Coke Oven Workers Research Articles

Associations Between Exposure to Polycyclic Aromatic Hydrocarbons and Temporal Change of Urinary 1-Hydroxypyrene Levels in Taiwanese Coke-Oven Workers

Our aim is to analyze the association between polycyclic aromatic hydrocarbon (PAH) exposure and the temporal change of urinary 1-hydroxypyrene (1-OHP). Two personal air samples, eight spot urine samples, and questionnaires were used to collect PAH exposure, urinary 1-OHP, demographic data, and environmental pollutants. Topside-oven workers had significantly higher levels of PAH exposure and 1-OHP than side-oven workers. Urinary 1-OHP was a biomarker for PAH exposure. In topside-oven workers, the trend of 1-OHP increased sharply and reached the top in the sixth day after work and declined dramatically on days off. In side-oven workers, such a trend was not found, and those who smoked showed a slight increase in urinary 1-OHP levels on days off. We suggest that the pattern of temporal change of urinary 1-OHP levels is different between topside-oven and side-oven workers.

Risk factors of fatty liver disease among coke oven workers

目的 研究焦化作业工人脂肪肝的主要危险因素,为探讨焦炉逸散物(COE)的肝损伤作用提供依据.方法 选择武钢焦化厂炼焦和化产作业工龄1年以上的男性工人1 114人为暴露组;选择不接触焦炉逸散物的武钢能源总厂供水、供电作业工龄1年以上的男性工人736人为对照组.采用两因素和多因素非条件Logistic回归分析危险因素与脂肪肝之间的关系.结果 暴露组脂肪肝检出率(20.0%)高于对照组(16.2%),差异有统计学意义(P＜0.05).从两因素Logistic分析结果可以看出,在分别平衡了其他因素的影响之后,脂肪肝与焦化作业有关;平衡了焦化作业影响之后,脂肪肝与年龄、工龄、肥胖、高血压、高血脂、高血糖、丙氨酸转移酶(ALT)异常等因素密切相关,与吸烟、饮酒、HBsAg关系不明显.从多因素Logistic分析结果可以看出,焦炉作业(x3)、炉辅作业(x4)和化产作业(x5)均入选成为脂肪肝的危险因素,而且OR3(1.928)＞OR4(1.837)＞ OR5(1.721),与作业环境有害物质浓度较为吻合.脂肪肝与肥胖(x6、x7)、高血压(x10)、高血脂(x11)、高血糖(x12)和ALT异常(x13)密切相关,其中肥胖(x6、x7)影响最大,并且OR值随体重指数(BMI)升高而增大.结论 焦化作业工人脂肪肝与其职业暴露密切相关,代谢综合征(MS)对焦化作业工人脂肪肝的发生具有重要作用,COE有可能造成肝损伤而导致脂肪肝,应引起高度重视。

Biological Monitoring of Environmental Exposure to Polycyclic Aromatic Hydrocarbons: 1-Hydroxypyrene in Urine of Turkish Coke Oven Workers

Biological Monitoring of Environmental Exposure to Polycyclic Aromatic Hydrocarbons: 1-Hydroxypyrene in Urine of Turkish Coke Oven Workers

P1105 コークス炉作業者の多環芳香族炭化水素類の曝露濃度と尿中代謝産物の関係(一般演題:ポスター,地方の時代の産業保健,第79回日本産業衛生学会)

P1105 コークス炉作業者の多環芳香族炭化水素類の曝露濃度と尿中代謝産物の関係(一般演題:ポスター,地方の時代の産業保健,第79回日本産業衛生学会)

Sensitive biomarker of polycyclic aromatic hydrocarbons (PAHs): urinary 1-hydroxyprene glucuronide in relation to smoking and low ambient levels of exposure

