Abstract

Objectives Occupational coke oven emissions (COEs) have been considered an important health issue. However, there are no conclusive data on human hepatic injury due to COE exposure. The association of COE exposure with liver function was explored and the effects of modification of potential non-occupational factors were assessed.

Methods 705 coke oven workers and 247 referents were investigated. Individual cumulative COE exposure was quantitatively estimated. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transferase, alkaline phosphatase, hepatitis B surface antigen and anti-hepatitis C antibody were measured.

Results Among those with high COE exposure, the adjusted ORs of abnormal ALT and AST were 5.23 (95% CI 2.66 to 10.27) and 1.95 (95% CI 1.18 to 3.52), respectively. Overweight individuals (body mass index (BMI) ≥25 kg/m²) with high COE exposure had elevated risks of abnormal ALT (adjusted OR 23.93, 95% CI 8.73 to 65.62) and AST (adjusted OR 5.18, 95% CI 2.32 to 11.58). Risk of liver damage in hepatitis B virus- or hepatitis C virus-positive individuals with COE exposure was also elevated.

Conclusions Long-term exposure to COE increases the risk of liver dysfunction, which is more prominent among those with higher BMI and hepatitis virus infection. The risk assessment of liver damage associated with COE exposure should take BMI and hepatitis virus infection into consideration.