The agricultural industry is addicted to pesticides, and the entire world is paying the price. The US Environmental Protection Agency (EPA) reports that global pesticide use in 2012 amounted to approximately six billion pounds. Unfortunately, they haven’t published a report since then, but the number likely hasn’t improved and may have gotten worse.
While the term “pesticide” implies that these chemicals target and kill “pests,” a better name would be “biocides” (destroyers of life) because they do a lot more than poison pests.
Pesticides poison insects and pollinators; contaminate soil, water, and air; and can cause harm to farmworkers, agricultural communities, and people who eat produce sprayed with pesticides.
How common is it for US produce to have pesticide contamination? “Nearly 75% of nonorganic fresh produce sold in the US contains residues of potentially harmful pesticides,” according to the Environmental Working Group (EWG).
In this article, we’re going to review the most and least pesticide-contaminated produce, so you can make more informed fruit and vegetable purchases.
One thing to remember — thousands of studies, published in peer-reviewed journals, tell us clearly that eating more fruits and vegetables is good for your health. The more of these foods you eat, the longer you’re likely to live, and the less likely you are to develop most of the major chronic illnesses of our times.
Of course, in these studies, most of the fruits and vegetables were grown commercially, and many were contaminated with pesticides. So as you read about pesticide contamination of fruits and vegetables, please use this guidance as intended — to help you figure out which foods are most important to buy organic. If you can’t afford or access organic produce, don’t let that stop you from eating fruits and veggies. Remember, if you’re choosing between an organic donut and nonorganic kale… go for the kale. Just please wash it well if you can. (Here’s our article on how to wash pesticides off produce, if you’d like some guidance.)
Who Tests for Pesticide Residue?
We are relying on two organizations for the data on which fruits and vegetables tend to be the dirtiest and cleanest. The best known of these groups is EWG, which has published its Shopper’s Guide to Pesticides in Produce annually since 2004. Their produce guide identifies the least and most pesticide-contaminated produce — also known as their Clean Fifteen and Dirty Dozen — based on thousands of tests conducted by both the USDA and the FDA. In carrying out these tests, the produce is made “plate-ready” — washed, peeled, and ready to eat — before being analyzed. So the residues found in these studies are likely to be the same as those you’re exposed to when you eat conventionally grown fruits and veggies.
In 2020, Consumer Reports (CR) also released a pesticides in produce report based on USDA data. CR came up with their own ratings (which not surprisingly look a lot like the ones they bestow on clothes dryers and new cars), by running the USDA numbers through several filters. These include the total number of pesticides; the level of pesticides on fruits and vegetables; the frequency with which they were detected; and their toxicity. CR factors in the pesticide’s Food Quality Safety Factor (FQPA), which is published by the Environmental Protection Agency (EPA) to avoid underestimating potential harms.
The CR findings overlap significantly with those of EWG. But unlike EWG, CR makes distinctions between US-grown and imported foods, as well as conventional and organic.
Below, we summarize EWG’s Dirty Dozen and Clean Fifteen. Bear in mind as you go through the list that they are looking exclusively at conventionally grown produce, not organic. And, of course, your best choice will almost always be homegrown food, since you can control the methods used to nourish and protect your crops.
If you can’t grow any or all of your own produce, and you can’t afford universally organic produce or can’t access it in your community, this shopper’s guide can help you make wise consumer choices. Use it when you shop, whether at the grocery store, farmers market, or wherever you buy fresh produce, to help you determine which foods to buy organic.
One more thing before we dive in — this guide looks at pesticide residues only at the consumer level. In some cases, the ratings might be very different if the researchers factored in the pesticide exposure of farmworkers and communities where the crops are grown.
For example, conventional imported bananas are rated “very good” by CR (because the peel provides pesticide protection for the fruit). But public health research shows that farmworkers exposed to the pesticides used on conventional bananas develop up to 80% more genetic anomalies (i.e., potentially cancer-causing mutations) than those who work in organic or “ecological” farms that do not use conventional pesticides.
We are not aware of any convenient database or app to help you prioritize food choices to protect farmworkers. If this is important to you, our recommendation is to choose organic when you can — and especially so with foods that are imported from countries that have lax pesticide and worker protection regulations.
The Dirty Dozen: The Most Pesticide-Contaminated Produce
These fruits and vegetables are the foods with the most pesticide residues and are therefore the ones that are most important to buy organic if you can.
If you want to avoid exposure to multiple noxious chemicals, including dangerous fumigants that build up in the plant tissue, the fruit, and the soil, the most important food to only buy organic is the strawberry. Most of the fresh strawberries sold in the US come from California. Data from 2015 revealed that, per acre, strawberries receive 60 times more pesticide application by weight than corn, which itself is a pesticide-intensive crop. In fact, a jaw-dropping 99% of nonorganic strawberry samples had detectable pesticide residue.
But it wasn’t just the amount — the variety and toxicity of the chemicals were also problematic. While most crops showed residues of just over 2 pesticides per sample, strawberries averaged almost 8 — with 30% at 10 or more. And some of these pesticides, according to EWG, “have been linked to cancer and reproductive damage, or… are banned in Europe.”
