“We could’ve been killed in that flight. The air pollution in Kathmandu has gotten so bad that if people don’t act now, we’re putting lives in danger here,” Kevin A. Rushing, the former USAID Mission Director to Nepal, commented in a recent conference.[break]
“Just when our plane was about to land in Kathmandu, due to thick smog over the Valley, we couldn’t see the runway, we couldn’t see anything.
The plane then had to divert all the way around, reroute and keep flying in such a condition despite the turbulence risking the lives of all people on board.” He added, “If things don’t improve, you’d really think twice about flying to Kathmandu.”
Captain Vijay Lama, a pilot with Nepal Airlines who has been flying for more than two decades, says that Rushing’s anxiety is valid.
“The flying conditions in Kathmandu have become terrible, especially during winter”, he says. “In winter, when fog combines with smoke and other pollutants in the air, the resulting smog worsens the visibility, and it’s far worse than when it’s foggy.”
According to Lama, the rising pollution can have drastic effects on visibility on both land and in air. “There’s an increase in the number of flights being backlogged, and there are always delays after delays.
It’s all because of the smog and haze condition,” he says. “As the smog is heavier, it settles in lower altitude, and with the amount of smoke and dust particles that adds on with the moisture in the air, it becomes denser, making it impossible to fly.”
Whereas smog is mostly formed in the winter due to the mixture of smoke and fog, haze often occurs in pre-monsoon seasons that have relatively dry air, combining with the smoke and dust or particulate matters or total suspended particles (TSPs) in the air.
The chemicals which contribute to formation of smog also include harmful man-made and naturally occurring compounds, such as sulfur dioxide, carbon dioxide, carbon monoxide, nitrogen oxide, and ozone.
As reported by the US Environmental Protection Agency (EPA), when these components of smog mix up, they can create dust clouds, black soot and gray fog. This can result in a smog cloud that can reduce visibility by 70 percent.
Captain Lama stresses that if the situation in the Kathmandu Valley isn’t addressed soon, the flying conditions will just get worse, and with the risks involved, the future of aviation in Nepal could be very bleak.
According to the 2006 report “Urban Air Quality Management Strategy in Kathmandu Valley” by Jitendra J. Shah and Tanvi Nagpal, atmospheric visibility data from Kathmandu’s airport, analyzed onwards from 1970, show that there’s been a very substantial decrease in the visibility in the Valley since about 1980.
The number of days with good visibility around noon has decreased in the winter months from more than 25 days per month in the 1970s to about five days per month in 1992/93.
“Visibility is the measure of the distance at which an object or light can be clearly distinguished or seen. In aviation, it can differ with the aircraft type,” says Mishri Lal Mandal, Deputy Director of Air Traffic Services (ATS) Division of Tribhuvan International Airport Civil Aviation Office (TIACAO).
Basically, for Visual Flight Rules (VFR) or visually aided flights, the minimum visibility to be maintained is 5km.
This means the pilot has to be able to clearly distinguish an object as far as five kilometers away with his eyes whereas for Instrument Flight Rules (IFR) or instrument aided flights, pilots can fly even with the visibility is 800 meters while taking off and 1,600m for landing, he informs.
As helicopters in Nepal only operate with VFR, it’s more risky for helicopter pilots, according to Captain Nischal KC, helicopter pilot at Air Dynasty.
“When there’s haze or smog, it gets very difficult for pilots not just in terms of visibility but they also get disoriented and nauseous at times,” says KC “As helicopter pilots don’t have an instrument landing aid, we have to fly by considering the artificial horizon, and a lot of experience is required.”
KC adds that it’s the reason why during pre-monsoons and winters, when haze and smog problems are at its peak, new pilots aren’t allowed to fly without experienced co-pilots.
Ratish Chandra Lal Suman, General Manager of TIACAO, says, “Instrument flights for the Kathmandu Valley are more complicated with its hilly terrains. (So) We’re planning to bring Required Navigation Performance Authorization Required (RNPAR) technology that can help flights operate even in poor visibility as it operates through satellite signals and follows a specific path and reduces pilot workload.”
Suman shares that the increasing trends in poor visibility conditions result in flights being diverted or stranded. Then, as soon as the conditions become favorable, flights start piling up, and there’s more load than the capacity of the terminal building.
“Safety is our first concern. So we don’t authorize any flight to operate in poor visibility,” says Suman. “Besides that, we also lose out on a lot of revenue when flights have to be cancelled, diverted or rerouted due to poor visibility.”
KC, however, points out that flights and helicopters are also given the go ahead if there’s a visibility of more than 1,000m. From then on, it’s the pilot’s decision whether to fly or not.
In the article “Are Nepali Skies Safe?” by Amish Raj Mulmi and published in The Kathmandu Post in August 2010, Lama also mentioned that there is pressure for pilots to fly no matter what the weather condition or visibility is like. And the pressure came from everywhere—political leaders getting late for a meeting, to airline operators losing out on revenues.
According to Pramod Nepal, Air Traffic Control Officer at Ministry of Tourism and Civil Aviation, though poor visibility isn’t specifically pointed out in aircraft accident investigation reports, it could be one of the obvious reasons in crashes.
