1.Health Effect of Dioxin.
Korean Journal of Preventive Medicine 2003;36(4):323-324
No abstract available.
2.Three cases of occupational asthma induced by urethane paint.
Byung Soon CHOI ; Hae Kwan CHEONG
Korean Journal of Occupational and Environmental Medicine 1992;4(2):212-220
No abstract available.
Asthma, Occupational*
;
Paint*
;
Urethane*
3.Significance of Brain Magnetic Resonance Imaging (MRI) in the Assessment of Occupational Manganese Exposure.
Hae Kwan CHEONG ; Myung Ah LIM ; Kee Hyun CHANG
Journal of the Korean Society of Magnetic Resonance in Medicine 1998;2(1):14-30
Manganese is an essential element in the body. It is mainly diposited in the liver and to a lesser degree in the basal ganglia of the brain and eliminated through the bile duct. Rapid turnover of manganese in the body makes it difficult to evaluate the manganese exposure in worker, especially in those with irregular or intermittent exposure, like welder. Therefore, conventional biomarkers, including blood and urine manganese can provide only a limited information about the long-term or cumulative exposure to manganese. Introduction of magnetic resonance imaging (MRI) made a progress in the assessment of manganese exposure in the medical conditions related to manganese aculmulation, e. g., relaxation time on MRI due to its paramagnetic property, resulting in high signal intensity(HSI) on T1-weighted image(T1WI) of MRI. Manganese deposition int he brain, therefore, can be visualized as an HSI in the globus pallidus, the substantia nigra, the putamen and the pituitary. Clinical and epidemiologic studies regarding the MRI findings in the cases of occupational and non-occupational manganese exposure were reviewed. Relationships between HSI on T1WI of MRI and age, gender, occupational manganese exposure, and neurological dysfunction were analysed. Relationship between biological exposure indices and HSI on MRI were also reviewed. Literatures were reviewed to establish the relationships between HSI, manganese deposition in the brain, pathologic findings, and neurological dysfunction. HSI on T1WI of MRI reflects regional manganese deposition in the brain. This relationship enables an estimation of regional manganese deposition in the brain by analysing MR signal intensity. Manganese deposition in the brain can induce a neuronal loss in the basal ganglia but functional abnormality is supposed to be related to the cumulative exposure of manganese is relatively too short to reflect the long-term cumulative exposure of manganese in the brain, use of brain MRI for the assessment of exposure in a group of workers seems to be hardly rationalized, while it can be a useful adjunct for the evaluation of manganese exposure in the cases with suspected manganese-related health problems.
Basal Ganglia
;
Bile Ducts
;
Biomarkers
;
Brain*
;
Epidemiologic Studies
;
Globus Pallidus
;
Liver
;
Magnetic Resonance Imaging*
;
Manganese*
;
Neurons
;
Putamen
;
Relaxation
;
Substantia Nigra
4.A study on the status of management among workers diagnosed as hearing loss in an iron foundry.
Hyun Sul LIM ; Heon KIM ; Hae Kwan CHEONG
Korean Journal of Occupational and Environmental Medicine 1992;4(2):190-198
No abstract available.
Hearing Loss*
;
Hearing*
;
Iron*
5.Evaluation of Early Neurologic Abnormalities on the Workers Exposed to Acrylamide.
