Researchers have known for decades that infants in Northern Canada are disproportionately affected by contaminated breast milk, and now a historian is hoping to learn how that shaped mothers' decisions around breastfeeding.

Liza Piper, an environmental historian from the University of Alberta, will be travelling to Inuvik, Aklavik and Tsiigehtchic, N.W.T., later this month.

She says she'll be speaking with mothers, caregivers and nurses — "anyone who was involved in the decisions about what to feed babies, beginning in the 1970s up to the present" — about how research into polychlorinated biphenyl (PCB) contamination affected decisions to breastfeed.​

"With feeding babies there's a lot of different factors, social, cultural, economic, environmental, that are influencing choices about feeding infants," said Piper.

"What I'm interested to know is what factors did influence these choices... and whether or not the concern about food hazards was part of that."

PCBs are a type of environmental pollutant that enters the food chain through animals and fish and is transferred to humans who consume the contaminated meat. The toxins can pass to infants through a mother's breast milk, delaying brain development and increasing the child's risk of cancer, among other things.

The negative impact of PCBs on human health was known as far back as the 1930s. It wasn't until the 1980s, however, that researchers began to notice that mothers in Northern Canada had unusually elevated levels of the toxin in their breast milk.

"The discovery that women in the North had these elevated levels of PCBs was actually really unintended," explained Piper.

"It was women in Northern Quebec and they were supposed to be a control group for a study that was focused on women in Southern Quebec… In the course of the research they discovered that it was the women in the North who actually had these elevated levels of PCBs."

Since then, there have been public health advisories and educational campaigns about contaminated foods, along with several "studies of environmental contaminants in the N.W.T.," said Piper, including the toxic impacts of local military and industrial activity.

Although she added that, "to my knowledge, the breast milk of women in the N.W.T. has not been specifically tested."

And while there has been a general decline in PCB exposure across the country since the 1980s, the issue is very much still alive, particularly due to the effects of climate change, Piper said.

"I know there's a lot of community driven efforts to learn more about contaminants, some of which shows that there's no need to be concerned or less need to be concerned, some of which has shown that there are in fact problems.

"From what I understand, climate change is actually mobilizing more contaminants in the local environment in particular parts of the North. This has been a concern along the Mackenzie River."