Air pollution has been further divided into indoor air pollution and outdoor air pollution. There are many causes of each of these types. Outdoor air pollution results due to the release of gases from the industries into the air. This results in contaminating the air. This is also true for the emissions from motor vehicles. Furthermore, the usage of insecticides and pesticides also serves to add contaminants to the air. Accidents in nuclear power plants may also result in the release of toxic gases which may pollute the air. Indoor air pollution results due to the burning of coal, oil and wood in the houses. It mainly implies for the rural areas of the developing nations of the world. Cigarette smoking is another factor which leads to the addition of harmful gases to the atmosphere (Park 2007). Air pollution is a serious global issue that needs to be tackled. Different methods and ways have been devised to overcome this problem. The World Health Organization has presented with different solutions that need to be put into action to overcome air pollution.