Blood Mercury Concentration and Related Factors in an Urban Coastal Area in Korea / 예방의학회지

OBJECTIVES: This study was carried out for the purpose of evaluating the blood mercury concentration of the residents of Busan, Korea, as well as the relationship between the mercury concentration and the pattern of fish consumption along with other epidemiological factors. METHODS: Two hundred ninety-three subjects (147 men and 146 women), who were aged 40 years or more, were recruited into this study between June and October 2009. The mean age of the subjects was 54.3 years (with a range of 40-70 years). Mercury concentrations in blood samples were measured using a gold-amalgam collection method. RESULTS: The geometric mean concentration of mercury in the total subjects was 8.63 microgram/L [range: 1.48~45.71 microgram/L]. The blood mercury concentration of the men (9.55 microgram/L) was significantly higher than that of the women (7.76 microgram/L). The blood mercury concentration of those who eat fish more than 4 times per week was higher than others, and was statistically significant (male p = 0.0019, female p = 0.0002). According to the multiple analysis, the blood mercury concentration was significantly affected by the consumed fish but other epidemiological factors were not related. CONCLUSIONS: It was found that the subjects who have consumed a large amount of fish may have high blood mercury concentration. It appears that fish consumption can influence blood mercury concentration. Therefore, guidelines for fish consumption that will decrease blood mercury concentration might be necessary in Korea.

The Prevalence of Asbestos Exposure-induced Pleural Thickening on Chest Radiograph in Repairing Shipyard Workers / 대한산업의학회지

OBJECTIVES: This study evaluated the prevalence of asbestos exposure-induced pleural thickening on chest radiograph in repairing shipyard workers. METHODS: A total of 2,114 incumbent and retired workers in a shipyard underwent chest radiograph, questionnaire study, interview, and physical exam from 2005 to 2007. Finally, 1,702 workers were selected and classified into two groups according to asbestos exposure: exposure and non-exposure groups. The characteristics in the exposure group were investigated. RESULTS: The prevalence of pleural thickening on chest radiograph was 5.2 % and 3.1 % in the exposure and non-exposure groups, respectively (p<0.05). In those aged 50 years or above, the prevalence was 17.6 % and 8.7 % in the exposure and non-exposure groups, respectively (p<0.05). The prevalence was 16.5 % and 30.2 % and the odds ratio was 2.34 (95% CI; 1.15-4.77) and 2.95 (95%CI; 1.08-8.07) in the workers with an exposure duration of 20-29 years and more than 30 years, respectively. The prevalence was higher when considering tuberculosis history. CONCLUSIONS: The prevalence was increased with increasing exposure duration was more than 20 years. The authors therefore suggest that this group should be followed up periodically by special program and that a longitudinal study with repairing shipyard workers as the cohort should be undertaken.

The Prevalence of Asbestos Exposure-induced Pleural Thickening on Chest Radiograph in Repairing Shipyard Workers / 대한산업의학회지

OBJECTIVES: This study evaluated the prevalence of asbestos exposure-induced pleural thickening on chest radiograph in repairing shipyard workers. METHODS: A total of 2,114 incumbent and retired workers in a shipyard underwent chest radiograph, questionnaire study, interview, and physical exam from 2005 to 2007. Finally, 1,702 workers were selected and classified into two groups according to asbestos exposure: exposure and non-exposure groups. The characteristics in the exposure group were investigated. RESULTS: The prevalence of pleural thickening on chest radiograph was 5.2 % and 3.1 % in the exposure and non-exposure groups, respectively (p<0.05). In those aged 50 years or above, the prevalence was 17.6 % and 8.7 % in the exposure and non-exposure groups, respectively (p<0.05). The prevalence was 16.5 % and 30.2 % and the odds ratio was 2.34 (95% CI; 1.15-4.77) and 2.95 (95%CI; 1.08-8.07) in the workers with an exposure duration of 20-29 years and more than 30 years, respectively. The prevalence was higher when considering tuberculosis history. CONCLUSIONS: The prevalence was increased with increasing exposure duration was more than 20 years. The authors therefore suggest that this group should be followed up periodically by special program and that a longitudinal study with repairing shipyard workers as the cohort should be undertaken.

