The Global Urbanist

News and analysis of cities around the world

Air pollution in Ulaanbaatar: the haze that hides the eternal blue sky

With one of the highest levels of air pollution of any city in the world, the Mongolian capital is learning how to reduce its levels of particulate matter and replacing tens of thousands of traditional heating stoves with cleaner alternatives.

Cameron Wright and Justine Smith

Cameron Wright and Justine Smith

Cities: Ulaanbaatar

Topics: Health and aging, Internal migration, Environmental impacts, Pollution

Mongolia is known as "Munkh Khukh Tengeriin Oron" or in English, "the land of the eternal blue sky". Some time spent in the countryside will make it obvious why. However, during winter in the capital Ulaanbaatar, air pollution creates a barrier between residents and this wide blue sky.

The city's annual average level of fine particulate matter (PM 2.5 — particles with an aerodynamic diameter of less than 2.5 microns) is the highest in the world, based on a World Health Organisation (WHO) dataset of 576 cities from 38 countries. The corresponding levels of respirable suspended particles (PM 10 — particles with an aerodynamic diameter of less than 10 microns) are second only to Awhaz, Iran, amongst 1,099 cities from 91 countries. Fine particulate matter can penetrate deep into the lungs and has been shown to contribute to adverse health outcomes, particularly conditions related to the cardiovascular and respiratory systems.

Average levels of PM 2.5 in Ulaanbaatar regularly exceed 300 micrograms per cubic metre over 24-hour periods during winter. On 15 December 2013 the 24-hour average for PM 2.5 was 376 micrograms per cubic metre. There is marked variation over the course of the day. From 12 noon to 3pm the average level was 147 micrograms per cubic metre, while from 6pm to 9pm this had increased to average 696 micrograms per cubic metre.

To draw a comparison, on 21 October 2013, when bushfires burned on the outskirts of Sydney, average PM 2.5 counts reached unusually high levels for that city of between 149 and 295 micrograms per cubic metre over 24 hours. This is well above the 24-hour PM 2.5 air quality guideline of 25 micrograms per cubic metre set by the WHO and is enough to trigger concerns over health implications, particularly for the elderly and those with heart and lung conditions.

Living in Ulaanbaatar, we have witnessed the change in pollution levels as summer gives way to winter. As the temperature dropped, we noticed decreased visibility, a burnt smell in the air and on our clothes, and irritation in our throats.

Why is Ulaanbaatar so polluted?

There has been unprecedented rural-to-urban migration in Mongolia over the past two decades. 44% of Mongolia's 2.9 million people now call Ulaanbaatar home. More than half of the city's population lives in the "ger areas" that lie around the city's periphery. These areas are not connected to reliable sources of electricity (in some parts), running water or adequate sewerage. To keep warm during winter, when temperatures can drop below -40C (-40F), residents burn coal and other fuel sources in stoves inside their gers (traditional Mongolian houses). At one monitoring site, emissions from stoves accounted for 87% of total PM 2.5 production.

The topography of the city further exacerbates the problem. Ulaanbaatar is situated in a valley, with mountains to the north and south. This hinders dispersion of the pollution away from the city. In addition, frequent temperature inversions occur whereby cold air near the ground is trapped by warmer air above, sometimes for several days, keeping the pollution trapped.

Establishing the link with public health

Delgerzul Lodoysamba is a Mongolian researcher working to better characterise the health effects of air pollution in Ulaanbaatar. She used 2008 air quality data to assess the correlation between PM 2.5 and PM 10 levels and the number of visits to a health centre for respiratory-related symptoms in one of Ulaanbaatar's most polluted subdistricts. The results of this study, which were presented at the 2013 International Society for Environmental Epidemiology conference, showed that during winter increased air pollution levels correlated with increases in clinic presentations for respiratory problems.

The association between public health and air pollution is complicated and is a relatively new field of study in Ulaanbaatar. According to Delgerzul, research so far has primarily focused on quantifying air quality from an environmental perspective, rather than in terms of short- and long-term health impacts.

