Validity of Breast Cancer Symptom Questionnaire and Its Relationship With Breast Ultrasonography in Young Female Night Workers

Background@#This study aimed to identify the validity of breast cancer symptom questionnaire of worker's special health examination and its relationship with breast ultrasonography findings in young female night workers. @*Methods@#The breast cancer symptom questionnaire data of worker's special health examination and breast ultrasonography results in young female shift workers who worked in one electronic manufacture company were collected from 2014 to 2018. @*Results@#Of the 857 workers, 18 had a Breast Imaging Reporting and Database System category 4 or higher. Among other variables, shift work tenure alone was associated with the risk of having a Breast Imaging Reporting and Database System category higher than 4. The sensitivity, specificity, positive predictive value, and negative predictive value of the symptom questionnaire were 16.7%, 87.7%, 2.8%, and 98.0%, respectively. @*Conclusion@#The current breast cancer symptom questionnaire of the worker's special health examination is inappropriate due to its low sensitivity and positive predictive value. In the future, female night workers will need alternative measures for more accurate screening for breast cancer.

Comparison of risk-assessment tools for cardio-cerebrovascular diseases (CVD) in male shipyard workers: a cross-sectional study

BACKGROUND: Periodic revision of assessment tools is essential to ensure risk assessment reliability and validity. Despite the recent revision of the Korea Occupational Safety and Health Agency (KOSHA) 2018, there is no evidence showing that the revision is superior to other cardio-cerebrovascular diseases (CVDs) risk-assessment tools for workplace health management. We conducted a comparative analysis using the Framingham risk score (FRS) as a gold standard to identify the most relevant CVDs risk-assessment tool for workplace health management. METHODS: We included 4,460 shipyard workers who had undergone a workers' health examination during January–December 2016. Risk levels for CVDs were calculated based on the FRS, KOSHA 2013, KOSHA 2017, KOSHA 2018 (2 methods), National Health Screening Program health risk appraisal (NHS HRA) 2017, and NHS HRA 2018. Study participants were categorized into low-risk, moderate-risk, or high-risk groups. Sensitivity, specificity, correlation, and agreement of each risk-assessment tool were calculated compared with the FRS as a gold standard. For statistical analyses, Spearman's rank correlation coefficient and the linearly weighted kappa coefficient were calculated. RESULTS: Sensitivity of the risk assessments was highest in the KOSHA 2018 (health risk appraisal [HRA]). The FRS showed correlation coefficients of 0.354 with the KOSHA 2013, 0.396 with the KOSHA 2017, 0.386 with the KOSHA 2018, 0.505 with the KOSHA 2018 (HRA), 0.288 with the NHS HRA 2017, and 0.622 with the NHS HRA 2018. Kappa values, calculated to examine the agreement in relation to the KOSHA 2013, KOSHA 2017, KOSHA 2018, KOSHA 2018 (HRA), NHS HRA 2017, and NHS HRA 2018 with the FRS, were 0.268, 0.322, 0.352, 0.136, 0.221, and 0.559, respectively. CONCLUSIONS: The NHS HRA 2018 risk calculation method is a useful risk-assessment tool for CVDs, but only when appropriate classification criteria are applied. In order to enhance the risk-group identification capability of the KOSHA guideline, we propose to apply the classification criteria set in this study based on the risk group definition of the 2018 Korean Society of Hypertension guidelines for the management of hypertension instead of the current classification criteria of the KOSHA 2018.

The effect of shift work on high sensitivity C-reactive protein level among female workers

