A number of previous studies have shown poor communities and people of color are exposed to higher levels of harmful pollution. A new report suggests the trend holds true for coal ash.

The report is a joint effort by advocacy groups Earthjustice and Physicians for Social Responsibility. Its authors argue poor and minority communities disproportionately shoulder the social, health and environmental costs of coal ash storage. And when disaster strikes, the same communities are hit the hardest.

Coal ash is the byproduct of coal fire plants. The ash is stored in both dry landfills and wet containment ponds. These facilities are designed to keep the dangerous toxins found in coal ash -- lead, mercury, chromium, cadmium and others -- from leaching into the environment. But as history has shown, they aren't foolproof.

Despite a number of disastrous coal ash spills, researchers at Earthjustice say the American public still isn't aware of just how much coal ash waste is generated each year, and regulators aren't doing enough to ensure the waste is properly managed. Furthermore, they say the toxic sludge disproportionately affects America's most vulnerable citizens.

The report shines the spotlight on the Arrowhead Landfill in Uniontown, a mostly black community in central Alabama. When in 2008, more than one billion gallons of coal ash spilled from a containment pond in Kingston, Tenn., much of the escaped waste was relocated to Uniontown.

"People in Uniontown have all kinds of health problems that they didn't have before," Esther Calhoun, a Uniontown resident, told Environmental Health News. "I am only 51 years old and I have neuropathy."

Calhoun, who serves as president of Black Belt Citizens for Health and Justice, plans to share the story of Uniontown with the U.S. Commission on Civil Rights, which will host a hearing next week on environmental justice and the EPA.

"No one thought that the members of this poor community would fight back or that anyone would listen to us," Calhoun added.

According to the EPA, Calhoun is one of 1.5 million people of color living in the catchment areas of some 277 coal ash storage facilities. Coal ash has been blamed for air and water contamination at 200 or more sites nationwide.

Medical research has linked coal ash and the toxins found within to a range of health problems, including cancer, heart damage, lung disease, respiratory problems, kidney disease.

"In short, coal ash toxics have the potential to injure all of the major organ systems, damage physical health and development, and even contribute to mortality," researchers write in the report.

Environmental activists have increasingly voiced concerns over the risks of coal ash and lack of regulatory oversight. Calhoun says the EPA can begin to solve the problem by better protecting communities of color.

"EPA has to reform the way it runs its Office of Civil Rights so that it actually works to protect communities like ours," she said. "From my perspective, there's really no civil rights enforcement protecting our community from bearing the burden of environmental pollution."