The study was conducted in a Chinese population with occupational or environmental exposures to polycyclic aromatic hydrocarbons (PAHs). A total of 106 subjects were recruited from coke-oven workers (workers), residents in a metropolitan area (residents) and suburban gardeners (gardeners). All subjects were monitored twice for their personal exposures to PAHs. The biological samples were collected for measurements of 1-hydroxypyrene (1-OHP) and cotinine in urine. The geometric means of personal exposure levels of pyrene, benz(a)anthracene (BaA) and benzo(a)pyrene (BaP) in workers were 1.470, 0.978 and 0.805 µg m−3, respectively. The corresponding levels in residents were 0.050, 0.034 and 0.025 µg m−3; and those in gardeners were 0.011, 0.020 and 0.008 µg m−3, respectively. The conjugate of 1-OHP with glucuronide (1-OHP-G) is the predominant form of pyrene metabolite in urine and it showed strong associations with exposures not only to pyrene, but also to BaA, BaP and total PAHs. Most importantly, a significant difference in 1-OHP-G was even detected between the subgroups with exposures to BaP at < 0.010 and > 0.010 but < 0.020 µg m−3, suggesting that 1-OHP-G is a good marker that can be used for the risk assessment of BaP exposure at levels currently encountered in ambient air. Furthermore, multiple regression analyses of 1-OHP-G on PAHs exposure indicated that cigarette smoke was a major confounding factor and should be considered and adjusted for while using 1-OHP to estimate PAHs exposure.

Elevated levels of urinary 8-hydroxy-2 -deoxyguanosine, lymphocytic micronuclei, and serum glutathione S-transferase in workers exposed to coke oven emissions.

To investigate associations among occupational exposure to coke oven emissions (COEs), oxidative stress, cytogenotoxic effects, change in the metabolizing enzyme glutathione S-transferase (GST), and internal levels of polycyclic aromatic hydrocarbons (PAHs) in coke oven workers, we recruited 47 male coke oven workers and 31 male control subjects from a coke oven plant in northern China. We measured the levels of 1-hydroxypyrene (1-OHP) and 8-hydroxy-2′-deoxyguanosine (8-OHdG) in urine, micronucleated binucleated cells (BNMNs) in peripheral blood lymphocyte, and GST in serum. Our results showed that the group exposed to COEs had significantly increased levels of 1-OHP [median 5.7; interquartile range (IQR), 1.4–12.0 μmol/mol creatinine] compared with the control group (3; 0.5–6.4 μmol/mol creatinine). In addition, the median levels (IQR) of 8-OHdG, BNMNs, and GST were markedly increased in the exposed [1.9 (1.4–15.4) μmol/mol creatinine; 6 (2–8) per thousand; 22.1 (14.9–31.2) U/L, respectively] compared with controls [1.3 (1.0–4.0) μmol/mol creatinine, 2 (0–4) per thousand; and 13.1 (9.5–16.7) U/L, respectively]. These results appeared to be modified by smoking. However, multivariate logistic regression analysis revealed that exposure to COEs had the highest odds ratio among variables analyzed and that smoking was not a significant confounder of the levels of studied biomarkers. Overall, the present findings suggest that COE exposure led to increased internal PAH burden, genetic damage, oxidative stress, and GST activity. The consequences of the changes in these biomarkers, such as risk of cancer, warrant further investigations.

Sperm DNA damage correlates with polycyclic aromatic hydrocarbons biomarker in coke-oven workers

The aim was to determine whether occupational exposure to polycyclic aromatic hydrocarbons (PAHs) in men has adverse effect on semen quality. Forty-eight coke-oven workers, including 16 topside-oven (TO) workers and 32 sideoven (SO) workers, were studied. Ambient PAHs exposure, urinary 1-hydroxypyrene (1-OHP) levels, and parameters of semen quality were determined. TO workers had significantly higher ambient PAHs exposure (3,436.1+/-3,411.0 vs. 1,123.1+/-1,829.3 ng/m3, P < 0.01), urinary 1-OHP levels (207.8+/-176.4 vs. 54.0+/-44.8 microg/g, P < 0.001), frequency of oligospermia (18.8 vs. 0%, P < 0.05), and morphological abnormality in sperm (32.3 vs. 14.6%, P < 0.01) than SO workers. Among cigarette smokers, TO workers had significantly higher rates of DNA denaturation in spermatozoa (alphaT) and percentage of sperm with increased DNA denaturation (COMP alphaT) levels than SO workers (246.2+/-49.5 vs. 198.1+/-30.3 for alphaT; 34.8+/-14.4 vs. 19.3+/-13.9% for COMP alphaT, P < 0.05). There was a positive correlation between urinary 1-OHP and alphaT, COMP alphaT, and abnormal sperm morphology and a tenfold increase in urinary 1-OHP associated with a 2.35-fold increase in alphaT, as well as a 1.07-fold increase in percentage of sperm with abnormal morphology. A potential risk of sperm dysfunction should be considered for workers occupationally exposed to high levels of PAHs. Cigarette smoking may aggravate this risk. Urinary 1-OHP can be used as a biomarker predicting sperm dysfunction.

