Sewage sludge, a byproduct of wastewater treatment, has long been used by some farmers as a fertilizer to enrich soils. However, recent findings by the U.S. Environmental Protection Agency (EPA) have raised concerns about the health risks associated with this practice. The sludge contains harmful chemicals known as per- and polyfluoroalkyl substances (PFAS), often referred to as “forever chemicals,” which can persist in both the environment and the human body for extended periods.
PFAS, including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), are synthetic chemicals used for their water- and oil-repellent properties. These chemicals have been utilized in a range of household products such as nonstick cookware (e.g., Teflon) and firefighting foam. Although their use has declined due to growing health concerns, they are still present in everyday items and in drinking water systems. Studies have found that nearly 98% of the U.S. population carries trace amounts of these chemicals in their blood.
The recent EPA report highlights the potential health risks posed by the use of sewage sludge in agriculture. These chemicals are particularly concerning because they accumulate over time, meaning even small amounts can lead to significant exposure. The EPA’s draft risk assessment warns that individuals consuming food from farms using this sludge may be at a higher risk of developing various health issues, including cancer. People who consume large quantities of milk, beef, or fish from farms contaminated by sewage sludge are particularly vulnerable.
For instance, individuals who drink a quart of milk daily or consume pasture-raised beef from land treated with sewage sludge could be exposed to PFAS at levels far above what the EPA deems acceptable. Additionally, fish from lakes or ponds affected by farm runoff may carry PFAS concentrations harmful to those who eat fish frequently.
The danger lies in the persistence of PFAS in the environment. These chemicals do not break down easily, and as a result, they can travel through soil and water, contaminating far-reaching ecosystems. The chemicals can enter the food chain when livestock graze on pasture treated with sludge or when crops are fertilized with contaminated sludge.
While the EPA has not set specific limits for PFAS in food, the agency has conducted extensive testing on food products since 2019. According to the U.S. Food and Drug Administration, most samples tested were free from detectable levels of PFAS, though consumer organizations such as Consumer Reports have found PFAS contamination in some milk products, including those labeled as organic. Organic farms typically avoid using sewage sludge, yet contamination can still occur through environmental pathways.
The widespread presence of PFAS in the environment underscores the need for more stringent regulation. Although federal guidelines set limits on some metals in sewage sludge, PFAS remains unregulated. In the absence of federal action, individual states have begun implementing their own measures. For example, Maine has introduced a ban on the use of sewage sludge on agricultural land to protect its residents from these harmful chemicals.
The EPA’s findings stress the importance of addressing PFAS contamination at its source. Measures such as eliminating PFAS from consumer products or requiring manufacturers to treat polluted wastewater before it enters sewage treatment plants could help reduce the levels of these chemicals in the environment. Moreover, government intervention at both the federal and state levels is crucial to mitigating the impact of PFAS on public health.
To protect themselves, consumers can use water filters to reduce PFAS exposure in drinking water and stay informed about local water testing results. However, these measures are only part of the solution. As Dr. David Andrews from the Environmental Working Group notes, efforts must be made to stop the use of PFAS in industries and ensure that the regulatory framework effectively addresses this growing contamination issue.
The EPA’s draft risk assessment is open for public comment for 60 days, and the agency emphasizes the need for collaboration across all sectors to reduce the risks associated with PFAS contamination. By working together, it may be possible to protect both human health and the environment from the harmful effects of these “forever chemicals.”
