RESUMO
Autism is a neurodevelopmental disorder that predominantly affects the younger generation. The etiology which contributes to the occurrence of autism is not well defined. However, apart from genetic factors, environmental factors such as metal exposure have been controversial from the last decade. Contamination of several metals was proposed to be responsible for oxidative stress production, mitochondria dysfunction and immune abnormalities which lead to characteristics of autism in children. Objective of review is to analyze the relationship between the most studied toxic metals namely mercury, lead, cadmium and arsenic. Based on the findings, metal toxicity due to lead, mercury and aluminum are clearly exhibited meanwhile insufficient data were available on arsenic and cadmium. In addition, lack of essential minerals in autistic children who were exposed to heavy metals has also precipitated the autistic disorder. However, high quality epidemiological studies with minimal biasness should be conducted to support the correlation of heavy metal with autism.