Analysis of serum glutathione S-transferase and urinary 8-hydroxy-2-deoxyguanosine in coke oven workers

To investigate the application of serum glutathione S-transferase (GST) and urinary 8-hydroxy-2-deoxyguanosine (8-OHdG) as the monitoring biomarkers for coke oven workers exposed to polycyclic aromatic hydrocarbons (PAHs). 47 male coke oven workers and 31 male control workers were investigated. Urinary 8-OHdG and serum GST were analyzed using high performance liquid chromatography (HPLC) with electrochemical detection and test kit. Urinary 1-hydroxypyrene (1-OHP) as internal exposure of PAHs was also determined simultaneously by alkaline hydrolysis and HPLC. The values of urinary 1-OHP, serum GST and urinary 8-OHdG were reported as median with interquartile range (P(25)-P(75)). Urinary 1-OHP [5.7 (1.4-12.0) micromol/mol Cr], serum GST [22.1 (14.9-31.2) U/ml], and urinary 8-OHdG [1.9 (1.4-15.4) micromol/mol Cr] in coke oven workers were significantly higher than in control workers [3.0 (0.5-6.4) micromol/mol Cr (P < 0.05), 13.1 (9.5-16.7) U/ml (P < 0.01), and 1.3 (1.0-4.0) micromol/mol Cr (P < 0.05) respectively]. Categorizing by smoking status, significant differences in urinary 1-OHP and serum GST were found only in smokers among coke oven workers compared to control workers (P < 0.01), and 8-OHdG levels only in non-smokers (P < 0.01). Additionally, there was significant correlation between urinary 1-OHP and serum GST activity (r(s) = 0.31, P < 0.01, n = 78). The multiple logistic regression analysis showed that coke oven workers were at the higher risk of having GST activities above 16.7 U/ml (OR = 13.2) and 8-OHdG levels above 1.8 micromol/mol creatinine (OR = 4.4). High body mass index was an independent factor to affect urinary 8-OHdG levels. The elevated serum GST activities and increased oxidative DNA damage were found in the coke oven workers. Occupational exposure and smoking interact on each other. Serum GST may be used as a biomarker for assessing the exposure of PAHs. Assay of urinary 8-OHdG may be useful for evaluating the risk of lung cancer in coke oven workers.

Association of XRCC1 polymorphisms and chromosomal damage levels in coke-oven workers

To investigate the association of XRCC1 polymorphisms and chromosomal damage levels in peripheral blood lymphocyte in coke-oven workers. The study included 141 coke-oven workers who exposed to a high level of polycyclic aromahaplotpetic hydrocarbon and 66 non-exposed controls. Urinary 1-hydroxypyrene and chromosome damage in peripheral lymphocyte were measured. Four -tagging single nucleotide polymorphisms in XRCC1 gene, including C26304T, G27466A, G28152A and G36189A, were detected and the XRCC1 haplotypes were estimated by using an extension of Clark algorithm. The associations between haplotype pairs and micronuclei data were assessed by analysis of covariance in the exposed and non-exposed groups. The geometric means of urinary 1-hydroxypyrene levels in coke-oven workers and the controls were 12.0 and 0.7 micromol/mol Cr respectively (P < 0.01). The cytokinesis-block micronucleus cytokinesis-block micronucleus frequencies (number of micronucleus per 1 000 binucleated lymphocytes) was significantly higher in coke-oven workers (0.95 +/- 0.66)% than in the controls (0.40 +/- 0.36)%, P < 0.01. The haplotype CGGG was associated with the decreased frequencies of total micronucleus, and the haplotypes TGGG (P = 0.01) and CGAG (P < 0.05) were associated with the increased frequencies of total micronucleus in the multivariate analysis with adjustment for covariates among coke-oven workers. The genetic polymorphisms of XRCC1 gene could influence the chromosome damage levels in coke-oven workers.

