Children who have alleged their birth defects were due to their mothers' exposure to toxic waste, have been told their claim was a "delusion".
Corby Borough Council denies negligence concerning reclamation works at the site of a former British Steel plant.
The eighteen children were born with deformities to their hands and feet.
Stephen Grime, QC for the council, told the High Court the numbers of children in Corby with such deformities were "normal" for the population size.
The group of young people, aged between nine and 22, are suing Corby Borough Council.
The council denies their claim that it was negligent during reclamation works at the town's former British Steel plant between 1985 and 1999.
The group's counsel, David Wilby QC, has told Mr Justice Akenhead that the disabilities were caused early on in their foetal development when their mothers ingested or inhaled an "atmospheric soup of toxic materials" from the redevelopment.
Mr Grimes argued that there was a danger in being seduced by the idea of "clusters" of cases.
He cited an instance in the 1990s when a number of children with limb defects were born in the Isle of Wight within a relatively limited period and it was suggested that this "cluster" was connected with pollutants in the sea.
An investigation later concluded that this cluster and other similar clusters were chance events.
"The message from that is that there is a seductive attraction to clusters but what one has to do is to look behind that," he said.
Mr Grime hoped that when the judge visited Corby for a site visit on Wednesday, he would see a town which had not become a "rust bucket" but had achieved a measure of economic success.
The case continues.