Two boys - one of whom died last January - and a girl were all pupils in the same tutor group at Sir James Smith's Community School, in Camel- ford. The Director of Public Health for Cornwall and the Scilly Isles, Dr David Miles, said at a news conference in Truro yesterday that it was "remarkably unusual" for three cases to occur in the same group.
Dr Miles said the three children had been diagnosed with different sorts of leukaemia. Investigations would take some time, he said, but added that, in his view, it was extremely unlikely that there was any link with the water-pollution incident in 1988. None the less, he is seeking expert advice from the Department of Health.
But after the news conference, a campaigner for investigation of the Camelford incident, Elizabeth Sigmund, said there now had to be a full public inquiry into the possible after-effects of the pollution.
The number of expected cases of leukaemia in children aged up to 16 in the county would normally vary between three and nine a year.
The headteacher of the St James Smith School, Angela Perlmutter, said they had been assured levels of the naturally occurring radioactive gas radon were within acceptable limits when last tested, but she had asked for another test as soon as possible. Cornwall has some of the highest levels of radon in air for the whole of Britain.
Dr Miles said since the pollution incident hospital admissions for patients in the area had been monitored, but no particular trends had emerged.
Asked why the cluster of cases had developed in this year group, Dr Miles said: "Everything is speculation." And added: "We will be working to see whether there is a common factor but there is nothing obvious." He said there had been no other cases of childhood leukaemia in the Camelford area since 1984.
Dr Miles said they would be looking at any possible link with electromagnetic fields from high-voltage electricity cables in the area. He said other pupils in the 25-strong tutor group would be offered a blood test next week if their parents were worried.