Performance of Neurobehavioral Tests Among Welders Exposed to Manganese / 대한산업의학회지

To study neurobehavioral effects for manganese fume exposure of welders, we administrated questionnaire about subjective symptom, related with manganese exposure. Neurobehavioral Core Test Battery of World Health Qrganization(NCTB) and finger tapping for 98 welders and 29 non-welding workers. We adopted welding duration as a criterion for exposure assessment, because of the lack of the longitudinal valid data and differences in airborne concentrations of manganese in welding types, such as shielded metal arc and CO2 arc welding. Neurologic, musculoskeletal and concentration symptoms were significantly increased by increase of welding duration. Performance of finger tapping preferred hand, Santa Ana dexterity test preferred hand and correct number of pursuit aiming were significantly decreased by increase of welding duration. These results comparable with previous studies that suggest neurobehavioral test, especially motor test, to be an appropriate tool to detect early neurobehavioral abnormalities related with manganeses exposure.

A Study on the N-methylformamide Excretion Rate of Workers at Synthetic Leather Factories in Korea / 대한산업의학회지

This study was conducted to examine the excretion rate of dimethylformamide (DMF) from the workers exposed to DMF. The study was done at two synthetic leather factories located in Kyeonggi-do from the period of May 2 to 30, 1996. N-methyl- formamide (NMF) concentrations in urine were measured and compared by the three exposure level of DMF in air. The mean concentration of the Low (dry and winder part). Moderate (rinsing part) and High (mixing and coating part) exposure group were 3.99+/-3.54. 10.19 +/-5.69 and 32.10+/-7.87 mg/m3 during workshift of 8 hours, respectively. The mean concentration of urinary N-methylforinamide (NMF) were 2.13+/-2.58, 11.16+/-4.98 and 26.24 +/-7.35 mg/g creatinine, respectively. The concentration of NMIF in urine could reach to maximum in 3 hours and was reduced nearly to zero in about 18 hours after exposure to DMF.

Factors Associated with Psychoneurobehavjral Outcomes in Workers Exposed to Manganese / 대한산업의학회지

The risk posed to human health by environmental manganese (Mn) exposure is unknown. The purpose of this study is to establish if subclinical effects related to Mn exposure and examine the factors influencing psychoneurobehaviral outcomes of Mn exposed workers. This study involved 121 male workers of welding, alloy furnace, and manufacturing of welding stick. Study investigations include: a questionnaire covering demographic characteristics, job and exposure history and medical symptoms and conditions, monitoring workplace air for personal exposure to respirable and inhalable manganese, analysis of blood and urine samples. psychoneurobehaviral test(neurobehaviral core test battery (NCTB), signal change on magnetic resonance imaging (MRJ) scans, minimental state and neurological examination). The main results of this study were as follows: 1. Preliminary results showed that, with increasing manganese exposure, neurobehaviral performance was poorer and signal change on MRI scans increased. 2. The results of examination revealed significant relations on psychoneurobehaviral out-comes (neurobehaviral performance, signal change on MRI scans, and neurological features). 3. In multiple regression, age and educational status as demographic variables and exposure level were significantly related to 4neurobehaviral test. Also exposure level and serum Mn concentrations were positively relatel to signal change on MRI scans and neurological features affected by Mn on the brain (signal change). 4. Psychoneurobehaviral outcomes from Mn exposure were related to neurobehaviral performance, signal change on MRJ scans, neurological features and profile of mood states (POMS), and influnced positively with age, alcohol and smoking history, and duration of Mn exposure, negatively with educational status. Serum Mn concentrations in combination with brain MRI scans, and perhaps a battery of neurobehaviral tests, appear to be the best way to monitor excessive exposure to Mn. These results are consistent with our knowledge on Mn action on the brain and are similar to the type of neurobehaviral dysfunction. They suggest that there may be age, educational status, and life style (alcohol and drinking history) differences with chronic environmental exposure. These findings suggest further evaluation, particularly on relationships between Mn exposure, aging, and susceptibility factors.

