Assessment of occupational exposure to PAH in coke-oven of Taranto steel plant through biological monitoring

OBJECTIVE: This study aims at evaluating the occupational exposure to polycyclic aromatic hydrocarbons (PAH) through biological monitoring and at investigating the influence of selected genetic polymorphisms on the levels of internal dose biomarker. DESIGN: A cross-sectional study has been conducted on the basis of biological measurements in order to evaluate the levels of PAH exposure. SETTING: PAH exposure assessment has been carried out in a coke-oven of one of the largest European steel plants (ILVA, Taranto), in the context of the program of medical surveillance carried in collaboration with the ILVA Occupational Health Service. PARTICIPANTS: 355 coke-oven workers exposed to PAH were enrolled from the 3 batteries of the coke oven plant. Maintenance workers and industrial cleaners were included. MAIN OUTCOME MEASURES: The measurement of urinary levels of 1-hydroxypyrene (1-OHP) as biomarker of internal dose has been carried out, as well as the evaluation of metabolic polymorphisms of the cytochrome P450 1A1 (CYP1A1), glutathione S-transferases mu (GSTM1) and theta (GSTT1) as biomarkers of susceptibility. RESULTS: The median value of urinary 1-OHP was 1,05 microMol/Molcreat. The difference between the groups was statistically significant, with the highest value observed in the maintenance group (median 1,71, range 0,06-14,69 microMol/Molcreat). It is remarkable that 25% of the workers exceeded the proposed benchmark guideline value of2,3 microMol/Molcreat. No statistical difference was found in relation to smoking habits. Workers with GSTT1 null genotype had higher 1-OHP levels than those with wild type (p = 0,06). CONCLUSIONS: The levels of biomarker of internal dose reflect a critical exposure to PAH in the coke-oven plant. Further observations are needed to better investigate the role of GSTT1 on the 1-OHP levels.