Dr Bhupendra Das, Air Quality Specialist.

He holds two master's degrees (Environmental Technology from the Teesside University, UK and Environmental Science from the Tribhuvan University, Nepal).

He completed his PhD program in Air Pollution/Emission Inventory.

Dr Das has more than 15 years of expertise at the local, national, and international levels.

He also serves as a part-time Kathmandu National Technical Expert at Clean Air Asia, Philippines.

He is also a chairperson at the Nepal Energy and Environment Development Services as well as a visiting faculty at Tribhuvan University.Dr Das has published over a dozen research articles in reputed journals, book chapters, and proceedings.

He received various awards, including the "Young Scientist Award" in the International Scientist Awards on Engineering, Science, -Medicine, held in Coimbatore, India, by the VDGOOD Professional Association.

In December 2023, Dr Das received the most prestigious Science and Technology Promotion Award from the Prime Minister of Nepal. Partially paralysed mother appeals for her son's release from the Russian army fighting in Ukraine Nepal's air quality improving Following a spike in air pollution in Kathmandu, Bal Krishna Sah of The Himalayan Times caught up with Dr Das about the problems caused by air pollution as well as its causes and remedies.

Excerpts:What is the current situation of air pollution in Kathmandu and Nepal? Air pollution is a serious issue in Kathmandu Valley and Nepal.

The Kathmandu Valley recently had the highest air pollution on record (i.e., first place globally), with PM2.5 exceeding the World Health Organization (WHO) standard (i.e., a daily average of 200 µg/m3).

Nepal was listed as the world's second most polluted country in terms of PM2.5 concentration (i.e., an annual average of 83.1 µg/m3) for the year 2019 by the Health Effects Institute (2020).

Furthermore, severe air pollution was also experienced in other parts of Nepal.

Nepal's government was forced to issue a national red alert/emergency declaration.

Schools were closed from March 30th to April 1st to raise awareness about public health issues.The biggest contributors to the rise in air pollution include the open burning of solid waste and biomass, as well as combustion technologies.

These sources generate not only known air pollutants (CO, NOx, SO2, NH3, and NMVOC), but also particulate matter (PM10, PM2.5, BC, and OC) and greenhouse gasses (CO2, CH4, and N2O).

The recent comprehensive studies that were carried out in Nepal include emissions from crop residue open burning, emissions from solid waste open burning, emissions from the transport sector, and other technology based sources.

All these sources point to an upward trend in yearly emissions.

Forest fires were detected in 3 lakhs in number from 2012-2021, it peaked in 2021.

The year 2024 has been observed at a critical time too, as forest fires have begun massively.Which regions of the country are most affected and why?Kathmandu Valley has been facing the world's most polluted city from March 2024 onwards, reaching a very unhealthy level (Air Quality Level gt; 250) and PM2.5 over 150 micrograms per cubic meter.Kathmandu Valley, along with Pokhara, Biratnagar, and Lumbini, are affected more.

The major sources that favor an increase in air pollution are the open burning sector, like solid waste open burning, especially in the Kathmandu Valley, and other cities like Pokhara, Birgunj and Biratnagar; crop residue open burning, especially in the Terai region; technology-based sectors like industrial and transport in the urban areas; fugitive emissions from cropland and livestock in the rural areas, and trans-boundary air pollution (from neighboring countries).What patterns have you observed? (Considering seasons, air pollutants, and sources, among other factors).The highest emissions of air pollutants occur during the winter (Nov-Feb.) and dry seasons (Mar-Apr).

The average concentration of PM2.5 is always 20 fold higher than the WHO annual guideline.

However, the lowest emissions are recorded during the pre-monsoon and monsoon seasons, which are closer to WHO daily guidelines.

Kathmandu Valley has a unique feature; for example, bowl shape topography, winter temperature inversion, more or less atmospheric stability with little winter rain (What have you observed about transboundary air pollution in Nepal?In Nepal, there is little information available on transboundary air pollution.

Nepal is a landlocked country that shares three sides with India and one with China.

Neighboring countries' development activities also have an impact on Nepal's air quality.

According to one report, trans-border air pollution is responsible for a significant portion of the haze in the country for the majority of this time.

