Abstract
Objectives: This study describes the exposure of coke plant workers to methoxyphenols. The relationship between exposure to methoxyphenols and urinary excretion of metabolites was examined. Methods: We determined concentrations of 2-methoxyphenol, 2-methoxy-4-methylphenol and 1-(4-hydroxy-3-methoxyphenyl)ethanone in the breathing-zone air and in the urine of workers, collected after the workshift. Urine metabolites were extracted after enzymatic hydrolysis by solid-phase extraction. Concentrations of methoxyphenols in air and urine were determined by gas chromatography with flame-ionization. Results: The time-weighted average concentrations (median) of methoxyphenols in the breathing zone air were as follows: 9.9 ng/m3, 15.4 ng/m3 and 92.5 ng/m3 for 2-methoxyphenol, 2-methoxy-4-methylphenol and 1-(4-hydroxy-3-methoxyphenyl)ethanone, respectively. The median values of urinary concentrations were as follows: 582.5, 190.1, 235.0 and 21.8 μmol/mol creatinine for 2-methoxyphenol, 2-methoxy-4 methylphenol, 1-(4-hydroxy-3-methoxyphenyl)ethanone and 2,6-dimethoxyphenol, respectively. A statistically significant correlation between the exposure level and the urinary level was found for 2-methoxyphenol (r=0.573, p<0.01). Conclusion: We found that the presence of 2-methoxyphenol in urine can be used as a biomarker for 2-methoxyphenol exposure. The analysis performed at the coke plant showed that the workers were exposed to relatively low concentrations of methoxyphenols.
