Over the past two decades the issue of air pollution in the
Kathmandu Valley has become of increasing concern as
concentrations of ambient air pollution exceed international
air quality guidelines and standards. The steady growth in
road traffic has resulted in the increasing contribution of
vehicle emissions to urban air pollution, especially particulate
matter (PM), volatile organic compounds, polycyclic
aromatic hydrocarbons (PAH), carbon monoxide (CO), and
nitrogen oxides (NOx). The serious air pollution challenges in Kathmandu Valley call for rapid approaches to assess the problem and derive solutions which are politically viable, low-cost and realizable in a step-wise way.