ULAN BATOR (Reuters) - Inside a stove showroom deep in the suburbs of this sprawling smoke-filled city, Mam Ivermint, 80, is shopping for a new coal-fired stove -- her unlikely contribution to the cause of cleaner air.
The cast-iron stove she selects is low tech, but very different from the traditional Mongolian heaters responsible for spewing much of the grit that fills Ulan Bator's skies, making it the world's second-most polluted city. It includes features that cut smoke emissions by 80 percent.
"I am happy to replace my old stove," said Ivermint, a retired accountant. "This new stove burns much cleaner and is more fuel efficient. It will make our city a cleaner place to live."
The plan to swap old stoves for cleaner models is part of a new effort by the government and donor organizations to reduce air pollution in one of the world's smoggiest cities. The World Health Organization places Ahvaz in southern Iran in the top, most-polluted spot.
Many residents live in gers, drafty felt tents that Mongolian nomads have used for centuries. Tens of thousands of nomads have moved to Ulan Bator in recent years in search of work, bringing coal-fired cast iron stoves to keep warm in temperatures that fall to minus 30 Celsius (minus 22 Fahrenheit) in winter.
The resulting soot that envelopes the city -- particularly during the winter -- has created a health crises, say experts. A recent report by Simon Fraser University in Vancouver stays that one in 10 deaths in Ulan Bator is associated with air pollution.
Conditions in the capital contrast sharply with the rest of Mongolia, a vast and mostly empty country with plains, mountains and blue skies.
Ulan Bator's air also underscores the increasing contribution of developing world to global warming. Developing nations now emit more than half of mankind's greenhouse gas pollution, fueled by soaring demand for coal, oil and gas to power their booming economies.
"The pollution problem becomes apparent to anyone who lands at the airport in winter. you can see it on approach, it's a very dark brown smog over the city," said Courtney Engelke, a representative of the Millennium Challenge Corporation (MCC), a US-funded donor organization working to clean up Ulan Bator's blackened skies.
"I have been to ger districts in the height of winter," she added. "I found it close to unbearable. I felt a shortness of breath. Almost a choking sensation."
When Mam Ivermint installs the new heater, her old family stove will not merely be tossed aside. It will be destroyed to prevent others from using it.
The plan to swap old stoves for cleaner models is a part of a joint project by the government and the MCC to sell the stoves at subsidized rates.
The original price of the stoves is 325,000 tugrik ($260), but after a subsidies from the MCC and the government, the cost to the buyer falls to 25,000 tugrik ($20).
That compares with US$25 to $40 for a traditional stove.
Using a unique air flow pattern, the stove allows coal to burn longer than a traditional stove, requiring one third the amount of coal. Most of the coal's particulates are burned up inside the stove, eliminating four-fifths of the exhaust that exits through the stove pipe.
The stoves have been wildly successful so far, with more than 15,000 units sold in less than three months. The MCC hopes to sell an additional 80,000 during the final two years of the project.
Besides the low smoke stoves, other options developed by the MCC include heat efficient felt coverings that wrap around the ger and a vestibule fitted around the door. The program also includes tree planting in ger districts, which for the most part are sprawling patches of waste ground.
The MCC is putting US $50 million into the project with additional commitments made by the government.
The WHO survey on air quality looked at the density of airborne particles less than 10 micrometers, also called PM10 concentrations. The annual average PM10 concentration in Ahvaz was 372 micrograms per cubic meter while Ulan Bator was runner up with 279. Washington DC had just 18.
Ulan Bator's pollution is seasonal, with relatively low amounts in summer, but critical levels in the depths of winter when the PM10s can reach 2000 micrograms per cubic meter in the worst affected areas.
The 10 most polluted cities on the planet are all in emerging market or developing countries: Iran, Pakistan, India, Botswana and Mongolia. Chronic polluter China no longer has any cities in the top 10.
Most of the PM10s are produced in sprawling slum-like "ger districts," where in winter most of the 150,000 families living in these areas burn two or three small bags of raw coal a day.
Burning raw coal emits mercury, nitrous oxide, sulfur dioxide, and fine particulate matter (PM), as well as carbon dioxide, a greenhouse gas that contributes to global warming.
"The poorest of poor burn other things, like garbage and tires, which creates a toxic brew of its own," said Engelke.
The city's three Soviet-era coal-fired power stations -- Mongolia was once a satellite state of the Soviet Union -- and its 180,000 cars are other contributing factors.
Ulan Bator's population, 1.2 million, has doubled over the past decade. Yet, despite the crowded conditions in the capital, Mongolia is the world's least densely populated country, three times the size of France but with a total population of just three million.
Atmospheric scientist Christa Hasenkopf, says breathing the city air over the course of 12 months would be equivalent to living in a home with somebody who smoked 60 cigarettes a day.
"It's a rough calculation, but by any measure the air quality in winter is deadly," says Hasenkopf. "The particulates are a main source of respiratory disease because they are so small and can reach deep into the respiratory system."
For the government, the long-term solution is to convert the ger areas to more permanent housing, with apartments that can be connected to the central heating grid. But years, perhaps decades, are needed to build the infrastructure required to house a half million people.
The government has also proposed banning the use of raw coal in districts close to the city center, but enforcement of such a ban could be difficult in hard to reach, overcrowded areas.
The retired accountant Ivermint, a new crusader in the fight against air pollution, hopes the success of the clean stove project will help end to Ulan Bator's Dickensian winters.
"I am going to advise my neighbors to buy one as well. Nothing will change if only a few buy it," she said. "When I first came to Ulan Bator 18 years ago, the city skies were clear, maybe if everyone uses this new stove it can be like that again."
Editing by Don Durfee and Ron Popeski