child’s life increased risk for ASD by approximately 50% (OR = 1.46; 95% CI, 0.99-2.15; P = .057).

This association was also found when adjusting for maternal college education, smoking, race and age, (adjusted OR = 1.51; 95% CI, 1.01-2.26; P = .046).

Effect estimates for PM_2.5 were high but not statistically significant for individual pregnancy periods (3 trimesters) or for total pregnancy alone, suggesting the importance of maternal exposure prior to pregnancy.

“Our data indicates that both prenatal and postnatal exposure to PM_2.5 play a role in incurring increased risk of ASD. From a historical perspective, air pollution levels have been declining since the 1990s; however, we know from our research that pockets of increased levels of air toxicants remain throughout our region and others,” Talbott and colleagues wrote. – by Amanda Oldt

Disclosure: The researchers report no relevant financial disclosures.