A Century of Miners’ Phthisis on the South African Gold Mines. Any End in Sight?

Since its inception in 1886, high rates of occupational lung disease, particularly “miners’ phthisis” (silicosis and/or pulmonary tuberculosis) and accompanying racial disparities have been a feature of the South African gold mining industry. While mortality from silicosis and pulmonary tuberculosis fell among white miners during the first half of the 20th century, there was scanty information on silicosis among migrant black miners, it being widely held that high turnover and relatively short service protected them against silicosis. Data collected for statutory purposes on examinations of black workers showed an incidence of silicosis, with or without accompanying tuberculosis, of the order of 2 to 3 per 1,000 between 1916 and 1947. While these compensation figures had risen to 5 or 6 per 1,000 by the late 1980s, prevalence studies on black miners were lacking. When such studies were eventually done, both independently of and from within the industry, a prevalence of silicosis among longer service workers of the order 20% to 25% emerged using the ILO profusion threshold of 1/1. Commentators have noted that there is no evidence that silica dust concentrations in the South African gold mines have been lowered substantially since the 1930s. The recent findings cited above suggest a rising prevalence of chronic silicosis among black miners, arguably to a level not recorded before in the history of the industry. Part of this rise may be due to historical factors that have served to obscure this burden, but the “stabilization” of the black workforce due to changes in the industry resulting in longer continuous service, is a more likely explanation. Combined with a high prevalence of HIV infection among miners (of the order of 20% to 30%), the pulmonary tuberculosis incidence rate has