The Effects of Indoor Air Quality on the Neurobehavioral Performance of Elementary School Children / 대한산업의학회지

OBJECTIVES: Most studies on the indoor air quality of newly built schools have focused only on the number of schools exceeding a standard or on subjective symptoms, such as sneezing, irritated eyes and an irritated nose. However, there has been no report on how poor indoor air quality affects children's academic performance. This study evaluated the effects of indoor air quality on the neurobehavioral performance of elementary school children. METHODS: This study measured the indoor air pollutants and compared children's performance, using a computerized neurobehavioral test, between a newly built and a 12-year-old school. In addition, a questionnaire was administered regarding the indoor air quality related symptoms of children in a newly built and a 12-year-old school. RESULTS: In the newly built school, the formaldehyde levels in the 1st and 4th classes with an open window were 34.6 and 27.3 microgram/m3, respectively. The levels in the 1st and 4th classes with the window closed were 80.2 and 127.1 microgram/m3, respectively. In the 12-year-old school, the formaldehyde levels in 1st and 4th class with open and closed window were 12.6 and 7.5 microgram/m3, and 19.8 and 25.2 microgram/m3, respectively. With respect to total volatile organic compounds, the levels in the 1st and 4th classes with the window open in the newly built school were 87.2 and 428.2 microgram/m3, respectively. In the 1st and 4th classes with the window closed, the total volatile organic compounds were 1,283.5 and 1,715.4 microgram/m3, respectively. In the 12-year-old school, the total volatile organic compounds were 240.9 and 150.8 microgram/m3, and 371.9 and 448.0 microgram/m3 in the 1st and 4th classes, respectively. In the case of a newly built school, the performance of the students in the neurobehavioral test in the 4th class with the window closed was 8.3% lower than for those in the 1st class with the window closed, but was only 5.9% lower when the windows were open. There was a statistical significant difference in the total numbers of symptoms between the two schools. CONCLUSIONS: These results suggest a proper evaluation of the indoor air quality within schools is required into both the level of contamination and the health effects of these contaminants toward children.

Blood Pb, Urine Cd and Health Assessment of Residents in the Vicinity of Abandoned Mines in Gyeongsangbuk-do / 대한산업의학회지

OBJECTIVES: The objective of this health assessment is to evaluate the health risks that may result from exposure to abandoned mine tailings in Gyeongsangbuk-do. The tailings are remnants from an earlier flotation mill and mining operation that was in business from the early 1930's until 1970. METHODS: The soil, stream water, and drinking water in and around three abandoned mine areas, Soochul, Gumjang, Darock, and three control areas located in Gyeongsangbuk-do were analyzed for level of Cd, Pb, Cu, As, and Hg. Potential chronic health effects were evaluated by interview and medical examination. RESULTS: Some soil and stream samples exceeded the Korean standard for soil contamination in farmland and the Korean standard of water contamination in streams respectively. Blood lead (5.37 microgram/dl) and urine cadmium (2.79 microgram/g Cr) levels of the residents in the vicinity of the abandoned mine sites were significantly higher than of the residents in the control areas (blood lead, 4.34 microgram/dl; urine cadmium, 1.62 microgram/g Cr). There were no significant differences between the mining and control areas in terms of blood pressure, Hb, BUN, creatinine, SGOT, SGPT, fasting blood sugar, and the prevalence of potential chronic diseases. CONCLUSIONS: The results of the assessment suggested that the three abandoned mine sites do not pose an apparent health risk to nearby residents. Nevertheless, the elevated blood lead and urine cadmium levels in the residents of the abandoned mine site suggested that it might be an important source of heavy metals contamination. Therefore, a nationwide evaluation program is needed to assess the potential health risks of residents living in the vicinity of abandoned mine sites.

