Review of the U.S. Department of Energy Office of Fossil Energy's Research Plan for Fine Particulates (1999) / Chapter Skim
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2 Background and Summary
2 Background and Summary
Pages 12-20
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From page 12... ...
the options for emission-control technologies of gases and particles that would reduce ambient PM2 5 loadings. Sulfur dioxide and NOx emissions from coalfired power plants are areas of focus because these precursor gases lead to the formation of secondary particles containing sulfates and nitrates, which are the main contributors to concentrations of fine particles in the ambient air.
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From page 13... ...
. Ultrafine particles as a potential cause of the observed health effects are the focus of several European epidemiologic studies and a component of the Atlanta-Based Aerosol Research Inhalation Epidemiology Study (ARIES)
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From page 14... ...
REGIONAL HAZE AND IMPAIRED VISIBILITY The degradation of the visual environment is the most direct and noticeable effect of fine particles in the atmosphere. The effects include decreased visual range, the discoloration of distant objects, and the whitening of the blue sky caused by the scattering and absorption of sunlight by atmospheric particles.
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From page 15... ...
The higher concentrations of PM2 5 in the eastern United States are attributed to higher emissions of sulfur dioxide in the region and the resulting concentration of ammonium sulfate. Several areas in California, such as the San Joaquin Valley and the Rubidoux area of the South Coast Basin, also have high concentrations of ammonium nitrate.
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From page 16... ...
Consistent measurements of fine particulate mass are made by using the standardized FRM (federal reference method) , which is appropriate for establishing compliance with the ambient air quality standard but is not suitable for determining sources of fine particles or characterizing ambient PM.
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From page 17... ...
The chemical composition of the primary fine particle emissions is the basis for receptor models to determine the contributions of various sources to ambient fine particle mass. Although chemical fingerprints of emissions from generic coal-fired power plants have been identified, the fingerprints have probably been altered as a result of recent and planned reductions in emissions of sulfur dioxide and NOx required by the 1990 Clean Air Act Amendments and the recent SIPs for achieving NOx reductions.
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From page 18... ...
The response of the sulfate concentrations in the eastern United States to changes in sulfur dioxide emissions was investigated during the NAPAP, which concluded that the most significant deviations from linearity occur during the winter close to the source regions (NAPAP, 1991~. For specific episodes, a 50 percent reduction in emissions by all sulfur dioxide sources was predicted to result in reductions of the sulfate concentrations of 35 percent.
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From page 19... ...
As a result, the present database is inadequate for estimating the contributions of primary particles from coal combustion to personal exposures to primary PM. Because most epidemiologic studies must rely on ambient air quality data rather than individual personal measures that constitute actual exposure, these studies are affected by "measurement errors" (the difference between ambient and average personal measures)
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From page 20... ...
. To comply with current PM emission limits, the majority of coal-fired electric utility boilers control primary particulates with electrostatic precipitators, which use electric fields to remove particulates from boiler flue gas.
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