Stacy Robertson
Stacy Robertson
June 16, 2024 ·  5 min read

Kale One Of The Most Pesticide-contaminated Veggies You Can Buy In America

This article was originally published on June 26, 2019, and has since been updated.

The Environmental Working Group (EWG) has released its ‘Dirty Dozen’ report and Kale has ranked third only behind strawberries and spinach when it comes to pesticide contamination [1].

Each year, the EWG analyzes Department of Agriculture test data to identify which supermarket produce are most contaminated with pesticide residues.

In 2009, kale first made EWG’s Dirty Dozen list coming in eighth, but despite its growing popularity in recent years, the USDA stopped doing regular produce tests on it [2].

“Kale is a popular food item that’s showing up more and more often on the plates of many Americans, and yet the USDA has not tested kale for almost a decade, which is concerning,” Carla Burns, EWG’s research analyst, told FOX Business.

Here is the full list of the “Dirty Dozen” fruits and vegetables and how they rank:

  1. Strawberries
  2. Spinach
  3. Kale
  4. Nectarines
  5. Apples
  6. Grapes
  7. Peaches
  8. Cherries
  9. Pears
  10. Tomatoes
  11. Celery
  12. Potatoes

Kale samples contained traces of Datchal

After analyzing 2017 tests data from the US Department of Agriculture, the group found that more than 92% of kale sample contained residue of at least five different pesticides, and the most contaminated sample had 18 different pesticide residues, despite the fact that they were thoroughly washed. 

“The main route of pesticide exposure for most Americans who do not live or work on or near farms is through their diet. Studies have shown that eating fruits and vegetables free of pesticides benefits health, and this is especially important for pregnant women and children,” Carla Burns said.

The EWG also found that almost 60 percent of the kale samples tested positive for a pesticide called DCPA-  marketed under the name Datchal- which is known as a possible human carcinogen [3].

Pesticides and human diseases

Although scientists are still figuring out the link between pesticides and human disease, studies have linked certain pesticides to diabetes, infant autism, cancer, and attention deficit hyperactivity disorder (ADHD) in children and young teens.

In the late 1950s, Datchal was introduced in the US as a weed-killer for vegetables, cotton, strawberries, and beans. By the 1990s, it was mostly used to tame weeds on golf courses and residential lawns. By 2005, the product’s US manufacturers had suspended most uses of Dacthal amid concerns that it was leaching into groundwater.

A few years later, all uses of the herbicide on crops were prohibited by the European Union. Today, the only products that contain Dacthal in the US are kale, eggplant, sweet potatoes, and turnips.

So far, the EPA has found ” suggestive evidence ” that Dacthal could cause cancer. Based on a two-year study that linked DCPA to thyroid and liver tumors in rats, the organization has listed the herbicide as a possible carcinogen, however, the effects on humans haven’t been tested [4].

Other pesticides

The EWG analysis also found that 30% of the kale samples contained cypermethrin and bifenthrin – two insecticides that have been classified by the EPA as a possible human carcinogen based on studies in mice.

Excessive exposure to these chemicals could cause headaches, nausea, and neurological issues, such as numbness and tingling.

Is organic food the way to go?

EWG recommends that shoppers opt for organic versions of the veg items and fruits which feature on this year’s ‘dirty dozen’. 

“We were surprised kale had so many pesticides on it, but the test results were unequivocal. Fruits and vegetables are an important part of everyone’s diet, and when it comes to some conventionally grown produce items, such as kale, choosing organic may be a better option,” said EWG toxicologist Alexis Temkin.

However, it also says that if the organic versions are not available, it’s still a good idea to continue to eat fresh produce, as the benefit outweighs the risk.

“The health benefits of a diet rich in fruits and vegetables outweigh the risks of pesticide exposure,” Burns said.

Pesticides and its risks to farmers

Although contaminated fruits and vegetables may wind up at grocery stores and restaurants, farmers are exposed to higher quantities of pesticides. According to the EPA, respiratory and skin contact with Dacthal is “expected among agricultural and horticultural professionals” who work with the chemical, though it doesn’t identify the risk of exposure.

Workers who grow kale and other vegetables run the risk of coming into direct contact with herbicides which may increase farmers’ risk of non-Hodgkin’s lymphoma, cancer that develops in the lymphatic system.

‘Unfounded Safety Fears’

However, in a statement to FOX Business, Teresa Thorne, executive director of the Alliance for Food and Farming (AFF) said based on peer-reviewed studies, EWG’s lists “are not scientifically supportable.” She added that it is time to stop calling non-organic fruits and vegetables ‘dirty’ as it perpetuates unfounded safety fears [5].

“There are many ways to promote organic produce without resorting to disparaging the more accessible forms of fruits and veggies that the science has repeatedly shown are safe,” Teresa Thorne said in a statement. “For example, the AFF has a webpage at with lots of positive information for consumers about organics.”

EWG’s ‘Clean 15’ list and how they rank

The list also highlights the cleanest produce on shelves.

  1. Avocados
  2. Sweet Corn
  3. Pineapples
  4. Frozen Sweet Peas
  5. Onions
  6. Papayas
  7. Eggplants
  8. Asparagus
  9. Kiwis
  10. Cabbages
  11. Cauliflower
  12. Cantaloupes
  13. Mushrooms
  14. Honeydew Melons

The Bottom Line

It is always best to consume fruits and vegetables than to not, organic or otherwise. Not consuming out of fear does not yield better results. Organic is ideal, but it does not always suit our budgets. Let’s just do the best we can with what we got.                                               


  1. Passy, Jacob. Over 92% of kale samples contained two or more pesticides, study finds. Retrieved from 27 March 2019.
  2. Bursztynsky, Jessica. Kale is now one of the most pesticide-contaminated vegetables. Retrieved from 21 March 2019.
  3. Scipioni, Jade. Kale rejoins the ‘Dirty Dozen’ list as one of the most contaminated with pesticides. Retrieved from 20 March 2019.
  4. Bendix, Aria. Kale Is Now One of The Most Pesticide-Contaminated Vegetables. Retrieved from 29 March 2019.
  5. Fitzmaurice, Rosie. Kale is one of the most pesticide-contaminated veggies you can buy in America. Retrieved from 21 March 2019.