Study links common pesticides on food to ADHD in kids
Exposure is nearly ubiquitous, children with higher levels of exposure are nearly twice as likely to have ADHD
SAN FRANCISCO, CA - A new study out of Montreal and Harvard shows that even tiny, allowable amounts of a common pesticide class can have dramatic effects on brain chemistry. Organophosphate insecticides (OP's) are among the most widely used pesticides in the U.S. They work by interfering with brain signaling in insects. Initially developed as chemical warfare agents during World War II, slightly less toxic versions of this chemical class were later brought to market as agricultural insecticides.
OPs have long been understood to be particularly toxic for children, but this is the first study to examine their effects across a representative population with average levels of exposure. Children are at particular risk for two reasons: they are exposed to higher levels of chemicals, and their bodies are biochemically less adept at detoxification.
Dr. Susan Kegley, consulting scientist with Pesticide Action Network North America explains: "When it comes to pesticides, children are among the most vulnerable -- pound for pound, they drink 2.5 times more water, eat 3-4 times more food, and breathe twice as much air as adults. They also face exposure in the womb and via breast milk. Add to this the fact that children are unable to detoxify some chemicals and you begin to understand just how vulnerable early childhood development is."
94% of children tested in the study showed detectable levels of OP pesticide metabolites in their urine. Of these, children with the highest levels had higher likelihood of being diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD). The study was designed to get an accurate picture of the average child's exposure and risk scenario. Where previous studies looked primarily at populations like farmworkers, who face especially high exposure rates, this one is based on a representative sample of the U.S. population taken from the government's National Health and Nutrition Examination Survey.
OPs are the most widely used class of insecticides in the U.S. They are also among the most acutely toxic. "We've known for a long time that they poison farmworkers at higher doses, now we have a window into their lower-dose effects on the broader population," comments Kegley.
"Buying organics helps to reduce exposure - especially in critical developmental windows; but we can't really shop our way out of this," according to Dr. Margaret Reeves, senior scientist at Pesticide Action Network North America. "This is a public health issue, and a good governance issue - not a consumer choice issue. By saying the solution here is to 'buy organic' we are, in effect, saying that people on a tight food budget have no right to feed their children safe food and that farmworkers have no right to a non-toxic workplace. We know how to farm without OPs, but farmers need us as citizens to support policy approaches that will fund the shift to sustainable farming and safe food production. What this study indicates is that our children need a safe and sustainable food system most of all."
According to the University of California' California Agriculture journal, less-toxic alternatives to OP's include the use of: (1) pheromones -- chemicals secreted by insects for communication -- to disrupt insect mating; (2) cultural controls like using crop rotations, manipulating planting dates, reducing of pest habitats and improving crop vigor; and (3) less toxic, more pest-specific alternative insecticides.