Validation of the Work Engagement Scale-3, used in the 5th Korean Working Conditions Survey

Background@#The purpose of this study was to assess the reliability and validity of the 3-item version of the Work Engagement Scale (WES-3), which is based on the Job DemandsResources (JD-R) model and was used in the 5 th Korean Working Conditions Survey (KWCS). @*Methods@#This study used data from the 5th KWCS (n = 50,205), which was conducted in 2017 with a sample of the Korean working population. The survey gathered comprehensive information on working conditions to define workforce changes and the quality of work and life. The reliability and internal consistency of the WES-3 were assessed using the corrected item-total correlation and Cronbach's alpha coefficient. Confirmatory factor analysis (CFA) was used to test the construct validity of work engagement. The convergent validity was assessed using the correlation with the WHO-5 well-being index. Correlations between work engagement and JD-R factors were also calculated. @*Results@#The Cronbach's alpha for work engagement was 0.776, indicating acceptable internal consistency. The model comprising 3 work engagement and 2 burnout items showed an excellent fit (χ2 : 382.05, Tucker-Lewis index: 0.984, comparative fit index: 0.994, root mean square error of approximation: 0.043). The convergent validity was significant (correlation coefficient: 0.42). Correlations with burnout and job demands were negligible, whereas correlations with job resources and job satisfaction were weakly positive. @*Conclusions@#The results of our study confirm that the WES-3 has acceptable reliability and validity.

Validation of the Work Engagement Scale-3, used in the 5th Korean Working Conditions Survey

Background@#The purpose of this study was to assess the reliability and validity of the 3-item version of the Work Engagement Scale (WES-3), which is based on the Job DemandsResources (JD-R) model and was used in the 5 th Korean Working Conditions Survey (KWCS). @*Methods@#This study used data from the 5th KWCS (n = 50,205), which was conducted in 2017 with a sample of the Korean working population. The survey gathered comprehensive information on working conditions to define workforce changes and the quality of work and life. The reliability and internal consistency of the WES-3 were assessed using the corrected item-total correlation and Cronbach's alpha coefficient. Confirmatory factor analysis (CFA) was used to test the construct validity of work engagement. The convergent validity was assessed using the correlation with the WHO-5 well-being index. Correlations between work engagement and JD-R factors were also calculated. @*Results@#The Cronbach's alpha for work engagement was 0.776, indicating acceptable internal consistency. The model comprising 3 work engagement and 2 burnout items showed an excellent fit (χ2 : 382.05, Tucker-Lewis index: 0.984, comparative fit index: 0.994, root mean square error of approximation: 0.043). The convergent validity was significant (correlation coefficient: 0.42). Correlations with burnout and job demands were negligible, whereas correlations with job resources and job satisfaction were weakly positive. @*Conclusions@#The results of our study confirm that the WES-3 has acceptable reliability and validity.

Korean translation and validation of the Workplace Positive emotion, Engagement, Relationships, Meaning, and Accomplishment (PERMA)-Profiler

BACKGROUND: No tool is available for the multidimensional measurement of workplace well-being among Korean workers. In this study, the Workplace Positive emotion, Engagement, Relationships, Meaning, and Accomplishment (PERMA)-Profiler, a multidimensional workplace well-being measure, was translated into Korean, and its validity and reliability were assessed. METHODS: The Workplace PERMA-Profiler, including the positive emotion, engagement, relationships, meaning, and accomplishment domains, was translated according to international guidelines. The questionnaires included the Workplace PERMA-Profiler, Mental Health Continuum-Short Form, Utrecht Work Engagement Scale, Maslach Burnout Inventory-General Survey, Psychosocial Well-being Index-Short Form, and Korean Occupational Stress Scale-Short Form. A total of 316 Korean workers completed a web-based survey with adequate response. Cronbach's alpha values were calculated to assess scale reliability, and correlational and confirmatory factor analyses were used to assess validity. RESULTS: Cronbach's alpha values for the Korean Workplace PERMA-Profiler ranged from 0.70 to 0.95. Confirmatory factor analysis indicated that the 5-factor model had a marginally acceptable fit [χ²(80) = 383.04, comparative fit index = 0.909, Tucker-Lewis index = 0.881, root mean square error of approximation = 0.110, and standardized root mean square residual = 0.054]. The 5-factor PERMA domains were correlated positively with work engagement and mental well-being in life, and negatively with burnout, occupational stressors, and stress responses. These results showed that the Workplace PERMA-Profiler has good convergent and divergent validity. CONCLUSIONS: The Korean version of the Workplace PERMA-Profiler had good reliability and validity. It might be used as an indicator or evaluation tool for positive mental health interventions in the workplace.

