Thickening air pollution has shrouded the Chinese capital in a nasty haze and local people were advised to reduce their time outdoors.

According to the Beijing Meteorological Bureau, Wednesday was the city's most polluted day this year. The air quality index was listed at five, the worst rating on a five-point scale, indicating that air quality was hazardous.

"The city has witnessed three consecutive days of harmful air. Visibility in most parts of the city has been only about one kilometer, in sharp contrast with previous days," it said.

The bureau said warm currents in the upper atmosphere, relatively cool currents in the lower atmosphere and a lack of wind combined to cause the toxic weather.

"Dust raised by construction sites and vehicles and the spring drought have also contributed to the pollution," it said.

Remote sensing found similarly widespread haze in neighboring Hebei and Shanxi provinces and the middle and lower reaches of the Yangtze River.

On April 5, the particle density of the air was about 445 micrograms per cubic meter in Beijing, according to recent pollutant readings released by local air quality monitoring centers.

"For their health's sake, people should stay indoors or try to reduce the time spent outdoors," said a warning by the Beijing Environmental Protection Bureau.

But meteorologists also told good news. "There will be a powerful wind blown into the city today which will disperse the haze," said an expert with a Beijing weather center.

Statistics show that by March 31, Beijing had enjoyed 62 days of excellent or fairly good air quality this year, 69 percent of the total days and 10 days more than the same period last year.

(Xinhua News Agency April 7, 2005)