Something’s Poisoning America’s Land

Something’s Poisoning America’s Land

For decades, farmers across America have been encouraged by the federal government to use municipal sewage sludge as fertilizer on millions of acres of farmland. This practice was touted as a win-win solution: nutrient-rich fertilizer for farmers and an eco-friendly way to keep sludge out of landfills. However, a growing body of research is revealing a hidden danger lurking in this seemingly beneficial practice - the presence of per- and polyfluoroalkyl substances, commonly known as PFAS or "forever chemicals."

The PFAS Crisis Unfolds

PFAS are a group of synthetic chemicals used in a wide range of consumer products, from non-stick cookware to firefighting foam. Their unique properties, including resistance to heat, water, and oil, have made them ubiquitous in modern life. However, these same properties also make PFAS extremely persistent in the environment, earning them the moniker "forever chemicals."

Recent investigations have uncovered alarming levels of PFAS contamination on farmland across the United States. The chemicals are being detected in soil, water, and even in the plants and animals raised on these farms. This contamination is linked directly to the use of sewage sludge as fertilizer.

The Sewage Sludge Connection

Municipal sewage treatment plants receive wastewater from homes, businesses, and industries. While these plants are designed to remove many contaminants, they are not equipped to filter out PFAS. As a result, these chemicals concentrate in the solid waste, or sludge, left over from the treatment process.

When this sludge is spread on farmland as fertilizer, it introduces PFAS into the agricultural ecosystem. The chemicals can then be taken up by crops, consumed by livestock, and leach into groundwater, potentially contaminating drinking water sources.

A National Scale Problem

The extent of farmland contamination is only now becoming apparent. Investigations in several states have revealed concerning levels of PFAS:

In Michigan, officials shut down one farm after finding high concentrations of PFAS in the soil and cattle. The state has now prohibited the property from ever being used for agriculture again.

A cattle barn in Michigan, now empty, after the land and the animals were found to be contaminated. A cattle barn in Michigan, now empty, after the land and the animals were found to be contaminated – Emily Elconin for The New York Times

Maine has taken the most aggressive stance, banning the use of sewage sludge on agricultural fields entirely. The state has also begun systematically testing farms, finding contamination on at least 68 of the first 100 sites checked.

In Texas, ranchers have filed lawsuits blaming PFAS-contaminated sludge fertilizer for the deaths of cattle, horses, and fish on their properties.

A farm family who lost their cattle to PFAS A farm family who lost their cattle to PFAS – Jordan Vonderhaar for The New York Times

Health and Economic Impacts

The health implications of this contamination are significant. PFAS have been linked to a range of health issues, including cancer, thyroid disorders, and developmental delays in children. For farmers and ranchers, the discovery of PFAS on their land can be economically devastating. Many are forced to stop selling their products, effectively losing their livelihoods overnight.

Regulatory Challenges

At the center of this crisis is the Environmental Protection Agency (EPA), which for decades has encouraged the use of sewage as fertilizer. While the EPA regulates pathogens and heavy metals in sewage fertilizer, it does not currently regulate PFAS content. The agency is now studying the risks posed by PFAS in sludge fertilizer to determine if new rules are necessary.

However, this process is slow, and many argue that action is needed immediately. Some states, like Maine, have taken matters into their own hands by implementing bans and testing programs.

The Scale of the Problem

The true extent of PFAS contamination in US agriculture is staggering. According to industry estimates, toxic sewage sludge containing PFAS is used to fertilize approximately 70 million acres of US farmland - equivalent to about one-fifth of all agricultural land in the country. This widespread use creates a direct pathway for these "forever chemicals" to enter our food system through contaminated crops and livestock.

Map of US tap water containing PFAS

The situation is made even more alarming by the EPA's recent acknowledgment that there is no safe level of PFAS for human consumption. Despite this, the agency continues to promote the use of PFAS-laden biosolids on farmland, creating a paradoxical situation where practices that potentially harm public health are still being encouraged.

Biodegradation: A Potential Solution?

Given the persistence of PFAS in the environment and the challenges of removing them through conventional means, researchers are increasingly looking to biodegradation as a potential solution. A comprehensive review of PFAS biodegradation research reveals both promising developments and significant challenges.

Key findings from the biodegradation research include:

  • Microbial Diversity: Both bacterial and fungal species have shown effectiveness in degrading various PFAS compounds. Pseudomonas sp., in particular, has emerged as a promising candidate for PFAS biodegradation.
  • Degradation Pathways: PFAS biodegradation can occur through two main pathways - with or without the cleavage of the carbon-fluorine (C-F) bond. The C-F bond is exceptionally strong, making it resistant to degradation, but some microorganisms have shown the ability to break this bond.
  • Efficiency Factors: The presence of competing chemicals or co-substrates can significantly affect biodegradation efficiency. Understanding these interactions is crucial for developing effective bioremediation strategies.
  • Incomplete Degradation: While some microorganisms can partially degrade PFAS, achieving complete mineralization remains a significant challenge. Often, the degradation process results in shorter-chain PFAS compounds, which may still pose environmental risks.
  • Environmental Conditions: The effectiveness of PFAS biodegradation can vary greatly depending on environmental factors such as temperature, pH, and the presence of other contaminants.

Degradation of PFAS by microbes

Despite these challenges, biodegradation offers several advantages over physical and chemical treatment methods, including lower costs and less disruption to soil and water environments. However, researchers emphasize that novel biological or combined methods are needed to achieve complete PFAS degradation.

The Path Forward

The widespread contamination of US farmland with PFAS presents a complex challenge that threatens the health of our food system and, by extension, public health. While biodegradation offers a promising avenue for addressing this issue, it's clear that a multi-faceted approach will be necessary.

This approach should include:

  • Immediate action to stop the further application of PFAS-contaminated biosolids on farmland.
  • Comprehensive testing of agricultural land, crops, and livestock to understand the full extent of contamination.
  • Development of remediation strategies, including advanced biodegradation techniques, to clean up contaminated land.
  • Support for affected farmers, including financial assistance and guidance on alternative farming practices.
  • Stricter regulation of PFAS use in industry to prevent these chemicals from entering the waste stream in the first place.
  • Increased funding for research into PFAS alternatives and more effective degradation methods.

The challenge of PFAS contamination in our farmland is a stark reminder of the long-lasting impacts of our chemical use. As we work to address this issue, it's crucial that we prioritize not just the disposal of our waste, but the long-term health of our agricultural lands, the safety of our food supply, and ultimately, the well-being of current and future generations. The deck may be stacked against a healthy food system now, but with concerted effort and innovative solutions, we can work towards a cleaner, safer agricultural future.

Filters that remove PFAS from water

Some top-rated filters that remove PFAS from water include:

References