Relationship between residence characteristics and polycyclic aromatic hydrocarbon exposure in housewives: second Korean National Environmental Health Survey (2012–2014)

BACKGROUND: Polycyclic aromatic hydrocarbons (PAHs) produced by incomplete combustion have negative effects on human health due to their carcinogenicity and teratogenicity. Indoor sources of PAHs include tobacco smoke, heating sources, and cooking. This study evaluated the relationship between human PAH exposure and residence characteristics. METHOD: This study was based on the second Korean National Environmental Health Survey (2012–2014). Non-smoking housewives were included in the analyses (n = 1269). The concentrations of urinary PAH metabolites (2-naphthol, 2-hydroxyfluorene, 1-hydroxyphenanthrene, and 1-hydroxypyrene) were adjusted by urine creatinine level. The geometric mean concentrations of urinary PAH metabolites by residential factors were examined. Logistic regression models were used to evaluate associations between residential variables and PAH exposures. RESULTS: The adjusted geometric mean concentrations of urinary 2-hydroxyfluorene and 1-hydroxyphenanthrene were significantly higher in the group residing within 100 m of a major road (p  100 m from a major road. In logistic regression analyses, the odds ratio (OR) for exceeding the third quartile of urinary 1-hydroxypyrene concentration was significantly higher in the group using coal or wood fuel for residential heating than in the group using gas (OR = 2.745, 95% confidence interval [CI] = 1.295–5.819). The detached house group had a significantly higher OR for 1-hydroxyphenanthrene compared with the apartment group (OR = 1.515, 95% CI = 1.023–2.243). CONCLUSION: Our study shows the evidence of associations between some urinary PAH metabolite levels (1-hydroxyphenanthrene and 1-hydroxypyrene) and residence characteristics. Additional studies are needed to clarify these associations.

The work–life balance and psychosocial well-being of South Korean workers

BACKGROUND: It is challenging to balance work and life, and little attention has been paid to the work–life balance and psychosocial well-being of South Koreans. We assessed the association between work–life balance and psychosocial well-being among paid Korean workers. METHODS: This study was based on data from the fourth Korean Working Conditions Survey. We evaluated only paid workers, which constituted 30,649 of the total of 50,007 subjects surveyed. Poor work–life balance was defined based on the goodness of fit between working hours and social commitments. Well-being was measured using the World Health Organization WHO-5 index. Poisson regression with robust variances was used to calculate the estimated prevalence ratios (PRs) with confidence intervals. RESULTS: Poor work–life balance was associated with poor psychosocial well-being (PR = 1.25; 95% CI 1.21 to 1.28) even after adjusting for work-related and individual characteristics. Poor well-being was associated with low-level job autonomy (PR = 1.06; 95% CI 1.03 to 1.09), working for ≥53 h per week (PR = 1.10; 95% CI 1.06 to 1.14), blue-collar status (PR = 1.16; 95% CI 1.11 to 1.21), low-level support at work (PR = 1.32; 95% CI 1.29 to 1.36), age ≥ 50 years (PR = 1.21; 95% CI 1.15 to 1.26), the female gender (95% CI PR = 1.04; 95% CI 1.01 to 1.07), and cohabitation (living with somebody) (PR = 1.08; 95% CI 1.04 to 1.12). Good well-being was associated with high-intensity work (PR = 0.96; 95% CI 0.94 to 0.99), being the secondary earner in a household (PR = 0.82; 95% CI 0.79 to 0.85), and higher income (PR = 0.75; 95% CI 0.71 to 0.79). CONCLUSION: Work–life balance was associated with psychosocial well-being after adjusting for both work-related and individual characteristics.

