Impacts of Return-to-Work Type and Period on Job Retention in Workers with Occupational Injuries and Diseases

BACKGROUND: Despite the necessity of job retention in achieving return-to-work (RTW) goals, many workers leave their jobs after returning to work. The objective of this study was to examine the impacts of RTW type and period on job retention in Korean workers with occupational injuries and diseases. METHODS: Data were derived from the Panel Study of Worker's Compensation Insurance, including data from 2,000 systemically sampled workers who had finished recuperation in 2012; three waves of survey data were included in the analyses. Workers who returned to work (n = 1,610) were included in the analysis of the relationship between RTW type and job retention, and 664 workers who returned to their original workplaces were included in the analysis of the relationship between RTW period and job retention. The participants completed a questionnaire, and administrative data were provided by workers' compensation insurance. RESULTS: A Cox proportional-hazards regression analysis showed an increased hazard ratio (HR) for non-retention of 2.66 (95% confidence interval, 2.11–3.35) in reemployed workers compared to that in workers returning to their original workplaces. Among workers returning to their original workplaces, HRs for non-retention were increased in workers with a RTW period of 13–24 months (3.03 [1.52–6.04]) and > 24 months (5.33 [2.14–13.25]) compared to workers with a RTW period of ≤ 3 months. CONCLUSION: RTW type and period were significantly related to job retention, suggesting that policies for promoting job retention rate should be implemented.

The Association between Involuntary Smoking Exposure with Urine Cotinine Level and Blood Cadmium Level in General Non-Smoking Populations

Unintentional environmental exposure to toxicants is associated with an aggravated health status of the general population. Involuntary smoking (IS) exposure is one of the main routes to involuntary toxicants exposure. However, few studies have attempted to understand the environmental cadmium exposure by IS exposure in the general, non-smoking population. The purpose of the current study was to examine the relationship between blood cadmium level and IS level according to gender and age. We used the Korea National Health and Nutrition Examination Survey (KNHANES) IV–VI data that included heavy metal and urine cotinine sampling with IS exposure history. The final analysis comprised 3,493 adults (1,231 males and 2,262 females) and 395 adolescents (210 males and 185 females). Linear regression was performed to estimate the association between self-reported IS exposure with urine cotinine level and blood cadmium level in non-smokers with gender and age group stratification. In final regression model, the effect values (B) (standard errors [SE]) between blood cadmium and urine cotinine level in men was 0.0004 (0.0001) and 0.0006 (0.0002) in adults and adolescents, the B (SE) in women was 0.0006 (0.0002) and 0.0016 (0.0006) in adults and adolescents. Our study revealed, for the first time, a significant association between blood cadmium and IS exposure in non-smokers. Greater efforts are needed to improve environmental justices of the general population from IS, considering the severe harmful effects of involuntary exposure to even a low level of cadmium.

The Perceived Socioeconomic Status Is an Important Factor of Health Recovery for Victims of Occupational Accidents in Korea

We aimed to examine whether there is a correlation between the health recovery of industrial accident victims and their perceived socioeconomic status. Data were obtained from the first Panel Study of Worker's Compensation Insurance, which included 2,000 participants. We performed multivariate regression analysis and determined the odds ratios for participants with a subjectively lower socioeconomic status and for those with a subjectively lower middle socioeconomic status using 95% confidence intervals. An additional multivariate regression analysis yielded the odds ratios for participants with a subjectively lower socioeconomic status and those with a subjectively upper middle socioeconomic class using 95% confidence intervals. Of all participants, 299 reported a full recovery, whereas 1,701 did not. We examined the odds ratio (95% confidence intervals) for participants' health recovery according to their subjective socioeconomic status while controlling for sex, age, education, tobacco use, alcohol use, subjective state of health prior to the accident, chronic disease, employment duration, recovery period, accident type, disability status, disability rating, and economic participation. The odds of recovery in participants with a subjectively lower middle socioeconomic status were 1.707 times greater (1.264-2.305) than that of those with a subjectively lower socioeconomic status. Similarly, the odds of recovery in participants with a subjectively upper middle socioeconomic status were 3.124 times greater (1.795-5.438) than that of those with a subjectively lower socioeconomic status. Our findings indicate that participants' perceived socioeconomic disparities extend to disparities in their health status. The reinforcement of welfare measures is greatly needed to temper these disparities.

