OBJECTIVETo establish the biological exposure limit values of urinary S-phenylmercapturic acid (SPMA) for assessing occupational exposure to benzene.

METHODSStudy participants were selected from 55 workers of benzene exposures below 32.5 mg/m(3). The concentration of personal exposure to benzene was measured by gas chromatography and sampled with personal sampler. The urine samples were collected at the end of work shift and individual internal exposure level was evaluated by determination of SPMA in urine by HPLC/MS method. Comparison of external and internal exposure was assessed by the relative internal exposure (RIE) index.

RESULTSThe benzene exposure level ranged from 0.71 to 32.17 mg/m(3) (geometric mean 6.98 mg/m(3), median 7.50 mg/m(3)). The urinary SPMA at the end of the work shift were significantly correlated with benzene exposure, (microg/g Cr) = -8.625 + 18.367X (mg/m(3)), r = 0.8035, (P < 0.01). According to the occupational exposure limit for benzene in China and calculation of regression equation, the expected value of urinary SPMA was 101.58 microg/g Cr. Mean level of biotransformation of per mg/m(3) benzene to urinary SPMA was 18.23 microg/g Cr and the metabolic efficiencies of benzene transformation to urinary SPMA decreased with benzene exposure increased.

CONCLUSIONBased on abroad documents and data, biological limit value for occupational exposure to benzene in China is recommended as follows: 100 microg/g Cr (47 micromol/mol Cr) for SPMA in the urine at the end of shift.

Acetylcysteine ; analogs & derivatives ; urine ; Adult ; Benzene ; adverse effects ; analysis ; Benzene Derivatives ; urine ; China ; Humans ; Middle Aged ; Occupational Exposure ; adverse effects ; analysis ; Threshold Limit Values ; Young Adult

Benzene ; adverse effects ; analysis ; chemistry ; Catalysis ; Humans ; Occupational Exposure ; Risk Assessment ; Vehicle Emissions ; analysis ; Workplace

Objective: This study was designed to conduct a retrospective and systematic occupational health risk assessment (OHRA) of enterprises that used benzene, toluene, and xylene (BTX) in Shanghai, China. Methods: All data for the study were obtained from 1,705 occupational health examination and evaluation reports from 2013 to 2017, and a semiquantitative model following Chinese OHRA guidelines (GBZ/T 298-2017) was applied for the assessment. Results: The selected enterprises using BTX were mainly involved in manufacturing of products. Using the exposure level method, health risk levels associated with exposure to BTX were classified as medium, negligible, or low. However, the risk levels associated with benzene and toluene were significantly different according to job types, with gluers and inkers exhibiting greater health risks. For the same job type, the health risk levels assessed using the comprehensive index method were higher than those using the exposure level method. Conclusion Our OHRA reveals that workers who are exposed to BTX still face excessive health risk. Additionally, the risk level varied depending on job categories and exposure to specific chemicals. Therefore, additional control measures recommended by OHRA guidelines are essential to reduce worker exposure levels.
Air Pollutants, Occupational/analysis* ; Benzene/analysis* ; China ; Humans ; Occupational Exposure/adverse effects* ; Retrospective Studies ; Risk Assessment ; Toluene/analysis* ; Xylenes/analysis*

OBJECTIVETo explore the association between polycyclic aromatic hydrocarbons (PAHs) exposure and telomere length (TL), so as to investigate the effective biomarkers to evaluate the genetic damage in peripheral blood of workers exposed to PAHs.

METHODSThe exposure group consisted of 145 coke-oven workers (including 30 top-oven workers, 76 side-oven workers and 39 bottom-oven workers), and the non-exposure control group comprised 68 medical staffs. At 6 hours after the weekend duty shift, the samples of urine and 1 ml venous blood were collected from each subject. Airborne benzene-soluble matter (BSM) and particulate-phase B(a)P in the working environment of coke-oven and controls were sampled and analyzed. The concentration of urinary 1-hydroxypyrene (1-OHPyr) was determined. A real-time PCR method was used to determine the relative telomere length (RTL) of genomic DNA in peripheral blood. The relationship between the RTL and external exposure of PAHs, the potential factors which might have influence on TL were analyzed.