Mercury Concentrations of Maternal and Umbilical Cord Blood in Korean Pregnant Women: Preliminary Study / 대한산업의학회지

OBJECTIVES: To evaluate the level of maternal and prenatal mercury exposure and to analyze the related factors. METHODS: Fifty-nine pregnant women were recruited into this study after obtaining informed consent. Samples were collected at delivery from normal pregnant women who were living in the city of Busan, Korea. Mercury concentrations in maternal and umbilical cord blood samples were measured using a gold-amalgam collection method. The total and methyl mercury levels of 36 of the 59 pregnant women were analyzed after randomization, and the results were compared. RESULTS: The mean total mercury concentration was 3.16+/-1.21 ppb and 5.43+/-2.22 ppb in maternal and cord blood, respectively. The average, maternal blood mercury level was lower than the prescribed toxic limit for human (WHO, 5 ppb), whereas the cord blood mercury was higher. The mercury exposure level exceeded the WHO recommendation in 5 (8.47%) cases of maternal blood and 29 of (49.15%) cord blood. There was a significant correlation between maternal and cord blood mercury concentrations. Total mercury and methyl mercury concentrations of the 36 random pregnant women were 3.06+/-1.17 ppb, and 2.60+/-1.11 ppb in maternal blood, and 5.20+/-2.36 ppb, and 4.70+/-1.97 ppb in cord blood, respectively. Methyl mercury accounted for 85.0% of the total mercury in maternal blood and 90.4% in cord blood. There was a significant correlation between total and methyl mercury concentrations. CONCLUSIONS: The study results suggest that mercury concentrations of cord blood may be regarded as indicative of high prenatal mercury exposure. Therefore, further studies are necessary to explain the cause of high mercury concentrations in cord blood, and to examine its relationship with various health indices.

Hypermethylation of p16(INK4a) in Korean Non-small Cell Lung Cancer Patients

Promoter hypermethylation of the p16(INK4a) gene was investigated in 81 sets of samples of tumor tissue and adjacent normal tissue from Korean patients with primary lung cancer, using the modified real-time polymerase chain reaction (PCR)/ SYBR Green detection method. The results showed hypermethylation of p16(INK4a) in 27.2% of tumor tissues, and in 11.1% of adjacent normal tissue. No significant association was found between the overall aberrant methylation in tumor and corresponding normal specimens (r=0.137, p=0.219). In 22 cases with p16(INK4a) hypermethylation in tumor tissues, only 4 (18.1%) cases were found to have a hypermethylated normal tissue specimen. The findings of this study show that smoking can influence the methylation level of the promoter region of p16(INK4a), and that this occurs in tumor tissues more frequently than in normal tissues. Other clinicopathological characteristics, including age, sex, tumor stage, and histologic type were not found to be correlated with p16(INK4a) methylation.

Disability Duration in Musculoskeletal Injured Patients due to Automobile Accidents

OBJECTIVE: The aims of this study were to refer descriptive statistics of the disability duration in musculoskeletal injured patients in the automobile accidents. METHOD: The authors chose 469,319 injured patients in traffic accidents as subjects that met inclusion criteria with 8 representative Abbreviated Injury Scale (AIS) comparable with 4th edition of Korean standard classification of diseases. Mean, standard deviation, mode, median, maximum and minimum of 8 representative AIS code were calculated. RESULTS: Mean disability duration for minor cervical sprain was 18.8 days, that of moderate cervical disc herniation was 56.2 days, that of serious cervical disc herniation was 141.5 days, that of minor lumbar sprain was 21.2 days, that of moderate lumbar disc herniation was 53.5 days, that of serious lumbar disc herniation was 128.1 days, that of sprain of 3 major joint in lower limb without desmorrhexis was 24.0 days, and that of dislocation or desmorrhexis of 3 major joint in lower limb was 101.2 days. CONCLUSION: Disability duration of the representative musculoskeletal diseases comparable to AIS code in 4th edition of Korean standard classification of diseases was presented and this study can be utilized as a basic recommended disability duration of automobile injured persons.