Effects of Familiarity with Computer and Type of Keyboard on Computerized Neurobehavioral Performance Tests / 대한산업의학회지

OBJECTIVES: A stratified cross-over study was conducted to evaluate the effects of familiarity with computer on the performance of computerized neurobehavioral tests. Effects of keyboard type on the relationship between familiarity with computer and performance of computerized neurobehavioral tests were also examined. METHODS: We tested 70 persons classified into three groups according to degree of familiarity with computer: Group 1 was people with no computer competency, Group 2 had slight working experience on the computer, and Group 3 were highly competent and efficient on the computer. For each group, we executed 4 tests of the Korean version of the Swedish Performance Evaluation System (Simple Reaction Time, Addition, Symbol Digit, and Finger Tapping Speed). Three types of keyboard were applied for all three groups. Type 1 keyboard was a conventional layout with 106 keys. We removed the unused keys except for the 17 which were used in the test and remodeled the normal keyboard into Type 2 keyboard with 17 keys (10 numeric keys, 4 arrow keys, space bar, and both Ctrl keys). Type 3 keyboard with 11 keys consisted of 10 numeric keys and the space bar was newly developed for the computerized neurobehavioral performance test. RESULTS: It was found that Simple Reaction Time, Addition, and Finger Tapping Speed were not affected by familiarity with computer and type of keyboard. The mean reaction time of Symbol Digit adjusted by age and educational level with Type 1 keyboard was found to have significant difference among the three groups (F=3.347, p=0.041). The performance of Symbol Digit in Group 1 was found to be significantly lower than that in Group 2. The performances of Symbol Digit measured with Types 2 and 3 keyboards were not found to have significant differences among the three groups. In Groups 1 and 3, the performances of Symbol Digit measured with Type 1 keyboard were found to be significantly lower than those of other keyboards. CONCLUSIONS: According to the above results, Simple Reaction Time, Addition, and Finger Tapping Speed have high priority over other neurobehavioral tests for the workers having varying degrees of computer familiarity. It is also suggested that familiarity with computer and keyboard type needs to be considered in interpretation of the performance of Symbol Digit. We recommended executing the computerized neurobehavioral test with keyboards 2 or 3 to reduce the effect of computer familiarity.

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.

Musculoskeletal Disorders and Related Factors of Symphony Orchestra Players / 대한산업의학회지

OBJECTIVES: Several studies have shown that performance related musculoskeletal disorders present a significant and common health problem for instrument players. This study was conducted to investigate the symptom prevalence rate of performance-related musculoskeletal disorders and risk factors on symphony orchestra players. METHODS: The symptom prevalence rate of musculoskeletal disorders and related factors including demographic factors, occupational factors, psychosocial factors, practice and performance-related behaviors of on 156 symphony orchestra players in Taegu city were surveyed with a self-administered questionnaire. RESULTS: Instrument players have performed for 14. 6 years in average and worked 4. 9 for years in average as a member of symphony orchestra. The subjects consisted of 106 string players, 48 wind players, and 8 percussion players. The symptom prevalence rate of musculoskeletal disorders according to the NIOSH surveillance criteria was 79. 6 % and operational criteria by authors was 45. 9 %. The prevalence rate of viola players was higher than violin players, and the prevalence rate of the bass players was higher than that of the cello players. In univariate analysis, job insecurity, irregular performance, stress from family problems, and performance related psychosomatic strains had a significant association with the prevalence rate of musculoskeletal disorders. In multiple logistic regression, job insecurity, irregular performance, and stress from family problems were significant variables affecting the prevalence rate of musculoskeletal disorders of instrument players. CONCLUSIONS: This study suggest that symphony orchestra players are high risk group of musculoskeletal disorders. Irregular performance schedule and psychosocial stress including job insecurity, and psychosomatic strain were important risk factors of players musculoskeletal disorders. An exercise program such as stretching before and after performance, regular performance schedule and reduction of psychosocial stress might be helpful for prevention of musculoskeletal disorders of instrument players.

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.

