Estimation of quantitative levels of diesel exhaust exposure and the health impact in the contemporary Australian mining industry

Working in the mining industry is characterized by exposure to diesel exhaust (a human carcinogen) due to the wide use of heavy diesel machinery. Quantitative levels of exposure to diesel exhaust expressed by elemental carbon (EC) in the contemporary mining industry were assessed and the excess risk of lung cancer that may result from those levels was examined. Personal EC measurements were available for 146 different jobs at 124 mine sites. The mean estimated EC exposure level for surface occupations in 2011 was 14 mg/m³ for 12-hr shifts. Levels for underground occupation groups ranged from 18 to 44 mg/m³. Underground diesel loader operators had the highest exposed specific job of 59 mg/m³. A lifetime career (45 yr) as a surface worker or underground miner experiencing exposure levels as estimated for 2011 was associated with 5.5 and 38 extra lung cancer deaths per 1000 males respectively. The estimated excess numbers of lung cancer deaths associated with these exposures support the need for implementation of stringent occupational exposure limits for diesel exhaust.