It is estimated that air pollution costs about US$4 million per year in medical costs for Kathmandu residents. Kathmandu Valley's bowl-like topography and low wind speeds during winter create poor dispersion conditions, which predisposes the area to serious air pollution problems.

The World Bank's Urban Air Quality Management Strategy (URBAIR) Kathmandu Valley Report (1997) estimated that air pollution is the cause of about 85 pollution-related premature deaths, with estimated health damage costs of Rs. 210 (US$4.4) million a year.