Toxic air

Methanol use would also reduce pubHc exposure to toxic hydrocarbons associated with gasoline and diesel fuel, including ben2ene, 1,3-butadiene, diesel particulates, and polynuclear aromatic hydrocarbons. Although pubHc formaldehyde exposures might increase from methanol use in garages and tunnels, methanol use is expected to reduce overall pubHc exposure to toxic air contaminants. 

Although considerable federal legislation dealing with air pollution has been enacted since the 1950s, the basic statutory framework now in effect was established by the Clean Air Act of 1970 amended in 1974 to deal with energy-related issues amended in 1977, when a number of amendments containing particularly important provisions associated with the approval of new industrial plants were adopted and amended in 1990 to address toxic air pollutants and ozone nonattainment areas. 

The 1990 CAAA introduced a new level of control for hazardous (toxic) air pollutants (HAPs). As a result, EPA has identified 189 HAPs for regulation. Rather than rely upon ambient air qnahty standards to set acceptable exposures to HAPs, the CAAA requires that EPA promulgate through the end of the decade Maximum Achievable Control Technology (MACT) standards for controlling HAPs emitted from specified industries. These standards are based on the level of control estabhshed by the best performing 12 percent of industries in each of the categories identified by EPA. 

Toxic air pollutants are pollutants which are hazardous to human health or the environment but which are not specifically regulated by the CAA. These pollutants are typically carcinogens, mutagens, and teratogens. The CAAA of 1977 failed to result in substantial reductions in the emissions of these harmful substances. 

The toxic air pollution problem is widespread. Information generated from the Superfund "Right to Know" rule From the Superfund Authorization and Recovery Act (SARA Section 313) indicates that more than 2.7 billion pounds of toxic air pollutants are emitted annually in the United States. EPA studies indicate that exposure to such quantities of air toxics may result in 1000 to 3000 cancer deaths each year. 

The CAAA90 offers a comprehensive plan for achieving significant reductions in emissions of hazardous air pollutants from major sources. The new law will improve EPA s ability to address this problem effectively and it will accelerate progress in controlling major toxic air pollutants. 

The law includes a list of 189 toxic air pollutants of which emissions must be reduced. The list of source categories includes (1) major sources emitting 10 tons/year of any one, or 25 tons/year of any combination of those pollutants and (2) area sources (smaller sources, such as dry cleaners). 

EPA, 1992, Work Book of Screening Techniques for Assessing Impacts of Toxic Air Pollutants. EPA-454/R-92-024, December. 

Criteria air pollutants Excluding carcinogenic particles and VOC s (included under luizardous/ toxic air pollutants) ranked low because reittainiitg criteria pollutaitts Itave not been shown to be carcinogens. 

Although the petrochemical and metals industries were the primai y focus of the toxic air pollutants legislation, approximately forty of these substances have been detected in fossil power plant flue gas. Mercury, which is found in trace amounts in fossil fuels such as coal and oil, is liberated during the combustion process and these emissions may be regulated in the future. EPA issued an Information Collection Request (ICR) that required all coal-fired plants to analyze their feed coal for mercury and chlorine. Since these data will be used in making a regulatory decision on mercury near the end ot the year 2000, it is critical that the power industry provide the most accurate data possible. 

Benzene is a known carcinogen. The U.S. Environmental Protection Agency (EPA) has identified benzene as a toxic air pollutant (TAP). Benzene is present in automotive evaporation, refueling vapors, and exhaust. 

The certification of fuels Each refiner, blender, or importer of gasoline must ensure that per-gallon emissions levels of VOCs, NOv, CO, and toxic air pollutants do not exceed the gasoline sold in 1990. 

Many attachments and special devices have been developed to extend and implement the applicability of the OM. One of these is a controlled atmosphere microscope dry-box which offers reproducible environmental control for applications involving toxic, air, or moisture sensitive ingredients, typical of many energetic materials (Ref 33)... 

D.T. Williams et al, Evaluation of Second Derivative Spectroscopy For Monitoring Toxic Air Pollutants , SAM TR-74-19, Proj AF-7164, Contract F 41609-73-C-0011 (1974)... 

California EPA. 2001. Evaluation of methyl parathion as a toxic air contaminant. Department of Pesticide Regulation, California Environmental Protection Agency. Http //www.cdpr.ca.gov 8765/. January 19, 2001. 

EPA. 1986b. Extension of the public comment periods on notices of intent to list trichloroethylene and perchloroethylene as potentially toxic air contaminants. U.S. Environmental Protection Agency. Federal Register 51 9510. 

Klaassen CD. 1985. Nonmetallic environmental toxicants Air pollutants, solvents, and vapors, and pesticides. In Gilman AG, Goodman LS, Rail TW, et al., eds. Goodman and Gilman s The pharmacological basis of therapeutics. 7th ed. New York, NY MacMillan Publishing Co., 1628-1637. 

Wallace LA, Pellizzari ED, Hartwell TD, et al. 1985. Personal exposures, indoor-outdoor relationships, and breath levels of toxic air pollutants measured for 355 persons in New Jersey. Atmos Environ 19 1651-1661. 

California maintains a list of Toxic Air Contaminants (TACs) and a program for adding additional TACs. 

Table 3 provides general guidelines used in toxic air assessments in California for sampling common agricultural pesticides in ambient air at near-field sampling monitors before, during, and shortly after a field application. For communities that are near the site of the candidate pesticide application, concurrent ambient air samples are taken over durations of 24 h and are collected 4 days per week for a period of 4 weeks. 

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