Silica diseases are caused by the inhalation of silica dust. Sandstone has a very high silica content and is prevalent on the east coast of NSW, particularly in the Sydney basis where the excavation of Hawkesbury sandstone is necessary during the course of road construction, tunnel construction or other developments. Such excavation work creates high levels of silica dust. Consequently, labourers and construction workers who work on these projects are at risk of developing silica diseases. Foundry workers can also be exposed to high levels of silica dust during the course of their work, placing them at risk of developing silica diseases. Pottery or ceramic workers are also at risk of developing silica diseases. The diseases caused by the inhalation of silica dust are set out below:
Simple silicosis is caused by the inhalation of silica dust which causes inflammation and scarring in the lungs resulting in nodular lesions forming in the upper lobes of the lungs. In its early stages, it may not cause any symptoms. As time goes on, the worker may develop a cough and shortness of breath on exertion. Simple silicosis tends to result from low level exposures to silica dust over a number of years and does not always progress.
Accelerated silicosis tends to result from very heavy and prolonged exposure to silica dust. It tends to develop earlier and progresses. Symptoms include a chronic cough and severe shortness of breath on exertion.