The air pollution related health hazards have been a major public health issue for a long time. As an important source of air pollution, diesel exhaust (DE) exposure associates with serious adverse health outcomes. Apart from the exposure in general population, extensive occupational DE exposure populations are reported in many industries, such as transportation, mining, shipping, and construction. Therefore, the studies for internal exposure levels, biomarkers, and toxic mechanisms of DE in occupational population are critical for protecting human from DE-posed health hazards. This special column published some novel findings involving DE exposure (internal & external exposure level), multiple biological effects, toxicity mechanisms, key molecular events, and crucial biomarkers. These studies will provide scientific data for controlling DE associated occupational health hazards, formulating effective DE pollution control strategies, and provide a new scientific perspective and evidence for health risk assessment and prevention.