The Perceived Socioeconomic Status Is an Important Factor of Health Recovery for Victims of Occupational Accidents in Korea

We aimed to examine whether there is a correlation between the health recovery of industrial accident victims and their perceived socioeconomic status. Data were obtained from the first Panel Study of Worker's Compensation Insurance, which included 2,000 participants. We performed multivariate regression analysis and determined the odds ratios for participants with a subjectively lower socioeconomic status and for those with a subjectively lower middle socioeconomic status using 95% confidence intervals. An additional multivariate regression analysis yielded the odds ratios for participants with a subjectively lower socioeconomic status and those with a subjectively upper middle socioeconomic class using 95% confidence intervals. Of all participants, 299 reported a full recovery, whereas 1,701 did not. We examined the odds ratio (95% confidence intervals) for participants' health recovery according to their subjective socioeconomic status while controlling for sex, age, education, tobacco use, alcohol use, subjective state of health prior to the accident, chronic disease, employment duration, recovery period, accident type, disability status, disability rating, and economic participation. The odds of recovery in participants with a subjectively lower middle socioeconomic status were 1.707 times greater (1.264-2.305) than that of those with a subjectively lower socioeconomic status. Similarly, the odds of recovery in participants with a subjectively upper middle socioeconomic status were 3.124 times greater (1.795-5.438) than that of those with a subjectively lower socioeconomic status. Our findings indicate that participants' perceived socioeconomic disparities extend to disparities in their health status. The reinforcement of welfare measures is greatly needed to temper these disparities.

Workplace Violence Experienced by Substitute (Daeri) Drivers and Its Relationship to Depression in Korea

Workplace violence is related to various health effects including mental illness such as anxiety or depression. In this study, the relationship between the experience of workplace violence and depression in substitute drivers in Korea, namely, daeri drivers, was investigated. To assess workplace violence, questions regarding types and frequency of the experience of violence over the past year were asked to the daeri drivers. In order to assess the risk of depression, the Center for Epidemiological Studies Depression Scale was used. Odds ratios with 95% confidence intervals of depression were estimated using multiple logistic regression analysis. All of the daeri drivers had experienced instance of verbal violence while driving and 66 of the drivers (34.1%) had been in such a situation more than once in the past quarter of a year. Sixty-eight daeri drivers (42.2%) had experienced certain type of physical violence over the past year. Compared to daeri drivers who had experienced workplace verbal violence less than 4 times and who had not experienced workplace physical violence over the past year, higher odds ratio was observed in daeri drivers who had experienced workplace verbal violence or physical violence, more than 4 times and more than one time respectively, after adjustment. Experience of verbal or physical type of workplace violence over the past year increased the risk of depression in the daeri drivers. Because violence against drivers can compromise the safety of the driver, the customer, and all the passengers, it is imperative that the safety and health of daeri drivers be highlighted.

Case report of renal cell carcinoma in automobile manufacturing factory worker due to trichloroethylene exposure in Korea

BACKGROUND: The aim of this paper was report first case of renal cell carcinoma developed in a worker who worked in an automobile manufacture line which handles trichloroethylene in Korea. CASE PRESENTATION: To clarify the relationship between the onset of renal cell carcinoma in 52-years old male worker and the exposure to trichloroethylene, document studies and work environment measurement were done. Past work environment exposure data were reviewed and medical history and surgery records of the worker were also reviewed. The patient had no personal risk factor related to renal cell carcinoma except for his smoking habit of quarter a pack per day for twenty years, and since trichloroethylene was not part of measurement criteria, past work environment risk assessment data could not verify the exposure. The exposure level is deduced by analyzing material exposure level of work environments which has similar processes in data from revised research of chemical exposure standard and work environment validity assessment. Evaluation Committee of Epidemiologic Survey decided that there are relevant relationship between the exposure and the disease, though we do not have exact data during that period, most experts agree that in every factories they used trichloroethylene without any direction. CONCLUSIONS: From the relevant medical history and the results of the usage of trichloroethylene in the relevant industries, and initial discovery of renal cell carcinoma at health inspection sonogram in 2001, it can be concluded that suggests significant causal relationship between the exposure to trichloroethylene and renal cell carcinoma onset, thus reporting it to be the first domestic case declared to be occupational disease.

