Grassy Narrows

Mercury Poisoning

When a person consumes a fish that is full of methyl mercury, the chemical is carried by the blood through body tissues. It concentrates in the heart, intestine, liver, and kidneys. Most of the clinical symptoms of mercury poisoning are related to brain and nerve lesions. Mercury destroys cells in the cerebellum, which regulates balance, and the cortex, which influences vision, as well as the frontal lobe, where it may cause disturbances in personality.

Swedish scientists established that abnormally high levels of mercury found in fish and wildlife were related to upstream pulp and paper plants. In 1966, the World Health Organization informed the Canadian Department of Health and Welfare that mercury could be a serious health hazard. In 1969, a University of Western Ontario study confirmed that fish taken downriver carried body burdens of mercury that were sometimes more than 40 times the standard set for export and human consumption. Federal officials did nothing. Finally, in 1970, the Ontario Minister of Energy and Resource Management ordered all companies in the province with substantial industrial mercury losses to stop discharging mercury into the environment. In that same year, Ontario banned commercial fishing on all lakes and tributaries of the English-Wabigoon river system.

One of these companies affected by the discharge ban was Dryden Chemicals Limited, a subsidiary of Reed Paper Limited. Between March 1962 and October 1975, Dryden operated a mercury cathode chlor-alkali chemical plant that produced chlorine and other chemicals for bleach in the adjacent pulp and paper mill of Reed Paper. During that period, scientists estimated that about 40,000 pounds of inorganic mercury entered the environment with about half of the amount going into the river system. In 1970, treatment systems were installed to isolate the heavy metal in the effluent. Although this resulted in a significant decline in the amount of mercury discharged, aerial emissions continued unabated. The release of mercury finally ended in 1975 when Dryden changed its technology.

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