What Is Smog?
The term smog was first coined during the 1950s when it was used to describe a mixture of smoke and fog experienced in London. Major cities along the west coast of America were also experiencing a different type of air pollution.
Smog occurs when emissions from industry, motor vehicles, incinerators, open burning and other sources accumulate under certain climatic conditions. There are two types of smog: summer (the type of smog first experienced in America) and winter (the one first noticed in London).