A mustard gas warning is going out to developers planning to build near York, the Evening Press can reveal today.

The Environment Agency is advising builders at Clifton Moor to take precautionary measures - such as wearing gloves to avoid skin contact with soil - because of fears that some of the former wartime airfield may be contaminated by the lethal gas.

It fears the chemical weapon may have been spilt on the RAF base during the war, when two gas bombs are believed to have been accidentally dropped.

Now City of York Council, after learning of the agency's concerns from the Evening Press, intends to issue its own warnings to builders submitting planning applications.

Environment protection manager Paul Robinson said after speaking to the agency: "We had not been officially informed that there was a problem there.

"When the mustard gas was spilled it was cleaned up at the time but there is a possibility that there could still be some contamination underground. Mustard gas is fairly nasty but it does break down in time.

"From now on we will also warn developers who intend to build on that site."

But he stressed that as far as he was concerned, there was no danger to the public.

Environment Agency spokesman Mark Morton, speaking from his office, ironically based on Clifton Moor, said: "We are talking about a very big area of land but only a small patch of which may be affected. The problem is we have no exact location.

"When we have been getting planning application through for this site, I have been putting a note in to say that mustard gas may have been spilled and that adequate precautions should be taken based on that information.

"We are relying on hearsay ourselves. We know that the ground was decontaminated at the time, but we have no idea how much land was affected."

He stressed there should be no risk to people shopping or working on the site: any potential problems might arise when the ground was being disturbed. He thought it conceivable but unlikely that local householders digging up their gardens could be at risk.

Robbie Burnett, vice-chairman of the Clifton Moor Business Association and also manager of the Clifton Moor shopping centre, said he had not been aware of such concerns.

"I have never heard of anyone becoming ill from working on the site, and I have been here for nine years," he said. If workers had gone off sick for more than three days through their conditions of work, the matter would have had to be notified to the Health and Safety Executive.

A BBC TV documentary, Home Ground, last night reported how Clifton Moor is one of numerous secret sites established in the war to store mustard gas bombs. Others include RAF airfields at Acaster Malbis, Helperby, Dishforth, Leeming, Linton-on-Ouse and Topcliffe.

Bomb disposal experts were forced to flee after discovering a cache of the live bombs - some of which were leaking - during a routine investigation in West Cottingworth, near Escrick.

Mr Morton said forthcoming legislation should make information about mustard gas storage sites more readily available in future.

Mustard gas causes skin to blister, redden and become sore. If inhaled, blisters will form in the lungs, and pneumonia and blood poisoning can result from severe exposure.

See COMMENT Past dangers still haunt us

Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.