OBJECTIVES: The level of benzene exposure in the petrochemical industry during regular operation has been well established, but not in turnaround (TA), where high exposure may occur. In this study, the characteristics of occupational exposure to benzene during TA in the petrochemical companies were investigated in order to determine the best management strategies and improve the working environment. This was accomplished by evaluating the exposure level for the workers working in environments where benzene was being produced or used as an ingredient during the unit process. METHODS: From 2003 to 2008, a total of 705 workers in three petrochemical companies in Korea were studied. Long- and short-term (< 1 hr) samples were taken during TAs. TA was classified into three stages: shut-down, maintenance and start-up. All works were classified into 12 occupation categories. RESULTS: The long-term geometric mean (GM) benzene exposure level was 0.025 (5.82) ppm (0.005-42.120 ppm) and the short-term exposure concentration during TA was 0.020 (17.42) ppm (0.005-61.855 ppm). The proportions of TA samples exceeding the time-weighted average, occupational exposure level (TWA-OEL in Korea, 1 ppm) and the short-term exposure limit (STEL-OEL, 5 ppm) were 4.1% (20 samples of 488) and 6.0% (13 samples of 217), respectively. The results for the benzene exposure levels and the rates of exceeding the OEL were both statistically significant (p < 0.05). Among the 12 job categories of petrochemical workers, mechanical engineers, plumbers, welders, fieldman and scaffolding workers exhibited long-term samples that exceeded the OEL of benzene, and the rate of exceeding the OEL was statistically significant for the first two occupations (p < 0.05). CONCLUSION: These findings suggest that the periodic work environment must be assessed during non-routine works such as TA.
Benzene ; Korea ; Occupational Exposure ; Occupations ; Threshold Limit Values

OBJECTIVES: The level of benzene exposure in the petrochemical industry during regular operation has been well established, but not in turnaround (TA), where high exposure may occur. In this study, the characteristics of occupational exposure to benzene during TA in the petrochemical companies were investigated in order to determine the best management strategies and improve the working environment. This was accomplished by evaluating the exposure level for the workers working in environments where benzene was being produced or used as an ingredient during the unit process. METHODS: From 2003 to 2008, a total of 705 workers in three petrochemical companies in Korea were studied. Long- and short-term (< 1 hr) samples were taken during TAs. TA was classified into three stages: shut-down, maintenance and start-up. All works were classified into 12 occupation categories. RESULTS: The long-term geometric mean (GM) benzene exposure level was 0.025 (5.82) ppm (0.005-42.120 ppm) and the short-term exposure concentration during TA was 0.020 (17.42) ppm (0.005-61.855 ppm). The proportions of TA samples exceeding the time-weighted average, occupational exposure level (TWA-OEL in Korea, 1 ppm) and the short-term exposure limit (STEL-OEL, 5 ppm) were 4.1% (20 samples of 488) and 6.0% (13 samples of 217), respectively. The results for the benzene exposure levels and the rates of exceeding the OEL were both statistically significant (p < 0.05). Among the 12 job categories of petrochemical workers, mechanical engineers, plumbers, welders, fieldman and scaffolding workers exhibited long-term samples that exceeded the OEL of benzene, and the rate of exceeding the OEL was statistically significant for the first two occupations (p < 0.05). CONCLUSION: These findings suggest that the periodic work environment must be assessed during non-routine works such as TA.
Benzene ; Korea ; Occupational Exposure ; Occupations ; Threshold Limit Values

Benzene is classified as Group 1 carcinogen by IARC. It has been found that benzene induces hematotoxicity even in low dose exposure. The identification of key events during benzene induced hematotoxicty leads to adjustment of occupational exposure limits of benzene. In this review, we focus on the exposure, metabolism, target organs, key epigenetic changes, toxicty effects and end points of low-dose chronic benzene exposure induced hematotoxicity and finally discuss the perspectives on the future study of this area.
Benzene ; toxicity ; Carcinogens ; toxicity ; Epigenesis, Genetic ; Humans ; Occupational Exposure

OBJECTIVETo analyze related factors which affect GPA mutation frequency of workers exposed to benzene, with the Glycophorin A (GPA) mutation assay and explore the possibility of GPA mutation frequency as an index of predicting the risk of benzene poisoning.

METHODSThe erythrocytes were bound with fluorescent-labeled monoclonal antibody after isolated and fixed from the peripheral blood, and then the GPA mutation assay was performed using the flow cytometry (FCM). The related factors of GPA mutation frequency were analyzed by statistical methods.

RESULTSThe GPA mutation frequency of chronic benzene poisonings was significantly higher than that of their controls (P < 0.05). Significant direct correlation was found between age, length of service, accumulative exposure score and the GPA mutation frequency of workers exposed to benzene (P < 0.01). However, there was significantly inverse correlation between the 3AB index and the GPA mutation frequency (GPAN0: r(s) = -0.589, P < 0.01, GPANN: r(s) = -0.615, P < 0.01). In the multiple factor regression analysis on GPA mutation frequency, benzene exposure and individual susceptibility both entered model of multiple factors analysis, the coefficient of determination of benzene-exposed workers was 0.819.

CONCLUSIONExposure to benzene and individual susceptibility are the most important factors that affect GPA mutation frequency. GPA mutation frequency increases with the benzene exposure and individual susceptibility.