Perception of and attitude toward ethical issues among Korean occupational physicians

BACKGROUND: Occupational physicians (OPs) have complex relationships with employees, employers, and the general public. OPs may have simultaneous obligations towards third parties, which can lead to variable conflicts of interests. Among the various studies of ethical issues related to OPs, few have focused on the Korean OPs. The aim of the present survey was to investigate the ethical contexts, the practical resolutions, and the ethical principles for the Korean OPs. METHODS: An email with a self-administered questionnaire was sent to members of the Korean Society of Occupational and Environmental Medicine, comprising 150 specialists and 130 residents. The questionnaire was also distributed to 52 specialists and 46 residents who attended the annual meeting of the Korean Association of Occupational and Environmental Clinics in October 2015, and to 240 specialists by uploading the questionnaire to the online community ‘oem-doctors’ in February 2016. The responses to each question (perception of general ethical conflicts, recognition of various ethical codes for OPs, core professional values in ethics of occupational medicine, and a mock case study) were compared between specialists and residents by the chi-squared test and Fisher’s exact test. RESULTS: Responses were received from 80 specialists and 71 residents. Most participants had experienced ethical conflicts at work and felt the need for systematic education and training. OPs suffered the most ethical conflicts in decisions regarding occupational health examination and evaluation for work relatedness. Over 60% of total participants were unaware of the ethical codes of other countries. Participants thought ‘consideration of worker’s health and safety’ (26.0%) and ‘neutrality’ (24.7%) as the prominent ethical values in professionality ofoccupational medicine. In mock cases, participants chose beneficence and justice for fitness for work and confidential information acquired while on duty, and beneficence and respect for autonomy in pre-placement examinations. CONCLUSIONS: This study evaluated the current perception of and attitude toward ethical issues among the Korean OPs. These findings will facilitate the development of a code of ethics and the ethical decision-making program forthe Korean OPs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40557-017-0182-z) contains supplementary material, which is available to authorized users.

Effects of shift work on abdominal obesity among 20–39-year-old female nurses: a 5-year retrospective longitudinal study

BACKGROUND: This study aimed to investigate the effects of shift work on abdominal obesity among young and middle-aged female nurses during a 5-year retrospective study. METHODS: This retrospective study included female nurses (20–39 years old) who worked at a university hospital in Korea and had available health screening results from 2010–2015. Among 2,611 employees, 934 healthy 20–39-year-old female nurses were identified, and data regarding their demographic information (age and date of employment), waist circumferences (WC), and lifestyle factors (alcohol and exercise) were obtained. Abdominal obesity was defined as a WC of ≥80 cm, based on the World Health Organization’s Asia-West Pacific standard in 2000. The mean WC change from baseline was analyzed using the paired t test, and the association between shift work and abdominal obesity was analyzed using the generalized estimating equation. RESULTS: Compared to all day workers (both age groups), the 20–29-year-old nurses did not exhibit significant changes in WC at each follow-up. However, among the 30–39-year-old nurses, shift workers exhibited a significant change in WC (vs. baseline) during years 4 and 5, compared to day workers. After adjusting for effective confounders and stratifying the participants according to age, the 20–29-year-old nurses exhibited an odds ratio of 3.21 (95 % confidence interval: 1.29–7.98) for shift work-associated obesity, although the odds ratio for the 30–39-year-old nurses was not statistically significant. CONCLUSION: In the study population, shift work was associated with a significant change in mean WC among 30–39-year-old nurses, and the shift work-associated risk of abdominal obesity was significant among 20–29-year-old nurses. These results indicate that shift work may influence abdominal obesity differently in 20–29-year-old and 30–39-year-old female nurses.

Relationship between housing characteristics, lifestyle factors and phthalates exposure: the first Korean National Environmental Health Survey (2009-2011)

No abstract available.

