Firs the bad news, then the good news... and then some more bad news... and, finally, what you can do about it.
The bad news: Three new studies found that the children of mother exposed to organophosphate pesticides, including one called chlorpyrifos, a common insecticide, had lower cognitive function at age 7 than children whose mothers weren't exposed. The chlorpyrifos study is out of the Columbia Center for Children's Environmental Health at the Mailman School of Public Health, and all three were published in Environmental Health Perspectives. The researchers compared the level of the pesticide in umbilical cord blood, and the performance of children on standard tests, and found that the more children had been exposed in the womb to the pesticide, the lower their scores on IQ and memory tests. Previous research by the same team had demonstrated similar results for the children at age 3, suggesting that the effects of exposure may continue for years.
Writing for the group's Switchboard blog, NRDC senior scientist Gina Solomon writes:
Scientists are usually too cautious to say they have "proven" anything. Instead, they use terms like "identified an association", "linked", and other cautious science-speak. But three studies published online side-by-side in today's edition of the journal Environmental Health Perspectives come about as close as I can imagine to absolute proof.
The good news: In 2001, the Environmental Protection Agency banned the use of chlorpyrifos in residential settings, where it had previously been one of the most widely used bug killers. Prior to the ban, 70% of cord blood samples and 100% of indoor air samples by Columbia researchers detected the pesticide. Since the ban took effect, researchers have detected a 3-fold decrease in chlorpyrifos levels in indoor air samples, and a more than 5-fold decrease in blood levels.
More bad news: Chlorpyrifos is still used widely on farms that grow food, and it is routinely detected as "pesticide residue" on a range of crops sold widely in the U.S. Whether or not exposure from food residues poses a significant health threat is an open question, but many pregnant women and parents of young children are turning to organic foods grown without the use of pesticides to minimize any risk.
What you can do about it: Below is a list, according to Department of Agriculture testing of foods compiled by the Pesticide Action Network at whatsonmyfood.org, are the foods most likely (greater than 10% chance, based on the latest testing data) to be contaminated with chlorpyrifos (though sometimes at very low levels). These tests are meant to account for the way foods are typically eaten (after being rinsed at home, in other words) so the best way to avoid all exposure is to scrub produce harder... or buy USDA Organic-certified fruits and vegetables.
Apples: 80% of imported and 30% of domestic apple slices tested in 1999, and 18% of imported whole apples tested in 2005 (but less than 1% of domestic whole apples tested that year) had chlorpyrifos residue
Imported sweet bell peppers: 57% of imported peppers, but less than 2% of domestic peppers, tested in 2008 had chlorpyrifos residue
Peaches: 51% of imported peaches (but less than 2% of domestic peaches) tested in 2008, and 45% of imported peach slices and 13% of domestic peach slices tested in 2000 had chlorpyrifos residue
Domestic almonds: 39% of domestic almonds tested in 2008 had chlorpyrifos residue
Plums: 36% of imported plums and 6% of domestic plums tested in 2006 had chlorpyrifos residue
Imported catfish: 31% of imported catfish, but less than 1% of domestic catfish, tested in 2008 had chlorpyrifos residue
Imported nectarines: 30% of imported nectarines (and, oddly, 5% of domestic organic nectarines) tested in 2008 had chlorpyrifos residue
Cranberries: 24% of domestic cranberries tested in 2006 had chlorpyrifos residue
Imported grapes: 23% of imported grapes, but barely 2% of domestic grapes, tested in 2005 had chlorpyrifos residue
Imported spinach: 19% of imported spinach, but less than 3% of domestic spinach, tested in 2008 had chlorpyrifos residue
Domestic corn grain: 18% of domestic corn grain tested in 2008 had chlorpyrifos residue
Domestic soybean grain: 15% of domestic soybean grain tested in 2005 had chlorpyrifos residue
Imported pears: 14% of imported pears, but less than 1% of domestic pears, tested in 2005 had chlorpyrifos residue
Enter your city or zip code to get your local temperature and air quality and find local green food and recycling resources near you.