Seong Soon KIM ; Hae Kwan CHEONG ; Yong Wook KWON
Korean Journal of Occupational and Environmental Medicine 2000;12(3):367-383
OBJECTIVES: Acrylamide is a neurotoxin inducing central-peripheral distal axonopathy. The authors evaluated several neurologic tests to screen the early effect of occupational acrylamide exposure. METHODS: Fifty-two males working either in the production of acrylamide monomer or in the handling of acrylamide in Ulsan, Korea, were selected and subcategorized into the high-exposure group (n=10, mean age of 30. 4 years) and the low-exposure group (n=42, mean age of 28.9 years). Twenty-three males (mean age 29.4 years) from medical professionals and students were chosen as a non-exposed reference group. Symptom questionnaire, neurologic examination, electrodiagnostic test, vibrotactile threshold test, and Lanthony desaturated 15 panel test (LD-15D) were done. RESULTS: The high-exposure group showed more number of specific symptoms on questionnaire and more abnormal two point discrimination test. High-exposure group showed a significant difference in the median motor conduction velocity, peroneal nerve motor latency, sensory amplitude of median nerve action potential, and sensory latency of sural nerve. The vibrotactile threshold of the high-exposure group was significantly higher in both hands and feet than that of the low-exposure group and the reference group. Average color confusion index on the LD-15D was significantly higher in the high-exposure group (median 22.7, range 0-135.7) than in the reference group (median 2.4, range 0-33.2). CONCLUSIONS: The symptom questionnaire, vibrotactile threshold test, and color discrimination test are sensitive in detection of the early acrylamide-induced neuropathy, and the combination of these tests would further facilitate the effectiveness of the screening.
Acrylamide*
;
Action Potentials
;
Discrimination (Psychology)
;
Foot
;
Hand
;
Humans
;
Korea
;
Male
;
Mass Screening
;
Median Nerve
;
Neurologic Examination
;
Peroneal Nerve
;
Questionnaires
;
Sural Nerve
;
Ulsan
6.A Study on the Manganese Exposure and Health Hazard among Manganese Manufacturing Woman Workers.
Hyun Sul LIM ; Ji Yong KIM ; Hae Kwan CHEONG ; Hoe Kyung CHEONG
Korean Journal of Preventive Medicine 1995;28(2):406-420
No abstract available.
Female
;
Humans
;
Manganese*
7.Relationship between the Serum CPK and the Shoulder Muscle Disorder in VDT Workers.
Soo Keun KIM ; Hae Kwan CHEONG
Korean Journal of Occupational and Environmental Medicine 1998;10(2):172-179
VDT workers are often exposed to static load in the shoulder stabilizing muscle due to repetitive work over long periods. Many investigations were reported the relationships between static load due to repetitive work and regional muscle disorder. However, diagnostic approach to work-related muscle disorder is difficult due to the absence of objective diagnostic tools. This study was performed to investigate the relationship between the serum CPK (creatine phosphokinase) concentrations and the shoulder muscle disorders. Results are as follow. 1. Mean serum CPK in total VDT workers was 67.6+/-28.4 IU/l and workers with abnormal serum CPK were 35 (21.5%). 2. Comparison between cases and controls did not show significant difference in the serum CPK level and the distribution of abnormal findings. 3. Sensitivity and specificity of the CPK test was 23.0% and 82.0%, respectively. Above results, in accordance with literatures, show that while serum CPK measure menu can be useful for the diagnosis of acute muscle injury, it does not adequately reflect the muscle disorders developed by the repetitive work of low tension over long time, such as VDT works.
Diagnosis
;
Muscular Diseases*
;
Sensitivity and Specificity
;
Shoulder*
8.A Study on the Pervalence and Risk Factors of Liver Dysfunction among the Workers in Chemical Factors.
