Job Stress, Heart Rate Variability and Metabolic Syndrome / 대한산업의학회지

OBJECTIVE: A growing body of literature has documented that job stress is associated with the development of cardiovascular disease. Nevertheless, the pathophysiological mechanism of this association remains unclear. Therefore, we tried to elucidate the relationship between job stress, heart rate variability and metabolic syndrome. METHOD: The study design was cross-sectional, and 169 industrial workers were recruited. A structured-questionnaire was used to assess the general characteristics and job characteristics (work demand, decision latitude). Heart rate variability (HRV) was recorded using SA-2000 (medi-core). HRV was assessed by time-domain and by frequency-domain analyses. Time domain analysis was performed for SDNN (Standard Deviation of NN interval), and spectral analysis for low-frequency (LF), high-frequency (HF) and total frequency power. Metabolic syndrome was defined on the basis of clustering of risk factors, when three or more of the following cardiovascular risk factors were included in the fifth quintile: glucose, systolic blood pressure, HDL-cholesterol (bottom quintile), triglyceride and waist-hip ratio. RESULTS: The results showed that job characteristics were not associated with cardiovascular risk factors. The high strain group had a less favorable cardiovascular risk profile with higher levels of blood pressure, glucose, homocysteine, and clotting factor than the lower strain group (low strain+passive+active group), but the difference was not statistically significant. The SDNN of HRV was significantly lower in the high strain group than in the low strain group. The prevalence of metabolic syndrome in the low strain, passive, active and high strain groups was 9.7%, 13.9%, 14.9% and 23.8%, respectively. In the high strain group, the metabolic syndrome was significantly related to a decreased SDNN. However, we could not find a significant association in LF/HF ratio. CONCLUSION: This result suggests that decreased HRV does not play a role in the development of disease; however, it can induce cardiovascular abnormalities or dysfunctions related to the onset of heart disease among high risk groups.

Relationship between Job Stress and Pulse Wave Velocity as a Cardiovascular Risk Factor / 대한산업의학회지

OBJECTIVE: The objective of this study was to elucidate the relationship between job stress and pulse wave velocity (PWV) as a cardiovascular risk factor. METHOD: The study design was cross-sectional, and a total of 234 industrial workers were recruited. A structured-questionnaire was used to assess the general characteristics and job characteristics (work demand, decision latitude) using a modified Karasek model. Cuffs were applied to the extremities and a microphone for phonocardiography was placed at the second intercostal space at the margin of the sternum. The subjects rested in a supine position for 5 min, and PWV was measured using a VP-1000(Colin Waveform analyzer). RESULTS: There were significant correlations between blood pressure, glucose, total cholesterol, coagulation factor and PWV. The group with low decision latitude and high decision latitude showed higher levels of PWV, but the differences were not significan. The PWV (left) was significantly higher in the high strain group than in the lower strain group. After adjustment for age and cardiovascular risk factors, job strain was still associated with PWV. CONCLUSION: These result suggest that the high strain group among workers is related to an increased risk of PWV as a marker of atherosclerosis.

The Effect of Working Noise Exposure and Military Background on the Hearing Threshold / 예방의학회지

OBJECTIVES: Impaired hearing is a prevalent occupational hazard, not only in industry, but also in the armed forces. In military life, noise has unusual characteristics, and constitutes a serious hazard to hearing. The aim of this study was to analyze the hearing threshold data in order to compare the hearing loss among shipyard workers, representing different workers, and a military service background. METHODS: A cross-sectional audiological survey, combined with a questionnaire study, was conducted on a stratified random sample of 440 shipyard workers, with long-term exposure to noise. The employees were divided into four groups, according to their working and military service backgrounds, in relation to their exposure to noise. RESULTS: As expected, the working and military noise exposure group (Group I) had significantly poorer hearing than the other groups. The high frequencies (2-8 kHz) showed the greatest difference in terms of poorer hearing in both ears. The prevalence of noise-induced hearing loss (NIHL) was highest in Group I. A logistic regression analysis was applied to determine the dependence of the NIHL in relation to age, smoking, drinking, working duration, ear protection, past history of ear diseases, and working and military service backgrounds, on the noise exposure. The important factors found to be related to the NIHL, in relation to noise exposure were: age, work duration, and working and military service backgrounds. The adjusted odds ratio estimates for NIHL in the right ear were 4.5 times greater (95% CI 1.7-11.6) for the military noise exposed group, and 7.9 times greater (95% CI 2.0-31.3) for the working noise exposed group than in the controls. The hearing thresholds at the pure-tone average and 4 kHz were significantly increased with age and work duration with both the working and military service backgrounds. CONCLUSIONS: From these results, specific preventive programs were planned, which should be assessed by epidemiological surveillance of the military noise exposed population.

