Silica is one of the most prevalent elements found on earth. Of relevance to occupational health is that it is a component found in natural and engineered stone.  The silica content in natural stone varies from 5% for marble, 20-40% for slate, 25-60% for granite and 70-90% for sandstone. Engineered stone contains 80-95% silica.

Hazardous silica dust is released into the air from drilling, chipping, cutting, grinding, sanding, polishing or crushing and screening natural rock and ore as in granite, sandstone, slate quarries and in mining.  Workers are exposed to hazardous silica dust when products containing silica such as engineered stone, concrete, and masonry are drilled, chipped, cut, ground, sanded, polished or crushed. The perfect storm of silica dust exposure comes when silica is finely ground and becomes a fine airborne dust.

Silica dust exposure has historically been associated with chronic silicosis from exposure to relatively low levels of dust. Chronic silicosis, which develops slowly over decades (10-30 years), may become symptomatic towards the end of the worker’s working life or after retirement.Since early 2000, the use of engineered stone products for kitchen and bathroom benchtops has led to the emergence of accelerated silicosis among workers (in their 30’s, 40’s and 50’s) following work exposures of 5-10 years. 

Silicosis is an occupational lung disease caused by the inhalation of fine silica dust.  It is a progressive disease which can remain asymptomatic for decades. There is no effective treatment even after cessation of exposure. For the above reasons, silica health surveillance has become an increasing matter for employers and workplace regulating bodies.


Changes to your obligations?

As part of an increased silica health surveillance program, workers who are at risk of silica dust exposure may be required to undergo a silica exposure test before starting work, so that a baseline can be established and any changes to the worker’s health after commencing the work can be detected.On 15 January 2021, legislation was passed for low dose CT scan (LDCT) to replace chest X-ray in Western Australia, as the radiological screening test for occupational exposure to silica. You can no longer use chest X-rays for this purpose.  All information related to a worker’s exposure is benchmarked at pre-placement assessments and at regular intervals during their employment and this must be reported to Worksafe WA.

A low dose CT high-resolution chest scan (LDCT) with a dose limit of 1 mSv or less, provides an image quality sufficient to detect silicosis and early changes. No contrast should be used. A LDCT is to be repeated at 2 to 5 yearly intervals depending on the risk exposure of the worker. It is important that radiation exposures are kept as low as possible.


Why choose CCH ?

Health surveillance – including silica health surveillance – is required to be provided by the employer, at no cost, to workers who are at risk of adverse health effects from exposure to a hazardous substance in the workplace.  

Health surveillance must be supervised by a medical practitioner who has been appointed by the employer. The appointed medical practitioner (AMP) must be trained to conduct health surveillance in relation to hazardous substances.

All our Doctors at CCH have been trained to provide health surveillance to the required standard.  Our process is robust and thorough and will ensure you meet your obligations both to your employees and Worksafe WA.

Our process for silica testing is simple:

  1. First you will be assessed by an Occupational Doctor who will collect medical and employment history and complete a physical examination of the respiratory system.
  2. Then a lung function test (spirometry) will measure how well air is moved in and out of your lungs.
  3. Finally, a low dose CT-Scan (where required, based on the interval between assessments and risk exposure of the worker) will be taken to identify any abnormalities.  This is completed at our radiology partner Perth Radiological Clinic (PRC).


For more information, get in touch with us now 



DMIRS WA Health Surveillance – Silica May 2021