Once a relatively obscure disorder, autism has become increasingly common. In the last four decades, the incidence of autism has increased ten-fold, and according to the Center for Disease Control and Prevention, 1% of all eight-year-old children now have some form of the condition.
Autism is not a single ailment, but a spectrum of disorders characterized by varying levels of emotional and cognitive impairment, social and communication deficits, and motor difficulties. Autism symptoms can range from near complete withdrawal to a mild inability to read and respond appropriately to social cues.
An inherited predisposition to autism appears to play a role in its development, yet genetics alone are responsible only for about 25% of all cases. What’s causing the rest remains a scientific mystery, but growing numbers of experts believe environmental influences are responsible, specifically prenatal exposure to chemical toxins during critical windows of neurological development.
Researchers at the University of Southern California, for example, found that exposure to air pollutants combined with a genetic risk increases the likelihood of autism. Other studies have found a connection between autism symptoms and in utero exposures to thalidomide, misoprostol, valproic acid, the insecticide chlorpyrifos, and phthalates. (To date, no credible evidence links childhood vaccinations to the disorder.)
Research exploring possible environmental causes of autism is currently underway. Scientists at the University of California, Davis, for example, are now studying over 1,800 children in an attempt to identify toxins that may contribute to the condition. And the Mount Sinai Children’s Environmental Health Center has created a list of 10 priority toxin categories that available evidence suggests may contribute to autism: lead, methylmercury, PCBs, organochlorine and organophosphate pesticides, endocrine disruptors, automobile exhaust, polycyclic aromatic hydrocarbons, brominated flame retardants, and perfluorinated chemicals.
Since most evidence points to autism’s development in the womb, until more is known, pregnant women and those who may become pregnant should seek to avoid as many environmental toxins as possible. Suggested lifestyle changes include adopting an organic diet based on fruits and vegetables, and removing common sources of toxins from the home. To learn more about these and other precautionary actions, explore Healthy Child Healthy World’s many Easy Steps.
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