Many major cities throughout the United States, as well as throughout the world, suffer from pollution because of the dense population and reliance on automobiles, airplanes, locomotives, shipping, and other sources that spew carbon dioxide into the air. This causes water pollution and air pollution, often in the form of smog, to greatly threaten the environment and health of the city’s residents. Los Angeles is one of these large cities that suffers from air and water pollution, in fact, it is one of the most polluted cities in the nation. The city’s geographical location also increases the problems of pollution because the Los Angeles Basin is susceptible to atmospheric inversion, where the smog is trapped and wind and rain has trouble getting rid of the smog.
Los Angeles’s smog can be contributed to mostly by the exhaust from automobiles, and the city’s groundwater is also threatened by MTBE from gas stations, as well as the perchlorate from rocket fuel. Nevertheless, the city has taken drastic measures to reduce these environmental problems by passing legislation such as the Clean Air Act and mandating low emission vehicles. In fact, the number of Stage 1 smog alerts has greatly declined from over 100 per year in the 1970’s to nearly zero in the current decade.