Study: Autism may be linked to freeways

LOS ANGELES, Dec. 17 (UPI) -- Freeway air pollution has been linked to increased heart attacks and asthma and it may be also linked to autism, U.S. researchers say.

Children ages of 24 and 60 months at the start of the study lived in communities around Los Angeles, San Francisco and Sacramento. The population-based controls were recruited from state of California birth files and were frequency matched to the autism cases by age, gender and broad geographic area.

First author Heather Volk of The Saban Research Institute of Children's Hospital Los Angeles; Dr. Rob McConnell of University of Southern California; Irva Hertz-Picciotto and Lora Delwiche of the University of California at Davis, and Fred Lurmann of Sonoma Technology Inc., examined the locations where the children's families' lived during the first, second and third trimesters of their mothers' pregnancies and freeway proximity.

The study published in the journal Environmental Health Perspectives found that living about 1,000 feet at birth near a freeway was associated with a two-fold increase in autism risk this association was not altered by adjustment for child gender, ethnicity, maximum education in the home, maternal age or prenatal smoking.

Traffic-related air pollutants have been observed to induce inflammation and oxidative stress in toxicological and human studies and there is emerging evidence that this may be involved in the pathogenesis of autism, the study says.