Air quality has declined in metropolitan areas across Mississippi, with some counties ranking among the nation’s worst for various pollutants, new research from the American Lung Association shows.
ALA’s 2026 “State of the Air” report assessed air quality in counties across the U.S., assigning letter grades and rankings based on federal pollution metrics from 2022 to 2024. The data predates a boom in data center development across Mississippi, which has sparked concerns about pollution in neighboring communities.
The analysis focused on ozone and particle pollution, two airborne contaminants shown to contribute to serious respiratory and heart diseases. Overall, researchers found that 33.5 million children nationwide are exposed to unsafe levels of air pollution, including more than 65,000 in Mississippi.
“Air quality, not just in Mississippi, but across the nation, is beginning to worsen,” said Calandra Davis, director of advocacy for the ALA in Mississippi. “It feels like we’re taking a step back.”
ALA’s report groups counties into larger metropolitan areas to better understand air quality trends across regions. Based on these groupings, the Jackson-Vicksburg-Brookhaven metro area ranked 143rd out of 226 for ozone prevalence and 154th out of 224 for short-term particle pollution—both slight downgrades from ALA’s 2025 report.
Meanwhile, individual counties like Bolivar and DeSoto fared significantly worse in the ALA’s latest rankings, earning “C” and “F” grades for ozone pollution, respectively. DeSoto’s “F” rating marked the second straight year that the county received a failing grade.
ALA hopes the new report will motivate government agencies to preserve air quality regulations and strengthen pollution protections for vulnerable communities. Under the second Trump administration, the Environmental Protection Agency has rescinded Clean Air Act provisions and loosened guardrails around industrial emissions—an effort that Davis warned will have lasting health consequences for Mississippians.
This deregulatory push includes removing health considerations from the agency’s economic analyses and easing emissions standards for toxic chemicals.
“The EPA has threatened the progress (we’ve made) to clean up air … across the U.S.,” Davis said Tuesday. “Unfortunately, that means that next year’s report may reveal that the air quality, once again, has worsened.”
Davis called for increased regulatory action in places like DeSoto County, where xAI’s growing data center footprint has amplified concerns around air pollution. Data centers are spreading elsewhere in the state, too, like the expansion of the Amazon campuses recently announced in Madison County.
Last week, the NAACP sued xAI over the use of unpermitted gas turbines for xAI data centers at a Southaven energy plant, accusing it of violating federal law and further degrading local air quality. The turbines emit large amounts of nitrogen oxides, a group of highly reactive gases that are precursors to ozone and particle pollution.
Davis urged the Mississippi Department of Environmental Quality to fully consider the impacts of data centers and their corresponding power sources before issuing permits to operators. Last month, state regulators approved a controversial permit allowing xAI to install 41 permanent gas turbines in DeSoto County. Legal organizations have since filed an appeal on behalf of residents.
“We’re simply asking for MDEQ to reject any permit requests that do not assess climate and health impacts first,” Davis explained, adding that the agency should ramp up its air pollution monitoring statewide to better identify areas of concern.
In a statement to the Mississippi Free Press, MDEQ emphasized its commitment to evaluating industrial permit applications in accordance with “applicable state and federal regulations designed to protect human health and the environment.” The agency added that the ALA’s methods for evaluating air quality differ from the regulatory approach set by the EPA.
“MDEQ does not issue permits unless they are compliant with those regulations and cannot ‘reject’ a permit application without a legal basis for doing so,” spokesperson Jan Schaefer wrote in an email Wednesday. “Mississippi’s air quality, as measured under EPA standards, is protective of public health.”
While most Mississippi counties earned passing grades in ALA’s latest report, Davis stressed that addressing hot spots like DeSoto County could benefit other areas with cleaner air.
“Air travels, which means pollution travels,” she concluded. “So protecting the residents of DeSoto County means that we’re also protecting all Mississippians.”
