With the existence of high urban area pollution levels it is important to consider the public health effects which led to the implementation of emissions control programs. Carbon monoxide enters the bloodstream through the lungs and forms carboxyhemoglobin, a compound that inhibits the blood's capacity to carry oxygen to organs and tissues. Persons with heart disease, infants, elderly and individuals with respiratory diseases are especially sensitive to carbon monoxide poisoning. Although high CO levels, such as in urban areas, can also affect healthy individuals, impairing exercise capacity, visual perception, manual dexterity, and learning functions. High levels of emissions by other pollutants also increase the risks of respiratory problems, heart related problems, increased rates of cancer and neurological diseases. In 1992, carbon monoxide levels exceeded the Federal air quality standard in twenty US. cities affecting more than 14 million people. (EPA Automobiles).
Legislative Action Taken to Reduce Emissions.
The 1970's Clean Air Act (CAA) and the 1990 Clean Air Act Amendments (CAAA) gives state and local governments primary responsibility for regulating pollution from power plants, factories, and other "stationary sources." The Environmental Protection Agency has the primary responsibility for "mobile source" pollution control.
In 1975, resulting from EPA intervention, automobile manufacturers were successful in designing more environmentally sound vehicles with the advent of the catalytic converter, which converts carbon monoxide to carbon dioxide, CO levels were reduced by approximately eighty percent. Further advances were made in 1981 with more sophisticated "three-way" catalyst converters (which convert carbon monoxide and hydrocarbons to carbon dioxide and water and also helps reduce nitrogen oxides to elemental nitrogen and oxygen)and an increased use of computers to regulate efficiency.
