The role of mercury in the occurrence of autism spectrum disorder (ASD): A case-control study on Syrian children

Abstract

Background: Autism spectrum disorder (ASD) is a disorder that affects social movement and language communication and is diagnosed during childhood. Although the cause of autism is still not fully understood, many researches indicated that there are genetic and environmental factors that contribute to the occurrence of this disorder. One theory that has been raised is the relationship between ASD and mercury exposure levels. Therefore, due to the increase in heavy metals pollution in Syria, and the negative impact on public health, this research aimed to measure blood mercury concentrations in Syrian children diagnosed with autism spectrum disorder, their siblings, and unrelated controls.

Materials And Methods: The study included 30 children diagnosed with autism spectrum disorder, and 30 control children, divided into 15 children who were siblings of the patients and 15 control children. Mercury was extracted from whole blood and measured using graphite furnace atomic absorption spectrometry (GFAAS)

Results: Mercury concentrations ranged between 51.6 and 1926.2 ng/ml in children with ASD, between 72 and 1984.8 ng/ml in siblings, and between 40.8 and 1707.2 in non-sibling controls. Statistical analysis showed a significant difference between mercury concentrations in children and siblings compared to controls, and in female children compared to males. However, there was no significant difference between ASD and siblings’ children.

Conclusions: This study raises questions about the causal relationship between mercury exposure and the development of autism spectrum disorder. More studies are still needed to determine the extent of the influence of environmental exposure in comparison to to genetic factors.