IT’S A POLLUTION FREE ENVIRONMENT IN LAKE NAMCO- China

Lake Namco, the highest saltwater lake in the world at 4718 meters above sea level, is a sacred lake for Tibetans. Recent study on the air quality of the lake area measured Aerosol Optical Depth (AOD) at 0.029 and PM 2.5 at 10 micrograms/cubic meter on an average day.
31 August
http://eng.tibet.cn/2010hb/xw/201208/t20120831_1772515.html