Hae Kwan CHEONG ; Joung Soom KIM
Korean Journal of Preventive Medicine 1997;30(1):103-128
The object of this study is to evaluate the possibility of chemical-induced liver disorder among workers exposed to various chemicals and to classify the the liver function abnormalities by causes and to analyse the risk factors for each liver disorders. A cross-sectional study including questionnaire survey, physical examination, laboratory tests and ultrasonography of liver was conducted on 1,126 workers, 459 workers in a coal chemical plant(company A) and 667 workers in an insulation material manufacturing factory(company B). An industrial hygienist reviewed the chemicals used in both companies and evaluated the work environments to classify the workers by chemical exposure semiquantitatively. The results are as follows; 1. Of 459 workers in company A, 83 workers(18.1 %) are classified as nonexposed, 163(35.5%) as short-term exposure group, 155(33.8 %) as intermediately exposed group and 58(12.6 %) as long-term exposed group based on the mean daily exposure to hepatotoxic chemicals evaluated by an industrial hygienist. Of 667 workers in company B, 484(72.6 %) workers were classified as nonexposed and 183(35.5 %) as exposed. 2. Workers with SGOT level higher than 40 IU/l were 46(10.0 %) in company A and 77(11.5 %) in company B, and those with SGPT level higher than 35 IU/l were 118(25.7 %) in company A and 198(29.7 %) in company B. The differences were not significant between companies and between exposure groups(p>0.05). Workers with ?-GT level higher than 62 IU/l were 29(6.3 %) in company A and 77(11.5 %) in company B(p<0.01). The difference between exposure groups was not significant(p>0.05) within companies. Workers with liver function abnormalities(defined as SGOT higher than 40 IU/l or SGPT higher than 35 IU/l, Ministry of Labor, 1989) were 338(30.0 %) among 1,126 workers. Of 338 workers with liver function abnormalities 139(12.3 %) had fatty liver by ultrasonography, 79(7.0 %) had alcoholic liver(defined as workers with liver function abnormalities with weekly alcohol consumption greater than 280 g for more than 5 years), 54(4.8 %) had hepatitis B, 12(1.1 %) had hepatitis C and the other 114(33.7 %) was not otherwise classified. Prevalences of alcoholic liver and fatty liver were significantly lower in company A(prevalence ratio 0.24 for alcoholic liver, p<0.001; prevalence ratio 0.76 for fatty liver, p<0.05) but prevalences of liver disorders between exposure groups within companies were not significant(p>0.05). 3. Summary prevalence ratios(SPR) of liver function abnormalities, fatty liver and other liver disorders, adjusted by age and company were not significantly higher in exposed group in any chemicals(p>0.05) but in some chemicals, SPRs were significantly lower. 4. On simple analysis of risk factors for liver function abnormalities, prevalence odds ratio(POR) of those with age between 30 and 39 was 1.54(p<0.01) and those with age over 40 was 1.51(p<0.01). POR of those with histories of liver disorders and general anesthesia was 1.77(p<0.001) and 4.02 for those with overweight and 6.23 for those with obesity, defined by body mass index(p<0.001). 5. On logistic regression analysis, risk factors of liver function abnormality were fatty liver(POR 2.92 for grade 1, 12.15 for grade 2), presence of hepatitis B surface antigen(POR 3.62) and obesity(POR 5.38 for overweight and 16.52 for obesity). Presence of hepatitis B surface antigen(POR 0.18) was the only preventive factor of fatty liver. Company(POR 0.30) and obesity(POR 2.49 for overweight, 4.52 for obesity) were related to the alcoholic liver. Obesity(POR 2.94 for overweight) was the only significant risk factor of hepatitis B and there was no significant risk factor for liver function abnormality not otherwise classified. It is concluded that the evidence of liver disorder related with chemical exposure is not evident in these factories. It is also postulated that fatty liver and alcoholic liver is most common causes of liver function abnormalities among workers and effort for weight control and improvement of life style should be done.
Alanine Transaminase
;
Alcohol Drinking
;
Alcoholics
;
Anesthesia, General
;
Aspartate Aminotransferases
;
Coal
;
Cross-Sectional Studies
;
Fatty Liver
;
Hepatitis B
;
Hepatitis C
;
Humans
;
Life Style
;
Liver Diseases*
;
Liver*
;
Logistic Models
;
Obesity
;
Overweight
;
Physical Examination
;
Prevalence
;
Surveys and Questionnaires
;
Risk Factors*
;
Ultrasonography
9.Talc Deposition in Lipoma: A Pathologic and Mineralogic Study.
