Sunday 15 April 2001 Sundaay Telegraph

By Robert Matthews, Science Correspondent

GOVERNMENT scientists have admitted they have no hard evidence that it is safe for animals with foot and mouth to be burned in the open.

Official assurances that the virus is not spread by smoke from open pyres are based on little more than guesswork, a Telegraph investigation has discovered. Many scientists and farmers have expressed concerns about the possibility of worsening the epidemic through such open burning.

When The Telegraph put the point to the Ministry of Agriculture, Fisheries and Food (Maff), the official response was that the risk of spreading the disease in this way was "extremely, extremely low", as the concentration of virus was diluted by hot air in the pyres. The spokesman insisted that the factual basis of this assertion was "established scientific evidence".

However, further questioning revealed that this consisted entirely of theoretical calculations and estimates. After requests for clarification, a Government spokesman admitted that no measurements or air sampling had been performed around the pyres. He said: "It is paper-based research."

The studies are believed to be based on rough estimates and data drawn from studies of purpose-built incinerators, which operate at far higher temperatures than open pyres. Any conclusions based on such research could prove hopelessly misleading.

Experts on combustion point out that - in contrast to purpose-built incinerators - there is no guarantee that when infected animals are thrown on a pyre the virus is exposed to high enough temperatures for long enough to destroy it all.

Anthony Burgess, the visiting professor of combustion science at University College London, said: "Anyone who has run a bonfire knows that the material at the edge doesn't catch fire, and that the temperature drops very quickly."

Concern focuses on the fact that the virus is contained in an animal's body fluids. These are released when carcasses explode in the heat of the fire, sending infectious material into upward hot air currents. Any surviving virus could then be blown by winds for miles.

Ken Tyrrell, who was in charge of Cheshire's Maff team during the 1967 foot and mouth outbreak, said that the consequent inquiry had called for carcasses to be buried rather than burnt because of the risk of spreading the virus. Professor Burgess called for urgent tests to be carried out on a real open-air pyre to assess the risk.

The admission by the Government that pyres have not been independently scientifically examined comes amid fears that the whole of Britain may be engulfed by the epidemic. Last week, the virus "jumped" distances of tens of miles.

Then, in Northern Ireland yesterday, tests confirmed that the province has suffered a fresh outbreak, despite having been given the all-clear. Maff, which says it has no figures for the number of open-air pyres throughout Britain, would prefer disposal through rendering, incineration and burial.

The scale of the epidemic, however, has proved too great for these methods. So far, more than a million animals have been slaughtered - two and a half times the total killed in 1967. The backlog of carcasses awaiting disposal is about 400,000.

Burning at Britain's biggest foot and mouth pyre - designed to dispose of 3,000 carcasses a day - was halted last week only three days after it began following protests from neighbours about potential health risks. Maff officials are now awaiting a decision from Nick Brown, the Agriculture Minister, about what to do with the massive pyre at Hallburn airfield, near Longtown, Cumbria.

Peter Tiplady, Cumbria's public health director, called for a detailed study of the affects of such large pyres. He said there was a risk, though very small, that they could release into the air BSE prions - thought to cause variant CJD in humans - and other toxic agents.