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Mama always said to eat your vegetables. (Well at least mine did.) While fruits and veggies are consistently touted for a multitude of health benefits — antioxidants, immunity boosting powers, diabetes preventatives, and a bajillion vitamins (roughly speaking) — some are safer to eat than others.

Meet the “Dirty Dozen” and the “Clean Fifteen” — two lists of produce considered the least and most safe due to their pesticide levels. The report, compiled by Environmental Working Group (EWG) contains more items, including peaches and kale, that aren’t safe when not labeled “organic.”

Check out the lists, why certain foods are safer than others, and just how seriously we should consider organic labels on our fruits and veggies.

The EWG just released their Shopper’s Guide to Pesticides in Produce. Now in its ninth year, the list ranks pesticide contamination of nearly 50 popular fruits and veggies based on more than 28,000 samples tested by the U.S. Department of Agriculture and Food and Drug Administration. With the results of the data compiled into a list, dubbed “The Dirty Dozen,” U.S. consumers can lower pesticide intake by avoiding the 12 most contaminated fruits and vegetables.

The Dirty Dozen — 2013
  • Apples
  • Celery
  • Cherry tomatoes
  • Cucumbers
  • Grapes
  • Hot peppers
  • Nectarines
  • Peaches
  • Potatoes
  • Spinach
  • Strawberries
  • Sweet bell peppers.

While the name “dirty dozen” does have a ring to it, the number doesn’t quite add up this year. For the second year, the EWG has expanded the 12-item list with a “plus” category to highlight two additional cropsdomestically-grown summer squash and leafy greens (specifically kale and collards).

While these crops did not meet the traditional dirty dozen criteria (we’ll get into that later), they were regularly loaded with pesticides. And studies suggest pesticides can be toxic to the nervous systemNeurotoxicity of pesticides. Keifer, M.C., Firestone, J., University of Washington, Department of Medicine, Seattle, WA. Journal of Agromedicine, 2007;12(1):17-25.Peripheral nervous system function and organophosphate pesticide use among licensed pesticide applicators in the Agricultural Health Study. Starks, S.E., Hoppin, J.A., Kamel, F., et al. Department of Occupational and Environmental Health, University of Iowa, Iowa City, Iowa. Environmental Health Perspective, 2012 Apr;120(4):515-20..

While all those nasty chemicals may get you down, there are conventionally grown fruits and veggies the EWG considers safe to buy, called the “Clean Fifteen” and they are considered safe to purchase even without an organic label.

The Clean Fifteen, 2013
  • Asparagus
  • Avocados
  • Cabbage
  • Cantaloupe
  • Sweet corn
  • Eggplant
  • Grapefruit
  • Kiwi
  • Mangoes
  • Mushrooms
  • Onions
  • Papayas
  • Pineapples
  • Sweet peas
  • Sweet potatoes

Breaking Down the Clean and Dirty

In order to compare the fruits and vegetables, the EWG examined six measures of pesticide contamination ranging from percent of samples with two or more detectable pesticides to the total number of pesticides found. For each metric, they ranked the foods on individual USDA test results, then normalized the scores on a 1 to 100 scale. (Check out the full list of all 48 fruits and veggies tested here.)

It’s scary stuff. Tests in 2008 found harmful pesticide residues on some summer squash, including zucchini. Even more alarming, the specific pesticides — organochlorines — were phased out of agricultural use in the 1970s and 80s, yet they still linger in some farms’ soil. While major produce growers claimed 98 percent of fresh fruits and vegetables tested have no detectible pesticide residues, according to the USDA’s Pesticide Data Program Report, the EWG says residues lingered on 67 percent of produce samples even after they were washed or peeled.

There’s a reason pesticides are toxic. They’re designed specifically to kill living things, such as insects and fungi that can get in the way of producing a healthy crop. But many pesticides have been linked to dangerous health problems in humans, including cancerous tumors, Parkinson’s disease, and poisoning in childrenPesticides and cancer. Dich, J., Zahm, S.H., Hanberg, A., et al. Department of Cancer Epidemiology, Karolinska Institute and Radiumhemmet, Karolinska University Hospital, Stockholm, Sweden. Cancer Causes Control, 1997 May;8(3):420-43.Pesticide exposure and risk for Parkinson’s disease. Ascherio, A., Chen, H., Weisskopf, M.G., et al. Department of Nutrition, Harvard School of Public Health, Boston, MA. Annals of Neurology, 2006 Aug;60(2):197-203.Professional exposure to pesticides and Parkinson disease. Elbaz, A., Clavel, J., Rathouz, P.J., et al. INSERM, U, Paris, France. Annals of Neurology, 2009 Oct;66(4):494-504.Pesticide exposure in children. Roberts, J.R., Karr, C.J., Council On Environmental Health. Pediatrics, 2012 Dec;130(6):e1765-88..

The Takeaway

Pesticides are scary, but you should still eat your veggies. Organic produce can sometimes carry a slightly higher price tag (though not always — produce co-ops, for instance, help cut costs), but its obvious people would rather not choose to chomp on chemicals if they don’t have to. Lists like the dirty dozen and clean fifteen make it easier for shoppers to affordably avoid toxic chemicals. The message behind the clean fifteen list is that it’s actually OK to skip out on organic labels sometimes to save a little cash, while still investing in nutritious foods which contribute to our overall health. Considering all produce is relatively expensive in comparison to many processed foods, it’s pretty cool consumers get the easy pass on some fresh-from-the-grove fruits, and picked-from-the-garden vegetables.

Do you only buy your fruits and vegetables if they have an organic label? Or do you think it makes sense to abide by the dirty dozen/clean fifteen lists? Let us know in the comment section below or tweet the author @nicmdermott.