Since the
onset of the industrial revolution, there has been a steady change in the
composition of the atmosphere mainly due to the combustion of fossil fuels used
for the generation of energy and transportation.
Air
pollution is a major environmental health problem affecting the developing and
the developed countries alike. The effects of air pollution on health are very
complex as there are many different sources and their individual effects vary
from one to the other. It is not only the ambient air quality in the cities but
also the indoor air quality in the rural and the urban areas that are causing
concern. In fact in the developing world the highest air pollution exposures
occur in the indoor environment.