The U.S. Environmental Protection Agency on Tuesday issued a draft risk assessment identifying potential health risks associated with the presence of toxic per- and polyfluoroalkyl substances (PFAS), commonly known as “forever chemicals,” in biosolids used as fertilizer. The findings raise concerns about exposure to PFAS through land application of sewage sludge, surface disposal in landfills, and incineration.
The draft assessment evaluates exposure risks to PFOA and PFOS, two common PFAS chemicals, for individuals living near or consuming products from areas where biosolids have been applied. Preliminary results indicate human health risks exceeding EPA’s acceptable thresholds in certain scenarios, including farms where biosolids containing 1 part per billion (ppb) of PFAS have been applied for up to 40 years.
The EPA highlighted that risks increase proportionally with the concentration of PFAS in biosolids and the amount applied, but noted reduced risks in cases of lower PFAS levels, fewer applications, or less frequent use of biosolids.
Biosolids are the treated semi-solid byproduct of wastewater treatment, often repurposed as a nutrient-rich fertilizer. However, PFAS enters wastewater systems through household and industrial sources, accumulating in sewage sludge at treatment plants.
The EPA clarified that general food supplies are not broadly impacted by PFAS-contaminated biosolids, though localized “hot spots” and specific farming operations may pose higher risks. The U.S. Department of Agriculture and the Food and Drug Administration are monitoring PFAS levels in the food supply to address potential issues.
Acting EPA Administrator Jane Nishida emphasized the importance of addressing PFAS contamination at its source. “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,” she said.
The EPA said it has implemented measures under its PFAS Strategic Roadmap to control PFAS pollution, including increased reviews of industrial discharges, restrictions on PFAS entering commerce, and declaring PFOA and PFOS as hazardous substances under the Superfund law.
The agency says it is working to develop technology-based limits on PFAS discharges and is collaborating with state agencies to monitor PFAS in sewage sludge.
The draft risk assessment will be open for public comment for 60 days following its publication in the Federal Register. A public webinar is scheduled for January 15, 2025, to discuss the findings and address questions.
The EPA said it will use the finalized assessment to guide future risk management actions, potentially including regulating PFOA and PFOS in biosolids under the Clean Water Act.
