e first contribution to the atmospheric pollution is natural disaster, causing great damage to human life, including as volcanic eruption and forest fire. Firstly, during a volcanic eruption, lava, ash and various gases are expelled then hung in the air and spread the nearby areas, resulting in many problems such as respiratory diseases or lack of food. For example, the 1815 eruption of mount Tamora made agricultural crops fail and livestock die, leading to one of the worst famine of the 19th century. Furthermore, erupting volcanoes do not only pose many hazards in the immediate vicinity but they also are a thread to the aircraft where ash particles are melted by the high temperature. Secondly, forest fire are happening on a large scale, losing thousand hectares of trees.
Much more important than natural disaster, the major reason of air pollution is because of various human activities. First and foremost, many communities contribute a great proportion to the level of pollution in the air. All over the world, factories of oil industry and chemicals industry discharge industrial waste as well as pollutants into the air. For instance, carbon dioxide is the main factor which brings about the air pollution but unfortunately, the manufacturing process of most products would require the use of this chemical. To make the matter worse, an increasing number of industries and manufac