RESULTSThe medians of air BSM and particulate-phase B(a)P were higher in coke-oven (BSM: 328.6 µg/m(3); B(a)P: 926.9 ng/m(3)) than those in control working environment (BSM:97.8 µg/m(3); B(a)P: 49.1 ng/m(3)). The level of 1-OHPyr among coke-oven workers was significantly higher than that of non-exposed group (12.2 µmol/mol Cr vs 0.7 µmol/mol Cr; t = 26.971, P < 0.01). RTL in coke-oven workers were significantly shorter than those of controls (1.10 ± 0.75 vs 1.43 ± 1.06; t = 2.263, P = 0.026), and after adjusting for cigarettes per day and urinary 1-OHPyr, the significant difference was still observed (F(adju) = 5.496, P(adju) = 0.020). Stratification analysis found that RTL among the male and non-drinking groups in coke-oven workers were shorter than those the same sex and alcohol using status in controls (1.08 ± 0.73 vs 1.51 ± 1.10, F = 9.212, P = 0.003; 0.96 ± 0.38 vs 1.26 ± 0.46, F = 6.484, P = 0.012). Significant correlation between RTL and age was found (r = -0.284, P = 0.019) in non-exposure group.

CONCLUSIONPAH-exposure has effect on TL of genomic DNA in peripheral blood, which is mainly observed in the male and non-drinking groups between PAH-exposed workers and controls. It indicates that TL of genomic DNA in peripheral blood might be an effective biomarker as PAH-induced genetic damage.

Adult ; Benzene ; Case-Control Studies ; Coke ; DNA Damage ; Female ; Humans ; Male ; Occupational Exposure ; adverse effects ; analysis ; Polycyclic Aromatic Hydrocarbons ; adverse effects ; analysis ; Pyrenes ; analysis ; Telomere ; drug effects ; genetics

Adult ; Air Pollutants, Occupational ; adverse effects ; Benzene ; adverse effects ; Blood Cell Count ; Commerce ; Environmental Monitoring ; Female ; Hemoglobins ; analysis ; Humans ; Male ; Middle Aged ; Occupational Exposure ; adverse effects ; Ownership

OBJECTIVETo study the relationship between low benzene exposure doses with workers' peripheral blood parameters of different similar exposure groups (SEG).

METHODSThe workers were from a shoe factory and divided into different SEG, according to the observation method and sampling method. Exposure levels, blood samples and job histories were collected. The relationship between benzene level and blood routine were analyzed using multiple regression method.

RESULTSFive SEGs were defined. No significant differences were found among different SEG in length of service, smoking, drinking, blood routine and symptoms except for ages. Significant negative correlation (r = -0.36, P < 0.05) between benzene exposure levels and white blood cell counts were found by multiple regression analysis. Similar negative correlation was also found between length of benzene exposure and red blood cell counts (r = -0.29, P < 0.05). No significantly statistical relationships were found between benzene exposure and red blood cell counts or platelet count.

CONCLUSIONSEGs method is sensitive for determining the relationship between benzene exposure levels and white blood cell counts. Further study is needed by increasing the number of workers to study the relationship between low benzene exposure and peripheral blood parameters.

Benzene ; adverse effects ; analysis ; Blood Cell Count ; Carcinogens ; adverse effects ; analysis ; China ; Dose-Response Relationship, Drug ; Environmental Monitoring ; instrumentation ; methods ; Humans ; Industry ; No-Observed-Adverse-Effect Level ; Occupational Exposure ; adverse effects ; analysis

OBJECTIVETo find out and analyze differentially expressed miRNAs in the plasma of benzene exposed workers, and explore the potential roles of plasma miRNAs in the development of hematologic toxicity induced by benzene exposure.

METHODSBy individual matching, low blood cell group, unstable blood cell group and normal group of 10 benzene exposed workers in each group were taken as subjects. Microarray was used to find out differentially expressed miRNAs among three groups. Three miRNAs validated by real-time quantitative PCR. Target genes of 9 miRNAs with the high abundance and significant difference were predicted using Target scan, Picture and miRanda softwares. David 6.7 online platform was used to perform GO term enrichment and KEGG pathway analysis of those targets.

RESULTSMicroarray screened out that 138 miRNAs were differentially expressed. Three significant classes of differentially expressed miRNAs were found with the cluster analysis. The detected expressions of miR-638, let-7f-5p and miR-223-3p by relative RT-qPCR was consistent with the microarray date. Pathway analysis showed that the most enriched pathway was focal adhesion, with 6 potential functional targets, including SOS₂, VCL, CCND2, COL4A6, IGF1 and MAPK1.