Evaluation of Reliability of Traditional and Computerized Neurobehavioral Tests / 대한산업의학회지

OBJECTIVES: Thls study was conducted to select more reliable neurobehavioral tests that are compatible with the characteristlcs of Korean workers and their health management system. METHODS: To compare the reliability of neurobehavioral tests, test and retest of five computerized and five traditional neurobehavioral tests administered to 85 medical school students and 35 hospital workers. The computerized tests include Simple reaction time, Addition, Symbol digit, Digit span, and Finger tapping speed, while the traditional tests include the trenton visual retention test, Digit symbol, Digit span, Pursuit aiming, and Pegboard. RESULTS: Computerized Addition was found to have the highest test-retest reliability (0.90) of and followed by Finger tapping speed (nondominant hand, 0.89, dominant hand, 0.85), Symbol digit(0.82), and Digit span(0.74). Only two traditional tests, Digit symbol(0.86), and Pursuit aiming(0.72), showed test-retest reliability coefficient greater than 0.70. CONCLUSIONS: These results suggest that the computerized Additions, Symbol digit, Fingel tapping speed, and traditional Digit symbol are more satisfactory for our purposes. These results may allow a reasonable selection of the most appropriate tests for periodical evaluation of central nervous system of workers exposed to neurotoxic substances in Korea.

Health of Apartment Guards and Associated Factors / 영남의대학술지

OBJECTIVES: The purpose of this investigation was to study the health status of apartment guards and associated factors. MATERIALS AND METHODS: This investigation was conducted for 1 month starting from August, 1997. Study population in this cross-sectional survey consisted of 182 guards of apartments located throughout the district of Taegu. Each subject completed a questionnaire about his general characteristics, health behaviors, job descriptions, subjective GIT symptoms and somatization and depression using Symptom Checklist-90-Reversion (SCL-90-R) by self administrated questionnaire and personal interview). RESULTS: Study subjects had one or more GIT symptoms(53.3%), somatization symptoms(83.5%) and depression symptoms(79.7%). The mean scores of GIT, somatization and depression symptoms were not different among the age groups and based on marital status, respectively, but, significantly different by education level(p<0.05). The mean scores of GIT, somatization and depression symptoms were not different among the age groups and hased on marital status, respectively, but, significantly different by regular diet and by the subject's health status(p<0.05). The mean scores of GIT, somatization and depression symptoms were not different by duration of shift work, by job tenure and by the number of managed houses but, those of somatization and depression symptoms were significantly different by level of job satisfaction(p<0.05). CONCLUSION: The health statuses of guards at apartments were different from other shift workers because of health worker effects and characteristics of their jobs.

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.

Development of Korean Neurobehavioral Test Battery - Assessment of the Validity of Traditional and Computerized Neurobehavioral Tests / 예방의학회지

Aim. A neurobehavioral test for workers exposed to organic solvents in the workplace can be affected by many factors : age, education, motivation, ethnicity, etc. To apply more suitable neurobehavioral test for Korean workers, we evaluated the validity of several items of computerized and traditional neurobehavioral tests. Methods. We have applied eleven tests : four items of computerized neurobehavioral test(Swedish Performance Evaluation System) including Addition, Symbol-Digit, Digit Span, and Finger tapping speed, and seven items of traditional neurobehavioral test consisting of Addition, Digit-Symbol , Digit Span, Benton visual retention test, Pursuit aiming, Pegboard, and Tapping. These tests were performed on 96 workers exposed to solvents, and 100 reference workers. The concurrent and construct validities were evaluated by group difference, correlation with age, educational level, hippuric acid level, neurotoxic symptom, current exposure level, multitrait-multimethod matrix, factor analysis, and discriminant analysis. Results. Statistically significant differences were observed between the workers exposed to solvents and referents in computerized Symbol-Digit, Finger tapping speed, traditional Digit-Symbol and Pegboard. The computerized Symbol-Digit, traditional Digit-Symbol, Addition, Benton visual retention test, and Pegboard were found to be related to the age. The performance of computerized Symbol-Digit, Addition, and traditional Digit-Symbol were found to be related to the educational level significantly. The computerized Symbol-Digit, Finger tapping speed, and traditional Digit-Symbol were found to be related to hippuric acid, and neurotoxic symptom. The discriminability of Finger tapping speed, and Pegboard was better than the other tests. In discriminant analysis, the model with two variables, the computerized Symbol-Digit and Pegboard, classified almost 70 percent of the workers correctly. Conclusions. These results suggest that the computerized Symbol-Digit, Finger tapping speed, and Pegboard are more satisfactory for our purpose, and the Addition, Tapping, Benton visual retention test, and Pursuit aiming are less valid than other items. These may allow the reasonable selection of core neurobehavioral tests for workers exposed to solvents in Korea.

