Ambient air quality standard for lead

An important aspect of air pollution control in the US, but not in Europe, is the ambient air quality standard. This is the concentration of a pollutant which should not be exceeded in the interests of public health. After a heated debate over some years, the US Environmental Protection Agency has recently set an ambient air quality standard for lead of 1.5 jug m averaged over a calendar quarter [11]. 

Monitoring will be performed in all urbanized areas with a 1970 population exceeding 500000 and in areas where ambient lead levels currently exceed 1.5 Mg ni . Sampling will be carried out at three types of site [16]  

These are located adjacent to major highways, and placed between 5 and 15 m from the closest traffic lane. Monitors will be sited close to residences and not more than 5 m above ground level. 

These are located in an area of high traffic density and high population density, but not necessarily adjacent to a major road. The monitors will be sited at least 15 m from the nearest road with more than 2000-3000 vehicles day Monitors should be not more than 5 m above ground level. It is desirable for monitors to be placed in areas which children frequent, and for siting to expose the monitor to both mobile and stationary sources of lead. 

These are located in areas of high traffic and population density. Monitors will be sited in city centre streets of high traffic density lined with high buildings and should be sited at no more than 5 m above ground level. 

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EPA. 1989g. Review of the national ambient air quality standard for lead Exposure analysis, methodology and validation. OAQPS staff report. Research Triangle Park, NC U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards. EPA-450/2-89-011. 

Data from Air Quality Criteria for Lead, EPA 600/8-77-017, Dec. 1977, special series. United States Environmental Protection Agency, Research Triangle Park North Carolina National ambient air quality standards for lead, final rules. Fed. Reg. (Part IV), Oct 5, 1978, pp. 46246-46277. 

After attributing a blood lead level of 12 /tg/dl to nonairbome ingested sources (i.e., food, water, soil, paint), this leaves 3 /tg as the maximum safe contribution from inhaled air. Assuming airborne lead (/tg Pb/m air) as 0.5 blood lead, this yields a safe air quality level of 1.5 /tg Pb//tg air, which was promulgated as the U.S. national ambient air quality standard for lead, as the maximum arithmetic mean averaged over a calendar quarter. 

US Environmental Protection Agency (1978), National Ambient Air Quality Standard for Lead, Federal Register, 43,46246-77. 

In the US lead-free gasoline has been widely available since 1974. It must, by law, be used in all new cars of 1975 or later model year and is required to prevent poisoning of oxidation catalysts fitted to the exhaust systems of those cars to meet Environmental Protection Agency emission standards for carbon monoxide and hydrocarbons. More recently, measures have been introduced to phase down the lead content of gasoline as a pre-requisite to the achievement of the ambient air quality standard for lead (Section 5.5). 

U.S. Environmental Protection Agency, 2008b. Office of the Administrator. National Ambient Air Quality Standards for Lead. Final Rule. Federal Register 73 FR 66964-67062,... 

U.S. Envirorunental Protection Agency, 1978. National Primary and Secondary Ambient Air Quality Standards for Lead. 43 FR 46246-46263, October 5, 1978. 

Fahim, M.S., Fahim, Z. and Hall, D.G. (1976). Effects of subtoxic lead levels on pregnant women in the state of Missouri. Res. Commun. Chem. Pathol. Pharmacol, 13, 309-331 Federal Register (1978). National ambient air quality standard for lead final mles and proposed mlemaking. Fed. Reg., 43 (October 5), 46246-46263 Fejerman, N., Gimenez, E.R., Vallejo, N.E. and Medina, C.S. (1973). Lennox s syndrome and lead intoxication. Pediatrics, 52, 227-23A... 

National primary and secondary ambient air quality standards for lead. 1987. 40 CFR 50.12 (latest amendment 52 FR 31701)... 

Between 1980 and 1994, five European directives on ambient air quality standards were adopted. In December 1982, ambient air quality levels for lead - as one of the most abundant air pollutants - was established (Council directive 82/884/EWG 1982) and transferred into national law of the European member states. 

EPA considers the photochemical reactivity of tetrachloroelhylene leading to the production of ambient ozone to be negligible (EPA 1996a). Therefore, tetrachloroethylene has been added to the list of compounds excluded from the definition of volatile organic compounds for purposes of preparing state implementation plans to attain the national ambient air quality standards for ozone. 

U.S. Environmental Protection Agency, Air and Radiation, National Ambient Air Quality Standards (NAAQS) http //www.epa.gov/air/criteria.html (accessed October 13,2010). The Clean Air Act requires EPA to set National Ambient Air Quality Standards for pollutants considered harmful to public health and the environment. The EPA Office of Air Quality Planning and Standards (OAQPS) http //www.epa.gov/air/oaqps/ (accessed October 15, 2010) has set National Ambient Air Quality Standards for six principal pollutants (ground level ozone, lead, carbon monoxide, sulfur dioxide, nitrogen oxides, and respirable particulate matter), which are called criteria pollutants. 