Characteristics of Disability Recuperation Musculoskeletal Diseases at a Ship-Yard

OBJECTIVE: This study was performed to analyze the length of work-related musculoskeletal disability and to identify the various related factors of disability duration. METHOD: Approved cases work-related musculoskeletal disease between Jan 1, 2000 and Jan 6, 2004 were collected by using the workers' compensation company's database and questionnaire. The cases were comprised of 16 more frequent musculoskeletal diseases. 551 approved musculoskeletal disease cases were composed of 295 recuperated cases and 256 recuperating cases. RESULTS: The average length of work-related musculoskele- tal disability were 420.3+/-246.2 day in the recuperated group and 428.0+/-328.9 day in the recuperating group. The mean disability length of musculoskeletal diseases were over one year with similar distribution except for ganglion. The length of disability were not affected by age, employment duration, type and number of co-mobidity, time from claim receipt to allowance, type of treatment. But, operation history and accident type were affected to the length of disability. CONCLUSION: The results suggest that the length of work- related musculoskeletal disability was not determined by biomedical disease related factors, however, it determined by social and social insurance systemic factors.

Imaging Findings among Retired Workers Who Were Long-term Exposed to Asbestos : Lung and Pleural Diseases Prevalence on Chest Radiograph and HRCT / 대한산업의학회지

PURPOSE: To determine imaging findings among retired workers who were long-term exposed to asbestos. Lung and pleural diseases prevalence were studied on chest radiograph and HRCT. MATERIALS AND METHODS: Eighteen workers who were long-term exposedto asbestos occupationally in shipyards were examined by chest radiographs (PA and lateral view) and HRCT (high-resolution computed tomography). RESULTS: In 12 of 18 subjects (66.7%), asbestos-related pleural abnormalities were evident in diaphragmatic, lateral chest wall and costophrenic angle of the pleura on chest radiographs. The thickness of pleural plaques at the lateral chest wall varied. Diffuse pleural thickening was evident in 2 workers. Parenchymal abnormalities were not found on chest radiographs. On HRCT, pleural thickening wasobserved in 16 of 18 subjects (88.9%), in the areas of juxtavertebral, diaphragmatic, anterior, lateral, mediastinal and fissural pleura. Curvilinear subpleural lines representing early parenchymal asbestosis were found in the lower posterior lung in three of 18 subjects (16.7%). CONCLUSIONS: In long term asbestos-exposed workers, the asbestos-related pleural disease was 66.7% on chest radiographs and 88.9% on HRCT. The authors suggest that this group should be followed up periodically

Usefulness of High Resolution Computed Tomography (HRCT) in the Diagnosis of Asbestos-Related Lung Diseases / 대한산업의학회지

OBJECTIVES: This study was carried out to improve the medical surveillance program of workers exposed to asbestos by examining the usefulness of High Resolution Computed Tomography (HRCT) in the diagnosis of asbestos-related lung disease. METHODS: The study subjects comprised 162 workers in a ship-repairing yard, 68 of whom had been directly exposed to asbestos and 94 indirectly exposed. The 'Occupational Safety & Health Administration (OSHA) asbestos standard, medical surveillance program' and HRCT were conducted to analyze the aspects of the asbestos-related lung disease. The OSHA asbestos standard, medical surveillance program consists of simple chest x-ray, spirometry and medical questionnaire. RESULTS: Seventeen (10.5%) of the 162 subjects, 10 (14.7%) directly exposed and 7 (7.4%) indirectly exposed, revealed asbestos-related lung disease on HRCT. The sensitivity and specificity of simple chest x-ray for asbestos-related lung disease were 70.6% and 98.6%, and the positive and negative predictive values were 85.7% and 96.6% respectively, as compared with HRCT. HRCT was an effective diagnostic tool especially to detect early asbestos-related lung disease. The study results indicated a relative significant association between the results of spirometry and HRCT. The variables significantly associated with asbestos-related lung disease on HRCT were work duration, smoking history (pack-years), past history of respiratory disease, cough and dyspnea. CONCLUSIONS: In the diagnosis of asbestos-related lung disease, HRCT should be considered not only for workers with positive findings on simple chest x-ray, but also workers with specific findings on spirometry, occupational history, smoking history, and past history of respiratory disease, or with respiratory symptoms such as cough and dyspnea.