BACKGROUND: This study assessed the association between shift work and high-sensitivity C-reactive protein (hs-CRP) level, a risk factor for cardiovascular disease (CVD), in female workers in electronics manufacturing services (EMS). METHODS: Female EMS workers who received special medical examinations for workers in Gyeongnam, Korea between January 2017 and December 2017 were enrolled in this study. Their age, marital status, education level, alcohol consumption, smoking habit, regular exercise, quality of sleep, work stress, and depression were investigated, and blood tests were conducted. The t- and χ2 tests were conducted to compare the general and biochemical characteristics between daytime and shift worker groups. Age-adjusted partial correlation analysis was performed to examine the linear relationship between hs-CRP level and other risk factors for CVDs. In addition, the difference in hs-CRP levels according to work schedule was analyzed by ANCOVA after adjusting for variables that could affect the hs-CRP level. RESULTS: Although the average hs-CRP levels did not differ significantly between daytime and shift workers (0.92 ± 1.87 and 1.07 ± 2.20 mg/dL, respectively), shift workers tended to show a higher hs-CRP level (p = 0.067). After adjusting for variables that can affect the hs-CRP level, the estimated average hs-CRP level was significantly higher in shift workers (1.325 ± 0.156 mg/dL) than that in daytime workers (0.652 ± 0.350 mg/dL) (p = 0.003). CONCLUSIONS: The results of this study identified a relationship between shift work and hs-CRP level increase in women. Because multiple studies have reported associations between increased hs-CRP and CVD, follow-up of hs-CRP may help early detection of CVD in shift workers.

Changes of depression and job stress in workers after merger without downsizing

BACKGROUND: Since the 1980s, restructuring, which includes downsizing, closures, mergers, and privatization, has expanded worldwide, and various studies have investigated its effect on health. However, previous studies have mainly focused on restructuring accompanied by massive lay-offs, and the effect of a merger on workers’ health is still controversial. This study aims to investigate changes in worker depression and job stress after a merger without downsizing, which is unusual in Korea. METHODS: Repeated surveys were done in April 2014, April 2015, and April 2016 involving the participation of 209 subjects. Participants were divided into two groups, which were comprised of blue-collar workers (104) and white-collar workers (105). Sociodemographic characteristics, including age, education level, job tenure, gender, marital status, smoking status, and alcohol consumption, were measured via a survey. To determine the level of depression, the Korean version of the Center for Epidemiologic Studies Depression Scale (CES-D) was employed, and to investigate job stress, the Korean Occupational Stress Scale-Short Form (KOSS-SF) was used. For statistical analyses, Pearson’s chi-square test, the Student’s t-test, and repeated measure analysis of variance (ANOVA) were performed. RESULTS: The results showed that depression (CES-D, F[2, 400] = 0.466, p = 0.628) was changed but without significance and job stress (KOSS-SF, F[1.899, 379.831] = 3.192, p = 0.045) were significantly different. The between-group difference in the CES-D score between the blue- and white-collar workers by survey administration time was not statistically significant (F = 0.316, p = 0.574). The interaction between the survey time and occupational group was also not statistically significant (F = 0.967, p = 0.381). The between-group difference in the KOSS-SF total score was not statistically significant (F = 1.132, p = 0.289), and the interaction between the survey administration time and occupational group was also not significant (F = 0.817, p = 0.437). In the job stress subgroup analyses Job insecurity and Lack of reward showed a significant difference by survey administration time. CONCLUSION: This study showed that a merger without massive downsizing can cause negative health effects such as an changes in depression and increase in job stress. To improve the health of workers, both the immediate negative effects on health, and the long-term effects or their resolution over time should be considered prior to the merger.

The relationship between serum vitamin D levels and sleep quality in fixed day indoor field workers in the electronics manufacturing industry in Korea

