Pollution weakens, health risks remain

Pollution levels in most parts of Beijing have been downgraded to level four, signifying an "unhealthy" level of pollution, as local residents put up with another day of noxious air. The China Meteorological Center issued a yellow alert on Tuesday morning, as parts of central and eastern China continues to be shrouded in smog.

PM 2.5 data citywide hovered around 200, a significant improvement on the weekend, but still exceeding 150, the level at which pollution is considered "unhealthy".

The orange alert issued on Sunday has been lifted as visibility levels have improved.

Other parts of the country have yet to recover from the dense smog. A 24 hour forecast from the China Meteorological Center shows that parts of Shandong, Henan, Jiangsu and Anhui provinces will continue to see heavy smog until Wednesday afternoon. A light fog is also forecast for surrounding provinces.

Zhang Huafang, chief forecaster of China Meteorological Center, said,"The China Meteorological Center has issued a yellow alert to these regions, where visibility could drop to less than 1,000 meters. In some parts, it could fall to below 200 meters. "

A combination of high humidity levels, low winds and the lack of a cold front is believed to create atmospheric conditions in which pollutants get trapped and hang in the air.

Zhang Huafang said,"Fog is a natural phenomenon. In itself fog poses no harm to human health. The only way to improve air quality and prevent smog forming is to cut fuel emissions. "

A cold front is about to sweep to the rescue from Wednesday, with temperatures dropping by between four and eight degrees celsius. Nationwide, the weather is expected to improve from Thursday, with no smog expected for the next five days at least.

Zhang Nini said,"Rarely do people in Beijing wish for cold winter winds, but that's the case now. Sadly, the current bout of smog is just one of many smoggy episodes in the Chinese capital. When a city is reduced to relying on wind to clear heavy pollution, one has to ask, what can we do to improve the air we breathe?"