Blood Lead and ZPP Concentrations of Underground Parking Lot Workers / 영남의대학술지

A study was conducted to investigate the blood lead and zinc protoporphyrin(ZPP) concentrations of the underground parking lot workers who exposed to vehicular exhaust aerosols which contained lead. The blood samples were collected from 25 study subjects of underground parking lot and from 33 controls in Taegu, from July to October, 1997. And also the related factors to the blood lead and ZPP concentrations were investigated. Blood lead concentration and ZPP concentration were measured by flameless furnace atomic absorption spectrophotometer (IL.551) and hemetofluorometer, respectively. The mean blood lead concentrations of study subjects and controls were 23.10+/-20.77microgram/dl and 12.99+/-12.71microgram/dl, respectively(p<0.05), and the mean blood ZPP concentrations of study subjects and controls were 40.72+/-9.46microgram/dl and 38.21+/-10.97microgram/dl, respectively. No significant correlations were observed between the blood lead concentration of the study subjects and their job duration and between blood ZPP concentration of the study subjects and their job duration. There were no statistically significant differences in the blood lead concentration and the blood ZPP concentration of smokers and nonsmokers. In multiple regression analysis on blood lead concentration of the study subjects and controls, occupation was a only significant dependent variable. In case of bood ZPP concentration, age was a only significant dependent variable in the study subjects and controls.

Sick building syndrome in 130 underground workers / 영남의대학술지

A cross-sectional study was conducted to evaluate the relationship between sick building syndrome(SBS) and the environmental factors affecting SBS on 130 underground workers and 60 controls. The study consisted of 1) a review of environmental condition 2) measurement of temperature, O2, CO2, CO, and formaldehyde and 3) a questionnaire survey of symptom prevalence and perception of environmental conditions using Indoor Air Quality questionnaire by National Institute for Occupational Safety and Health Bronchitis and dust allergy were more prevalent in underground workers significantly(p<0.05). Among the 18 symptoms related to the indoor air pollution, the experience rate of dry, itching or irritated eyes, sore or dry throat, chest tightness, tired or strained eyes and dry or itchy skin symptom is significantly different between the underground workers and controls. The diagnostic criteria of SBS was defined as at least one symptom is experienced 1-3 times a week during the last 1 month among 18 indoor air pollution related symptoms which can be relieved by moving out of the underground. Applying the criteria, the mean symptom score was significant higher in underground workers than controls significantly(p<0.05). These results indicated that underground workers are under inappropriate ergonomic and physical condition and inadequate ventilation. Their experience rate of symptoms related to indoor air pollution and prevalence of SBS was significantly higher than controls. To reduce the prevalence of SBS in underground workers, the surveillance system of indoor air quality, restriction of using fuel in underground and legislative regulations for the environment are needed to establish a better indoor air quality. Early detection, treatment and prevention of SBS through medical attention is also needed.

A cohort study on blood zinc protoporphyrin concentration of workers in storage battery factory / 예방의학회지

