1. Kathmandu Valley in Nepal has high levels of air pollution that pose serious health risks to its 1.7 million residents. Vehicular emissions are a major cause of the pollution. 2. Air quality monitoring shows pollution levels in Kathmandu often exceed WHO guidelines. The level of PM2.5 in the air is over 100 micrograms per cubic meter on average. 3. A citizen science program is helping residents track and report air quality around the valley through a mobile app that uses stickers as tags to identify locations and transmit air quality data.

2. --Kathmandu Valley on a polluted day
--Stockholm Environment Institute
--Kathmandu Valley on a clear day

3. 1 KILOMETER

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