Autism Spectrum Disorders in Relation to Distribution of Hazardous Air Pollutants in the some areas. http://www.ehponline.org/members/2006/9120/9120.html 1Division of Environmental and Occupational Disease Control, California Department of Health Services, Richmond, California, USA; 2Impact Assessment, Inc., La Jolla, California, USA; 3Kaiser Permanente Medical Care Program Division of Research, Oakland, California, USA Abstract Objective: To explore possible associations between autism spectrum disorders (ASD) and environmental exposures, we linked the California autism surveillance system to estimated hazardous air pollutant (HAP) concentrations compiled by the U.S. Environmental Protection Agency. Methods: Subjects included 284 children with ASD and 657 controls, born in 1994 in the San Francisco Bay area. We assigned exposure level by census tract of birth residence for 19 chemicals we identified as potential neurotoxicants, developmental toxicants, and/or endo...