By Michael Bristow
BBC News, Beijing
Pollution has not been the nuisance that some feared
China has confirmed something that most people in Beijing for the Olympics already suspected - the city's air quality has been good.
Environmental officials say pollution levels have met expected standards on every day of the Olympics so far.
They say this is down to measures brought in to reduce emissions during the Olympics and Paralympics.
But one pollution expert says Beijing has also benefited from favourable weather conditions.
Du Shaozhong, of Beijing Municipal Environmental Protection Bureau, said air quality had been good on every day in August.
"We have had 100% compliance days in August and nine great single days," he said at a news conference.
He said reduced pollution levels showed China's emergency measures to guarantee clean air for the Olympics had worked.
"Without these measures... the current air quality would have been impossible," said Mr Du, deputy director of the environmental bureau.
These measures include temporarily closing down polluting factories in and around Beijing, and taking up to half the city's vehicles off the roads.
"Compared with previous host cities, Beijing has taken [the] most intense efforts in cutting emissions and ensuring no pollution," Mr Du added.
Boon for residents
The BBC's own effort to monitor air quality during the Olympics confirms the Beijing government's upbeat assessment.
We have been measuring the levels of particulate matter - just one pollutant - in the atmosphere.
According to our data, Beijing met the strictest WHO standard for particulate matter in six out of the first 11 days of the Games.
Beijing residents - who often have to endure smoggy days when visibility is reduced to just a few hundred metres - have noticed the difference, as have the athletes.
International Olympic Committee spokeswoman Giselle Davies said the IOC always believed Beijing would meet air quality targets.
"Many people thought it would be [a problem], but the fact of the matter is that the concerns were unfounded," she said.
That is not quite the case. IOC President Jacques Rogge himself expressed his concerns about Beijing's pollution last year.
And right up to the start of the Beijing Games, the IOC was saying endurance events could be postponed if pollution levels were too bad.
Independent air pollution expert Ivo Allegrini, in Beijing to monitor air quality during the Olympics, agreed China had managed to reduce pollutants.
But he added that good weather conditions, such as rain, had also played a part.
"Air pollution depends on a combination of the emitting source and the meteorological situation," said Mr Allegrini, of the Italian National Research Council.
"Here in Beijing, we had favourable meteorological conditions coupled with some reduction of emissions."