CONCLUSIONWe have identified the plasma miRNA profile in benzene exposed workers, and further analysis indicates that focal adhesion-associated miRNAs play a potential role in hematologic toxicity induced by benzene exposure.

Adult ; Benzene ; adverse effects ; Female ; Humans ; Male ; MicroRNAs ; genetics ; Middle Aged ; Occupational Exposure ; adverse effects ; Oligonucleotide Array Sequence Analysis ; Young Adult

OBJECTIVES: We evaluated the health effects of exposure to BTEX (Benzene, Toluene, Ethylbenzene, m,p-Xylene, o-Xylene) in the Taean area after the Hebei Spirit oil spill. METHODS: We used a questionnaire survey to look for health effects among 80 pregnant women 2 to 3 months following the Hebei Spirit oil spill. Their BTEX exposures were estimated using the CALPUFF method. We then used a multiple logistic regression analysis to evaluate the effects of BTEX exposure on the women's health effets. RESULTS: Pregnant women who lived near the accident site reported more symptoms of eye irritation and headache than those who lived farther from the site. There was a trend of decreasing symptoms with an increase in distance from the spill site. Pregnant women exposed to higher ambient cumulative levels of Xylene were significantly more likely to report symptoms of the skin (OR 8.01 95% CI=1.74-36.76) in the first day after the accident and significantly more likely to report abdominal pain (OR 3.86 95% CI=1.02-14.59 for Ethylbenzene, OR 6.70 95% CI=1.82-24.62 for Xylene) during the 1st through 4th days following the accident. CONCLUSIONS: This study suggests that exposure to BTEX from an oil spill is correlated with an increased risk of health effects among pregnant women. This implies the need to take proper measures, including the development of a national policy for environmental health emergencies and a plan for studying the short- and long-term chronic health effects associated with such spills.
Adult ; Benzene/*adverse effects/analysis ; Benzene Derivatives/*adverse effects/analysis ; *Disasters ; *Environmental Exposure ; Environmental Pollutants/*adverse effects/analysis ; Eye Diseases/chemically induced/epidemiology ; Female ; Health Surveys ; Humans ; *Petroleum ; Pregnancy ; Questionnaires ; Respiratory Tract Diseases/chemically induced/epidemiology ; Risk Factors ; Skin Diseases/chemically induced/epidemiology ; Time Factors ; Toluene/analysis ; *Women's Health ; Xylenes/analysis

OBJECTIVETo study the influence of occupational exposure and smoking on lung ventilation function of coke oven workers.

METHODSEnvironmental monitoring was performed on the top, side and bottom of some coke ovens. Lung ventilation function test was performed in 234 coke oven workers.

RESULTSThe 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.

CONCLUSIONThe lung ventilation function of coke oven workers has certain negative correlation with both occupational exposure and smoking.

Adult ; Air Pollutants, Occupational ; analysis ; Benzene ; analysis ; Coke ; Forced Expiratory Volume ; Humans ; Lung ; physiopathology ; Male ; Middle Aged ; Occupational Exposure ; adverse effects ; Pulmonary Ventilation ; physiology ; Smoking ; physiopathology

OBJECTIVETo study the relationship between glutathione S transferase M1(GST mu) gene deletion and leukemia in workers exposed to benzene.

METHODSA matched population-based case-control survey with multivariate Logistic regression analysis was conducted in this study.

RESULTSIn the population of 34 patients and their matched controls, the absence of the GST mu genotype conferred odds ratio of 3.6. It suggested that GST mu was an important determinant of heterogeneity in individual susceptibility to leukemia associated with exposure to benzene. The single-variance analysis indicated that these markedly significant factors were GST mu gene deletion, GST mu isoenzyme activity, duration of exposure, GST isoenzyme activity, smoking quantity and average concentration of benzene in workshop air. The multivariate analysis indicated that these markedly significant factors were GST mu gene deletion, duration of exposure to benzene and GST mu isoenzyme activity.

CONCLUSIONGST mu gene deletion may be associated with increased risk of leukemia in workers exposed to benzene and is one of genetically determined factors.

Benzene ; toxicity ; Case-Control Studies ; Gene Deletion ; Glutathione Transferase ; genetics ; Humans ; Leukemia ; enzymology ; etiology ; genetics ; Logistic Models ; Multivariate Analysis ; Occupational Exposure ; adverse effects