Work and Money

Arsenic, lead, petrol, tar and asbestos are some of the noxious substances found in the soil on the Olympic site, left behind by decades of factories, garages and landfill. A set of 50-tonne soil-washing machines have begun to clean the site of these contaminants.

The Olympic Delivery Authority, which is responsible for delivering the Games, insists that it has found no nuclear waste on the site.

But rumours persist about the presence of radioactive waste on the site, following claims in the mid-1990s that a thorium plant in the area had dumped radioactive waste there.

Independent nuclear consultant, John Large, told BBC London: "It is a matter of public record that radioactive waste was dumped on the site."

He claims that traces of thorium are difficult to detect but could possibly leach out during the Olympic development and pose a health risk.

Simon Wright from the ODA

An impossible challenge

ODA Director of Infrastructure and Utilities, Simon Wright stated: "We've looked long and hard and we've found no evidence of nuclear waste on this site."

The 2.5 square kilometre Olympic site contains 1.4 million tonnes of soil. More than 1,900 boreholes have so far been dug across the site to test soil levels.

The ODA has used Geiger counters that can spot unusual levels of alpha radiation, which is the kind produced by thorium.

John Large replied: "On a site that size to put down a few boreholes doesn’t tell you enough. Boreholes are just like pinpricks. The ODA will never be able to conclusively say that there is no radioactive waste on the site."

Giant washing machines

The ODA's special soil-washing machines will wash, sieve and shake contaminants out of the soil, separating different components so the water and soil can be re-used. The rest will be sent to landfill.

David Higgins, Chief Executive of the ODA, said: "By Beijing 2008 the land will be cleaned and cleared ready for construction of the Olympic Park."

To see the new cleaning machines in action and hear comments from Simon Wright, click on the video link above.

What do you think? Send your comments to me at angela.saini@bbc.co.uk

Your views:

"So long as a responsible body is testing the site for nuclear contamination, that is OK.  Individuals will always have their own opinions. This site would have deteriorated from the ghastly mess it currently is to something far worse, without the funds to stop the rot.  For Heavens sake let us all be positive and stop this negative knocking!" - Michael Waller

"There is a difference between 'cleaning up' an area and the kind of colossal vandalism being perpetrated here. It is very hard indeed to be positive when you see such a rich and unique tapestry of history, communities and ecology being so cynically discarded. The reality is that anywhere in East London you dug a borehole, you'd find contamination of some sort. It was exactly the same contamination story at the Greenwich peninsular and at Docklands. The difference is that redeveloping those areas did not involve demolishing productive industrial estates, community housing, a very popular cycle circuit in a lovely setting and the most beautiful and unique allotment gardens in the East End." - Paul Charman