Birds of prey act as Sentinels to warn of Forever Chemicals

A new paper investigates how raptors, or birds of prey like hawks and eagles, act as a sentinel species that can reveal the level of forever chemicals in the local environment. The forever chemicals, or PFAS, are especially high in species that eat fish. 

The review titled, “Raptors as Sentinels: Unveiling the Environmental and Health Risks of Pfas Contamination,” provides a comprehensive analysis of the current scientific data on per- and polyfluoroalkyl substances (PFAS), a persistent environmental contaminant of global concern. Due to their resistance to degradation, the body cannot break them down and they accumulate over time. Studies suggest PFAS chemicals carry risk of toxicity and they have been linked to cancer, reproductive problems, and other health issues.

The study is the result of a multidisciplinary collaboration involving multiple international institutions, including the Sbarro Health Research Organization (SHRO), the Università Magna Graecia di Catanzaro, and the Department of Veterinary Medicine of the Università degli Studi di Napoli Federico II, in partnership with several distinguished academic departments and research centers across Italy, such as the research group from the Foggia Local Health Authority (ASL Foggia) led by Dr. Renato Lombardi. This collaborative framework integrates expertise in oncology, veterinary medicine, environmental toxicology, and ecological sciences, reflecting a comprehensive and interdisciplinary approach to the study of emerging environmental contaminants.

As apex predators at the top of food chains, raptors could be a highly effective sentinel species for monitoring PFAS contamination through regular monitoring and analysis.

“This review represents a critical step forward in understanding the global implications of PFAS contamination through a One Health lens,” says Antonio Giordano, M.D., Ph.D., Professor at Temple University and President of SHRO. “By identifying raptors as a sentinel species, we strengthen the scientific foundation for assessing both the dangers to the environment as well as the risks to human health.”

One Health is a campaign backed by the Italian National Institute of Health to encourage a holistic approach to human health that takes into account the impact of environmental factors.  

“The convergence of evidence from wildlife and human epidemiology underscores the urgency of coordinated, evidence-based regulatory strategies,” Giordano continues. “Our findings highlight the necessity of long-term, standardized biomonitoring systems capable of informing both environmental protection and public health policies at an international level.”

Drawing on global data, the authors demonstrate the widespread presence of PFAS across multiple raptor tissues, including liver, blood, eggs, and feathers. Piscivorous, or fish-eating, species consistently exhibit higher contaminant burdens compared to terrestrial counterparts, reflecting amplification within aquatic ecosystems. Among these compounds, legacy long-chain PFAS, particularly PFOS, are shown to biomagnify significantly and frequently exceed proposed toxicological thresholds.

Temporal analyses reveal a complex picture of regulatory effectiveness: while PFOS levels have declined in some regions following international restrictions, they remain elevated in many populations. At the same time, emerging replacement PFAS compounds remain insufficiently characterized, raising concerns about shifting contamination profiles rather than true risk reduction. Tissue-specific patterns identified in the review indicate that eggs and liver are robust matrices for assessing maternal transfer and long-term accumulation, whereas blood and feathers offer minimally invasive alternatives for biomonitoring. Notably, sublethal effects observed in raptors parallel findings in human epidemiological studies, reinforcing the relevance of a One Health framework integrating environmental, animal, and human health.

The authors emphasize the urgent need for standardized, multi-matrix, and long-term biomonitoring programs integrating raptors with complementary sentinel species to enhance detection of contamination hotspots and improve ecological and public health risk assessment. Key priorities include methodological harmonization, expansion of monitoring efforts into underrepresented regions, and deeper investigation into species-specific toxicokinetics and mixture effects. The review ultimately confirms raptors as highly effective sentinels of PFAS contamination and underscores their value as early-warning indicators for human health risks, highlighting the importance of coordinated global monitoring networks to inform evidence-based mitigation strategies and regulatory policies.

Credits: Editorial originally published on Newswise