JOHANNESBURG - His breathing is laboured, his chest is tight, and he is too weak to work in his garden any more. At the age of 63, former mine worker Wilson Mafolwana wonders if he’ll still be alive when justice is done.

He is among the millions of migrant workers who toiled in South Africa’s gold mines in the apartheid era, building the world’s biggest gold industry – and often sacrificing their health in the process. Breathing clouds of dust, usually without ventilation masks, tens of thousands of miners contracted silicosis and tuberculosis, and many are now dying.

Mr. Mafolwana and 17 other ex-miners with silicosis have launched a test case against the South African unit of Anglo American, one of the world’s biggest mining companies, to seek compensation for their illnesses. But the case has dragged on for seven years, with no decision expected until next year at the earliest.

While the company fights the lawsuit with all its legal and financial resources, four of the 18 former miners have died. Others grow sicker every day.

Death is the constant shadow that haunts the ex-mine workers as they struggle for compensation. In a separate case this year, Thembekile Mankayi won the right to sue his former employer, AngloGold Ashanti, for compensation for the silicosis that he suffered while working underground for 16 years. Tragically, he never witnessed the court victory because he died of lung disease at the age of 53 – less than a week before the ruling. After the ruling, AngloGold said it will continue to argue against his legal claim.

Under apartheid, black migrant labourers usually had the most dangerous jobs in the mines, with little safety equipment. About 25 per cent ended up with silicosis – a much higher percentage than among the white workers. Even their compensation payments were discriminatory, because they were based on earnings, which were much smaller for black workers than for whites.

Thousands of ex-miners have died of respiratory illnesses without treatment or compensation, often because they were too weak to reach a hospital for diagnosis. Activists call it “an unfolding public health disaster.” Less than half of the victims have received compensation, usually just a few thousand dollars or less. The same problem extends across sub-Saharan Africa, where up to 760,000 new cases of tuberculosis annually can be attributed to the mining industry, according to a recent study.

Black mine workers such as Mr. Mankayi “have contributed enormously to this country’s economic wealth and prosperity, at great cost to themselves and to their health,” the South African Constitutional Court said in its decision this year. As a result of its ruling, thousands of mine workers will now proceed with a class-action lawsuit against South African mining companies. Billions of dollars could be at stake.

But the compensation may be for their surviving families, not the workers themselves. In an interview, Mr. Mafolwana was forced to pause often to catch his breath. He worries that he could die before the test case is over.

“Justice has not been done, and some people have already died,” he said. “I could pass on too. My health is deteriorating. When it is rainy or cold, my chest is always tight.”

Mr. Mafolwana first noticed the silicosis symptoms in the late 1980s, when he had trouble breathing, but he could not afford to quit his underground job. Basic health measures, such as distributing masks and using water to suppress the dust, were rarely taken by the employers, he says. He finally left the job in 1994 when he could work no longer.

“I felt something in my chest when I was working, but the company doctor refused to take me out from the underground job,” he said. “It was always dusty. We asked them to please protect us from the dust, but they didn’t give us a mask, except when the inspectors came.”

Anglo American says it is not responsible for the compensation claims because it owned only a minority share in the South African mines where the plaintiffs were working. It says it is “sympathetic” to the plight of the former workers and is working to find a “sustainable solution” so that they can obtain medical treatment and compensation benefits.

One of the workers in the test case, 48-year-old Alpheus Blom, attended the annual meeting of Anglo American in London last year – his first trip outside South Africa. In a statement read to the shareholders by his wife, he described how he contracted silicosis and tuberculosis after 17 years in one of Anglo’s mines. He recalled how the black workers were forced to make their own rudimentary masks by stealing bandages because the mine refused to give masks to them.

“The gold-mining industry knew that thousands of miners were contracting silicosis each year,” he said. “They knew there was too much dust. We should have been able to wash our overalls every night and use showers, to reduce the amount of dust we inhaled. White miners were given access to showers and changing rooms, but black miners were not.”

This year, Mr. Blom wanted to attend the Anglo American annual meeting again, but his health had deteriorated and he was too sick to travel to London.

Tony Davies, a South African medical expert, says the country has known since 1914 that most of its mining deaths are due to silicosis, caused by inhaling particles of quartz.

Silicosis causes scarring of the lungs, impedes breathing and can eventually cause heart failure. Studies in the 1990s showed a “horrendous” rate of silicosis among South African mine workers, he said.

Tuberculosis rates among mine workers in South Africa are hundreds of times higher than in North America, Dr. Davies said. “It’s a massive, massive epidemic.”