Autism Research Review International
Volume 19, No. 1, 2005

A new study suggests that higher levels of environmental mercury from industrial plants are correlated with rising rates of autism.

Raymond Palmer and colleagues used data from the Environmental Protection Agency to analyze county-by-county levels of mercury emissions as reported to the EPA by industrial facilities in Texas. They then used statistics from the Texas Education Agency to determine the rates of autism and special education services reported by school districts in 254 counties in the state, controlling for multiple economic and demographic factors.

Palmer et al, report, "On average, for each 1,000 pounds of environmentally released mercury, there was a 43 percent increase in the rate of special education services and a 61 percent increase in the rate of autism." When the researchers controlled for total autism counts, the link between mercury and special education rates was no longer statistically significant, indicating that "the association between mercury release and school district special education rates was completely accounted for by increased rates of autism".

Commenting on the study, Isaac Pessah of the UC Davis MIND Institute told the Los Angeles Times, "It's rather intriguing that the correlation is so positive….It makes one worry". Palmer et al, conclude that their study "supports prior recommendations for reducing environmentally released mercury".

"Environmental mercury release, special education rates, and autism disorder; an ecological study of Texas", Raymond F. Palmer, Steven Blanchard, Zachary Stein, David Mandell, and Claudia Miller, Health and Place (in press). Address: Raymond F. Palmer, University of Texas Health Science Center, San Antonio Department of Family and Community Medicine, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, palmerr@uthscsa.edu.

"Possible mercury, autism connection found in study", Thomas H. Maugh II, Los Angeles Times, March 2005.

"Mercury, autism link in Texas", Reuters, March 17, 2005