Pollution in Kathmandu Valley poses a serious threat to both public health and the environment. Rapid urbanisation, poor infrastructure, and weak regulatory enforcement have made the Valley one of the world’s most polluted regions, particularly during the dry winter months.

Air pollution comes from multiple sources: outdated and poorly maintained vehicles, brick kilns, household fires, and seasonal stubble burning from northern India. The health impacts are severe, including respiratory and cardiovascular conditions, as well as eye and skin irritation.

Water pollution is equally alarming. Rivers are choked with untreated sewage, industrial effluents, and indiscriminate dumping of solid waste. Open spaces are often used as informal rubbish sites, adding to the degradation. Rapid urban expansion has also consumed green spaces and encroached on historic floodplains, further destabilising the valley’s natural systems.

Climate change has intensified these issues. The failure of winter rains worsens air pollution, while the rains, when they do come, tend to be heavier than in the past. This leads to dangerous flash flooding, exacerbated by the valley’s narrowed and obstructed waterways.