A Chinese official said on Saturday that "very limited amount of" chemicals had been involved when rockets were fired to blow away rain clouds from Friday's Olympic Games opening ceremony.

"The chemicals will not threaten Beijing's air quality," Wang Hui, Director of Media and Communications Department of Beijing Organizing Committee for the Olympic Games told a press conference in Beijing.

She said 15 kg of silver iodide were spread in an area of 10,000 square kilometers on Friday evening, or more than one gram on each square kilometer on average, which is below the national standard set for drinking water, citing weather departments.

More than 1,000 rain dispersal rockets were fired on Friday evening in Beijing to keep the rainfall outside the city.

Achim Steiner, Executive Director of the United Nations Environment Program, who was at the conference, said the city was doing experiments on rain dispersing and had some capacity to carry out the move.

He said, however, human interference of rain should not be a primary method in environment management.

The pollution reading was 79, within the range of "fairly good", Du Shaozhong, deputy director of the Beijing Municipal Bureau of Environmental Protection said at the press conference.

The air quality in Beijing on Saturday, the first day of the 29th Olympic Games, is suitable for all scheduled matches, including the cycling road race, he added.

The International Olympic Committee has warned it might reschedule endurance events to avoid health risks amid concerns over pollution.

(Xinhua News Agency August 10, 2008)