Factors related to the physician and the employer influencing successful return to work in Korea: results from the first panel study of workers' compensation insurance (PSWCI)

OBJECTIVES: This study aims to investigate associated factors including the physician and the employer of successful return to work (RTW) in occupationally injured workers. METHODS: This study is based on the first panel study of workers' compensation insurance (PSWCI), published in June 2014. The PSWCI is a sample survey of occupationally injured workers who completed medical care in 2012 (89,921 people). A total of 2000 subjects were sampled based on sex, age, nine metropolitan-based regions, disability ratings, duration of rehabilitation, and whether vocational rehabilitation service was used. We divided the study population into two groups: return to work (RTW) group (job retention, reemployment, unpaid family worker, and self-employment), and non-RTW group (joblessness and economical inactivity). The odds ratios (ORs) and 95 % confidence intervals (CI) related to differences in basic characteristics, part of physician and employer-related factors between those who succeeded to RTW and those who did not were measured using multivariable logistic regression model. RESULTS: The success of RTW is 70.6 % (n = 1412) among participants. The ORs (95 % CI) of the participants belonging to RTW who received periodic recovery assessment from the medical care institution and the physician are 1.51 (1.07-2.13). The ORs (95 % CI) are 1.68 (1.05-2.69) for the RTW group who received work ability assessment and referral for vocational return. When the employer maintains the relationship with the occupationally injured worker, the worker has 1.39 times higher odds (95 % CI: 1.41-2.26) of the RTW group compared to the non-RTW group. CONCLUSIONS: The physician and the employer have a significant impact on the RTW.

The association between concealing emotions at work and medical utilization in Korea

OBJECTIVES: We aimed to investigate the association between concealing emotions at work and medical utilization. METHODS: Data from the 2007-2009 4th Korea National Health and Nutrition Examination Survey (KNHANES IV) was used, 7,094 participants (3,837 males, 3,257 females) aged between 20 and 54 who were economically active and completed all necessary questionnaire items were included. Odds ratios (ORs) and 95% confidence intervals (95% CI) for differences in hospitalization, outpatient visits, and pharmaceutical drug use between those who concealed their emotions and those who did not were investigated using logistic regression models with and without gender stratification. RESULTS: Among those who concealed their emotions (n = 2,763), 47.4% were females, and 50.1% had chronic disease. In addition, 9.7% of the concealing emotions group had been hospitalized within the last year, 24.8% had been outpatients in the last two weeks, and 28.3% had used pharmaceutical drugs in the last two weeks. All ORs represent the odds of belonging to the concealing emotions group over the non-concealing emotions group. After adjustment for individual, occupational, socioeconomic and disease factors, the adjusted ORs (95% CI) in hospitalization are 1.29 (1.08 ~ 1.53) in the total population, 1.25 (0.98 ~ 1.60) in males and 1.30 (1.02 ~ 1.66) in females, in outpatient visits are 1.15 (1.02 ~ 1.29) in the total population, 1.05 (0.88 ~ 1.24) in males and 1.25 (1.06 ~ 1.47) in females and in pharmaceutical drug use are 1.12 (1.01 ~ 1.25) in the total population, 1.08 (0.92 ~ 1.27) in males and 1.14 (0.98 ~ 1.33) in females. CONCLUSIONS: Those who concealed their emotions at work were more likely to use medical services. Moreover, the health effects of concealing emotions at work might be more detrimental in women than in men.

