Maine’s groundbreaking study on PFAS contamination in livestock feed crops sparks urgent response

USA – The Maine Center for Disease Control and Prevention (Maine CDC) has published a critical study on the contamination of livestock feed crops by per- and poly-fluoroalkyl substances (PFAS), also known as “forever chemicals.” 

This research, featured in the Journal of Agricultural and Food Chemistry, provides foundational insights into how PFAS transfers from soil to grass crops grown as livestock feed, marking a new chapter addressing contamination risks in food production.

PFAS, a class of chemicals that includes over 5,000 compounds, are known for their persistence in the environment and their resistance to degradation. 

These chemicals can infiltrate crops and accumulate in animals consuming contaminated feed, affecting the broader food chain, including products like milk and beef. 

The Maine CDC study was conducted on a dairy farm whose soils had historically been exposed to PFAS through the application of wastewater sludge or biosolids. 

Researchers focused on perfluorooctanesulfonic acid (PFOS)—one of the most problematic PFAS compounds due to its tendency to accumulate in plants and animals over time.

The study involved sampling soils and grass across multiple fields over three years to measure PFOS levels and track the extent of plant uptake. 

Results revealed that PFOS levels varied significantly across fields, with a tenfold difference even within the same farm. Interestingly, this variation was not tied to typical soil properties like pH or organic matter. 

Instead, higher PFOS levels correlated with precursor PFAS compounds in the soil, which can convert into PFOS under environmental conditions. 

Moreover, grass harvested later in the summer showed nearly double the PFOS contamination compared to earlier cuts, indicating that harvest timing may influence PFOS levels in forage crops.

“This study fills a crucial data gap, allowing us to predict better the movement of PFOS from contaminated soil to forage crops,” said Tom Simones, Assistant State Toxicologist at the Maine CDC. 

“With this knowledge, we can guide farm management decisions more effectively to help farms mitigate PFAS risks and continue safe operations.”

The findings already inform Maine’s regulatory response to PFAS contamination in agriculture. 

The data are shaping best practices for farmers, especially those with PFAS-impacted soils, to reduce PFOS exposure and limit its accumulation in animal products. 

Strategies may include optimising harvesting schedules and employing additional soil management techniques to reduce plant uptake of PFAS.

Looking forward, the University of Maine has launched a series of collaborative studies that build on the Maine CDC’s findings. 

These upcoming studies will further investigate how PFAS uptake varies between feed crops, such as corn, a staple in livestock diets. 

The team aims to uncover additional factors influencing PFAS absorption by forage crops and to develop farm management protocols for PFAS mitigation. 

Collaborators from the Maine Department of Agriculture, Conservation and Forestry, the U.S. Food and Drug Administration (FDA), and the Maine Organic Farmers and Gardeners Association, along with support from the Maine Department of Environmental Protection and the Broadreach Foundation, also contribute to these efforts.

The broader scientific and agricultural communities closely monitor these developments, as PFAS contamination remains a nationwide issue with severe implications for public health.

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