1-Hydroxypyrene as a biomarker of PAH exposure among subjects living in two separate regions from a steel mill

Objective Steel mills are known to be a source of ambient polycyclic aromatic hydrocarbons (PAHs), and increased cancer risk has been reported among neighborhoods previously. In this study, we tried to assess the exposure to PAHs among residents nearby to a large steel mill in Korea by measuring urinary 1-hydroxypyrene (1-OHP). Methods Two separate areas at different distances from a steel mill but on the same wind direction were chosen to evaluate the environmental exposures to polycyclic aromatic hydrocarbons. Three-hundred and fifty children living in the vicinity of steel plant (“nearby” group) and 606 children residing much farther from the factory (“remote” group) participated. Urine was collected on three consecutive days, and questionnaires about exposure to passive smoking and food consumption as well as demographics were obtained. Routine monitoring data of ambient pollutants were obtained and particulate matter less than 10 μm (PM₁₀) was analyzed with multiple regressions to assess the associations with urinary 1-OHP. Results The geometric mean concentration of urinary 1-OHP among nearby group (0.048 ± 1.878 μmol/mol creatinine, GM ± GSD) was approximately 1.3 times higher than that among remote group (0.036 ± 2.425 μmol/mol creatinine, GM ± GSD), and using multiple regression techniques, the difference was significant (P < 0.0001) after adjusting for confounding variables. When different periods before the sampling of urine were examined, PM₁₀ averages over 2 days, 3 days, and 1 week prior to urine sampling showed significant associations with urinary 1-OHP levels. Conclusion Our findings are consistent with the interpretation that residents nearby to a steel mill are exposed to PAHs through ambient exposures.