Assessment of Job Related Factors as Determinants of Incidence of Herniated Lumbar Disc / 대한산업의학회지

OBJECTIVES: A case-control study was conducted on 2,323 male soldiers(771 herniated nucleus pulposus patients and 1542 controls) to identify risk factors for cumulative trauma disorders especially lower back. METHODS: The collecting data included individual physical, psychological, and work environmental factors. Korea Military Personality Inventory(KMPI) was used to examine the assess trait that have been associated with clinically with herniated nucleus pulposus. A measurement of the workplace support system was obtained by using of the modified work APGAR, a brief, seven-item workplace function questionnaire. RESULTS: The herniated nucleus pulposus patients were more common among Artillerymen and Engineer than among infantrymen. In logistic regression analysis of military occupational specialties, Artillerymen, Engineer, radio operator, driver were higher risk of herniated nucleus pulposus than infantrymen. Multivariate analysis of KMPI scales found hypochondriasis scale, hysteria scale, hypomania scale, social introversion scale to have strong relationship to incidence of herniated nucleus pulposus. And 'can communicate with peers' and 'enjoy job task' item of modified work APGAR to have strong relationship to incidence of herniate nucleus pulposus CONCLUSIONS: Study of the relative contributions of many physical and non physical variable shows that evaluations of back problems in workplace that exclude these highly significant work perception and psychosocial variables are of limited value. Simple, unidimensional approaches that ignore the effect of work perceptions and psychological factors on back problems reporting oversimplify a multifaceted problem. These findings emphasize the importance of adopting a broader approach to the multifaceted problem of back complaint in workplace.

Assessment of Job Related Cumulative Trauma Disorders of Dentists in Daegu Metropolitan City / 대한산업의학회지

OBJECTIVE: To investigate the symptom prevalence and aspects of symptoms for cumulative trauma disorders in dentists and elucidate their associated factors. METHODS: A questionnaire-based investigation on demographic factors, work-related characteristics, psychosocial factors and symptoms of 512 dentists practicing in Daegu metropolitan city was conducted. Subsets of psychosocial characteristics, including job demand(5 items), psychosomatic strain(5 items), job insecurity, and type A behavior were also assessed. For the evaluation of symptoms early developed questionnaire by Song(1997)was used to investigate the parameters related to pains in the neck, shoulder, arm and elbow, wrist, finger, back or discomforts, such as pricking and numbing. RESULTS: The symptom prevalence of cumulative trauma disorders, calculated based on NIOSH criteria, was high at 63.3 %; the most frequent site of complaint was the shoulder, followed by neck, back, hand and wrist, knee, foot and ankle. The most common approach position was direction of 9 to 10 o'clock. Most subjects had 5-10 years of work experience and those with such years of experience also complained most frequently of symptoms in the neck and shoulder areas. As to rate of symptom complaint according to the type of dental procedure, the highest rate was associated to periodontic treatment. According to age, those between the age of 30-40 had the highest symptom prevalence rate at 70 %. According to sex, women had the higher symptom prevalence rate. Unmarried subjects also had higher symptom prevalence rate. The results of logistic analysis showed that the higher the psychosomatic strain and job demand, the higher the symptom prevalence rate of cumulative trauma disorders. Moreover, the higher the score of type A behavior, the higher the symptom prevalence rate, and even those who changed the location of their practice for the last three months also showed high symptom prevalence rate. CONCLUSIONS: The results of multiple logistic regression analysis, which incorporated demographic, work-related and psychosocial characteristics as independent variables, showed that women were at a higher risk than men in developing cumulative trauma disorders; and that the higher the psychosomatic strain and more frequent type A behavior, the higher the risk of developing cumulative trauma disorders. The above results seem to suggest that not only continual, repeated fine and skillful musculoskeletal movements and lengthy hours in an uncomfortable position but also the psychological stress related to patient satisfaction, can lead to cumulative trauma disorders.

Assessment of Neurobehavioral Performance among Welders Exposed to Manganese / 대한산업의학회지

OBJECTIVES: A cross sectional study was carried out in the welders exposed to manganese and control group. The aim of this study was to assess the adverse effects of manganese on central nervous system of welders. METHODS: The study group consisted of 49 welders and the reference group, 49 workers matched with welders for age and educational level in automobile manufacturing company. Concentration of manganese in welding hume, in blood, and cumulative exposure index(CEI) were determined for each subject. For each group, computerized neurobehavioral test including Simple Reaction Time, Digit Symbol, Digit Span, and Finger Tapping Speed of Swedish Performance Evaluation System were applied. RESULTS: Exposure level of manganese in welders were very low(mean CEI 0.069). Welders exposed to manganese had slower response speed, slower motor steadiness, and shorter memory span than control group. But these differences were not statistically significant. The performance of Finger Tapping Speed tended to lower as environmental and biological exposure index got higher. Other neurobehavioral tests were found to have a little association with the exposure indices. CONCLUSIONS: There was no significant difference of neurobehavioral performance between welders and control group. This study indicates that Finger Tapping Speed measuring motor steadiness might be a one of useful tests for early detection of adverse effects of welding on central nervous system.

