Britain's Foot and Mouth epidemic raises wider public health concerns

The economic costs of the current foot and mouth disease (FMD) epidemic on British farms are well known. Farming has been devastated and tourism has plummeted, as some rural areas have become no-go zones. But now there is widespread concern for public health and the environment, as a result of the slaughter of millions of animals.

Pictures of mass burial sites, funeral pyres and animals lying in fields for weeks have filled the newspapers and TV screens. FMD is a highly contagious animal disease that has infected 1,515 livestock on 5,900 farms since it was first discovered on February 19 at an Essex abattoir. In some of the worst hit areas, such as southern Scotland, over half the farms are directly affected.

The government's policy is to cull all animals on infected premises within 24 hours and on neighbouring farms within 48 hours. The result has been the slaughter or proposed slaughter of nearly two and a half million sheep, cattle and pigs. Another million or more are to be destroyed for welfare reasons.

The disease peaked at 43 outbreaks a day at the end of March and now averages 12 a day. Until now it has mainly affected sheep but there are fears it may increase again, as cattle are brought onto spring pastures.

There are now concerns at the risk of FMD to humans. Although rare and not threatening, it is possible for some people to contract the disease. The symptoms are a milder form of the painful blisters that appear around the mouth, nose and feet in animals. In the current epidemic, public health officials have tested 13 people suspected of catching the disease by touching animals or drinking infected milk. Eight have so far proved negative.

It was several weeks into the epidemic before government departments issued guidelines on the transport and disposal of animals once they had been slaughtered. Officials hurriedly put together advice on the disposal of disinfectants, manure, slurry and milk.

There are serious problems of contamination through footwear, clothing, equipment and vehicles. The virus can be blown by the wind and carried by birds and rodents for great distances. The Environment Agency recommended farmers send dead animals to rendering plants and incinerators. If this was not possible, the Agency said they should be buried in registered landfills. Burning or burying on farms was the least desirable option but, in practice, nearly all disposals have been through this route so far. By March 20, at the height of the epidemic, only one rendering plant had been chosen.

Potentially far more serious health problems than FMD itself have been posed by the mass slaughter policy. Because of Bovine Spongiform Encephalopathy (BSE) or “Mad Cow Disease”, only cattle under the age of 30 months can be used for human consumption. Older ones must be incinerated. BSE in cattle is responsible for the development of the fatal brain wasting disease new variant CJD in humans.

Dirk Hazell, head of the Environmental Services Association, explained, “Until the outbreak of foot and mouth disease, cattle carcasses over 30 months old were being sent to prescribed outlets (high temperature incineration). We are extremely concerned as to the known resilience and potential toxicity of the BSE prion [the mutated brain protein thought to be the transmission mechanism for BSE]. The high risk associated with the prion means that much greater caution must be exercised ... It was not considered safe before the outbreak to landfill carcasses of cattle between 30 months and 60 months.”

Agriculture minister Joyce Quin admitted that it was possible small numbers of FMD cattle “may be in the pre-clinical stage of BSE and harbour some of the BSE agent.” The government suddenly ordered farmers to send cattle older than five years for incineration. There have been last minute attempts to dig huge landfill sites or construct open-air pyres. Kerosene has been used to light pyres constructed of coal slag, old tyres and tar-soaked rail sleepers. The resulting smell and smoke have provoked angry local protests. In addition, open air pyres burn less efficiently than industrial incinerators, producing toxic chemicals such as dioxins. Unpublished official figures show pyres are causing more pollution than all Britain's biggest factories.

A Department of Health report issued on April 24 claims there is no risk from dioxin. However, it recognises that asthma sufferers and those living close to pyres could be made ill by irritants such as sulphur dioxide and particles. It recommends that pyres should be situated two to three kilometres from local communities.

This response resulted from the experience at open-air pyres like that at a disused airfield at Hallburn in Cumbria, the area with the greatest number of FMD outbreaks. A half kilometre long pyre was built, capable of burning 20,000 carcasses a week delivered by hundreds of trucks from all over Northern England. For five weeks a huge cloud of black smoke hung over the town of Longtown, one kilometre away. Residents complained of illnesses and tar-like resins covering their houses and gardens.

A similar pyre with ten rows of burning animals was lit on April 22 outside the village of Holsworthy, Devon in south-west England. The area still has the biggest backlog of unburied carcasses. At one time there were nearly 200,000 lying dead in fields, many waiting up to three weeks for disposal. The reason for this lies in part with the Environment Agency, which has abandoned several mass burial sites because of the threat of water pollution. Although there is little threat from the FMD virus, chemicals and bacteria from the rotting carcasses could pollute the water supply.

The Agency says that pollution is “significant where aquifers (water-bearing layers of rocks) are used for abstracting water for public supply or food/drink processing”. In Cumbria there are 140 such public supplies, as well as the several thousand private supplies where the water is usually untreated. Underground sources, once polluted, are notoriously difficult to clean up, hence the Agency normally require a one metre thick layer of clay in registered landfill sites. This is the case at the Ash Moor landfill site in Devon, where enormous burial pits lined with clay are being constructed for 432,000 carcasses. But it will not be ready for two more weeks.

There are no such requirements for smaller burial sites. On the Epynt military range in Wales, where 15,000 sheep were buried in a trench with no lining, there was evidence of blood and other body fluids in nearby monitoring boreholes five days later. There were reports of streams turning white, probably from the lime used to cover the carcasses. Two of the cleanest salmon rivers in Britain, the Usk and Towy were threatened. The Welsh Assembly has now ordered the sheep to be dug up.

There have been similar reports of blood seeping from the on-site burial of 1,500 sheep at Buttington Hall farm in mid Wales.

The course of the epidemic has proved that successive governments have ignored the lessons of Britain's last FMD epidemic in 1967 and more recent warnings that Europe was at high risk from the disease re-emerging. The current epidemic is a new strain of the virus known as type O Pan-Asia. It was first identified in 1990 in northern India and spread slowly towards Europe and South East Asia, appearing in several countries previously unaffected such as Japan and South Korea.

A report into the swine fever epidemic in the Netherlands in 1997, a year after Prime Minister Blair's Labour government came to power, detailed the growing risk of animal epidemics. It recommended increased tracking and testing of animals. These procedures would have been vital today, as many sheep infected by this type of FMD either do not show symptoms or do so only briefly. Incubation can take between two and 21 days, during which time the disease can have spread.

Besides ignoring the Dutch recommendations, the government has cut veterinary services. The crisis has found the government completely unprepared and making policy zigzags at every major turn in face of pressure from competing economic interest groups. It promised a decision on whether or not to use vaccination within 48 hours on March 29, but has still not done so because farming interests say it will take longer for Britain to regain the disease free status needed for export.