In situ measurements of metal speciation in the Canadian Arctic

点击翻译按钮获取中文摘要

Trace metals in the environment may provide benefits or risks to aquatic life and humans. They can arise naturally, or result partly or wholly from man-made pollution. However it is no longer adequate to consider only the total metal concentration to assess risk/benefit. Rather, it is necessary to determine the physicochemical forms of toxic elements (i.e. speciation) because different forms of the same metal can range from essential to innocuous to strongly toxic. In this program, a newly developed time-integrated passive sampling system for monitoring metal speciation, the diffusive gradients in thin films technique (DGT), will be developed and optimized for the arctic conditions. Our 5-year field work effort will focus on the Churchill estuary (Hudson Bay, Manitoba) and in Cambridge Bay near the Canadian High Arctic Research Station (CHARS) during the transition spring freshet/base flow and under ice bloom period respectively. The linkages between dissolved organic matter quality and free/labile metal concentration measured by DGT will be investigated. This research program will allow us to better understand the temporal variations in metal speciation in arctic aquatic systems and contribute in HQP formation in polar sciences.