PFAS increasingly added to pesticides, study finds

Despite widespread alarm about the health and environmental impacts of toxic PFAS, the chemicals are increasingly being added to pesticides applied in homes and crops across the US, according to a new study.

The findings, published July 24 in the journal Environmental Health Perspectives, add to growing concerns about PFAS contamination in the US food system and waterways and highlight pesticides’ “underappreciated” role in the problem, said David Andrews, a senior scientist at the Environmental Working Group and an author of the study

The study revealed that per- and polyfluoroalkyl substances (PFAS) account for 14% of all active ingredients in pesticides used in the US, including almost one-third of active ingredients approved in the last decade. Even when PFAS are not added to these products as active ingredients, pesticides are at risk for being contaminated unintentionally, primarily through PFAS leaching from the fluorinated containers in which they are stored, the study concluded.

“This is truly frightening news, because pesticides are some of the most widely dispersed pollutants in the world,” Nathan Donley, the environmental health science director at the Center for Biological Diversity and an author of the study, said in a statement. “Lacing pesticides with forever chemicals is likely burdening the next generation with more chronic diseases and impossible cleanup responsibilities.”

The authors reviewed pesticide data from the US EPA, the US Geological Survey, and the Canadian Pest Management Regulatory Agency, as well as publicly available databases, finding that PFAS-laced pesticides are regularly used nationwide on staple crops including corn, wheat, kale, spinach, apples and strawberries. PFAS are also common ingredients in flea treatments for pets and sprays to kill insects, they found.

The study comes on the heels of a petition delivered to the US Environmental Protection Agency (EPA) on Monday by the Center for Food Safety and other nonprofits asking the agency to ban PFAS in pesticides.

Regulatory concerns

PFAS have been used for decades in a wide variety of consumer products. Some of the so-called “forever chemicals” have been linked to cancers, damage to organs and the immune system, and other health problems.

One of the same qualities that make PFAS concerning to environmental and health advocates – their resistance to breaking down – also makes them attractive to pesticide manufacturers because it makes their products last longer, said Andrews.

Even as the use of PFAS in pesticides has climbed since 2012, the EPA has granted nearly all requests to bypass a requirement to assess how active ingredients affect the immune system, a “troubling” pattern that suggests health effects from these chemicals in pesticides may not be accounted for, the authors write.

“The regulations surrounding pesticides are currently outdated and ineffective, so this discovery of PFAS presence in pesticide formulations represents a new opportunity for the EPA to improve the scientific validity of pesticide risk assessment to better capture real-world exposure scenarios,” scientists from Emory University who were not involved in the study wrote in a related perspective article.

In 2021, the EPA announced its PFAS Strategic Roadmap, which outlined a strategy for cleaning up PFAS contamination and curbing the further spread of the toxic chemicals into the environment. This spring, the agency set enforceable limits for six PFAS chemicals in drinking water. Earlier this month the EPA granted a petition from environmental groups, stating that it would promptly initiate a proceeding under the Toxic Substances Control Act to address concerns about PFAS leaching from fluorinated containers.

After testing 10 pesticide products for PFAS, the agency released a memo in May 2023 stating that it did not find any PFAS in the products. The agency may have incorrectly reported some of these PFAS test results, alleges the watchdog group Public Employees for Environmental Responsibility (PEER), which said it obtained testing data through a Freedom of Information Act request that shows the EPA had actually found PFAS in the products it tested.

A spokesperson for the EPA said the agency is currently reviewing the new Environmental Health Perspectives study.

“EPA shares communities’ concerns regarding the potential risks posed by PFAS and the need for more data to better understand and address these risks in communities all across America,” said the EPA in an email. “EPA is committed to addressing the risks from PFAS from all sources, including pesticides.”

(Featured image via Unsplash+ in collaboration with Getty Images.)