A case of multiple myeloma in a poultry worker

BACKGROUND: Livestock breeders including poultry workers are exposed to various agricultural chemicals including pesticides and/or organic solvents. Multiple myeloma is a rare disease in Korea, and few reports have investigated the influence of occupational exposures on multiple myeloma occurrence. CASE PRESENTATION: A 61-year-old male poultry farm worker presented with bone pain and generalized weakness. A bone marrow biopsy was performed, and he was diagnosed with multiple myeloma. The patient had worked in a poultry farm for 16 years and was exposed to various pesticides and organic solvents such as formaldehyde without any proper personal protective equipment. Results of the work reenactment revealed that the concentration of formaldehyde (17.53 ppm) greatly exceeded the time-weighted average (0.5 ppm) and short-term exposure limit (1.0 ppm) suggested in the Korean Industrial Safety and Health Act. CONCLUSIONS: This case report suggests that poultry workers may be exposed to high levels of various hazardous chemicals including pesticides and/or organic solvents. Numerous previous studies have suggested an association between multiple myeloma and exposure to agricultural chemicals; thus, multiple myeloma in this patient might have resulted from the prolonged, high exposure to these chemicals.

The Effect of Work Characteristics on Dermatologic Symptoms in Hairdressers

OBJECTIVES: Hairdressers in Korea perform various tasks and are exposed to health risk factors such as chemical substances or prolonged duration of wet work. The objective of this study is to provide descriptive statistics on the demographics and work characteristics of hairdressers in Korea and to identify work-related risk factors for dermatologic symptoms in hairdressers. METHODS: 1,054 hairdressers were selected and analyzed for this study. Independent variables were exposure to chemical substances, the training status of the hairdressers, and the main tasks required of them, and the dependent variable was the incidence of dermatologic symptoms. The relationships between work characteristics and dermatologic symptoms were evaluated by estimating odds ratios using multiple logistic regression analysis. RESULTS: Among the 1,054 study subjects, 212 hairdressers (20.1%) complained of dermatologic symptoms, and the symptoms were more prevalent in younger, unmarried or highly educated hairdressers. The main tasks that comprise the majority of the wet work were strictly determined by training status, since 96.5% of staff hairdressers identified washing as their main task, while only 1.5% and 2.0% of master and designer hairdressers, respectively, identified this as their main task. Multiple logistic regressions was performed to estimate odds ratios. While exposure to hairdressing chemicals showed no significant effect on the odds ratio for the incidence of dermatologic symptoms, higher odds ratios of dermatologic symptoms were shown in staff hairdressers (2.70, 95% CI: 1.32 - 5.51) and in hairdressers who perform washing as their main task (2.03, 95% CI: 1.22 - 3.37), after adjusting for general and work characteristics. CONCLUSIONS: This study showed that the training status and main tasks of hairdressers are closely related to each other and that the training status and main tasks of hairdressers are related to the incidence of dermatologic symptoms. This suggests that in the future, regulations on working conditions and health management guidelines for hairdressers should be established.

Allergic Diseases and Multiple Chemical Sensitivity in Korean Adults

PURPOSE: Multiple chemical sensitivity (MCS) is a clinical syndrome representing multi-organ and psychological symptoms caused by chronic exposure to various chemicals in low concentrations. We evaluated the prevalence and related factors of MCS targeting Korean adults using the Quick Environmental Exposure and Sensitivity Inventory (QEESI(c)). METHODS: A total of 446 participants were recruited from Severance Hospital. Participants underwent a questionnaire interview including questions on sociodemographic factors, occupational and environmental factors, allergic diseases, and the QEESI(c). Among them, 379 participants completed the questionnaire and the QEESI(c). According to the QEESI(c) interpretation results, participants were divided into very suggestive (VS) group and less suggestive (LS) group. RESULTS: The estimated prevalence of MCS was higher in allergic patients than non-allergic participants (19.7% and 11.3%, respectively, P=0.04). In the multivariate logistic regression analysis, ages of 30-39 (OR, 2.94; 95% CI, 1.25-6.95) and those of 40-49 (OR, 2.51; 95% CI, 1.02-6.21) were significantly related to MCS compared to those aged less than 30 years. Female sex (OR, 2.16; 95% CI, 1.11-4.18), experience of dwelling in a new house (OR, 2.05; 95% CI, 1.04-4.03), and atopic dermatitis (OR, 1.95; 95% CI, 1.04-3.69) were also significantly related to MCS. However, only age of 30-39 in the allergic group was significant in the stratified analysis. CONCLUSIONS: The estimated prevalence of MCS was higher among allergic patients than non-allergic participants. People with experience of dwelling in a new house and atopic dermatitis were more at risk of being intolerant to chemicals. Further studies to provide the nationally representative prevalence data and clarify risk factors and mechanisms of MCS are required.

