Data analysis of air quality monitoring stations set up last year in five places across the country shows that Lumbini is the most polluted city followed by Chitwan, Ratnapark (Kathmandu), Pulchowk (Lalitpur) and Dhulikhel (Kavrepalanchok). 

Data collected from the air quality monitoring stations between October and February showed presence of PM2.5 (fine particulate matter) in Lumbini five times higher than the World Health Organisation standard of 25 microgram per cubic metre (ug/m3) in a period of 24 hours. Nepal’s national air pollution standard is 40 ug/m3.

For the month of January, PM2.5 in Lumbini was measured at 173.035 ug/m3 followed by 113.32 ug/m3 in Chitwan and 109.08 ug/m3 in Ratnapark of Kathmandu. 

“Brick kilns and cement factories in the Lumbini-Bhairahawa Corridor produce pollutants,” said Arnico Panday, senior atmospheric scientist at the International Centre for Integrated Mountain Development (ICIMOD). Coal burning and burning of other stuff like tyres and tubes add to the problem.”

In 2013, 62 percent of air pollution in Lumbini was due to the flow of toxic air originated in India, while 24 percent of air pollution was created within Nepal. Polluted air from Bangladesh and Pakistan also played a crucial role in increasing pollution in the Tarai, according to data maintained by ICIMOD.

There are around 1,000 brick kilns in Nepal and around 30,000 in Uttar Pradesh and Bihar, two large bordering states in India. Toxic fumes produced by these brick kilns are collected in the skies and the wind blowing from those places bring about more fumes to the trans-border area making it tremendously polluted. 

Biomass, garbage burning, agricultural residue fires, forest fires are other agents that add to air pollution. 

As far as Kathmandu is concerned, air pollution varies depending upon the time of the day. 

Pollution level during early mornings and evenings in Kathmandu shoots up dramatically, while it decreased in the afternoons. Also, Kathmandu tends to choke on pollution during winter months. 

According to Shankar Prasad Poudel, senior divisional chemist at the Department of Environment, the government is monitoring 30 brick kilns of the Valley to analyse their contribution to air pollution in the Valley. 

The ongoing road-widening driving and Melamchi pipeline laying work to have been contributing to the Capial’s air pollution.