- nitrogen oxides
- hydrocarbons and
- oxygen
The citizens of Los Angeles suffer from the worst air pollution
in the United States. Pollution reaches unhealthful levels on roughly half
the days each year--as opposed to 279 days in 1976--causing irritation
for many and illness for some. A 1991 study found that those living in
areas where particulate pollution exceeded government standards for 42
days per year or more had a 33 percent greater risk of contracting bronchitis
and a 74 percent greater risk of contracting asthma.
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These secondary pollutants are damaging to plant life and lead to the formation of photochemical smog. PAN is primarily responsible for the eye irritation so characteristic of this type of smog.
Los Angels is suitable for photochemical pollution, because several
additional ingredients contribute to the city's air pollution problems.
Besides the abundant sunshine that drives photochemical reactions, low
average wind speeds, and rapid growth in the numbers of people, cars, and
factories would cause it happen. From 1950 to 1990, the region's population
grew from 4.8 million to 14 million; the vehicle population jumped from
2.3 million to 10.6 million.
In an effort to improve air quality, state and regional agencies
are implementing a stringent and innovative pollution control effort that
targets industry, transportation, and consumers. The political arrangements
have evolved over many decades.
The catalytic converter in automobile exhaust systems reduces air pollution by oxidizing hydrocarbons to CO2 and H2O and, to a lesser extent, converting nitrogen oxides to N2 and O2.
California legislature in 1976 created the South Coast Air Quality Management District and gave it jurisdiction over much of the air quality throughout the four counties--Los Angeles, Orange, and parts of Riverside and San Bernardino counties. The District was given responsibility for stationary sources of air pollution, which include about 31,000 businesses ranging from large power plants to small gas stations and which account for about 40 percent of the area's pollution. Also under the District's purview are consumer products, such as house paint, charcoal lighter fluid, and products containing solvents. The District's air quality plans must be approved by the California Air Resources Board (CARB) and then by the U.S. Environmental Protection Agency. CARB also was given jurisdiction over mobile sources of pollution such as cars, trucks, and buses.
Even so, if Los Angeles is to meet federal health standards by 2010, more stringent requirements will be needed. Hydrocarbon emissions must be cut by about 80 percent, nitrogen oxides by 70 percent, sulfur oxides by 62 percent, and particulates by 20 percent. To meet the 2010 deadline, the District has devised an elaborate two-stage air quality management plan, relying on both current technologies and some that do not yet exist. The first stage includes some 135 different measures, all using existing technologies that can be adopted by 1996. The second stage will take advantage of technologies that are just entering the commercial market, such as a new house paint that does not release hydrocarbons and automobile engines that run on methanol, natural gas, or other alternative fuels. The District has invested over $40 million in seed money to support new technologies.
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