Neuropsychiatric Symptoms of Workers Exposed to 2-Bromopropane / 대한산업의학회지

To investigate the impact of 2-bromopropane on neuropsychiatric symptoms, 33 exposed workers and 77 non-exposes workers in electronic company were recruited. Neuropsychiatric symptoms were assessed using self-administered questionnaire. Memory disturbance, concentration disturbance, sleep disturbance, understanding disturbance and acute irritation symptom were more frequent in workers exposed to 2-bromopropane. To investigate the association between 2-bromopropane exposure and neuropsychiatric symptoms, total symptom scores of exposed workers were compared with those of non-exposed workers. Mean value in the exposed workers was significantly higher than that of non-exposed comparisons. The mean value of total symptom score of smokers in exposed workers was significantly higher than that of smokers in non-exposed workers. In multivariate regression analysis, exposure status was significant predictor for total symptom score after controlling the effects of age, sex, education, smoking status and alcohol intake. Above findings suggest that 2-bromopropane was significantly associated with neuropsychiatric symptoms. Therefore, it is recommended that further research with objective assessments and long follow-up should be done to confirm the results of this study.

Induction of Hepatic Microsomal Cytochrome P450 by Styrene in Rat / 대한산업의학회지

The effects of styrene on the induction of cytochrome P-450s (P450), (P4501A1/2, P4502B1/2 and P4502El) and activities of other related enzymes were investigated in the male Sprague Dawley rats which were treated with styrene 500 (S1), 1,000 (S2) 1,500 (S3) mg/kg in olive oil intraperitoneally once a day for two days and sacrificed for the preparation of liver microsomes after 24 hrs. 1. The contents of total protein and P450 in the microsomes derived from the styrene treated groups were slightly higher than those from the control group except those from the 53 group (1,500 mg styrene/kg body weight) . The decreases in microsomal protein contents was prominent in the S3 (p<0.05), but the P450 contents was increased significantly in the S2 (p<0.05). 2. The activities of NADPH-P450 and NADH b5 reductase in hepatic microsomes derived from the treated groups were significantly increased in the treated groups(p<0.05). 3. The activities of PROD were also prominently increased with the treatment of styrene except in 53 group, but the activity of EROD was decreased by styrene treatment. The activities of pNPH in the styrene treated groups were higher than that of the control group (p<0.05). 5. Western blotting with monoclonal antibodies against P4502B1/2 isozymes showed the presence of P4502B1/2 in hepatic microsomes from the rats treated with styrene, and the increase in the densities of immunoblots were corelated with the dosages of styrene. The blot densities against P4501A1/2 and P4502El were slightly increased in the styrene treated groups compared with the control group. These results suggested that styrene could primarily induce P4502B1/2 as major and P4501A1/2 and P4502El in minor forms for the metabolism of styrene in rats.

Induction of Hepatic Microsomal Cytochrome P450 by Styrene in Rat / 대한산업의학회지

The effects of styrene on the induction of cytochrome P-450s (P450), (P4501A1/2, P4502B1/2 and P4502El) and activities of other related enzymes were investigated in the male Sprague Dawley rats which were treated with styrene 500 (S1), 1,000 (S2) 1,500 (S3) mg/kg in olive oil intraperitoneally once a day for two days and sacrificed for the preparation of liver microsomes after 24 hrs. 1. The contents of total protein and P450 in the microsomes derived from the styrene treated groups were slightly higher than those from the control group except those from the 53 group (1,500 mg styrene/kg body weight) . The decreases in microsomal protein contents was prominent in the S3 (p<0.05), but the P450 contents was increased significantly in the S2 (p<0.05). 2. The activities of NADPH-P450 and NADH b5 reductase in hepatic microsomes derived from the treated groups were significantly increased in the treated groups(p<0.05). 3. The activities of PROD were also prominently increased with the treatment of styrene except in 53 group, but the activity of EROD was decreased by styrene treatment. The activities of pNPH in the styrene treated groups were higher than that of the control group (p<0.05). 5. Western blotting with monoclonal antibodies against P4502B1/2 isozymes showed the presence of P4502B1/2 in hepatic microsomes from the rats treated with styrene, and the increase in the densities of immunoblots were corelated with the dosages of styrene. The blot densities against P4501A1/2 and P4502El were slightly increased in the styrene treated groups compared with the control group. These results suggested that styrene could primarily induce P4502B1/2 as major and P4501A1/2 and P4502El in minor forms for the metabolism of styrene in rats.

