Legacy and emerging contaminants in meltwater of three Alpine glaciers.

Meltwater samples collected in early and late summer from three Alpine glaciers were analysed to determine the occurrence of POPs (Persistent Organic Pollutants: DDTs, HCHs and PCBs) and emerging contaminants (current used pesticides and polycyclic musk fragrances). For legacy POPs, we reconstructed a concentration time series using data from previous surveys in the same areas (starting from 2000). The results suggest a declining tendency of these compounds, probably related to the introduction of international regulations, which has led the strong use reduction and ban of these compounds. Among the analysed current used pesticides the terbuthylazine and chlorpyrifos were found in all the analysed samples. The experimental results were in line with the prediction of the OECD tool screening model, which was applied to estimate the potential of these substances to undergo regional-scale atmospheric transport processes. Temporal and spatial differences in concentrations for these compounds were related to the timing of applications, weather conditions and crop distribution along the adjacent Po River Plain. Despite model predictions, the herbicide pendimethalin was never detected, probably due to the lower use of this compound in the agricultural practices. Conversely, concentrations of polycyclic musk fragrances galaxolide and tonalide were more homogeneous both temporally and spatially, in agreement with their continuous release from emission sources.