Bioaccumulation of Heavy Metals (17 Elements) in the Liver and Kidneys of the Least Weasel (Mustela nivalis L.) from Agricultural Areas of Central Europe

In this study, we investigated the bioaccumulation of 17 heavy metals—titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, selenium, molybdenum, antimony, cadmium, tin, mercury, and lead—in the liver and kidney tissues of the least weasel, based on samples (n = 129) collected from adjacent intensive agricultural environments in Hungary and Austria. To explore the structure of the bioaccumulation data, principal component analysis (PCA) was performed. The PCA score plot based on national-level elemental profiles revealed no differentiation between Austria and Hungary. In contrast, a clear and unambiguous distinction was observed between the two examined tissues within individuals for Ti, Mn, Fe, Co, Zn, Se, Mo, Cd, and Hg (p < 0.001), as well as for Pb (p < 0.05). The biological relevance of the accumulation results was adjusted using the MCID approach. As heavy metal accumulation in the least weasel has not yet been investigated, our results could only be compared with concentrations reported for predatory mammals occurring in similar habitats. Based on the relevant literature, we highlight predominantly anthropogenic exposure pathways affecting agroecosystems—organic and mineral fertilizers, plant protection products, wastewater, and fossil fuels—which underscore the necessity of regular biomonitoring studies in agricultural landscapes.