Analysis of occurrence, bioaccumulation and molecular targets of arsenic and other selected volcanic elements in Argentinean Patagonia and Antarctic ecosystems

Abstract

In Latin America, the high proportion of arsenic (As) in many groundwaters and phreatic aquifers is related to the volcanism of the Andean Range. Nevertheless, there is still very little published research on As and other elements occurrence, and/or transference to biota in Southern regions such as Argentinean Patagonia and the South Shetland Islands in Antarctica, where there are active volcanoes and geothermal processes. Therefore, this study was aimed to describe water quality from the main rivers of Argentinean Northern Patagonia through physicochemical analysis. The Patagonian and Antarctic biota (including samples of animal, plants, algae and bacteria) was characterized through the analysis of their As and other elemental concentrations (P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Se, Br, Rb and Sr), by synchrotron radiation x-ray fluorescence spectroscopy (SRXRF). Finally, the analysis of metal and As-proteins associations in As-accumulating organisms was performed by SRXRF after sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). A wide range of metal concentration including As (up to 950 μg/L As) was found in water samples from Patagonian rivers. A hierarchical cluster analysis revealed that the elemental concentration of analysed biological samples was related to volcanic environments and their place in the trophic chain. Moreover, the results suggest that Se, Co, Cu, Br, and Cl are strong predictors of As in biota. On the other hand, As was not detected in proteins from the studied samples, suggesting biotransformation into soluble As-organic compounds. This is the first study to describe environmental pollution as a consequence of active volcanism, and its influence on water quality and elemental composition of biota in Argentinean Northern Patagonia and Antarctica.