FACTBOX-Key facts about Beijing's hard-to-clear smog
28 Jul 2008 09:31:50 GMT Source: Reuters
(For related story see OLYMPICS/POLLUTION or [ID:nPEK86301]) July 28 (Reuters) - Haze-shrouded Beijing may take more cars off the roads and shut more factories if air quality remains a problem during the Olympic Games, state media said on Monday. The pollution has proved hard to shift days before athletes and visitors arrive, despite the implementation of two month even-odd car ban and temporary factory closures. Here is some background about clean air and smog in Beijing, host of the Aug. 8-24 Olympics. * CLEAN AIR VS POLLUTED AIR: -- Clean air is a balance of nitrogen (78 percent), oxygen (21 percent), water vapor, and small amounts of inert gases such as neon, carbon dioxide and helium. -- Air pollutants -- substances not naturally occurring in the atmosphere -- affect this balance. -- Main air pollutants include particulate matter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), volatile organic compounds (VOCs) and carbon monoxide (CO). * BEIJING'S MAIN AIR POLLUTANTS: -- Particulate matter, a mix of dust, dirt, soot, smoke and various droplets emitted from cars, factories, coal-burning boilers and construction sites, is Beijing's worst pollutant. -- While Beijing's SO2, CO and NO2 levels decreased from 2000 to 2006, PM10 concentrations did not, the UNEP said. -- Beijing's 3.3 million cars pump out 80 percent of the colourless carbon monoxide in its air, according to the United Nations. * WEATHER ISSUES: -- Experts say attempts to lift Beijing's smog are complicated by weather and atmospheric conditions, which influence how pollutants are transported of pollutants, and how easily they combine into new compounds or are dispersed. -- Wind, for example, carries smog, but can also disperse it. On cloudy days, with warm moist air, sulphur dioxide can be more quickly converted into a particulate. On hot, still, days ozone pollution is typically worse. * SUMMER POLLUTION: -- Beijing's hot, sunny, summers are ideal for forming ground-level ozone, the result of nitrogen oxide and volatile organic compounds reacting in the presence of heat and sunlight. -- Frequently hit by spring sandstorms carried by strong cold Siberian winds from northern deserts; Beijing's occasional summer sandstorms have been blamed on continuous hot dry local weather creating dry, unstable dust in the city. * GEOGRAPHICAL PROBLEMS: -- Pollutants from industries outside Beijing also blow in. Domestic coal burning and pollution from coal-fired power plants in neighbouring Shanxi, Inner Mongolia, and Hebei that supply electricity to the capital all contribute to the capital's smog. -- Beijing is surrounded by mountains that prevent pollutants from dispersing, and allow smog to settle over it. Sources: Reuters, United Nations Environment Program, Greening Beijing report, (http://www.unep.org/sport_env/documents/beijingreport07/chapter 5.pdf) (Writing by Gillian Murdoch, Beijing Editorial Reference Unit; Editing by Valerie Lee) (For a video of latest smog conditions, see http://www.reuters.com/news/video?videoId=86131&videoChannel=74. For more stories visit our multimedia website "Road to Beijing" at http://www.reuters.com/news/sports/2008olympics; and see our blog at http://blogs.reuters.com/china) ((For a TAKE A LOOK double click on [ID:nSP39402]))
Smoke billow from an indoor stadium that is being built for next year's 11th China National Games, in Jinan, Shandong province July 27, 2008. The indoor stadium was damaged by a ...
