Evaluation of Sub-micrometer-Sized Particles Generated from a Diesel Locomotive and Jackleg Drilling in an Underground Metal Mine

摘要

Concerns have been raised regarding small respirable particles, i.e. sub-micrometer-sized particles, associated with mining activities. This evaluation was designed to investigate the emissions from jackleg drilling and diesel engines and to characterize the nature of emitted particles using gravimetric analysis and number metrics. The mass concentration to which workers are potentially exposed was determined from a 4-h sampling in the vicinity of drilling activities in an underground metal mine; this concentration was found to be lower than 0.6 mg m(-3) of total respirable dust. This mass concentration is low; however, the number concentrations of emitted particles from drilling exceeded 1 x 10(6) particles cm(-3) in areas 7-9 m downwind from the drilling operation. Sub-micrometer-sized particles were also observed in aerosol samples collected using a specialized sampler, and various elements associated with drilling were found among these emitted particles. Finally, the particles in the diesel exhaust were collected, and the exhaust was found to contain nanometer-sized particles.