Forever chemicals in sewage-based fertilizer spread on pastures can increase cancer risks for people who consume milk, beef, eggs and other products from those farms, with some risks potentially far exceeding acceptable levels, federal officials said Tuesday.
The risks will vary from farm to farm, depending on fertilizer makeup and use, but a draft report from the U.S. Environmental Protection Agency says the risk of consuming milk, beef or eggs from cows or hens raised on sludge-fertilized pastures can exceed safe thresholds by “several orders of magnitude.”
“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,” acting EPA Administrator Jane Nishida said in a written statement.
The draft risk assessment “confirms what Maine already knew” since before 2022, when it became the first state in the nation to ban fertilizers and compost derived from sludge containing so-called forever chemicals, said Deputy Commissioner David Madore of the Maine Department of Environmental Protection.
A multi-year state investigation has found unsafe PFAS levels at 70 farms from sludge-based fertilizer dating back to the 1970s. This state-permitted practice was promoted as a free source of fertilizer and, when treated for heavy metals and bacteria, a safe way to recycle human waste.
The Maine Organic Farmers and Gardeners Association sued the EPA in 2024 for failing to regulate the spread of perfluoroalkyl and polyfluoroalkyl substances, or PFAS, saying a state-by-state approach puts Maine farmers at a competitive disadvantage and Maine food consumers at risk.
MOFGA created a PFAS relief fund that has handed out more than $1.5 million in direct support to more than 50 affected farm families. Seven MOFGA-certified operations had to pause sales due to the severity of PFAS contamination, and two had to shut down entirely.
Under the Clean Water Act, the EPA is supposed to identify pollutants in biosolids every two years. Identifying forever chemicals as harmful is the first step in setting limits on industrial discharges — something the Biden administration had pledged to consider.
The draft EPA risk assessment, which will be subject to public comment for 60 days, is based on a single instance of exposure to sludge, but most people will face multiple exposures that will drive up those risks, especially the farmers that live and work on the contaminated farms.
People are exposed to forever chemicals through a broad range of common household products, such as nonstick pans, makeup and waterproof clothing. Farmers can be exposed through consuming eggs, milk and meat from pasture-raised hens and cows and drinking water from on-site wells.
Eating fish from a lake or stream tainted by field runoff is another high risk, the report concluded.
The cancer risk levels associated with an adult drinking 32 ounces per day of contaminated milk can exceed 1 in 1,000, according to the draft assessment. The cancer risk for an adult who eats one serving per day of certain fruits and vegetables grown in sludge-amended soil can exceed 1 in 100,000.
The agency emphasized that these risk calculations are conservative estimates because they are based on models that assume low concentrations of forever chemicals in the sludge, average exposure conditions to a single sludge source, and don’t account for exposure to PFAS in retail products.
Defend Our Health, a Portland-area environmental nonprofit that played a key role in passing the Maine sludge ban, was pleased with the draft assessment, noting the PFAS toxicity levels proposed by EPA were more protective than what Maine had in place before it banned sludge spreading.
Maine’s old limits — 2.5 parts per billion for perfluorooctanoic acid (PFOA) and 5.2 parts per billion for perfluorooctane sulfonic acid (PFOS) — are higher than EPA’s suggested 1 part per billion limit for PFOA and PFOS sludge-derived fertilizer, said Adam Nordell, a Defend Our Health campaign manager.
But Nordell, who closed his Unity farm in 2021 after discovering high levels of PFAS contamination from sludge applications applied two owners before him, said Maine farmers face multiple, overlapping PFAS exposure risks all at once, from the well water they drink to the dust kicked up by their tractors.
“The (proposed limits) could be even more health protective if they considered the compounding ways farming communities are interacting with these chemicals, and if they were designed to protect the most vulnerable people who consume the different foods at the highest rates,” Nordell said.
Environmental Working Group, an advocacy group that supports tighter PFAS regulation, urged Congress on Tuesday to limit industrial discharges of PFAS, make chemical manufacturers pay for the cleanup, and direct the Food and Drug Administration to set limits for PFAS in food.
“Congress must ensure these farmers aren’t burdened with the costs of fixing this problem — that responsibility should ultimately rest with the polluters,” said David Andrews, Environmental Working Group’s acting chief science officer.
There are currently no state or federal PFAS limits or pretreatment standards for industrial or sewage discharges, Madore said. EPA is developing pretreatment standards for some categories of waste, like landfill leachate, that Maine will implement once they are final, he said.
The chemicals used to make many common household and industrial products resistant to heat, water and grease are almost everywhere: in animals from pandas to polar bears, in the rain, even in our blood. They eventually wind up in our public water supplies and many of our ponds, lakes, rivers and oceans.
Even trace amounts of some PFAS can be dangerous to humans, with exposure to high levels of certain PFAS linked to decreased fertility and increased high blood pressure in pregnant women, developmental delays in children and low birth weight, increased risk of some cancers and weakened immune systems.
Send questions/comments to the editors.
We invite you to add your comments. We encourage a thoughtful exchange of ideas and information on this website. By joining the conversation, you are agreeing to our commenting policy and terms of use. More information is found on our FAQs. You can modify your screen name here.
Comments are managed by our staff during regular business hours Monday through Friday as well as limited hours on Saturday and Sunday. Comments held for moderation outside of those hours may take longer to approve.
Join the Conversation
Please sign into your Press Herald account to participate in conversations below. If you do not have an account, you can register or subscribe. Questions? Please see our FAQs.