Epidemiologic Characteristics of Occupational Lung Cancer in the Busan area / 대한산업의학회지

OBJECTIVES: The objectives of this study were to estimate the proportion of occupational lung cancer in the Busan area. METHODS: Occupational physicians of four university hospitals operating an occupational disease surveillance system in the Busan area actively interviewed all of the newly diagnosed, lung cancer cases about their characteristics and occupational histories through a survey questionnaire and chart review. To evaluate and agree on the work-relativity, the cases were presented in periodic meetings. RESULTS: A total of 301 lung cancer cases were interviewed, of which 50 (16.6%, all male, 27 probable and 23 possible) were related to occupational exposure. The exposure materials were asbestos, Cr, PAH etc. Pathologic findings included squamous cell carcinoma, adenocarcinoma and small cell carcinoma. CONCLUSIONS:The proportion of occupational lung cancer cases above the probable level was 9% and above the possible level was 17%. To develop the public health policy and to prevent further cancer death, the meaningful data from occupational cancer surveillance systems should be collected continuously for ongoing monitoring.

AnAnalysis of the Length of Admission for Some Musculoskeletal Disordersamong the National Health Insurance Corporation Data / 대한정형외과학회잡지

PURPOSE :The goals of this study were to investigate the medical care utilization and statistics of lengths of admissions such as the means, modes, medians, maximums, and minimums for patients with some musculoskeletal diseases among the National Health Insurance Corporation data. We provided basic recommendations for the proper lengths of admissions of occupationally injured workers with these diseases in Korea. METERIALS AND METHODS: The study subjects were 20 to 59 year-old patients who were admitted from January 1, 2000 to June 30, 2001, over 4-day lengths of admission for the management of 20 different musculoskeletal disorders. We calculated means, standard deviations, modes, medians, maximums, minimums, and points of inflection for the lengths of admission of patients with these disorders. RESULTS: The mean length of admission for carpal tunnel syndrome was 8.0+/-6.2 days, that of Raynaud's syndrome was 10.5+/-7.7 days, that of internal derangements of the knee was 12.9+/-11.8 days, that of unspecified internal derangements of the knee was 13.3+/-13.0 days, that of cervical disc disorder with radiculopathy was 16.8+/-19.0 days, that of other cervical disc displacements was 15.9+/-15.9 days, that of lumbar and other intervertebral disc disorders with radiculopathy was 14.9 +/-13.8 days, that of unspecified intervertebral disc displacements was 14.9+/-13.9 days, that of unspecified synovitis and tenosynovitis was 12.5+/-9.9 days, that of ganglions was 7.5+/-7.3 days, that of fasciitis, NEC, was 19.8+/-24.7 days, that of adhesive capsulitis of the shoulder was 15.2+/-15.5 days, that of impingement syndrome of the shoulder was 11.4+/-12.0 days, that of medial epicondylitis was 11.2+/-7.3 days, that of lateral epicondylitis was 12.1+/-11.5 days, that of myalgias was 12.4+/-19.5 days, that of sprain and strain of the cervical spine was 12.4+/-10.2 days, that of sprain and strain of the lumbar spine was 12.3+/-10.9 days, that of a current tear of the meniscus was 13.3+/-13.2 days, and that of sprain and strain involving the cruciate ligaments of the knee was 18.2+/-17.0 days. Every point of inflection was the 80th percentile or the 90th percentile of the lengths of admission of the subjects. CONCLUSION: This study has significant weaknesses, such as limitations of applicable ranges and errors in the National Health Insurance Corporation data, among others. However, the authors present various statistics and points of inflection of lengths of admissions for patients suffering from 20 work-related musculoskeletal disorders in the general population. Those cases in which the lengths of admissions of patients with the above-mentioned musculoskeletal disorders that are greater than the points of inflection, need to be evaluated carefully.