Medical Surveillance of Glass Fiber Workers in Korea / 예방의학회지

The industrial use of MMMF(man-made mineral fibers), has been increasing, particularly since the banning of most asbestos products. Fibrous minerals can cause health abnormalities currently associated with occupational exposure to glass fiber. This study was conducted to evaluate health risks of glass fiber manufactory workers within the country. we examined questionaries, physical examination including auscultation, chest x-ray, pulmonary function test for 488 male workers, to go through their dermal itching symptoms and respiratory evaluation. we had the results as follows. 1. In 45% of the workers itching had been expressed at their entrance. At that time we was investigating, 18.5% had itching, and most of them complained it when they fall asleep and night. The frequent itching site is waist and groin, upper and lower extremity in order, and it had been expressed mainly during summer and winter. 2. As the results of ventilatory functions test, 6.0% were obstructive type, 1.0% were restrictive type. so, glass fiber exposures should be controlled or elimination by protective devices in the workplace. 3. The means of FVC, FFV1, FFV1% were in normal range. As the comparison of ventilatory functions by age groups, MMF was decreased significantly for the group, 50 years old and more than other groups. And the comparison by the serving periods at glass fiber producing factory, MMF was decreased for the workers had worked for 11-15 years. Therefore, MMF be more sensitive index in the evaluation of ventilatory impairments caused by glass fiber workers.

Bronchial Hyperresponsiveness in Workers Exposed to Isocyanates / 예방의학회지

We studied the association of nonspecific bronchial hyperresponsiveness with general characteristics, exposure concentration, respiratory symptoms, chest x-ray findings, past histories and pulmonary function. We determined bronchial hyperresponsiveness by methacholine challenge test. And we conducted a respiratory symptom questionnaire and performed spirometry on 111 workers occupationally exposed to isocyanates in various industries. About 21.6% of subjects had bronchial hyperresponsiveness. No significant differences were observed between the hyperresponsive and non-responsive group with respect to age, sex, employment period, height, and smoking histories cough and breathlessness were significantly associated with the bronchial hyperresponsiveness. The hyperresponsive group had more experience of bronchitis and asthma in the past than the non-responsive group. The lower FEV1 and FEV1 % were closely related with bronchial hyperresponsiveness. Bronchial hyperrespoosiveness seems to be associated with some of respiratory symptoms, past histories and pulmonary function parameters in workers exposed to isocyanates.

The Geographic Patterns of The Adult Male Bladder Cancer Patients in Korea: Clue as to the Occupational Exposure / 한국역학회지

We calculated the age specific Proportionate Morbidity Ratio(PMR)' for different areas as the outcome index by using the national cancer registry data(1988 1991) to assess the patterns of stomach cancer and bladder cancer. Also, we calculated 'Manufacturing workers Concentration Index(MCI)' for different areas as the exposure index by using the census data reported in 1980 to assess the relationship between cancer site specific PMRs and MCIs. As a result, we found the significant correlation(r=0.61, p=0.002) between the bladder cancer in the age of 40s and the industrial exposure indicator. Future analytic studies should be fruitful in identifying more occupational risk factors for bladder cancer. Investigation of cancer incidence including geographic variations and difference by age may identify patterns suggesting occupational exposures.

Effects of Ethanol on the Activities and Inducibility of Trichloroethylene Metabolic Enzyme System in Rat Liver / 예방의학회지

This study was performed to find out the influences of ethanol on the metabolism of trichloroethylene(TRI) in rats. TRI in corn oil at the dosage of 150, 300, 600 mg/kg was injected peritoneally once a day for two days to two groups. In one group ethanol(4 g/kg) was taken orally 30 minutes before TRI injection, and the other group ethanol was not. The results of experiments are as follows: 1. The contents of cytochrome P-450 and b5 had inverse relationship with in-jected TRI amounts in both groups. 2. The activity of NADPH P-450 reductase was decreased slowly in TRI injected group related with TRI amount, but decreased drastically in the group pretreated with ethanol. 3. The activity of NADH b5 reductase had relationship with injected TRI amount, but the statistical significance was found only in the groups of 300 and 600 mg/kg of TRI injected without relevance to ethanol when compared with the group that was not injected. 4. The activity of ADH was more decreased and ALDH activity was more increased in groups that TRI injected and ethanol was pretreated with ethanol groups than in group without any treatment. These results suggest that ethanol may inhibit epoxide formulation, the first step or TRI metabolism, and change from TCE-OH to TCA also.

