Despite a century of surveillance of silicosis and tuberculosis in the South African gold mining industry, black gold miners were afflicted with a triple epidemic of silicosis, tuberculosis and HIV at the turn of the 21 st century. Fertile ground for this new co-epidemic was provided by a migrant labour system that linked rural areas in South Africa and surrounding countries with the gold mining industry. A surge in the employment of miners and the stabilisation of employment contracts from the 1970s shifted the cumulative service curve, and hence silica exposure, upwards. Despite the availability of treatment for tuberculosis, elevated rates of tuberculosis had persisted in the industry, while the known relationship between silica and tuberculosis had faded from memory. The arrival of HIV, another cofactor for tuberculosis, in the 1980s found a large population of men living in single sex accommodation far from their families.
Understanding of this co-epidemic was also limited by the migrant labour system, which had resulted in two subpopulations numbering in the millions in dynamic association with each other. The first were those employed and thus under radiological, clinical and post-mortem surveillance for lung disease, and subject to health selection into and out of the industry. The other were ex-miners, dispersed through remote rural areas with poorly developed economies and health services, to which the burden of mining related lung disease was shifted and whose health experience remained hidden. The Southern African experience of silicosis and tuberculosis and related disorders holds lessons for other countries with active and growing extractive industries. More generally it should also direct our attention to areas of the world dependent on large number of migrant workers employed under harsh conditions, whose work related ill health is ‘externalised’ in various ways. Occupational health needs to regain its public health perspective.