Limiting dust generation, controlling dust liberation at source, monitoring workers’ exposure and ensuring the availability and provision of personal protective equipment (PPE) make up the comprehensive efforts to address dust as an occupational hazard.
Silicosis is a type of occupational lung disease caused by the inhalation of free respirable crystalline silica dust.
Silica is the second most common mineral in the earth’s crust. It is a major component of sand, rock and mineral ores like quartz. Silica dust is present in many industries, including mines and quarries where quartz concentrations are high, as is the case in many deep-level gold mines in South Africa. Multiple mining processes can generate crystalline silica dust such as blasting, drilling and the handling and transporting of rock containing quartz.
Types of Silicosis
If inhaled, crystalline silica dust may cause a fibrotic reaction (or scarring) in the lung, which results in a restriction of lung elasticity. Patients can be diagnosed with one of three types of silicosis depending on the disease’s severity, onset and progression:
- Simple chronic silicosis is caused by long-term exposure (more than 20 years) to low amounts of silica dust, which can cause areas of swelling in the lungs and chest lymph nodes and cause difficulty breathing;
- Accelerated silicosis is caused by exposure to larger amounts of silica dust over a shorter period of time (5 to 15 years). Swelling in the lungs and associated symptoms occur faster than in simple chronic silicosis;
- Acute silicosis is caused by short-term exposure to high concentrations of silica dust. The lungs can become inflamed and can fill with fluid, which causes severe shortness of breath and low blood oxygen levels;
Silica dust exposure in high concentrations can lead to silicosis within a year, but 10 to 15 years typically pass before symptoms begin to manifest in most victims. Medical monitoring and treatment may include regular x-rays and lung function tests; tests for pulmonary tuberculosis and treatment; immunisation against influenza and pneumococcal pneumonia; and antibiotic treatment for lung infection.
Silicosis is an irreversible condition and has no cure, although there are treatment options available to help ease symptoms and related complications.
There have been significant improvements in dust management underground at gold mines, which has reduced the incidence of silicosis diagnoses over the years, according to DMRE statistics. According to Minister Gwede Mantashe’s latest statement, the number of silicosis cases decreased by 28% from 652 cases in 2017 to 465 cases in 2018 https://www.gov.za/speeches/2019-mine-heatlh-and-safety-statistics-24-jan-2020-0000. The working group companies that negotiated the settlement issued this fact sheet on the subject a few years ago https://www.oldcollab.co.za/component/jdownloads/send/4-2016/3-getting-dust-under-control.
- Tuberculosis (TB)
Tuberculosis (TB) is an infectious disease caused by the bacterium Mycobacterium tuberculosis. TB is contracted by breathing in these bacteria droplets. It is usually spread from person-to-person through the air when a person with pulmonary or laryngeal TB coughs, sneezes or talks.
While TB is not highly infectious, unfavourable socio-economic conditions are among the key risk factors for TB. Another factor that is linked to the high incidence and spread of TB is HIV, people with suppressed immunity are more likely to develop active TB.
There are many ways to treat TB, all of which are supplied free of charge to patients by public health or mine clinics. Once diagnosed, regular treatment is necessary and the patient must continue with the treatment for as long as the doctor, nurse or clinic advises.
The effective treatment of TB is a long process, with new patients having to undergo at least six months of treatment. Patients contracting TB for the second time need to be treated for at least eight months.
TB patients must take the full course of medication even when they start to feel better. If they stop taking their medicine before the course is finished, they run the risk of becoming re-infected.
Many mining companies, including all those party to the settlement agreement, provide comprehensive TB screening and treatment for employees. In addition, all settlement companies are party to wage agreements that allow for up to six months fully paid annual sick leave for employees requiring TB treatment. The ODMWA fund further provides compensation for loss of income for employees undergoing TB treatment.