A study of the response of teachers and students on the traffic noise / 예방의학회지

The purpose of this study is to reveal how the road traffic noise influences on the response of teachers and students, which composed of conversation, studying, relation, and physical disturbances. The research method used in this study was self- administrated questionnaire. Samples of the survey were composed of 420 persons(l14 teachers and 306 students) who are exposed to traffic noise less than 65 dB(A) from two junior high schools and 410 persons(140 teachers and 270 students) from two noisy junior high schools which the road traffic noise above 65 dB(A). In the response of both of the teachers and students in noisy(above 65 dB) schools complaints of disturbances of conversation, studying, relaxation, and physical disturbances are much higher than that of less noisy schools' teachers and students(p<0.01 ). On the occasion of time and season, the subjects answered the traffic noise cause high troublesome and stresses in the afternoon(12:00-17:00) and summer respectively. It is necessary to provide governmental comprehensive and fundamental measures to improve the noisy school environments.

Prevalence of Asbestosis in Korean Asbestos Industry / 대한산업의학회지

Asbestos industry has been in operation over 60 years in Korea. However, the prevalence of asbestosis has not been yet reported. With rapid turn-over of workers, previous cross-sectional studies of current workers on the job could not find cases with exposures long enough for the development of asbestosis. This study was done to evaluate asbestosis prevalence of those worksites with operation history of more than 20 years. In total, 139 workers from 5 worksites were examined. Asbestos industries covered in the study include 2 asbestos textile, 1 brake lining, and 2 ship repairing worksites. Chest x-ray was taken from all workers and read by two exports familiar with pneumoconiosis classification according to 1980 ILO guidelines. Those with findings compatible with asbestosis were further checked with high resolution computerized tomography (HRCT). Pulmonary function tests were done according to ATS guidelines, and occupational and previous medical history was taken through a standardized interview. Air-borne asbestos was measured according to NI0SH method 7400. The air-borno asbestos concentrations ranged from 0.2-1.3 f/cc for asbestos textile, from 0.7~l.0 f/cc for brake lining, and from 6.3-7.8 f/cc during asbestos removal at ship repairing worksite. Of the 139 workers 25 had abnormal chest radiographic findings, and 10 of them had findings compatible with pneumoconiosis. When work history and current asbestos measurements were accounted, 9 workers who had more than 10 years of asbestos exposure history showed chest radiographic findings of pneumoconiosis with Finally, 4 workers showed finding of pulmonary fibrosis and/or pleural thickening at HRCT, and 2 of them had restrictive lung function changes. The study results showed that, among 139 sutjects, there were 4 (3%) definite asbeatosis cases confirmed with HRCT. The prevalence of probable asbestosis was 7% for 10-14 years of exposure, 13% for 15-19 years of exposure, and 23% for 20 or more years of exposure. The prevalence of compensable asbestosis with abnormal lung function was 4-6% for those with 15 or more years of exposure.

Brain Stem Auditory Evoked Potential and R-R interval Analysis of the Workers Exposed to Trichloroethylene / 대한산업의학회지

In order to evaluate the effects of trichloroethylene (TCE) on the central and autonomic nervous system, the brain stem auditory evoked potentials (BAEPs) and the electrocardiographic R-R interval variability (CV(rr)) were measured in three groups of workers (11) working in TCE degreasing process, workers (4) exposed to lead and two groups of workers (12) not exposed to any kinds of neurotoxicants. Two components of the CVrr reflecting parasympathetic activity (C-CV(rsa)) and sympathetic and parasympathetic activities (CCV(mwsa)) were examined. The TCE workers were exposed to TCE at the level of less than 1 hour per week while the degreasing material was changed. There were no differences in the latencies of BAEPS and CV(rr) and the components of the CV(rr) between control and TCE and lead groups. However, two lead workers had the blood lead level of less than 60 g/dl recommended as present biological guideline by the Ministry of Labor, showed the delayed latencies of V5 and I-V in BAEP. This results suggested that intermittent TCE erposure didn't affect the auditory nervous pathway and the autonomic nervous system, however, lead exposure might affect the central nervous system at the level of less than 60 g/dl in blood lead.

