[Comparison on urinary 1-hydroxypyrene concentrations between coke oven workers and non-occupational exposed...

To compare the urinary 1-hydroxypyrene (1-OHP) concentrations between coke oven workers and non-occupational exposed individuals and to investigate the possible impact factors.

Spot end-of-shift urine samples were collected in 265 coke oven workers and spot morning urine samples in 226 non-occupational exposed individuals. External exposure levels and possible confounding factors were assessed by environmental polycyclic aromatic hydrocarbons (PAH) monitoring and uniform questionnaire, and the urinary 1-OHP concentrations determined by high performance liquid chromatography (HPLC), were used to compare the different urinary 1-OHP levels between different research populations and to explore the effects of several factors such as external exposure levels, smoking habits, alcohol consumptions, age and body mass index (BMI).

The urinary 1-OHP concentrations in coke oven workers were significantly higher than those in non-occupational exposed individuals (13.49, 6.56, 1.38 and 0.35 micromol/mol creatinine for topside workers, side-oven workers, bottom side workers and references, respectively, P < 0.001; the same trends for the percentage of the level over 2.3 micromol/mol creatinine: 94.81%, 84.73%, 35.09% and 0.88%, P < 0.001). The control individuals who smoked over 20 cigarettes per day possessed higher urinary 1-OHP concentrations than the non-smokers (adjusted geometric mean: 0.47 and 0.31 micromol/mol creatinine, respectively, P < 0.05). Alcohol drinking references possessed lower urinary 1-OHP levels than the non-drinkers (adjusted geometric mean: 0.33 and 0.47 micromol/mol creatinine, respectively, P < 0.05).

Coke oven workers should be exposed to a high level of urinary 1-OHP, especially for topside workers and side-oven workers. Background urinary 1-OHP levels in non-occupational exposed individuals should be related to smoking habits and alcohol consumptions.