The effect of applying ethnicity-specific spirometric reference equations to Asian migrant workers in Korea

OBJECTIVES: Asian migrant workers in Korea have various ethnicities. The purpose of this study was to evaluate the difference in spirometric interpretation made using the set of third National Health and Nutrition Examination Survey (NHANES III) reference equations and the relevant ethnicity-specific reference sets. METHODS: Spirometry was performed on 166 migrant and 498 Korean male workers between March and November 2012. We analyzed the spirometric data of healthy never-smokers. Spirometric patterns were evaluated using the NHANES III reference set and some relevant ethnicity-specific equations (Eom's equation for Koreans, Ip's equation for East Asians, Crapo's equation for Central Asians, Memon's equation for South Asians, and Gnanou's equation for Southeast Asian people). RESULTS: In all migrant groups except the Central Asian group, the forced expiratory volume in 1 second percentage (FEV1%) and forced vital capacity percentage (FVC%) calculated using each of the ethnicity-specific reference equations considered were significantly higher than those calculated using the NHANES III reference set. This study showed that in the evaluation of the spirometric result of subjects from Southeast Asia or South Asia, the percentage of cases with an abnormal FEV1 or FVC increased when the NHANES III set of equations was used as compared to when the ethnicity-specific equations were used. CONCLUSIONS: We found that the spirometric results of all ethnic groups were higher and the composition of the abnormal spirometric result was lower when the ethnicity-specific reference equations were used instead of the NHANES III reference set.

Decline in non-smoking workers' urine cotinine levels after increased smoking regulation in Korea

OBJECTIVES: To identify any association between implementing smoking regulation policies and workers' urine cotinine concentration levels in Korea. METHODS: From the first stage of the Korean National Environmental Health Survey conducted by the National Institute of Environmental Research from 2009 to 2011, 2,475 non-smoking workers selected. We analyzed the trend in the changes of cotinine concentration in urine using the general linear model and linear regression, in various jobs as categorized by the National Center for Health Statistics (NCHS) and Korea Standard Classification of Occupations (KSCO). RESULTS: The urine cotinine concentration tended to decrease every year (2.91 ng/ml in 2009, 2.12 ng/ml in 2010, and 1.31 ng/ml in 2011), showing a decreasing trend (P < 0.001). The total subjects' decreased cotinine concentration in urine between 2009 and 2011 was 2.72 ng/ml (54.1 % relative decrease). The changes in each subgroup's urine cotinine concentration ranged from 1.59 to 6.03 ng/ml (33.2 to 77.5 %). All groups except for the managerial group (n = 49), which had a small sample size, had statistically significant negative regression coefficients (p < 0.05). The ranges of the decrease in urine cotinine were 2.75 ng/ml (53.6 %) for males and 2.72 ng/ml (54.9 %) for females. The negative slope in urine cotinine level was statistically significantly greater in men than women. The changes in urine cotinine by occupation as classified by the NCHS occupational categories ranged from 2.43 to 3.36 ng/ml (46.6 to 61.5 % relative decrease). The negative slopes in urine cotinine levels of the white-collar and farm workers were statistically significantly greater than those of the service workers and blue-collar workers. The change by occupation as classified by the KSCO ranged from 1.59 to 6.03 ng/ml (a 33.2 to 77.5 % relative decrease). The negative slopes in urine cotinine levels of the professionals and related workers and clerks were statistically significantly greater than those of the service workers and plant and machine operators and assemblers. CONCLUSIONS: The cotinine concentration in urine among non-smoking worker groups tended to decline from 2009 to 2011. Such a result may be an indirect indicator of the effectiveness of smoking regulation policies including the revision of the National Health Promotion Act.

