Wednesday May 5, 2010 7:00 PM – USGS headquarters (Reston, VA)
Mercury Contamination of the Environment: From Me to Shining Sea
Dr. David Krabbenhoft
(PDF of Flyer 864 KB)
This presentation will summarize over two decades of scientific advancements that now allow us to predict reliably which aquatic ecosystems will contain greater or lesser mercury-contamination levels, and to inform decision makers on effective strategies for reducing the deleterious impacts of mercury on our environment.The potential consequences of mercury contamination of the environment were first recognized in Japan in the 1950s, where human consumers of contaminated fish were severely poisoned. These and other tragic incidents prompted regulations such as the Clean Water Act that resulted in significant reductions of direct releases of mercury into surface waters of the US. Mercury levels in fish in affected waters typically declined during the years after point-source loads declined, leading to a widespread perception that the “mercury problem” had been solved. Since about 1985, however, widespread mercury contamination of aquatic food webs has become evident in systems remote from obvious anthropogenic mercury sources. Investigations at these sites have shown that in most cases atmospheric mercury emissions, long-range transport, and subsequent deposition are responsible for the global appearance of mercury-contaminated food webs. In some cases, mercury concentrations in fish from seemingly remote locations have equaled or exceeded those from waters heavily contaminated by direct industrial discharges.