Polycyclic aromatic hydrocarbons (PAHs) are hydrocarbon compounds which originate from incomplete combustion. In humans, PAHs are bioactivated to reactive metabolites which can bind covalently to DNA and subsequently initiate mutation and carcinogenesis. The measurement of PAHs exposure may be used as an index to classify a cancer risk group. The purpose of the present study was to measure the level of urinary 1-hydroxypyrene, a metabolite of PAHs, in subjects exposed to automobile exhaust fumes compared to non-exposed subjects. A urine sample was collected from each individual subject after the end of a working day and quantitated for 1-hydroxypyrene and creatinine by HPLC and spectrophotometric method, respectively. The results showed that average urinary 1-hydroxypyrene level in exposed subjects was significantly higher than non-exposed subjects (mean + SD of 0.0035 + 0.0032 and 0.0011 + 0.0010 μmol/l, respectively; P = 0.000). Average urinary creatinine level in exposed subjects was also significantly higher than non-exposed subjects (mean + SD of 0.01 + 0.005 and 0.008 + 0.006 mol/l, respectively; P = 0.040). The ratio of urinary 1-hydroxypyrene/mol creatinine level, of the exposed subjects was significantly higher than that of the non-exposed subjects (mean + SD of 0.37 + 0.28 and 0.19 + 0.22 μmol/mol creatinine, respectively; P = 0.002). Conclusion: Automobile exhaust fume exposed subjects have a higher risk to be exposed to PAHs than the non-exposed subjects. Urinary 1-hydroxypyrene level can be used as an index for an exposure of PAHs which have originated from automobile exhaust fumes and other sources as well.

Keywords: Polycyclic aromatic hydrocarbons, 1-Hydroxypyrene