PFAS exposure linked to altered innate immune biomarkers in a sentinel apex predator, the bald eagle (Haliaeetus leucocephalus).

PFAS exposure is linked to altered innate immune biomarkers in bald eagle nestlings, with significant negative associations between some long-chain PFAS and complement-mediated lysis.

• Why it matters: Understanding how PFAS affects wildlife health is crucial because these persistent contaminants bioaccumulate in food webs, yet their biological impacts on apex predators like bald eagles remain poorly characterized.
• What they did: The study analyzed blood plasma from bald eagle nestlings across Wisconsin, measuring PFAS levels and immune biomarkers such as IgY, complement activity, and WBC counts, using models that account for non-linear exposure-response relationships.
• The result: Findings show that certain PFAS are associated with decreased complement activity and shifts in leukocyte profiles, indicating that environmentally relevant PFAS concentrations may influence immune function in this sentinel species.