Two Cases of Lung Cancer in Foundry Workers

BACKGROUND: Iron and steel foundry workers are exposed to various toxic and carcinogenic substances including crystalline silica, polycyclic aromatic hydrocarbons, and arsenic. Studies have been conducted on lung cancer in iron and steel founding workers and the concentration of crystalline silica in foundries; however, the concentration of crystalline silica and cases of lung cancer in a single foundry has never been reported in Korea. Therefore, the authors report two cases of lung cancer and concentration of crystalline silica by the X-ray diffraction method. CASE PRESENTATION: A 55-year-old blasting and grinding worker who worked in a foundry for 33 years was diagnosed with lung cancer. Another 64-year-old forklift driver who worked in foundries for 39 years was also diagnosed with lung cancer. Shot blast operatives were exposed to the highest level of respirable quartz (0.412 mg/m3), and a forklift driver was exposed to 0.223 mg/m3. CONCLUSIONS: The lung cancer of the two workers is very likely due to occupationally related exposure given their occupational history, the level of exposure to crystalline silica, and epidemiologic evidence. Further studies on the concentration of crystalline silica in foundries and techniques to reduce the crystalline silica concentration are required.

Radiotechnologists and Radiation Exposure from PET and PET/CT Systems / 대한산업의학회지

OBJECTIVES: In this study, radiotechnologists who work performing PET and PET/CT methodologies were analyzed in order to find the cause for the differences in radiation exposure as they applied to general characteristics, work characteristics, knowledge, and exposure recognition or conduct. METHODS: From April 15th, 2010 to May 14th, 2010, we conducted a retrospective analysis on 80 radiotechnologists using data garnered from their individual general characteristics, work characteristics, knowledge, and exposure recognition or conduct. Their average annual radiation exposure dosages were measured using a thermoluminescence dosimeter. A multiple regression analysis was performed as a statistical tool. RESULTS: Regarding the general PET and PET/CT characteristics, when the work experience was short, the exposure dose was higher. The factors of age, marriage, work experience in nuclear medicine, PET, PET/CT, and sex were found to have statistically significant effects. The knowledge, recognition, and conduct factors for the radiotechnologists were affected by unsecure radiation exposure at the moment of carrying, unsecure radiation exposure at the moment of injection, the application of protection at the moment of injection, and the use of auto distributor. It was found that, the use of an auto distributor, efforts in reducing the radiation exposure, unsecure exposure when with a patient, and the application of protective procedures at the moment of injection affected the overall factor of radiotechnologists radiation exposure dose. CONCLUSIONS: We believe that if radiotechnologists would reduce their radiation exposure by using auto distributors, make efforts to reduce the chance of exposure, and be conscious of radiation, they would be able to reduce the radiation exposure dose even during unavoidable circumstances.

