Polution

Industrialisation and poverty are two major contributors leading to two different issues of air pollution; outdoor air pollution and indoor air pollution respectively. Basically, developed countries are concerned about outdoor air pollution, as; indoor air pollution is not a major issue in their context. Developing countries like Nepal are at double jeopardy; as the problem of outdoor as well as indoor air pollution is growing fast, and those pollutions are interchangeable.

Rapid progress in industrialization and mechanization has resulted in unlimited exploitation of natural resources, and in the absence of air pollution control mechanism, it has resulted in serious outdoor air pollution problems in Nepal. In our country, outdoor air pollution is a problem in the major cities like Kathmandu valley. The main sources of air pollution in Kathmandu are industries and vehicles. Other minor sources are domestic cooking fuels, refuse burning and resuspended dust particles. A study done by the World Bank in 1993 estimated that the contribution of vehicle exhaust to Total Suspended Particulate was only 3.5 percent compared to contribution of Himal Cement Factory (36%), brick kilns (31%) and domestic fuel combustion (14%). However, the situation in Kathmandu is quite different now. Himal Cement Factory along with other different industries has closed for different reasons and many people use less polluting cooking fuels like kerosene and LPG instead of biomass. But in the mean time, the number of vehicles in the valley has increased threefold. The emission from the vehicles has therefore probably increased significantly, while emission from other sources has decreased over the past 10 years. As a result, vehicle is now the number one source of pollution in Kathmandu. The main reason for the high level of vehicular emission is the large number of poorly maintained vehicles on congested streets, poor quality fuels and lubricants, weaknesses in the emission inspection & maintenance system and a poorly managed transportation system. Vehicles are the main sources of air pollution in Kathmandu as the places with heavy traffic (Putali Sadak and Patan Hospital) are the most polluted and the pollution levels drop significantly on weekends and during ''bandhs'' or strikes when there are fewer vehicles on the road.

Whereas, the major source of indoor air pollution in Nepal is biomass fuel. About 50 % of the world''s population is estimated to use solid bio-fuels like animal dung, crop residues, wood and coal for cooking daily meals and heating homes. The census 2001 report In Nepal shows that 80 % of households depend upon solid bio-fuels for domestic uses. is considered to be a significant source of public health hazard, particularly to the poor and vulnerable women and children.