To investigate the effectiveness of the interventions in working environment and personal hygiene for the occupational exposure to the lead, the blood zinc protoporphyrin(ZPP) concentrations of 131 workers ( 100 exposed subjects and 31 controls ) of a newly established battery factory were analyzed. They were measured in every 3 months up to 18 months. Air lead concentration (Pb-A) of the workplaces was also checked for 3 times in 6 months interval from August 1987. Environmental intervention included the local exhaust ventilation and vacuum cleaning of the floor. Intervention of the personal hygiene included the daily change of clothes, compulsory shower after work and hand washing before meal, prohibition of cigarette smoking and food consumption at the work site and wearing mask. Mean blood ZPP concentration of the controls was 16.45+/-4.83 microgram/dashliter at the preemployment examination and slightly increased to 17.77+/-5.59 microgram/dashliter after 6 months. Mean blood ZPP concentration of the exposed subjects who were employed before the factory was in operation (Group A) was 17.36+/-5.20 microgram/dashliter on employment and it was increased to 23.00+/-13.06 microgram/dashliter after 3 months. The blood ZPP concentration was increased to 27.25+/-6.40 microgram/dashliter on 6 months (p<0.01) after the employment which was 1 month after the initiation of intervention program. It did not increase thereafter and ranged between 25.48 microgram/dashliter and 26.61 microgram/dashliter in the subsequent 4 results. Mean blood ZPP concentration of the exposed subjects who were employed after the factory had been in operation but before the intervention program was initiated (Group B) was 14.34+/-6.10 microgram/dashliter on employment and it was increased to 28.97+/-7.14 microgram/dashliter (p<0.01) in 3 months later(1 month after the intervention). The values of subsequent 4 tests were maintained between 26.96 microgram/dashliter and 27.96 microgram/dashliter. Mean blood ZPP concentration of the exposed subjects who were employed after intervention program had been started (Group C) was 21.34+/-5.25 microgram/dashliter on employment and it was gradually increased to 23.37+/-3.86 microgram/dashliter (p<0.01) after 3 months, 23.93+/-3.64 microgram/dashliter after 6 months, 25.50+/-3.01 microgram/dashliter (p<0.01) after 9 months, and 25.50+/-3.10 microgram/dashliter after 12 months. Workplaces were classified into 4 parts according to Pb-A. The Pb-A of part I, the highest areas, were 0.365 microgram/m4, and after the intervention the levels were decreased to 0.216 microgram/m4 and 0.208 microgram/m4 in follow-up test. The Pb-A of part II which was resulted in lower value than part I was decreased from 0.232 microgram/m4 to 0.148 microgram/m4, and 0.120 microgram/m4 after the intervention. The Pb-A of part III was tested after the intervention and resulted in 0.124 microgram/m4 in January 1988 and 0.081 microgram/m4 in August 1988. The Pb-A of part IV was also tested after the intervention and resulted in 0.110 microgram/m4 in August 1988. There was no consistent relationship between Pb-A and blood ZPP concentration. The blood ZPP concentration of the group A and B workers in the part of the highest Pb-A were lower than those of the workers in the parts of lower Pb-A. The blood ZPP concentration of the workers in the part of the lowest Pb-A increased more rapidly. The blood ZPP concentration of the group C workers was the highest in part III. These findings suggest that the intervention in personal hygiene is more effective than environmental intervention, and it should be carried out from the first day of employment and to both the exposed subjects, blue color workers and the controls, white color workers.

The Effects of Job Stress on Psychosomatic Strain and Gastrointestinal symptom / 대한산업의학회지

No abstract available.

Neurobehavioral Performance Test of Workers Exposed to Mixed Organic Solvents / 영남의대학술지

A cross-sectional study was performed to evaluate the effects of chronic exposure to low-dose solvent on neurobehavioral performance of 48 male workers exposed to organic solvents. A control group of 50 workers was selected from same factories. Each worker completed a medical and occupational questionnaire and four tests of Neurobehavioral Core Test Battery. These included Benton visual retention test, digit symbol, digit span, and pursuit aiming. Comparison of mean performance showed a significantly poorer performance on digit symbol, digit span, and pursuit aiming. In univariate analysis, age contributed to poor performance on Benton visual retention test and educational level was found to reduce the performance on symbol digit in both groups. Amount of alcohol intake was found to reduce the performance on digit symbol and smoking appeared to slow pursuit aiming in the exposure group. In multiple regression analysis, controlling for age, educational level, alcohol, and smoking, solvent exposure was found to be associated with performance of digit span, and number of correct dot of pursuit aiming. Age on Benton visual retention, educational level on digit symbol, and smoking on pursuit aiming were found to be a significant factors on each test items. This study suggest that short-term memory, and perception can be affected easily by chronic exposure of organic solvents which air concentration level were under the Threshold Limit Value.

