Three Decades of Silicosis: Disease Trends at Autopsy in South African Gold Miners

Abstract

BackgroundEliminating silicosis is a priority of the International Labour Organization and the World Health Organization. Prevalence is particularly high in developing countries.ObjectivesWe describe trends in silicosis among South African gold miners who had had an autopsy between 1975 and 2007 and quantify the contributions of age at autopsy and employment duration to these trends.MethodsSouth African miners and ex-miners are eligible for autopsy examination for occupational lung disease, regardless of the clinical cause of death, and the families of deceased mine workers may receive compensation from the government of South Africa. Miners who died from external causes and who had been employed in the gold mines for > 1 year were stratified by population group because of differences in exposure, patterns of employment, and autopsy referral patterns. We extracted data from PATHAUT (Pathology Automation System) and used Stata 10 to estimate trends in relative proportions of silicosis that were standardized for age and employment duration.ResultsThe crude proportion of silicosis for white miners was six times that of black miners in 1975. By 2007, it was 1.5 times higher for black miners. The proportion of miners with silicosis increased from 0.03 to 0.32 for black miners and from 0.18 to 0.22 for white miners. The increase can be explained by increasing age and employment duration for white miners. For black miners, it can be only partly explained by these two factors.ConclusionAs miners continue to age and work for longer periods, the burden of silicosis will continue to rise. South Africa is committed to global efforts to eliminate silicosis by 2030. The autopsy database allows for disease surveillance, which is necessary to monitor the success of this initiative.

Hazards identified and the need for health risk assessment in the South African mining industry

“…A 33-year study has shown no reduction in the proportion of miners coming to autopsy with pathologic evidence of silicosis. 10 In addition to silicosis in gold and platinum mines due to exposure to silica, 11 there is coal workers' pneumoconiosis (CWP) among coal mine workers 12 and asbestosis among workers and individuals who live in areas surrounding asbestos mines. 13 There is also a risk of asbestosis, lung cancer and mesothelioma in diamond mines since asbestos and asbestos-like deposits exist very close to diamond deposits.…”

A century of miners' compensation in South Africa

“…Compensation is payable to qualifying beneficiaries if there is evidence of significant compensable disease irrespective of whether it contributed to death. Unlike the families of black miners dying in service, those of black former miners have infrequently benefited from this autopsy provision-for reasons which include reluctance by next-of-kin to consent, lack of knowledge of the system on the part of both miners and health care professionals, and a shortage of facilities for removal of the organs in rural areas [Roberts, 2009;Nelson et al, 2010].…”

“…One hundred years later, the gold mining industry is struggling with a resurgent wave of silicosis and tuberculosis, mainly in black miners 1 [Ehrlich, 2007;Rees et al, 2009;Nelson et al, 2010], with tuberculosis fuelled further by the HIV epidemic [Corbett et al, 2000;Park et al, 2009]. The industry's recent history is one of decline, with employment peaking in 1988 at 480,000 and falling to 160,000 by 2006 [Harington et al, 2004].…”

Occupational lung disease in the South African mining industry: Research and policy implementation

“…3,4 These social circumstances and stabilization have contributed to serious interrelated epidemics of silicosis (silica dust-induced scarring of the lung), 5 tuberculosis (TB), and HIV infection in miners, in surrounding communities and in labor-sending regions.…”