Diesel particulate matter and polynuclear aromatic hydrocarbon exposure of diesel vehicle operators in small to medium sized underground coal mines

Abstract

Limited data is currently available for diesel particulate matter (DPM) and polynuclear aromatic hydrocarbon (PAH) exposure in underground coal mines in South Africa. The lack of regulatory exposure limits for DPM and PAH in South Africa makes it difficult for the mining industry to evaluate concerned exposure results effectively. The purpose of this study was to determine load haul dump (LHD) vehicle operator exposure to DPM and PAH in four small to medium sized coal mines. Exposures were measured against international standards which could appropriately be implemented in South Africa. The National Institute for Occupational Safety and Health (NIOSH) method 5040 was used to measure exposure for DPM using submicron elemental carbon as surrogate. NIOSH method 5515 was used to measure exposure towards seventeen PAH compounds. Exposure results for DPM were far below the available exposure limit. The use of two LHD vehicles underground showed results that were 2.6 times higher than when one LHD vehicle was used. Exposure results for PAH showed values below laboratory detection limits. The TC/EC values for the four coal mines indicated that the Mine Safety and Health Administration (MSHA) TC/EC value of 1.3 is not suitable for South African coal mines if the MSHA standards for DPM were to be adopted in South Africa. The findings of this study are consistent with another local study conducted in 2008. To conclude, this study emphasized the urgency to establish regulatory exposure limits for DPM and PAH.