Unintended consequences of air pollution control: Understanding fly ash exposures and cumulative risks

The December 2008 fly ash containment failure in Tennessee was an environmental disaster. Will it be a public health disaster? Coal combustion waste has numerous inorganic constituents, many of which are associated with health effects in studies of animal or human exposures. Exposures to human populations may occur depending on the methods of coal combustion waste disposal. Reclamation of mines and surface impoundments have resulted in some instances of contamination of drinking water sources. Fly ash constituents have been associated with health outcomes such as cancer, neurological, kidney, blood and gastrointestinal effects. A summary of health effects information for coal combustion waste constituents following studies of oral (ingestion) exposures will be provided. Cumulative risk assessment methods will be applied to examine potential health effects from exposure to fly ash. The environmental consequences of relying on coal for energy production manifest in multiple ways, some global such as climate change and some local, such as managing and disposing of coal combustion wastes. Understanding and mitigating the public health impacts will depend on a comprehensive health assessment approach including the methods of cumulative risk assessment.