Common chemicals sprayed on many crops each year are cloaked in bureaucratic uncertainties
By Meg Wilcox on June 15, 2022
Scientists have been raising growing concerns for decades over the use of toxic “forever chemicals,” so called because their strong molecular bonds can take hundreds of years to completely break down in the environment. Widely used in consumer products such as cookware and clothing, these substances are turning up everywhere from drinking water to our bloodstream. And now researchers are warning of yet another—and so far underrecognized— source of these troubling toxins: common pesticides. Nearly 70 percent of all pesticides introduced into the global market from 2015 to 2020 contained these chemicals or related compounds, according to a review paper recently published in Environmental Pollution. And the surge in their use has come without a full understanding of their potential impact on the environment and human health.
Forever chemicals—scientifcally known as perfuoroalkyl and polyfuoroalkyl substances, or PFASs—are a subset of so-called fuorinated chemicals, which possess strong carbon-fuorine bonds. That means such chemicals are both highly stable and useful in products designed to repel grease and water. But it also means they do not readily biodegrade. Though governments have been working to limit the use of PFASs, those eforts are complicated by difering technical defnitions of which fuorinated chemicals are technically PFASs—and as such pose a risk to people and the environment. Many chemicals considered PFASs in much of the rest of the world are not classifed this way in the U.S. This situation could leave communities exposed to harmful chemicals, including pesticides that contain fuorinated compounds and are sprayed on many diferent crops around the world every year.
Pesticides made from fuorinated chemicals, commonly referred to as fuorinated pesticides, “can be incredible molecules that meet a lot of the challenges that exist in agriculture,” says study coauthor Diogo Alexandrino, a researcher at the University of Porto in Portugal and a co-author of the Environmental Pollution paper. “But they should be properly vetted, and we should be aware that they can have a very huge impact on the environment, on biodiversity and eventually on our own health.”
Stability or Persistence?
Fluorinated chemicals, including PFASs, have been widely used in consumer products since the 1940s. But in the following decades scientists began realizing that these chemicals persisted in drinking water and human bodies, and in the 1990s the Environmental Protection Agency began investigating PFASs. Nearly every U.S. resident now carries low levels of PFASs in their blood. These chemicals have been linked to testicular and kidney cancers, reproductive disorders, thyroid disease, high cholesterol levels, reduced immune response and even increased susceptibility to COVID-19. Based on these concerns, the U.S. Congress is weighing several bipartisan bills to restrict their use in food containers and cookware and to require the EPA to take comprehensive action to prevent PFAS pollution—including setting national limits on levels in drinking water. Under the Biden administration, the EPA has published a PFAS Strategic Roadmap for addressing the crisis. Eight states have already adopted laws to ban PFASs in certain products, especially food packaging—but not in pesticides.
Fluorinated pesticides first appeared on the market in the 1930s, but it is only in the past decade that this use has expanded so dramatically. This rise is linked to improvements in manufacturing processes and the expiration of patents that have allowed for wider competition, Alexandrino says.
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