Adecade-long study of women farm workers in Salinas, published earlier this year in the journal Pediatrics, shows a link between pesticide exposure and attention deficit hyperactivity disorder in their children.

“When we started,” Field Study Coordinator Celina Trujillo says, “there were no data as to levels of pesticides in pregnant women and their children in agricultural communities.”

Trujillo, who works with the Salinas-based Center for the Health Assessment of Mothers and Children of Salinas, says her group conducted the investigation in partnership with UC Berkeley.

The researchers recruited 600 pregnant women at local clinics and found significantly elevated pesticide levels in their blood, Trujillo says. They’ve followed the women and their children ever since, zeroing in organophosphates commonly used in the Salinas Valley on lettuce, broccoli and celery, and almost every other locally grown crop.

Organophosphates were first developed for chemical warfare because they are toxic to the nervous system.

Kids with higher blood levels of the pesticide were more likely to show signs of ADHD than those with lower levels, as measured by interviews with the moms and a computerized test that measures a child’s ability to focus.

“It was a good study,” says Monterey County’s Assistant Agricultural Commissioner Bob Roach, adding that state and federal regulators should take note. Still, Roach notes that the study didn’t determine what accounted for elevated pesticide levels in the participating women and kids.

Indeed, Trujillo points out that even though the women work in pesticide-laden fields, it’s tough to pin down exactly how much exposure the women got at work and how much they encountered at home, where many live close to agricultural areas, or even from over-the-counter bug sprays and the food they eat.

Reducing exposure is a huge concern, Trujillo says. Her group offers a long list of recommendations, including changing shoes and clothes, if possible, when farm workers get in the car after work, thoroughly washing fruits and vegetables, bringing kids and pets inside while nearby fields are sprayed, and closing doors and windows.

Next up for CHAMACOS is another look at the neurological development of the kids in the study, who are now 10 years old.