Primary ambient air quality

Annual United States National Primary Ambient Air Quality Standard promulgated in 1971 ... 

Notes National primary ambient air quality standards define levels of air quality which the EPA Administrator judges are necessary, with an adequate margin of safety, to protect the public health. National secondary ambient air quality standards define levels of air quality, which the Administrator judges necessary to protect the public welfare from any known or anticipated adverse effects of a pollutant. 

The federal primary ambient air quality standard for photochemical... 

Note that the definition of a U.S. primary ambient air quality standard is one designed to protect the... 

Maximum allowable increase over baseline air quality, lg/m Primary ambient air-quality standard, R m ... 

The legislation also required the Environmental Protection Agency (EPA) to establish national primary ambient air quality standards to protect health and secondary standards to protect the public welfare. Ambient standards were greatly needed as a guide to the degree of emission controls required in various regions. National standards for particulates, sulfur oxides, nitrogen oxides, carbon monoxide and hydro-... 

The Clean Air Act of 1967, amended in 1970, called upon the Administrator of the Environmental Protection Agency (EPA) to promulgate national primary and secondary ambient air quality standards for each air pollutant for which air quality criteria have been issued (2). A national primary ambient air quality standard is the maximum ground level pollutant concentration which in the judgment of the Administrator of EPA can be tolerated to protect the public health, based on the published air quality criteria. A national secondary ambient air quality standard is a more stringent concentration level which in the. judgment of the Administrator is required to protect the public welfare from any known or anticipated adverse effect associated with the presence of the air pollutant in the ambient air. The criteria for an air pollutant, to the extent that is practical, shall include those variable factors which may alter the effects on public health or welfare by the air pollutant and any known or anticipated adverse effects on welfare. 

Figure 2 summarizes the basic difference between the 1975 national stationary source demand for low sulfur coal and oil, based on State Implementation Plan (SIP) estimates of that necessary to achieve primary ambient air quality standards and the projected 1975 supply of these fuels (6, 7, 8, 9, 10, 11). The net result is a forecast coal/oil supply deficit on the basis of sulfur content and including foreign imports, of approximately 8 XlO Btu. This is equivalent to a combined annual shortage of about 230 million tons of coal and 300 million barrels of primarily residual oil. Table II shows the regional distribution of these shortages. In the judgment of the author, uncertainties in factors such as sulfur content analyses, production potentials, and the commercial impact of environmental standards by 1975 limit the accuracy of these supply deficit forecasts to about 20%. 

The second example is the Niagara Frontier AQCR (Buffalo, N.Y.). The highest annual average ambient SOj. concentration recorded at any receptor in this AQCR is 197 /xg/m. The ambient SOa concentration at this receptor could be reduced below the primary ambient air quality standard of 80 /xg/m by the control of one source only to a level of at least 95%. The importance of this single industrial combustion source can further be shown by the fact that, if all other sources impacting on this worst receptor had 100% control, this single combustion source would... 

TABLE 25-1 National Primary and Secondary Ambient Air Quality Standards... 

NR = No index values reported at concentration levels below those specified by "alert level" criteria (Table 5-1). Annual primary National Ambient Air Quality Standard. 

There are several different strategies for air pollution control. The strategy just discussed and shown in Fig. 5-1 is called the air quality management strategy. It is distinguished from other strategies by its primary reliance on the development and promulgation of ambient air quality standards. 

United States National Primary and Secondary Ambient Air Quality Standard, attained when the expected number of days per calendar year with maximum hourly average concentrations above 0.12 ppm is equal to or less than 1, as determined in a specified manner... 

The EPA sets two kinds of national ambient air quality standards. The primary standard is set at a level intended to protect human health with an adequate margin of safety. The secondary standard, usually less stringent, is set based on protecting the public welfare, which can include factors other than health impacts, such as reduced visibility, atid damage to crops. 

U.S. Environmental Protection Agency. Part 410—National primary and secondary ambient air quality standards. Federal Roister 36 8186-8201, 1971. 

Under the terms of the Clean Air Act of 1970, as amended in 1990, the Environmental Protection Agency is required to establish National Ambient Air Quality Standards (NAAQS) for pollutants considered to be hazardous to public health and the environment. These standards are of two types primary and secondary. Primary standards apply to "sensitive" members of the population, including the elderly, young children, and people who have respiratory disorders. Secondary standards apply to the general public and include risks to other parts of the environment, including visibility, animals, crops, vegetation, and buildings. 

EPA Primary and secondary ambient air quality standards 0.053 ppm, annual arithmetic mean concentration EPA 1993... 

National primary and secondary ambient air quality standards... 

This model has been exercised on a variety of AQCR s for which an accurate emission inventory, meteorological data base, and measured ground level pollutant concentrations are available. The results discussed in this paper represent analyses of the New York, Philadelphia, Niagara Frontier, St. Louis, and Milwaukee AQCRs 13, 14). These AQCRs represent a reasonable cross-section of the eastern urban AQCRs where the primary sulfur dioxide ambient air quality problem exists. The results of these analyses indicate that the level of control required by emission source to achieve ambient air quality standards can be forecast with greatly increased assurance. The following conclusions from this exercise should be considered in the near-term achievement of ambient air quality standards. 

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