Factors Affecting Fatigue and Stress in Male Manufacturing Workers / 대한산업의학회지

OBJECTIVES: The aims of this study were to investigate the factors affecting the fatigue and stress in male manufacturing workers. METHODS: A questionnaire investigating general characteristics, lifestyle factors, job characteristics, fatigue and stress was distributed to 896 subjects. From 851 respondents, 11 responses with insufficient data were excluded. The data were analyzed to investigate the factors affecting personal fatigue and stress. RESULTS: Among the general characteristics, both fatigue and stress in the older group were significantly lower than in the younger group (p<0.05). Fatigue in the group with higher education was significantly higher than in the group with only high school education (p<0.05). The group who lived alone had significantly more stress (p<0.05). Among lifestyle factors, people who exercised regularly had significantly lower fatigue and stress than those who did not (p<0.05). Fatigue was negatively correlated with decision latitude, supervisor support, and coworker support. Stress was positively correlated with job demand and negatively correlated with decision latitude, supervisor support, and coworker support. Fatigue and stress were positively correlated with each other. Multiple linear regression analysis showed that among job characteristic factors, coworker support affected fatigue while job demand and supervisor support affected stress. CONCLUSIONS: Fatigue and stress were positively correlated, but the job characteristics that affected each were different. This suggests that for effective management of fatigue and stress, the details of job characteristics need to be considered individually for the intervention and prevention of fatigue and stress.

A Case of Lung Cancer Caused by Long-Term Asbestos Exposure / 대한산업의학회지

OBJECTIVES: To report a case of lung cancer caused by long-term asbestos exposure in a shipyard. METHODS: We evaluated chest X-ray, pulmonary function test, and chest CT and analyzed asbestos concentration in the lung tissue and bulk sample from the workplace. We also performed a workplace survey. RESULTS: The patient had worked at the shipyard for 31 years. The biopsy samples were processed to determine the asbestos content in the lung tissue and bulk sample using a transmission electron microscope (TEM) equipped with an energy dispersive X-ray analyzer (EDX). The TEM-EDX analysis revealed many asbestos fibers, the majority of which were amosite. In addition, the concentration asbestos fibers in the workplace exceeded the occupational exposure limits of asbestos. CONCLUSIONS: Our findings strongly suggest that this patient's lung cancer was related to the long-term asbestos exposure.

Prevalence of Metabolic Syndrome and Waist Circumference Estimation in Some Korean Adults / 예방의학회지

OBJECTIVE: The purpose of this study was to estimate the prevalence of metabolic syndrome, as defined by the ATP III report, in some Korean adults and use the Asian-Pacific proposed waist circumference to investigate waist circumference in some Korean adults using ROC curves. METHODS: Study subjects were seventy-five thousands and ninety one persons (47, 979 men and 27, 111 women) who were selected among the patients who visited hospital for health evaluation from January 2000 to December 2001. All subjects were measured by height, weight, waist and hip circumferences, blood pressure and blood chemistry (lipid profile). RESULTS: The mean age was 41.6+/-8.5 years in men, 41.1+/-10.4 years in women (p< 0.05). Body mass index was in the normal range in 35.3% of men, and 55.9% of women. In both men and women, blood pressure, blood sugar, total cholesterol and triglyceride were positively correlated with BMI. waist circumference, and Broca's index (p< 0.01). However HDL. choloesterol was correlated negatively (p< 0.01). Using ROC curve, the calculated waist circumferences were 84 cm in men (sensitivity 61.4% and specificity 64.1%) and 74 cm in women (sensitivity 65.0% and specificity 73.2%). The age adjusted prevalences of the metabolic syndrome as defined by NCEP ATP III were different for men (6.4%) and women (14.6%). The prevalence increased from 1.2% among participants aged 20 through 29years to 15.0% among participants aged over 60years in men (p< 0.05) and from 1.6% to 27.4% respectively, in women. The age adjusted prevalences, as defined by using the waist circumference that was recommended by WHO's regional office for the western Pacific, were 10.6% in men and 18.5% in women. The age adjusted prevalences, as defined by using the waist circumference that was calculated by the ROC curves, were 17.1% in men and 22.4% in women. And All prevalences were increased following increased BMI and Broca's index. CONCLUSIONS: The prevalence of metabolic syndrome in some Korean adults was lower than that in western adults. Nevertheless because waist circumference was differed among race and region, application of the same criteria was not proper. Morcover, a higher awareness was required in women, because the prevalence of metabolic syndrome was rapidly increased with increment of age.

