Kale rejoins the 'Dirty Dozen' list as one of the most contaminated with pesticides

For the first time in a decade, kale, the popular green leaf cabbage adored by health enthusiasts worldwide, has rejoined the 'Dirty Dozen' list of fruits and vegetables with the most pesticide residues.

On Wednesday, the Environmental Working Group released its annual Shopper's Guide to Pesticides in Produce, which analyzes Department of Agriculture test data to identify which supermarket produce have the most --and least-- contamination. Researchers said they were shocked that kale made the list this year.

“We were surprised kale had so many pesticides on it, but the test results were unequivocal,” EWG Toxicologist Alexis Temkin, Ph.D. said in a press release.

Kale came in third on this year's list after strawberries, which also topped the list last year, and spinach. Samples of both kale and spinach had about 10 to 80 percent more pesticide residue by weight than any other crop.

What's more, in USDA's most recent round of tests, more than 92 percent of conventionally grown kale samples had at least two pesticide residues, with some samples containing residues from as many as 18 different pesticides.

Kale first made EWG's Dirty Dozen list in 2009, coming in eighth, but the following year, the USDA stopped doing regular produce tests on it, even despite its growing popularity over the past decade.

"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.

Burns added that of the pesticides found on kale, one in particular stood out the most.

"Dacthal, or DCPA, which was classified by the EPA as a possible human carcinogen. It was found on nearly 60 percent of kale samples," Burns said. Dacthal has been prohibited for use on crops in the European Union since 2009.

Additionally, recent EWG-commissioned tests of kale from grocery stores found that on two of eight samples, Dacthal residues "were comparable to the average level reported by the USDA."

But the list isn't all bad news. Burns says it also highlights the cleanest produce on shelves, and mushrooms were a new addition to the list this year, shifting mangoes off the list.

EWG adds that the best way to reduce pesticide exposure on foods "is by opting for organic varieties on the 'Dirty Dozen' list."

"It’s important to note that eating an assortment of fruits and vegetables is key for a healthy diet, and we recommend that all people should consume more fruits and vegetables whether they are conventional or organic," Burns says.

However, in a statement to FOX Business, the Alliance for Food and Farming (AFF) -- which represents organic and conventional farmers of fruits and vegetables -- said based on several peer reviewed studies, EWG's lists "are not scientifically supportable."

“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, executive director of the AFF, said in a statement. “For example, the AFF has a webpage at safefruitsandveggies.com with lots of positive information for consumers about organics."

Thorne added that it is time to stop "calling non-organic forms of healthy fruits and veggies ‘dirty’ and perpetuating unfounded safety fears that may negatively impact  consumers’ purchasing of both organic and conventional produce."

Here are EWG's full results.

EWG's 2019 Dirty Dozen list

1. STRAWBERRIES

2. SPINACH

3. KALE

4. NECTARINES

5. APPLES

6. GRAPES

7. PEACHES

8. CHERRIES

9. PEARS

10. TOMATOES

11. CELERY

12. POTATOES

EWG's CLEAN 15 LIST FOR 2019

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. BROCCOLI

14. MUSHROOMS

15. HONEYDEW MELONS