Dust dangers

Dubbed the ‘new asbestos’, respirable crystalline silica is responsible for an alarming spike in chronic and acute lung disorders. Evidence now suggests that silica’s impact will far overshadow asbestos unless appropriate workplace measures are employed… and quickly.

Crystalline silica, or silicone dioxide (SiO₂), is a naturally occurring mineral found in sand, stone, concrete and mortar. It is found in a wide range of products including glass, ceramics, bricks, plastics and artificial stone composites used in kitchen and bathroom benchtops.

Exposure risks

When materials containing SiO₂ are processed — by cutting, drilling, crushing, sawing, polishing or grinding — minute dust particles are created. The small particle size makes it easy to unknowingly inhale, allowing penetration deep into the lungs. Exposed workers can develop the following serious diseases and conditions:

• Chronic obstructive pulmonary disease (COPD) including emphysema and chronic bronchitis
• Kidney damage
• Lung cancer
• Scleroderma — a connective tissue disease
• Silicosis.
   

Silicosis is an incurable and often fatal lung disease. According to Safe Work Australia (SWA), it is further classified into acute, accelerated and chronic forms.

Acute conditions develop after short exposure to very high levels of dust. Within weeks or years, sufferers experience severe inflammation and an outpouring of protein into the lung.

Accelerated silicosis develops after high-level exposures of between three and 10 years; patients incur the inflammation and protein conditions along with development of fibrotic nodules or lung tissue scarring.

In chronic cases (long-term, low-level exposure), individuals experience shortness of breath and develop nodules which can include progressive massive fibrosis (aggregation of nodules).

Susceptible activities and industries

Workers across a range of industries and occupations may be exposed. Some of the more at-risk activities and environments include:

• cutting, grinding, jack hammering, scabbling or chiselling concrete or masonry
• brick cutting and chasing
• brick making, glass making or stonework
• cutting and working with manufactured stone or stone composites
• mining, excavation and blasting
• building, construction and demolition
• foundry or casting work
• roadbuilding
• cleaning dust and debris created by any of these activities.

Worse than asbestos

Silica dust has been on the health radar for a number of years, with the Cancer Council reporting that over 500,000 workers were exposed in 2011. It is estimated that 5758 of those workers will develop lung cancer as a direct result.

An increase in silicosis cases put health professionals on alert but, according to the Thoracic Society of Australia and New Zealand (TSANZ), alarm bells started ringing when the link between stone benchtop fabrication and silicosis was made clear in September 2018.

In February this year, 98 silicosis cases were confirmed in workers from Queensland’s stone manufacturing industry, 15 of whom were deemed terminal. This report followed a state government-ordered industry audit, demanded after a ‘handful’ of silicosis cases presented across the state. Eight hundred stonemasons throughout Queensland have now been referred for health screening.

The sheer scale of the problem has healthcare workers worried, according to an ABC News report, with Australia effectively only capable of accommodating around 200 lung transplant cases per year — not the additional hundreds that will ensue if the numbers play out as expected.

As a result, prior to the federal election the federal government pledged $5 million to establish a National Dust Diseases Taskforce to develop a national approach for the prevention, early identification, control and management of dust diseases in Australia. The funding was also earmarked to establish a National Dust Diseases Register, and to commission new research to support understanding, prevention and treatment of preventable occupational lung diseases.

Employer responsibilities

The current workplace exposure standard for crystalline silica dictates the level that must not be exceeded as 0.1 mg/m³ (eight-hour, time-weighted average). SWA has prioritised a reassessment of this limit as part of a workplace exposure standards review. Now in the public comment phase, more information is available at engage.swa.gov.au/workplace-exposure-standards-review.

PCBUs are required to provide health monitoring for workers exposed to crystalline silica. The SWA website provides extensive information on monitoring requirements.

The Queensland audit uncovered more than 550 breaches relating to workplace practices and provision of suitable PPE. Ten PCBUs were also fined for failing to comply with improvement notices. Thirty-six-year-old Anthony White lost his battle with silicosis in March, after being diagnosed late 2017. White had campaigned to raise awareness of the disease, which is entirely preventable when appropriate controls and monitoring are in place.

To learn more about prevention of silica dust-related harm, including state-specific information, visit the SWA website: www.safeworkaustralia.gov.au/silica.

Image credit: ©stock.adobe.com/au/evgeny