Mesocarnivores as Sentinels of Environmental Metal(Loid) Exposure in a Mediterranean Protected Area

Metal(loid)s pose an ecological concern due to their persistence, toxicity, and potential for bioaccumulation in terrestrial ecosystems. In this study, concentrations of 14 elements, including As, Cd, and Pb, were determined in liver and kidney tissues from three mesocarnivore species collected as roadkill in and around Sierra de Aracena and Picos de Aroche Natural Park (SW Spain) between 2015 and 2018. Accumulation patterns differed among species and tissues. The Eurasian badger (Meles meles) showed the highest overall burdens, particularly for Cd in the kidney, consistent with greater long-term exposure. The stone marten (Martes foina) showed the lowest concentrations, whereas the Egyptian mongoose (Herpestes ichneumon) displayed intermediate values. Essential elements were generally more concentrated in liver than kidney. These findings indicate that wild mesocarnivores, especially Eurasian badgers, may be useful bioindicators of metal(loid) exposure; screening comparisons found no main Cd or Hg reference-value exceedances, although three badgers had renal Cd within an experimental effect range.