High lead exposure in two leaded bronze ingot foundry workers

BACKGROUND: Awareness about lead poisoning in South Korea has increased; however, occupational exposures occurring in small-scale businesses have not been thoroughly investigated. We report two cases of high lead exposure in a leaded bronze ingot foundry. CASE PRESENTATION: Two employees, a 54-year-old primary operator and a 46-year-old assistant, at a small-scale metalworking company who had been employed for 18 years and 1 month, respectively, showed elevated blood lead levels (61.1 mug/dL and 51.7 mug/dL, respectively) at an occupational health checkup. Neither worker complained of abnormal symptoms nor signs related to lead poisoning. Health assessment follow-ups were conducted and biological exposure indices of lead were calculated every four weeks. After the initial follow-up assessment, both workers were relocated from the foundry process to the metalworking process. In addition, a localized exhaust system was installed after the second follow-up. CONCLUSIONS: Foundry workers in a small-scale businesses might be at high risk of lead exposure because these businesses might be vulnerable to poor industrial hygiene. Therefore, regular occupational health checkups are required.

Effectiveness of a Comprehensive Stress Management Program to Reduce Work-Related Stress in a Medium-Sized Enterprise

OBJECTIVES: To assess the effectiveness of a comprehensive workplace stress management program consisting of participatory action-oriented training (PAOT) and individual management. METHODS: A comprehensive workplace stress management program was conducted in a medium-sized enterprise. The baseline survey was conducted in September 2011, using the Korean Occupational Stress Scale (KOSS) and Worker's Stress Response Inventory (WSRI). After implementing both organizational and individual level interventions, the follow up evaluation was conducted in November 2011. RESULTS: Most of the workers participated in the organizational level PAOT and made Team-based improvement plans. Based on the stress survey, 24 workers were interviewed by a researcher. After the organizational and individual level interventions, there was a reduction of several adverse psychosocial factors and stress responses. In the case of blue-collar workers, psychosocial factors such as the physical environment, job demands, organizational system, lack of rewards, and occupational climate were significantly improved; in the case of white-collar workers, the occupational climate was improved. CONCLUSIONS: In light of these results, we concluded that the comprehensive stress management program was effective in reducing work-related stress in a short-term period. A persistent long-term follow up is necessary to determine whether the observed effects are maintained over time. Both team-based improvement activities and individual interviews have to be sustainable and complementary to each other under the long-term plan.

A Case of Obstructive Sleep Apnea and Assessments of Fitness for Work

BACKGROUND: Obstructive sleep apnea is a common sleep disorder that can cause excessive daytime sleepiness and impairment of cognition. These symptoms may lead to the occurrence of occupational accidents in workers with obstructive sleep apnea. CASE PRESENTATION: A 36-year-old man who worked as a dimensional control surveyor caused a vehicle accident while he was driving at the work site. Although he experienced loss of consciousness at the time of the accident, he had no other symptoms. His brain computed tomography and laboratory test did not show any specific findings. Medical tests were conducted to evaluate his fitness for work. Decreased sleep latency was observed on the electroencephalography image, which is suggestive of a sleep disorder. He frequently experienced daytime sleepiness and his Epworth sleepiness score was 13. The polysomnography showed a markedly increased apnea-hypopnea index of 84.3, which led to a diagnosis of severe obstructive sleep apnea. The patient was advised to return to work only when his obstructive sleep apnea improved through proper treatment. CONCLUSION: Proper screening for obstructive sleep apnea among workers is important for preventing workplace accidents caused by this disorder, but screening guidelines have not yet been established in Korea. An effort toward preparing practical guidelines for obstructive sleep apnea is needed.

Second-hand Smoke Exposure and Urine Cotinine Levels by Occupation in the Busan, Ulsan, Kyeongnam Provinces / 대한산업의학회지