Benzene ; poisoning ; Glycophorin ; genetics ; Humans ; Mutation ; Mutation Rate ; Occupational Exposure

Benzene ; poisoning ; Hazardous Substances ; Humans ; Occupational Exposure ; prevention & control

Background: Benzene is primarily routed by inhalation which highly sensitive to blood parameters as bone marrow is their target organ. The ability of benzene even in low exposure levels may induce human bone marrow suppression resulting in blood diseases such as leukopenia, anemia, thrombocytopenia, aplastic anemia, and pancytopenia. In the occupational setting, the most common benzene-exposed workers are from the petrochemical industries and petrol distribution such as gasoline pumps. Benzene also generated primarily by mobile exhaust and some from various of anthropogenic sources at environmental atmosphere and occupationally exposed in the policemen traffic, taxi and bus drivers, and street vendors in long-length time with low concentration exposure. Methodology: This paper reviewed published articles on biomarkers exposure, effects and susceptibility as the useful tools for benzene exposure assessment in the occupational and environmental setting. Data from previous epidemiological studies relevant to benzene exposure in various occupational and environmental setting is also summarized. Results: Based on these analyses, the findings agreed that these biomarkers are could suggest in linking the benzene exposure with possible adverse health effects. The biological monitoring used in epidemiological studies is useful in providing an understanding of activation and detoxification of benzene in both the occupational and general population as they are exposed to wide range of benzene concentration. Conclusion. The biomarkers of exposure, effects, and susceptibility utilized for benzene exposure assessment are valid tools in determining the greatest potential risk as well as an early biological effect which then caused a related specific disease.
benzene exposure ; biomarkers ; genetic polymorphisms and environmental and occupational population

Ionizing radiation is a well-known carcinogen, and is listed as one carcinogenic agent of occupational cancer. Given the increase in the number of workers exposed to radiation, as well as the increase in concern regarding occupational cancer, the number of radiation-related occupational cancer claims is expected to increase. Unlike exposure assessment of other carcinogenic agents in the workplace, such as asbestos and benzene, radiation exposure is usually assessed on an individual basis with personal dosimeters, which makes it feasible to assess whether a worker's cancer occurrence is associated with their individual exposure. However, given the absence of a threshold dose for cancer initiation, it remains difficult to identify radiation exposure as the root cause of occupational cancer. Moreover, the association between cancer and radiation exposure in the workplace has not been clearly established due to a lack of scientific evidence. Therefore, criteria for the recognition of radiation-related occupational cancer should be carefully reviewed and updated with new scientific evidence and social consensus. The current criteria in Korea are valid in terms of eligible radiogenic cancer sites, adequate latent period, assessment of radiation exposure, and probability of causation. However, reducing uncertainty with respect to the determination of causation between exposure and cancer and developing more specific criteria that considers mixed exposure to radiation and other carcinogenic agents remains an important open question.
Asbestos ; Benzene ; Consensus ; Humans ; Korea ; Radiation Exposure ; Radiation, Ionizing ; Uncertainty

OBJECTIVETo study the relationship between the polymorphism myeloperoxidase (MPO) gene and the genetic susceptibility to benzene toxicity in workers exposed to benzene and in patients with benzene poisoning.

METHODSUsing polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) techniques, the genotypes' polymorphism of MPO gene in 35 patients with chronic benzene poisoning, 46 workers exposed to benzene from the same workplace (as exposed control) and 26 controls were analyzed.

RESULTThere were three (G/G, G/A and A/A) genotypes in the region of 463 bp upstream of MPO gene. The distribution frequency in G/G wild-type genotype in patients was 27.4% more than that in the exposed workers. The risk of benzene-hematotoxicity in those with G/G genotype was 2.8-fold higher than G/A + A/A genotype (OR = 2.835, 95% CI: 1.065 - 7.549, P < 0.05). The polymorphism of myeloperoxidase was not associated with gender specific.

CONCLUSIONIn the same benzene-exposed environment, the subjects with MPO-463 G/G genotype may be more susceptible to benzene toxicity.

Adult ; Benzene ; poisoning ; Female ; Genotype ; Humans ; Male ; Occupational Exposure ; Peroxidase ; genetics ; Polymorphism, Genetic ; Risk

Adult ; Benzene ; adverse effects ; Hearing ; drug effects ; Humans ; Noise, Occupational ; adverse effects ; Occupational Exposure ; adverse effects

OBJECTIVETo explore the relevance between chronic benzene poisoning and ABO blood type.

METHODS1014 benzene-exposed workers chosen from Shanghai and 4196 non-benzene-exposed workers chosen from Yangpu district were accepted the ABO blood type identification, and two groups of workers compared with the Han population of Shanghai and China for the ABO blood type distribution; the 71 cases of chronic benzene poisoning were compared with the group of benzene-exposed workers for the ABO blood type distribution.

RESULTSThere were no significant differences of the ABO blood type distribution among the Han population of China, the Han population of Shanghai and the group of non-benzene-exposed workers (x(2)=7.95, P>0.05). The A type blood distribution frequency in the group of chronic benzene poisoning patients was 42.25%, significantly higher than the group of benzene-exposed workers (29.48%), and there was statistically significant difference (x(2)=5.11,P<0.05). The B type blood distribution frequency in the group of chronic benzene poisoning patients was 12.68% , significantly lower than the group of benzene-exposed workers (25.15%), and there was statistically significant difference (x(2)=5.61, Pbenzene poisoning patients and the group of benzene-exposed workers (P>0.05).

CONCLUSIONThe people with A type blood are susceptible to chronic benzene poisoning, however, the people with B type blood are not susceptible to chronic benzene poisoning.

ABO Blood-Group System ; genetics ; metabolism ; Benzene ; poisoning ; China ; Disease Susceptibility ; Female ; Humans ; Male ; Occupational Exposure