Tracing the footprints of Arctic pollution: Spatial variations in toxic and essential elements in Svalbard reindeer (Rangifer tarandus platyrhynchus) faeces

Using HR-ICP-MS, we obtained the concentration of 55 elements in Svalbard reindeer (Rangifer tarandus platyrhynchus) faeces (n=96) and soil (n=9) from two locations on Nordenskiöld land, Svalbard. The main aim was to compare the elemental composition and concentrations in faeces from the two reindeer populations to investigate whether Svalbard reindeer were exposed to toxic elements and to evaluate whether reindeer inhabiting pristine areas have a different faecal elemental composition as compared to reindeer living in areas more influenced by anthropogenic activities. Soil samples were analysed to study the geochemical background differences between the two sites. All faecal (freeze-dried) and soil (air-dried) samples were digested in nitric acid using a high-pressure microwave system prior to ICP-MS analysis. The reported data is provided in dry weight. Along with the faecal elemental composition data, we provide information on the sampling coordinates, the distance to the nearest shoreline, the year of sampling, the gender of the sampled individual and the estimated age of the sampled individual. Along with the soil elemental composition data, we provide the sampling coordinates, year of sampling and which soil horizon was sampled (in this case, all of the soil samples were topsoil samples (upper 10 cm layer). There were significant differences in several elemental concentrations between the two sites. Elements of geogenic origin (e.g., Al, Cu and Fe) were found at higher levels in faeces from Adventdalen. In comparison, levels of Ca, Se and the toxic elements Cd and Pb were higher in faecal samples from the Nordenskiöld coast. The significantly higher levels of faecal Cd and Pb at Nordenskiöld coast may be due to marine input, dietary differences between the populations, or possible anthropogenic influence from the nearby settlement of Barentsburg (located 15 km away). There was, however, a decoupling in elemental composition between faecal and soil samples, meaning that we did not find the same trends between the sites in the two matrices. This could derive from a selective plant uptake of elements from the surrounding soil.