Ger districts: a main source of pollution, and home to its victims
Ulaanbaatar is the most polluted capital city in the world in terms of PM index, according to a study by Prof. Lodoysamba of the National University of Mongolia, who studies Ulaanbaatar air pollution and runs the UB Air Quality Facebook and Twitter page for regular updates on air quality.
“The concentration of particulate matter (PM) in the ambient air varies widely across the city but is, at its very best, several times the national standard limit of 25 µg per square meter for PM2.5,” he explained. “One area of the city has an annual average PM level of 600 µg per square meters.”
Yet, it is Ulaanbaatar’s ger districts, where more than 150 thousand households live, that are often the most affected by the city’s toxic air pollutants. Often, ger district residents burn raw coal or anything else they can find to stay warm during the winter, given the unforgiving -30 degree Celsius climate. The districts continue to expand rapidly, as former herders who have lost their livestock in dzud (harsh winter) and to the effects of mining move to the city in the hope for a better life. In total, ger district homes burn approximately 660,000 tons of coal per year, averaging 4.5 tons per household. The combustion of raw coal makes up more than 60 percent of the microscopic dust or particulate matter in Ulaanbaatar air.
Prof. Lodaysamba’s study revealed that coal combustion in ger district stoves, which contributes most to PM 2.5, emits most of its smoke during the ignition of the stoves. Once ignited, stoves produce relatively little pollution. “Our study concluded that 50 percent of PM concentrations correspond to the ignition phase (cold start) and reloading of stoves,” he said.
He also noted that, somewhat counter-intuitively, warmer days can see higher levels of pollution. As the ignition phase causes most of the smoke and dust in the air, relatively warmer days (-18 to -16 degrees Celsius) are more polluted than extremely cold ones (-30 to -32 degrees Celsius), as most households turn off their stoves on warmer days and reignite them multiple times throughout the day. Whereas on extremely cold days, households ignite their stoves only once and leave them on throughout the day.
By modifying existing stoves, Prof. Lodaysamba and his team were able to reduce emission of PM by 99 percent using raw coal. He did this by, “channelling all emissions and flames into a pipe placed at the back of the combustion chamber. The fire was ignited next to this outlet so that all smoke produced by igniting coal would be mixed with flames and burn inside the pipe.”
“PM emissions are so low that for much of the time, the improved stove substantially cleans the ambient air that passes through it. The chimney gases are usually cleaner than the outdoor air,” he added. “Brown coal is not an inherently smoky fuel. Conditions can be successfully created for burning wood and high moisture materials. High volatiles ignite with very low PM emissions in a practical device.”
Prof. Lodoysamba said that the modified stove that his team developed is much cleaner than the government distributed “full-combustion” stoves developed in Turkey, as the ignition process is very different. He noted that the full combustion stoves weren’t designed for the fuel that is currently available to ger districts, and are mostly ignited in the same manner as the traditional stoves, making them inefficient.
As the modified stoves built by Prof.Lodoysamba require high grade ceramics and steel lids, they cannot be mass produced in Mongolia at an affordable price.
The full-combustion stoves aimed to decrease air pollution by up to 50 percent. As part of a government program to reduce air pollution, the 100 thousand full-combustion stoves were distributed to ger districts at a 93 percent discount, for around 35,000 MNT. The last batch, some 40 thousand will be distributed to ger district households by March, say government officials.
Although Prof. Lodoysamba said that air pollution has decreased noticeably this year, he admitted the possibility that this year’s abnormally warm winter might be the reason for it. Meteorologists say that this winter is the warmest in 40 years.
To reduce air pollution, the World Bank has suggested that Ulaanbaatar reduce stove start-up emissions or replace stoves and improve fuel, build a new power plant and install electric heaters in gers, and relocate ger district households to apartments.
Prof. Lodoysamba made an assessment of annual health benefits from abatement scenarios. He highlighted that the annual health benefits of transferring to energy sources for heat such as installing electric heaters or utilizing natural gas will be much more cost efficient than relocation to apartments in the short and long-term. In the near-term, the issue is unlikely to be resolved anytime soon, but it is clear that certain measures can be made to fight the issue now.
