Indigenous communities in California are exposed to disproportionate levels of particulate matter in amounts much greater than previously thought, a new study has found.

Using a new technique of measuring prolonged exposure to wildfire smoke, the researchers discovered that the Indigenous communities were exposed to an average of roughly 1.7 times the smoke that would be expected, considering Indigenous populations statewide each year between 2006 and 2020, reported Berkeley News.

The scientists said their new exposure measurement matrix will assist with understanding the effects of long-term smoke exposure for epidemiological and environmental justice studies — essential for vulnerable communities.

“Analyses spanning 2006 to 2020 revealed that Native American and Alaska Native, multiracial, and non-Hispanic white populations had consistently disproportionate outdoor wildfire PM2.5 [fine particulate matter] exposure. Housing, occupational, behavioral, or economic constraints may result in larger actual disparities,” the researchers wrote in the study paper. “Improved long-term wildfire PM2.5 exposure measurement can support health-equity-focused interventions and climate resilience.”

Co-author of the paper Rachel Morello-Frosch, a UC Berkeley professor of public health and environmental science, policy and management, said the knowledge is becoming more and more important as millions across the United States are being exposed to toxic smoke from ever-increasing climate change-fueled wildfires.

“Now that wildfires are coming at us sequentially, and clearly are going to be increasing in frequency and intensity, we can’t look at them one at a time,” Morello-Frosch said, according to Berkeley News. “We have to look at them using a more cumulative exposure framework.”

Read the full article about wildfire smoke and Indigenous communities by Cristen Hemingway Jaynes at EcoWatch.