With the Olympics just a month away, the air quality in Beijing is still failing to meet international standards - according to tests carried out by the BBC.

The level of pollution in the Chinese capital has been one of the major concerns since it was awarded the Games seven years ago.

Beijing's bid included a commitment that the city's air would meet World Health Organisation standards by the time the Olympics began.

But, using a handheld detector to test for airborne particles known as PM10, the BBC found the air there failed to meet the WHO's air quality guidelines on six days out of seven.

PM10 particles are caused by traffic, construction work and factory emissions, and are responsible for much of Beijing's pollution.

The BBC found that on one of the days tested, the pollution reading was seven times over the WHO's air quality guideline, whereas readings taken in London - the site of the 2012 Games - all fell within acceptable limits.

Beijing officials have previously insisted they will fulfil their clean-air promise.

The city's air is expected to begin clearing this month as strict, two-month pollution controls come into force July 20.

Factories and heavy industry in several provinces around the capital will be temporarily shut down, and up to two million vehicles will be taken off the roads using an even-odd plate registration system.

International Olympic Committee president Jacques Rogge has previously warned some outdoor endurance events lasting more than an hour will be postponed if Beijing's air quality is found to be poor.

The IOC remain hopeful the air quality in Beijing will improve markedly leading up to the Games.

Hein Verbruggen, chairman of the IOC's co-ordination commission for Beijing 2008, said: "Here in the Chinese capital you can now really sense the excitement and anticipation. The city feels ready; it looks ready, with the stunning venues all completed."

He added: "A very small number of open issues remain - such as some matters with broadcasters and our need to see how temporary measures in the city will make an impact on air quality.

"But across the board... we are satisfied. When athletes, sports officials, spectators and media arrive in this city over the coming weeks, I have no doubt they will be impressed when they see things with their own eyes; and they will be touched by the warmth of the welcome the Chinese people will show them."

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