In developing countries problem of industrialization, modernization and increasing population degrades the society with polluted air. Moreover, concentration of pollutants increases day by day with addition of harmful gases from exhaust of motor vehicles and industrial sources. With passage of time, people realized that polluted outdoor air has serious effects on their health. Outdoor air pollution is nuisance challenge for public health hazards like cardiovascular disease, respiratory diseases, chronic obstructive pulmonary disease (COPD) and asthma which spread throughout the world. The broad overview of the status of and trends in outdoor air pollution sources, pollutants, and exposures and its health effects are presented. Considering all factors, the goal of the present review is to draw together results from different investigations and present a picture of our current understanding of relationship between outdoor air pollution and health and to inform people about the health effects of outdoor air pollution and to provide an approach to counseling vulnerable people in order to reduce exposure.
