Abstract
Mining operations can substantially increase air pollution through multiple processes (e.g., blasting, material handling, haul roads, and non-road equipment), which are difficult to quantify directly. Chemical transport models often underestimate particulate matter smaller than 10 micrometers in diameter (PM10) in mining regions due to incomplete representation of mining-related emission processes. Furthermore, the absence of near-source observational data in these inventories hinders the accuracy of emission estimates and the development of local inventories. This study combines Community Multiscale Air Quality (CMAQ) high-resolution (1 km) air quality modeling with fence-line monitoring records from mining activities to address these shortcomings. To facilitate a more controlled assessment of mining emissions, a mining zone was specifically selected to minimize the impact of other emission sources common in areas such as industries and large urban centers. This mining-dominated environment provides a controlled test of inventory completeness with reduced influence from large urban/industrial sources. Regional emissions were based on Emissions Database for Global Atmospheric Research-Hemispheric Transport of Air Pollution version 2 (EDGAR-HTAP v2), used as the best-available gridded inventory for the 2020 simulations, acknowledging potential changes in practices over time. Default simulations greatly underestimated PM10 concentrations (Normalized Mean Bias, NMB = − 81%). By progressively restricting the evaluation to mining-influenced hours and excluding periods with larger wind-direction/wind-speed errors, it shows that the persistent negative bias is primarily driven by inventory limitations rather than meteorological phase errors. A dry-season (July–August 2020) sensitivity analysis including wind-blown dust led to only marginal improvements, suggesting that material handling, blasting, and non-road vehicles are still important missing sources. Analysis indicates that significant PM10 emissions are generated annually due to missing or underrepresented emission processes in permitted mining operations. These findings underscore the need for process-resolved, site-specific mining inventories that incorporate local operating dynamics and can be integrated into regional air-quality management. More broadly, they highlight that global inventories may require targeted improvements to represent mining regions worldwide.