BSE (Bovine Spongiform Encephalopathy), or Mad Cow Disease, and its human form, nvCJD (New Variant Creutzfeldt-Jacob Disease), are incurable brain disorders.

A theory about how prions are formed suggests that organophosphate pesticides could be partly to blame. Two people have already died defending this theory, apparently at the hands of professional assassins working either for the British government or the chemical industry. So the theory needs to be taken seriously.

BSE first appeared in the UK in 1985. Since then, the disease has affected half of the cow herds in the country. New Variant CJD also first appeared in the UK, ten years later: to date, around 90 people have died from it. Both BSE and CDJ are beginning to spread throughout the rest of Europe; today, 30 European countries have had exports of their cattle banned.

The diseases have the potential to destroy the entire European cattle industry, and kill thousands of people. The death toll from nvCJD is increasing by 35% per year, and the disease has a gestation period of twenty years. Some projections suggest that hundreds of thousands of people could eventually die from it.

Given the huge amount at stake, one might expect that any credible theory would be welcomed. Yet Mark Purdey, a British farmer from Somerset, has suffered constant harassment and has had to support his research from his own pocket. Purdey has a theory which might explain the mystery of why BSE and new variant nvCJD started in the UK, and why they are so much more serious there.

However, since he went public with his ideas, some rather unfortunate things have happened: 1) Both his vet and the lawyer defending his case died in suspicious road accidents. His second lawyer also had a car crash, but survived.

2) When an article about his work appeared in the "Independent", a national British newspaper, his telephone lines were cut. He was therefore unable to take follow up calls from other papers and television stations.

3) His farm house was burnt down just before he was about to move in.

4) His science library was destroyed by a collapsing barn.

5) When he travels around the country to talk about his theory, he is constantly trailed.

Purdey believes that the root cause of BSE is an imbalance of magnesium and copper, exacerbated, in the case of the UK, by the use of a highly toxic pesticide known as phosmet. Phosphet is an organophosphate nerve toxin, originally developed by the Nazis. It is also related to the drug Thalidamide, which causes birth defects.

Phosmet is made by Zeneca, a subdivision of the British chemical giant ICI. A week after the British government first announced the link between BSE and nvCJD, Zeneca sold the patent for phosmet to a PO Box company in Arizona, apparently to avoid potential legal action.

The theory started when Purdey noticed that his cows, unlike those of his neighbours, were not getting BSE. Cows often suffer from a parasitic infection known as warble fly. Since Purdey is an organic farmer, he treated his herd with derris root powder, a natural remedy. Other farmers were using phosmet, which was later made compulsory throughout the UK.

When Purdey bought an infected cow from another herd, he was able to reduce the symptoms of BSE by injecting oxime, which is an antidote to pesticide poisoning. However, officials from MAFF (the Ministry for Agriculture, Fisheries and Food) turned up to kill the cow before the experiment could be completed.

As well as the link to phosmet use, Purdey discovered that brain diseases such as BSE and nvCJD appear in clusters in many places around the world. The link seems to be a lack of copper and an excess of manganese.

For example, in some areas of Colorado and Wyoming, 4-6% of deer and elk suffer from CWD (Chronic Wasting Disease), which is related to nvCJD. These animals live in areas where the soils are very high in manganese. In Slovakia, where the incidence of nvCJD is a thousand times higher than normal, most of the victims live near a glass making plant (where manganese is used) or else down-wind of one of two large ferro-manganese factories.

In the UK, two factors have increased the amount of manganese which cows consume. Until 1988, cows were fed chicken manure. The chicken had been fed manganese to strengthen their eggs, but 98% of it ended up in the manure. In addition, a fungicide rich in manganese was used on crops at that time.

According to Purdey, a lack of copper and an excess of manganese causes proteins in the nervous system of foetal cattle to change into the abnormal prion forms found in BSE and nvCJD. Phosmet facilitates this process by binding to copper, and therefore reducing the amount available to brain tissues.

Recently, Dr David Brown, a chemist at Cambridge University, showed that manganese can replace copper in brain proteins, thereby transforming them into prions. Dr Brown lost his funding, and was not able to continue the research. The BSE crisis started in the UK, and that country still has the highest rate of the disease. Purdey believes that this was because the British government was the only one to enforce systemic phosmet at such a high dose.

Phosmet is used elsewhere, but either on a voluntary basis, or at a much lower dose, or non-systemically.

However, there is a long lag between the peak of phosmet use and the incidence of BSE. Purdey says that this is for two reasons. First, cows are most susceptible to phosmet damage when they are in the womb. Second, phosmet has to reach a certain concentration in the food-chain before it has an effect.

Quite apart from the direct attacks on Mr Purdey, the chemical industry have launched a media campaign to discredit his research. Although MAFF claims that any credible theories for BSE will receive funding, Purdey has received nothing. The effort that the chemical industry has apparently gone to just to discredit Mark Purdey mirrors the experiences of Alice Stewart, the scientist who first showed the link between radiation and cancer.

Scientists who supported her had their cars rammed. Maybe in this case as well, the truth will come out in the end.