Produce grown in home gardens around a North Carolina PFAS plant contain dangerous levels of the chemicals, new research has found, providing more evidence that food is a potentially overlooked exposure route to the compounds, especially when grown near polluters.
The study’s authors say findings point to much of the contamination resulting from air emissions, which research increasingly suggests is an underestimated source of PFAS pollution.
The peer-reviewed paper found PFAS in all 53 samples it checked that were grown in five gardens from 2013 to 2019 within several miles of the plant in Fayetteville, North Carolina, owned by the chemical giant Chemours.
“In some communities, exposure routes other than drinking water can be important and perhaps overlooked,” said Detlef Knappe, a North Carolina State University PFAS researcher and co-author.
In a statement, Chemours noted the study covered a small geographical area, and the produce was grown before the company installed some air pollution controls.
PFAS are a class of about 16,000 compounds used to make products resistant to water, stains and heat. They are called “forever chemicals” because they do not naturally break down and have been found to accumulate in humans. The chemicals are linked to cancer, birth defects, liver disease, thyroid disease, plummeting sperm counts and a range of other serious health problems.
Though regulatory and most scientific scrutiny has focused on human exposures to the chemicals in water, food is increasingly considered to be a main ingestion route.
The Food and Drug Administration (FDA) monitors for PFAS in annual testing that rarely finds the chemicals. But independent researchers have criticized the agency’s methodology, which they allege is designed to make it appear as if food is less contaminated with PFAS than it may be.
Critics have said the agency set that minimum detection level threshold unreasonably high, so even when there are potentially dangerous levels of PFAS in food, the FDA can say it did not detect any. In 2018 the agency found PFAS in 108 pieces of produce grown near North Carolina’s Chemours plant, but later changed its methodology. It then published “revised” data that showed only 36 contaminated products, and has since downplayed the risks of PFAS in food.
Knappe said the new research cannot be used to make conclusions about the broader food supply, but only about crops grown near polluters.
The levels of some of the chemicals the study found in produce present a health threat. For example, a child who eats just 10 blueberries from one of the gardens tested would consume levels of GenX, a common PFAS compound produced at the nearby Chemours plant, equivalent to drinking a liter of water with levels of the chemical above the federal limit.
Adults would have to eat about four times more blueberries to reach the same contamination levels, but the problem is likely much worse because people often eat more servings of fruits and vegetables than that estimate.
Moreover, there is no health risk data for the compounds found at the highest levels.
“We’re not able to capture the true risk … and that points to an urgent need – we need this toxicity data,” Knappe said.
Water-rich fruits and vegetables – such as strawberries, tomatoes, lettuce, blueberries and blackberries – showed higher levels than starch-rich produce, such as corn, because PFAS are attracted to water. Tree fruits, including those that are water-rich, generally showed lower levels because the chemicals have to travel further to get in the fruit.
The gardens in the study were largely watered with rainwater instead of groundwater, and higher levels were generally found downwind, suggesting air pollution is to blame.
When companies send PFAS waste into the air, it eventually rains down or settles on the ground, potentially hundreds of miles away, but in higher volumes around the pollution source. Because the chemicals can take thousands of years to break down, they accumulate in the soil, then can be taken up by food crops.
The levels generally decreased, which Knappe theorized may owe to Chemours installing pollution controls in 2013. In its statement, Chemours noted that in 2020 it installed more robust air emission controls that reduced over 99% of its emissions, but after the study’s produce was grown.
Still, testing in 2023 conducted by Knappe that was commissioned by the Guardian suggests PFAS levels in the air outside the plant remain higher than regulators and Chemours claim.
