Association between diesel engine exhaust exposure and lung function in Australian gold miners

Previous studies have reported that miners (and other workers) exposed to high levels of diesel engine exhaust (DEE) have an increased risk of lung function decline. The main objective of this study was to evaluate associations between exposure to different components associated with DEE in relation to lung function across a 12-h working shift. Eighty underground gold miners and twenty surface miners completed spirometry and questionnaires at the beginning and end of their 12 h work shift. Personal exposure to elemental carbon (EC), volatile organic compounds (VOCs), nitrogen dioxide (NO₂), particle size and particle number were monitored during their shift. Multiple regression models were used to examine the associations between DEE and lung function, adjusting for a range of covariates. Underground miners were exposed to higher levels of EC, VOCs, NO₂, and particle number and larger mean particle size than surface miners. Cross-shift reduction in Z-score value of FEV₁/FVC in underground miners was statistically significantly greater than those of surface miners. The cross-shift change in Z-score value of FEV₁/FVC was associated with exposure to higher concentration of EC and particle number, but not with VOCs, NO₂ and particle size. Occupational exposure to diesel engine exhaust in current Australian gold mines is substantial. Exposures were higher in underground miners and had a negative association with their lung function over a single 12-h shift.