Silicosis is a type of pneumoconiosis which is particularly associated with dust exposure in gold mines. It is an incurable occupational lung disease caused by prolonged or intensive inhalation of tiny respirable particles of crystalline silica dust.
It is marked by inflammation and scarring in the upper lobes of the lungs. Prior to 1960, acute and accelerated variants of silicosis are said to have been common. Since then, however, the predominant form of silicosis has been ‘chronic’ silicosis, a progressive condition that usually takes at least 10-15 years to develop. 'Uncomplicated' chronic silicosis ranges from mildly symptomatic to severe. ‘Complicated’ silicosis arises where a person who has silicosis develops a further condition or ‘complication’. The most common forms of complicated silicosis are:
- ‘progressive massive fibrosis’, where silicotic nodules in the lung coalesce into massive areas of fibrosis. This occurs in approximately 5% of silicosis cases and is an extremely serious and often fatal condition;
- silico-tuberculosis, where a silicosis sufferer, whose risk of contracting tuberculosis (TB) has been significantly increased by the presence of silicosis, also contracts TB. Silico-TB is a very serious and frequently fatal condition especially if it is not diagnosed and treated promptly and effectively.
Silicosis and TB
Silicosis suffers are particularly vulnerable to contracting TB. Combined with TB, the consequences of silicosis may be fatal especially if the TB is not treated swiftly and effectively.
Silicosis sufferers have a significantly increased risk of contracting TB and TB is endemic in rural labour-sending areas such as the Eastern Cape and Lesotho. This combination of factors has resulted in miners suffering from silicosis returning from the mines, contracting TB and then infecting members of their families and communities. An eminent South African medical expert describes the situation as a "river of disease flowing out of South African mines".
Miners' risk of contracting silicosis and TB continues for the remainder of their lives after they have left the mines and retired. In rural areas, where medical facilities are limited, TB is frequently not diagnosed or treated until serious permanent lung damage (or even death) has occurred. The situation has been made even worse by the fact that the forms of TB contracted include the drug resistant variants XDR TB and MDR TB.
A 2009 study by Rees and others stated: “Hundreds of thousands of men from rural areas of South Africa and neighbouring countries have come to seek work in the gold mines. They are not immigrants in the usual sense as they work for periods in the mines, go home and then return. This is termed oscillating or circular migration. Today we have serious interrelated epidemics of silicosis, tuberculosis and HIV infection in the gold mining industry.”
The study concluded that: “The failure to control dust and tuberculosis has resulted in serious consequences decades later. The economic and political migrant labour system provided the foundations for the epidemics seen in South Africa today”.
Silicosis and asbestosis
Striking parallels can be drawn between silicosis and asbestosis. Asbestosis is an occupational lung disease that is caused by the inhalation of asbestos fibres. Like silicosis it occurs with high intensity or long term exposure to asbestos. Similarly it may take many years for the symptoms of asbestosis to develop.
For over a century both the gold mining and asbestos industries have known full well of the association between dust and lung diseases and of the preventative dust control measures required to minimise the risk of these diseases. However, both industries focused on maximising profit at the expense of the workers' health, in the process of causing lung disease on an epidemic scale. However, whereas the asbestos industry paid dearly, financially for its neglect, the gold mining industry has to-date escaped largely scot-free.