Brain scans of a group of adolescents in California’s Salinas Valley show a direct link between reductions in certain brain functions and the level of pesticides their mothers were exposed to during pregnancy.
This research, by scientists at Stanford and UC-Berkeley, adds to existing data about the health effects of insecticides used on the abundance of lettuce, strawberries, broccoli, spinach and other produce grown in the Salinas area.
Though the federal Environmental Protection Agency has banned some organophosphate pesticides and the California EPA recently expanded prohibitions, many are still used in farming. Most people ingest pesticides through food, while farming community residents are exposed through field dust.
Stanford researchers scanned the brains of 95 adolescents who grew up in Salinas and whose mothers lived there during pregnancy. The Berkeley team began following the children in 1999, using data about where the mothers lived to estimate levels of pesticide exposure in utero.
Scans were taken as children completed tasks that measured brain function. When tasks required such skills as strategic planning or modulating impulses, scans revealed lower brain activation in children with more prenatal pesticide exposure.
“It’s really quite amazing that we see a long-term association between these exposures and brain function,” said neuroscientist Allan Reiss, MD, who co-authored the study with experimental psychologist Joseph Baker, PhD. They hope their findings, published Sept. 10 in Proceedings of the National Academy of Sciences, spark further research and more conversation about pesticide use trade-offs.