Occupational exposure to aromatic hydrocarbons and polycyclic aromatic hydrocarbons at a coke plant.

OBJECTIVES: The objective of this study was to assess the external exposure to aromatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) of coke-oven workers and by-product workers at a coke plant in Poland. METHODS: The content of benzene, toluene, xylene, and naphthalene in a gaseous phase and the content of dibenzo[a,h]anthracene, benz[a]anthracene, anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benz[ghi]perylene, chrysene, and indeno[1,2,3-c,d]pyrene in a particulate phase of coke plant workers were measured in the workers mentioned above. A toxic equivalency factor BaP(eq) was used to estimate human health risk associated with respiratory exposure to PAHs. RESULTS: Time-weighted values of the exposure to AHs in the coke plant were as follows: benzene (range 0.01-2.71 mg m(-3)), toluene (0.01-1.73 mg m(-3)), xylene (0.01-0.78 mg m(-3)), naphthalene (6.0-6079 µg m(-3)), and the concentrations of hydrocarbons did not exceed the exposure limits. The results for particle-bound PAHs were equal to 1.96 µg m(-3) for B(a)P, 0.73 µg m(-3) for DBA, 3.23 µg m(-3) for BaA, 4.35 µg m(-3) for BbF, 3.02 µg m(-3) for BkF, 4.54 µg m(-3) for IND, 4.32 µg m(-3) for CHR, and 0.73 µg m(-3) for Ant. The results of personal air measurements (median values of the sum of nine carcinogenic PAHs) were 2.115 µg m(-3) (coke-oven workers, n = 207), 0.326 µg m(-3) (coke by-product workers, n = 33), and 0.653 µg m(-3) (total area workers, n = 38). The benzo[a]pyrene equivalent concentrations (BaP(eq)) of 10 PAHs were 1.33, 0.183, and 0.284 µg m(-3), respectively. CONCLUSIONS: We found out that coke plant workers are simultaneously exposed to a mixture of aromatic and polycyclic hydrocarbons present in the breathing zone air. Exposure levels are significantly influenced by job categories. Coke by-product workers are significantly more exposed to benzene, toluene, and xylene and less to PAHs. Coke-oven workers are mainly exposed to PAHs. Coke-oven workplaces (top side, coke side, and push side) are characterized by higher carcinogenic risk than other coke plant workplaces.

Simultaneous determination of 2-methoxyphenol, 2-methoxy-4-methylphenol, 2,6-dimethoxyphenol and 4'-hydroxy-3'-methoxyacetophenone in urine by capillary gas chromatography.

A method for the simultaneous determination of 2-methoxyphenol, 2-methoxy-4-methylphenol, 2,6-dimethoxyphenol and 4'-hydroxy-3'-methoxyacetophenone in urine has been described. The metabolites were analyzed after enzymatic hydrolysis and extraction on octyl (C8) cartridges by using gas chromatography with flame ionization detection and a 5/95% copolymer of diphenyl-poly(dimethylsiloxane) capillary column. Methoxyphenols were well separated within 12 min. Recovery was over 90% in the range from 0.5 to 20 microg/ml; the detection limit was varying in the range of 0.05-0.11 microg/ml. The relative standard deviations and the accuracy were in the range of 3.1-15.5 and 2.4-16.0%, respectively.

Occupational exposure to aromatic hydrocarbons at a coke plant: Part I. Identification of hydrocarbons in air and their metabolites in urine by a gas chromatography-mass spectrometry method.

A method for the qualitative analysis of aromatic hydrocarbons in air and their various urinary metabolites is presented. The air was sampled in charcoal tubes and extracted with carbon disulfide. The hydrocarbons were identified as being aliphatic hydrocarbons (C(9)-C(19)), aromatic hydrocarbons and heterocyclic compounds. The urinary metabolites after enzymatic hydrolysis were analyzed by solid-phase extraction with a styrene-divinylbenzene resin, silylation with N,O-bis(trimethylsilyl)acetamide and GC/MS for separation and detection. Satisfactory separation of all compounds investigated was achieved without interference due to matrix peaks. The following compounds were identified in the urine of workers: dimethylphenol isomers, 4-ethyl-1,3-benzenediol, 2-ethoxybenzoic acid and methoxyphenols. Trimethylsilyl derivatives of aromatic hydroxyacids and hydroxymethoxyacids were found in the urine of occupationally exposed workers by means of a silylation procedure.

occupational exposure to aromatic hydrocarbons at a coke plant: Part II. Exposure assessment of volatile organic compounds.

The objective of the study is to assess the external and internal exposures to aromatic hydrocarbons in the tar and oil naphthalene distillation processes at a coke plant. 69 workers engaged as operators in tar and oil naphthalene distillation processes and 25 non-exposed subjects were examined. Personal analyses of the benzene, toluene, xylene isomers, ethylbenzene, naphthalene, indan, indene and acenaphthene in the breathing zone air allowed us to determine the time weighted average exposure levels to the aromatic hydrocarbons listed above. The internal exposure was investigated by measurement of the urinary excretion of naphthols, 2-methylphenol and dimethylphenol isomers by means of gas chromatography with a flame ionization detection (GC/FID). Urine metabolites were extracted after enzymatic hydrolysis by solid-phase extraction with styrene-divinylbenzene resin. The time-weighted average concentrations of the hydrocarbons detected in the breathing zone air shows that the exposure levels of the workers are relatively low in comparison to the exposure limits. Statistically significant differences between average concentrations of aromatic hydrocarbons (benzene, toluene, xylene isomers) determined at the workplaces in the tar distillation department have been found. Concentrations of the naphthalene and acenaphthene detected in workers from the oil distillation department are higher that those from the tar distillation department. Concentrations of naphthols, 2-methoxyphenol and dimethylphenol isomers in the urine of occupationally exposed workers were significantly higher than those of non-exposed subjects. Concentrations of the 2-methoxyphenol and dimethylphenol isomers in urine were significantly higher for the tar distillation workers, whereas concentrations of naphthols were higher for the oil naphthalene distillation workers. Operators at the tar and naphthalene oil distillation processes are simultaneously exposed to a mixture of different hydrocarbons, mainly benzene and naphthalene homologues.

Occupational exposure to phenolic compounds at coke plants--urinary excretion of methoxyphenols as an indicator of exposure to methoxyphenols.

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/m(3), 15.4 ng/m(3) and 92.5 ng/m(3) 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.