Autism is affecting more and more children. Between 2007 and 2012, the likelihood that a school-age child would be diagnosed with autism, Asperger or a related developmental disorder increased by 72 percent. That increase is partly attributed to simply a rise in awareness of autism spectrum disorders. But the question remains: what’s causing autism?
There is no known cause of autism, but there has been ongoing concern over the link between the developmental disorder and toxins, specifically as it relates to prenatal exposure. A new study from UC Davis adds to that growing concern, showing that pregnant women who live in proximity to agricultural fields where pesticides are used are at higher risk of having a child with autism.
The researchers took data from the California Pesticide Use Report, which shows what pesticides are used and where, and overlaid it with addresses of about 1,000 participants in a Childhood Autism Risks from Genetics and Environment study, “a population-based, case-control study of children ages 2-5 with autism, developmental delay and typical development,” according to the Fresno Bee. The study area was primarily around the Sacramento area, a region rich with agriculture.
The researchers specifically looked at four groups of pesticides: organophosphates, organochlorines, pyrethroids and carbamates. These are common pesticides in the Sacramento Valley, used for agricultural production like cantaloupe, melon, oranges, tomato processing, cotton and alfalfa.
Analyzing the data, the researchers established that about one-third of the mothers in the study lived within just under a mile of an agricultural pesticide application when they were pregnant, and the farther the pregnant women lived from where pesticides were sprayed, the more the risk for autism decreased.
On days when pesticides are being applied, parents may want “to leave town or keep their children away or close the windows,” Dr. Irva Hertz-Picciotto, senior author of the report and professor and vice chair of the Department of Public Health Services at UC Davis, told the Fresno Bee.
This isn’t the first study of its kind in California. In 2007, a study “found children born to mothers who had been exposed to two organochlorine pesticides during their first trimester of pregnancy were six times more likely to develop autism than a control group whose mothers did not live near fields.”
While there is currently no known cause of autism, “a large number of widely used agricultural pesticides have known neurologic effects,” said the study, making more research on the connection between pesticides and autism even more important.
Photo Credit: benketaro