AsianScientist (Sep. 3, 2012) – A new study has found that Tibetans around the sacred Nam Co Lake in Tibet breathe in almost perfectly clean air.
The Aerosol Optical Depth (AOD) of air samples stood at 0.029, a reading comparable to that in Antarctica, said Cong Zhiyuan, deputy head at the Qinghai-Tibetan Plateau Institute under the Chinese Academy of Sciences (CAS).
The AOD measures the degree to which aerosols prevent the transmission of light by absorption or scattering of light. The lower the reading, the cleaner the air.
According to the United States Environment Protection Agency, particles less than 2.5 micrometers in diameter (PM2.5) are referred to as “fine” particles and are believed to pose the greatest health risks. Because of their small size – at approximately 1/30th the average width of a human hair, fine particles can lodge deeply into the lungs.
The PM2.5 reading of the Nam Co area on an average day was 10 micrograms/cubic meter, in comparison to the average PM2.5 reading in Chinese capital Beijing from Wednesday to Thursday which was 137 micrograms/cubic meter.
A popular visitor destination in summer, Nam Co Lake lies 260 kilometers to the south of Lhasa, the administrative capital of the Tibet Autonomous Region. The name Nam Co means ‘heaven’ in Tibetan Chinese.
The air quality is excellent because most residents are herders and there is little human activity around the lake, said Kang Shichang, a CAS research fellow stationed at Nam Co.
At an elevation of 4,718 meters above sea level, Nam Co is the highest lake of its kind, and the second biggest salt water lake in China.
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Source: Xinhua News; Photo: Pet_r/Flickr/CC.
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