GPs advised to enquire about silicosis
By Dr Clem Bonney, Geebung Medical Clinic and Dr Graeme Edwards, Consultant Physician in Occupational and Environmental Medicine
Silicosis is an occupational lung disease that is caused by inhaling crystalline silica. Recently there has been a spike in confirmed cases among Australian workers involved in the production and installation of artificial stone benchtops and GPs are being advised to speak to those in the industry about their potential exposure.
Silica is present in sand, some bricks, granite and other materials. Cutting, grinding and polishing dry artificial stone exposes workers to crystalline silica in far higher quantities than those found in natural stone. Installed benchtops present no risk to the general population.
Exposure to the respirable fraction of the silica dust, cumulated over time, can cause several diseases including:
- silicosis (ranging from acute through to accelerated, chronic and complicated)
- activated autoimmune disease
- lung cancer (has only been seen in those who have chronic silicosis)
- occupational COPD
- renal disease.
Symptoms can include:
- most are asymptomatic with only early indices of respiratory dysfunction
- shortness of breath (initially often perceived as trivial in severity)
- increasing sputum production
- weight loss
- chest pain.
These symptoms may develop after exposure to respirable crystalline silica has ceased, although continued exposure hastens the progression of the disease. There is currently no known treatment to arrest the progression of accelerated silicosis, apart from lung transplantation.
The Australasian Faculty of Occupational and Environmental Medicine and the Thoracic Society of Australia and New Zealand recommend that medical practitioners and occupational nurses ask all attending building industry workers about work with artificial stone.
If a patient has been exposed to artificial or engineered stone medical professionals are advised to:
- ask about respiratory symptoms, bearing in mind that in the early stages of the condition the patient will be asymptomatic
- assess the patient using chest x-ray (with ILO classification) and full lung function testing including diffusion capacity DLCO. Spirometry performed in a non-laboratory setting is associated with a significant false negative rate and may falsely reassure you and your patient
- a high resolution CT chest (non-contrast) should also be strongly considered if the patient has worked in this industry for over three years
- if there are any concerns refer to an occupational physician or respiratory physician for further assessment.
The specialist will undertake the risk and exposure assessment by allocating the person to a similar exposure group and assessing their duration and intensity of exposure. This will help qualify the individual’s risk profile when interpreting the results of the CXR, lung function and HRCT findings.