Respirable Dust and Dust Monitoring in Mines
Miners are particularly vulnerable to prolonged exposure to inhalable and respirable dust as they operate in environments where dust generation is inherent to various mining processes, especially underground. Crushing, drilling, blasting, and other activities release airborne particles such as respirable crystalline silica that, when inhaled, can penetrate deep into the lungs, causing inflammation and scarring over time and potentially causing both short- and long-term respiratory diseases. Extremely fine dust or particulates are not always visible to the naked eye, and controls, personal protective equipment (PPE) and dust monitoring equipment are hence paramount to protecting the health of miners who can be exposed for extended durations while working.
Controls and Safety Measures for Reducing Exposure to High Levels of Dust
Implementation of engineering controls, such as dust suppression systems, ventilation strategies, and the use of enclosed cabins for heavy machinery, plays a crucial role in reducing the generation and dispersion of respirable dust. Adequate PPE, including respiratory masks, further enhances safety, particularly where other controls are insufficient in reducing dust levels below Workplace Exposure Standards (WES). To ensure respiratory protective equipment is providing an adequate seal that will protect the wearer from breathing in hazardous particles, mask fit testing equipment such as the OHD QuantiFit 2 Respirator Fit Tester is required by regulation for all tight fitting respirators.
Gravimetric Sampling for Compliance
When controls have been implemented and dust levels are expected to be below the WES, air quality sampling equipment such as the SKC AirChek Connect Air Sampling Pump is necessary for collecting gravimetric samples. Gravimetric sampling is often used to assess the concentration of particulate matter (PM). These samples are sent to a lab for analysis, and the resulting data can be used to demonstrate compliance. It is important to note that this equipment should not be used to assess dust levels where it is uncertain if exposure is below the standard, as this would mean that workers are being exposed to non-complaint levels while collecting the sample and waiting for analysis.
Safety Advantages of Real-Time Dust Monitoring
Aside from employing gravimetric sampling, real-time dust monitoring can be conducted to bolster safety onsite and in neighbouring communities. Through real-time personal dust monitoring, high exposure alarms can be set to immediately alert onsite personnel to dangerous exposure levels. Additionally, exposure data logs can facilitate the identification of tasks or activities associated with hazardous dust levels, offering a valuable resource for managers to correlate worker actions with peak readings. This data can be instrumental in evaluating the efficacy of dust suppression measures and newly instituted controls. Subsequently, managers can respond proactively by introducing more effective controls, addressing worker behaviour discrepancies, ensuring adherence to best practices, and implementing any other necessary measures.
Alternatively, there are instruments in the market that combine both real-time monitoring and gravimetric sampling into single unit, such as the Nanozen DustCount 9000 Personal Dust Monitor. These instruments allow personnel to take advantage of both technologies without needing to wear multiple instruments or service and manage them separately.
Beyond personal dust monitors, real-time monitoring stations such as the AirMetER Series can also be deployed in strategic locations to continuously monitor dust without the need for personnel to operate equipment onsite. Leveraging cloud-based data portals, site managers can gain remote access to a continuous flow of real-time data from these stations, including alerts for high dust levels at the unit’s location. This makes them ideal for use in perimeter monitoring or at the entrance of an underground mine. In such settings, real-time dust monitoring stations can alert managers when hazardous levels of dust are detected migrating from their site or approaching nearby communities, enabling immediate action to rectify the situation. Aside from providing alerts, this air quality data can also be embedded into a website to provide real-time statistics to staff or the public for transparency, demonstrating safe practice at the site.