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7 Emissions, Air Quality, and Human Health
Pages 209-248

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From page 209...
... , we briefly summarized the steps needed to estimate environmental and public-health effects, including a general discussion of the important components of atmospheric fate and transport models. In addition, the committee provided an overview of the health effects of the air pollutants potentially influenced by NSR, the attainment-nonattainment status of different geographic areas, and trends in emissions across time and economic sectors.
From page 210...
... that are regulated under the National Ambient Air Quality Standards (NAAQS) (Table 2-1)
From page 211...
... EMISSIONS, AIR QUALITY, AND HUMAN HEALTH 211 which is termed primary aerosol. NSR changes that affect VOC, NOx, SO2, and primary PM emissions will affect O3 and PM2.5 NAAQS attainment.
From page 212...
... Emissions are stratified by sector and state to provide further context about the sectors and locations that may contribute most substantially to ambient air pollution and related health effects. Data from our interim report about national regional emissions patterns and temporal trends in emissions are also included.
From page 213...
... Fraction of Total Emissions Potentially Subject to New Source Review The fraction of emissions potentially subject to NSR was estimated from the NEI for each state by summing 1999 point source SO2, NOx, PM2.5, and VOC emissions from individual emitters with greater than and less than 100 tons/year. Emissions exceeding 100 tons/year were assumed to be subject to NSR, although several of the included sources may be subject to a 250 tons/year limit.
From page 214...
... 214 USA over oming y W Virginia Wisconsin emissions est ashington W Virginia W mont r e Utah V xas e T point-source ota ennessee Dak T all Carolina South Island that ania South Rhode Oregon ennsylv P Assumes COV ota Ohio Oklahoma Dak th NSR. k r o Y Carolina Nor to w th y xico Ne Nor Me Jerse w PM2.5 w Ne subject Ne ada v Hampshire Ne w Ne 7-1 i Nebraska NOx Montana State potentially Missour are Mississippi shown.
From page 215...
... EMISSIONS, AIR QUALITY, AND HUMAN HEALTH 21 eligible sources. Only in Alaska, California, the District of Columbia, Idaho, Iowa, Kansas, Massachusetts, Minnesota, Nebraska, Nevada, Oklahoma, Oregon, Rhode Island, South Dakota, and Vermont is less than 5% of total emissions derived from point sources that have PM2.5 emissions over 100 tons/year.
From page 218...
... 218 NEW SOURCE REVIEW FOR STATIONARY SOURCES OF AIR POLLUTION industry, with the remaining contributions due to fuel combustion at other industrial sources (Figure 7-2)
From page 220...
... 220 Continued 7-3 (b)
From page 221...
... 221 Continued 7-3 (c)
From page 222...
... 222 Continued 7-3 (d)
From page 223...
... . Although information on facility age is not available for all sectors, relevant data inferred from boiler sales are available for the electric utility sector and for commercial and industrial boilers (EEA, 2005)
From page 224...
... 224 NEW SOURCE REVIEW FOR STATIONARY SOURCES OF AIR POLLUTION TABLE 7-1 Emissions from Coal-Fired Electricity Generation by Age (a) 2002 NOx Emissions and Share of Generation of Coal-Fired Capacity by Vintage % of NOx % of Avg.
From page 225...
... EMISSIONS, AIR QUALITY, AND HUMAN HEALTH 22 TABLE 7-1 Continued (d) 2002 SO2 Emissions and Performance of Coal-Fired Capacity by NSPSc % of SO2 Average SO2 % of Emitted Average Average NSPS Status Emission % of Coal-Fired per % of Capacity Heat Rate According to Rate Total SO2 Electricity Electricity Factorb (Btu/kWh EIA 767 (lb/MWh)
From page 226...
... 226 NEW SOURCE REVIEW FOR STATIONARY SOURCES OF AIR POLLUTION earlier standards, but NOx emission rates are nearly identical with those of the earlier group. That reflects the fact that NSPS for NOx did not change much in 1978 (Burtraw and Evans 2004)
From page 228...
... 228 NEW SOURCE REVIEW FOR STATIONARY SOURCES OF AIR POLLUTION FIGURE 7-5 Criteria-pollutant emission trends for point sources. SOURCE: Data from EPA 2004i.
From page 229...
... EMISSIONS, AIR QUALITY, AND HUMAN HEALTH 22 Volatile Compounds Organic Particles Organic Semivolatile Compounds Compounds OH Secondary Organic Semivolatile and RO2 Particles Gaseous Compounds O3 O3 OH NO3 Inorganic N2O2 NO NO2 Nitrates O3 HNO3 h Ozone NH4NO3 NH3 OH H2O (NH4) 2SO4 SO2 H2SO4 Chemical Deposition O3, H2O2, O2 FIGURE 7-6 Chemical links between O3 and PM formation.
From page 230...
... model for its updated analyses of the Clean Air Interstate Rule (CAIR)
From page 231...
... EMISSIONS, AIR QUALITY, AND HUMAN HEALTH 231 Geographic location can have three major influences. First, meteorological conditions -- such as temperature, humidity, wind speed and direction -- can influence the fate and transport of a pollutant, including the rate at which SO4, NO3, SOA, and O3 are formed and their dispersion.