BACKGROUND: Although recent studies have investigated the influence of vitamin D on sleep patterns, there is a lack of research on the relationship between vitamin D and sleep patterns in Korean workers. This study focused on the relationship between serum vitamin D levels and sleep in fixed day indoor field workers in the electronics manufacturing industry in Korea. METHODS: The 1472 subjects who were included in this study were selected from fixed day workers in the electronics manufacturing industry who had received a worker’s special health examination at a hospital in Changwon, South Gyeongsang Province between January 2015 and December 2015. Nighttime workers and those who showed symptoms of depression were excluded from this study. The sociodemographic and lifestyle variables of the participants were investigated, including age, sex, marital status, level of education, body mass index, smoking habits, alcohol consumption habits, and regular exercise. Work-related factors were evaluated, such as employee tenure and occupational stress. Serum 25-hydroxyvitamin D was measured as an indicator of vitamin D levels, and quality of sleep was evaluated using the Pittsburgh Sleep Quality Index (PSQI) translated into Korean. RESULTS: The subjects had a mean serum vitamin D level of 13.70 ± 5.93 ng/mL. Vitamin D deficiency, defined as a serum vitamin D level of <10 ng/mL, was found in 24.8% of males and significantly more frequently in females (47.6%). Poor sleep quality was reported by 19.8% of participants with serum vitamin D levels ≥10 ng/mL and by 21.7% of those with serum vitamin D levels <10 ng/mL, which was a significant difference (P = .007). Multiple logistic regression analysis adjusting for significant variables found that poor sleep quality was more likely in those with vitamin D deficiency than those with higher serum vitamin D levels (odds ratio = 1.36; 95% CI, 1.01–1.82). A comparison of serum vitamin D levels and PSQI components showed that the mean scores for subjective sleep quality, sleep latency, and sleep duration were significantly higher in the vitamin D-deficient participants, indicating that the vitamin D-deficient participants had poorer sleep quality. CONCLUSIONS: This study investigated serum vitamin D levels in fixed day indoor field workers in the manufacturing industry in Korea and analyzed the relationship of vitamin D deficiency with sleep quality. A significant correlation was found between serum vitamin D deficiency and poor sleep quality. Based on the results of this study, sleep disorder management for workers can be improved by providing regular examinations checking their serum vitamin D levels and supplying vitamin D to workers with serum vitamin D deficiency to enhance their quality of sleep.

Erratum to: The relationship between quality of sleep and night shift rotation interval

There was an error in one of the author names in this article. The publisher apologises for any inconvenience caused.

The relationship between quality of sleep and night shift rotation interval

BACKGROUND: Shift work is closely related with workers' health. In particular, sleep is thought to be affected by shift work. In addition, shift work has been reported to be associated with the type or direction of shift rotation, number of consecutive night shifts, and number of off-duty days. We aimed to analyze the association between the night shift rotation interval and the quality of sleep reported by Korean female shift workers. METHODS: In total, 2,818 female shift workers from the manufacturing industry who received an employee physical examination at a single university hospital from January to August in 2014 were included. Subjects were classified into three groups (A, B, and C) by their night shift rotation interval. The quality of sleep was measured using the Korean version of the Pittsburgh Sleep Quality Index (PSQI). Descriptive analysis, univariate logistic regression, and multivariate logistic regression were performed. RESULTS: With group A as the reference, the odds ratio (OR) for having a seriously low quality of sleep was 1.456 (95% CI 1.171-1.811) and 2.348 (95% CI 1.852-2.977) for groups B and C, respectively. Thus, group C with the shortest night shift rotation interval was most likely to have a low quality of sleep. After adjustment for age, obesity, smoking status, alcohol consumption, exercise, being allowed to sleep during night shifts, work experience, and shift work experience, groups B and C had ORs of 1.419 (95% CI 1.134-1.777) and 2.238 (95% CI 1.737-2.882), respectively, compared to group A. CONCLUSION: Our data suggest that a shorter night shift rotation interval does not provide enough recovery time to adjust the circadian rhythm, resulting in a low quality of sleep. Because shift work is influenced by many different factors, future studies should aim to determine the most optimal shift work model and collect accurate, prospective data.

Anxiety symptoms and occupational stress among young Korean female manufacturing workers

