carbon dioxide production stands in the ratio of 1.0 to 0.8 to 0.6 for coal, oil, and natural gas; for coal-derived liquids it is 1.4.69
The Clean Air Act as amended requires that the Environmental Protection Agency review the ambient air quality standards every 5 years and change them if the criteria indicate such action. The first such review was completed early in 1979.70 Ozone, which had been regarded as a parameter of the photochemical oxidants, was redefined as a pollutant, and its permissible level was raised from 0.08 to 0.12 ppm.71 The agency argued that no significant disadvantage to health or welfare would result from such a change and that the level of smog would be unaffected, As a formal result, it is expected that the 86 percent violation rate recorded in 1977 (and noted above) will be decreased in 1979.
Court actions are being instituted challenging the agency’s position, some arguing that the standard should not have been relaxed, others that it was not relaxed enough. A critical survey of the decision-making process for the new ozone standard would enable standard-setters of the future to learn from this experience. The scientific and sociological factors that led to relaxing the ozone standard should be compared to those that led to greatly increased stringency in the radiation standard discussed previously.
Projections The National Energy Plan (NEP) of 1977 called for the use of 13.5 additional quads of coal by utilities and 4.5 quads by industry in 1990. A joint analysis by six national laboratories72 concluded that, of various factors, the degradation of air quality would be the major constraint in reaching this goal and that its prevention depends critically on siting. The analysis, which concentrated on particulates and sulfur oxides, was based on county-by-county (not within-county) data and assumed that the increase in use would tend to be directly proportional to current use (August 1977). Because such a distribution places increased use in or near many nonattainment or limited areas, approximately 50 percent of the projected industrial use of coal and 25 percent of that projected for utilities was constrained.
These estimates are inflated by the use of county-level analysis that ignores the adjustments possible within counties. Overall, the estimated atmospheric levels of pollutants were about the same on regional and national maps as today’s levels, owing to the emission controls required of new plants.
We judge that these results do not rule out doubling the use of coal. They demonstrate the necessity for integrating the several problems of siting (on both a within-county and a regional basis) with other aspects of energy planning.
As indicated in the following section, the epidemiological evidence concerning the health impact of air pollution from coal combustion