From page 232...
... 232 NEW SOURCE REVIEW FOR STATIONARY SOURCES OF AIR POLLUTION the plains states of the Midwest, concentrations of NH3 are high and SO4 concentrations lower, so NOx reductions might result in reductions in PM2.5 ammonium nitrate concentrations. PM2.5 travels hundreds or thousands of kilometers, so the plume from a given source may travel through multiple regimes.
From page 233...
... . Composition of PM2.5 Although the combination of emission inventory data and attainmentnonattainment status provides some insight into geographic patterns, it does not directly address the relative source contributions in a specific geographic area.
From page 236...
... 236 NEW SOURCE REVIEW FOR STATIONARY SOURCES OF AIR POLLUTION HEALTH EFFECTS The final step in understanding the health effects of changes in emissions would involve quantifying the effects of the modeled ambient concentration changes on a variety of health outcomes. Nonattainment areas indicate where the air is deemed unhealthful according to the current NAAQS (Table 2-1)
From page 237...
... EMISSIONS, AIR QUALITY, AND HUMAN HEALTH 23 underlying cardiovascular diseases and diabetes)
From page 238...
... NO and NO2 have numerous sources, especially combustion emissions, and are present in ambient air in greater concentrations than the other species. NO2 is toxic by virtue of its oxidation potential and has received the greatest health-research and risk-assessment attention.
From page 239...
... EMISSIONS, AIR QUALITY, AND HUMAN HEALTH 23 lower pollution were statistically associated with NO2 and with airborne acid and PM2.5, substances to which NOx contributes. NO2 (and other air pollutants)
From page 240...
... . Suspended Particulate Matter PM encompasses a physically and chemically diverse class of ambient air pollutants of both anthropogenic and biologic origin.
From page 241...
... The quantitative relationship between PM exposure and health effects remains uncertain, as does the proportion of the criteria-pollutant health effects attributable to PM copollutants. Despite the uncertainties and the attendant debates, it seems clear that current concentrations in some areas and at some times in the United States are associated with health burdens that warrant concern, and a causal interpretation of the epidemiologic evidence implies a public-health burden from PM exceeding that from other criteria air pollutants (EPA 2004h)
From page 242...
... However, until we have a better understanding of the specific physical-chemical air-pollutant species causing cardiopulmonary morbidity and mortality, we cannot ignore the possible direct contribution of SO2. Volatile Organic Compounds In addition to the criteria pollutants, emissions addressed by the NSR program include a diverse group of VOCs.
From page 243...
... . The Clean Air Act lists 188 HAP species or classes.
From page 244...
... 244 NEW SOURCE REVIEW FOR STATIONARY SOURCES OF AIR POLLUTION TABLE 7-2 Urban Air Toxics Acetaldehydea Coke-oven emissions Mercury compounds Acroleina 1,3-Dichloropropenea Methylene chloridea Acrylonitrilea Dioxin Nickel compounds Arsenic compounds Ethylene dibromidea Perchloroethylenea Benzenea Ethylene dichloridea Polychlorinated biphenyls (PCBs) Beryllium compounds Ethylene oxidea Polycyclic organic matter 1,3-Butadienea Formaldehydea Propylene dichloridea Cadmium compounds Hexachlorobenzenea Quinolinea Carbon tetrachloridea Hydrazinea 1,1,2,2-tetrachloroethanea Chloroforma Lead compounds Trichloroethylenea Chromium compounds Manganese compounds Vinyl chloridea aAlso a volatile organic compound (VOC)
From page 245...
... EMISSIONS, AIR QUALITY, AND HUMAN HEALTH 24 studies lacking accurate personal-exposure data have a limited ability to detect thresholds if they exist. Furthermore, although animal studies have provided insight into mechanisms of response and confirmed the toxicity of some PM components, few statistically significant responses have been demonstrated in the laboratory at ambient exposure concentrations.
From page 246...
... 246 NEW SOURCE REVIEW FOR STATIONARY SOURCES OF AIR POLLUTION Influence of Geographic Location of Sources on Potential Health Effects Our final question is related to the population health effects associated with emission changes. A relevant calculation would integrate atmospheric fate and transport with population patterns and ambient concentrations downwind of sources.
From page 247...
... · On the basis of emissions data, attainment-nonattainment status, and health evidence, O3 and PM2.5 are the criteria air pollutants most likely to contribute to health effects of NSR rule changes, although uncertainties remain regarding the extent to which these pollutants represent indexes rather than direct causative agents. · Atmospheric fate and transport models constitute the recommended approach to determine the O3 and PM2.5 concentration changes associated with NSR rule changes, but model users should ensure that such models incorporate critical phenomena of O3 and secondary aerosol chemistry over long downwind distances.
From page 248...
... 248 NEW SOURCE REVIEW FOR STATIONARY SOURCES OF AIR POLLUTION · On the basis of factors influencing O3 and secondary aerosol chemistry, there will be well-defined geographic patterns in the concentration effects of emission changes in O3 and secondary PM precursors, including regional patterns for PM2.5 based on ambient SO4, NO3, and NH3 concentrations and urban-rural patterns for O3 based on ambient concentrations of NOx and VOCs. · The emissions from regions most affected by NSR vary by pollutant.


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