Study finds autistic children show similar blood mercury levels to typically developing children
TUESDAY, Oct. 20 (HealthDay News) -- Blood mercury levels are similar in children with autism or autism spectrum disorder (AU/ASD), non-autism developmental delays (DD) or typically developing (TD) controls, according to the Childhood Autism Risk from Genetics and the Environment study published online Oct. 19 in Environmental Health Perspectives.
Irva Hertz-Picciotto, Ph.D., of the University of California in Davis, and colleagues evaluated 452 children aged 2 to 5 years, of whom 249 had AU/ASD, 60 had non-autistic DD, and 143 were TD controls. The researchers interviewed mothers to ascertain the children's household, medical, and dietary exposure to mercury.
After adjusting for fish consumption, the researchers found that those with AU/ASD had similar blood mercury levels to those of TD children. In addition, children who had mercury dental amalgams and who chewed gum or ground their teeth had higher blood mercury levels, while non-autistic DD children had lower blood mercury concentrations than the other two groups.
"Children aged 2 to 5 years with autism or other ASD had similar blood mercury concentrations to TD controls after adjustment for a variety of home and medical mercury sources," the authors conclude. "This finding was maintained when analysis was restricted to non-fish eaters. Blood mercury levels in both controls and cases were very close to those of a nationally representative sample of 1 to 5 year olds in the United States."