Chemicals found in sewage sludge that some farmers use to fertilize fields can pose significant health risks to both people and animals, according to a report released by the US Environmental Protection Agency (EPA) on Tuesday.
Exposure to food from farms that use this sludge can increase the risk of developing cancer and other health conditions, the agency said. The chemicals, known as per- and polyfluoroalkyl substances (PFAS), persist in the environment for a long time and are commonly referred to as “forever chemicals” because they break down slowly in the environment and accumulate in the human body.
The EPA’s assessment found that under certain conditions, the health risks from PFAS exposure through food are many times higher than what is considered safe. While the general food supply isn’t at immediate risk, individuals who consume large quantities of milk or beef from farms using sewage sludge are at greater risk.
PFAS, which include perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), have been used in various products like Teflon and firefighting foam. Although their use in manufacturing has largely been phased out due to health concerns, PFAS chemicals are still found in household items and drinking water systems, and are detected in the blood of nearly 98% of the US population.
According to the EPA, exposure to these chemicals is especially concerning for people who eat fish from lakes or ponds contaminated by farm runoff or drink large quantities of milk from cows grazing on pastures treated with sewage sludge. In addition, consuming pasture-raised beef or eggs from hens raised on contaminated land can also pose a risk.
The report highlights a troubling cycle of contamination, as these chemicals spread through sewage sludge and continue to pollute the environment. Dr. David Andrews, acting chief science officer for the Environmental Working Group (EWG), emphasized, “It’s quite shocking in terms of the extent that these chemicals are leading to all this downstream contamination.”
Although the EPA has not set specific limits for PFAS in food, the FDA has tested nearly 1,300 food samples since 2019, most of which were found to be PFAS-free. However, other organizations, including Consumer Reports, have reported finding gaps in government testing, noting that PFAS chemicals have been detected in milk, including some organic products.
Despite concerns, some farmers still use sewage sludge as fertilizer, and the EPA estimates that less than 1% of agricultural land in the US is affected. That 1% still covers tens of millions of acres. States like Maine have introduced bans on the use of sewage sludge in farming, but federal legislation to regulate PFAS in this context is lacking.
The EPA is calling for efforts to remove PFAS at the source, such as by eliminating their use in consumer products or requiring manufacturers to treat wastewater before it reaches treatment plants. The draft risk assessment is now open for public comment for 60 days, signaling the start of potential regulatory actions.
“This draft assessment provides important information to help inform future actions by federal and state agencies as well as steps that wastewater systems, farmers, and other stakeholders can take to protect people from PFAS exposure,” EPA Acting Administrator Jane Nishida said.
