Dirty Dozen or Clean Fifteen? See Where Your Favorite Produce Ranks This Year

Every year, the Environmental Working Group (EWG) issues a report that lists the fruits and vegetables that are most and least contaminated by pesticides. The new 2022 Shopper's Guide to Pesticides in Produce provides the most up-to-date information, based on tests conducted by the U.S. Department of Agriculture (USDA) and the Food and Drug Administration (FDA).

The 2022 Shopper's Guide reveals that pesticide residues can be found on 70% of non-organic produce, which reflects a continuing trend from last year. A number of pepper varieties made their way onto the Dirty Dozen list, thanks to worrisome levels of pesticides known to harm the human nervous system, including some that are banned from use on certain U.S. crops and entirely in Europe. 

This year's report also removed three crops from the Clean Fifteen list—eggplant, cauliflower, and broccoli—since these have not been tested by the USDA or FDA since six or more years. They were replaced by mangoes, watermelons, and sweet potatoes.

The USDA tests a subset of over 44,000 fruits and vegetables each year. Prior to testing, it washes and peels the items as one would do at home, which creates a fairly accurate replica of one's likely exposure. The EWG takes 46 of these items that have data from the most recent samplings, preferably done in the past one to two years. 

It then ranks these items by considering six different measures of pesticide contamination—the percent of samples with detectable pesticides and with two or more detectable pesticides, the average number of pesticides found on a single sample and in parts per million, the maximum number of pesticides found on a single crop, and total number found on the crop. All categories are weighted equally, and each food receives a total score, which creates the final lists. 

So, here's what you should know about produce in U.S. grocery stores today:

EWG'S Dirty Dozen for 2022

• Strawberries
• Spinach
• Kale, collard and mustard greens
• Nectarines
• Apples
• Grapes
• Bell and hot peppers
• Cherries
• Peaches
• Pears
• Celery
• Tomatoes

EWG's Clean Fifteen for 2022

• Avocados
• Sweet corn
• Pineapple
• Onions
• Papaya
• Sweet peas (frozen)
• Asparagus
• Honeydew melon
• Kiwi
• Cabbage
• Mushrooms
• Cantaloupe
• Mangoes
• Watermelon
• Sweet Potatoes

The first list, the Dirty Dozen, are the foods that were contaminated with more pesticides than any of the others that were tested. These are the ones worth buying organic, if possible, because that's where you'll get the biggest bang for your buck.

The EWG says, "More than 90% of samples of strawberries, apples, cherries, spinach, nectarines, and grapes tested positive for residues of two or more pesticides," and, "on average, spinach samples had 1.8 times as much pesticide residue by weight as any other crop tested." Sydney Swanson, a Healthy Living Science Analyst at EWG, told Treehugger that she was surprised the USDA "detected 101 different pesticides on peppers and 103 different pesticides on leafy greens."

The second list, the Clean Fifteen, are the foods with the least amount of pesticide contamination. "Avocados and sweet corn were the cleanest produce—less than 2% of samples showed any detectable pesticides," and less than 5% of these samples had residues of two or more pesticides. These are the non-organic items you can buy without feeling too concerned.

Does Organic Make a Difference?

The EWG explains that almost all the pesticides detected fall within legal limits, as determined by the U.S. government, but legal does not necessarily mean safe. 

"Pesticides are toxic by design. Although they’re meant to kill pests such as fungi, insects and plants, many pesticides are also linked to serious human health issues, including hormone disruption, brain and nervous system toxicity, and cancer," a press release states.

The EWG cites research from Harvard University that found eating produce with high levels of pesticides "may offset the protections eating such foods normally provides against cardiovascular disease and mortality." Researchers at Harvard have also found that people who eat foods high in pesticides tend to have lower fertility rates (more difficulty getting pregnant) and higher levels of pesticides in their urine. When people make the switch to organic produce, their urinary pesticide levels drop rapidly, providing a clear marker of exposure.

There's also concern about children's exposure to pesticides, as children are more sensitive and vulnerable to potential toxicity. The Food Quality and Protection Act of 1996 required the EPA to implement tighter pesticide controls to protect children, but the EWG's investigations have shown that the EPA has failed to do so: "This tenfold margin of safety was not included in the EPA’s allowable limits for almost 90% of the most common pesticides."

The EWG notes that the USDA and FDA neglect to test certain crops for certain pesticides with the frequency that it should, even those marketed to infants and children—despite the USDA stating that as a goal. "No commodities are tested annually, but some–including baby food, last tested in 2013, and baby formula, last tested in 2014–are tested particularly infrequently." Nor does it ever test for glyphosate, the most widely-used pesticide in the country. This seems a gross oversight.

As Swanson told Treehugger by email, "A class of insecticides called organophosphates, which includes the well-known insecticide chlorpyrifos, is linked to severe brain damage in children and fetuses. Three 2011 epidemiological studies on American mothers revealed a clear association between exposure to organophosphates during pregnancy and impaired learning and memory in children. Just last year, EPA banned all uses of chlorpyrifos on crops grown for food, a move that EWG applauded. However, chlorpyrifos is just one of the many organophosphates used on produce and EWG urges EPA to ban all uses of this class of insecticides."

Don't Skip Those Five Servings a Day

The report does not wish to scare people off from eating fruits and vegetables, even those from the Dirty Dozen list. It states clearly at the beginning, "A critical part of a healthy diet includes a combination of fruits and vegetables, regardless of how they are grown." But if you do feel concerned about pesticide consumption, then these lists will be immensely helpful in making informed decisions.

You can find all information relating to the 2022 Shopper's Guide here.