With the Olympic cycle race coming through highly polluted Putney next month an environmental has report has raised concerns about visitors not being warned about poor air quality.

The Commission for Sustainable London 2012 pre-games review has said raising awareness of poor air quality episodes needs to be resolved in time for the Games.

It said: "The main sustainability concern from the transport experience will be air quality.

"We have expressed concern about the degree to which public health messaging will reach tourists who may not be familiar with London's air quality challenges on days when air quality is poor."

Earlier this year Putney was the first borough in London to breach European Union regulations for levels of nitrogen dioxide (NO2).

And with the men and women's cycle race coming through Putney on July 28 and 29 there will be a lot of visitors descending on the area.

Simon Birkett, founder and director of Clean Air in London said: "This report packs a knock-out punch.The most-respected independent organisation associated with the London 2012 Olympics has revealed clearly the UK’s failure to warn the public during smog episodes.

"The simple fact is that the UK authorities don’t want anyone to know London has the highest levels of nitrogen dioxide, a toxic gas, of any capital city in Europe.

"Let’s not forget either, this issue is not about breaching legal thresholds. It is about the need to warn Londoners and others of smog episodes throughout the year with advice for people on protecting themselves and reducing pollution for themselves and others."