Hydrogen Sulfide Formation and Potential Health Consequences in Coal Mining Regions

Abstract

Coal is the world’s largest energy source for electricity generation and is mined on 6 continents. Sulfate contamination of surface and ground water from these mining and processing operations is well recognized and commonly monitored as a primary indicator of coal mining impact to surface water and groundwater. However, under conditions frequently found in natural waters, especially groundwater, sulfate can be reduced by naturally occurring sulfate-reducing bacteria, creating hydrogen sulfide. As many communities that are adjacent to these operations rely on groundwater as their primary potable water source, this hydrogen sulfide gas is a largely unrecognized contaminant. Recently, investigators have found connection between coal production and negative health consequences, including increased risk of respiratory diseases (Hendryx and Ahern, in Am. J. Public Health 98(4):669–671, 2008). Hydrogen sulfide is a contaminant associated with the same types of toxic effects as those found at increased prevalence in mining communities. This study of the central Appalachia region of the U.S. finds that when drinking water aquifers are contaminated, sulfide is liberated as a gas during domestic water use, creating conditions in coalfield homes where short-term and long-term exposures can exceed applicable health standards. Our investigation finds that this occurs at a concentration and frequency that warrants recognition by regulatory agencies and is monitored as commonly occurring mining-related contamination and a potential public health hazard.