BEIJING, Aug. 15 (Xinhua) -- The Olympic host city reported on Friday Grade I, or excellent, air quality thanks to days of rainfalls, and the China Environmental Monitoring Center (CEMC) forecast the city would also breathe excellent air on Saturday.

    CEMC's figures revealed that Beijing's Air Pollution Index (API) showed a reading of 17 on Friday, which fell into Grade I, whose API reading ranges between 1 and 50.

    China uses the API system to report the country's air quality. An API reading between 51 and 100, or Grade II, means the air quality is fairly good. An API reading between 101 and 200, or Grade III, entails the air quality is slightly polluted.

    CEMC also forecast that Saturday's air quality in Beijing would also be excellent with the API reading falling between 30 and 50.

    Two days of excellent air quality came after the capital city was swept by rainfall, sometimes heavy, this week.

    Earlier on Thursday, the Beijing Youth Daily quoted a Beijing environmental official as saying that the city's air quality had been in Grade II or better since Aug. 1.

    Du Shaozhong, deputy director of the Beijing Municipal Bureau of Environmental Protection, said the host city saw several muggy days around the opening of the Beijing Games on Aug. 8 but the air quality during that time period was fairly good.

    "In hot and humid weather, people might not feel comfortable. But the air quality at that time still was within the standards," he said.

    Du attributed good air quality to the emissions control measures taken by the city authorities and its neighboring areas before and during the Beijing Olympics and Paralympics.

    In one of these measures, Beijing has imposed an odd-even restriction system based on licence plate numbers that would keep vehicles off the road on alternate days from July 20 to Sept. 20.