OBJECTIVES: Exposure to second-hand smoke varied by smoking rate in the workplace and no-smoking policies. The purpose of this study was to estimate the status of second-hand smoke exposure by occupation through urine cotinine analysis in Busan, Ulsan, and Kyeongnam provinces. METHODS: Data was obtained from the National Institute of Environmental Research of Korea as 'The 2008 Korea National Survey for Environmental Pollutants in Human Body'. We selected 629 non-smokers who lived in Busan, Ulsan and Gyeongnam provinces. General and occupational characteristics were gathered using a structured questionnaire. Urine cotinine concentrations were analyzed by a gas chromatograph-mass selective detector. Statistical analysis was carried out using the Chi-square test, Student t-test and ANOVA. RESULTS: The geometric mean (geometric standard deviation) of urine cotinine concentration was 17.11 (2.74) ng/ml. The urine cotinine concentration of the middle school graduate group (18.47 (2.86) ng/ml) was higher than the college graduate group (15.64 (2.60) ng/ml, p=0.212). Also, the cotinine concentration of current drinkers (18.98 (2.47) ng/ml) was higher than non-drinkers (16.15 (2.88) ng/ml, p=0.054). The proportion who smelled smoke was higher in workers (38.5%) than in non-workers (29.7%, p=0.02). Therefore, urine cotinine concentration was higher in workers (17.29 (2.66) ng/ml) than in non-workers (16.97 (2.81) ng/ml) but not at a statistically significant amount (p=0.826). In addition, cotinine concentration between the group who smelled smoke (20.45 (2.42) ng/ml) and the group who did not smelled smoke (15.53 (2.78) ng/ml) was significantly different (p=0.016) in workers but not in non-workers (17.08 (2.42) ng/ml vs 16.92 (2.98) ng/ml, p=0.942). According to the National Center for Health Statistics occupational categories in the US and the Korea Standard Classification of Occupations, the urine cotinine concentration of white collar workers such as technical workers and administrators, professional specialists, and managers was higher (18.01 (2.55) ng/ml) than that of blue collar workers such as plant and machine operators and assemblers, elementary occupations, and craft and related trades workers (15.36 (3.48) ng/ml). CONCLUSIONS: The workplace is an important contributor to second-hand smoke exposure in Busan, Ulsan and Kyeongnam provinces. Unlike in advanced countries, where anti-smoking policies have been implemented, urine cotinine concentration in people in Busan, Ulsan and Kyeongnam provinces was higher in the white collar group than in the blue collar group. This result might be due to a higher indoor second-hand smoking rate of workplaces in these areas. Further studies are needed to evaluate the correlation between regional characteristics of industries, anti-smoking policies in the workplace, smoking rates and urine cotinine concentrations of workers.

Cognition and Practice on Medical Information Protection of Iudustrial Health Care Manager of Small and Medium Sized Enterprises / 대한산업의학회지

OBJECTIVES: This research aimed to know the actual condition and problems of medical information protection at a workplace with the target of industrial health care managers of small and medium-sized enterprises. METHODS: A self-administered questionnaire was given to industrial health-care managers of 216 enterprises from March 15 to May 17, 2010. The questionnaire was produced by referring to the Act on Personal Information Protection of Public Institutions, etc. This research evaluated agreement of cognition and practice according to 10 items of medical information protection using kappa and cross-analysis of significant factors between cognition and practice of medical information protection and general characteristics. RESULTS: Cognition about medical information protection appeared to be 85.4-97.1% and its practice appeared to be 44.1-95.3%, so practice was lower than cognition. In addition, the agreement of cognition and practice appeared significantly low (kappa 0.082-0.387). The practice of medical information protection tended to be lower when the managers were older and held a higher job title. Health examination results were being delivered only to workers except for an employer (94.2%), but there were many industrial health-care managers who felt discomfort about their work in group occupational health-care systems (58.1%). CONCLUSIONS: The practice of protecting medical information by industrial health-care managers was clearly lower than the cognition. Therefore, introduction of educational programs about personal information protection and provision of an independent place for group occupational health care service is urgent. In addition, in order to use the health examination results conveniently in group occupational health services, an institutional complement is necessary.

