Introduction General population studies of air pollution suggest that particles from diesel exhaust emissions are a potential risk factor for cardiovascular disease, while diesel exhaust is also classified as a known human carcinogen. We used data from the Diesel Exhaust in Miners Study to assess excess risk of lung cancer and ischaemic heart disease mortality associated with occupational diesel exhaust exposure.

Methods Analyses were performed in a cohort of non-metal miners in the US (n=12,315), who were exposed to diesel exhaust. We applied the parametric g-formula to assess how hypothetical interventions setting respirable elemental carbon (surrogate for diesel) exposure limits would have impacted lifetime risk of lung cancer, and ischaemic heart disease mortality, while adjusting for time-varying employment status.

Results Lung cancer and ischaemic heart disease mortality risk decreased in association with interventions on respirable elemental carbon, with risk ratios of 0.73 (95% confidence interval CI: 0.44 to 1.07) and 0.86 (95% CI: 0.66 to 1.12) respectively, when comparing an intervention setting respirable elemental carbon exposure to zero to the observed natural course.

Conclusion Our findings suggest excess risk of lung cancer and ischaemic heart disease mortality associated with diesel exhaust exposure in this occupational setting and that interventions on exposure would have resulted in reduced risk for both outcomes.