Blood levels of mercury and lead are much higher in autistic children as compared to normal controls.
Autism: A form of lead and mercury toxicity
Yassa HA. Environmental Toxicology and Pharmacology. 2014;38:1016-1024.
The aim of this study was to find out the relation between exposure to lead and/or mercury as heavy metals and autistic symptoms and assess use of chelating agents for dealing with heavy metals and improving autistic symptoms. The results showed significantly higher levels of mercury and lead among children with autism compared to children without autism, and a significant decline in the blood levels of lead and mercury with the use of DMSA as a chelating agent. In addition, there was a decline in autistic symptoms with the decrease in the lead and mercury levels in blood.