Things are up in the air in Nepal


Everyone in Kathmandu knows we breathe some of the dirtiest air in the world. As if we needed any more proof, a new study uses technology developed during the Cold War to analyse radioactive particles to pinpoint where the pollution is coming from.

In the first week of November in 2020, the concentration of PM2.5 in Kathmandu’s air doubled in a matter of a few days. A Nepali Times pollution monitoring project measured an Air Quality Index (AQI) as bad as 430 at its peak.

Satellite images showed blue smoke from Pakistan and India’s Punjab and Haryana blanketing the Indo-Gangetic plains and Nepal’s Tarai and moving up the Himalayan valleys. Farmers were burning post-harvest biomass, and the link between the two was obvious.

Now, international researchers have used a technology originally developed by the US military to locate Soviet atomic tests by analysing tiny particles in the air blown across the Pacific by prevailing winds.

The model is now used widely for real-time wildfire smoke detection and forecasting, and to study stationary sources of anthropogenic emissions of greenhouse gases.

Satellite-based sensors showed that the smoke was from more than 3,000 active fires in Punjab and Haryana, its plume transported by prevailing winds to the foothills of the Himalaya and up to Kathmandu Valley.

“It was not just the open burning in Haryana and Punjab but also weather conditions that allowed for aerosols concentrated in the southern plains to be transported to Kathmandu and higher elevations,” says climate scientist Binod Pokharel, one of the authors of the recent paper in the journal Atmospheric Pollution Research.

The team consisting mainly of Nepali scientists deployed the tongue-twistingly named Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT), a computer model that computes air parcel trajectories to determine how far and in what direction pollutants will travel.

“Our main objective was to start a multilateral dialogue between countries in the region because while local solutions are important, air pollution is also a transboundary problem and needs committed leaders working together to develop and implement policies prioritising air pollution and mitigate its impact on public health,” adds Pokharel, who is Associate Professor at Tribhuvan University in Kathmandu.

Lack of real-time data at ground level and different elevations due to a limited number of functioning air monitoring stations has been a major hurdle for scientists who have had to rely only on modelling. For example, air pollution in Kathmandu peaked again in March 2021 reaching AQI over 600 after unprecedented wildfires raged across Nepal following winter drought.

Another recently-published research confirmed that vehicular emissions are a major source of air pollution in Kathmandu Valley, and old buses and poorly maintained vehicles make it worse.

Researchers conducted composite measurements of particulate matter, carbon monoxide, sulphur, nitrogen dioxide and ozone and built a comprehensive diesel vehicle emission inventory of Nepal from 1989 to 2018.

Published in the journal Science of the Total Environment the researchers found diesel consumption in Nepal increased 13-fold during the study period, and concluded that fuel quality and poor engine maintenance were the main culprits for pollution.

“We found that regular servicing and maintenance of vehicles can reduce pollution by up to 60% and this figure is even higher at 90% for petrol-run automobiles,” says Bhupendra Das, lead author and researcher at the Institute for Advanced Sustainability Studies in Potsdam, Germany.

“But the real solution lies in finding the political will to replace fossil fuel vehicles with electric ones, and introducing Euro 6 vehicles, most of all we need to revise and update our transport policies,” says Das, who is also associated with Tribhuvan University.

All this is not just bad news for public health and the global climate, but the soot particles called ‘black carbon’ are also carried up to the mountains where they are deposited on the ice and snow, making them absorb more sunlight and melt faster.

Nepal has pledged that at least 25% of all private passenger car sales and 20% of public transport vehicles will be battery-powered by 2025, but government policy does not reflect this. Presently, while private electric SUVs get a tax rebate, it is diesel buses that are subsidised, while electric ones cost five times more because of high customs duty and other taxes.

Both India and China have committed to only manufacturing battery-operated vehicles from 2030. The world has now moved on to the possibility of zero-emission with hydrogen fuel, but Nepal’s policies do not reflect its Glasgow goals.

As a result, air pollution in Nepal’s cities is getting worse and is a leading cause of asthma, high blood pressure, lung inflammation, congenital disabilities, mental disorders, various cancers and allergic hypersensitivity. Air pollution was the direct cause of 42,100 deaths across the country in 2019, and is reducing the average lifespan of people by at least four years.

A United Nations report this week stated that pollution and toxic substances cause 9 million premature deaths annually, much more than the Covid-19 pandemic that has claimed 5.8 million lives in the last two years.

‘Current approaches to managing the risks posed by pollution and toxic substances are clearly failing, resulting in widespread violations of the right to a clean, healthy and sustainable environment,’ states the report to be presented at a forthcoming meeting of the UN Human Rights Council.

Worldwide and in Nepal, state priorities in favour of revenue and industry over the health of citizens is the main reason for worsening pollution. Only urgent policy level interventions can set things right, and for that there needs to be public pressure on candidates for local and national governments during this year’s elections in Nepal.

survey in this paper ahead of the 2017 elections showed ‘air pollution’ topping the list of concerns of Kathmandu citizens — even ahead of water supply, health, education and inflation (see graph above). Air pollution in Kathmandu has gotten much worse since then.

Says researcher Bhupendra Das: “Air pollution is no more a mere environmental and health crisis, it is a political issue and must be treated as such.”

Sonia Awale


Sonia Awale is Executive Editor of Nepali Times where she also serves as the health, science and environment correspondent. She has extensively covered the climate crisis, disaster preparedness, development and public health -- looking at their political and economic interlinkages. Sonia is a graduate of public health, and has a master’s degree in journalism from the University of Hong Kong.