Decades of mercury exposure have been linked to high teenage suicide rates in a Canadian Indigenous community, according to the latest study to highlight the disastrous legacy of environmental poisoning.

Researchers studied three generations of mothers and children from Grassy Narrows, Ontario, Canada, and concluded that sustained exposure to mercury contributed to a suicide rate three times higher than any other First Nations community - which is already far higher than the country's general population.

Read more: Canada to pay $31 billion to compensate Indigenous families

For over a decade after 1963, when a paper manufacturer dumped more than 20,000 pounds of mercury into the Wabigoon and English river systems, Grassy Narrows was the location of mercury dumping. Fish became contaminated and the dumping affected more than 150 miles of watershed. A single gram of mercury is enough to render every fish within a 20-hectare radius unfit for food — but the dumping at Grassy Narrows was 9 million times greater.

Before the incident, the community did not see any suicide attempts, however afterward the rate outdid that of any other First Nations community in Canada. Over 40% of the teenagers in the community attempted suicide according to mothers in the community.

The study was published in the Environmental Health Perspective journal and examined 80 mothers and 162 children between the ages of five and 17. Early on, they believed that mercury-tainted fish and its consumption caused psychological distress and nervous system disorders.

During a press conference on Wednesday, Donna Mergler' the lead author expressed that "You can see this cascade of effects."

“We found that the mother’s childhood mercury exposure is associated with today’s nervous system disorders, as well as a psychological distress.”

“When you eat fish with mercury and you’re pregnant, the mercury is actively transported across the placenta … that affects the [foetus] development,” Mergler noted.

Just before the study published its findings, a teenager committed suicide in the community.

Chrissy Issacs stated that “It’s not their fault. It’s a part of the sickness from the dumping of mercury and I feel like we need to make people aware of that.”

Grassy Narrows has been fighting the provincial and federal administrations for years to cleanse its water system. 

In 2021, the federal government decided to build a $C90 million "mercury care home" to assist persons suffering from mercury poisoning, a project that had previously been delayed.

Rudy Turtle, Grass Narrows First Nation chief sought "fair" compensation for the poisoning's consequences on Wednesday, including counseling and mental health workers.

Turtle also stated that the provincial administration should leave its area after resolving the issues it caused.

“You’ve done enough damage already, why do more?” the chief asked. 

Read next: Canada's Indigenous granted key role in resource projects