Kathmandu valley residents endured dangerously high air pollution levels this week, with new data revealing that 75 out of the past 90 days had unhealthy or hazardous air quality.
Experts from International Centre for Integrated Mountain Development (ICIMOD) have pointed towards rampant pre-monsoon forest fires, worsened by drought conditions, as the primary cause.
On April 3, Nepal’s Air Quality Monitoring dashboard recorded alarming Air Quality Index (AQI) readings: 365 in Bhaktapur, 273 in Shankhapark, 248 in Ratnapark, and 235 in both Bhaisepati and Khumaltar — far exceeding safe limits.
Sagar Adhikari, an air pollution analyst at the ICIMOD, linked the spike to widespread forest fires, particularly in Nepal’s drought-stricken western regions.
"Dry conditions have fueled more fires, compounding pollution from vehicles, construction, and household emissions," he said.
"Current weather patterns are trapping toxic air over the valley," Adhikari added.
The fires release deadly pollutants, including fine particulate matter (PM2.5), carbon monoxide, and black carbon — a known health hazard that can enter the bloodstream, triggering respiratory diseases and premature deaths.
While exact mortality figures from this year’s fires remain unknown, Naryan Babu Dhital, an assistant professor at Tribhuvan University, warned of long-term risks. "In 2019, ambient PM2.5 pollution caused 48,000 deaths in Nepal," he said, citing Global Burden of Disease data.
"We urgently need primary research to assess the current crisis."
The fires also emit black carbon, a potent climate-warming agent that accelerates glacial melt and disrupts monsoons.
Khushboo Sharma, another ICIMOD analyst, noted, "Up to 39% of glacial melt in the Hindu Kush Himalaya is tied to black carbon. Cutting these emissions demands regional cooperation to safeguard both glaciers and public health."
Nepal’s Department of Environment has expanded air quality monitoring to identify pollution hotspots. However, experts stress that without faster emission cuts and better fire management — such as early warning systems and sustainable land practices — the crisis will persist.
As Kathmandu struggles for breath, the need for urgent local and global measures grows clearer. Without intervention, residents face escalating health risks and environmental damage in the years ahead.