If you like strawberries (and a lot of us do!), you have a few options. You can grow them yourself. (It’s not that hard, and you don’t need a lot of land. Even a container on a sunny porch should do the trick). Or, if you want to buy fresh or frozen strawberries, CR recommends choosing organic when possible.
If strawberries win the dubious distinction of the highest amount of pesticides, spinach holds the distinction of highest pesticide residues by weight. The biggest culprit in testing was permethrin, a neurotoxin insecticide banned in Europe that’s been linked to ADHD and various neurological impairments in children.
And speaking of bans, let’s talk about DDT for a minute. The pesticide that was banned in the US in 1972 after being indicted for multiple harms in Rachel Carson’s book Silent Spring was still shockingly found on 40% of spinach sampled by the USDA in 2016. DDT, like many other pesticides, has a nasty ability to persist in the environment — even after almost half a century.
Your best bet, aside from growing your own spinach, is buying organic spinach, according to CR. Next best is imported frozen spinach, as it’s lower in pesticides than spinach grown in the US. And it’s best to always wash fresh spinach well, as pesticide levels were higher in unwashed spinach than in the washed spinach tested by the USDA.
3. Kale, Collards, & Mustard Greens
Given leafy greens’ (like kale) well-justified popularity as nutritional powerhouses, I’m sad to report that they’re among some of the most contaminated crops in the US. In 2017, the USDA found that almost 60% of nonorganic kale samples were contaminated with the herbicide DCPA (marketed as Dacthal), which has been banned in Europe since 2009 because of cancer risks. And in 2019, 35% of examined samples of collard and mustard greens were also contaminated with Dacthal. DCPA’s main application is to kill crabgrass, which can outcompete edible leafy greens in poor soil conditions. Rather than remedy the soil, farmers are told to keep pouring on the chemicals.
The problem here is that DCPA was identified as a possible human carcinogen by the EPA as early as 1995. The data was so alarming, the manufacturer actually petitioned the EPA in 2005 to terminate its use on a variety of crops. Unfortunately, the ag industry has ignored the science and continues to douse our leafy greens in it. In the US, the only kale, collards, and mustard greens deemed generally free from DCPA are those grown organically.
Fresh, nonorganic peaches are among the foods with the most pesticides in the US. Samples examined by the USDA found residues of 56 separate pesticides, with fungicides making up the majority of the chemicals. Fludioxonil, a seed-targeted fungicide, was on nearly 90% of all samples tested, with some even exceeding maximum allowable amounts.
Peaches also have residues of multiple neonicotinoids (also known as neonics — as if it were an affectionate nickname, which they really don’t deserve). Neonics are insecticides that attack an insect’s nervous system and may be responsible for mass pollinator die-offs. Some neonics may also harm wildlife as well as human health. According to one 2020 study, neonic exposure may cause “chronic health effects ranging from acute respiratory, cardiovascular, and neurological symptoms to oxidative genetic damage and birth defects.”
If possible, stick to organic peaches. CR also reported that nonorganic, canned peaches are low in pesticides and received an “excellent” rating. While we don’t typically recommend canned fruit, if you do choose to buy canned peaches, look for those in organic fruit juice instead of syrup.
Pears moved up on the Dirty Dozen this year, from number 10 to number 5, due to most pear samples showing contamination from at least five different pesticides. Four out of 10 samples of nonorganic pears were found to have residue of pyrimethanil, a fungicide shown to cause multi-organ failure and endocrine disruption in tree frogs. The USDA also classifies it as a Group C (potential) carcinogen.
A quarter of pear samples had contamination with o-Phenylphenol, a mold growth retardant whose jocular rhyming name belies its nasty effects. It’s a known carcinogen, suspected hormone disruptor, and developmental toxin.
When buying fresh pears, choose organic if possible. Both domestic and imported pear samples were rated “excellent” by CR.
Named after the divine drink of the Olympian gods, it’s a cruel irony that these delicious fruits are often fouled by pesticide residues. The USDA found 33 pesticide residues in nectarine samples, including 5 known or probable carcinogens, 17 suspected hormone disruptors, and 6 developmental or reproductive toxins. Oh, and if that’s not bad enough, they were also found to contain 10 chemicals toxic to honeybees, our most important and most endangered pollinators.
The good news is, organic nectarines are low in pesticides, according to CR’s data.
At first blush, apples look pretty good. They’re treated with fewer pesticides than many other crops, averaging a little over four pesticide residues per sample. And they aren’t heavily treated while growing. The problem occurs after harvest when conventional apples are bathed in a chemical named diphenylamine, which keeps their skins pretty while they’re in cold storage. American regulators decided that diphenylamine didn’t pose any unacceptable risks — in contrast to European officials, who were swayed by evidence that by-products of diphenylamine may contribute to cancers of the stomach and esophagus. For this reason, conventional American-grown apples are banned in Europe.
