Special report:   2008 Olympic Games    

    BEIJING, Aug. 4 (Xinhua) -- After three consecutive days reporting top level air quality, Beijing's pollution rating is expected to slip to the second level on Monday, an official said.

    "By noon, the average air pollution index is likely to be around 80," said Beijing Municipal Bureau of Environmental Protection deputy director Du Shaozhong at a press conference on Olympics preparation. But the number is still in line with the "blue sky" standard.

    A pollution reading below 50 is classed "excellent," 51 to 100 "fairly good," 101 to 200 "slightly polluted," 201 to 300 "poor," and over 301 is "hazardous," according to the bureau.

    "Car restrictions and other pollution-reduction measures are paying off, and the air quality in July has improved compared with last year. Traffic-related pollution had dropped significantly since July 20," said Du.

    Figures for August 1 were 28, for August 2, 34, and for August 3,35 on the index.

    The city has imposed an odd-even system based on licence plate numbers that will keep vehicles off the road on alternate days from July 20 to Sept. 20.

    Beijing's neighboring municipality Tianjin and the nearby provinces of Hebei, Shanxi and Shandong, plus the Inner Mongolia Autonomous Region, are also helping the capital to attain its anti-pollution goals by closing major polluters, removing high-emission cars from roads and restoring grassland vegetation.

    Last month saw 26 registered "blue sky" days, or days with fairly good air quality, three days more than in the corresponding period last year, according to data from 27 monitoring station.

    "We have maintained top level air quality for the past three consecutive days, which is an unprecedented case in recent years," said Du.

    "We are confident in saying that if the situation remains stable then measures will guarantee the air quality during the Olympic Games," said Du.