Birds of prey act as sentinels to warn of forever chemicals

Birds of prey act as sentinels to warn of forever chemicals

A recent study explores the role of raptors, specifically birds of prey such as hawks and eagles, as sentinel species capable of indicating the levels of persistent "forever chemicals" in their habitats. These chemicals, known as PFAS (per- and polyfluoroalkyl substances), tend to accumulate in species that have diets rich in fish. The review, titled "Raptors as Sentinels: Unveiling the Environmental and Health Risks of PFAS Contamination," appears in the journal Toxicology Mechanisms and Methods and provides an extensive examination of current scientific data regarding PFAS, which are increasingly recognized as significant environmental pollutants.

The unique chemical structure of PFAS renders them resistant to degradation. Consequently, these substances accumulate within the body over time, leading to potential toxicity. Research suggests a correlation between PFAS exposure and various health issues, including cancer, reproductive complications, and other serious health conditions.

This study results from a collaborative effort among several international institutions, including the Sbarro Health Research Organization (SHRO), the Università Magna Graecia di Catanzaro, and the Veterinary Medicine Department at the Università degli Studi di Napoli Federico II. These institutions partnered with esteemed academic departments and research centers across Italy, such as a research team from the Foggia Local Health Authority (ASL Foggia), led by Dr. Renato Lombardi. This multidisciplinary undertaking encompasses expertise from oncology, veterinary medicine, environmental toxicology, and ecological sciences, exemplifying a thorough and interdisciplinary approach toward emerging environmental pollutants.

As apex predators situated at the top of food chains, raptors present a promising opportunity as a sentinel species for monitoring PFAS contamination through systematic tracking and analysis.

"This review marks a significant advancement in understanding the global implications of PFAS contamination from a One Health perspective," states Antonio Giordano, M.D., Ph.D., Professor at Temple University and President of SHRO. "By designating raptors as sentinel species, we reinforce the scientific basis for assessing environmental hazards and the corresponding risks to human health."

The One Health initiative, endorsed by the Italian National Institute of Health, advocates for a holistic view of human health that considers environmental influences.

"The confluence of data from wildlife studies and human epidemiology highlights the urgent need for coordinated, evidence-informed regulatory strategies," Giordano adds. "Our findings underscore the necessity for long-term, standardized biomonitoring systems capable of guiding both environmental safeguards and public health strategies on a global scale."

Utilizing global data, the authors illustrate the extensive presence of PFAS in various raptor tissues, including liver, blood, eggs, and feathers. Fish-eating species consistently demonstrate higher contaminant levels when compared to their terrestrial counterparts, indicating bioaccumulation within aquatic ecosystems. Among these substances, long-chain legacy PFAS, particularly PFOS, are observed to biomagnify significantly and frequently surpass proposed toxicological limits.

Temporal analyses depict a nuanced landscape regarding regulatory effectiveness: while PFOS levels have diminished in certain areas due to international regulations, they remain elevated in multiple populations. In parallel, newly introduced replacement PFAS compounds remain inadequately characterized, raising concerns over evolving contamination patterns rather than actual reductions in risk.

Patterns identified in the study suggest that eggs and liver tissues serve as reliable matrices for evaluating maternal transfer and long-term accumulation of PFAS, while blood and feathers provide minimally invasive options for biomonitoring. Importantly, the sublethal effects observed in raptors mirror findings from human epidemiological studies, reinforcing the relevance of a One Health framework that encompasses environmental, animal, and human health.

The authors stress the critical need for standardized, multi-matrix, and long-term biomonitoring programs that incorporate raptors alongside other complementary sentinel species to enhance the detection of contamination hotspots and refine ecological and public health risk assessments. Essential priorities involve methodological standardization, broadened monitoring initiatives in underrepresented regions, and more in-depth investigations into species-specific toxicokinetics and mixture effects.

Ultimately, the review confirms the efficacy of raptors as sentinels for PFAS contamination and highlights their role as early-warning indicators of potential health risks to humans, emphasizing the importance of coordinated global monitoring networks to inform evidence-based policies aimed at mitigation and regulation.