The Association of XRCC1 Haplotypes and Chromosomal Damage Levels in Peripheral Blood Lymphocyte among Coke-Oven Workers

Theoretically, a haplotype has a higher level of heterozygosity than individual single nucleotide polymorphism (SNP) and the association study based on the haplotype may have an increased power for detecting disease associations compared with SNP-based analysis. In this study, we investigated the effects of four haplotype-tagging SNPs (htSNP) and the inferred haplotype pairs of the X-ray cross-complementing group 1 (XRCC1) gene on chromosome damage detected by the cytokinesis-block micronucleus assay. The study included 141 coke-oven workers with exposure to a high level of polycyclic aromatic hydrocarbons and 66 nonexposed controls. The frequencies of total MN and MNed cells were borderline associated with the Arg(194)Trp polymorphism (P = 0.053 and P = 0.050, respectively) but not associated with the Arg(280)His, Arg(399)Gln and Gln(632)Gln polymorphisms among coke-oven workers. Five haplotypes, including CGGG, TGGG, CAGG, CGAG, and CGGA, were inferred based on the four htSNPs of XRCC1 gene. The haplotype CGGG was associated with the decreased frequencies of total MN and MNed cells, and the haplotypes TGGG and CGAG were associated with the increased frequencies of total MN and MNed cells with adjustment for covariates among coke-oven workers. This study showed that the haplotypes derived from htSNPs in the XRCC1 gene were more likely than single SNPs to correlate with the polycyclic aromatic hydrocarbon-induced chromosome damage among coke-oven workers.

Association of metabolic and DNA repair enzyme gene polymorphisms and DNA damage in coke-oven workers

To investigate the association of polymorphisms of metabolic and DNA repair enzyme genes and DNA damage in peripheral blood lymphocytes in coke-oven workers. One hundred and forty-four coke-oven workers and 50 controls were recruited in this study. Urinary 1-hydroxypyrene (1-OHP) levels were measured as the internal dose of polycyclic aromatic hydrocarbons exposure. DNA damage was detected by alkaline comet assay, and the value of 1.74 was used as the cut-off value to determine whether the individual's DNA damage was positive. The genotypes of CYP1A1, CYP2E1, GSTP1, NQO1, mEH and XRCC1 were determined by PCR-based methods. With adjustment for urinary 1-OHP, age, sex, multiple analysis of covariance was used to study the association between genotypes and the ln-transformed olive TM and multiple logistic regression was used to calculate the adjusted OR and the 95% CI for the risk of DNA damage. In 144 coke-oven workers, with adjustment for urinary 1-OHP, coking history and sex, the olive TM was significantly higher with XRCC1 280His allele than those with Arg allele (5.6 vs. 2.8, P < 0.01). The subjects with XRCC1 280His allele also have significantly higher risk for DNA damage than subjects with Arg allele (adjusted OR = 2.66, 95% CI = 1.00-7.14, P = 0.05) and the subjects with GSTP1 104Val allele have higher risk for DNA damage than subjects with Ile allele (adjusted OR = 1.90, 95% CI = 0.94-3.85, P = 0.07). XRCC1 and GSTP1 polymorphisms might influence the susceptibility of DNA damage in occupational PAH-exposed coke-oven workers.

