BEIJING, Jan. 23 (Xinhua) -- The air quality in Beijing Municipality on Wednesday hit serious levels again, as smog blanketed the city.
At 9 a.m., air quality indices in most monitoring stations in the city proper exceeded 300, or Level VI, a serious level, according to statistics from the Beijing Municipal Environmental Monitoring Center.
A high concentration of fine particle pollutants was spotted moving from southeast Beijing from 3 p.m. Tuesday before shrouding the entire city, said an official with the center.
The PM2.5 data, a gauge monitoring airborne particles of 2.5 microns or less in diameter which can embed deep in people's lungs, reached 200 to 300 micrograms per cubic meter, indicating heavy pollution, he said.
The weather forecasting bureau has issued yellow alerts for both fog and smog, the third highest level.
Visibility in south Beijing will fall below 500 meters on Wednesday, and most of the city will see visibility drop to less than 3,000 meters.
According to the weather forecast, strong winds with speeds of 20 to 30 km per hour will sweep the city on Wednesday evening and are expected to disperse the smog.
Beijingers suffered from heavy smog from Jan. 10 to 16, before the putrid air was dispersed by a cold front bringing strong winds. Air quality indices were off the charts during the seven days, exceeding the "maximum" level of 500 in the city, as well as many other cities in central and north China.