A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science

Thesis (M.Sc.) - Asian Institute of Technology, 1992

Air pollution emission inventories have been made for both Kathmandu Valley and Nepal. In Kathmandu Valley, major sources of air pollution emission have been identified and quantified on the basis of energy utilization. Estimation of air pollutants has been made for both types; conventional pollutants, oxides of carbon, nitrogen and sulfur, and carcinogenic compounds. Exhaust emission, from public transportation services in the valley on different city routes, has been estimated according to vehicle miles travelled. Peak hour exhaust emission of different types of vehicles and in different urban localities, has been computed. Since the peak hour vehicle volume of privately owned gasoline powered light vehicles is higher than heavy duty diesel vehicles of mass transit system, exhaust emission from different types of vehicles around the commercial center is higher than m residential and hospital environments. The contribution of air pollution from the stationary sources has been estimated. Brick and cement factories, and traditional potters contribute significant amounts of pollutants. The average annual energy use and emission of pollutants by these factories have been estimated. · Annual contribution of C02 by different energy utilizing sources is on-road vehicles (public transportation services only) 706 tons, landing and take off of aircraft 186 tons, individual brick factory 43 tons, a single updraft kiln 5 tons, and cement factory 5778 tons. It has been estimated that emission rate of NOx in Kathmandu Valley is public transportation services 269 tons, LTO of aircraft 82 tons, each brick kilns 6 tons, and cement factory 40 tons, per year. Similarly, annual contribution of SOx is public transportation services 28 tons, annual LTO 5 tons, an individual brick factory 5 tons and cement factory 20 tons. In the national context, major sources of green house gases have been identified. Deforestation and land use change contribute a significant amount of carbon dioxide. Cattle and other animals, and paddy field are the major sources of methane. Installment of pollution control technologies in every pollution emission sources is a primary suggestion. It is essential to check further deforestation and land use change. Fuel switch from traditional energy sources to hydropower is the clean option for future.