Medical Professionalism of Occupational and Environmental Physicians in Korea / 대한산업의학회지

OBJECTIVES: This study evaluated cognition, core values and attributes of medical professionalism in occupational and environmental physicians, and was conducted to have basic data for suggesting proper role models of occupational and environmental physicians. METHODS: Perceptions of reality and the priority of professionalism virtues in occupational and environmental medicine were evaluated by using a self-administered questionnaire, completed by 109 occupational and environmental physicians in Korea. The physicians were divided into two sub-groups: the resident group and the board certified specialist group. There are 4 questions about perceptions of reality and survey respondents gave 5-scale scores to each of 10 professionalism virtues in the questionnaire. The statistical significance of the perception difference between two groups was given by a cross tabulation analysis. Priority difference between each 10 professionalism virtue between the two groups was analyzed through Student T-test by using the SPSS 17.0K program. Afterwards, the type of medical professionalism in occupational and environmental medicine was analyzed based on the results of the questionnaire. RESULTS: This study provided us with the information that specialists had more optimistic views about reality of occupational and environmental medicine than residents. 10 virtues of medical professionalism were listed in the order of priority, highest to lowest. Occupational and environmental physicians valued 'technical competence', 'professional dominance', and 'morality', but 'altruism' had the lowest score. CONCLUSIONS: This study demonstrated that the occupational and environmental physicians's type of medical professionalism didn't match any of the seven types of medical professionalism from Castellani & Hafferty, although 'empirical type', 'nostalgic type' were partially similar to the occupational and environmental physician's type of medical professionalism. This is assumed because the occupational and environmental medicine field is different from other clinical medicine in terms of the physician's role. Further studies and discussions are necessary for establishing a suitable model of medical professionalism for occupational and environmental physicians.

Lifestyle and Work related Factors Associated with Serum PFOA among Workers at Manufacturing Companies / 대한산업의학회지

OBJECTIVES: The objective of this study was to determine serum perfluorooctanoic acid (PFOA) concentrations and to investigate the relationship of lifestyle, health status and work-related factors among workers at manufacturing companies with possible occupational exposure to PFOA. METHODS: The study subjects were 315 workers (male 203, female 112) of manufacturing companies with possible exposure to PFOA from August to December, 2007. A questionnaire was administered to investigate lifestyle and work-related factors. Serum PFOA concentrations were analyzed by LCMS/ MS, and liver function and total cholesterol were also tested. RESULTS: Serum PFOA concentrations ranged from 1.0 to 40.9 ng/mL (mean 8.0 ng/mL). Serum PFOA concentrations increased with age. Male workers had higher PFOA concentration than female workers (male 9.0 ng/mL; female 6.3 ng/mL). According to stepwise multiple regression analysis, factors significantly associated with PFOA concentration were male, being older, higher total cholesterol, and lower body mass index. Adjusted for age and gender by logistic regression, dyeing and finishing textiles had significantly higher odds ratio (OR) of 6.16, and moulding patterns, moulds and industrial patterns (OR=4.84), sections for ships (OR=3.87), and plastics synthetic leather (OR=10.05) had marginally significantly high odds ratios. CONCLUSIONS: This study demonstrated the factors affecting serum PFOA concentration of workers at manufacturing companies. Further study is needed to ensure the effect of occupational exposure on serum PFOA concentration.

Pulmonary Function and Respiratory Symptoms of Municipal Fire Officers in Busan / 대한산업의학회지

OBJECTIVES: The purpose of this study was to evaluate the relationship between respiratory disorders and fire exposure by investigating and analyzing the lung function and respiratory symptoms of firefighters. METHODS: The health effects of firefighting on respiratory function were investigated in 699 male fire officers in 4 fire departments in Busan by recording respiratory symptoms and measuring lung function. The data were analysed according to fire exposure and smoking habits. RESULTS: Mean spirometric data showed significantly decreased levels in the fire-exposed group (FVC, -0.20 L; FVC%, -4.2%; FEV(1) -0.21 L; FEV(1)%, -5.1%; FEF25%, -0.13 L/SEE p<0.05). After stratification by smoking habits, FVC and FEV(1) showed a significant difference between groups. The prevalence of spirometric abnormality was greater for the fire-exposed group than for the non-exposed group. Significantly higher prevalences of nasal stiffness (16.7% vs. 10.9%), sore throat (17.7% vs.14.2%) and chest tightness (6.5% vs. 2.5%) were recorded in firefighters compared to controls (p<0.05). However, after stratification by smoking habits, the 3 symptoms were showed only marginal differences in the smoking group. CONCLUSIONS: This study demonstrated that fire-exposed firefighters generally suffer a decline of lung function and a higher prevalence of respiratory symptoms. These results suggest that the exposure to routine firefighting activity is associated with adverse health effects to the respiratory system.