BACKGROUND: The prevalence of anxiety disorders has been increasing in South Korea, with recent studies reporting anxiety disorders as the most common mental disorder among all South Korean females. Anxiety disorders, which are independent risk factors of suicidal ideation and suicide attempts, are significantly correlated with productivity loss, high medical costs, impaired work performance, and frequent worker absence, and thus are potentially serious problems affecting the health of South Korean female workers. In previous studies, anxiety disorders were shown to have a significant correlation with occupational stress. This study seeks to examine the prevalence of anxiety symptoms as well as the relationship between occupational stress and anxiety symptoms among South Korean female manufacturing workers. METHODS: A structured self-reported questionnaire was administered to 1,141 female workers at an electrical appliance manufacturing plant. The questionnaire collected data on general characteristics, health behaviors, sleep quality, job characteristics (shift work, shift work schedule, and job tenure), occupational stress, and anxiety symptoms. Sleep quality was measured using the Pittsburgh Sleep Quality Index, occupational stress with the Korean Occupational Stress Scale-Short Form (KOSS-SF), and anxiety symptoms with the Korean version of the Beck Anxiety Inventory. A chi square test was conducted to determine the distribution differences in anxiety symptoms based on general characteristics, health behaviors, job characteristics, and sleep quality. A linear-by-linear association test was used to determine the distribution differences between anxietysymptoms and the levels of occupational stress. Last, logistic regression analysis was used in order to determine the association between occupational stress and anxiety symptoms. RESULTS: The prevalence of anxiety symptoms was 15.2 %. In the multivariate logistic regression analysis that adjusted for sleep quality and general characteristics, a significantassociation was found for those with anxiety disorders; the odds ratios (OR) were significantly higher the greater the total KOSS-SF score (moderate-risk group OR=2.85, 95 % CI=1.79-4.56; high-risk group OR=5.34, 95 % CI=3.59-7.96). In addition, excluding insufficient job control, all other KOSS-SF subscales were significantly associated with anxiety symptoms, and a relatively high OR was seen in the high-risk group for job demand (OR=3.19, 95 % CI=2.27-4.49), job insecurity (OR=4.52, 95 % CI=2.86-7.13), and occupational culture (OR=4.52, 95 % CI=2.90-7.04). CONCLUSION: There was a significant association between anxiety symptoms and occupational stress stemming from the psychosocial work environment among these South Korean female manufacturing workers. Future longitudinal studies are needed to examine the association between the occupational stress caused by the psychosocial work environment and the incidence of anxiety disorders and anxiety symptoms. Furthermore, intervention programs that aim to address the prevalence of anxiety symptoms and improve the psychosocial work environment, especially for younger female manufacturing workers, are needed.

Association between serum vitamin D and depressive symptoms among female workers in the manufacturing industry

BACKGROUND: Vitamin D has been known to maintain the body's balance of calcium and phosphorus as well as skeletal health. There has been increasing emphasis on the importance of vitamin D as recent studies have been reporting the specific functions of vitamin D in the cerebral nervous system and the association between the level of serum vitamin D and depressive symptoms. However, there is currently a paucity of research investigating the association between serum vitamin D and depressive symptoms in Korean subjects. Consequently, this study has aimed to determine the level of serum vitamin D and explore the association between serum vitamin D and depressive symptoms in Korean female workers. METHOD: A medical examination, questionnaire, anthropometric measurements, and a blood test were conducted between February 3 and March 7, 2014 in 1054 subjects among female workers in the manufacturing industry who underwent physical examinations in a university hospital. From this data, we identified the level of serum vitamin D and investigated the association between serum vitamin D deficiency and depressive symptoms. RESULTS: The average serum vitamin D level of the 1054 subjects was 9.07 +/- 3.25 ng/mL, and the number of subjects in the serum vitamin D deficiency group with less than 10 ng/mL was 721 (68.4 %). The odds ratio of the depressive symptom group with a CES-D score of 16 or above being in the deficiency group with a serum vitamin D level less than 10 ng/mL was found to be 1.55 (95 % CI = 1.15-2.07). CONCLUSION: 68.4 % of female workers in the manufacturing industry were in the deficiency group with serum vitamin D levels less than 10 ng/mL. Additionally, we identified an association between serum vitamin D deficiency and depressive symptoms. In the future, if serum vitamin D deficiency is checked regularly in workers, we expect to achieve better outcomes in managing their depressive symptoms.

The Relationship between Coronary Risk Factors and Coronary Calcium Score Detected by Computed Tomography Coronary Angiography in Korean Middle Aged Men / 農村醫學 地域保健