Characteristics and Affecting Factors of Tinnitus in Noise Exposed Workers / 대한산업의학회지

OBJECTIVES: Tinnitus is a relatively common complaint of workers who are exposed to noise. The aim of the study was to investigate the prevalence and characteristics of tinnitus as well as the factors related to the prevalence of tinnitus. METHODS: A cross-sectional audiologic survey was combined with a questionnaire on tinnitus in a stratified random sample of 246 shipyard workers who had long-term exposure to noise. RESULTS: Forty seven had tinnitus, giving a prevalence of 19.1 percent. The tinnitus was the here and now in 44.7 percent of cases, bilateral in 51.1 percent, and caused sleep disturbances in 12.8 percent. The prevalence of tinnitus was highest in shipfitters and those with longer exposure duration.The workers with tunnitus had consistently higher hearing thresholds at both high and low frequencies than those with no tinnitus.The workers with tinnitus had a significantly higher prevalence of hearing disorders such as conductive hearing loss, a C5-dip, and NIHL.Multivariative logistic regression indicated that past history of ear disease, working and military service exposure to noise were independently associated with tinnitus. The adjusted odds ratio estimates for tinnitus were 3.0 times greater (95%CI 1.4-6.4) for the group with a past history of ear diseases,2.3 times greater (95%CI 1.0-5.0) for the military noise exposed group,and 4.5 times greater (95%CI 1.8-11.1) for the working noise exposed group. CONCLUSIONS: The results provide evidence that reports of tinnitus at the time of the annual audiometric testing may be useful in identifying workers at greater risk of developing significant shifts in their hearing thresholds. An awareness of the possible occurrence of tinnitus may encourage workers to cooperate more actively in a company's hearing conservation program.

Analysis of Work-Related Musculoskeletal Disease by Approved Korea Labor Welfare Corporation in 1999 / 대한산업의학회지

OBJECTIVES: The purpose of this study was to analyze the characteristics of workrelated musculoskeletal diseases, as listed by the Korea Labor Welfare Corporation (KLWC). METHODS: Using the database of the KLWC, we collected information from 410 approved occupational musculoskeletal disease cases, which occurred between 1 January and 31 December 1999 and were approved by 30 June in 2000. We investigated the characteristics of the disease using a mail survey and telephone interviews. The characteristics we investigated included : sex, age, disease-related working duration, process of disease occurrence, type of enterprises, etc. RESULTS: Men accounted for 75.6 % (310 workers) of the approved cases. The most common age group was 30-39 years (n=143, 34.9 %). The mean disease-related working duration was 5.7 years, and the most commonly had a work-duration of 1-5 years (n=108, 36.0 %). The major industrial types of enterprise were manufacturing (235 workers, 57.3 %), transportation (46 workers, 11.2 %), and construction (25 workers, 6.1 %). Within the manufacturing industry, the most common was motor vehicles and trailers manufacturing. Within the group, the most common jobs were plant or machine operators and assemblers (129 workers, 36.5 %), elementary occupations (90 workers, 25.5 %), and craft and related trades workers (63 workers, 17.8 %). The majority of the diseases involved lumbar problems (232 cases, 54.7 %), neck and upper extremity diseases (183 cases, 43.2 %) and lower extremity diseases (9 cases, 2.1 %). In the cases of lumbar disease, the mean age and working duration was 36.5 years and 4.7 years, respectively. Fifty-four cases of lumbar diseases were due to repetitive work and 89 due to non-repetitive work. Bad posture at work was the most common cause for those doing repetitive work(23 cases), and lifting the most common cause of problems in the non-repetitive work cases (27). CONCLUSIONS: We were able to elucidate the characteristics of workers with approved occupational musculoskeletal disease through this study. Many approved cases occurred in women, and workers performing repetitive work, of these herniated nucleus pulposus occurred in many workers performing simple repetitive works without serious external forces. This suggests that a prevention policy for occupational musculoskeletal disease must be established, to focusing on the above-mentioned high-risk groups.

