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Researchers collecting more toenails, urine and saliva for Giant Mine study

Hundreds of seacans containing highly contaminated material at Giant Mine. Ollie Williams/Cabin Radio

Researchers looking into the long-term impacts of Giant Mine’s toxic legacy and remediation efforts are collecting biological samples from children and youth.

The Yellowknife Health Effects Monitoring Program was launched in 2017 to meet the requirements of an environmental assessment of the Giant Mine Remediation Project. It aims to monitor baseline levels of arsenic and other metals, including cadmium and lead, in residents of Yellowknife, Ndılǫ, and Dettah, and ensure they do not increase as the Giant Mine site is remediated.

Researchers initially collected samples of urine, saliva and toenail clippings from 2,037 people – 1,531 adults and 506 children and youth – in 2017 and 2018. Participants were also asked to complete a lifestyle and food frequency questionnaire and researchers asked permission to access their medical records from the past five years.

Initial results released in 2019 indicated contaminant levels among Yellowknife-area residents were generally comparable to other Canadians.

Earlier this year, the research team presented further findings suggesting arsenic exposure was not directly linked to diseases such as skin cancer reported among Yellowknife-area residents. They also found concentrations of arsenic in toenail samples were higher among children and samples collected in the spring and summer.



Now, five years into the project, researchers are going door-to-door to 1,000 randomly selected households in Yellowknife asking children and youth aged three to 19 to participate in the study. A news release states they will be asked to provide biological samples and participate in a 30 to 40 minute interview.

Project manager Renata Rosol said participants aged 13 and older can sign a consent form to be interviewed without a parent or guardian present. Younger participants will require the consent of a parent or guardian and in some cases only guardians may be interviewed as long as the child agrees to participate in the study.

People will receive $50 in gift cards for agreeing to participate in the study. They will get a letter with their personal results next year.

Rosol said now that baseline levels of contamination have been established, the aim is to retest children and youth every five years, as well as test new children and youth, as they are still growing and may be vulnerable to contaminant exposure. Researchers plan to retest adults every 10 years.



So far this year, researchers said 225 people have participated in the five-year follow up, 79 of whom are new to the study and 146 who participated in the 2017-18 study. They said they aim to collect samples from a total of 400 people.

Giant Mine operated between 1938 and 2004, during which time it produced more than seven million ounces of gold. Between 1949 and 1951, the mine emitted an estimated 7,500 kilograms of airborne arsenic every day before pollution control was installed. Emissions were then reduced to 5,500 kilograms per day and underground storage of highly toxic arsenic trioxide, a byproduct of the gold roasting process, began.

Cleanup of the former gold mine, which officially began in 2021, is expected to cost more than $4 billion and take until 2038 to complete. Some aspects of the project, including managing the 237,000 tonnes of arsenic trioxide dust stored underground at the site, will require perpetual care and maintenance.

Correction: October 18, 2023 – 15:24 MT. A previous version of this article stated that of the 225 people who have participated in the five-year follow up, 29 were new to the study.