June 13, 2011 -- Apples again top the "dirty dozen" list of produce most contaminated with pesticides, while onions top the list of the "clean 15."
The rankings come from consumer advocates at the nonprofit Environmental Working Group (EWG), based on pesticide tests from the U.S. Department of Agriculture and the FDA. It updates last year's list with recently released data from 2009 tests.
"Pesticides are toxic," Sonya Lunder, EWG senior analyst, says in a news release. "They are designed to kill things and most are not good for you. The question is, how bad are they?"
It's a good question. A rule of thumb is to avoid exposures that are a thousand times less than levels known to be toxic. A 2009 study led by EPA researcher Devon Payne-Sturges found that about 40% of U.S. children have levels of one type of pesticide well above this 1,000-fold margin of exposure.
Where do kids, and adults, get exposed to pesticides? For most of us, it's through the fruits and vegetables we eat.
The EWG is quick to point out that people should eat more fruits and vegetables, not less -- regardless of the Dirty Dozen report.
"The health benefits of a diet rich in fruits and vegetables outweigh the risks of pesticide exposure," the EWG notes in a news release.
But EWG calculates that by choosing fruits and vegetables from the Clean 15 list instead of the Dirty Dozen list, people can cut their pesticide exposure by 92%.
Even so, nobody is telling anyone to avoid apples, the most pesticide-laden fruit. But EWG recommends choosing organic produce instead of the produce on the Dirty Dozen list. That won't totally cut pesticide exposure, but it could help.
Can you wash pesticides off fruit and vegetables? Yes, it really can help. But the depressing news is that most of the produce was carefully washed before the USDA/FDA tests.
The EWG rating system is based on a score given to each item in six categories:
Percentage of samples with detectable pesticide
Percentage of samples with two or more pesticides
Average number of pesticides found in a single sample
Average amount of all pesticides found
Maximum number of pesticides found in a single sample
Total number of pesticides in the fruit or vegetable
A 2010 study by Harvard researcher Chensheng Lu and colleagues evaluated pesticides in foods eaten by children in two U.S. cities (Atlanta and Seattle). It found that many of the pesticide-containing foods these children ate were on the EWG Dirty Dozen list.