Blueberries back on the Dirty Dozen™, with traces of several toxic pesticides

WEDNESDAY, MARCH 15, 2023

Americans are eating three times as many blueberries as they did in the early 2000s. But this popular fruit is also part of a worrying trend – an increase in pesticide residues, leading to blueberries’ return this year to EWG’s Dirty Dozen™, showing up in 11th place.

Our list is based on an analysis of Department of Agriculture data, which tests some fruit samples in certain years. Compared to the last time blueberries were tested, in 2014, more samples had detectable residues. Tests of 765 non-organic blueberry samples collected in 2020 and 2021 found more than 90 percent had pesticide residues, up from 81 percent with detectable residues in 2014.

There were other worrying findings:

• Just under 80 percent of samples had two or more pesticides, compared to 70 percent in 2014.
• A sample of blueberries had up to 17 different pesticide residues, compared to 13 in 2014.

The most troubling pesticides are phosmet and malathion, chemicals known as organophosphate insecticides. They kill many types of insects and are toxic to the human nervous system, especially children’s developing brains. Phosmet was detected on more than 10 percent of blueberry samples, with malathion close behind at 9 percent.

Phosmet is not approved for use in the European Union, and malathion is approved for use in greenhouses only. Yet the Environmental Protection Agency currently allows both for use on U.S. crops, putting blueberry fans at potential risk.

And that’s a problem, because children between the ages of two and five are especially fond of berries, which account for over 5 percent of the total amount of fruit they eat.

The EPA’s most recent assessment of phosmet said the chemical shows up at levels of concern in the diets of infants and young children, and blueberries were a major contributor to the estimated exposure. Other Dirty Dozen fruits, including grapes, apples, pears and peaches, also play a role.

Malathion was classified by the International Agency for Research on Cancer, in 2015, as probably carcinogenic to humans.

The USDA’s latest blueberry test results justify adding this fruit to the Dirty Dozen. The results also show that phosmet and malathion are detected less frequently on blueberries now than in 2014.

But other concerning pesticides are also often found on blueberries:

• Boscalid, a fungicide the EPA classifies as having suggestive evidence of carcinogenic potential, was found on nearly half the blueberries tested, compared to 40 percent in 2014.
• Detections of neonic insecticides have gone up. Acetamiprid and imidacloprid were found on 36 and 12 percent of samples, compared to 11 and 7 percent in 2014. The pyrethroid insecticides cypermethrin and bifenthrin were found on 23 and 16 percent of samples, compared to 21 and 8 percent in 2014. These insecticides are less toxic than the organophosphates they replaced, but recent studies suggest they may also be harmful to children’s health.

Detections of the fungicides cyprodinil, azoxystrobin and fludioxonil have gone up. They were found on 34, 30 and 28 percent of samples, compared to 29, 19 and 17 percent, respectively, in 2014. The safety of long-term human exposures to these fungicides has not been proven.