A coal ash impoundment in Rockingham County, North Carolina failed in 2014, releasing coal ash and ash pond water into the Dan River. University of Mississippi researcher Kris Zierold's recent study found that cancer rates are consistently higher in the counties surrounding coal ash impoundments. Photo by Steven Alexander/U.S. Fisheries and Wildlife Services
National analysis finds higher cancer rates in communities near impoundments
Counties near coal ash storage facilities are more likely to report higher cancer rates, raising questions about regulation and long-term health risks of such installations, a new study concludes.
University of Mississippi public health professor and senior author Kristina Zierold worked with researchers from the University of Louisville on a study that found cancer rates are consistently higher in counties and communities that surround coal ash impoundments. They published their findings in Environmental Geochemistry and Health.
“What’s in coal ash includes heavy metals, which we know are carcinogenic and are related to a lot of different cancers,” Zierold said. “If you live next to a coal ash surface impoundment or landfill your whole life, you’re being exposed to this.
“This is important because it is an environmental exposure that we can fix.”
The United States produces between 100 million and 130 million tons of coal ash each year, much of which is stored in more than 750 coal ash impoundments across the country and Puerto Rico.
The states with the highest concentrations of impoundments are Illinois, Indiana, Kentucky, Missouri and Texas, but 43 states and Puerto Rico house at least one. Mississippi has four coal ash impoundments in Choctaw, Harrison, Lamar and Jackson counties.
After analyzing county-level data from across the U.S., the researchers found a consistent pattern.
“People living near coal ash impoundments experience higher cancer incidence rates, a pattern that appears repeatedly across the United States, particularly in the eastern regions where coal‑fired power plants and coal‑ash storage facilities are densely concentrated,” said Charlie Zhang, a professor in the Department of Geographic and Environmental Sciences and first author employed at the University of Louisville.
“Although the study does not establish direct causation between coal ash exposure and cancer in individuals, the consistency and strength of the association raise serious public health concerns. Put simply: wherever coal ash is present, cancer rates tend to be higher – too frequently and too consistently to be dismissed.”
Regulation surrounding coal ash impoundments was minimal in the United States until 2008, when the Kingston TVA Coal Ash Spill released more than 1 billion gallons of coal ash slurry into the surrounding environment. It was the country’s largest industrial spill.
The first comprehensive federal rules governing coal ash were implemented in 2015, and new rules finalized in 2024 expanded oversight to include older legacy impoundments, which were previously exempt.
These regulations included requiring covers that would limit the release of fly ash, which can contain heavy metals such as arsenic, cadmium and lead, and liners that reduce the amount of toxins leaching into groundwater and soil.
The EPA in January extended the deadline for these safety measures to be implemented until 2031. This month, the EPA also proposed rolling back 2024 regulations surrounding coal ash clean-up and storage standards.
Until those safety measures are in place, communities living near coal ash impoundments should take preemptive measures to reduce their contact with coal dust, the researchers said.
“First, we would emphasize this is not about panic, but about informed caution,” Zhang said.
Some of the authors’ recommendations include:
- Test drinking water, especially well water
- Use certified water filters for drinking water
- Seal windows and doors to keep coal dust out of the home
- Refrain from eating outdoors
- Don’t eat food from gardens – including personal gardens – planted near impoundments
- Take shoes off outside
- Wear respirators when mowing the lawn or doing other outdoor yard activities
- Wash hands frequently.
“The big thing is to be aware,” Zierold said. “Be aware of what impoundment – or any major industry – is around you and how that might impact your air quality.”
For policymakers, the researchers advise that clear steps are needed to reduce the risk, including strengthening coal ash regulations, expanded monitoring of drinking water and air, and clear communication with residents who live in affected areas.
“We hope policymakers treat this study as a public health warning, not merely an academic finding,” Zhang said. “In short: act now on prevention and cleanup, even as additional research continues.”
By Clara Turnage
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