A Workplace Cardiovascular Health Promotion Program and its Short-term Health Effects / 대한산업의학회지

OBJECTIVES: Cardiovascular disease is the leading cause of death and a major source of workers' compensation claims in Korea. Since 2000 the Korea Occupational Safety and Health Agency (KOSHA), working through local occupational health institutions, has supported cardiovascular disease prevention programs at a number of companies in Korea. The purpose of this study was to assess the short-term effects of this effort. METHODS: A total of 11,077 workers at risk were enrolled in the workplace cardiovascular disease prevention program and 5,902 workers (53.3%) completed the 1-year course during 2007. The program consisted of a medical checkup and health counseling for the workers by occupational health nurses. The guidelines for this prevention program were adopted from KOSHA Code H-11-2004. To determine the program's effectiveness, the workers' risks for cardiovascular disease were assessed before and one year after completion of the program. RESULTS: The intervention led to significant reductions in the mean systolic and diastolic blood pressures of 4.9 mmHg and 3.1 mmHg, respectively. Mean total cholesterol and BMI were also reduced significantly by 8.4 g/dl and 0.1 kg/m2. The rate of smoking was decreased by 6.0% and the percentage of workers engaging in regular exercise was increased by 23.1%. Of the 3,530 workers with the low risk and above, the overall cardiovascular risk was improved in 1,734 (49.1%) of them. CONCLUSIONS: The cardiovascular disease prevention program supported by the Korea Occupational Safety and Health Agency reduces cardiovascular diseases risks among workers and may improve the health status of workers in Korea.

Relationship between Job Stress and Turnover of Registered Nurses in a University Hospital / 대한산업의학회지

OBJECTIVES: This study was performed to investigate the relationship between job stress and the type of turnover of registered nurses in a university hospital. METHODS: A total of 553 registered nurses who left the hospital between 1994 and 2005 were surveyed, and aninterview record and self-administered questionnaire completed at the time of the turnover were used to assess the relationship. Job stress was categorized into four sub-scales (factor I: insufficient work authority and lack of autonomy, factor II: work overload and time urgency, factor III: interpersonal conflict and communication problems, and factor IV: role strain and ambiguity) using factor analysis. The type of turnover was classified into two categories: voluntary and involuntary. SPSS (version 11.0) was used for the statistical analyses. RESULTS: The direct cause of the turnover was getting a new job, and the nurses in the voluntary turnover group were younger and less experienced than those in the involuntary turnover group. The discriminant analysis findings indicated that the determinant factors affecting the type of turnover were marital status, factor I (insufficient work authority and lack of autonomy), factor II (work overload and time urgency), educational background, and the intention to get a new job. Meanwhile, the voluntary turnover was associated with marital status (single), insufficient work authority and lack of autonomy, high educational background, the intention to get a new job, and low work overload and time urgency. CONCLUSIONS: Job stress played a crucial role in the turnover of the registered nurses, and some job stressors such as insufficient work authority and lack of autonomy, work overload and time urgency were more related to the type of turnover. These results confirm the necessity for a management program or job redesign to eliminate or reduce job stressors which lead to turnover such as insufficient work authority, lack of autonomy, work overload and time urgency. Furthermore, greater opportunities need to be provided for developing their careers. Finally, further research is required to elucidate the specific job stressors affecting the turnover of registered nurses.

Urinary Excretion of Thiodiglycolic Acid According to Sampling Time in Workers Exposed to Vinyl Chloride Monomer / 대한산업의학회지

