Preliminary results show elevated lead levels in some Yellowknife kids

Some kids and youth in Yellowknife could have elevated levels of lead in their systems — and no one quite knows why. 

Those are the preliminary results from a study started in Yellowknife five years ago, called the Health Effects Monitoring Program. 

The program is a requirement of the environmental assessment for Giant Mine's cleanup plan to determine whether contaminants from the mine affect human bodies. 

Dr. Laurie Chan, a toxicologist and the study's lead researcher, said urine tests aren't a good indicator of the amount of lead in a person's body. 

That's because everyone excretes different levels of lead in their urine. 

"So usually when we believe someone may have high level of lead, we will get blood samples and blood is a very good indicator of how much lead is in your body," he said. 

Chan said the levels were in the top five per cent in the country. 

But it could be a false alarm, he said. 

"But it is good to be, you know, be more careful, right? Because lead affects the IQ development of children, or the brain development. So, it's not good. There's no safe level for lead."

He said in the baseline study five years ago, 10 kids had high levels of lead in their urine. When their blood was tested, "there was no concern" with their lead levels, Chan said. 

Surprised by the results, Chan said the research team looked back at air quality and water quality data for the last five years in Yellowknife. 

But there was nothing to indicate the air, including wildfire smoke, or the water caused the high levels of lead. 

"There's no immediate danger. We don't expect these kids to get sick," he said.

408 children and youth participated in the 2017-18 study, while 142 returned for the 2023 study. Another 120 kids were selected at random for the study last year. 

Chan said they have about 40 kids and youth ages three to 19 who they've invited to come back and have their blood tested. 

Arsenic levels in those tested had not changed much since last time, Chan said. 

The study will continue every five years for the next 20 years.