The influence of occupational exposure and smoking on lung ventilation of coke oven workers

To study the influence of occupational exposure and smoking on lung ventilation function of coke oven workers. Environmental monitoring was performed on the top, side and bottom of some coke ovens. Lung ventilation function test was performed in 234 coke oven workers. The poison concentration in environment had such tendency as it was the highest on the top, then the side, and the lowest at the bottom. The standardized forced expiratory volume in the 1st second (FEV(1), 90.8% +/- 8.6%) and forced expiratory rate (FEV(1)%, 95.4% +/- 12.4%) of those coke oven workers who smoked were significantly lower than those non-smoking workers (100.9% +/- 14.3%, 108.9% +/- 17.6%); among those smoking workers, the partial correlation coefficients between forced vital capacity (FVC) and benzene soluble, benzopyrene, and smoking index were -0.249, -0.187 and -0.368 respectively; and the coefficients between FEV(1) and the three aspects were -0.255, -0.191 and -0.388; and the coefficients between FEV(1)% and them were -0.131, -0.107 and -0.065. Among those non-smoking workers, the coefficients between benzene solubles and FVC, FEV(1) and FEV(1)% were -0.154, -0.052 and -0.176, and between benzopyrene and them were -0.121, -0.037 and -0.159. The lung ventilation function of coke oven workers has certain negative correlation with both occupational exposure and smoking.

DNA adduct formation of benzo[ a]pyrene in white blood cells of workers exposed to polycyclic aromatic hydrocarbons

The major DNA adducts of anti-benzo[ a]pyrene diolepoxide (BPDE) were determined by high performance liquid chromatography with fluorescence detection (HPLC-FLD) in white blood cells (WBC) of workers exposed to benzo[ a]pyrene (B[ a]P). In addition, ambient concentrations of B[ a]P at the workplace were determined by personal air sampling. Workers in a refractory setting were examined before ( n = 26 ) and 3 months after ( n = 33 ) changing the production material (binding pitch). Furthermore, 9 coke oven workers were examined. The change in the production process in the refractory setting led to a decrease in the median of ambient B[ a]P concentrations (0.14 to <0.07 μg/m 3). The median of BPDE-DNA adduct levels in WBC also decreased from 0.9 adducts/10 8 nucleotides before changing the production material to <0.5 adducts/10 8 nucleotides 3 months afterwards. The B[ a]P concentrations at the workplace for the coke oven workers were found to be significantly higher than in the refractory setting. However, BPDE-DNA adduct concentrations in coke oven workers and refractory setting workers showed no significant difference, which was probably due to the low number of studied subjects in the coke-oven setting. No significant differences could be observed for BPDE-DNA adduct levels between current smokers ( n = 21 ) and non-smokers ( n = 14 ; p = 0.93 ) from both plants. In addition, no correlation between B[ a]P concentrations in the air and DNA adduct levels in refractory workers and in coke oven workers could be found ( r = - 0.03 , p = 0.87 ). Because of the missing correlation between personal air sampling and BPDE-DNA adduct levels in WBC, the results may indicate that their formation is either influenced by other routes of exposure to B[ a]P (e.g., skin absorption, dietary habits) or interindividual differences in their formation and repair.

Analysis of N7‐(benzo[a]pyrene‐6‐yl)guanine in urine using two‐step solid‐phase extraction and isotope dilution with liquid chromatography/tandem mass spectrometry

Analysis of urinary N7-(benzo[a]pyren-6-yl)guanine (BP-6-N7Gua), a DNA adduct induced by benzo[a]pyrene, may serve as a risk-associated biomarker for exposure to polyaromatic hydrocarbons (PAHs). In this study a highly sensitive and specific analytical method, incorporating on-line sample preparation coupled with isotope-dilution liquid chromatography and tandem mass spectrometry (LC/MS/MS), was developed to quantitate this adduct in human urine. In order to achieve accurate quantitation, 15N5-labeled BP-6-N7Gua was synthesized to serve as the internal standard, and a two-step solid-phase extraction (SPE) procedure using C8 and SCX cartridges was used for sample cleanup. BP-6-7-N7Gua was analyzed using positive ion LC/MS/MS operated in multiple reaction monitoring (MRM) mode. The [M+H]+ ions at m/z 402 and 407 and the common fragment ion of [M+H]+ at m/z 252 were monitored for quantification. The recovery of this analyte after two-step SPE was 90%, and the limit of detection was 2.5 fmol/mL in 10 mL of urine. This highly specific and sensitive method for BP-6-N7Gua in urine may be applied to assess exposure to PAHs in coke-oven workers for future molecular epidemiology studies on health effects of PAHs.