OBJECTIVES: The study was performed to investigate the changes of urinary thiodiglycolic acid (TDGA) concentration in workers exposed to vinyl chloride monomer (VCM) according to the time of sampling urine. METHODS: The personal exposure to airborne VCM was assessed and urinary TDGA concentration was sampled in 31 workers employed in a VCM and polyvinyl chloride (PVC) manufacturing factory. Urinary TDGA was sampled three times: before the start of the shift after 3 days off (TDGA1), after the end of the first-day shift (TDGA2) and before starting the following day shift after completing the oneday shift (TDGA3). Urinary TDGA in 30 workers who had not been exposed to airborne VCM was sampled after the end of the shift. A gas chromatography/pulsed flame photometric detector (GC/PFPD) was utilized to analyze TDGA concentration in urine after the urine was methylated with trimethylsilyldiazomethane(2.0M in diethyl ether). RESULTS: The creatinine level was 0.179+/-0.271 mg/g in the control workers and 0.218+/-0.443 mg/g in the workers before the start of the shift after 3 days off (TDGA1), showing no significant difference (p=0.7035). Urine samples were compared according to sampling time in order to investigate the change of urinary TDGA concentration in the case of continuous exposure to airborne VCM. In VCM-exposed workers, urinary creatinine concentration was 0.434+/-0.623 mg/g in TDGA2 and 0.767+/-1.056 mg/g in TDGA3, which indicated a gradual but significant increase (p=0.024). In terms of the statistical correlation between airborne VCM and urinary TDGA to evaluate exposure dose per day, of the three urinary TDGA concentrations, TDGA3 showed the highest degree of regression (R(2)=0.4215) with 8h-TWA airborne VCM concentration. CONCLUSION: Based on this result, the excretion half-life of urinary TDGA was assumed to be less than 3 days, because the concentration of urinary TDGA at 3 days after exposure to airborne VCM was decreased to the level of urinary TDGA concentration in the control workers. The concentration of urinary TDGA increased in the case of continuous shift, due to the accumulation of residual metabolites of TDGA. It was considered that TDGA3 can be applied as a useful biological index to evaluate the exposure dose of airborne VCM during one day because TDGA3 showed the highest correlation with the exposure dose of airborne VCM in the previous shift day.

Prevalence of Occupational Asthma in TDI-Exposed Workers / 대한산업의학회지

OBJECTIVES: This study was carried out to estimate the prevalence of isocyanate-induced occupational asthma in toluene diisocyanate (TDI) exposed workers. METHODS: We examined 170 workers who had been directly exposed to TDI through a medical questionnaire, physical examination, and pulmonary function test. Based on screening examination, workers with suspected occupational asthma were selected for further evaluation such as methacholine and TDI challenge tests. RESULTS: Eleven (6.9%) among 170 workers complained of symptoms of occupational asthma, and 7 among these 11 symptomatic workers showed positive responses to the methacholine challenge test (4.1%). One spray painter was confirmed as having the TDI induced occupational asthma following a positive response to TDI challenge test. CONCLUSIONS: The prevalence of TDI-induced asthma was at 0.58% was lower than that for former studies (2-20%). Improved workplace environment, lower level of TDI exposure compared to the past, and the healthy workers effect may have contributed to this low rate of asthma prevalence in workers with TDI exposure.

Analysis of Sufficient Conditions in Approving Cere b rovascular and Cardiovascular Disease as Occupational Disease / 대한산업의학회지

OBJECTIVES: This study was performed to analyze the factors that affect the decision to approve workers compensation claims for cerebrovascular and cardiovascular diseases and to analyze the worker characteristics. METHODS: Three hundred, sixty-nine cases were collected based on the workers compensation records of three Seoul and Incheon Regional centers of the Labor Welfare Corporation between 1998 and 1999. They contained the general characteristics, injury information and past medical histories. The x2-test and logistic regression were performed to investigate the factors affecting the approvals. Seventy-two survivors were surveyed by telephone for job stress. Job stress was surveyed in three parts: job demands, decision latitude and personal free time. RESULTS: Of the cases, 167 obtained approval from the Corporation; the others did not. Regardless of approval, 62% of all subjects had more than one of the cerebral and cardiovascular risk factors. Especially, 53.9% of subjects had hypertension. According to the logistic regression, the fatal cases had a higher approval rate (OR=26.4, CI=9.13-76.22). The cases with working condition change (OR=6.5, CI=3.45-12.07), accidents on worksite (OR=4.9, CI=2.39-10.07), female (OR=4.0, CI=1.21-13.3), accidents at night duty (OR=2.9, CI=.156-5.39), cases occurring on duty (OR=.25, CI=1.34-4.72) and cases without past disease history (OR=1.8, CI=1.02-3.36) also had higher approval rates. Telephone survey found that the approval rate increased with decreasing freedom of personal time schedule. However, the logistic regression revealed that job stress didnt affect the approvals. CONCLUSION: To prevent cerebrovascular and cardiovascular diseases, the most important aspect is to control hypertension which is the most common risk factor among the victims. Moreover, job stress and over working should be considered in the just approval of the workers compensation claims.