“Most investigations in aircraft accidents in Nepal mention Controlled Flight into Terrain (CFIT) as the cause which is a state of flight when the pilots have full control of the flight and yet the plane hits terrain,” explains Nepal. “The poor visibility problem obviously can be generalized as one of the reasons of CFIT, but mainly, the investigations focus on the technical and human error aspects.”
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Mani Ratna Shakya, Chief of Meteorological Forecasting Division, says that the fog in Kathmandu has actually decreased to quite an extent due to a rise in temperature at the ground level as a result of more energy consumption, industrial and vehicular emissions with growing population and urbanization.
This should result in clearer visibility in the winter.
However, on one hand, though fog gets dissipated quite easily due to the growing air pollution, thick smog has replaced it, making the situation even worse.
Bidya Banmali Pradhan, Environment Officer at the International Centre for Integrated Mountain Development (ICIMOD),says that the major factors that diminish air quality in the Valley are vehicular emissions and exhaust fumes from the brick kilns.
Besides that, construction works and soil erosion due to unpaved roads also contribute to air pollution.
An inventory of emission sources by the then Ministry of Population and Environment (MoPE) indicated that exhaust fumes had increased more than four times in the eight years between 1993 and 2001.
According to a more recent inventory, vehicular emissions are responsible for 38% of the total PM10 or particulate matter emitted in Kathmandu Valley, compared to 18% from the agricultural sector, and 11% from brick kilns.
The average PM10 count concentration in Kathmandu was 183ug/m3 in 2003 and 173ug/m3 in 2007, both far above the National Ambient Air Quality Standard of 100ug/m3, and World Health Organization’s standard of 50ug/m3.
“The Valley is vulnerable to air pollution due also to its bowl-shaped topography that restricts airflow due to which pollutants and smoke isn’t dispersed properly,” says Pradhan.
The effect is worse in winter, she elaborates. In summer, the air is warmer; so it rises upwards along with gaseous pollutants, and has higher chances of dispersion. But in winter, because of the inversion effect, the cold air is trapped under a layer of warmer air to create a lid, thus trapping the pollutants within the Valley’s atmosphere.
Pradhan and Environmental Chemist at Nepal Environmental and Scientific Services (NESS) Sunil Babu Khatry agree that the mitigation measures for smog and haze would be to focus on the major sources of emissions and TSP in the Valley.
“The vehicular population has to be brought under control, and even if we could manage the solid waste on the road with good pedestrian habits, air pollution could go down to a good extent,” says Khatry.
“The roads must be kept clean and in proper condition so that there’s less flying dust. Taking legal measures to control both vehicular and industrial emissions would also be good, but for that, the implementation by the governing authorities has to be made strong.”
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Unfortunately, there’s not much or no implementation of any project policy for air pollution control being carried out by the government at the moment.
Rabin Man Shrestha, Chief of Environment Management Division of Kathmandu Metropolitan City (KMC) says that besides tree plantation, waste management and awareness campaigns, KMC doesn’t have any current project for air pollution control.
Most government officials only refer to the now defunct air quality monitoring project as the step that was taken to manage air pollution.
“The government, with Danish support, had initiated Air Quality Management of Katmandu Valley in 2001 with six monitoring stations placed in different parts of the Valley.
The government was supposed to take over after the support was discontinued in 2009, but it couldn’t due to financial and institutional problems,” informs Rishi Raj Koirala, head of the Environmental Standard Section at Ministry of Environment (MoENV).
However, Joint Secretary of MoENV Meena Khanal says that the six monitoring stations that went out of operation due to load shedding have been repaired, and the Ministry has prepared a tender to get the stations into operation again.
“Besides, the Ministry also has set standards for emission control to minimize air pollution,” says Khanal.
“There are rules, such as issuance of green stickers and ban on old vehicles, but the environment ministry alone can’t work on monitoring and implementation of such rules. Transportation management and industrial emission control has to be carried out by other Ministries concerned as well.”
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Captain Lama, one of the most experienced pilots in Nepal, terms the flying condition during the hazy days in the Valley as “dreadful.” And yet, the wait for the monitoring machines to operate, or standards to be met, or rules to be followed, and a proper budget to be passed for cleaner air and clearer skies is still not likely to end.
As air pollution in Kathmandu worsens and its skies become obscure with layers of haze and smog looming in its atmosphere, nothing is being done to assure the safety of the thousands of passengers flying in and out of there everyday. Civil aviation remains at risk, and if these conditions remain unchanged, it can only get worse.
Health impacts, Dr Arjun Karki, Chest Specialist at Patan Hospital, says that the primary effects due to smog or haze would obviously be on respiratory health.
“Lung diseases can become chronic, proportionate to the concentration and density of smog,” he says. “And if the gases present in the smog comprise specific toxins, the harm could be even greater.”
According to Karki, on one hand, smog and haze can aggravate the health of people who already have respiratory problems, like asthma, it can also trigger lung disease in healthy people as well.
“Besides, it also depends on the length of exposure,” he says. “Besides respiratory health problems, it can also cause eye irritation for some people.”
However, Dr Mukunda Prasad Kafle, physician and Lecturer at the Teaching Hospital, says that while the unhealthy effects of smog or haze in particular can be many, not enough studies in this regard have been conducted here.
“As smog and haze come under air pollution, we can deduce that the health problems are similar to the ones caused by air pollution, like lung diseases and other respiratory problems. And smog can have its own adverse effects as well.”
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