Short URL: http://ubpost.mongolnews.mn/?p=7531
“The concentration of particulate matter (PM) in the ambient air varies widely across the city but is, at its very best, several times the national standard limit of 25 µg per square meter for PM2.5,” he explained. “One area of the city has an annual average PM level of 600 µg per square meters.”
Yet, it is Ulaanbaatar’s ger districts, where more than 150 thousand households live, that are often the most affected by the city’s toxic air pollutants. Often, ger district residents burn raw coal or anything else they can find to stay warm during the winter, given the unforgiving -30 degree Celsius climate. The districts continue to expand rapidly, as former herders who have lost their livestock in dzud (harsh winter) and to the effects of mining move to the city in the hope for a better life. In total, ger district homes burn approximately 660,000 tons of coal per year, averaging 4.5 tons per household. The combustion of raw coal makes up more than 60 percent of the microscopic dust or particulate matter in Ulaanbaatar air.
Prof. Lodaysamba’s study revealed that coal combustion in ger district stoves, which contributes most to PM 2.5, emits most of its smoke during the ignition of the stoves. Once ignited, stoves produce relatively little pollution. “Our study concluded that 50 percent of PM concentrations correspond to the ignition phase (cold start) and reloading of stoves,” he said.
He also noted that, somewhat counter-intuitively, warmer days can see higher levels of pollution. As the ignition phase causes most of the smoke and dust in the air, relatively warmer days (-18 to -16 degrees Celsius) are more polluted than extremely cold ones (-30 to -32 degrees Celsius), as most households turn off their stoves on warmer days and reignite them multiple times throughout the day. Whereas on extremely cold days, households ignite their stoves only once and leave them on throughout the day.
By modifying existing stoves, Prof. Lodaysamba and his team were able to reduce emission of PM by 99 percent using raw coal. He did this by, “channelling all emissions and flames into a pipe placed at the back of the combustion chamber. The fire was ignited next to this outlet so that all smoke produced by igniting coal would be mixed with flames and burn inside the pipe.”
“PM emissions are so low that for much of the time, the improved stove substantially cleans the ambient air that passes through it. The chimney gases are usually cleaner than the outdoor air,” he added. “Brown coal is not an inherently smoky fuel. Conditions can be successfully created for burning wood and high moisture materials. High volatiles ignite with very low PM emissions in a practical device.”
Prof. Lodoysamba said that the modified stove that his team developed is much cleaner than the government distributed “full-combustion” stoves developed in Turkey, as the ignition process is very different. He noted that the full combustion stoves weren’t designed for the fuel that is currently available to ger districts, and are mostly ignited in the same manner as the traditional stoves, making them inefficient.
As the modified stoves built by Prof.Lodoysamba require high grade ceramics and steel lids, they cannot be mass produced in Mongolia at an affordable price.
The full-combustion stoves aimed to decrease air pollution by up to 50 percent. As part of a government program to reduce air pollution, the 100 thousand full-combustion stoves were distributed to ger districts at a 93 percent discount, for around 35,000 MNT. The last batch, some 40 thousand will be distributed to ger district households by March, say government officials.
Although Prof. Lodoysamba said that air pollution has decreased noticeably this year, he admitted the possibility that this year’s abnormally warm winter might be the reason for it. Meteorologists say that this winter is the warmest in 40 years.
To reduce air pollution, the World Bank has suggested that Ulaanbaatar reduce stove start-up emissions or replace stoves and improve fuel, build a new power plant and install electric heaters in gers, and relocate ger district households to apartments.
Prof. Lodoysamba made an assessment of annual health benefits from abatement scenarios. He highlighted that the annual health benefits of transferring to energy sources for heat such as installing electric heaters or utilizing natural gas will be much more cost efficient than relocation to apartments in the short and long-term. In the near-term, the issue is unlikely to be resolved anytime soon, but it is clear that certain measures can be made to fight the issue now.
Short URL: http://ubpost.mongolnews.mn/?p=7531
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