Evaluation of the distribution of mercury in lakes in Nova Scotia and Newfoundland (Canada)

Distribution and sources of total mercury were evaluated in sixty lakes in Nova Scotia and Newfoundland. The concentration of total mercury in the lake water samples was similar to those observed in other natural water systems. Mercury concentration in the lakes correlated positively with aluminum, total organic carbon, color, iron, and total nitrogens and inversely with pH and sulfate. The lake water quality parameters were placed in three distinct groups using principal component and cluster analyses. The chemical constituents in the groups were identified as being associated with lake watershed geology, atmospheric washouts of long range transported acidic pollutants and dust particles, and a marine source. Stepwise multiple regression applied to the variables in the same principal component and strongly correlating with mercury identified total organic carbon, total nitrogen, pH, aluminum and iron as the best predictors for total mercury concentrations in the study lakes.