Just before the start of the big games, the World Health Organization claimed that the pollution near the Olympic stadium in 2008 was five times over the standard considered safe. In an attempt to remove the pollution for the games, the government ordered to remove done million cars from the streets. Other sources including satellite data depict Beijing to be the worst victim of China's economic Growth.
Recent compilations of smog levels recorded in the Air Pollution Index record the quality of Shanghai air to be between class I and Class II. According to NASA, reasons for this build up of pollution over Eastern regions of China could be due to the altitude of cool air being denser than the layer of warm air above it. Because of this disparity in density, the two layers of air do not mix, and the pollutant filled air builds in regions like Shanghai.
Contributing Factors to Air Quality
Researchers claim that the PM2.5 particle comes from vehicle exhausts which also contain black carbon, sulfates and nitrates contributing to smog density. When this smog becomes dense, it creates a very low layer of Ozone which is formed by these hydrocarbons and nitrogen oxides. It is especially harmful to people's health when the Nitrogen oxides (NOx) are combining with sunlight. The China National Environmental Monitoring Center considers Guangzhou and Shenzhen to have similar smog problems to Beijing and Shanghai.
According to the China daily, it is likely that even tougher rules for air quality are likely soon. The World Health organization (HWO) issued air quality guidelines in 2005 claimed that the levels of airborne pollutants or smog in China were indeed damaging to health. Some of these air pollutants which contribute to the "haze,'" include sulfur dioxide, nitrogen dioxide and PM10. More than 400,000 premature deaths are deemed to be the result of such pollutants.
Recent measures have made significant efforts to reduce smog levels; the most common type of measures include the closing of factories, and tightening the regulation of traffic levels. As researchers have done numerous studies, findings depict that such preventative action can actually reduce smog levels by approximately 10 to14 percent. Although this seems to be very impacting, it is actually quite difficult to see a visible difference in smog levels.