Occupational disease surveillance system in Busan, Ulsan, Kyung-Nam area / 대한산업의학회지

OBJECTIVE: Occupational medicine specialists in the Busan, Ulsan and Kyung-Nam areas established an area-based occupational disease surveillance system and used this system to collected case information for the purpose of preventing occupational diseases METHODS: 11 hospitals participated in this system. The authors selected five main diseases, which were hand-arm vibration syndrome (HAVS), work-related musculoskeletal disorder (WRMSD), occupational asthma, occupational skin disease and occupational lung cancer and established their case definitions. All cases were reported on the web, and real time analysis was conducted. RESULTS: Between Apri1 2001 and April 2003, 192 cases of HAVS, 118 cases of WRMSD, 33 cases of occupational asthma, 17 cases of occupational skin disease and 17 cases of occupational lung cancer (for a total of 377 cases of these five main diseases) were reported. Most of the HAVS cases came from shipbuilding, and 172 of them (92.7 %) were associated with grinding. Of the four main types of WRMSD, carpal tunnel syndrome (CTS) was the most prevalent with 46 cases and shipbuilding was also the main industry involved (83.9 %). The ergonomic risk factors involved mainly associated with the hand. In 19 (57.6 %) and 4 (12.1 %) cases of occupational asthma, the agents included isocyanate and welding fume, respectively. 64.7 % of the cases of occupational skin diseases were contact dermatitis, and organic solvents and welding fume were the main agents involved. The causative agents of occupational lung cancer included Cr, welding fume, PAH, Ni, etc. 10 (58.8 %) of the cases were diagnosed as squamous cell carcinoma and 5 (29.4 %) as adenoma. CONCLUSION: This result showed that an area-based occupational disease surveillance system might provide an effective method of evaluating the prevalence of such diseases, however the Busan, Ulsan and Kyung-Nam provinces are too large to be treated as individual areas. Therefore, the authors suggest that each province should establish its own surveillance system.

The C677 Mutation in Methylene Tetrahydrofolate Reductase Gene: Correlation with Uric Acid and Cardiovascular Risk Factors in Elderly Korean men

The C677T mutation in the methylene tetrahydrofolate reductase (MTHFR) gene results in elevated homocysteine levels and, presumably, in increased cardiovascular risk. Moreover, elevated homocysteine levels are reportedly associated with high serum uric acid levels. We evaluated the MTHFR genotype and a panel of biochemical, hematological variables, and lifestyle characteristics in 327 elderly Korean men (age range 40-81 yr; mean, 51.87). This study shows that mutation of the MTHFR gene may be a risk for hyperuricemia. The mean uric acid levels for the C/C, C/T and T/T genotypes were 5.54, 5.91 and 6.33 mg/dL, respectively (p=0.000). The T/T genotype was significantly more frequent in subjects with high uric acid levels (p=0.003). Thus, this mutation of the MTHFR gene is implied by the study results to be a risk factor of hyperuricemia in elderly Korean men. However, the relationship between the MTHFR mutation and uric acid metabolism remains unclear. Therefore, further studies are necessary to explain the associated between the MTHFR mutation and elevated uric acid levels, and to examine potential relationships between it and conventional cardiovascular risk factors.

Effects of Health on Shift-Work: General and Psychological health, Sleep, Stress, Quality of life / 대한산업의학회지

OBJECTIVES: This study was performed to investigate the effects of shift-work, in terms of general health concepts, insomnia, stress, quality of life and psychological health, at several manufacturing plants. METHODS: Questionnaires were distributed to 850 shift-workers (study group), and to 550 non-shift workers (as a control group). The questionnaires included questions on ; general health concepts, insomnia, stress, quality of life and psychological health. 455 shift-workers and 372 non-shift workers completed the questionnaires, and the factors influencing the health status and quality of life in workers estimated by multiple iogistic regression analysis. RESULTS: From the general health questionnaires, the mental health and health perception were significantly different between the shift and non-shift workers, with the better being former than the latter (p<0.05). Shift-workers complained of more insomnia when adjusted for age, working period, education and job satisfaction. Greater job satisfaction, was coupled with less complaints of insomnia (p<0.05). There were 200(43.96 %) shift workers classified as insomniac, whereas with the non-shift workers this figure was 84 (25.15 %), showing a significant difference between the two groups (p<0.05). Shift-workers were more stressed than the non-shift workers in their daily lives, which also showed significant difference (p<0.05). Less job satisfaction, was coupled with more complaints of stress (p<0.05). The quality of life of the shift-workers was lower than that of the nonshift workers (p<0.05). With the shift-workers complaining of more anxiety than the nonshift workers (p<0.05). CONCLUSIONS: Our results suggest that shift-workers suffer from physical and psychological distresses, sleep problems and stress than non-shift workers. Furthermore, it is presumed that these factors might negatively affect the quality of life of shift-workers. Accordingly, interventional methods for shift-worker's health and quality of life as a result of adverse effects of shift-work are needed.

