In this photo, former Lesotho gold miner Moteaphala Molapho, 73, sits in a district office in Semongkong, 75 miles east of the capital Maseru, Jan. 12, 2011. Reuters

The livelihoods of thousands of former gold miners with painful, chronic and fatal lung diseases are at stake as what’s been deemed the “trial of the decade” opened Monday in Johannesburg. Ex-miners -- whose careers began as early as the 1950s -- are suing 32 gold-mining companies, including some of the world’s largest, like AngloGold Ashanti and Gold Fields, for failing to adopt proper safety measures.

The legal challenge threatens to send shockwaves across the mining industry, an economic and political powerhouse in a nation that harbors half of the world’s known gold resources. Studies suggest nearly a quarter of former gold miners in South Africa may have silicosis, an incurable and deadly lung disease caused by the inhalation of crushed sand particles known as silica dust. People suffering from silicosis are at higher risk for tuberculosis.

Occupational health experts have recognized the link between underground mining and silicosis for more than century. And South Africa, once the world’s dominant gold producer, was the first country to compensate silicosis as an occupational disease, in 1912. But workers bringing suit say mining companies regularly neglect to take measures to control silica dust levels.

Lawyers representing miners argued for class-action status Monday. If granted, the designation would allow thousands of former miners to receive compensation under a potential settlement instead of forcing workers to sue for damages individually. One of the law firms representing miners said damages could amount to billions of rand, an amount equivalent to hundreds of millions of dollars.

Gold mining companies oppose class-action status and want a settlement outside court.

“It’s not in anyone’s interest to spend hundreds of millions of rand and 10 to 20 years in court dealing with this issue,” a spokesman for mining companies told South Africa’s state-owned media. “We are hoping to find a fair solution but one that is also sustainable for the industry.”

The Chamber of Mines of South Africa did not immediately respond to a request for comment.

The lawsuit comes at a delicate time for the nation’s gold-mining industry, hamstrung by mounting labor costs and declining global prices. In recent years, output has slid dramatically. The hearings over class certification will proceed until Oct. 23. A decision may not come until next year.

A 2009 study by researchers from Johannesburg's Witswatersrand University and University College, London, estimated 288,000 cases of compensable silicosis in South Africa.