Silicosis – the how, what and why

The disease that can potentially affect a wide range of occupations

Key Facts:

    • Silicosis is an incurable and often fatal lung disease caused by breathing dust containing respirable (< 7 microns) fragments of crystalline silica.
    • Silica in concrete, masonry, sandstone, rock, paint, manufactured stone and other abrasives is released by cutting, drilling or blasting.
    • Three types of silicosis:

    Chronic (most common) from 15 years +

    Accelerated, from higher exposure levels and 5-10 years of exposure

    Acute (fatal) from weeks or months of very high exposure. Acute Silicosis can cause very serious health effects and is life threatening

    • As well as being a lung carcinogen, Silica causes renal disease, and other auto-immune diseases like rheumatoid arthritis
    • WHS Regulations (2017) state a PCBU must ensure that no person at the workplace is exposed to a substance or mixture in an airborne concentration that exceeds the exposure standard for the substance or mixture and must reduce exposures so far is reasonably practicable.
    • Workplace Exposure Standard for respirable crystalline silica (RCS) that must not be exceeded is 0.1mg/m3 averaged over 8 hours

    Source: US Centers for Disease Control and Prevention & NSW WHS Safety Regulations 2017 & Safework NSW Crystalline Silica Technical fact sheet

    Why do we need to be concerned?

    Late 2018 the Queensland Government issued an urgent warning to the engineered stone benchtop industry, after it emerged 22 stonemasons had been diagnosed with the incurable disease, silicosis – including six people who were diagnosed as terminal.

    In the ensuing health screenings ordered by the Queensland Government, Brisbane’s Dr Graeme Edwards tested hundreds of stone workers. He believes the health crisis will become worse than asbestosis.
    ‘We’re talking about a major epidemic that we don’t fully appreciate right now – it’s absolutely in a league of its own,’ Dr Edwards said.  ‘this is worse than asbestos, because asbestos affects people at the end of their working life and into retirement, where this Silicosis is affecting young workers, people with dependent children, with wives and a whole working life expectation before them.

    In most cases there were no symptoms, the disease only confirmed upon screening. The youngest person identified with silicosis is a 23-year-old who has worked as a stonemason for six years.

    At least 98 stone QLD workers have been diagnosed with silicosis, but it’s feared that number will grow, with 562 statutory and infringement notices being issued during a four-month crackdown on the QLD stone fabrication industry.

    Exposure – not only stonemasons are at risk

    The Cancer Council says about 587,000 Australian workers were exposed to silica dust while on the job in 2011 and about 5,758 of those are estimated to develop lung cancer in the future as a result of that exposure.

    Many job tasks place workers at risk for inhaling silica dust, including:

    • Using power tools to remove paint or rust
    • Performing abrasive blasting
    • Grinding mortar
    • Crushing, hauling, chipping and drilling concrete or rock
    • Dry-sweeping dust from crushed concrete or rock
    • Finishing plasterboard
    • Construction jobs, such tunnelling, digging and bridge and highway repair
    • Manufacture of glass, ceramics, brick, concrete, tile metals or machinery

    Source: National Institute of Occupational Hygienists USA

    Dr. Robert Cohen is Professor of Medicine and Director of Occupational Lung Disease Feinberg School of Medicine NorthWestern University recently spoke at the Queensland Parliament – Coal Workers’ Pneumoconiosis Select Committee Inquiry.  He says “Silica is probably more dangerous than coalmine dust. Quarriers, tunnellers, metal miners—anyone who is disturbing the earth’s crust and drilling through rock is at risk for quartz and silica exposure. There should be industrial hygiene monitoring of the exposure levels.’

    What can be done?

    The USA has recently lowered safe exposure levels to silica from 0.1 mg/m3 to 0.05 mg/m3 , an 8 hour time weighted average because of the horrendous diseases that occur from silica.

    In Queensland, “dry cutting” engineered stone is banned due to the dangerous level of dust it releases. The Royal Australasian College of Physicians (RACP) wants the technique banned in all states.

    But given that the earth’s crust is 59 percent silica and it is the main constituent of more than 95 percent of known rocks, protecting workers against silicosis needs to go far further than the engineered stone industry.

    Here’s a quick checklist:

    • Have your workers understand the dangers of breathing in crystalline silica dust and avoid working in or near dust whenever possible.
    • Remember: Even if you cannot see dust, your team may still be at risk.
    • Use water spray systems and proper ventilation in confined spaces.
    • If water systems and ventilation are not enough, you must provide respirators specifically designed to protect against crystalline silica.
    • Offer health and lung screenings to employees
    • Thoroughly wash hands before eating or drinking in dusty areas.
    • Rotate Staff to limit the time that they are exposed and locate Silica work away from other works.
    • Don’t clean up using compressed air or by dry sweeping, dust should be removed by an industrial HEPA filter vacuum.
    • Shower and change into clean clothes before leaving work to help prevent contamination of car or home.

    Source: The National Institute for Occupational Safety and Health (NIOSH)

    Your Duty of Care

    NSW Government Work Health and Safety Regulation 2017 have specific rules about airborne contaminants.  Source Part 3.2 Division 7 & 8.

    Ensuring exposure standards for substances and mixtures not exceeded

    • A PCBU must ensure that no person at the workplace is exposed to a substance or mixture in an airborne concentration that exceeds the exposure standard for the substance or mixture.
    • WHS Regulations state that health monitoring must be provided to workers who are continually working with silica dust and there is a significant risk to the workers’ health. Baseline monitoring before starting work and then annually is recommended. Further information is outlined in theAir monitoring airborne contaminant levels fact sheet that can downloaded here.
    • A person conducting a business or undertaking at a workplace must ensure that air monitoring is carried out to determine the airborne concentration of a substance or mixture at the workplace to which an exposure standard applies if:
      1. The person is not certain on reasonable grounds whether or not the airborne concentration of the substance or mixture at the workplace exceeds the relevant exposure standard, or
      2. Monitoring is necessary to determine whether there is a risk to health.
    • A PCBU must ensure that the results of air monitoring carried out under are recorded and kept for 30 years after the date the record is made.
    • A PCBU must ensure that the results of air monitoring carried out are readily accessible to persons at the workplace who may be exposed to the substance or mixture.

    What next?

    If you have any concern that your workers may be exposed to Silica dust, please don’t hesitate to give us a call on 1300 372 436 for a confidential and obligation free discussion about your situation

    Sources:

    www.safetyandhealthmagazine.com/

    Dr. Robert Cohen is Professor of Medicine and Director of Occupational Lung Disease Feinberg School of medicine NorthWestern University

    National Institute of Occupational Hygienists USA

    NSW Govt Work Health and Safety Regulations 2017

    SafeWork NSW Crystalline Silica Technical Fact Sheet

    Safe Work Australia Crystalline Silica Health Monitoring 2013