Aluminum Clearance by Hemodialysis in Chronic Renal Failure / 대한산업의학회지

OBJECTIVES: This study was carried out to investigate aluminum levels in blood and the factors affecting aluminum concentration; we also presented findings on aluminum clearance during hemodialysis in chronic renal failure patients. METHODS: We selected 56 patients with case of chronic renal failure and 144 healthy examinees as a control group. We analysed aluminum concentrations in their blood, water and dialysis fluid. RESULTS: The blood aluminum concentration in the 56 patients was 2.38+/-0.27 microgram/ dL , about 4 times higher than that of the control group (p < 0.01). Blood aluminum concentrations were not affected by factors such as creatinine, BUN, hemodialysis duration, iron, and drinking water. After hemodialysis, blood aluminum level were decreased by about 15% and the aluminum concentration in the dialysis fluid was increased. CONCLUSIONS: Blood aluminum levels were significantly high in the chronic renal failure patients; and hemodialysis helped the patients to excrete aluminum. Authors suggest that a purified dialysis fluid containing a lower aluminum concentration would facilitate aluminum excretion in hemodialysis patients.

The Relationship between Cold-Exposure and Hypertension / 대한산업의학회지

OBJECTIVES: This study was carried out to suggest preventive methods for hypertension in cold-exposed workers. METHODS: In 11 refrigeration industries, 68 workers working in refrigerated areas more than one time per day were selected as the exposed group, and 68 workers not exposed to cold were selected as the control group. We interviewed the subjects with a questionnaire covering occupational history, and conducted clinical and laboratory tests including measurements of blood pressure and core temperature. RESULTS: The systolic blood pressure in the exposed group(130.0+/-13.3 mmHg) was significantly higher than that recorded in the control group(118.3+/-12.1 mmHg), as was the diastolic blood pressure in the exposed group(82.7+/-8.5 mmHg) versus the control group(77.4 +/-8.7 mmHg). The core temperature in the exposed group(36.1+/-0 . 7degrees C) was significantly lower than that experienced in the control group(36.4+/-0 . 5degrees C). In logistic regression analysis, age, cold exposure severity and milk intake were significant variables, with odds ratios of 5.204(95 % CI 1.440~18.812), 2.674(95 % CI 1.080~6.618), and 0.364(95 % CI 0.141~0.942), respectively. CONCLUSIONS: Our study suggests that cold-exposed workers have higher a higher risk of hypertension, and that their core temperature is lower. Risk factors affecting hypertension of cold-exposed workers include age, cold exposure severity and milk intake. For the prevention of hypertension, cold-exposed workers should minimize cold-exposure time as much as possible.

Survey on the Prevalence of Carpal Tunnel Syndrome in Simple Repetitive Workers Who Use Upper Extremities / 대한산업의학회지

OBJECTIVES: This study was carried out to survey on the prevalence of Carpal Tunnel Syndrome(CTS) in high risk jobs(meat and fish processing plant and wood plant), by application of Nerve Conduction Study(NCS), a confirmatory diagnostic method. METHODS: Experimental group was 69 workers sampled from meat and fish processing plants and 17 workers sampled from wood plants, who were simple, repetitive workers using upper extremities and control group was 28 workers sampled from managers, secretaries and keepers. All employees were examined through work history, physical examination and NCS. RESULTS: 18 workers(26.09%) in meat and fish processing plants, and 5 workers(29.41%) in wood plants had compatible findings to NIOSH diagnostic criteria for CTS. The experimental group had more symptoms(complaint of upper extremities, Visual Analogue Scale >or= 4(VAS: total 10 point)), signs(Tinel and Phalen test) and prevalence of CTS than control group ( por=7 years). CONCLUSIONS: The prevalence of CTS in meat and fish processing plant and wood plant were 26.09% and 29.41% respectively. Authors propose that meat and fish processing and wood plants should be managed as a risk job category which were designated by OSHA in 1996