Disease from the fibres of asbestos are well reported in the building game, but another material is bringing silicosis back into the dust disease fold, writes Deborah Andrich.

Lung diseases from asbestos fibres have been well reported for many years and resulted in the product being phased out in 1989 and a complete ban in 2003. One major supplier of asbestos products is still paying compensation claims as recently as May this year and will be long into the future.

Another dust-borne lung disease, ‘black lung’ or coal miners’ pneumoconiosis has come to the fore for Queensland miners who have had long exposure to coal dust. Other sources of black lung disease can be from manufacturing graphite and man-made carbon-based products.

A recent NSW parliamentary inquiry into dust diseases has revealed an unsettling resurgence of silicosis – a lung disease caused by exposure to crystalline silica. For the building industry, a source of crystalline silica is manufactured stone, such as those used for kitchen and bathroom benchtops.

What is of major concern to the medical profession is that this disease, last seen with any prevalence in the 1940s and 1950s, has become prevalent once more in the past five years.

A SafeWork Australia survey conducted between 2011 and 2013 of construction workers exposed to carcinogens (cancer causing substances), revealed that after solar UV radiation and tobacco smoke, probable exposure to crystalline silica was the third biggest risk, coming in at 38%. In the main, the primary tasks associated with crystalline silica were identified as mixing concrete or cement. The survey report makes no mention of manufactured stone products as a source of crystalline silica.

Most manufactured stone is a composite of more than 90% crushed quartz (the source of the silica) bonded with a polyester resin. Cutting, sanding and shaping the stone creates clouds of fi ne dust, which if inhaled, can lead to silicosis.

The use of the product has taken an upswing in recent years with the trend for modern kitchens to have stone benchtops. Using natural stones such as granite have limited colour options, can be porous and if join seams are needed, trickier to seal, hence the preference for many to use manufactured stone for its durability.

WHAT IS SILICOSIS?
Breathing in silica dust can cause inflammation of the lungs, which results in scarring and calcification, eventually leading to reduced lung capacity. It usually becomes evident after prolonged exposure to respirable crystalline silica (the dust particles). Early symptoms include shortness of breath, a dry cough and a general feeling of being unwell. As the disease progresses, the symptoms become worse. There are no effective cures for the disease and treatment is mostly aimed at relieving symptoms and preventing infections such as tuberculosis.

According to data collected by icare Dust Diseases Care an average of nine cases of silicosis each year has been officially reported under the NSW Dust Diseases Scheme since 2011/2012. It should be noted that the figures are limited to those who have applied for compensation under the scheme.

Given that the time frame from exposure to diagnosis can be many years, detecting an increase in the disease  can take time. The Medical Journal of Australia recently published an article headed up by Dr Anthony Johnson discussing cases of silicosis in Sydney hospitals.

“In almost all reported cases, there was little adherence to basic protection measures, such as provision of appropriate ventilation systems and use of personal protective equipment,” the report says.

“Our case reaffirms the need for vigorous enforcement of dust reduction regulations, particularly in the growing industry of engineered stone products. Benchtop stonemasonry is a potentially dangerous occupation, and medical practitioners should have a heightened awareness of this newly described occupational hazard,” says Dr Johnson.

MINIMISE THE RISK
In a statement from SafeWork NSW spokesperson, repeated and prolonged exposure to respirable crystalline silica can cause permanent injury and lead to serious lung disease such as silicosis.

“Exposure to potentially harmful levels of crystalline silica is typically a hazard for workers in specific occupations. These include mining, quarrying, foundries, abrasive blasting, construction and demolition, as well as the manufacture of stone, clay and glass products,” says the spokesperson.

“Within the workplace, exposure can be reduced by changes in work practices, engineering controls to achieve dust containment and suppression, and the use of suitable personal protection equipment.”

