New research shows that wildfires – especially intense ones – can raise concentrations of mercury in waterways.
Investigators tested headwaters in 36 burned sites and 21 unburned sites in Idaho, Washington and Oregon. What they found was burned watersheds had an 89% higher concentration of mercury in suspended particles. The likely culprit is erosion, which carries mercury into the water.
They also found that concentrations of its more toxic form, methylmercury, were 178% higher.
Methylmercury can cause vision changes, sensory disturbances in extremities, muscle wasting and other ailments, according to the CDC.
Lead author Austin Baldwin, an Idaho-based researcher with the U.S. Geological Survey, said their study suggests a relationship between burn severity and methylmercury concentrations.
“With increasing wildfire severity and frequency, our data suggests that we could probably expect to see greater methylmercury transport and bioaccumulation in at least some species,” he said.
Baldwin suggested that prescribed fires could be one response to address this risk, as they are a proven method to reduce the intensity of blazes.
“If you can reduce burn severity, you can potentially reduce methylmercury transport,” he said.
While the study sites were in the Northwest, he said it’s likely similar results would be seen elsewhere in the West.
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Nevada Public Radio, Boise State Public Radio in Idaho, KUNR in Nevada, KUNC in Colorado and KANW in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.
