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March 17, 2021 -- Strawberries, spinach, and kale top this year's "Dirty Dozen" list, released annually by the Environmental Working Group as a shopper's guide to avoid pesticide in produce.

All three items were in the same positions last year, but the 2021 version also adds collard and mustard greens along with kale in the No. 3 spot. Nearly 70% of the non-organic fresh produce sold in the U.S. has residues of potentially harmful pesticides, the latest report found.

There's also the usual "Clean 15" list, produce with the lowest amounts of pesticide residue. This year, as last, avocados, sweet corn, and pineapple grabbed the top three spots. This year, EWG, a nonprofit organization focused on human health and the environment, also calls out harmful fungicides found on citrus fruits.

The list, which has been issued annually since 2004, is receiving the same criticism this year as in past years. Experts say the report raises unfounded food safety fears and may result in consumers passing up fruits and vegetables, which have substantial health benefits.

Discouraging people from eating produce is not the goal, says Thomas Galligan, PhD, an EWG toxicologist. "We want to emphasize that eating lots of fruits and vegetables is part of a healthy diet," he says. "We also think people should reduce their pesticide exposures."

One way to do that is to buy organic produce, "but not everyone has access, so that's why we produce our 'Clean 15' list," with fruits and vegetables found with lower pesticide residues. The EWG analysis is based on test data from the U.S. Department of Agriculture and the FDA.

2021's Dirty Dozen

This year's complete list of produce found with the most pesticide residue includes:

1. Strawberries

2. Spinach

3. Kale, collard, and mustard greens

4. Nectarines

5. Apples

6. Grapes

7. Cherries

8. Peaches

9. Pears

10. Bell and hot peppers

11. Tomatoes

12. Celery

2021's Clean 15

Making this list:

1. Avocados

2. Sweet corn

3. Pineapple

4. Onions

5. Papaya

6. Sweet peas (frozen)

7. Eggplant

8. Asparagus

9. Broccoli

10. Cabbage

11. Kiwi

12. Cauliflower

13. Mushrooms

14. Honeydew melon

15. Cantaloupes

Fungicides on Citrus

Two fungicides found on citrus fruits are another concern, EWG says. Imazalil, a fungicide that the Environmental Protection Agency says likely causes cancer, was found on almost 90% of samples tested by EWG in 2020 and more than 95% of tangerine samples tested by the USDA in 2019. Another, thiabendazole, was also found on nearly 90% of non-organic produce samples. Both are also potential hormone disrupters, capable of altering the endocrine system, EWG says.

More Findings, Research Methods, Health Concerns

Of the 46 items included in the EWG analysis, the fruits and vegetables on the "Dirty Dozen" list were found to have more pesticide residue than other crops. The EWG researchers considered the percentage of samples with pesticides, but also the number and amount of pesticides on all samples as well as on individual samples.

More than 90% of the samples of strawberries, apples, cherries, spinach, nectarines, and leafy greens were positive for residues of two or more pesticides. Hot peppers and bell peppers were found to have the most pesticides, with 115 in total. On the collard, mustard green, and kale samples, the most common pesticide found was DCPA, or Dacthal. The EPA classifies it as a possible human carcinogen.

On the "Clean 15" list, fewer than 2% of the avocado and sweet corn samples showed any detectable pesticides. Almost 70% of the 15 fruit and vegetable samples on the list had no pesticide residues.

The rankings are based on EWG's analysis of more than 46,000 samples taken by the USDA and the FDA. The USDA picks a subset of produce to test each year, in lieu of testing every crop every year.

Perspective From a Toxicologist

"In compiling the Dirty Dozen list, the EWG ignores the three key determinants of risk -- the toxicity of the pesticides, the amounts of the pesticides found, and the amount of the food consumed," says Carl K. Winter, PhD, a cooperative extension specialist emeritus at the University of California, Davis. "When accounting for such factors, our typical exposure to pesticides in foods is far below the level of health concern. Consumers should be encouraged to consume more fruits and vegetables instead of being told which ones they should fear."

In a previous analysis of an EWG "Dirty Dozen" list, Winter concluded that the exposures to the most common pesticides "pose negligible risk to consumers," that substituting organic produce doesn't result in any appreciable cut in risk, and that the methodology to rank the produce by risk "lacks scientific credibility."

Input from a Dietitian

Connie Diekman, a registered dietitian in St. Louis and former president of the Academy of Nutrition and Dietetics, encourages people to aim to eat the amount of produce recommended in the 2020-2025 Dietary Guidelines. The guidelines’ advice is to make half of your plate fruits and vegetables and to eat about 2½ cups of vegetables and 2 cups of fruit daily.

"The EPA and USDA work very hard to check our food supply for safety, and they provide guidance on how we should consume foods that are enjoyable, nutritious, and safe," she says. "Their guidance also extends to what pesticides can be used in food production, how much can be used, and how much can remain on food. If we choose a variety of fruits and vegetables, so [there is] no excess of a single product, we should feel comfortable with the safety of food. The most important reminder about fruits and vegetables is that they provide a wide variety of nutrients and should be a part of our daily diet."

She understands that some people prefer organic. But some people don't wish to pay extra for organic, or can't, and they should remember that "our produce is safe and essential for health."

Produce Industry's Take

The "Dirty Dozen" list moves consumers away "from buying any produce, organic or conventional," says Teresa Thorne, executive director of Alliance for Food and Farming, an industry group representing conventional and organic growers. She cites a previous study finding that low-income shoppers, if informed about pesticides on specific produce, would be less likely to buy any produce, conventional or organic.

She took issue with the information on fungicide on citrus. "So many people are enjoying citrus right now because of its high vitamin C concentration [and people's goals of building immunity during the pandemic]. My wish is that they would abandon this tactic. It hurts consumers, it hurts farmers." She suggests EWG use its resources to find a way to encourage people to eat produce.

But EWG pushes back on that idea, arguing that “legal limits aren’t always safe.”

“EPA’s tolerances are often far higher than what many scientists believe is safe -- particularly for pregnant women, babies, and young children,” said EWG president Ken Cook. “EWG releases our Shopper’s Guide each year so consumers can make informed decisions that will let them reduce their family’s exposure to toxic pesticides while allowing them to eat plenty of healthy fruits and vegetables.”

Editor's note: Connie Diekman is on the Bayer LEAD Network, Leaders Engaged in Advancing Dialogue.

Show Sources

Environmental Working Group's 2021 Shopper's Guide to Pesticides in Produce, March 17, 2021.

Thomas Galligan, PhD, toxicologist, Environmental Working Group, Washington, DC.

Connie Diekman, registered dietitian; former president, Academy of Nutrition and Dietetics, St. Louis.

Carl K. Winter, PhD, cooperative extension specialist emeritus, University of California, Davis.

Teresa Thorne, executive director, Alliance for Food and Farming, Watsonville, CA.

Journal of Toxicology: "Dietary Exposure to Pesticide Residues from Commodities Alleged to Contain the Highest Contamination Levels."

Nutrition Today: "Low-Income Shoppers and Fruit and Vegetables."


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