While air pollution levels remain high, Delgerzul suggested that reducing exposure to outside air during winter is the best way to reduce the risk of adverse health effects. However this strategy is not always practical. For those who must spend time outside when it is highly polluted, some masks are able to filter out at least some particulate matter. Even so, the cost of these is beyond the reach of many Mongolians, with 27% of the population estimated to be living below the poverty line.

What is being done to improve the situation?

Lodoysamba Sereeter and Crispin Pemberton-Pigott advise the national stove-testing laboratory, which tests different stove designs for efficiency and production of particulate matter and other chemical emissions. They also regularly monitor pollution levels in Ulaanbaatar.

One initiative to reduce pollution in Ulaanbaatar is to replace traditional ger stoves with models that emit 70% to 90% less particulate matter. Given the large proportion of particulate-matter pollution generated by stove use, this is a strategy with great potential. So far over 120,000 ger stoves (of an estimated 175,000 in Ulaanbaatar) have been replaced. The majority of these were co-subsidised by the Mongolian government and a grant from the Millennium Challenge Corporation between 2010 and 2012. The out-of-pocket cost for these stoves ranged between $14 and $30 depending on the size, and an educational campaign was run concurrently to drive demand. 45,000 stoves have been government-subsidised as part of the Ulaanbaatar Clean Air Project, supported through a World Bank loan.

These stoves are most effective at reducing pollution when used correctly, such as when lit properly and refueled at the correct time using an appropriate fuel source. Education of the public by vendors is an important aspect of this intervention.

Other pollution reduction strategies include better insulation for gers and a low interest loan scheme to encourage those living in gers to move into centrally heated apartments.

Looking to the future

All of the experts we spoke to agree that a major challenge in this area is ensuring evidence-based solutions are implemented and carefully evaluated for effectiveness. Delgerzul Lodoysamba suggested that involving air pollution scientists, business and strategy professionals and representatives from the most pollution-affected areas at the policy level would help to improve the situation. There is a National Committee on Reducing Air Pollution currently operating in Mongolia. Diversifying its membership to include greater representation from members outside of government may help it in its work to guide a coordinated and evidence-based strategy to combat air pollution.

Air quality science in Mongolia is a growing area. Talking to these three experts, it quickly becomes evident that this is an area ripe for future research and they have a palpable ethusiasm to build a stronger evidence base to guide policy and action. Assistance from international experts also has the potential to make a major contribution and already many scientists from abroad have collaborated with their Mongolian counterparts. US-based atmospheric scientist Christa Hasenkopf, who spent two years working in Ulaanbaatar, noted that the city is an ideal laboratory to test the efficacy of strategies to reduce air pollution. This is because the city is not surrounded by other urban centres that could complicate pollution measurements.

Increased public awareness, particularly through media advocacy, is also an essential aspect of improving the situation in Ulaanbaatar. Lodoysamba Sereeter uses Facebook and Twitter to disseminate air quality data generated through his laboratory to provide the public with unbiased information. It is important that media coverage avoids simple critique of people living in gers trying to stay warm during winter and acknowledges that air pollution is a complex issue with multiple social and environmental determinants. Increased public awareness will drive further advances and a greater demand for high-quality, long-term solutions.

Cameron Wright and Justine Smith The authors wish to thank the following experts interviewed for this article: Professor Lodoysamba Sereeter, nuclear physicist and team leader of the Air Pollution Unit at the National University of Mongolia; Delgerzul Lodoysamba, PhD candidate and part-time lecturer at the Department of Environmental and Occupational Health, Health Sciences University of Mongolia; and Crispin Pemberton-Pigott, senior technical advisor to several World-Bank-supported clean stove initiatives in Asia and senior technical consultant, SeTAR centre at the University of Johannesburg. Thanks also to Martine Dennekamp, occupational and environmental epidemiologist working in the field of air pollution, health and the environment at Monash University, Melbourne, for her comments and review of this article.