Factors Affecting the Use of Medical Services by Workers with Respiratory Diseases / 예방의학회지

OBJECTIVES: To identify the relationship between the use of medical services by workers with three types of respiratory diseases (total respiratory diseases, acute upper respiratory infections and chronic lower respiratory diseases) and exposure to hazardous agents after controlling for other factors affecting medical services use, such as characteristics of the enterprises (scale, industry type) and employee demographics (sex, age). METHODS: The study population comprised 28,882 workers who had undergone general or special medical examinations at the industrial health center at least once between Jan 1995 and Dec 1997 and had possessed medical insurance during the period. We combined medical examination data with medical insurance data in order to analyze the relationship between exposure to hazardous agents and respiratory diseases. RESULTS: Among the 28,882 study subjects, 17,454 employees (60.4%) used medical services more than once during 3-year study period, owing to more than one kind of respiratory diseases. In logistic regression analysis, sex, age and the size of the enterprises proved to be significant variables on the use of medical services for all three types of respiratory disease: The use of medical services increased with employee age. Women used more medical services than men and the employees in the large-scale enterprises used more services than employees in small-scale enterprises. However, exposure to dust or organic solvents did not affect medical service use due to total respiratory diseases or acute upper respiratory infections. Only in the case of chronic lower respiratory diseases did workers exposed to dusts (OR=1.12, 95% CI=1.01 -1.24) or organic solvents (OR=1.19, 95% CI=1.05-1.35) use more medical services than those not exposed. CONCLUSIONS: Workers exposed to dusts or organic solvents are particularly apt to suffer from chronic lower respiratory diseases and use medical services more often than those not exposed. That is, chronic exposure to hazardous agents such as dusts and organic solvents is believed to be harmful and to cause respiratory symptoms and diseases.

Influence of Shiftwork Duration on Blood Pressure and Heart Rate Variability in Short Rotating 8-hour Shiftworkers / 대한산업의학회지

OBJECTIVES: This study was performed to investigate the chronic health effect of shiftwork on cardiovascular system. METHODS: We checked blood pressure(BP) and heart rate variability(HRV) at every shift on 134 male workers whose shift type was 8-hour and short rotating of 3 days shift interval. As confoundings, job stress was measured by Karasek's JCQ 49 items questionnaire and circardian type was assessed by morningness-eveningness questionnaire. Smoking and alcohol drinking habit, marital status and past medical history were also acquired. We used the method of repeated measured data analysis with mixed model to show the association between shiftwork duration and BP or HRV. RESULTS: Average age of workers was 29 years olds(range 25~44). Among them, 77.9 % were current smokers, 50 % were the passive type of job strain in Karasek's model. Mean shiftwork duration was 5.21 years(range 5.4 months~10 years). In circadian type, no one was definitely morning type or definitely evening type. In multivariate analyses adjusted by age, job strain, shift, circadian rhythm and smoking, blood pressure were showed significantly increasing trends according to shiftwork duration in both systolic and diastolic(p<0.05). Heart rate variability were also showed significantly decreasing trends according to shiftwork duration in both parasympathetic and sympathetic functions(p<0.05). CONCLUSIONS: The results of this studs suggests the chronic negative health effect of shiftwork on cardiovascular system.

