A new study by engineering firm Arcadis has revealed that earthworms are likely the primary source of high PFAS levels found in eggs from backyard chickens. The research, commissioned by four local authorities near the Chemours factory in Dordrecht, the Netherlands, aimed to identify potential sources of these "forever chemicals" in the area.
Initially, investigators ruled out soil as the main culprit for the chemical pollution. After examining various potential sources, including chicken feed, medicine, and water, the team concluded that earthworms - a staple in free-range hens' diets - were largely responsible for the elevated PFAS concentrations.
The findings suggest that the high levels of PFAS in earthworms could account for most of the contamination found in eggs, though other sources cannot be entirely ruled out. This discovery has prompted the Dutch public health institute RIVM to expand the research project nationwide.
Interestingly, the type of PFAS predominantly found in the eggs was PFOS (Perfluorooctanesulfonic acid), which researchers believe has not been used in Chemours' production process. This unexpected chemical fingerprint adds another layer of complexity to the ongoing PFAS contamination issue in the Netherlands.
The study began in October 2023 following recommendations from regional health bodies and Wageningen University, after high PFAS concentrations were detected in eggs from hens kept near the factory. These findings have further fueled concerns about PFAS contamination in the country, which has already impacted drinking water quality and prompted warnings about consuming locally caught fish and shellfish.
As the RIVM expands its investigation into PFAS in the Dutch environment through 2026, the results of this study may have far-reaching implications for backyard chicken keepers and local food production. The research underscores the need for continued monitoring and mitigation efforts to address PFAS contamination in the environment.