Some bioengineered apples have also been introduced for cosmetic rather than functional reasons. Arctic apples, for example, are spliced with genes that prevent the flesh from browning when cut open. This doesn’t stop them from degrading, mind you — it just keeps the color white. (To avoid this dreaded condition, you can either eat them once cut, soak them in diluted lemon juice, or just be okay with apples that turn brown when their cut skin is exposed to the air.) Since BEs (GMOs) are viewed by some as a giant uncontrolled experiment in overriding the laws of nature — and there’s some reason to be at least a little skeptical about industry claims of safety — there are reasons you may want to avoid these so-called “Franken-apples.”
Your best bets when it comes to apples are homegrown (a well-tended apple tree can last up to five generations) or organic and non-GMO varieties.
EWG tells us that nonorganic grapes are loaded with pesticide residues, including 8 cancer causers, 17 suspected hormone disruptors, 10 neurotoxins, and 4 developmental or reproductive toxins. Plus, they’re often treated with 19 pesticides that are toxic to honeybees.
The only good thing you can say about nonorganic grapes is that they’re better than nonorganic raisins. According to EWG, almost 100% of samples of nonorganic raisins contained residues from two or more pesticides.
In a discrepancy that I can’t quite resolve, CR rates domestic, nonorganic grapes as very good, and imported ones as good. I hope they’ll publish the data behind their findings, as well as details of their methodology, so the public will be able to make grape decisions with more confidence. To be safe, my recommendation is to buy organic grapes and raisins.
Sadly, wines — and vinegars like red wine or balsamic — are also subject to potentially harmful doses of pesticides. Roundup is commonly used in nonorganic vineyards, at more than a pound and a half per acre, as are various other fumigants, herbicides, and pesticides. Pesticide residues found in wine rival those found in raw grapes, indicating that the wine-making process isn’t protective. These are good reasons to opt for wines made from organically grown grapes, if you choose to drink wine at all.
9. Bell & Hot Peppers
Overall, peppers had the most types of pesticides detected — a whopping 115 in total. Two pesticides, in particular, showed up more often than not among tested bell and hot pepper samples. Acephate and chlorpyrifos are organophosphate insecticides that attack the acetylcholinesterase enzyme in insects and mammals. This enzyme helps convert the neurotransmitter acetylcholine into acetic acid and choline compounds in the body.
Insecticides like acephate and chlorpyrifos are especially harmful to children’s developing brains and can cause nervous system problems and other unpleasant side effects. Although they’re banned in the EU, the US has not taken steps towards an outright ban on these toxic chemicals, which sadly still end up in our food supply.
To avoid potential exposure to any of the 115 potential pesticides found on bell and hot peppers, you might want to purchase organic as much as possible — or grow your own.
Almost half of the cherries sampled by the USDA contained residues of bifenthrin, a neurotoxin that kills insects by paralysis. It’s moderately harmful to mammals (including humans) and can wreak havoc on fish and their marine ecosystems. It also appears to cause cancer in mice but not rats, so we really don’t know what that says about carcinogenesis in humans. (Our view on the use of animals in medical research is here.) But add to this chemical the residues of 42 others found on cherries by USDA testing, and you have a recipe for individual and environmental concern.
Aside from homegrown cherries, your best bets here are frozen, domestic, organic cherries. Even imported fresh organic cherries were rated only “fair” by CR, based on suspicions of inadequate oversight of organic standards by countries such as Turkey and China. Fresh organic cherries could be a solid choice, too, if you have access to them.
Blueberries are back on the Dirty Dozen list after remaining off it for several years. Unfortunately, they gained a spot back due to an increase in pesticide residues on tested samples, with over 90% showing detectable levels. The amount and variety of pesticides found also increased from 2014. Over 80% of samples show 2 or more pesticides with over 17 different pesticides represented across blueberry crops.
Although they’re only in less than 10% of samples, two organophosphate insecticides showed up on blueberries: phosmet and malathion. The former is banned in the EU, and the latter only approved for US greenhouse usage. But somehow, both have remained in regular circulation among conventionally grown blueberry crops. This is concerning, as both can damage the human nervous system. And children are especially vulnerable.
Detection of increased levels of fungicides and neonic insecticides is also very troubling, especially since the fungicide boscalid may have carcinogenic properties. Imported blueberries seem to have less pesticide contamination according to CR, but organic is still recommended over conventionally grown.
12. Green Beans
Green beans are new to the Dirty Dozen list this year due to the detection of several banned pesticides. In 2011, the EPA banned the use of acephate on green beans, and in 2016 reduced tolerable amounts after the banning, trying to crack down on violations. But as we can see from EWG’s findings, that wasn’t enough to stop acephate usage. In fact, one of the samples tested had pesticide residues equaling 500 times the allowable limit!
EU-banned pesticides detected on US green beans also included carbendazim, bifenthrin, and chlorothalonil, with the former two classified as potential human carcinogens.
In all cases, the pesticide amounts, varieties, and the number of contaminated samples all increased since 2016. Consumer Reports actually ranked fresh green beans with one of their worst scores, making them an important produce item to buy organic. Canned or frozen green beans fare slightly better as well.