Occupational Cancer in Korea in the 1990s / 대한산업의학회지

The proportion of cancer as a cause of death in Korean has been continuously increasing. In 2000, 24 %(59,020 of 247,346) of deaths were caused by cancer. Occupational exposure would have contributed to the development of some cancers. It would have accounted for more than 2,000 cancers in a year if 4% of all cancer or 10% of lung cancer was regarded as arising from the work environment. However, occupational cancer has not been reported as much as expected. The first case of occupational cancer reported officially was mesothelioma caused by asbestos exposure at an asbestos textile industry in 1992. Following the report, many cases of occupational cancers have been reported such as lung cancer due to exposure to asbestos, chromium, exhaust gases, coke oven emissions, and silica, as well as leukemia due to exposure to benzene or other solvent and bladder cancer arising from exposure to benzidine salts. The Health Examination for retirees has been conducted since 1992 in order to detect occupational cancer early in workers who have been exposed to 11 carcinogenic substances. However, to date no occupational cancer has been detected through the Retirees' Health Examination. The Korea Labor Welfare Corporation(KLWC) has referred 108 claims for occupational cancer to the Korea Occupational Safety and Health Agency(KOSHA) between 1992 and 2000. Thirty-three cases were accepted, including 14 cases of lung cancer, eight cases of hematopoietic cancer and six cases of mesothelioma. KLWC has accepted the claim for primary lung cancer developed with pneumoconiosis as an occupational cancer, of which there were 31 cases in 1999 and 61 cases in 2000. In conclusion, special attention is required to detect occupational cancer due to their long latency period and the fact they are usually found after retirement.

Analysis of Occupational Disease by Approved Korea Labor Welfare Corporation in 1999 / 대한산업의학회지

OBJECTIVES: The purpose of this study is to analyze the characteristics of occupational diseases listed by Korea Labor Welfare Corporation(KLWC). METHODS: Using the database of the KLWC, we collected 575 approved occupational disease cases occurring between 1 January and 31 December 1999 and approved by the thirtieth June in 2000. We investigated the characteristics(sex, age, occupational history, kinds of occupational disease, exposure material, type of enterprises, etc.) of occupational disease using a mail survey and telephone interviews. RESULTS: Men accounted for 88.9 %(511 workers) of the approved cases. 56 cases(9.7%) died of occupational disease. The most common age group was 50~59 years of age(n=217, 37.7 %). The proportion of workers with grater than ten years disease related working condition exposure were 195(49.0 %). The majority of diseases were respiratory problems(211 workers, 22.4 %), occupational hearing loss(149 workers, 25.9 %), infectious disease(69 workers, 12.0 %), intoxication(60 workers, 10.4 %), skin disease(29 workers, 5.0 %) and cancer(17 workers, 3.0 %). The causal hazardous agents were dusts(209 cases, 36.3 %), physical agents(157 cases, 27.3 %), chemical agents(89 cases, 16.3 %), biological agents(82 cases, 14.3 %) and workrelated agents(34 cases, 5.9 %). The major types of enterprise were manufacturing(262 workers, 45.6 %), mining and quarrying(174 workers, 30.3 %), public administration(42 workers, 7.3 %) and the health care industry(28 workers, 4.9 %). The kinds of job included craft and related trades workers(285 workers, 49.6 %), plant or machine operators and assemblers(139 workers, 24.2 %), elementary occupations(72 workers, 12.5 %) and professionals(28 workers, 4.9 %). CONCLUSIONS: We were able to elucidate the kinds of occupational disease and the characteristics of workers through this study. Many approved cases occurred among nonmanufacturing and non-mining workers and the kinds of disease were varied. This suggests that management policy must be established to prevent occupational disease occurring among workers in the above type of industries.

