These low levels of methane that are self-igniting or explosive

Lesley McCarthy, the Rebecca group

Government-backed research which appeared in the British Medical Journal found a 1% higher risk of congenital abnormalities for those living within 2km of sites and 7% higher for those living near hazardous waste.

Outline planning permission has already been granted and Newport County Council has said it will make the site safe.

It said it was working with the Environment Agency to ensure safety procedures are followed.

Risk assessment

But children's rights group Rebecca - Children's Right to a Safe Environment - has called on the National Assembly for Wales to scrap the plan.

The organisation claims a full risk assessment was not carried out on the proposals.

Lead campaign Lesley McCarthy said an assessment document put together by the council was "a lot of bald statements and a few factual inaccuracies cobbled" and not the detailed risk assessment called for by Welsh Environment Minister Sue Essex.

Val Jean said the plan could not be justified

She said the report has glossed over facts relating to methane on the possible school site.

"Yet it is these low levels of methane that are self-igniting or explosive," she said. "The explosive aspect is not even pointed out.

"If the likely outcome of these procedures was not harm to children, it would be farce."

"We, parents and their supporters have pointed out time and time again to the assembly the antics of the council, which are highly likely to result in children being harmed."

Rebecca has called on the assembly to use reserve powers to pull the scheme away from the council.

Assurances

Vale Jeans of the Glebelands Action Group said: "There were no reassurances.

"I cannot see how they can justify putting a school on a site that is poisonous."

But the local authority has said it will not start work until the site has been deemed safe.

Parents living near the Nantygwyddon landfill in the Rhondda claim birth defects in their children could have been caused by the tip., which is under an assembly investigation.

They cautiously welcomed the results of the 11-year research which showed some link between health problems and proximity to landfills.

The report also showed that 80% of the population of the UK lived within 2km of such sites.