Studies on Activities of Xenobiotic Metabolic Enzymes in Rats treated with Trichloroethylene / 대한산업의학회지

Trichloroethylene (TRI) is one of the most widely used organic solvent in many industries. It is used a degreasing agent, extract and dillution solvents. TRI is metabolized by liver microsomal cytochrome P4SO to reactive intermediates, which are considered responsible for its hepatotoxicity. Cytochrome P450 is a key enzyme in the first step of TRI metabolism resulting in chloral hydrate (CH) formation, which is a rate-limiting step in TRI metabolism. This study was perfomed to find out the change of hepatic cytochrome P450 levels and of electron transport system for P-450 dependent reaction. Intraperitoneal injections of TRI were done to the male Sprague Dawley rats(mean body wights,170+/-10g) in corn oil at the dosage of 150,300,600 mg/kg for 2 days. The results of experiments are following : 1. The contents of microsomal protein, cytochrome P450 and b(5) are tended to be decreased with increasing amount of TRI, but not significantly (p>0.05) . 2. The activity of NADPH-cytochrome P450 reductase is slowly decreased by increasing amount of TRI, but not slgnificantly (p>0.05) . On the other hand, the activity of NADH-b(5) reductase is increased with increasing amount of TRI (p0.05) . This result suggests that the inductive pattern of TRI may not be related to P 450IAl and P450IIB.

Respiratory Symptoms and Ventilatory Function Impairment of Taxi Drivers / 대한산업의학회지

The prevalence of respiratory symptoms and impairments of ventilatory capacity were studied in a group of 74 taxi drivers in Inchon area. As a reference group, 94 office workers of same area, matched with cigarette smoking, were also included in this study. Taxi drivers complained of respiratory symptoms much more than reference group. Those were cough, sputum production, chest tightness and shortness of breath. The ventilatory capacities, FVC (forced vital capacity), FEV(1.0) (forced expiratory volume 1 second), MMF (maximal mid flow) and PFR (peak flow rate), were measured. All measured values of ventilatory capacities of taxi driver were significantly decreased than those of reference group. The rate (56.8%) of ventilatory capacity impairment in taxi drivers was significantly larger than those (14.9%) of reference group, and the most of them were restrictive type impairments. Also, Job variable, prefessional driver or not, was selected as important determinant for ventilatory capacity impairment.

The study of blood carbon disulfide in rats after oral administration of carbon disulfide / 대한산업의학회지

No abstract available.

Perception and attitude toward group health management and service system for small and medium industries in Inchon / 예방의학회지

To investigate perception and attitude toward Group Health Management and Services System for Small and Medium Industries, a survey using self-administered questionnaire was conducted to a part of industries in Inchon, at October 1992. Major dependent variables were perception, attitude, and practice related with Group Health Management and Service System; these variables were measured by 3-point Likert like scale consisted of 7, 5, and 5 items, respectively. Data were collected in 149 industries, 72.7% out of 205. Perception was slightly high, 1.25; attitude was some positive, 1.46; and practice was some passive, 0.94. Major determinants of perception, attitude, and practice were sex and age of industry's health manager; perception influenced upon attitude, and perception and attitude had positive effect upon practice. To activate Group Health Management and Service System, it is necessary to develop education and promotion programs for industry's health managers of small and medium industries.

Workers' health status related working environments in small and medium sized industries / 대한산업의학회지

No abstract available.

Effects ethanol and phenobarbital on metabolism of trichloroethylene in rats / 대한산업의학회지

No abstract available.

The development of industrial health information management system / 대한산업의학회지

No abstract available.