An Analysis of Industrial Accidents in an Automobile Factory / 대한산업의학회지

OBJECTIVES: To know the present conditions of industrial accidents in automobile factories in Korea and make the basic materials essential to prevention of industrial accidents METHODS: We reviewed and analyzed the records of industrial accidents occurred in an automobile factory in 1997 by time of occurrence, job categories(fixed production, skilled trades, mechanical material handling, and clerical 8r technical), type of injury, kind of accident, and location of injury. RESULTS: 1. By age groups, the accident rate was the highest in age 45-49(1.6 %o) followed by age 35-39(1.3 %), 40-44(0.9 %), 30-34(0.9 %), 25-29(0.6 %), and 20-24(0.4 %) and by working duration, it was highest in group of experience over 25 years, and so we could see that the more age or working duration increases the more accident rate increases. 2. By work time, the accident rate was the highest in 10-11 a.m. (21.4 %) followed by 2-3 p.m. (17.9%). By the day of the week, it was as follows, Friday(20.5%) Wednesday (17. 9%), Monday (16. 2 %), Thesday (15. 4 %), Saturday (12. 0 %), Thursday(11.1 %), Sunday(6.8 %) in order. By the month, it was high in May(17.9 %), March(11.1 %), and April(11.1 %) followed by August(10.3 %) and January(9.4 %), so we could see it was high in spring. 3. The most frequent injury was in the back by 41.0 % followed by 17 cases in fingers(14.5 %), legs(9.4 %), hands(7.7 %), head(6.0 %) in order. And by the type of injuries, the sprain was most frequent by 38. 5% followed by fracture(22. 2 %, lumbar HNP(11.1 %), and contusion(9.4 %) in order. The causes of accident were handling heavy materials(34.2 %), upset(17.1 %), stenosis(16.2 %), and falling(6.8 %) in order. CONCLUSIONS: By the above results, to prevent the industrial accidents in automobile factories in Korea, preventive activities for handling heavy materials and back injury, and continuous industrial education are necessary.

Analysis of Korean Analytical Quality Assurance Program for the Special Health Examination from 1995 to 1999 / 대한산업의학회지

OBJECTIVE: The accuracy of analytical results of blood and urine heavy metals came out to the main issue on occupational health from late eighties. The discrepancy of the results for same samples from different laboratories made the diagnosis for occupational diseases be unreliable. Therefore, a quality control program for analysis of samples taken from workplace had been introduced in Korea since 1992. This study aims to show the quality control program f'or analysis of blood and urine samples and its proficient rates from 1992 to 1999 and to know how they have been being used in occupational health. METHODS: The quality control program runs twice a year with mandatory items of blood lead and urine hippuvic acid and voluntary items of blood cadmium and manganese and urine mandellic acid and methyl hippuric acid. Participant laboratories are receiving three levels for each items and two out of three samples have to be qualified for being a proficient laboratory for the item. The acceptable range of blood lead and urine hippuric acid is +/-15% and that of the others is within 3 SD(standard deviation) from the reference values. RESULTS: The proficient rates of blood lead and urine hippuric acid was 89%, 90%, repectively, however those of the other voluntary items have been from 51% to 62%. The proficient rates of urine mercury and urine N-methylformamide(NMF), which are introduced since 1999, were very poor. Urine hippuric acid and blood lead were analyzed frequently for the purpose of biological monitoring conducting by special health examination organizations. Urine and blood manganese and urine metabolites of trichloroethylene, urine phenol, methylhippuric acid and cadmium were followed. CONCLUSIONS: In conclusion, the quality control program for biological monitoring has dramatically improve the ability of analysing blood and urine samples and eventually contributes to diagnose occupational diseases and to prevent occupational poisoning. However, some biological monitoring data, such as urine manganese, mercury and NMF, have been still reported from laboratories that were not accepted as a proficient laboratory.

Cognitive Impairment and Peripheral Neuropathy by Mixed Organic Solvents in Spray Painters Working in a Shipbuilding Industry

BACKGROUND: Exposure to organic solvents becomes a common problem to workers of heavy industries in Korea. A number of volatile organic solvents which are frequently used in painting can cause various derangements of the nervous system, especially cognitive impairments and peripheral neuropathy. METHODS: This study was carried out on 190 workers as a control group who had never been exposed to organic solvents and on 674 spray painters with long-term exposure to organic solvent mixtures. The major components of organic solvent mixtures were determined. All subjects underwent neurological examination as well as routine physical check-up after completing questionnaires on general, musculoskeletal, neuropsychiatric and neurological systems. Subjects with abnormal findings on neurological examination related with the exposure of organic solvent mixtures took further neuropsychological and neurophysiological tests. RESULTS: The prevalence rates of cognitive impairments and of peripheral neuropathy in the exposed group were significantly higher than the control group (9.5% vs 2.1% and 2.1% vs 0%, respectively). High exposure group (more than 2.64 of cumulative exposure index, CEI) showed also higher prevalence of cognitive impairments and of peripheral neuropathy than low exposure group (cognitive impairments; 12.3% vs 6.4%, peripheral neuropathy; 2.3% vs 1.8%). Most common cognitive impairments were attentional deficit, and abnormal sense on the extremities or face was most common symptom of the peripheral nervous system. CONCLUSION: This study is the first large-scale, case-control study extensively evaluating cognitive impairments and peripheral neuropathy related with volatile organic solvent mixtures in spray painters working in a shipbuilding industry in Korea. The results show that the prevalence rates of cognitive impairments and of peripheral neuropathy are relatively low, but clearly related with the exposure extent of organic solvents.

