As the rate of diagnosed cases of autism has increased, to roughly 1 in 150 children, parents and researchers have searched for the reason. The mercury preservative in vaccines was long suspected, and was removed from childhood vaccines despite official pronouncements that it is safe. Chemicals in the environment, like pesticides, have been fingered as suspects, as have doctors who may just be diagnosing more of a disease that's always been out there.
Today, scientists make an almost unbelievable claim: The more rain a community receives, the higher its rate of autism.
Could rain actually cause autism? Other hypotheses have generally focused on the way chemicals might interrupt the normal development of the brain, either in utero or early in a child's life.
The new study, published in the Archives of Pediatrics & Adolescent Medicine, shows that West Coast counties that get more rain each year have higher rates of autism in school age children, and children who experienced a lot of rain before the age of 3 appeared more prone, statistically, to developing autism.
It may be that rain washes something out of the upper atmosphere that can trigger autism, the author said. Or it may be that rain forces kids to spend more time indoors, where there are chemicals that may trigger disease are more concentrated (indoor air quality is often worse than air quality outdoors). It may be that more time indoors means more time watching television, which could affect development. Or it may be that these kids growing up in rainy counties just don't get enough exposure to sunlight, and the Vitamin D it provides.
In other words, the study raises more questions than it answers. That prompted the author of an editorial accompanying the study in the peer-reviewed journal to caution: "No call for alarm, stay tuned."
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