A group of young people who blame their birth defects on their mothers' exposure to “an atmospheric soup of toxic materials” have won a landmark ruling that a council was negligent in its reclamation of an old steelworks site.

Mr Justice Akenhead's decision clears the way for the 16 successful claimants, aged between 11 and 22, to prove that their particular disabilities were caused by Corby Borough Council's failings — with compensation to follow if they succeed.

The judge's finding at London's High Court that there were no breaches of duty after August 1997 means that two others, aged nine and ten, cannot proceed with their cases.

The council had denied it was negligent during the works at the former British Steel plant between 1984 and 1999, and that there was a link between the removal of waste to a quarry north of the site and deformities affecting hands and feet.

But the judge, who said the council's approach was to “dig and dump”, preferred the evidence of expert witnesses called on behalf of the claimants. He accepted the evidence of waste management expert Roger Braithwaite who said that over 15 years of poorly regulated “muck shifting” polluted the environment of the town.

The judge said that Mr Braithwaite was “obviously appalled” at the way in which the council conducted itself, and concluded: “As is clear from this judgment, he was right to be appalled.”

In his 919-paragraph judgment he said that the council “bit off more than it could chew and did not really appreciate the enormity, ramifications and difficulty of what it was setting out to achieve in terms of removing and depositing very substantial quantities of contaminated material”.

The Corby site was one of the largest steelworks in Western Europe, covering 680 acres.

David Wilby QC, who represented the families, said that legally the ruling was “extremely important”.

“It is the first time in the world that it has been established that airborne pollution can cause birth defects of this type.”

The group's solicitor Des Collins added: “I would like to say how terribly sorry we are that the council put the families through 10 years of anguish in the way they did. It was totally, totally unnecessary.”

He added: “What is even more appalling now is I hear from the council that they, even now, refuse to accept the inevitability of the position they are in.

“They got it wrong. They should simply put their hands up now and admit it. We will have to fight on, but we are quite determined to do that.”