The Prediction Model of the Number of Industrial Injured Persons Using Data Mining / 대한산업의학회지

OBJECTIVES: This study is to see the transition and pattern of the industrial iureal worker, and to develop the prediction model. METHODS: The data of the study are based on the samples from data-warehouse of Occupational Safety & Health Research Institute and are summed monthly from Jan 1986 to Dec 1999. This study data used data mart and Meta data from DW in KOSHA. The prediction model of the injured worker in Industry is designed by using a winters time series method after data preparing (i. e. sample, explore, modify) from DW. RESULTS: Thls predicted model obtained Winters-method multiplicative in exponential smoothing among applied all models, after the tlme series (total 163 months). It showed that the prediction power was 95.5 %. CONCLUSIONS: In the process of exploring the data, totally the rate of industrial injureal workers reduced, and in the yearly circulation, in February and September the number is the lowest but in June, July, October and November the higher. The number of monthly average injureal workers is 8709 (95 % confidence interval 8277, 9140). From the developed prediction model, since Aug 1999 the industrial injureal worker reduced rapidly in Dec 1999 and first period of 2000. But In second period of 2000 the number of the injured workers is increasing. To conclude, as the total economic situation is becoming better in 2000 than In 1999, its is supposed that the injured workers will increase more than the predictive injured workers because of the increase of production rate and labor force.

Analysis of Claimed Cases as an Occupational Disease at Korea Occupational Safety and Health Agency from 1992 to 1999 / 대한산업의학회지

OBJECTIVES: Pneumoconisis and noise-induced hearing loss(NIHL) have been reported as main occupational diseases by the Special Health Examination. The Industrial Accident Compensation Insurance has reported various work-related diseases, however, these two diseases occupied almost a half of compensated cases. Therefore, it was not well known about the status of occupational diseases other than pneumoconiosis, NIHL, and cardiocerebrovascular accident(CVA). This study was conducted to analyze claimed cases as an occupational disease, that was requested to the Korea Industrial Safety and Health Agency (KOSHA). METHODS: The local office of the Korea Labor Welfare Corporation(KLWC) has asked the KOSHA for confirmation of claimed cases as an occupational disease. We analyzed 379 cases requested from KLWC, the Ministry of Labor, employers, unions and occupational health agencies from 1992 to 1999. RESULTS: Male was 80. 7 % of the requested cases. Their mean age was 42 years old and 75. 5 % of them were more than 35 years old. The requested cases were increased rapidly from 25 cases in 1992 to 108 cases in 1999 and the accept rate was 50. 7 %. The majority of requested cases were respiratory diseases(22.4 %), cancers(18.5 %), Neuropsychiatric problems (14. 5 %), and musculoskeletal problems (13. 5 %). The accept rate was high in reproductive, respiratory, musculoskeletal and digestive disorders and low in neuropsychiatric, renal and otologic problems and occupational cancers. 73. 6 % of them were caused by chemical agents, especially 28. 5 % were by organic solvents. 67 % of them were clinically confirmed at university hospitals. A half of the cases were from KyongIn area, even the request came from the whole country. CONCLUSIONS: A claim was common in workers whose age was over 35 years old and exposure history was over 10 years. The respiratory diseases and neuropsychiatric disorders were still main problems in occupational health and occupational cancers was increasing even though its accept rate was not high yet.