OBJECTIVES: The objective of this study was to investigate the relationship between coronary artery calcification and risk factors of cardiovascular disease with multidetector computed tomography. METHODS: Data were collected from 5,899 males between 30 and 59 years old by interview, survey, physical examination, blood test, and multidetector computed tomography in the university hospital from January 2010 to December 2011. We confirmed the coronary artery calcium scores of subjects by multidetector computed tomography and identified risk factors of cardiovascular disorders. We investigated the relationship between coronary artery calcification and risk factors of cardiovascular disorders. RESULTS: Mean calcium score of the coronary arteries in 5,899 participants was 8.20, and 773 participants (13.1%) exhibited coronary artery calcification. The presence of coronary artery calcification was correlated to risk factors of cardiovascular disease (age, blood pressure, triglyceride, HDL cholesterol, LDL cholesterol, glucose, Apolipoprotein A-1, Apolipoprotein B, body mass index, waist circumference) and risk assessment tools of cardiovascular disorders. Significant predicted factors of coronary artery calcification had different patterns in each age group (30-39, 40-49, 50-59 years old). CONCLUSIONS: We confirmed the relationship between coronary artery calcification and either typical risk factors of cardiovascular disease or risk assessment tools of cardiovascular disease. In addition, we also observed that the pattern of these factors varied according to age. Therefore, age-related variation needs to be considered in management strategies to prevent cardiovascular disease.

The Relationship between Fish Consumption and Blood Mercury Levels in Residents of Busan Metropolitan City and Gyeongnam Province / 農村醫學 地域保健

OBJECTIVES: The objective of this study was to identify the relationship between fish consumption and blood mercury levels in a sample of adult Koreans. METHODS: The study subjects were 299 residents of Busan (male: 65, female: 234) and 185 residents of Namhae (male: 69, female: 116), South Korea. Demographic characteristics, current smoking, current drinking, fish consumption per week, past history of amalgam treatment, and residential district were recorded by trained interviewers in June and July, 2009. We considered a portion of fish to be equivalent to 70 gm weight, and calculated amounts of fish consumed per week. Using chi-square tests, t-tests, ANOVA, and multiple linear regression analysis, we estimated the relationships between blood mercury levels and amount of fish consumed per week and other factors. RESULTS: The mean blood mercury level of our subjects was 6.61 microgram/L, higher than the criterion defined by the United States Environmental Protection Agency (EPA) (5.8 microgram/L). In multiple linear regression analysis, residential district and amount of fish consumed per week were associated with blood mercury levels. However, marital status, current drinking, and gender, and age were not associated with blood mercury levels. CONCLUSIONS: In conclusion, we suggest the implementation of systematic and periodic population-based studies to decrease the risks of mercury poisoning among South Koreans who consume fish as a regular part of the diet.

The Relationship of Serum Vitamin D Levels and the Framingham Risk Score among Male Workers in the Manufacturing Sector / 대한산업의학회지

OBJECTIVES: A growing body of evidence states that vitamin D deficiencies may adversely affect cardiovascular disease, however data from Korean workers are lacking. The purpose of this study was to investigate the vitamin D level of the Korean worker and the relationship between vitamin D levels and the Framingham Risk Score. METHODS: 11,448 male workers who visited a university hospital for health screening between March 2010 and August 2011, were enrolled in the study. We measured their of serum vitamin D(25(OH)D) levels and calculated their Framingham Risk Score. RESULTS: The mean serum vitamin D(25(OH)D) level of the surveyed workers was 13.03+/-6.47 ng/mL. 12.4% of the total workers had adequate vitamin D levels. It was found that the lower the vitamin D level, the higher the risk of cardiovascular disease. The Framingham Risk Score and vitamin D levels were found to be significantly related (OR=1.39, 95% CI 1.14~1.68) through a multivariate logistic regression analysis. CONCLUSIONS: 87.6% of workers possessed inappropriate vitamin D levels. Management for this high risk group in regards to cardiovascular disease should be included in the evaluation and vitamin D levels should be corrected.

Sex Differences in Lifestyle Factors of Metabolic Syndrome in Korean Adults

BACKGROUND: Metabolic syndrome is a major risk factor for cardiovascular disease. The combination of an aging population with a chronic diseased population is leading to an increase in the mortality rate due to cardiovascular diseases. The purpose of this study was to assess the prevalence of metabolic syndrome in the Korean population and to evaluate its related factors for sex differences. METHODS: From April 2007 to December 2008, a total of 2,729 volunteers aged 40-69 years living in Changwon city underwent a clinical examination at a hospital in Changwon, Korea. Metabolic syndrome was diagnosed following the criteria defined in Circulation 2009. The clinical examination included measuring anthropometric variables and cardiovascular risk factors, while lifestyle factors were assessed through a questionnaire. RESULTS: The prevalence of metabolic syndrome in our sampling pool was 25.2% with a break down by sex showing a rate of 30.2% in men and 22.2% in women. Related factors associated with metabolic syndrome common to both sex were age, self-health assessment, and alcohol consumption. Sleep duration seemed to be a related factor in men, while income, education, and menstruation status played significant roles in women. CONCLUSIONS: To better manage metabolic syndrome, men need to be educated on alcohol use and women of low socioeconomic status require particular attention as do the aging population and postmenopausal women.