Relationship between heterozygosity and quantitative traits:intralocus interactions and multiple-locus averaging

Genomic dosage (copy number) of active ribosomal genes was evaluated using visual semi-quantitative method determining the sizes of Ag-NORs in acrocentric chromosomes after selective silver nitrate staining. A relationship between the length of service and the active ribosomal gene copy number was established: the highest numbers of active rRNA genes were observed in coke-oven workers with a length of service exceeding 20 years. An inverse relationship between the individual doses of active ribosomal genes and toxicogenetic susceptibility of the workers to the occupational factors was also revealed.

Argyrophil nucleolar organizer regions as biomarker of effect for polycyclic aromatic hydrocarbon exposure

To study whether the argyrophil nucleolar organizer regions (AgNOR) in T lymphocytes of peripheral blood in coke-oven workers can be used as a biomarker of effect for polycyclic aromatic hydrocarbon (PAH) exposure. Fifty-two male coke-oven workers were divided into three groups according to exposure levels of coke oven emissions: high-exposure, middle-exposure and low-exposure workers. Additionally 10 men without occupational PAH exposure were chosen as control group. Peripheral blood T lymphocytes were cultured, spread on slides and stained with silver nitrate. The ratio of AgNOR area vs. nuclear area (I/S) in T lymphocytes was analyzed. Urinary 1-hydroxypyrene (1-OHP) was measured as the internal dose of PAH exposure. Mean urinary 1-OHP level in high-exposure group (16.56 +/- 2.77 micromol/mol Cr) was significantly higher than those in low-exposure group (3.30 +/- 2.77 micromol/mol Cr, P < 0.001) and control group (3.04 +/- 1.58 micromol/mol Cr, P < 0.01). The mean I/S of AgNOR in T lymphocytes in high-exposure group (0.056 +/- 0.010) was significantly lower than those in middle-exposure group (0.065 +/- 0.013, P < 0.05), low-exposure group (0.067 +/- 0.008, P < 0.01) and control group (0.076 +/- 0.007, P < 0.001). It was also found that I/S of AgNOR were significantly decreased in middle-exposure group and low-exposure group in comparison with control group (P < 0.01, P < 0.05). The occupational exposure to PAH resulted in increase of 1-OHP in urine and decrease of AgNOR in T lymphocytes. PAH exposure might lead to damage T lymphocytes function and AgNOR may be considered as a biomarker of effect for PAH exposure.

Genomic dosages of active rRNA genes in coke-oven workers

Genomic dosages of active rRNA genes in coke-oven workers

Preliminary study on naphthalene-metabolites-albumin adduct as an exposure biomarker for coke oven workers

To study albumin adduct with naphthalene metabolites, namely 1,2-naphthoquinone (1,2-NPQ) and 1,4-naphthoquinone (1,4-NPQ), as a potential biomarker for intermediate/long-term exposure to polycyclic aromatic hydrocarbons (PAH) in coke oven workers. Twenty-eight coke oven workers and 22 control workers were recruited from a cokery. Spot urine and venous blood samples were collected from the workers after four continuously working days and personal information was obtained by questionnaire. Plasma albumin adduct was detected with gas chromatography-mass spectrometry. Albumin adduct with 1,2- & 1,4-NPQ (1,2-NPQ and 1,4-NPQ), respectively, were detected in all coke oven workers and controls. Median plasma level of 1,2-NPQ-Alb in coke oven workers was significantly higher than that in controls (76.6 pmol/g vs. 44.9 pmol/g, P < 0.01). However, there was no significant difference in plasma median level of 1,4-NPQ-Alb between the two groups (48.6 pmol/g vs. 44.2 pmol/g, P > 0.05). Plasma level of 1,2-NPQ-Alb was significantly higher than that of 1,4-NPQ-Alb in coke oven workers. Urine levels of naphthalene, 1-naphthol, 2-naphthol and 1-pyrenol in coke oven workers correlated significantly with their plasma level of 1,2-NPQ-Alb (Pearson coefficient of correlation greater than 0.371, P < 0.01), but did not do significantly with 1,4-NPQ-Alb. Plasma level of 1,2-NPQ-Alb could effectively reflect their magnitude of personal internal dose of exposure to air PAH, so it could be used as a potential biomarker to evaluate their intermediate/long-term exposure to PAH in coke oven workers.