Concentration of Lead, Cadmium, and Mercury in Scalp Hair, Cerebellum, Cerebrum, Heart, Kidney, Liver, Lung and Spleen from Autopsy Subjects : Relationship between Scalp Hair and Internal Organs / 대한산업의학회지

This study was conducted to measure the lead, cadmium and mercury levels in the scalp hair, cerebellum, cerebrum, heart, kidney, liver, lung, and spleen of the 60 Korean autopsy subjects and assess the relationship among those samples. The mean lead level in the scalp hair was 12.29+/-12.51 microgram/g and no significant difference was detected in lead concentrations between the two sexes. Among the internal organ tissues the cerebrum contained the highest level of lead. This is followed by the cerebellum, spleen and liver respectively. After which the kidney and lung showed a close similarity at relatively low concentrations and the heart contained the lowest concentration. There was also no significant variation found between sexes in a comparison of lead in the internal organ tissues. The concentrations of cadmium in kidney were 127.33+/-89.36 microgram/g and considerably higher than those in the other internal organs. The liver contained the next highest level of cadmium. In both sexes, the consistent difference was noted in the cadmium concentrations of the kidney, heart and spleen. Yet female cadmium level was higher than the male's. The concentrations of mercury in the kidney and liver were 1.26+/-2.89 microgram/g, 0.59+/-0.54 microgram/g and considerably higher than those in the other internal organs. The mean mercury level in the scalp hair was 1.29+/-0.64 microgram/g and no marked difference was noted in both sexes. The lead concentration in the spleen increased with advancing age, though not statistically significance, and most of the internal organ tissues that were examined showed no evidence of increased lead concentration with age. The kidney, cerebrum, spleen and cerebellum showed increased cadmium concentrations with age. Also as well as the internal organ tissues that were examined showed no evidence of increased mercury concentration with age. The lead concentrations in the liver and lung were higher in the urban area than in the rural area, but the lead concentration in the kidney was higher in the rural area. No difference was noted in tissue cadmium and mercury concentrations as to the area of residence either. The physical workers had greater concentrations of lead in cerebellum than did housewives or the unemployed. Yet no difference was noted in the other tissues between the two groups. In the cerebellum, cerebrum, heart, and spleen, the physical workers had greater concentrations of cadmium than students or mental workers. Also physical workers had greater concentrations of cadmium in lung than housewives or the unemployed. In contrast to lead and cadmium, both the housewives and the unemployed had higher concentrations of mercury in cerebellum and cerebrum than physical workers, but there was no difference was noted in the other tissues between the two groups. In the lead concentration, there was no statistically significant correlation between the scalp hair and examined internal organ tissues. There was a close relationship between lead levels in cerebellum and cerebrum (r=0.465, p<0.01), as well as a relationship between the cerebellum and the kidney(r=0.300, p<0.05). There was no statistically significant correlation between the cadmium levels in the scalp hair and in the examined internal organ tissues. Positive correlations were found between the cadmium concentrations in the cerebellum and the cerebrum(r=0.5543, p<0.01), heart(r=0.480, p<0.01), kidney(r=0.376, p<0.01) and spleen(r=0.408, p<0.01). Also positive correlation was found between in the cerebrum and the heart(r=0.377, p<0.01), kidney(r=0.484, p<0.01), liver(r=0.265, p<0.05), lung(r=0.458, p<0.01) and spleen (r=0.483, p<0.01). There was also no statistically significant correlation between the mercury levels in the scalp hair and in the examined internal organ tissues. Positive correlation was found between the mercury concentrations in the cerebellum and cerebrum(r=0.760, p<0.01), heart(r=0.270, p<0.05), liver(r=0.425, p<0.01), lung (r=0.488, p<0.01) and spleen (r=0.534, p<0.01), and also positive correlation was found between in the cerebrum and heart(r=0.376, p<0.01), liver(r=0.350, p<0.01), lung(r=0.554, p<0.01) and spleen (r=0.489, p<0.01). Various epidemiological studies reported usefulness and reliability of using scalp hair as a monitor of a environmental pollutants. In this study, there was statistically significant correlation of lead, cadmium and mercury levels in most of the tissues that were examined, but there was no statistically significant correlation between the lead, cadmium and mercury levels in the scalp hair and most of examined internal organ tissues. The findings of this study would suggest that it is still uncertain to using scalp hair as a biological monitoring.