Spinach, strawberries top new U.S. ‘Dirty Dozen’ list of pesticide-laden produce

Strawberries placed second on the Environmental Working Group's "Dirty Dozen" list this year. (golibo/iStockphoto/Getty Images via CNN Newsource)

More than 90 per cent of samples of a dozen fruits and vegetables tested positive for potentially harmful pesticide residues, according to the 2025 Shopper’s Guide to Pesticides in Produce.

Dubbed the “Dirty Dozen,” the list is compiled from the latest government testing data on non-organic produce by the Environmental Working Group, or EWG, a health advocacy organization that has produced the annual report since 2004.

Spinach topped the list, with more pesticide residue by weight than any other produce tested, followed by strawberries, kale (along with mustard greens and collards), grapes, peaches, cherries, nectarines, pears, apples, blackberries, blueberries and potatoes.

The annual report is not meant to discourage consumers from eating fruits and vegetables, which are key to good health, but instead to provide tools for decisions on whether to buy organic for the fruits or vegetables their families consume the most, said Alexis Temkin, EWG’s vice president of science.

“The guide is there to help consumers eat a lot of fruits and vegetables while trying to reduce pesticide exposure,” Temkin said. “One of the things that a lot of peer-reviewed studies have shown over and over again (is) that when people switch to an organic diet from a conventional diet, you can really see measurable levels in the reduction of pesticide levels in the urine.”

The Alliance for Food and Farming, which represents organic and conventional produce farmers, has been a long-standing critic of the annual report.

“We strongly support consumer choice when shopping for fruits and vegetables. But this choice should not be influenced by this list,” Teresa Thorne, the alliance’s executive director, said in an email.

“Instead consumers should be reassured by decades of toxicology studies, government data and nutrition research which underscores the importance of a diet rich in fruits and vegetables on health and the safety of both organic and conventionally grown produce,” Thorne added.

New to the list: Blackberries and potatoes

Blackberries were new to the list, having never been tested before by the U.S. Department of Agriculture, while potatoes joined the rankings after being absent in recent years — mainly due to the use of a plant growth regulator called chlorpropham. The chemical has been banned in the European Union, Temkin said.

“It’s applied after harvest to essentially prevent potatoes from sprouting while they’re in storage or in transit,” Temkin said. “Because it’s applied so late after harvest and so close to when consumers might be exposed or eating potatoes, that’s partially what leads to some of these really high concentrations.”

More than 50 different pesticides were detected on each of several crops on the Dirty Dozen section of the Shopper’s Guide, which was updated this year to measure pesticide toxicity, Temkin said.

“We still have measurements of the detection frequency of pesticides, how many different pesticides are found on produce, as well as the overall concentration. We also have an indicator of that concentration relative to a dose that might cause harm in an animal study,” she said.

“A lot of the Dirty Dozen produce rank really highly when you look at pesticide toxicity, especially relative to the ‘Clean Fifteen’ items, which have fewer detections of pesticide residues,” Temkin added.

This year’s ‘Clean Fifteen’

As part of the report, EWG also creates an annual “Clean Fifteen” — a list of conventional produce with the least amount of pesticide residue. Many of these fruits and vegetables are protected by skins you peel before eating — but not all.

Pineapple was the least contaminated produce tested, followed by sweet corn (fresh and frozen), avocados, papaya, onions, frozen sweet peas, asparagus, cabbage, watermelon, cauliflower, bananas, mangos, carrots, mushrooms and kiwi.

“An important aspect of the USDA pesticide testing is they really try to mimic consumer behavior. … They wash fruits or vegetables for about 15 or 20 seconds under running water, and then they also peel something like citrus or a mango or a banana,” Temkin said.

“If there are any pesticides on that outer layer, that is removed, and that might be one of the reasons why some of these fruits or vegetables that are on the Clean Fifteen tend to have less detectable pesticide residues.”

How to clean produce

More tips: All produce, even organic, should be washed before peeling so dirt and bacteria aren’t transferred from a knife onto the fruit or vegetable, according to the U.S. Food and Drug Administration. After washing, dry with a clean cloth or paper towel.

Firm produce such as carrots, cucumbers, melons and potatoes can be scrubbed with a clean vegetable brush under running water, the FDA said. All other produce can be gently rubbed while being rinsed. There’s no need to use bleach, soap or a produce wash — fruits and vegetables are porous and can absorb the chemicals.

Remove the outermost leaves of cabbage, lettuce and other leafy greens and rinse each leaf carefully — but don’t blast your greens with water, or you’ll bruise them. Experts said it’s best to use low-pressure water that is warmer than your produce and a colander to spin the greens dry. Don’t forget to wash the colander afterward.

Exceptions are “triple-washed” bagged greens, which the FDA said do not need an additional wash.

Dangers of pesticides

Pesticides have been linked in studies to premature births, congenital malformations such as neural tube defects, spontaneous abortions and an increase in genetic damage in humans. Exposure to pesticides has also been associated with lower sperm concentrations, heart disease, cancer and other disorders.

Farmworkers who use or are exposed to pesticides are at highest risk, according to studies. A 2022 meta-analysis found workers exposed to pesticides were nearly five times as likely to have DNA damage, while a February 2024 study concluded children exposed at an early age showed poorer neurodevelopment from infancy to adolescence.

Children are the most susceptible to the dangers of pesticides due to their small size and developing body and brain, experts say. The risk can actually begin in the womb.

“Pesticide exposure during pregnancy may lead to an increased risk of birth defects, low birth weight, and fetal death,” according to the American Academy of Pediatrics. “Exposure in childhood has been linked to attention and learning problems, as well as cancer.”

By Sandee LaMotte, CNN