Water quality issues: mercury and other toxic substances
BPCs, PAHs, and metals, including mercury, are part of a group of pollutants found in the environment that degrade slowly and accumulate in aquatic organisms. Scientists from Environment and Climate Change Canada’s Water Quality Monitoring and Surveillance program assess the presence of various toxic substances and their levels in selected ecosystems.
Following the adoption of regulatory measures in the 1970s, studies showed a gradual reduction in mercury contamination in fish in the Great Lakes. However, this trend reversed in the 1990s. The introduction of invasive exotic species could be the explanation.
The goal of this section is to provide scientific background information and to outline current policies, programs, and practical guidance related to mercury.
According to studies by Environment and Climate Change Canada, surface sediments in the St. Lawrence River are generally less contaminated than they were 20 years ago as a result of effluent treatment measures. Yet, concentrations of some substances have remained unchanged or are even increasing.
Technical summaries and reports
The Risk Management Strategy for Mercury provides a comprehensive and consolidated description of the Government of Canada's progress to date in managing the risks associated with mercury
This Fact Sheet is part of the Monitoring the State of the St. Lawrence River Program. Since 2005, the Carillon station has been used as a reference site in order to follow changes in aquatic contaminants such as metals and polycyclic aromatic hydrocarbons (PAH).
This fact sheet describes the spatial and temporal concentration patterns of 8 persistent toxic substances that historically have been reported to threaten or potentially threaten human health and aquatic life.
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