Nikolai Burmistrov still speaks with weary bitterness about the escape of anthrax bacteria from a Soviet military compound, which killed 62 people in the city of Yekaterinburg in the Urals 21 years ago.

Nikolai Burmistrov still speaks with weary bitterness about the escape of anthrax bacteria from a Soviet military compound, which killed 62 people in the city of Yekaterinburg in the Urals 21 years ago.

"People died and died," says Mr Burmistrov, a heavy-set middle-aged man, who was working in a ceramics plant in the path of the poisonous plume blown by the south-east wind through the city.

That was on 2 April 1979, and for years the Soviet authorities claimed the anthrax outbreak was the result of people eating contaminated meat. "We never believed it," says Mr Burmistrov. "In a situation like, that ordinary people catch on fast. We knew lots of people who had eaten the meat did not get anthrax. After a few days, we guessed it must have come from the Compound 19."

In the weeks after the anthrax leaked from the bacteriological warfare laboratory in Compound 19, a heavily guarded area behind long grey walls, 22 workers in and around Mr Burmistrov's ceramics factory died of anthrax. "We weren't even allowed to go to the funerals," he says.

The local medical authorities, in Yekaterinburg, then called Sverdlovsk, responded to the rising death toll by an immediate vaccination campaign. For Mr Burmistrov, what happened next has poisoned his life for more than two decades.

Because of the danger of a reaction to the heavy-duty vaccine, young children, old people and pregnant women should not have had the injections.

Mr Burmistrov's wife had just given birth to a son they had called Anton when the anthrax escaped. She had the vaccine as she was weaning him. "We had three injections in three days," he says. "We were not told about the side-effects. When Anton was 18 months old he started to have slight tremors.

"We sent him to hospital but it did no good. The doctors finally told us he has a rare form of epilepsy. Now he is 21 years old but he can only speak a few words and he cannot work."

In one respect, Mr Burmistrov was lucky. Yekaterinburg, the largest city in the Urals, was at the heart of the Soviet arms industry. Since the collapse of the Soviet Union, most of the military factories closed or have little work.

But the ceramics factory, producing tiles and bathroom equipment, and where Mr Burmistrov still works as deputy commercial manager, has prospered, and now employs 1,000 workers.

When we met he was sitting, guarded by a ferocious dog, in a new red-brick house he designed and built himself in a village outside Yekaterinburg. He strongly suspects Anton's epilepsy is the result of his wife breast-feeding him just after she had been vaccinated but he has also heard that Soviet scientists had re-engineered the anthrax for use in bacteriological warfare.

Stories of what had happened in Yekaterinburg began to spread in the West soon after the epidemic, but only in 1991 did Boris Yeltsin, the Communist Party leader in the city at the time of the outbreak, admit "our military development was the cause". By then the KGB security police had confiscated and destroyed most of the essential medical records. The cause was probably faulty filters in the laboratory.

Scientific proof of what happened emerged only through studies by American scientists, whose detective work is chronicled in Jeanne Guillemin's book Anthrax: The Investigation of a Deadly Outbreak, University of California Press, 1999.

The houses and apartments of the 62 admitted victims of the outbreak were scattered all over Chkalovskiy district, in the south of Yekaterinburg. Proof of what really happened came when the scientists plotted on a map where the victims had been working the day the anthrax escaped. From Compound 19, where six people died, they found a narrow corridor of death stretching south-east through the city.

Meteorological records showed there had been a south-easterly wind blowing through Yekaterinburg that day.

The bacteria were blown through another walled military facility, called Compound 32, where 11 people were killed, across a main road, a district of workers' houses and past the ceramics factory. Then it drifted, still south-easterly, into countryside, causing anthrax in animals in a line of six villages before dissipating into the air.

Compound 19 still exists,behind elaborate, ornamental, electrically operated metal gates, but the rest of the outer-perimeter wall, topped with barbed-wire, is ruinous in places. One red-brick building inside the compound has half-fallen down and has weeds growing out of its roof.

The only memorials to the anthrax victims of Yekaterinburg are their graves where they were buried in metal coffins, carried by policemen, in a separate plot beneath the birch and pine trees in Vostochniy cemetery.

Jeanne Guillemin, who spent many years trying to discover how they died before writing her book, cannot forget the visible memories of the victims, the photographs of the dead, attached, as in all Russian cemeteries, to the gravestones, showing faces, smiling and sad, a certain haircut, a thin tie or a flowered shawl.