Recommendations from SafeWork NSW on how to eliminate or minimise exposure at the time included sprays to dampen dust, appropriate ventilation and RPE (respiratory protective equipment) are:

Water suppression
– Water suppression techniques enable damping down of dust at the source of emission. Water is directed onto a tool cutting point via the covering shroud or hood. Water flow is controlled, allowing management of the water volume supplied in line with manufacturer’s instructions. In stone masonry, stone is pre-soaked to minimise dust creation and apply running water to the process via on-tool suppression to further reduce exposures.

Dust extraction – Local exhaust ventilation (LEV)
– If it is a dry manufacturing process, enclose dusty work in a down draught or cross draught booth so that the dust laden air is drawn away from the work area.
– Use ’on-tool’ LEV with power tools such as grinders. A vacuum source is attached to the shroud to remove dust generated by the grinder at the source of emission.

Personal Protective Equipment (PPE)
– Respiratory protective equipment (RPE) may be required if engineering controls do not effectively reduce or capture the dust. Wearers must be face fi t tested to ensure the RPE affords each individual the anticipated level of protection. Remember that filtering face-piece or half-mask respirators give little or no protection to men with beards and that even a minor growth of stubble can severely reduce the effectiveness of RPE.

Water suppression and LEV systems may not eliminate all silica dust. Residual dust concentrations are variable and unpredictable, so respiratory protective equipment (RPE) may be necessary. Do not use compressed air hosing or sweep areas where slurry from wet processes has dried as this will generate dust. Using a High Efficiency Particulate Air (HEPA) vacuum cleaner is also recommended.

Air monitoring for workers’ exposure to respirable crystalline silica (RCS) may be done to check if workers are exposed to dust levels above the Australian Workplace Exposure Standards. This will also enable the workplace to check if their dust controls are effective.

If workers are at significant risk of exposure to RCS, health monitoring must be undertaken regularly for early detection of disease. It must be done under the supervision of an appropriate medical doctor and includes lung function tests and chest x-rays.

Information, training, instruction and supervision
This must be provided not only to workers but to other persons at the workplace such as visitors. It must be provided in such a way that it is easily understood. The amount of detail and extent of training will depend on the nature of the hazards and the complexity of the work procedures and control measures required to minimise the risks.

Information, training and instruction should include the following:

– the nature of the hazardous chemicals involved and the risks to the worker.

– the control measures implemented, how to use and maintain them correctly.

– regularly check that control measures continue to be eff ective.

– the arrangements in place to deal with emergencies, including evacuation procedures, containing and cleaning up spills and fi rst aid instructions.

– the selection, use, maintenance and storage of any PPE required to control risks and the limitations of the PPE.

– any health monitoring which may be required and the worker’s rights and obligations.

– the labelling of containers of hazardous chemicals, the information that each part of the label provides and why the information is being provided.

– the availability of SDS for all hazardous chemicals, how to access the SDS, and the information that each part of the SDS provides.

– the work practices and procedures to be followed in the use, handling, processing, storage, transportation, cleaning up and disposal of hazardous chemicals.

– facilities for washing and changing should be available on site and workers should wash their hands before eating, drinking, smoking and going to the toilet. Eating, drinking and smoking should take place away from the work area.

Records of training provided to workers should be kept, documenting who was trained, when and on what.

SEEKING SUPPORT
The state government work health and safety and workers compensation regulators of New South Wales and Queensland give extensive information on health and safety risks of exposure and workers compensation and support for those diagnosed with silicosis. Other states and territories don’t single out silicosis, but do give information on asbestosis which is a good starting point.

The icare Dust Diseases Care program provides a mobile respiratory testing service to visit the workplace. The examination consists of a lung function test by a respiratory scientist, a medical examination by a doctor and if required, an x-ray report by a radiologist. The results are returned to iCare Dust Diseases Care to be analysed by a respiratory physician. A report is provided to the worker and the employer notified if any workplace injury is identified. Employers in NSW must notify the work health and safety regulator.

Once the diagnosis is confirmed, workers can access compensation under the Dust Diseases Care scheme if they were exposed to hazardous dust while working in NSW.

For workers in other states and territories, starting with the local work cover provider is the best starting point to see if a claim for compensation can be lodged.