Discovering and Monitoring the Dust Hazards in Mining

Dust is an ever-present threat in mining operations around the globe.

Each state and territory in Australia has its own set of rules and regulations dedicated to managing the risks. And while the human body generally does a great job of stopping large particles from entering the airstream (thanks to our nose), smaller and more harmful particles can still get through. 

One of the most typical particles encountered is quartz or crystalline silica, often found on mine sites, construction jobs and in some manufacturing workplaces. This particular mineral is inherent in various ore bodies, sands, concrete, bricks and engineered stone and represents a severe dust hazard.

Long-term exposure to respirable crystalline silica can cause silicosis, a harsh and sometimes fatal respiratory condition.  

Multiple varieties of asbestiform minerals are also present in mining operations.

These can be encountered during the exploration for and processing of iron ore, base metals and gold. Asbestos is another well-documented dust hazard in mining. While regular mining work tasks like welding, abrasive blasting and grinding can also generate toxic dust and fumes.  Wet ore, concentrates and polymers can reduce dust exposure. But dust inhalation can also happen due to dried spilled material produced from tailings storage, product stockpiles and during product transfer. 

What are the Workplace Exposure Standards Relating to Dust?

While it can differ from state to state, overarching codes of practice in Australia guide workplace dust control. The government organisation Safe Work Australia provides a comprehensive overview of Workplace Exposure Standards (WES).

Here are some of the key takeaways:

1. WES standards are based on the ‘critical effect’ of an airborne contaminant. I.e. the lowest airborne concentration that a person can usually be exposed to before they have an adverse effect.
2. The critical effect can be considered a short-term health effect, like nausea or dizziness, to a long-term negative health outcome, like organ damage or cancer.

Here are the three unique WES values:

• Time Weighted Average (TWA). A substance is given a TWA value if the critical effect on a worker is chronic (long-term) or sub-chronic (medium-term).
  • This represents an 8-hour time-weighted average (a worker’s average airborne exposure in any 8-hour work shift over 40 hours). Most substances in the WES have a TWA.
• Short-Term Exposure Limit (STEL). If the critical effect of a substance is acute (short term), it’s generally given a STEL value, a 15-minute time-weighted average.
• Peak Limitation (peak). If the critical effect of an element is acute and very dangerous, it’s allocated a Peak value.
  • This is the maximum concentration that can be measured over the shortest possible time frame. (Up to a maximum of 15 minutes.)

Guidance on Monitoring the Airborne Dust Hazards in Mining

Airborne particulates must be monitored constantly in mining operations. This ensures that workers and the environment are not exposed to dust over and above the regulated standards.

Air monitoring is required to determine the level of airborne contaminants in a given work setting.

Testing devices can be used for an initial calculation before moving into a monitoring phase to discover if there is a long-term risk to health.

As a tool, air monitoring can help you learn the following:

• How much dust your workers are being exposed to
• Which processes or products are the leading source of exposure, and
• If your current methods of control are working

Summary

Dust hazards in mining are part of the industry. However, strict guidelines and practices are in place to help mitigate the health risks to people and the environment. From understanding the standards to conducting airborne testing and monitoring in your workplace, you can determine your dust hazard level and find a tailored solution that works.

Need help finding a dust suppression solution for your business? Reach out to the team at GRT today and discover your options!

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References:

https://www.safeworkaustralia.gov.au/safety-topic/hazards/occupational-lung-diseases/air-monitoring

https://www.safeworkaustralia.gov.au/safety-topic/managing-health-and-safety/exposure-standards-airborne-contaminants

https://www.commerce.wa.gov.au/worksafe/dust-and-fibres