NEC study shows deteriorating air quality in Bhutan

Bhutan’s air quality may not be as pristine as you would think according to a study by the National Environment Commission (NEC).

Data with the NEC shows that the air quality in Bhutan is getting worse by the year across the country and more so in urban areas like Thimphu.

The NEC since 2004 had initiated the monitoring of particulate matter of a diameter less than 10 micro grams (PM10) in Thimphu and later in other stations like Kanglung,

Rinchending, Gomtu and Pasakha representing a mix of all places.

‘PM10 or more popularly known as ‘dust’ is the most common parameter being monitored as it is something that people can breathe in.

Thimphu and Kanglung fall under the sensitive area given the high number of residents staying in these places. Gomtu and Rinchending fall in the mixed area as it has both residential and commercial areas and Pasakha falls under industrial area.

A 2013 NEC report titled ‘Air Quality Status Over 2011-2012’ suggests that there is higher PM10 level during winter and it gradually declines to the lowest level during summer. PM10 level is highest during the month of March, which is also a windy month of the year.

“Compared to 2011, the overall data says that the average PM10 in 2012 is significantly higher which includes increased percentage of days that exceeded both national standards and recommended WHO guidelines,” states the report.

The report says, “Although the annual average levels are within the national limits, the levels are higher than WHO guidelines.” It further reads, “There is an increasing trend in annual levels of PM10, meaning that while the air quality level remains within national standards, the air quality in Bhutan is steadily deteriorating especially in Thimphu and around industrial areas.”

The report has some bad news of Thimphu as it shows a virtual doubling of air pollution from 2007 to 2012.

“For Thimphu the trend of PM10 level is increasing year after year. By 2012, the average PM10 level has doubled from 2007,” says the report. However it also says that “the main caveat of this analysis, of course, is the data points (points where air pollution data is collected) and none of the stations are continuously monitored throughout the year.”

The overall national air pollution level from all the stations was recorded higher in 2012 compared to 2011.

“From 2011-2012, it was observed that percentage of monitoring days that exceeded national permissible limits (air quality) at respective stations has increased significantly,” said the report.

In the case of Pasakha it increased to 41% in 2012 from 2% in the year before. For the Pasakha stations, all the data points in 2012 are above WHO recommended guidelines.

The pollution level is higher during the dry season and lower during wet season across all stations indicating how light rainfall during the wet season helps in decreasing PM10 level. The variation of PM10 is more distinct at Pasakha corresponding to the dry and wet seasons in a year.

2007 is adopted as the base year. It suggests that except for 2008, the percentage increase in pollution level for other years are statistically significant from 2007. The pollution level has doubled in 2011 and 2012, states the report.

“When we see the report, the trend we see is that it is sort of getting worse but it’s still within the limit NEC Climate Change Division’s Chief Thinley Namgyel said.

“What is more harmful in terms of air quality is not really PM10 that you can almost breathe in and back out and cough it out but it is PM2.5 which is much smaller which gets lodged in lungs that is more harmful,” he added.

“So now we have proposed and got some budget to start monitoring PM2.5 in the heavily populated areas like Thimphu and Phuentsholing,” he said.

He said that were still some unknowns that needed to be monitored. He gave the example of the unknown impact of forest fires on the quality of air.

Thinley said that the air pollution in Pasakha was a more complicated issue. “In winter there is an ‘atmospheric brown cloud’, which is not only limited to Pasakha, but also the southern border areas and districts which we are concerned about because it is a trans-boundary haze and have various factors contributing to it. It is difficult to say where it is coming from and that’s what we are trying to see,” he said.

He said that a station coming up soon to try and measure all those different components.


In the meantime the NEC said that several measures are being taken by them. The NEC set the national air quality standards and also standards for emission from factories or cars, where one has to meet certain limit. He said that in terms of factories one has to install pollution control devices, and it is a part of environmental clearance to minimize emissions.

Thinley said they go for random checks to make sure that the factories are within those limits and in compliance.

He explained that, the vehicle emission testing standard has been revised twice for the reason that when it first started, it was understood that people didn’t know how to take look after vehicles in terms of emissions, the workshops were new and fuel quality was not good then. After the standard was set up, the government had negotiated for improved fuel quality from India and so since the technologies were improving, the emissions are also supposed to be better, he said.

“The emission standard is supposed to become stricter and stricter and in next couple of years we can expect the emissions standards to be more stringent for cars,” Thinley said.

Different initiatives have also being taken in collaboration with the Department of Energy, Department

of Forests and Bhutan Trust Fund in promoting cleaner and electric stoves in institutions where they burn a lot of firewood.


Lack of adequate data, the need to increase the parameters of monitoring for network stations, limited manpower and logistical problems in installing air quality monitoring equipment are some of the challenges being faced in monitoring air quality in the country.

Just now one of the challenges he said was construction dust especially in the local areas and the increasing number of vehicles, throwing up a challenge of how to actually ensure that the emissions are actually within limits.

Air quality status says different locations represent different geographical areas and the area with different level of anthropogenic activities.

Internationally air pollution is the world’s largest single environment health risk with the World Health Organization (WHO) report showing deaths of 7mn people in 2012 which accounts for one eight of total global deaths.

Thinley Namgyel said it is not as big a concern in Bhutan right now but could be one in the future.

“WHO, looks for both indoor and outdoor pollution and in Bhutan case when it comes to indoor pollution health and concerned agencies are already taking care of it like promoting improved stoves because indoor air pollution has a direct impact on health in Bhutan. So far nobody has done the study on which is more harmful, we don’t know that, so we can’t say,” he added.

Thinley said that air pollution reduces life spans and even affects infants from an early age affecting their respiratory organs. “For now we haven’t been able to figure out how much impact it has on health.” He said. “We have plan by next year to study the health impacts,” he added.

He explained saying there are other factors other than air pollution for which we Bhutan needs data, like for instance, respiratory diseases.

Some of the sources of air pollution in the country are from exhaust emissions from diesel and petrol vehicles, particulate matter from brake and tire ware, industrial emissions, smoke from wood stoves (i.e. cooking and space heating), wind-blown dust from unpaved roads and constructions/ mining activities, smoke from open burning and road side construction and trans-boundary air pollution sources.

Tashi Deki / Thimphu


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