EWG's 2019 Shopper's Guide to Pesticides in Produce™

Over Half of Samples of Kale Tainted With Possible Cancer-Causing Chemical

WEDNESDAY, MARCH 20, 2019

Nearly 70 percent of the produce sold in the U.S. comes with pesticide residues, according to EWG’s analysis of test data from the Department of Agriculture for our 2019 Shopper’s Guide to Pesticides in Produce™.

The most surprising news from the USDA tests reveals that the popular health food kale is among the most contaminated fruits and vegetables. More than 92 percent of kale samples had two or more pesticide residues detected, and a single sample could contain up to 18 different residues. The most frequently detected pesticide, found on nearly 60 percent of kale samples, was Dacthal, or DCPA – classified by the Environmental Protection Agency since 1995 as a possible human carcinogen, and prohibited for use in Europe since 2009.

Overall, the USDA found 225 different pesticides and pesticide breakdown products on popular fruits and vegetables Americans eat every day. Before testing, all produce was washed and peeled, just as people would prepare food for themselves, which shows that simple washing does not remove all pesticides.

The USDA had not tested kale for almost a decade. But even as its popularity as a food rich in vitamins and antioxidants has soared, the level and number of pesticide residues found on kale has increased significantly. EWG’s analysis places kale third on this year’s Dirty Dozen™, our annual ranking of the fruits and vegetables with the most pesticides.

EWG's Dirty Dozen for 2019

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

Each of these foods tested positive for a number of different pesticide residues and contained higher concentrations of pesticides than other produce. Key findings:

  • More than 90 percent of samples of strawberries, apples, cherries, spinach, nectarines, and kale tested positive for residues of two or more pesticides.
  • Multiple samples of kale showed 18 different pesticides.
  • Kale and spinach samples had, on average, 1.1 to 1.8 times as much pesticide residue by weight than any other crop.

Different fruits and vegetables can have vastly different levels and numbers of pesticides detected on the crop. All research agrees on the health benefits of a diet that includes fruits and vegetables, and eating fresh produce – organic or conventional, as budget allows – is essential for health.

The Shopper’s Guide is a resource designed to help you reduce your pesticide exposures as much as possible by indicating which produce to buy organic, and which conventional products are low in pesticide residue. That’s why we also analyzed the USDA data to produce the Clean Fifteen™, our list of the fruits and vegetables that have few, if any, detected pesticide residues.

EWG's Clean Fifteen 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

Relatively few pesticides were detected on these foods, and tests found low total concentrations of pesticide residues. Key findings:

  • Avocados and sweet corn were the cleanest. Less than 1 percent of samples showed any detectable pesticides.
  • More than 70 percent of Clean Fifteen fruit and vegetable samples had no pesticide residues.
  • With the exception of cabbage, all other produce on the Clean Fifteen tested positive for less than four pesticides.
  • Multiple pesticide residues are extremely rare on Clean Fifteen vegetables. Only 6 percent of Clean Fifteen fruit and vegetable samples had two or more pesticides.
See the full list of fruits and vegetables.

Health Benefits of a Diet Low in Pesticide Residues

A French study published in December in JAMA Internal Medicine, a journal from the American Medical Association, found that among nearly 69,000 participants, those with the highest frequency of organic food consumption had 25 percent fewer cancers than individuals who did not eat organic food.1 And in 2018, data from the Harvard University T.H. Chan School of Public Health Environment and Reproductive Health, or EARTH, study found a surprising association among study participants between the consumption of foods high in pesticide residues and fertility problems.2

These findings raise important questions about the safety of pesticide mixtures found on produce and suggest that people should focus on eating fruits and vegetables with the fewest pesticide residues. In fact, the most recent of several studies evaluating the impact of an organic diet found that after only six days of eating organic food, adults and children had on average a 60 percent reduction in the levels of synthetic pesticides measured in their urine, compared to when they were eating a conventional diet.3

The study, published in February in the journal Environmental Research, found that an organic diet can reduce the levels of chlorpyrifos, a neurotoxic pesticide that can harm the brain of the developing fetus; malathion, a pesticide classified as a probable human carcinogen; and clothianidin, a neonicotinoid pesticide that can harm bees.

Genetically Engineered Crops, or GMOs

Most processed foods typically contain one or more ingredients derived from genetically engineered crops, such as corn syrup and corn oil made from predominantly GMO starchy field corn. Yet GMO foods are not often found in the fresh produce section of American supermarkets. According to the USDA, a small percentage of zucchini, yellow squash and sweet corn is genetically modified.4 Most Hawaiian papaya is GMO. Genetically engineered apples and potatoes are also starting to enter the U.S. market.