In July 1993, Vermont unilaterally reduced its air quality standard for lead to 0.25 pgfm , the first US state to establish an ambient standard below the national standard. 

Air quality standards. The Environmental Protection Agency EPA has established health-based National Ambient Air Quality Standards (NAAQS) for six pollutants carbon monoxide, ozone, nitrogen oxide, sulfur dioxide, particulate matter, and lead. The current NAAQS are presented in Table 7.9. (US EPA, 1993). 

Criteria pollutants are air pollutants (e.g., lead, sulfur dioxide, and so on) emitted from numerous or diverse stationary ormobile sources for which National Ambient Air Quality Standards have been set to protect human health and public welfare. 

Criteria pollutants are air pollutants emitted from numerous or diverse stationary or mobile sources for which National Ambient Air Quality Standards have been set to protect human health and public welfare. The original list of criteria pollutants, adopted in 1971, consisted of carbon monoxide, total suspended particulate matter, sulfur dioxide, photochemical oxidants, hydrocarbons, and nitrogen oxides. Lead was added to the list in 1976, ozone replaced photochemical oxidants in 1979, and hydrocarbons were dropped in 1983. Total suspended particulate matter was revised in 1987 to include only particles with an equivalent aerodynamic particle diameter of less than or equal to 10 micrometers (PM10). A separate standard for particles with an equivalent aerodynamic particle diameter of less than or equal to 2.5 micrometers (PM25) was adopted in 1997. 

Clean Air Act (CAA 42 U.S. Code 7401 et seq.). States and state air control boards are required to implement regulations and develop state implementation plans (SIP) (137). Hazardous air pollutants (HAP), such as n-hexane, are regulated with National Emissions Standards for Hazardous Air Pollutants (NESHAP) and criteria pollutants [e.g., ozone (O3), particulate matter (PM), nitrogen oxides (NOx), sulfur oxides (SOx), carbon monoxide (CO), and lead (Pb)] are regulated with National Ambient Air Quality Standards (NAAQS). 

The American 1970 Clean Air Act defined ambient air quality standards (NAAQS) in the United States for atmospheric ozone, NO, lead, carbon monoxide, sulfur oxides, and PM-10 (particulate matter less than 10 p.m). The strategy to reduce levels of lead, NOx, PM-10, and to some extent carbon monoxide was to control emissions from automobiles that included the phasing-out of leaded fuel. As previously noted, ozone is a product of the photochemical reaction of volatile organic compounds with NOx (photochemical smog), so the balance between organic compounds and NOx pollutants is important in meeting target ozone levels (e.g., 0.12 ppm). Emissions from stationary sources is an important factor, and limits have been set for them. Because of low pressure drop requirements, coated monolithic catalysts... 

Reductions in ambient concentrations of some but certainly not all air pollutants have taken place over the past decade. In the United States, the US Environmental Protection Agency (EPA) is the primary agency responsible for promulgating and regulating air pollution standards. National ambient air quality standards (NAAQS) have been established for six classes of outdoor pollutants lead, carbon monoxide, ozone, nitrogen dioxide, sulfur dioxide, and particulate matter. These standards (Table 1) are periodically reviewed and updated based on currently available data regarding adverse health effects. Bases on new evidence, the standards for ozone and... 

National Ambient Air Quality Standards (NAAQS) have been established for ozone (qv), nitrogen oxides, lead (qv), carbon monoxide (qv), sulfur dioxide, and particulates. The standards have been set to safeguard human health and the environment. Many areas of the country violate one or more of the NAAQS. To achieve healthful air for all citizens, the states establish an implementation plan for each area that violates the NAAQS for any of the six criteria pollutants. The plan is a strategy designed to achieve sufficient emission reductions to meet the NAAQS within the deadline. Based on the implementation plan, specific regulations are written which govern the operations emitting the pollutant. 

Slovak Republic in the framework of the PHARE Project (1996-1997) (Table 7). Considering the situation in Slovakia, all the mean levels from all the sampling sites were below the annual National Ambient Air Quality Standards (0.5 p.g/m ) and guideline by WHO. Comparison with typical values for atmospheric lead levels in Europe indicates that, in general, the levels measured in Slovakia are at the lower end of typical European levels (Ursmyova and Hladikova, 1998a). Cities in Slovakia show the relationship between the decreasing use of lead in gasoline and the decline in airborne lead concentrations (Fig. 2) (Violova et al., 1997). 

The annual arithmetic concentrations for lead in all the 27 studied localities of the Czech Republic were below the National Ambient Air Quality Standard 0.5 p.g/m (Table 8). The highest values were found in Ostrava, Karvina, Brno and Kladno -above 0.1 p.g/m (National Institute of Public Health in Prague, 1995a). 

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