Describe air quality conditions in the US before steep regulations were imposed.
The United States has experienced the worst air quality conditions during the 1940s and 1950s as an effect of the progressing industrialization and urbanization. Another main reason is that the United States has no national regulation and policy towards hazardous gas emission and air pollution during these periods of time. During the 1940s and 1950s, the United States have experienced deadly photochemical smog on major cities including Los Angeles and Donora(Williams, 2013). In addition, the ozone levels in the lower layers of the atmosphere exceed its limit and become dangerous to people as well as the environment. During ...