Experts believe that winds blowing in from India's south and west are strong enough to transport harmful pollutants to many parts of the country, including the Kathmandu Valley.

Delhi and the cities of Uttar Pradesh are only 300 to 500 miles from Kathmandu by air.These cities are frequently ranked as the most polluted in the world.

Furthermore, crop residue open burning is more severe in Haryana, Punjab, and Uttar Pradesh, India.

According to the publication, open burning in these states contributes to Nepal's air pollution levels.

Likewise, air pollution from the Tibetan side must be thoroughly investigated.

The quantification of pollutants from transboundary air pollution in Nepal is in its early stages, and more research and development is needed.What steps are currently being taken to address these problems?After recognizing the need for improved air quality, the National Environmental Policy (2019), National Transport Policy (2001), Vehicles and Transport Management Act (1992), National Climate Change Policy (2019), Environmental Conservation Act (2019), National Ambient Air Quality Standard (2012), Nepal Vehicle Mass Emission Standard (2012), Air Quality Management Action Plan of Kathmandu Valley (2019), and Nationally Determined Contribution (2020) were developed.

In the year 2019, the Nepalese government changed the fuel tax, resulting in a threefold rise (i.e., NR 1.5 per liter) (Nepal Rajpatra, 2019).The second Nationally Determined Contribution (NDC) highlights the sales of electric vehicles (EV) to be 25% by 2025, which covers sales of private passenger vehicles and 2-wheelers.

It also emphasizes the deployment of 200 kilometers of electric rail network in the country by 2030 (NDC, 2020).

From April 2020 onwards, the government of Nepal enforced Euro-VI fuel quality with a low sulfur content.

Recently, the government of Nepal has finally decided to allow petrol and diesel vehicles to be converted into electric or other alternative fuel vehicles.

The discussion on emission standards is ongoing, and through this scheme, the government is planning to introduce vehicle grades higher than Euro III.

However, not much has been done to curb air pollution from open burning sectors.What are the most effective ways to reduce air pollution in Nepal and Kathmandu?Local farmers raising cattle for additional income could be a potential mitigation measure to minimize crop residue open burning.

The use of animal dung in residential biogas plants has the potential to reduce methane emissions while also meeting residential cooking energy demands.

The most important steps toward reducing emissions from open burning are the use of modified combine harvesters, reaper harvesters, and happy seeders, as well as alternative uses of chopped residue for animal feed, alternative energy production (e.g., bio-briquette), and raw materials for industries (e.g., brick kilns, paper production, mushroom cultivation, and so on).Improving waste collection services, waste segregation at the source, prohibiting MSW open burning, imposing a high penalty charge for open burning, establishing more Kawadi centers for waste recycling, air curtain incineration practices, systematic waste disposal, and raising awareness are the most important steps to reduce pollution and its effects from municipal solid waste open combustion.The best possible mitigation options for the transportation sector include revising the 2001 Transport Policy, implementing interventions like vehicle inspection and maintenance, road repair and maintenance, better fuel quality (since lower-grade fuel quality increases emissions and EFs), vehicle labeling (e.g., orange, yellow, green), prohibiting high-emitting vehicles in urban areas, and enhancing sustainable low-carbon transport pathways (e.g., gt; BS III/Euro III vehicles, hybrid vehicles, better fuel with low sulfur and lead content, clean -renewable energy fuel like hydrogen fuel, solar energy, government subsidies, tax exemptions, and scrappage of high-emitting vehicles, and research-based vehicle emission standard).For the time being, the immediate actions include the use of bio-briquettes as an alternative fuel source for brick kiln industries, the deployment of electrical induction stoves for household cooking stoves, the use of firefighting helicopters to extinguish open burning, and the sprinkler of water in urban areas.

Wearing masks, particularly outdoors, helps to reduce the impact of air pollution.A number of urgent measures are required to reduce forest fires and the air pollution they cause, including the use of firefighting helicopters, at least in each province; fireproof clothing; artificial ponds surrounding the forest; mapping forest fire hotspots; monitoring, inspecting, and charting forest fires; and increasing local awareness. .

This article first appeared/also appeared in https://thehimalayantimes.com