Understand contaminants in traditional foods and wildlife

Overview

Traditional foods and wildlife are an important part of life in the Northwest Territories. They support physical health, culture, identity, and time on the land. Some environmental contaminants can travel long distances and enter the northern environment. This page explains how contaminants move through the land, water, and food web, and helps you make informed choices when harvesting or eating traditional foods.

Learn how contaminants reach traditional foods

Environmental contaminants in the NWT include heavy metals, persistent organic pollutants (POPs), and radionuclides. Some come from local sources such as mining, but most arrive from other parts of the world through long-range atmospheric transport. Once in the environment, contaminants may: 

  • travel in the air 

  • fall with rain or snow 

  • settle on land or water 

  • be taken up by plants 

  • move into lakes, rivers, and oceans through runoff 
    These substances can enter the food chain when plants and animals absorb them. 

See what affects contaminant levels in animals

Contaminant levels vary between species and individual animals. Two factors influence how much builds up in wildlife: 

Bioaccumulation 

Some contaminants build up in an animal’s body over time. Older animals often have higher levels than younger animals. 

Biomagnification 

Contaminants can increase as they move up the food chain. For example: 

  • lichen absorbs contaminants 

  • caribou eat lichen 

  • wolves eat caribou 

  • Predatory animals often have higher levels, while plant-eating animals tend to have lower levels. Marine mammals can have higher levels because they are often top predators. 

See how contaminants are monitored across the NWT

Many studies measure contaminants in: 

  • wildlife such as caribou, moose, ducks, and fish 

  • air 

  • water 

  • soils and sediments 

Monitoring helps identify trends over time and in different locations. Human biomonitoring studies, which measure contaminants in blood, urine, or hair, help show real exposure levels in communities.

Multiple partners contribute, including the GNWT, the Government of Canada, and independent researchers. 

Find contaminant patterns by species

Use these expandable sections to see general contaminant patterns for commonly harvested animals. These patterns reflect what monitoring has found across species in the NWT. They do not replace fish consumption guidance or lake-specific notices.

Large land animals

Caribou, moose, muskox, beaver, hare, muskrat

  • Levels vary based on age and diet. 
  • Plant-eating animals generally have lower contaminant levels. 
  • Older animals may have higher levels because contaminants can build up over time.  

Moose organ monitoring shows that liver and kidney can have different cadmium levels depending on where the animal was harvested. You can follow region-specific serving advice to keep cadmium intake low while still enjoying moose as a healthy traditional food. Learn how to eat moose liver and kidneys safely [hyperlink to page]. 

Birds and small game

Ducks, geese, ptarmigan, grouse 

  • Levels depend on migration routes, feeding habits, and environmental conditions. 
  • These species are usually lower in the food chain.
Fish and freshwater species

Lake trout, northern pike, walleye, whitefish, Arctic char, grayling, inconnu, cisco, suckers, burbot 

  • Predatory fish may have higher contaminant levels due to biomagnification. 
  • Non predatory fish usually have lower levels. 
  • See “General Guidelines” and lake-specific notices for serving limits.

Use guidance to stay safe while eating traditional foods

Traditional foods remain some of the healthiest options available. The presence of contaminants does not automatically mean harm. Health effects depend on: 

  • dose 

  • duration 

  • route of exposure 

  • individual characteristics 

  • other substances a person may be exposed to 

Avoiding traditional foods can increase the risk of chronic diseases such as diabetes and cardiovascular disease. Following GNWT guidance helps support safe, healthy choices.

If you still need help

Updated: Aug 27, 2026