Coal naturally contains high amounts of mercury. When coal is burned in coal power plants to produce electricity, it creates two sources of mercury exposure:
a. mercury emissions into the atmosphere
b. mercury in coal-combustible by-products (CCBs) such as fly ash
Research has implicated air-borne mercury as a contributing factor to autism. A 2008 Texas study found a significant increase in risk of autism diagnosis related to proximity to coal plants or other industrial mercury emitters (see Proximity to Point Sources of Environmental Mercury Release as a Predictor of Autism Prevalence). A 2006 San Francisco study found an association between autism and the amount of mercury in the air. See the SafeMinds Environmental Autism and Mercury flyer for more details.
“Clean Coal” will never be clean. Existing technologies can reduce airborne mercury emissions up to 90%. However, these technologies will not eliminate mercury air pollution or the concentrated mercury present in Coal-Combustion By-Products (CCBs) produced by coal-fired power plants. Long-term solutions are needed to shift energy production away from coal-fired power plants to cleaner non-mercury polluting technologies, like solar and wind technology. SafeMinds has written a policy statement for a mercury-free energy policy (download HERE). The policy statement includes SafeMinds views on coal, natural gas, and mercury-containing lightbulbs.
There is currently more regulatory focus on reducing mercury emissions. Whereas it is crucial to reduce mercury emissions with the best-available technology, technology does not provide a means to remove 100% of the mercury from emissions. Further, there is a concern that the technology used to reduce mercury emissions may result in an increased amount of mercury in Coal Combusion By-products (CCB’s, a.k.a. CCW “Coal Combustion Waste). And as the recent coal-ash spill in Tennessee demonstrated, CCB’s are a large and lightly-regulated source of exposure to mercury and other toxic chemicals.