The Environmental Working Group (EWG) has released its 2019 “Dirty Dozen,” highlighting kale as having “higher pesticide residues than nearly all other produce found on supermarket shelves.” EWG releases the list as part of its annual Shopper’s Guide to Pesticides in Produce report, which analyzes USDA test data to identify the produce most and least contaminated with pesticide residues.
On this year’s Dirty Dozen, kale ranks third, after strawberries and spinach. In USDA’s most recent round of tests, more than 92% of conventionally grown kale samples had at least two or more pesticide residues, with some samples containing residues from as many as 18 different pesticides, the report said.
Even as kale’s popularity has soared over the past decade, it hasn’t been included in USDA’s regular produce tests. Kale ranked eighth on the 2009 Dirty Dozen, the last year for which there was testing data.
In the latest tests, almost 60% of the kale samples tested positive for DCPA, or Dacthal, which the EPA has classified as a possible human carcinogen, the report said. The pesticide has been prohibited for use on crops in the European Union since 2009. Recent EWG-commissioned tests of kale from grocery stores found that on two of eight samples, Dacthal residues were comparable to the average level reported by the USDA.
Overall, nearly 70% of the conventionally grown produce sold in the U.S. comes with pesticide residues, EWG’s analysis found. Since 2012, the American Academy of Pediatricians Council on Environmental Health has emphasized that children’s exposure to pesticides should be as limited as possible, because pesticide exposure during pregnancy and early childhood increases the risk of brain tumors, leukemia, neurodevelopmental defects and other adverse birth outcomes.
USDA’s tests found 225 different pesticides and pesticide breakdown products on fruits and vegetables. Before testing, all produce was thoroughly washed and peeled, just as consumers would prepare food at home, showing that simple washing does not remove all pesticides. “Even low levels of pesticide exposure can be harmful to children,” said Pediatrician and Epidemiologist Dr. Philip Landrigan “When possible, parents and caregivers should take steps to lower children’s exposures to pesticides while still feeding them diets rich in healthy fruits and vegetables.” Landrigan is director of the Global Public Health Program and Global Observatory on Pollution and Health at the Schiller Institute for Integrated Science and Society at Boston College. He is a member of the National Academy of Medicine and one of the principal authors of the 1993 National Academy of Sciences study, Pesticides in the Diets of Infants and Children. The study led to enactment of the 1996 Food Quality Protection Act, which emphasized the importance of children’s health in the setting of safety standards for pesticides on foods.
EWG recommends that whenever possible, consumers purchase organic versions of produce on the Dirty Dozen list. But when organic versions are unavailable or not affordable, EWG advises consumers to continue eating fresh produce, even if conventionally grown. “The health benefits of a diet rich in fruits and vegetables outweigh the risks of pesticide exposure,” said EWG Research Analyst Carla Burns.
- More than 90% of samples of strawberries, apples, cherries, spinach, nectarines and kale tested positive for residues of two or more pesticides.
- Kale and spinach samples had, on average, 10% to 80% more pesticide residue by weight than any other crop.
- Avocados and sweet corn were the cleanest. Less than 1% of samples showed any detectable pesticides.
- More than 70% of fruit and vegetable samples on the Clean Fifteen list had no pesticide residues.
- Multiple pesticide residues are extremely rare on Clean Fifteen vegetables. Only 6% of Clean Fifteen fruit and vegetable samples had two or more pesticides.
As in the past, this year EWG has expanded the Dirty Dozen list to highlight hot peppers, which do not meet its traditional ranking criteria but were found to be contaminated with insecticides toxic to the human nervous system.