Smoke and other emissions from stationary and mobile sources.

Abstract

Although most of the world's cities and industrial regions have been plagued with air pollution for centuries, there was little organized effort to combat the problem until the mid-20th century. Even though everyone is aware of the air pollution problem, it is now well understood that, in today's world this problem can never be totally solved, but at least changes are being done and slowly we are managing to control smoke and the other emissions.