In 2016, Congress passed a mandatory GMO disclosure law. But the final rule released by the Trump Administration, in December 2018, fails to require the clear, simple disclosure of all GMO foods using terms consumers understand. In addition to exempting highly refined ingredients like sugars and oils, the final rule forces companies to use confusing terms like “bioengineered” and fails to require comparable disclosure options as required by the law for consumers who may not be able to access digital disclosures like QR codes.

These limited disclosures are not required on eligible food product labels until January 2022. EWG advises people who want to avoid GMO crops to purchase organically grown produce such as sweet corn, papayas, zucchini and yellow squash.

For processed foods, look for items that are certified organic or bear the Non-GMO Project Verified label. EWG recommends that consumers check EWG’s Shopper’s Guide To Avoiding GMO Food, Food Scores database and EWG’s Healthy Living app, which identify foods likely to contain genetically engineered ingredients. GMO labeling is important, because agribusinesses are currently testing other varieties of GMO crops, which the USDA may approve in the future.

Dirty Dozen Plus™

As we have in the past, this year EWG has expanded the Dirty Dozen list to highlight hot peppers, which do not meet our traditional ranking criteria but were found to be contaminated with insecticides toxic to the human nervous system.

The USDA tests of 739 samples of hot peppers in 2010 and 2011 found residues of three highly toxic insecticides – acephate, chlorpyrifos and oxamyl – on a portion of sampled peppers at concentrations high enough to cause concern.5 These insecticides are banned on some crops but still allowed on hot peppers. In 2015, California regulators tested 72 unwashed hot peppers and found that residues of these three pesticides are still occasionally detected on the crop.6

EWG recommends that people who frequently eat hot peppers buy organic. If you cannot find or afford organic hot peppers, cook them, because pesticide levels typically diminish when food is cooked.

Pesticide Regulations

The federal government’s role in protecting our health, farm workers and the environment from harmful pesticides is in urgent need of reform. In the U.S, pesticide regulation, monitoring and enforcement is scattered across multiple federal and state agencies. In 1991 the USDA initiated the Pesticide Data Program and began testing commodities annually for pesticide residues, but we continue to be concerned about pesticide regulation in the U.S.

The USDA states that a goal of its tests is to provide data on pesticide residues in food, with a focus on those most likely consumed by infants and children. Yet there are some commodities that are not tested annually, including baby food (last tested in 2013), oats (last tested in 2014), and baby formula (last tested in 2014).7

This is troubling, because tests commissioned by EWG found almost three-fourths of samples of popular oat-based foods, including many that are consumed by children, had pesticide residue levels higher than what EWG scientists consider protective of children’s health.

The chief responsibility of deciding which pesticides are approved for use in the U.S., including deciding what conditions are placed on their approval and setting the pesticide residue levels on foods and crops, falls to the EPA. But primary enforcement authority for pesticide use on farms is left to states, and the responsibility of testing foods to determine dietary exposures to pesticides is divided between the USDA and the Food and Drug Administration. However, neither the USDA nor FDA regularly tests all commodities for pesticide residues, nor do the programs test for all pesticides commonly used in agriculture.

The pesticide registration process requires companies to submit safety data, proposed uses and product labels to be approved by the EPA. However, the EPA does not conduct its own independent testing of pesticides. Neither does its review fully capture the risks posed by pesticides, because of limitations in available data and failures in risk assessments such as excluding synergistic effects. This is concerning because scientists have found that the combination of two or more pesticides can be more potent than the use of the pesticides individually.

The primary pesticide law – the Federal Insecticide, Fungicide, and Rodenticide Act, or FIFRA – is far less health protective than the laws that protect the safety of our air, food, water and environment. There are many reasons EWG fights for pesticide regulation and reform: registration loopholes, limited public participation, outdated registration and pesticide registration backlogs, to name a few. These are examples of the potential undermining of marketplace safety as products with harmful health concerns can remain on the market. Not all pesticides registered under FIFRA adequately protect human health and the environment, and federal food tolerance residue levels often allow for higher exposure levels than public health advocates, including EWG, consider to be safe.

How You Can Avoid Pesticides

In general, people who eat organic produce consume fewer pesticides. In a study published in February, scientists evaluated the impact of an organic diet by monitoring the level of pesticides found in the urine of participating American families (both adults and children) while they maintained a conventional diet and then after switching to an all-organic diet. Before the organic diet intervention, they detected in the participants’ urine potential exposure to more than 40 different pesticides.8 After about a week of eating organic food, participants had on average a 60 percent reduction in the levels of synthetic pesticides measured in their urine, compared to when they were eating a conventional diet.

