Coal news and updates

Grant to reduce, eliminate toxicity of coal mine dust

Increases in lung diseases have been related to respirable coal mine dust. Penn State has been awarded $327,849 from the National Institute for Occupational Safety and Health (NIOSH) to fund research targeting ways to reduce or eliminate the toxicity of respirable coal mine dust.

Recent reports from NIOSH, which has tracked the burden of black lung disease in underground coal miners since 1970, show a steady increase in respiratory disease for miners who have worked for at least 25 years underground. NIOSH estimates 10% of miners are affected, with one in five coal miners from Central Appalachia showing evidence of the disease – the highest level recorded in 25 years.

Barbara Arnold, professor of practice in mining engineering and principal investigator on the project, said the goal of the team’s research is to conduct foundational research to reduce the trend. 

“My dad was a coal miner,” Arnold said. “He never developed any lung-related health issues but black lung is a very debilitating, incurable disease and to see this increase is concerning. Our aim with this project is to see if we can do something to all of those respirable dust particles to essentially turn off the toxicity so it’s safe even if they are inhaled.”

According to Arnold, finding and understanding what to turn off has been a challenge for researchers as respirable coal mine dust is a complex mixture of ultrafine particles. The complexity increases as each particle may have a different chemical composition, size, shape and age. The type of mine can also change the particulate properties. Despite the dynamic variables, previous research hints at a potential culprit for toxicity: hydroxyl radicals, charged molecules that when attached to lung tissue may be the first step towards developing respiratory disease.

“A lot of folks have been doing research focused on coal mine dust, both globally and in the Mining Engineering program at Penn State with its history of the Respirable Dust Center,” Arnold said. “But I looked at it from a mineral processing perspective, not a mining perspective, and I thought we need to really look at the surface chemistry of the materials at play.”

This project will investigate the use of chemical additives to reduce or eliminate dust toxicity.

“One application might be something like flypaper,” Arnold said. “Can the dust be trapped with a nonhazardous chemical that will turn off the toxicity so miners can work safely and turn around this alarming rise in respiratory disease?“

The team will investigate coal mining related respirable dust including ultrafine particles of coal, coal-related quartz, coal-related pyrite and diesel particulate matter, individually and in blends. The goal is to provide insight into the chemicals required for each different material, which could lead to possible additive combinations to be used for different coal components.

“We plan on testing the coal-related pyrite as well, because there is some evidence that the iron in pyrite can cause issues in toxicity,” Arnold said.

In addition, fresh particles and aged particles will be tested to determine if particle surface chemistry changes with aging and oxidation.

Tests will also be conducted with simulated lung fluid to determine if particle toxicity is enhanced in that medium and, therefore, in the lung. During the project, researchers will collaborate with industry representatives regarding applications of any promising chemical additives for future study or implementation.

Arnold hopes the expanded focus on pyrites and crystalline silica from quartz will build the groundwork for wider applications such as metal and non-metal mining, and even to construction where crystalline silica dust is generated when working with brick or concrete.

“Quartz is ubiquitous; it is in everything,” Arnold said. “If we can figure out what we can do with quartz, that gives us a chance at understanding what to do with coal, and we can really improve the lives of so many beyond just miners.”

Mohammad Rezaee, the Centennial Career Development Professor in Mining Engineering and assistant professor of mining engineering, and Sekhar Bhattacharyya, chair of the Mining Engineering program and associate teaching professor, both in the John and Willie Leone Family Department of Energy and Mineral Engineering, are co-principal investigators on the project.