As Air Pollution Declined, Tribal Nations Got Left Out
Although air pollution in the U.S. had been on a steady decline over the last two decades (until recently), the benefits have not been evenly distributed. A new analysis of data between 2000 and 2018 shows that trends for Native American communities on tribal land have not kept up with the decline in other communities, which means Native Americans now bear an increasing burden of dangerous air pollutants.
The research, published Wednesday in the American Journal of Public Health, adds to ample past studies that have documented the disproportionately high exposure among people of color in urban areas, especially those in Black and brown neighborhoods that have historically faced racially restrictive redlining policies.
But data has been more limited in sparsely populated areas throughout rural America, including on tribal lands. “Anecdotally we know that tribes reside near industrial facilities, oil and gas operations, but there hasn’t been any comprehensive analysis of air pollution concentrations,” says Maggie Li, a doctoral student at Columbia University’s Mailman School of Public Health.
The study, from Li and her team, attempts to fill the information gap and paint a clearer picture of the burden on tribal communities by combining available monitoring data with satellite prediction models on concentrations of PM2.5 — or fine particulate matter, the smallest, most dangerous kind of air pollutant.
The researchers found that while PM2.5 concentrations started out lower in tribal communities than in non-Native American communities — the difference was 1.46 micrograms per cubic meter in 2000 — the latter saw steeper declines over the next two decades. In fact, by 2015, tribal communities were the ones seeing higher levels, and by 2018, concentrations in tribal areas exceeded other communities by an average of 0.66 micrograms per cubic meter.
“The data show what activists and community leaders have been saying for so long, how their communities are facing environmental justice issues with air pollution," Li says.
The researchers studied PM2.5 concentrations in more than 3,100 counties in the contiguous U.S., 199 of which were defined as American Indian populated counties based on their proportion of the tribal population and federally recognized tribal land.
A separate report from the Clean Air Task Force estimates that indigenous communities are more likely than other populations to live within a half-mile radius of oil and gas facilities, exposing residents to volatile organic compounds and nitrogen oxides. Together they make up the components of ozone smog, which, while more commonly associated with urban areas, exacerbate health disparities that Native Americans on tribal land land already face. American Indians and Alaskan Natives have disproportionately higher rates of asthma, as well as diabetes, heart disease and chronic lung disease. Research has also suggested that globally, long-term exposure to high PM2.5 levels can lower life expectancy by 2.2 years for the average person.
To mitigate the health impacts, tribes have to first monitor the air quality over their land. But many have struggled to launch such programs due to a lack of funding.
The number of tribal air quality programs has declined since 2012, according to a budget analysis by the National Tribal Air Association. The Environmental Protection Agency grants tribes roughly $11.8 million in funding each year for air quality programs under the Clean Air Act. That figure became to $12.4 million for the first time in five years in 2021, but the amount remains insufficient as the number of federally recognized tribes increases, according to the analysis.
The analysis recommends that the budget increase to at least $18.3 million to account for inflation and the growing number of tribal beneficiaries, and as much as $31.8 million to take increased health care costs into consideration.