Mercury Exposure in Children With Autistic Spectrum Disorder: Case-Control Study

Abstract

Although mercury has been proven to be a neurotoxicant, there is a lack of data to evaluate the causal relationship between mercury and autism. We aim to see if there is increased mercury exposure in children with autistic spectrum disorder. We performed a cross-sectional cohort study over a 5-month period in 2000 to compare the hair and blood mercury levels of children with autistic spectrum disorder ( n = 82; mean age 7.2 years) and a control group of normal children ( n = 55; mean age 7.8 years). There was no difference in the mean mercury levels. The mean blood mercury levels of the autistic and control groups were 19.53 and 17.68 nmol/L, respectively ( P = .15), and the mean hair mercury levels of the autistic and control groups were 2.26 and 2.07 ppm, respectively ( P = .79). Thus, the results from our cohort study with similar environmental mercury exposure indicate that there is no causal relationship between mercury as an environmental neurotoxin and autism. ( J Child Neurol 2004;19:431-434).