UGRC Keynote Speaker

Releasing our toxic legacy: How wetland wildfires are releasing historical industrial pollution to our air, land, and water

Dr. Colin McCarter

Wetlands have long served as repositories for our toxic legacy, retaining centuries’ worth of arsenic, lead, copper, and other toxic metals and metalloids. These swampy vaults trap pollutants within them, cleaning the water and giving wetlands the moniker “the kidneys of the environment”. With increasing resource development, urbanization, and climate change, our wetlands are drying out, making them susceptible to wildfire and returning our toxic legacy to the land, water, and air. Once released, these pollutants can negatively impact human and environmental health. For example, in one of Canada’s largest historical gold mining regions, the 2023 wildfires likely released more stored arsenic than all accidental industrial arsenic releases in Canada. While this risk has remained unacknowledged, wetland fires across the northern hemisphere have been emitting globally significant amounts of lead into our environment every year. However, we can minimize current and future releases of our toxic legacies through careful management and restoration of our degraded wetlands. We will explore how industrial pollution, climate change, and wildfires are opening these swampy vaults, releasing their toxic legacy to our land, air, and water.