The haze that reduced visibility for a few days till Monday did not mean Beijing's air quality was bad, a senior city environmental official said Tuesday.

"Clouds and haze are not pollution. This kind of weather is a natural phenomenon. It has nothing to do with pollution," said Du Shaozhong, deputy director of the Beijing municipal bureau of environmental protection.

A rare dry spell last week is to blame for the haze that shrouded Beijing a couple of weeks before the Olympic Games, Du said at his sixth press conference in five days at the Main Press Center.

But Monday night's showers and strong breeze drove away the haze, offering residents a blue sky Tuesday morning. The city's air pollution index was 90, which denotes good air quality.

Weather officials believe Beijing's air quality will improve further when days get cooler in just a week.

"The temperature and humidity will drop gradually and, we will have better air quality and more comfortable weather in August," said Guo Hu, director of Beijing Meteorological Observatory.

But even when the haze had shrouded the city, the density of carbon monoxide, nitrogen dioxide and respiratory suspended particulates in the air dropped 20 percent year-on-year, Du said.

That was made possible by the traffic restrictions imposed from July 20. The new traffic arrangement allows vehicles with even and odd number plates to hit the roads on alternate days only.

Photographs do not always tell the real story, he said. Some media agencies have projected the haze over Beijing as smog, and deliberately used it as a sign of the high pollution level in the city.

Such photographs "don't tell the truth", he said. "We don't approve of their use to pass judgment on the air quality ... you have to look at the complete monitoring system, and analyze the data scientifically."

Other pre-Games green measures include closing polluting factories in and around Beijing, suspending work on most urban construction projects and banning vehicles that fail to meet emission standards.

Beijing has some special plans, too, to improve the air quality, Du said. But they will be implemented only if the air quality deteriorates during the Olympics.

"We have to pay more attention to the measures already underway to improve the air quality. These are the foundation of our work," Du said.

Gilbert Felli, International Olympic Committee's executive director for the Beijing Games, said he was confident about the city's air quality.

Most people see the haze and mistake it for pollution, Xinhua quoted Felli as having said. But "we know here it's not pollution. It's a fact of nature. Hopefully more rain will clear the sky further".

Earlier, during a media tour of the Beijing Public Transport Control Center, Du said the 20,400 environmental-friendly buses have reduced the emission level by 15 to 20 percent.

Beijing has one of the world's largest fleets of buses running on natural gas, said Feng Xingfu, vice-general manager of Beijing Bus Company.

(Xinhua News Agency July 30, 2008)