1 Implementation of low-cost sensors in open-cut mining: qualitative assessment of workplace exposure to improve emissions management and reduce risk

Introduction Air quality and workplace exposure are both important considerations in open-cut mining. Regulation typically involves a few expensive reference monitors located at the boundary, assessing hourly and daily concentrations while workplace exposure is assessed once or twice a year. Controlling associated environmental and health risks is typically instigated by subjective operator judgement. Low-cost, portable sensors can supplement these methods to increase both spatial and temporal resolution at a fraction of the cost. Methodology Bespoke low-cost autonomous units were built. The units are solar powered with battery backup and can be deployed in minutes. Each unit samples, averages and sends data to a gateway with the data visualised on an online dashboard. More than a dozen sensors were deployed, and particulate matter data collected from different areas of the mine, over a period of four months. Results Easy installation and quick sampling rate enabled assessment of instantaneous dust generation, in close vicinity to mining activity. Different areas showed periods of similar but also varying particulate matter concentrations, in some instances more than four times difference when averaged over two weeks and more than ten times when considering short-term, five-minute data. Conclusions A real-time system to supplement existing boundary and personal particulate matter monitors is demonstrated to work. The network of sensors can lead to more data-driven decision making with minimised subjectivity and can be integrated into a dust management and action plan that can reduce operational downtime due to regulatory exceedance and occupational risk.