Finding Healthier Food
If you choose 5 servings of fruits and vegetables a day from EWG's Clean 15 rather than the Dirty Dozen, you can lower the volume of pesticide you consume daily by 92 percent, according to EWG calculations. You'll also eat fewer types of pesticides. Picking 5 servings of fruits and vegetables from the 12 most contaminated would cause you to consume an average of 14 different pesticides a day. If you choose 5 servings from the 15 least contaminated fruits and vegetables, you'll consume fewer than 2 pesticides per day.
The Dirty Dozen™
Of the 12 most contaminated foods, 6 are fruits: apples, strawberries, peaches, domestic nectarines, imported grapes and domestic blueberries. Notable findings:
- Every sample of imported nectarines tested positive for pesticides, followed by apples (97.8 percent) and imported plums (97.2 percent).
- 92 percent of apples contained 2 or more pesticide residues‚ followed by imported nectarines (90.8 percent) and peaches (85.6 percent).
- Imported grapes had 14 pesticides detected on a single sample. Strawberries, domestic grapes both had 13 different pesticides detected on a single sample.
- As a category. peaches have been treated with more pesticides than any other produce, registering combinations of up to 57 different chemicals. Apples were next, with 56 pesticides and raspberries with 51.
Celery, spinach, sweet bell peppers, potatoes, lettuce and greens (kale and collards) are the vegetables most likely to retain pesticide contamination:
- Some 96 percent all celery samples tested positive for pesticides, followed by cilantro (92.9 percent) and potatoes (91.4 percent).
- Nearly 90 percent of celery samples contained multiple pesticides, followed by cilantro (70.1 percent) and sweet bell peppers (69.4 percent).
- A single celery sample was contaminated with 13 different chemicals, followed by a single sample of sweet bell peppers (11), and greens (10).
- Hot peppers had been treated with as many as 97 pesticides, followed by cucumbers (68) and greens (66).
The Clean Fifteen™
The vegetables least likely to test positive for pesticides are onions, sweet corn, asparagus, sweet peas, eggplant, cabbage, sweet potatoes and mushrooms.
- Asparagus, sweet corn and onions had no detectable pesticide residues on 90 percent or more of samples.
- More than four-fifths of cabbage samples (81.8 percent) had no detectible pesticides, followed by sweet peas (77.1 percent) and eggplant (75.4 percent).
- Multiple pesticide residues are extremely rare on vegetables low in overall contamination. No samples of onions and corn had more than one pesticide. Less than 6 percent of sweet potato samples had multiple pesticides.
- Of the low-pesticide vegetables, no single sample had more than 5 different chemicals.
The fruits least likely to test positive for pesticide residues are pineapples, avocados, mangoes, domestic cantaloupe, kiwi, watermelon and grapefruit.
- Fewer than 10 percent of pineapple, mango, and avocado samples showed detectable pesticides, and fewer than one percent of samples had more than one pesticide residue.
- Nearly 55 percent of grapefruit had detectable pesticides but only 17.5 percent of samples contained more than one residue. Watermelon had residues on 28.1 percent of samples, and 9.6 percent had multiple pesticide residues.
Methodology
The Shopper's Guide to Pesticides ranks pesticide contamination for 53 popular fruits and vegetables based on an analysis of 51,000 tests for pesticides on these foods, conducted from 2000 to 2009 by the U.S. Department of Agriculture and the federal Food and Drug Administration. Nearly all the studies on which the guide is based tested produce after it had been rinsed or peeled.
Contamination was measured in 6 different ways:
- Percent of samples tested with detectable pesticides
- Percent of samples with two or more pesticides
- Average number of pesticides found on a single sample
- Average amount (level in parts per million) of all pesticides found
- Maximum number of pesticides found on a single sample
- Total number of pesticides found on the commodity
For each metric, we ranked all of the foods based on their individual USDA test results, then normalized the scores on a 1-100 scale (with 100 being the highest). To get a commodity's final score, we added up the six normalized scores from each metric. The full Shopper's Guide list shows the fruits and vegetables in order of these final scores.
The goal is to include a range of different measures of pesticide contamination to account for uncertainties in the science. All categories were treated equally; for example, a pesticide linked to cancer is counted the same as a pesticide linked to brain and nervous system toxicity, and the likelihood of eating multiple pesticides on a single food is given the same weight as the amounts of the pesticide detected or the percent of the crop on which pesticides were found.
The EWG’s Shopper’s Guide is not built on a complex assessment of pesticide risks but instead reflects the overall pesticide loads of common fruits and vegetables. This approach best captures the uncertainties of the risks of pesticide exposure and gives shoppers confidence that when they follow the guide they are buying foods with consistently lower overall levels of pesticide contamination.