RODALE NEWS, EMMAUS, PA—Autism is more prevalent in counties that receive more rain and snow, according to an analysis of data from the states of California, Oregon, and Washington published in this month’s Archives of Pediatrics and Adolescent Medicine. Autism affects an estimated 1 in 150 children today. And although nobody knows what causes it, some believe environmental triggers could spark the condition in children already genetically wired for the disorder. The study authors suggest rain could drive children indoors, which could mean more TV watching, more exposure to indoor air pollution, or vitamin D deficiency.
THE DETAILS: Cornell University researchers studied weather data from counties in California, Oregon, and Washington, and mapped it to the number of school-age children with autism. They found more cases of autism in the rainy parts of California and the wet climates of western Oregon and Washington, compared with the drier counties. If precipitation could be removed from the equation—somehow—they estimate more than 40% of autism cases might be eliminated.
On the other hand, the phenomenon may have more to do with doctors than patients, as Noel Weiss, PhD, professor of epidemiology at the University of Washington in Seattle, points out in an editorial appearing in the same edition of the journal. Diagnosing autism is tricky, he says, and concentrations of medical centers in rainy areas of the states could mean more autism cases are reported in these areas. “The rainy, western part has more medical centers compared to the drier, eastern side,” says Weiss. He also notes the information is published for other researchers, and fears the media and general public will misinterpret it.
WHAT IT MEANS: This study can be used by medical researchers as a small clue in the autism puzzle, and could spark more research regarding specific environmental triggers and autism. But it is by no means definitive evidence that higher precipitation levels and autism are connected. “There is no cause for alarm,” says Weiss. “Just stay tuned. There is nothing anyone from the general population should take from this.” He adds that the chances of actual proof coming out of a rain-autism connection are small.
Want to take sensible precautions while the experts investigate the rainfall-autism relationship? Consider these tips: