Air pollution may be due to a lot of factors, the most commons of which are caused by exhaust gases from vehicles, factory gas emissions, and natural events. Exhaust gases from vehicle have continuously dominated the air, especially in highly urbanized towns and cities, mainly because the government lacks control and citizens prefer convenience to the harmful effects. Likewise, the government has not exercised good control over the location of factories that emit gas elsewhere. Most often than not, air pollution is caused by natural events such as forest fires, volcanic eruptions, wind erosion and pollen dispersal. 3901 What is the paragraph about? What does the key sentence introduce? How many causes of air pollution are started ​