Quality ambient air

COLORANTS FORFOOD,DRUGS,COSTffiTICS AND TffiDICALDEVICES] (Vol 6) NAAQS. See National Ambient Air Quality Standard. 

Table 3. National Ambient Air Quality Standards for Criteria Pollutants ...

United States Congress, Public Eaw 101-549, MnMct toMmend the Clean Air Met to Provide for Attainment and Maintenance of Health Protective National Ambient Air Quality Standards, andfor Other Purposes, Nov. 15,1990. 

National Ambient Air Quality Standards. Under the Clean Air Act, six criterion pollutants, ie, pollutants of special concern, have been estabhshed by the EPA sulfur oxides (SO ), particulates, carbon monoxide (CO), nitrogen oxides (NO ), o2one (photochemical oxidants), and lead. National Ambient Air QuaUty Standards (NAAQS) were developed by EPA based on threshold levels of air pollution below which no adverse effects could be experienced on human health or the environment. 

ERA promulgated the basic set of current ambient air-quality standards in April 1971. The specific regulated pollutants were particulates, sulfur dioxide, photochemical oxidants, hydrocarbons, carbon monoxide, and nitrogen oxides. In 1978, lead was added. Table 25-1 enumerates the present standards. 

Prevention of Significant Deterioration (PSD) Of aU the federal laws placing environmental controls on industiy (and, in particular, on new plants), perhaps the most confusing and restrictive are the limits imposed for the prevention of significant deterioration (PSD) of air quahty. These limits apply to areas of the countiy that are already cleaner than required by ambient air-quality standards. This regula-toiy framework evolved from judicial and administrative ac tion under the 1970 Clean Air Act and subsequently was given full statutoiy foundation by the 1977 Clean Air Act Amendments. 

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

The terms ambient air, ambient air pollution, ambient levels, ambient concentrations, ambient air monitoring, ambient air quality, etc. occur frequently in air pollution parlance. The intent is to distinguish pollution of the air outdoors by transport and diffusion by wind (i.e., ambient air pollution) from contamination of the air indoors by the same substances. 

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. 

The relationship of these response curves to ambient air quality is shown by lines A, B, and C, which represent the maximum or any other chose percentile line from a display such as Fig. 4-10, which shows actual air quality. Where the air quality is poor (line A), essentially all the adverse effects displayed will occur. Where the air quality is good (line C), most of the intermediate and long-term adverse effects displayed will not occur. Where the air quality is between good and poor, some of the intermediate and long-term adverse effects will occur, but in an attenuated form compared with those of poor air quality. These concepts will be referred to later in this text when air quality standards are discussed. 

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. 

IDENTIFICATION AND QUANTIFICATION.—Such plan provisions shall expressly identify and quantify the emissions, if any, of any such pollutant or pollutants which will be allowed, from the construction and operation of major new or modified stationary sources in each such area. The plan shall demonstrate to the satisfaction of the Administrator that the emissions quantified for this purpose will be consistent with the achievement of reasonable further progress and will not interfere with the attainment of the applicable national ambient air quality standard by the applicable attainment date. 

Public Law 101-549, 101st Congress—November 15, 1990, An Act to Amend the Clean Air Act to provide for attainment and maintenance of health protective national ambient air quality standards, and for other purposes. 

Fig. 14-1. Nondispersive infrared (NDIR) analyzer, Source Bryan, R. J, Ambient air quality surveillance, in "Air Pollution," 3rd ed., Vol. Ill (A. C. Stern, ed.). Academic Press, New York, 1976, p. 375.

Describe the rationale for the U.S. Environmental Protection Agency s establishment of a standard reference method for measurement of National Ambient Air Quality Standard air pollutants. 

The U.S. Environmental Protection Agency has established National Ambient Air Quality Standards (NAAQS) for protection of human health and welfare. These standards are defined in terms of concentration and hme span for a specific pollutant for example, the NAAQS for carbon monoxide is 9 ppmV for 8 hr, not to be exceeded more than once per year. For a state or local government to establish compliance with a National Ambient Air Quality Standard, measurements of the actual air quality must be made. To obtain these measurements, state and local governments have established stationary monitoring networks with instrumentation complying with federal specifications, as discussed in Chapter 14. The results of these measurements determine whether a given location is violating the air quality standard. 

Code of Federal Regulations, Title 40, Part 58, Ambient Air Quality Surveillance, Appendix D— Network Design for State and Local Air Monitoring Stations (SLAMS). U.S. Government Printing Office, Washington, DC, July 1992, pp. 158-172. 

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

Sources Air Quality Criteria for Particulate Matter and Sulfur Oxides, final draft, U.S. Environmental Protection Agency, Research Triangle Park, NC, December 1981 Review of the National Ambient Air Quality Standards for Sulfur Oxides Assessment of Scientific and Technical Information, Draft OAQPS Staff Paper, U.S. Environmental Protection Agency, Research Triangle Park, NC, April 1982. 

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... 

Annual geometric mean United States Secondary National Ambient Air Quality Standard as of September, 1987... 

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 Canadian Clean Air Act allows the minister to formulate air quality objectives reflecting three ranges of ambient air quality for any contaminant. The tolerable range denotes a concentration that requires abatement without... 

For many industrialized countries, efforts to improve the outdoor air quality have been under way for the majority of this century. In many locations around the world, significant improvements have taken place. Air quality in many major cities such as London, New York, and Chicago has improved from the conditions present in the first half of the twentieth century. Mechanisms and control programs are in place in the developed countries to continue the improvement of ambient air quality. Considerable effort and energy have been expended to characterize, evaluate, and control air pollution emissions to the atmosphere. 

The concentration of indoor pollutants is a function of removal processes such as dilution, filtration, and destruction. Dilution is a function of the air exchange rate and the ambient air quality. Gases and particulate matter may also be removed from indoor air by deposition on surfaces. Filtration systems are part of many ventilahon systems. As air is circulated by the air-conditioning system it passes through a filter which can remove some of the particulate matter. The removal efficiency depends on particle size. In addition, some reactive gases like NOj and SOj are readily adsorbed on interior surfaces of a building or home. 

These regulahons will apply to an estimated 34,000 "major" industrial sources. "Major" sources are defined according to their "potential to emit" and the cutoff levels vary depending on both the pollutant and the local areas compliance status with the National Ambient Air Quality Standard (NAAQS) for that pollutant. For the present, the EPA has exempted all "nonmajor" sources, of which there are estimated to be about 350,000, from this permithng, unhl they have studied further the feasibility of permithng them. However, the states can require permitting of some of these sources. 

Some variants of best practicable means are spelled out in the U.S. Clean Air Act of 1977. One is the requirement that best available control technology (BACT) for a specific pollutant be employed on new "major sources" that are to be located in an area that has attained the National Ambient Air Quality Standard (NAAQS) for that pollutant. BACT is also required for pollutants for which there is no NAAQS [e.g., total reduced sulfur (TRS), for which emission limits are specified by a Federal New Source Performance Standard (NSPS)]. BACT must be at least as stringent as NSPS but is determined on a case-by-case basis. 

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