In 2015, scientists at the University of Washington found that people who report they often or always buy organic produce had significantly lower quantities of organophosphate insecticides in their urine samples. This was true even though they reported eating 70 percent more servings of fruits and vegetables per day than adults who reported they rarely or never purchase organic produce.9

The fertility studies demonstrate potentially subtle but important impacts of eating lower-pesticide-residue produce. These studies define low- and high-residue foods in a method similar to EWG’s guide. They use the same data source, the USDA’s Pesticide Data Program, and create a crop-level residue index that largely overlaps with EWG’s Dirty Dozen and Clean Fifteen lists.

The Washington researchers found that people’s self-reported dietary habits correspond to pesticide measurements in their bodies. In the EARTH study, male participants who reported the highest consumption of high-residue crops had higher concentrations of organophosphate and pyrethroid insecticides, and the herbicide 2,4-D in their urine, than participants who eat these foods less often.10

Fertility studies' classification of pesticide residues
High pesticide residue score Apples, apple sauces, blueberries, grapes, green beans, leafy greens, pears, peaches, potatoes, plums, spinach, strawberries, raisins, sweet peppers, tomatoes, winter squashes
Low to moderate pesticide residue score Apple juice, avocados, bananas, beans, broccoli, cabbages, cantaloupes, carrots, cauliflower, celery, corn, eggplants, grapefruits, lentils, lettuce, onions, oranges, orange juices, peas, prunes, summer squashes, sweet potatoes, tofu, tomato sauces, zucchini

In 2012, the American Academy of Pediatrics issued an important report that said children have “unique susceptibilities to [pesticide residues’] potential toxicity.” The organization cited research that linked pesticide exposures in early life to pediatric cancers, decreased cognitive function and behavioral problems. It advised its members to urge parents to consult “reliable resources that provide information on the relative pesticide content of various fruits and vegetables.” A key resource it cited was EWG’s Shopper’s Guide to Pesticides in Produce.11

Methodology

The Shopper’s Guide ranks pesticide contamination on 47 popular fruits and vegetables based on an analysis of more than 40,900 samples taken by the USDA and FDA. The USDA doesn’t test every food every year, so EWG generally uses data from the most recent one- or two-year sampling period for each food. The USDA doesn’t test honeydew melons and kiwis, so EWG uses data from the FDA’s pesticide monitoring for these crops.

Food Year Source
Apples 2015-2016 USDA PDP
Asparagus 2009-2010, 2017 USDA PDP
Avocados 2012 USDA PDP
Bananas 2012-2014 USDA PDP
Blueberries 2014 USDA PDP
Broccoli 2014 USDA PDP
Cabbages 2017 USDA PDP
Cantaloupes 2010-2012 USDA PDP
Carrots 2014 USDA PDP
Cauliflower 2012-2013 USDA PDP
Celery 2014 USDA PDP
Cherries 2014-2016 USDA PDP
Cherry tomatoes 2012 USDA PDP
Cucumbers 2015-2017 USDA PDP
Eggplants 2006 USDA PDP
Grapefruits 2015-2017 USDA PDP
Grapes 2016 USDA PDP
Green beans 2013-2016 USDA PDP
Honeydews 2008-2015 FDA
Hot peppers 2010-2011 USDA PDP
Kale 2017 USDA PDP
Kiwis 2008-2016 FDA
Lettuce 2015-2017 USDA PDP
Mangoes 2017 USDA PDP
Mushrooms 2012-2013 USDA PDP
Nectarines 2014-2015 USDA PDP
Onions 2017 USDA PDP
Oranges 2016 USDA PDP
Papayas 2011-2012 USDA PDP
Peaches 2014-2015 USDA PDP
Pears 2016 USDA PDP
Pineapples 2002 USDA PDP
Plums 2012-2013 USDA PDP
Potatoes 2016 USDA PDP
Raspberries 2013 USDA PDP
Snap peas 2017 USDA PDP
Spinach 2016 USDA PDP
Strawberries 2015-2016 USDA PDP
Summer squash 2012-2014 USDA PDP
Sweet bell peppers 2011-2012 USDA PDP
Sweet corn 2014-2015 USDA PDP
Sweet peas (frozen) 2003 USDA PDP
Sweet potatoes 2016-2017 USDA PDP
Tangerines 2012 USDA PDP
Tomatoes 2015-2016 USDA PDP
Watermelons 2014-2015 USDA PDP
Winter squash 2012-2013 USDA PDP

Nearly all the tests that serve as the basis for the guide were conducted by USDA personnel, who washed or peeled produce to mimic consumer practices. It is a reasonable assumption that unwashed produce would be likely to have higher concentrations of pesticide residues, as is typically found in California Department of Pesticide Regulation tests, which include unwashed, unpeeled produce.12

To compare foods, EWG looked at six measures of pesticide contamination:

  • Percent of samples tested with detectable pesticides.
  • Percent of samples with two or more detectable pesticides.
  • Average number of pesticides found on a single sample.
  • Average amount of pesticides found, measured in parts per million.
  • Maximum number of pesticides found on a single sample.
  • Total number of pesticides found on the crop.