Understanding the Occurrence of Lung Cancer in Foundry Workers through Health Insurance Data / 예방의학회지

CONCLUSIONS: To investigate the difference in the occurrence of lung cancer between foundry workers and non-foundry workers by comparing the number of workers diagnosed with lung cancer through health insurance data. METHODS: The study population was comprised of 28,884 workers who had undergone at least one general or special medical examination between January 1995 and December 1997 at the occupational health center. All of the subjects had health insurance during this period. We combined the medical examination data with the health insurance data to compare the number of foundry workers diagnosed with lung cancer and the number of non-foundry workers diagnosed with lung cancer. RESULTS: Seven workers were diagnosed with lung cancer among the 1,591 foundry workers, compared to twelve workers among the 27,293 non-foundry workers (odds ratio: 10.04, 95% confidence interval: 3.95-25.55). The seven foundry workers diagnosed with lung cancer were all exposed to dust, and six out these seven workers were engaged in finishing or shake-out processes. CONCLUSIONS: Although the information for this study was obtained from health insurance data, which has limitations such as accuracy and completeness, the number of foundry workers diagnosed with lung cancer was significantly higher than that of non-foundry workers. Therefore, a well-designed cohort study should be followed to confirm the higher lung cancer rates in foundry workers.

Occupational Hazards of Medical Workers : Present Situation and Countermeasure

No abstract available.

Health Effects of Aircraft Noise on Residents Living Near an Airport / 대한산업의학회지

Objectives ; This study was conducted to reveal the health effects of aircraft noise on the residents live near the military airport. METHODS: We sampled systematically 87 residents as the high exposed group, 58 residents as the low exposed group according to the geographical distance from the airport. We also sampled 67 residents as the control group lived far from the airport. Noise levels were measured for conform the exposures. Self-administered questionnaires for symptoms, air conduction hearing threshold level, blood pressure blood cholesterol with health examinations, and SCL-90-R were introduced to get the data from the residents. RESULTS: The Ld/n at the area near the airport was 72.4 dB, however that of control area was 67. 7 dB. The value of pure tone average, high pure tone average, and threshold of 4,000 Hz were decreased with exposure level significantly. Linear regression analysis showed that the noise exposure level of the airport was related to the hearing threshold at pure tone average, threshold of 4,000 Hz, and high pure tone average. The systemic and diastolic blood pressure showed dose-response relationship with noise exposure. The prevalence of hypertension was higher in exposed group, but not statistically significant. In linear regression, noise level was related to systolic and diastolic blood pressure with other variables such as age, sex, BMI (Body Mass Index), and family history of hypertension. SCL-90-R showed that exposed group had higher score significantly in neurotic and psychologic variable and felt the various somatic symptoms. CONCLUSIONS: These results suggest that aircraft noise would influence hearing loss at low frequencies as well as 4,000 Hz and higher frequencies, systolic and diastolic blood pressure, and psychological response.

Reading Agreement of Pneumoconiosis on Simple Chest Films / 대한산업의학회지

No abstract available.

Understanding and Management of Occupational Diseases

No abstract available.

Reactive Airways Dysfunction Syndrome (RADS) Due to Chlorine Gas Exposure / 대한산업의학회지

Reactive airways dysfunction syndrome (RADS) is a syndrome as a persistent bronchial hyperreactivity with asthmatic dyspnea which occurs after one or more inhalation exposures to a high concentration of irritant gasses, smokes or vapors in subjects who had preciously had no respiratory disease. We report a case of a 34 years old female worker suffering from reactive airways dysfunction syndrome who had been taking charge of guest room cleaning at a condominium. 7 months before, she inhaled high concentration of chlorine gas in confined and poor ventilated working space of bathroom at the condominium. As she was washing a bathroom with a bleaching agent (6 % sodium hypochlorite) without dilution, dyspnea, dizziness, headache, nausea, and coughing developed after work. She still suffer from dyspnea and coughing. All functional tests were normal except for methacholine challenge test which reveals bronchial hyperreactivity. She has some symptoms of dyspnea and coughing when exposed to perfume, cold air, and heavy work.