Study: Conventional strawberries most contaminated with pesticides

Conventional strawberries top the Dirty Dozen list from the Environmental Working Group’s 2016 Shopper’s Guide to Pesticides in Produce.

For the past five years, apples had topped the list.

Nearly all strawberry samples — 98 percent — tested by federal officials had detectable pesticide residues, according to EWG.

Forty percent had residues of 10 or more pesticides and some had residues of 17 different pesticides. Some of the chemicals detected on strawberries are relatively benign but others are linked to cancer, reproductive and developmental damage, hormone disruption and neurological problems.

Strawberries were once a seasonal, limited crop, but heavy use of pesticides increased yields and stretched the growing season. In California, where most U.S. strawberries are grown, one acre can be treated with about 300 pounds of pesticides. More than 60 pounds are conventional chemicals that may leave post-harvest residues but most are fumigants — volatile poison gases that can drift into nearby schools and neighborhoods, according to EWG.

“It is startling to see how heavily strawberries are contaminated with residues of hazardous pesticides, but even more shocking is that these residues don’t violate the weak U.S. laws and regulations on pesticides in food,” said Sonya Lunder, EWG senior analyst. “The EPA’s levels of residues allowed on produce are too lax to protect Americans’ health. They should be updated to reflect new research that shows even very small doses of toxic chemicals can be harmful, particularly for young children.”

Recent studies of insecticides used on some fruits and vegetables, including strawberries, found children exposed to high levels were at greater risk of impaired intelligence and ADHD. Research also indicates the levels of pesticides in the bodies of elementary school children peaked during the summer, when they ate the most fresh produce. But after just five days on an organic diet, they were essentially pesticide-free.

The Dirty Dozen lists the fruits and vegetables that have been contaminated by multiple pesticides and which have higher concentrations of pesticides.

More than 98 percent of strawberries, peaches, nectarines and apples tested positive for at least one pesticide residue. The average potato had more pesticides by weight than any other produce.

Clean 15

Avocados, on the other hand, remained on the group’s Clean 15 list, with less than 1 percent of samples showing any detectable pesticides. No single fruit sample from the Clean 15 tested positive for more than four types of pesticides and very few for more than one.

The Shopper’s Guide to Pesticides in Produce, updated every year since 2004, ranks pesticide contamination on 48 popular fruits and vegetables. EWG’s analysis is based on results of more than 35,200 samples tested by the U.S. Department of Agriculture and Food and Drug Administration. This year’s update found a total of 146 pesticides on fruit and vegetable samples tested in 2014 – residues that remain on produce even after items are washed and in some cases peeled.