Yale researchers have developed a low-cost PFAS remediation method that could restore contaminated farmland while removing carbon dioxide from the atmosphere.
Agricultural land contaminated with per- and polyfluoroalkyl substances (PFAS) could soon be restored using a significantly cheaper and more sustainable approach developed by researchers at Yale University.
The proposed PFAS remediation method is designed to help farmers reclaim polluted land while simultaneously capturing carbon dioxide from the atmosphere.
The research, published in the Proceedings of the National Academy of Sciences, addresses one of the biggest environmental challenges facing agriculture.
Millions of hectares of farmland have been contaminated by PFAS, often referred to as “forever chemicals”, leaving many farms unable to produce food safely and facing remediation costs that are beyond reach.
According to the research team, the new process could reduce remediation costs dramatically while allowing contaminated land to remain in agricultural use throughout treatment. The approach also improves soil health and contributes to climate change mitigation through carbon removal.
Growing challenge of PFAS contamination
PFAS are a large group of synthetic chemicals that have been widely used in consumer products and industrial applications for decades due to their resistance to heat, water and grease.
Their persistence means they do not readily break down in the environment, allowing them to accumulate in soil, groundwater and living organisms.
In many agricultural regions, PFAS contamination has been linked to the historic use of sewage sludge as fertiliser. Wastewater containing PFAS entered treatment systems before being processed into biosolids that were spread on farmland.
As scientists began to understand the health risks associated with these chemicals, including links to certain cancers, fertility problems and immune system disorders, concerns over contaminated agricultural land intensified.
Researchers estimate that around 1.2 million hectares of cropland in the United States alone may be significantly affected by PFAS contamination.
A more affordable approach to PFAS remediation
Existing PFAS remediation methods are often prohibitively expensive. Removing contaminated soil or treating it with high-temperature thermal processes can cost between £800,000 and £1.6m per hectare, making large-scale restoration financially unrealistic.
The Yale-led team has instead developed a process based on two of the best-known PFAS compounds: perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).
The first stage involves applying a thin layer of crushed alkaline rock to contaminated fields. This increases soil pH, encouraging plants growing on the land to absorb PFOS more efficiently.
Once harvested, the plant material is converted into biochar through controlled heating. This process destroys both PFOS and PFOA while producing biochar that can contribute to long-term carbon storage.
Researchers estimate the method would cost approximately £1,460 per hectare each year. Repeated annually over up to 20 years, the total PFAS remediation cost would exceed £29,000 per hectare, including compensation for lost farm income during treatment.
This represents a substantial reduction compared with current remediation techniques.
Restoring farmland while removing carbon
Beyond reducing contamination, the proposed system delivers additional environmental benefits. The crushed rock enhances natural weathering processes that capture atmospheric carbon dioxide, while the production of biochar locks carbon into a stable form.
The researchers estimate that, if implemented nationally across contaminated farmland, the approach could remove around 10.5 million metric tonnes of carbon dioxide from the atmosphere every year.
Unlike many existing remediation methods that take farmland out of production, the new system enables land to continue serving an agricultural purpose during restoration, offering a more practical pathway for affected farmers.
Supporting long-term agricultural resilience
While further validation and large-scale deployment will be needed, the research highlights a promising direction for PFAS remediation that combines environmental restoration with climate action.
By lowering costs, improving soil health and allowing continued agricultural use, the approach could provide farmers with a practical way to recover contaminated land while addressing one of the most persistent pollution challenges facing modern agriculture.
