Abstract : Air pollution is one of the biggest threats affecting all life forms including the environment. The major contribution to air pollution is introduction of harmful gases, particulates and biological molecules into the earth’s atmosphere causing diseases, allergies and even death to humans. Air pollutants cause immediate health problems, including aggravated cardiovascular and respiratory illnesses, stress to heart and lungs, damaging the cells in the respiratory system and also causing harm to other living organisms and food crops .Both human activity and natural processes can cause air pollution. This paper presents the issue of air pollution and discusses the latest findings of fundamental research with regard to its consequences on human health. The nature and sources of air pollution are also discussed.