Pain Related Factors in Upper Extremities Among Hospital Workers Using Video Display Terminals / 대한산업의학회지

OBJECTIVES: This study was designed to quantify symptoms in the upper extremities and to identify the pain related factors among hospital workers using video display terminals. METHODS: The subject-group consisted of 138 employees working at a hospital using video display terminals. A structured questionnaire was used to estimate the participants' general characteristics, and job contents. Job stress was measured using Karaseks JCQ(Job Content Questionnaire). Pain in the upper extremities was identified according to the NIOSH symptoms survey criteria. Quantification was measured using Kim Chul's method. Pearson's Correlation analysis was used to identify validity in quantification. VAS(visual analog scale) was used to compare with this method. Multiple regression analyses elucidated the relationship between quantified pain and various work factors, such as job stress. Data were analysed with SAS 6.12 program. RESULTS: First, in quantification using Kim Chul's method, the correlation between modified PRS(pain rating score) and VAS was extremely high by 0.60(P<0.01), indicating the high validity of PRS. Second, the groups of high job demand, high job control, and females were related to an increased pain level. CONCLUSIONS: These results suggest that the self pain assessment method, PRS, is valuable and useful in analyzing occupational musculoskeletal symptoms. High demand, job control and gender may influence the levels of pain. Prospective studies about musculoskeletal disorder are required.

Effects of Ethanol and Phenobarbital on Hemoglobin Adducts Formation in Rats Exposed to Direct Black 38 / 예방의학회지

OBJECTIVES: To evaluate the effects on the formation of benzidine-hemoglobin, and benzidine metabolite-hemoglobin adducts, caused by pretreatment with the known xenobiotic metabolism effectors, ethanol and phenobarbital, in rats administered Direct Black 38 dye. METHODS: The experimental rats were divided into three groups: a control group, an ethanol group and a phenobarbital group. Rats were pretreated with ethanol (1g/kg) or phenobarbital (80mg/kg) 24 hours prior to the oral administration of Direct Black 38 (0.5mmol/kg), with the control group being administered the same amount of distilled water. Blood samples were obtained from the vena cava of 5 rats from each group prior to, and at 30 min, 3 h, 6 h, 9 h, 12 h, 24 h, 48 h, 72 h, 96 h, and 144 h following the oral administration of Direct Black 38. Directly after sampling the blood was separated into hemoglobin and plasma, with the adducts being converted into aromatic amines by basic hydrolysis. Hydrolyzed benzidiene, monoacetylbenzidine and 4-aminobiphenyl were analyzed by reverse-phase liquid chromatography with an electrochemical detector. The quantitative amount of the metabolites was expressed by the hemoglobin binding index (HBI). RESULTS: In the ethanol group, benzidine-, monoacetylben-zidine-, and 4-aminobiphenyl-HBI were increased to a greater extent than those in the control group. These results were attributed to the ethanol inducing N-hydroxylation, which is related to the formation of the hemoglobin adduct. In the phenobarbital group, all the HBIs, with the exception of the benzidine-HBI, were increased to a greater extent than those of the control group. These results were attributed to the phenobarbital inducing N-hydroxylation related to the formation of the hemoglobin adduct. The N-acetylation ratio was only increased with the phenobarbital pretreatment due to the lower benzidine-HBI of the phenobarbital group compared to those of the control and ethanol groups. The N-acetylation ratios for all groups were higher than 1 for the duration of the experimental period. Although the azo reduction was unaffected by the ethanol, it was inhibited by the phenobarbital. The ratio of the benzidine-HBI in the phenobarbital group was lower than those of the ethanol the control groups for the entire experiment. CONCLUSION: Our results indicate that both ethanol and phenobarbital increase the formation of adducts by the induction of N-hydroxylation, but also induced N-acetylation. Phenobarbital decreased the formation of benzidine-HBI due to the decrease of the azo reduction. These results suggest that the effects of ethanol and phenobarbital need to be considered in the biochemical monitoring of Direct Black 38.