For each metric, we ranked each food based on its individual USDA test results and then normalized the scores on a 1 to 100 scale, with 100 being the highest. A food's final score is the total of the six normalized scores from each metric. When domestically grown and imported produce items had notably different scores, we displayed them separately to help guide consumers toward lower-pesticide options. The Shopper's Guide full list shows fruits and vegetables in the order of these final scores.

Our goal is to show a range of different measures of pesticide contamination to account for uncertainties in the science. All categories were treated equally. The likelihood that a person would eat multiple pesticides on a single food was given the same weight as amounts of the pesticide detected and the percent of the crop on which any pesticides were found.

The 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 about the risks and consequences of pesticide exposure. Since researchers are constantly developing new insights into how pesticides act on living organisms, no one can say that concentrations of pesticides assumed to be safe today are harmless.

The Shopper’s Guide aims to give consumers the confidence that by following EWG’s advice, they can buy foods with fewer types of pesticides and lower overall concentrations of pesticide residues.

This article was adapted and updated from the 2018 Shopper’s Guide.

References:

  1. J. Baudry et al., Association of Frequency of Organic Food Consumption with Cancer Risk. JAMA Internal Medicine, 2018; 178(12):1597-1606. DOI: 10.1001/jamainternmed.2018.4357. Available at https://jamanetwork.com/journals/jamainternalmedicine/article-abstract/2707948
  2. Y-H Chiu et al., Association Between Pesticide Residue Intake from Consumption of Fruits and Vegetables and Pregnancy Outcomes Among Women Undergoing Infertility Treatment With Assistance Reproductive Technology. JAMA Internal Medicine, 2018. DOI: 10.1001/amainternmed.2017.5038. Available at jamanetwork.com/journals/jamainternalmedicine/article-abstract/2659557
  3. C. Hyland et al., Organic Diet Intervention Significantly Reduces Urinary Pesticide Levels in U.S. Children and Adults. Environmental Research, 2019. DOI: 10.1016/j.envres.2019.01.024. Available at: https://www.sciencedirect.com/science/article/pii/S0013935119300246
  4. U.S. Department of Agriculture, Economic Issues in the Coexistence of Organic, Genetically Engineered (GE), and Non-GE Crops. Economic Research Service, 2016. Available at https://www.ers.usda.gov/webdocs/publications/44041/56750_eib-149.pdf
  5. USDA, Pesticide Data Program. Agricultural Marketing Service. Available at www.ams.usda.gov/datasets/pdp
  6. California Department of Pesticide Regulation, Pesticide Residues on Fresh Produce. 2015. Available at www.cdpr.ca.gov/docs/enforce/residue/resi2015/rsfr2015.htm
  7. USDA, Pesticide Data Program. Agricultural Marketing Service. Annual Summary, Calendar Year 2017. Available at https://www.ams.usda.gov/sites/default/files/media/2017PDPAnnualSummary.pdf
  8. Baudry et al.
  9. C.L. Curl et al., Estimating Pesticide Exposure from Dietary Intake and Organic Food Choices: The Multi-Ethnic Study of Atherosclerosis (MESA). Environmental Health Perspectives, 2015. Available at ehp.niehs.nih.gov/1408197/
  10. Y-H Chiu, Comparison of Questionnaire-Based Estimation of Pesticide Residue Intake from Fruits and Vegetables with Urinary Concentrations of Pesticide Biomarkers. Journal of Exposure Science and Environmental Epidemiology, January 2018; 28(1):31-39. DOI: 10.1038/jes.2017.22
  11. American Academy of Pediatrics, Organic Foods: Health and Environmental Advantages and Disadvantages. American Academy of Pediatrics Committee on Nutrition and Council on Environmental Health, 2012; e1406 -e1415. DOI: 10.1542/peds.2012-2579. Available at pediatrics.aappublications.org/content/130/5/e1406
  12. California Department of Pesticide Regulation

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