Kale, watermelon and even some organic foods pose a high risk of pesticides, analysis shows

Watermelon, green beans and bell peppers are among the many common fruits and vegetables found in U.S. supermarkets that may contain unsafe levels of pesticides, according to an analysis published today by Consumer Reports.

The new report – which analyzed seven years of U.S. Department of Agriculture data on commonly eaten fruits and vegetables – provides one of the most comprehensive assessments to date of pesticides found in American produce. The data was based on nearly 30,000 samples of fruits and vegetables, including fresh, frozen, canned and organic, collected from grocery stores by the USDA as part of routine pesticide testing.

Consumer Reports built a massive database to analyze the data – and scored various foods to make actionable recommendations to help consumers shop and eat with less risk.

Consumer Reports found that pesticide residues posed a significant risk in about 20% of the 59 common foods examined in the study. Foods considered high risk included conventionally grown (i.e. non-organic) kale, blueberries, potatoes and peppers. Apples, grapes, peaches, tomatoes, spinach and celery were among the items considered moderate risk.

According to the study, organic fruits and vegetables generally contain much less pesticide residue than conventionally grown foods. But even a few organic foods posed some risk. For example, imported green beans posed a high risk and domestic potatoes a moderate risk. This raised questions about how these organic crops became contaminated with risky pesticides that are not approved for organic farming.

Imported, conventionally grown produce also posed higher risks than U.S.-grown foods in the study. Foods grown in Mexico, such as strawberries and green beans, were of particular concern. Mexican strawberries contain oxydemeton-methyl, part of a group of pesticides called organophosphates, which are neurotoxins. This category of insecticides can overstimulate the nervous system at high exposure levels and disrupt the developing nervous system in infants and children.

For Consumer Reports to consider the fruit or vegetable as high risk, only a relatively small portion of the samples had to be contaminated. The tests involved hundreds of samples for each food item collected from U.S. supermarkets over seven years. Only 4% of green bean samples tested contained high-risk pesticides.

But some of the levels found on contaminated beans were alarming: A 2022 sample of green beans had levels of methamidophos that were a hundred times higher than the levels Consumer Reports scientists consider safe. Methamidophos has been banned in the US and on green bean imports for more than a decade, raising questions about why it continues to appear in supermarket products.

It’s important to note that Consumer Reports scientists have stricter standards for what they consider safe than those of the Environmental Protection Agency – the US government agency that sets levels, also called tolerances. The Alliance for Food and Farming, an agriculture industry organization, notes that 99% of vegetables tested by the USDA meet government safety standards for pesticide residues. But many scientists – including those behind the Consumer Reports study – believe that EPA tolerances are often set far too high, putting consumers at risk.

β€œMany of these EPA tolerances do not reflect the best science,” said Michael Hansen, senior scientist at Consumer Reports. β€œThey were established a number of years ago – and do not take into account situations where there are multiple pesticide residues on one sample. The data is now available – and the computing power is now there – to more accurately estimate the actual risk.”

The strongest evidence of the dangers of pesticides comes from farm workers and pesticide applicators, who are exposed to much higher levels of the chemicals when they are applied to crops. Exposure to pesticides at work has been linked to a higher risk of Parkinson’s disease, several forms of cancer, diabetes and other health problems.

When it comes to consumers, the risks of eating food contaminated with pesticides increase over time. For most of the population, a single serving of contaminated fruit is unlikely to cause harm, but routine consumption of contaminated fruit or vegetables over months or years increases the risk.

Children and pregnant women are particularly vulnerable because some pesticides can be endocrine disruptors, which can interfere with hormones responsible for the development of important body systems, especially the reproductive system.

Over the next year, The Guardian will work with Consumer Reports to dig deeper into the findings of this study, looking for answers to how the U.S. food supply became contaminated by pesticides and what we can do about it.

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