The farming industry displayed an 'astonishing' attitude to the risk of 'mad cow disease' being transmitted to humans through contaminated offal, former chief medical officer Sir Kenneth Calman told the BSE inquiry this week.

Sir Kenneth said he was 'concerned' about the potential impact on the NHS of any epidemic of new variant Creutzfeldt-Jakob disease, the human form of BSE. 'The implications for neurology, pathology, nursing and other services would have been considerable.'

He told the inquiry he had issued assurances that the risks were 'theoretical' in the belief that potential disease carrying agents had been removed from carcasses under the specified bovine offal order.

But in October 1995 - six years after the first restrictions on offal for human consumption - chief veterinary officer Keith Meldrum told him about four cases where 'spinal cord had been found still attached to bovine carcasses'.

The following day, officials admitted to Sir Kenneth that cases of BSE in animals born after the 1989 ban on cattle foodstuffs containing specified bovine offal meant it 'may well have got into animal feed because of inadequate controls at slaughterhouses'.

'My concern was that the farming and slaughterhouse industry did not realise just how serious this might be for them, never mind for public health, ' Sir Kenneth told the inquiry.

He contrasted the farming industry's actions to the pharmaceutical industry's when faced with fears about bovine ingredients in vaccinations and medicines.

In 1988 and 1989, a 'rapid review' of medicines led by the medicines control and medical devices agencies ensured any products that contained bovine derivatives were sourced from outside the UK.

'Once the decision was made, the pharmaceutical industry turned it round very fast.' Sir Kenneth said.

Sir Graham Hart, permanent secretary to the Department of Health until November 1997, told the inquiry that officials had always recognised the potential impact of BSE on health: 'I don't think anybody at the time tried to gloss over that there was a risk.'

But, Sir Kenneth said, 'we still do not know what the scale of the problem will be because of the long incubation periods'.

By the end of 1995, six cases of CJD had been reported to the DoH. Two teenagers had fallen victim to the disease, which usually strikes people aged over 60.

There had been only six cases of CJD in people aged under 30 anywhere in the world in the previous 70 years. But by the end of August this year, there had been 29 cases of new variant CJD in young people in the UK.

It was not until March 1996 that the specialist committee set up to advise health ministers on the risks of BSE crossing to humans discovered 'a cluster of cases of CJD' in young people and 'a new variant of CJD'.