Sources, trends, implications and remediation of mercury contamination of lakes in remote areas of Canada

The long-range atmospheric transport and deposition of mercury (Hg) into la kes has become a subject of increasing interest. In Canada today, the main sources of anthropogenic, atmospheric Hg are considered to be power station s and waste incinerators in the United States and Europe. Increases in depo sition of Hg have been recorded in lake sediment cores from many parts of C anada. Where Hg input to lakes from local sources in Canada has been reduce d, concentrations in lake sediments and lake biota have declined. However, in many remote lake, fish consumption advisories are still in effect for Hg . Debate continues over the sources of this mercury, whether lone-range ant hropogenic, atmospheric or natural. Many remedial actions have been taken i n the past, and continue to be taken, to reduce Hg releases to the environm ent in Canada.