ALDH2 Genetic Polymorphism and Urinary Hippuric Acid Concentration in Toluene Exposed Workers / 대한산업의학회지

In this study we evaluated the effects of the genetic polymorphism of aldehyde dehydrogenase2 (ALDH2) on toluene metabolism and determined biological exposure indices (BEIs) for toluene by the genotypes of ALDH2. The study subject were 77 men workers who are handling toluene in a video tape manufacturing factory and a textile company. Through the face-to-face interview, the information about smoking and drinking behavior wag obtained. For determination of ALDH2 poly morphism, 5 ml of venous blood sample was obtained from each subject after informed consent. DNA was extracted from the buffy coat and ALDH2 genotyping were performed using a polymerase chain reaction (PCR) method. The genotype of ALDH2 was classified into the homozygous genotype of normal ALDH2 (NN), and the heterozygous genotype of normal and inactive ALDH2 (ND), and homozygous genotype of an inactive ALDH2(DD). The concentration of hippuric acid (HA), the main metabolite of toluene, was determined in urine specimens collected at the end of shift, corrected with creatinine (HA/C), and compared with BEI for toluene, which is 2.5 g/g creatinine. The personal exposure level of toluene were monitored, using personal air sampler and analyzed by gas chromatography. The frequencies of the three genotypes in this study subjects were, NN : 45 (58.4%), ND : 26 (33.8%) and DD : 6 (7.8%), and frequencies of the genotypes in the middle or heavy toluene exposure workers were not significantly different from those in the mild toluene exposure workers. The frequencies of the DD type of ALDH2 was lower among alcohol drinkers than among non-drinkers. The urinary HA concentration of DD group was significantly lower than that of the NN or ND group, which suggests that the HA formation from toluene decreased in DD group. Regression lines were used to estimate the BEIs of the NN, ND, and DD groups. NN : y = 0.0085x + 0.23, r = 0.90 ND : y = 0.0074x + 0.21, r = 0.85 DD : y = 0.0041x + 0.82, r = 0.83 The three regression lines revealed that the estimated urinary HA concentration of NN, ND, and DD groups at 377 mg/m3 toluene(TLV-TWA) exposure were 3.43, 3.00, and 2.37 g/g creatinine, respectively. The HA concentration of the NN, and ND group were higher than that of the ACGIH BEI (2.5 g/g creatinine) ; however, the HA level of DD group was lower than the BEI. These results suggests that the ACGIH BEI is not adequate to estimate the toluene exposure of the NN, ND and DD groups at the same time. Based upon those results, a new BEI for ALDH2 deficient workers may be necessary.

Interrelation of Neuropsychiatric Symptom and Neurobehavioral Test among Workers Exposed to Organic Solvents / 대한산업의학회지

A cross-sectional study of 118 car painters and controls of 113 workers was performed to investigate the interrelation between self-reported neuropsychiatric symptom and neurobehavioral performance using Scandinavian Questionnaire 16, Zung anxiety, depression scale and Swedish performance evaluation system (simple reaction time, symbol digit, digit span, finger tapping speed). The typical symptoms characteristic of painter's syndrome were not found and no significant association was found between solvent exposure and !total score of neuropsychiatric symptom but neurobehavioral performance of simple reaction time, symbol digit and digit span had association with solvent exposure. No significant associations were found between total score of neurotoxic symptom, anxiety scale, depression scale and the neurobehavioral performance. In factor analysis, the factor of questionnaire 16 measuring function of memory demonstrated no significant association with the factor of neurobehavioral test items measuring short term memory.

