POTENTIAL HEALTH RISK REDUCTION ARISING FROM REDUCED MERCURY EMISSIONS FROM COAL FIRED POWER PLANTS.

Download or read book POTENTIAL HEALTH RISK REDUCTION ARISING FROM REDUCED MERCURY EMISSIONS FROM COAL FIRED POWER PLANTS. written by and published by . This book was released on 2001 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: The U.S. Environmental Protection Agency (EPA) has announced plans to regulate mercury (Hg) emissions from coal-fired power plants. EPA has not prepared a quantitative assessment of the reduction in risk that could be achieved through reduction in coal plant emissions of Hg. To address this issue, Brookhaven National Laboratory (BNL) with support from the U.S. Department of Energy Office of Fossil Energy (DOE FE) prepared a quantitative assessment of the reduction in human health risk that could be achieved through reduction in coal plant emissions of Hg. The primary pathway for Hg exposure is through consumption of fish. The most susceptible population to Hg exposure is the fetus. Therefore the risk assessment focused on consumption of fish by women of child-bearing age. Dose response factors were generated from studies on loss of cognitive abilities (language skills, motor skills, etc.) by young children whose mothers consumed large amounts of fish with high Hg levels. Population risks were estimated for the general population in three regions of the country, (the Midwest, Northeast, and Southeast) that were identified by EPA as being heavily impacted by coal emissions. Three scenarios for reducing Hg emissions from coal plants were considered: (1) A base case using current conditions; (2) A 50% reduction; and, (3) A 90% reduction. These reductions in emissions were assumed to translate linearly into a reduction in fish Hg levels of 8.6% and 15.5%, respectively. Population risk estimates were also calculated for two subsistence fisher populations. These groups of people consume substantially more fish than the general public and, depending on location, the fish may contain higher Hg levels than average. Risk estimates for these groups were calculated for the three Hg levels used for the general population analyses. Analysis shows that the general population risks for exposure of the fetus to Hg are small. Estimated risks under current conditions (i.e., no specific Hg controls) ranged from 5.7 x 10−6 in the Midwest to 2 x 10−5 in the Southeast. Reducing emissions from coal plants by 90% reduced the estimated range in risk to 5 x 10−6 in the Midwest and 1.5 x 10−5 in Southeast, respectively. The population risk for the subsistence fisher using the Southeast regional fish Hg levels was 3.8 x 10−3, a factor of 200 greater than the general population risk. For the subsistence fishers and the Savannah River Hg levels, the population risk was 4.3 x 10−5, a factor of 2 greater than for the general population. The estimated risk reductions from a 90% reduction in coal plant Hg emissions ranged from 25%-68%, which is greater than the assumed reduction in Hg levels in fish, (15.5%). To place this risk in perspective, there are approximately 4 x 106 births/year in the U.S (National Vital Statistics Report, 2000). Assuming that the Southeast risk level (the highest of the regions) is appropriate for the entire U.S., an estimate of 80 newborn children per year have a 5% chance of realizing any of the 16 adverse effects used to generate the DRF. If Hg emissions from power plants are reduced 90%, the number of children at risk is reduced to 60.