Atlas of Contaminated Sites

Notable case, Dryden / Grassy Narrows First Nation, Ontario, Canada

Grassy Narrows (English–Wabigoon River)

Asubpeeschoseewagong

Between 1962 and 1970 a chlor-alkali plant at Dryden discharged more than 9 tonnes of mercury into the Wabigoon River. The fish, the basis of the diet and economy of the Grassy Narrows and Wabaseemoong First Nations, are still contaminated.

Status
Not addressed
Activity
1962–1970
People affected
1,608 (2023)2
Media
sediment, surface water, living organisms
Kind of site
chemical works, pulp and paper
  1. Area. The Wabigoon–English river system below Dryden; Grassy Narrows lies about 100 km downstream of the discharge. The coordinates mark the community.
  2. People affected. Registered population of Grassy Narrows First Nation (October 2023); Wabaseemoong (Whitedog) First Nation is affected too.

Contaminants

Metals

Status

Not addressed

The mercury has never been removed from the river. In 2017 Ontario pledged C$85 million for cleanup and in 2020 the federal government agreed to build a C$20 million care centre; concern that dredging would remobilise the mercury has so far held back work on the sediment.

Story

The Dryden Chemical Company, owned like the nearby paper mill by Britain's Reed International, started a chlor-alkali plant in 1962 to supply chemicals for bleaching paper. Until 1970 it discharged more than 9,000 kg of mercury into the Wabigoon–English river system; emissions to air went on until 1975 and the plant closed in 1976.

Once the contamination was found, the commercial fishery was closed: unemployment at Grassy Narrows reached about 90%, and work for fishing guides collapsed as well. In 1975 the Japanese physician Masazumi Harada, a specialist in Minamata disease, found mercury levels in residents more than three times the Canadian limit at Grassy Narrows and seven times at Whitedog. In 1985 a settlement of about $17 million set up the Mercury Disability Board. In 2016 a report pointed to mercury containers buried near the river.

Timeline

  1. 1962Dryden chlor-alkali plant starts up.
  2. 1970Mercury discharges to the river end; commercial fishery closed.
  3. 1975Masazumi Harada's first survey.
  4. 1985Compensation settlement and Mercury Disability Board.
  5. 2017Ontario pledges C$85 million for cleanup.
  6. 2020Federal agreement on a care centre for people with mercury poisoning.

Health

Harada's studies (1975, 2004) documented exposure and symptoms consistent with Minamata disease: sensory disturbance, narrowing of the visual field, tremor, ataxia. A 2014 study reported numbness, hearing loss, headaches and cramps; a 2023 study described intergenerational effects on young people's mental health. Walleye from the river carry mercury at 13–15 times the recommended levels (Wikipedia).

From the literature

Species that acted on one of this site's contaminants in at least one study. The list is automatic and takes no account of this site's soil, concentrations or climate.

Plants

Fungi

Sources

  1. Ontario Minamata disease, Wikipedia, 2026
  2. Asubpeeschoseewagong First Nation, Wikipedia, 2026

Draft compiled from public sources, not yet reviewed.