Abstract

Objectives: This study was conducted to assess external and internal exposure of workers to polycyclic aromatic hydrocarbons (PAH). In this context the analytical and diagnostical reliability of 3-hydroxybenzo[a]pyrene as a biomarker of internal exposure to PAH was established. Methods: Ambient and biological monitoring was carried out at 225 PAH exposed employees of different industries. External exposure was determined by personal air sampling and analysis of the 16 EPA-PAH. Internal exposure was examined by urinary metabolites 3-hydroxybenzo[a]pyrene, 1-hydroxypyrene and monohydroxylated phenanthrenes. Results: At all workplaces, benzo[a]pyrene was detected. Concentrations in the breathing zone of the workers ranged from <LOD up to 44.3 µg/m³. In biological monitoring, urinary 3-hydroxybenzo[a]pyrene was found in median concentrations of 0.8ng/g crea and 95th percentile of 6.7ng/g crea. The results ranged from limit of detection up to 19.5ng/g crea. Only one percent of the analysed samples showed concentrations below the limit of detection (0.05ng/l). Regarding median concentrations, workers in coking plants show lower 3 hydroxybenzo[a]pyrene-concentrations (0.5ng/g crea) than those in refractories (1.1ng/g crea), converter infeed (1.2ng/g crea) and graphite-electrodes production (1.3ng/g crea). Strong correlations of 3-hydroxybenzo[a]pyrene with 1-hydroxypyrene and the sum of hydroxylated phenanthrenes were found for the workplaces converter infeed, coking plants and graphite electrodes (rPearson ranging from 0.618 to 0.867, p<0.001). The poor correlation of benzo[a]pyrene in the air and 3-hydroxybenzo[a]pyrene in urine is most likely caused by routes of uptake other than via air, e.g. dermal uptake. Conclusion: 3-Hydroxybenzo[a]pyrene as metabolite of the carcinogenic benzo[a]pyrene could be shown as a diagnostically specific and sensitive biomarker for determining the internal exposure of workers in different industries. Using this method the estimation of health risks for workers can be fundamentally improved, because the parameter 3-hydroxybenzo[a]pyrene represents the group of carcinogenic PAH. The procedure for analysing 3-hydroxybenzo[a]pyrene is complex, but it works robust and produces reliable results.