Several studies have reported a positive association between environmental insults (such as heavy metals exposure) and the increased risk of autism spectrum disorder (ASD) in developed nations. The investigated heavy metals include; aluminum, cadmium, lead and mercury. The prevalence of autism spectrum disorder (ASD) is on the increase in Oman and there was no such studies which have reported about the impact of various environmental factors as a global cause of autism among Omani autistic children.
Objectives:
The present study examined the potential exposure of Omani autistic children to heavy metals toxicity.
Materials and Methods:
A case-control study that included 40 children with ASD and 40 their age and gender matched normal children (control). Hair samples were collected and analysed for aluminum, cadmium, lead and mercury concentrations. The mothers of autistic children were interviewed to report about the exposure of their children to various risk factors such as, vaccinations, exposure to paint, smoking, pesticides use, cooking utensils and seafood consumption.
Results:
ASD children and their age and gender matched controls did not show any detectable differences in the levels of aluminium, cadmium, lead and mercury in the assayed hair samples. It was found that 89% of the ASD children were consuming more than 2 servings of seafood per week versus 53% of control children. There was no socio-demographic or environmental exposure differences between all the children participated in this study.
Conclusions:
Heavy metals exposure was not found to be associated with the increased risk of ASD in Oman. Further studies are however needed to investigate the prenatal and postnatal exposure to heavy metals toxicity and its associated physical symptoms among mothers and their autistic children.