The U.S. Environmental Protection Agency (EPA) is responsible for the regulation of ozone under the criteria of air pollutants in the Clean Air Act. The goal of the Clean Air Act is to regulate air pollutants, such as ozone, in order to manage the health impact. The most recent (2008) National Ambient Air Quality Standard (NAAQS) for ozone was set at 0.075 parts per million (ppm) for an 8 hour averaging time . Area designations for the 1997 ground-level ozone standards became effective in 2004. Counties in the United States are designated by EPA as “attainment” or “nonattainment” according the standards working in conjunction with the states and the tribes. States are federally required (under the Clean Air Act, Section 110) to develop State Implementations Plans (SIPs) to attain and maintain the NAAQS in ozone nonattainment areas that include “monitoring, modeling, emission inventories, control strategies .”
EPA has designated Los Angeles as nonattainment in Region 9, according to April 15, 2004 Classification, ozone pollution in Los Angeles South Coast Air Basin was in severe level . EPA assisted state/local agencies preparing revised ozone plan. Los Angeles is currently classified as the only “extreme” nonattainment area in the nation. The 8-hour ozone standard design value by EPA’s request for recommendations on the designations of areas for Western Los Angeles (including Catalina and San Clemente Islands) was 0.147 ppm and 0.128 ppm in 2000 and 2003, respectively.
On July 26, 1943, in the midst of World War II, Los Angeles was attacked — not by a foreign enemy, but domestic one — smog. Region’s industrial base was dramatically increased by WWII, and thus resulted in air pollution. The city’s population and motor vehicle fleet grew rapidly as well. As a result, smog increased and visibility declined rapidly from 1939 to 1943. Since the dawn of the war on smog, government agencies initiated a lot of efforts during the past years toward clean air in Los Angeles. Some examples are :
- The Los Angeles County Board of Supervisors established the nation’s first air pollution control program by creating the Los Angeles County Air Pollution Control District (APCDs) in Orange County in 1950, and in Riverside and San Bernardino counties in 1957. Twenty years later, the four county agencies were combined to form the South Coast Air Quality Management District (AQMD).
- The early smog control efforts by the air pollution officials made significant strides in reducing smoke and fumes by regulating open burning in garbage dumps, reducing smoke from factories and cutting sulfur dioxide emissions from oil refineries. These measures reduced the “dustfall” by two-thirds, to 1940 levels before smog was a serious problem.
- In 1953, modern pollution control strategies were recommended: Hydrocarbon emissions be reduced by cutting vapor leaks from refineries and fueling operations; Automobile exhaust standards be established; Diesel trucks and buses burn propane instead of diesel; Heavily polluting industries consider slowing their growth; and open burning of trash be banned.
- In 1959, the California Motor Vehicle Pollution Control Board was created with authority to test emissions and certify emission control devices. The board focused first on reducing unburned hydrocarbon emissions from engine crankcases, and required that starting with the 1963 model year, new cars be equipped with a device that routed crankcase “blowby” gases to the manifold, where they were re-burned, rather than venting them to the atmosphere.
- In the late 1960s, California imposed initial regulations reducing cars’ tailpipe emissions. The most significant pollution control device — the catalytic converter — was not required until the 1975 model year.
- In the 1960s, regulators took the first step in cleaning up motor vehicle fuels by reducing the amount of highly photochemically reactive olefins in gasoline.
- During the 1970s and 1980s, California environmental agencies advocated the use of methanol and natural gas instead of gasoline, which could cut a vehicle’s smog-forming emissions in half. Also the threat of an alternative fuel mandate motivated oil companies to significantly clean up gasoline.
- In the early 1980s, ARCO introduced the first reformulated gasoline with fewer smog-forming and toxic ingredients. The California Air Resources Board and the U.S. Environmental Protection Agency have since required all oil companies to develop and sell even cleaner gasoline.
- In 1987, AQMD’s Governing Board required employers with more than 100 employees to offer tangible incentives to employees to carpool and ride public transit to work. For eight years, the program achieved marked success, reducing 272,000 trips per day.
- AQMD in 1993 adopted RECLAIM, the REgional CLean Air Incentives Market. The program includes about 330 of the largest emitters of nitrogen oxides and sulfur oxides, combustion byproducts that form ozone and particulate pollution.
- In 1988, AQMD established its Technology Advancement Office to help private industry speed up the development of low- and zero-emission technologies. Major developments focus on NOx and VOC emission reduction, which include: Fuel cells, Electric vehicles, Zero-VOC paints and solvents, Remote sensing to identify and repair high-emitting vehicles, Alternative fuel heavy-duty vehicles and locomotives.
- AQMD has helped sponsor several projects demonstrating the use of clean fuels, such as compressed natural gas in heavy-duty trucks and transit buses. AQMD also is contributing to research to develop a liquid natural gas-powered locomotive. Diesel locomotives in the region are responsible for more than 31 tons per day of NOx emissions.
In many ways, the state of California and the city of Los Angeles have proved to be leading the environmental air quality policy innovations, and outreach. California is the only state that has power to regulate emissions from vehicles under the Pavley Bill . The county tax was increased by 0.5 cents to support transportation infrastructure from November 2008 . Despite some drawbacks, like less priority for implementation of adaptation strategies, L.A. with its leadership, policy innovation, commitment, partnerships and social capital sets as best example of how a city can go beyond a nation’s effort with many win- win strategies during these hard times.
With all the efforts mentioned above, peak ozone concentrations have decreased by more than 60 percent and smog alerts no longer occur in the Los Angeles area. According to EPA Progress Report 2003, the Los Angeles area (the red line) has made great progress toward clean air in the past decade, despite the double increasing in population and almost tripling in vehicle miles traveled .
In April 2005, the Air Resources Board approved a new eight-hour standard of 0.070 ppm and retained the one-hour ozone standard of 0.09 ppm . However, most Californians still live in areas that do not attain the State’s health-based standard for ozone in ambient air and Los Angeles is yet still the number 1 rank of most ozone-polluted cities in US .
 U.S. Environmental Protection Agency. 2008. National Ambient Air Quality Standards for Ozone: Final Rule 40 CFR Parts 50 and 58. Federal Register, 73:16436-16514.
 U.S. Environmental Protection Agency. Ozone Implementation – Programs and Requirements for Reducing Ground-level Ozone.
 U.S. Environmental Protection Agency. Ground Level Ozone Standards Designation.
 The Southland’s War on Smog: Fifty Years of Progress Toward Clean Air (1997)
 Climate Action Team, (2010), Climate Action Team Report to Governor Schwarzenegger and the California Legislature
 City of Los Angeles (2008), ClimateLA. Municipal Program Implementing the GreenLA Climate Action Plan Executive Summary.
 EPA Progress Report 2003 Pacific Southwest Region.
 Ozone and Ambient Air Quality Standards (2008).
 American Lung Association, Most Polluted Cities.