Jung Ran KIM ; Hyun Sul LIM ; Hae Kwan CHEONG ; Ji Yong KIM ; Kiyoshi SAKAI ; Naomi HISANAGA
Korean Journal of Pathology 1999;33(11):1024-1032
Three cases of lipomas associated with heavy talc deposits are reported in local inhabitants near a fiber glass factory. Pathologic and mineralogical analysis by polarizing microscopy, scanning and transmission electron microscopy with energy dispersive X-ray analysis and X-ray diffraction of mass were done. Simultaneously, we performed an epidemiological survey and a mineralogical study of disposed fiber glass from waste site and ground water. All tumors consisted of mature fat tissue containing an abundant birefringent talc fibers and particles under polarized light. The concentrations of the fibers were 494.7, 6.7 and 50.7 million fibers per gram of dry tissue. The fibers were needlelike with rectangular fractured ends, up to 17 micrometer in length and 0.5 micrometer in diameter. EDX and X-ray diffraction analysis of the fibers showed that 71 to 100% of the fibers were magnesium silicate, talc. We also identified magnesium silicate fibers in the fiber glass from the waste site and in the ground water which were similar to talc fibers in lipomas,. We concluded that fibrous talc, a component of fiberglass waste, might be associated with the development of lipomas via unknown exposure route.
Environmental Exposure
;
Foreign Bodies
;
Glass
;
Groundwater
;
Lipoma*
;
Magnesium
;
Microscopy
;
Microscopy, Electron, Transmission
;
Nerve Fibers, Myelinated
;
Silicates
;
Talc*
;
X-Ray Diffraction
10.A Study on the Status of Preemployment Health Examination.
Hae Kwan CHEONG ; Hyun Sul LIM
Korean Journal of Occupational and Environmental Medicine 1995;7(2):332-346
Preemployment health examination, stipulated by the Occupational Safety and Health Regulations, plays an important role in workers' health management. Recently, employers are getting more aware of the importance of screening recruits before employment to decrease the development of occupational disorders and work loss due to health problems. Accordingly, additional test items are being included and selection criteria for preemployment health examination is getting more strict. However, studies and. data on preemployment health examination are scarce until now. Authors reviewed preemployment health certificates of 3,261 recruits issued by a university hospital in Pohang from January 3 to December 31, 1993, analyzed regulations on preemployment health examination of 16 companies in the Pohang area, and surveyed 80 health and safety personnel with questionnaire to evaluate the present status of preemployment health examination. Of 3,261 recruits 125 (3.8 %) failed to recruit. Main causes of. failure were chronic liver disease, tuberculosis of undetermined activity. The regulations of 16 companies on preemployment health examination were reviewed. Most companies adopted additional test items in addition to basic test items listed on the Regulation; test of physical strength, pulmonary function test, pure tone audiometer (2000 Hz and 4000 Hz in addition to 1000 Hz), exercise provocation test, urine erythrocyte and urobilinogen, complete blood count, stool examination, VDRL, arid sputum examination for acid fast bacilli In most companies, obesity, hearing disturbance, color vision disturbance was included in the selection criteria. Hepatitis B carrier was not accepted in 4 companies, accepted conditionally in 2, and accepted in 5 companies. Of 80 health and safety personnel of companies in the Pohang area, 56 (70. 0 %) perceived preemployment health examination as a tool for selection of recruits and 14(17.5%) as a procedure for job fitting. Most of them were against the acceptance of recruits with hepatitis B carrier, lumbar spine deformity, and hearing disturbance. In conclusion, preemployment health examination is performed mainly for the purpose of selection of healthier employee, but test items and selection creteria is not seem to be adequate. Authors suggest that further studies are needed to select the test items for specific job, and application of selection criteria be restricted only to some specified jobs. Consecutive filling of preemployment health examination to the periodic health examination was also suggested.
Blood Cell Count
;
Color Vision
;
Congenital Abnormalities
;
Employment
;
Erythrocytes
;
Gyeongsangbuk-do
;
Hearing
;
Hepatitis B
;
Liver Diseases
;
Mass Screening
;
Obesity
;
Occupational Health
;
Patient Selection
;
Questionnaires
;
Respiratory Function Tests
;
Social Control, Formal
;
Spine
;
Sputum
;
Tuberculosis
;
Urobilinogen