Effects of Genetic Polymorphisms of Metabolic Enzymes on Cytokinesis-Block Micronucleus in Peripheral Blood Lymphocyte among Coke-Oven Workers

Abstract Exploring the associations between genetic polymorphisms of metabolic enzymes and susceptibility to polycyclic aromatic hydrocarbon (PAH)–induced chromosomal damage is of great significance for understanding PAH carcinogenesis. Cytochrome P450, glutathione S-transferase, microsomal epoxide hydrolase, NAD(P)H:quinone oxidoreductase, and N-acetyltransferase are PAH-metabolizing enzymes. In this study, we genotyped for the polymorphisms of these genes and assessed their effects on cytokinesis-block micronucleus (CBMN) frequencies in peripheral blood lymphocytes among 141 coke-oven workers and 66 non–coke-oven worker controls. The geometric means of urinary 1-hydroxypyrene levels in coke-oven workers and the controls were 12.0 and 0.7 μmol/mol creatinine, respectively (P &amp;lt; 0.01). The CBMN frequency (number of micronuclei per 1,000 binucleated lymphocytes) was significantly higher in coke-oven workers (9.5 ± 6.6‰) than in the controls (4.0 ± 3.6‰; P &amp;lt; 0.01). Among the coke-oven workers, age was positively associated with CBMN frequency; the mEH His113 variant genotype exhibited significantly lower CBMN frequency (8.5 ± 6.5‰) than did the Tyr113/Tyr113 genotype (11.3 ± 6.4‰; P &amp;lt; 0.01); the low mEH activity phenotype exhibited a lower CBMN frequency (8.6 ± 6.8‰) than did the high mEH activity phenotype (13.2 ± 6.7‰; P = 0.01); the GSTP1 Val105/Val105 genotype exhibited a higher CBMN frequency (15.0 ± 5.8‰) than did the GSTP1 Ile105/Ile105 or Ile105/Val105 genotypes (9.3 ± 6.5‰; P &amp;lt; 0.01); the joint effect of high mEH activity phenotype and GSTM1 null genotype on CBMN frequencies was also found. Gene-environment interactions between occupational PAH exposure and polymorphisms of mEH and/or GSTM1 were also evident. These results indicate that the mEH, GSTP1, and GSTM1 polymorphisms may play a role in sensitivity or genetic susceptibility to the genotoxic effects of PAH exposure in the coke-oven workers.

Occupational exposure profiles of polycyclic aromatic hydrocarbons in coke oven workers

To study the characteristics of occupational exposure of polycyclic aromatic hydrocarbons (PAHs) in coke oven workers. Samples were collected individually and PAHs concentration in the ambient air were assayed by high performance liquid chromatography (HPLC) and toxic equivalency factors (TEFs) were introduced to assess the carcinogenic potency. The levels of PAHs occupational exposure in oven workers at topside was higher than at side oven and bottom oven (P < 0.05). Non-carcinogenic PAHs were more than 70% of total PAHs and benzo[a]pyrene accounted for 65.5% approximately 72.4% of total benzo[a]pyrene equivalents. Total occupational exposure level of PAHs in coke oven workers was positively related to the content of benzo[a]pyrene and pyrene, respectively (r(2) = 0.84, r(2) = 0.94, P < 0.05). Coke oven workers were exposed to a high level of PAHs which possessed some extent of carcinogenic potency, and benzo[a]pyrene is the chief carcinogenic substance.