Heavy metals in hair of wild canids from the Brazilian Cerrado

In this study, we aimed to assess whether free-ranging wild canids are exposed to heavy metals in one of the most developed and populated regions of Brazil. Hair of 26 wild canids (maned wolves Chrysocyon brachyurus, crab-eating foxes Cerdocyon thous, and hoary foxes Lycalopex vetulus) from the Cerrado biome in Southeast Brazil were analyzed by spectrophotometry to detect cadmium, chromium, and lead, and also the essential copper, iron, manganese, and zinc traces. All samples showed traces of copper, iron, manganese, and zinc. Non-essential lead was detected in 57% (2.35 ± 0.99 mg/kg), and chromium in 88% (2.98 ± 1.56 mg/kg) of samples. Cadmium traces (detection limit 0.8 mg/kg) were not found. Crab-eating foxes had more copper, iron, and manganese in hair than maned wolves. Correlations among element levels differed between maned wolves and crab-eating foxes. Concentrations of chromium and lead were outstandingly higher than in wild canids from other areas. Addressing the causes of such levels and the impacts of the heavy metal pollution in Neotropical ecosystems is urgent for animal health and conservation purposes. We argue that heavy metal pollution should be considered as dangerous threats to wildlife health in Brazil and recommend hair sampling as a biomonitoring tool for heavy metals in Neotropical terrestrial mammals.