Association of Lifestyle with Blood Pressure / 예방의학회지

This study was conducted to evaluate the association of various lifestyle with blood pressure. The data were obtained from the individuals who got routine health examination in Department of Occupational Medicine, Yeungnam University Hospital from June to September, 1996. Among these people, we selected 130 cases of hypertensives(97 males, 33 females) and 150 normotensives(70 males, 80 females) and study was conducted. The authors collected the information of the risk factors related to hypertension such as age, family history of hypertension, fasting blood sugar, serum total cholesterol, alcohol consumption(g/week), smoking history, relative amount of salt intake(low, moderate, high), the frequency of weekly meat consumption, BMI, daily coffee consumption(cups/day) and the frequency of regular exercise(frequency/week) through questionnaire and laboratory test. By simple analysis, BMI was significantly associated with hypertension in male(p<0.05), and the frequency of weekly meat consumption was significantly associated with hypertension in female(p<0.05). Using logistic regression model, elevated odds ratio was noted for fasting blood sugar, serum total cholesterol, family history of hypertension, alcohol consumption, salt intake and BMI, and reduced odds ratio was noted for coffee consumption and exercise in male but fasting blood sugar(odds ratio=1.022, 95% CI=1.000-1.044), family history in both of parents(odds ratio=3.301, 95% CI=1.864-4.738), salt intake(odds ratio=1.690, 95% CI=1.082-2.298) and BMI(odds ratio=1.204, 95% CI=1.065-1.343) were statistically significant(p<0.05). In female, elevated odds ratio was noted in serum total cholesterol, family history of hypertension, BMI and meat consumption. Of all these variables, the family history of hypertension in either of parents(odds ratio=4.981, 95% CI=3.650-6.312), family history in both of parents(odds ratio=16.864, 95% CI=14.577-19.151), BMI(odds ratio=1.167, 95% CI=1.016-1.318) and meat consumption(odds ratio=2.048, 95% CI=1.133-2.963) showed statistically significant association with hypertension in female(p<0.05).

Lead Concentrations of Pigeon's Tissue as Indicator of Lead pollution in Air and Soil / 예방의학회지

It has been studied that a variety of fauna and flora are sensitive biological indicators which reflect the severity of regional pollution of heavy metals, but in the center of part of Taegu city the controversial issue of lead poisoning attributable to the atmosphere which contains an increased concentrations of lead has been raised recently, it is usually hard to find suitable plants or animal in the areas with heavy traffic. Pigeons are ubiquitous in and around Taegu city area, inhabiting even the most densely populated areas with heavy traffic with its small body size, high metabolic turnover, and rather limited mobility, a pigeon, as a biological indicator is expected. This study was conducted to monitor lead pollution in the Taegu and kyongju city in Korea. We measured the lead content of the various tissue of three groups of feral pigeon(Columbia livia) and soil and atmospheric lead concentration. First group was obtained io heavy traffic area in Taegu City, the second group was obtained a park in Taegu city and the third group was obtained light traffic area in kyongju city. The air and soil lead concentration of heavy traffic area in Taegu city was 0.11 microgram/m2, 4.96 microgram/g, that of park in Taegu city was 0.05 microgram/m3, 2.65 microgram/g and that of light traffic area in kyonngju city was 0.03 microgram/m3, 0.01 microgram/g. The lead content of lung, blood, kidney, femur and liver of feral pigeons in heavy traffic area in Taegu city was significantly higher than pigeons obtained in a park in Taegu city and low traffic density area in Kyonfju city(p<0.01). But stomach lead content of three group did not reflect a significant difference. In this study positive correlation was found between atmospheric lead concentrations and the concentration of lead in the pigeon's lung(r=0.5040, p<0.001), blood(r=0.3322, p<0.01), kidney(r=0.4824, p<0.001), femur(r=0.7214, p<0.001) and liverer (r=0.4836, p<0.01). we can also found positive correlation between soil lead concentrations and the concentration of lead in the pigeon's femur(r=0.4850, p<0.001), kidney(r=0.4850, p<0.001) and liver(r=0.4386, p<0.01). In the pigeon`s tissue there were significant correlations between concentration of lead in the blood and kidney(r=0.4818, p<0.001), femur(r= 0.6157, p<0.001) and liver(r=0.3889, p<0.001). In conclusion, at the heavy traffic area in Taegu city, lead concentrations found in the atmosphere and soil are reflected in the lead concentrations of different tissue of urban pigeons. It is suggested that the tissue of pigeons can be good biological indicators of environmental lead pollution.