Gene Expression Analysis in Basal Ganglia of Manganese-Exposed Rat Based on cDNA Array / 대한산업의학회지

OBJECTIVES: This study investigated the gene expression profile in basal ganglia of manganese-exposed rats based on cDNA array analysis. METHODS: For cDNA array, 25 male Sprague-Dawley rats (250+/-25 g) were intraperitoneally injected with 25 mg/kg B.W./day of MnCl2 (0.3 ml) for 10 days. For dose-related gene expression analysis, rats were intraperitoneally injected with 0.2, 1.0, and 5.0 mg/kg B.W/day of MnCl2 for 10 days. Control rats were injected with an equal volume of saline. RNA samples were extracted from brain tissue and reversetranscribed in the presence of [alpha32P]-dATP. Membrane sets of the Atlas Rat 1.2 array II and Toxicology array 1.2 kit (Clontech, Palo Alto, CA) were hybridized with cDNA probe sets. Northern blot hybridization method was employed to assess the dose-related gene expression. RESULTS: Fifty-two genes showed significant changes in expression of more than two-fold. Twentyeight were up-regulated and 24 were down-regulated in the manganese-exposed group compared to the control. Among the 52 genes, 28 genes including nuclear factor I-X1 (NF1-X1), neuroligin 2 and 3, mitochondrial stress-70 protein (MTHSP70), neurodegeneration-associated protein 1 (Neurodap1), multidrug resistance protein (MDR), and endoplasmic reticulum stress protein 72 (ERP72), were reported for the first time related to the manganese-induced neurotoxic-metabolism in the rat basal ganglia. According to the dose-related gene expression analyses, MTHSP70, Neurodap1 and ERP72 genes were up-regulated compared to the control even in the group exposed to low manganese dose (0.2 mg/kg B.W./day). CONCLUSIONS: Twenty-eight genes detected for the first time in this study were closely related to the manganese-induced neurotoxic-metabolism in the rat basal ganglia and further study of these genes can give some more useful information about the manganese metabolism.

Effects of Cadmium on Placental Function and Reproduction in Rats / 대한산업의학회지

OBJECTIVES: This study investigated the toxic effects of cadmium on placental function and reproduction in rats. For this study, the mRNA levels of the placental prolactin-growth hormone (PRL-GH) gene family, placental trophoblast cell frequemcy and reproductive data were analyzed. METHODS: Pregnant F344 Fisher rats (200 g+/-23 g) were intraperitoneally injected with 0, 0.5, and 5.0 mg/kg B.W/day of cadmium (CdCl2) dissolved in saline from days 7-11 or 16-20 of pregnancy, and were sacrificed at days 11 or 20, respectively. The mRNA levels were analyzed by Northern blot hybridization and reverse transcription-polymerase chain reaction. The hormone concentration was analyzed by radioimmunoassay and the frequemcy of the placental trophoblast cells was observed by histochemical study. Reproductive data were surveyed at day 20 of the pregnancy and after the births. Statistical analysis was carried out using the SAS program (version 8.1). RESULTS: The mRNA levels of the PRL-GH gene family were reduced dose dependently by cadmium. The mRNA levels of Pit-1a and -b isotype genes were also reduced by cadmium. The hormone concentration of PL-Iv and -II was decreased by cadmium. During the second half of pregnancy (days 11-21), a high dose of cadmium exposure significantly reduced the frequency of spongiotrophoblast and trophoblast giant cells that secrete the PRL-GH hormones. In the last stage of pregnancy (day 20), a high dose of cadmium exposure induced the apoptosis of spon-giotrophoblast cells in the junctional zone of the placenta. Reproductive data such as placental and infant weight, number of live fetuses were decreased, and number of resorptions and dead fetuses, post-implantation loss were increased significantly in the cadmium exposed group compared with the control. CONCLUSIONS: Cadmium disrupts the functions of the placenta and these effects leads to reproductive disorders in rats.