A Study on Karoshi to Make Application for Industrial Accident Compensation in Busan / 대한산업의학회지

OBJECTIVES: Karoshi is a word meaning death from work-overload. Work-related diseases due to continuous overwork are primarily cerebro- and cardio-vascular in nature. In Korea, despite an increase in the incidence of Karoshi, it is not easy to recognise by workmen's compensation in Korea. This study intended to establish basic information concerning the incidence of Karoshi. METHODS: 219 cases were collected based on workers' compensation records of three Busan Regional Centers of Labor Welfare Corporation from 1991 to 1999. The size of workplace, occupation, daily working time, type of working schedule, job tenures, characters of work-overload and duration of work-overload were investigated according of subgroups of general characteristics. Both univariate and multiple logistic regression analyses were used to estimate the relationship between risk factors and a recognition of Karoshi. RESULTS: 1. 61.6 % of total cases were recognized as Karoshi. 30.6 % occurred in a small workplace of less than 50 workers, 34.7 % were drivers or guards, and 48.8 % were more than 50 years old. Additionally, 29.6 % worked more than 12 hours, 37.5 % were irregular hours and shift workers and 21.5 % of the total had been on the job less than 6 months. 2. Of the causes of death, 49.8 % was cerebro-vascular diseases and it was more than cardio-vascular ones. And 80.4 % of total cases was belonged to the recognition-category of the Labour Ministry's Law. The previous disease history was found on 49.8 % of all cases. Of them, hypertension was most common as 21.9 %. 3. 53.9 % of patients were exposed to job hazards such as driving, monitoring, guarding, risky jobs and frequent long-term official trips. 64.7 % recorded a increased work-overload of job contents and working hours. Of the several types of work-overload, 42.5 % displayed long-term physical and psychotic work-overload and 22.2 % exhibited job characteristic work-overload. 4. In this study, work-overload was associated with the incidence of Karoshi in 76.3 % of cases. This rate was higher than the recognition of Workmen's compensation recorded by the Korea Labor Welfare Corporation. Of these, 43.6 % belonged to sufficient factors, 10.4 % partial factors, and 22.3 % were due to aggravating factors. 5. Logistic regression demonstrated that death due to cerebro- and cardio-vascular disease, shorttenure within 6 month was significantly associated with a recognition of Karoshi (p=0.034, OR=3.00, C I = 1 . 0 9~8.30/p=0.016, OR=6.76, CI=1.43~32.07 respectively) and that an increase of work-overload was also associated, but its statistical significance was slightly lower(p=0.081, OR=2.02, CI=0.91.~4.46 ) . However, no association was found between this recognition and overtime work, hazardous job, irregular work schedule, low-income, injury-onset place, or small size of workplace. The elderly group(>50years old) and those with a previous disease history were negatively associated with recognition although the statistical association was low. CONCLUSIONS: Karoshi in Busan occurred frequently in a small workplace of less than 50 workers, especially drivers or guards. Additionally, these cases worked more than 12 hours, were irregular hours and shift workers. The death due to cerebro- and cardio-vascular disease, short-tenure within 6 month was significantly associated with a recognition of Karoshi. However Karoshi in this study occurred frequently in overtime work and high risk groups of work-overload. Therefore, for prevention of Karoshi, work-overload and overtime work need improved and controled.

A Case of Chronic Methyl Bromide Poisoning Associated with Cerebellar Ataxia, Polyneuropathy and Optic Neuropathy

Methyl bromide is a commonly used fumigant to disinfect soil, grains, and warehouses. The accumulation of danger-ous concentrations can produce various neurotoxic effects in humans. A 45-year-old man, who had worked in the fumi-gation business, presented with polyneuropathy, optic neuropathy, and cerebellar sign, and serially sampled blood, urine and cerebrospinal fluid showed significant elevation of methyl bromide concentration. Regular education to workers and strict adherence to the safety precautions are needed to avoid the risk of toxicity associated with methyl bromide fumigation.

Utility of a Self-administered Hand Symptom Diagram for the Diagnosis of Carpal Tunnel Syndrome / 대한산업의학회지

OBJECTIVES: This study was conducted to compare a self-administered hand symptom diagram with other diagnostic tests and to assess its value in the diagnosis of carpal tunnel syndrome. METHODS: A self-administered hand symptom diagram has been developed for the evaluation of upper extremity paresthesias. A rating system was devised to classify the diagrams into four categories: classic, probable, possible, or unlikely carpal tunnel syndrome. Before nerve conduction testing, a medical history and demographic data were collected, a physical examination was conducted, and a hand symptom diagram was obtained from each patient. The diagram ratings of 85 patients(130 hands) were evaluated by an occupational and environmental medicine physician and a nerve conduction study was administered and interpreted by a rehabilitation medicine physician. RESULTS: Of 85 patients, 48(56.5 %) had carpal tunnel syndrome confirmed by nerve conduction study. A hand symptom diagram rating of classic or probable CTS had a sensitivity of 75.6 %, a specificity of 59.6 %, a positive predictive value of 73.8 % and a negative predictive value of 62.0 %. Of the combinations of clinical findings in carpal tunnel syndrome, a classic or probable hand symptom diagram or a positive Tinel's sign showed the highest sensitivity. CONCLUSIONS: A self-administered hand symptom diagram is valuable in the diagnosis of carpal tunnel syndrome among patients with upper extremity paresthesias. It is a useful diagnostic tool and may be valuable for occupational or population screening.

The Serum Copper and Zinc Concentration according to the Progression of Pneumoconiosis / 대한산업의학회지

OBJECTIVES: Copper and Zinc, the trace elements of a living body, take a part in immunologic mechanism and induce the pulmonary fibrosis which is the pathologic progress of pneumoconiosis. This study was performed to assist the identification of the pathologic process of pulmonary fibrosis in pneumoconiosis. METHODS: The subjects of this study was 200 diagnosed persons as pneumoconiosis, of whom 100 persons was the visitors in the outpatients departments of pneumoconiosis and 100 admissive pneumoconiosis patients. The serum copper and zinc are measured and com pared. RESULTS: The mean serum copper concentration of visitor group was significantly higher than that of control group, and that of stage V3 subgroup of visitor group was highest because of their advanced fibrosis. But, there was not the difference of serum copper concentration between patient and control group. We thought that the reason was poor nutritional and health status of the patient. The mean of serum zinc concentration of visitor and patient control was lower than that of control group. As the degree of pulmonary fibrosis was more severe from stage Vl, V2, V3 of visitor to stage Pl, P2, P3 of patient, the mean of serum zinc concentration was lower. The ratio of serum copper/zinc of visitor and patient was higher than that of control, and that of patient was higher than that of visitor. Those results showed that the ratio of serum copper/zinc ratio more greatly expressed the degree of progression of pneumoconiosis than only copper or zinc concentration by adjustment of nutritional and health status of the patient. CONCLUSIONS: As above study results, the degree of pulmonary fibrosis of pneumoconiosis could be estimated by means of serum copper/zinc ratio.