A Study of the Results of Sputum Cytology as a Special Health Examination / 대한산업의학회지

OBJECTIVES: This study aims investigate the results of sputum cytology, which began its test period from 2009 as a special health examination for individuals whose lungs have been exposed to carcinogens. METHODS: 22,215 cases of sputum results were classified into six categories through Papanicolau classification. The sputum results were analyzed according to age, exposure degree to welding fumes and smoking status. Chi-square tests and logistic regression analysis were used to compare and analyze the associations between sputum results and smoking status, exposure degree and age classifications. RESULTS: The number of class I cases was 20,784 with a frequency of (93.6%), class II had 1,076 cases (4.8%), class III had 69 cases (0.3%), and the inadequate class had 286 cases (1.3%) and there were no cases in class VI and V. Patients in class III received CT scans of their chest for further evaluation, but no cancer patients were found from that. There were 2.48 times (95% CI 1.12~5.53) more smokers than non-smokers in class III and 1.70 times (95% CI 1.43~2.02) more in class II. The number of ex-smokers was 2.46 times (95% CI 1.01~5.99) larger than the number of non-smokers in class III and 1.28 times (95% CI 1.03~1.60) larger than the number of non-smokers in class II. There were 1.54 times (95% CI 1.28~1.85) more patients from the mid-exposure group than the low exposure group in class II. There were 1.62 times (95% CI 1.31~1.99) more patients from the high-exposure group than the low-exposure group in class II. CONCLUSIONS: As a screening test for lung cancer, the usefulness of sputum cytology is limited. However, the precancerous cells (class II, class III) varied according to welding fume exposure degree and smoking status.

A Case of Lead Poisoning by Ingesting Herbal Pills Tainted by Lead during the Manufacturing Process / 대한산업의학회지

BACKGROUND: This is a case report of lead poisoning after herbal pill ingestion. We report this case here as a reminder that contamination during the manufacturing process is an important issue regarding herbal pills. Case Report: A 37-year-old male was admitted to the hospital with abdominal pain caused by cholecystitis. He was transferred to the Department of Occupational and Environmental Medicine on 26 December 2008, because of anemia. On follow-up examination post cholecystectomy, the patient had increasing blood lead levels. There was no specific finding in his medical history, but he had been taking herbal pills for 3 months to treat dyspepsia. We performed an analysis on the herbal pills, and determined a lead concentration of 1485 mg/kg. When he was admitted to the hospital, the patient had a blood lead level of 84.13 microgram/dL and a zinc protoporphyrin level was 230 microgram/dL. The patient was treated with 250 mg of Penicillamine, 4 times per day. During follow-up 3 weeks later, the patient's blood lead level had been reduced to 36.52 microgram/dL which allowed us to take him off of Penicillamine. By 7 months follow-up, the patient's blood lead concentration had fallen from 36.52 microgram/dL to 20.93 microgram/dL. CONCLUSION: Lead poisoning was confirmed by analyzing blood lead levels and the cause was herbal pills. Upon analysis of the herbal pills, we have discovered that the herbal pills contained an amount of lead acquired during the manufacturing process, based on the high levels of this heavy metal in comparison to other metals. Private herbal pill manufacturing plants need systematic management and oversight.

The Effects of the Frequency of Fish Consumption on the Blood Mercury Levels in Koreans / 대한산업의학회지

OBJECTIVE: We studied two districts in Korea in order to investigate if the frequency of fish consumption has an effect on the blood mercury levels. METHODS: This survey was conducted on 164 fishing district residents in Geoje city and 219 agricultural district residents in Changwon city from July to August in 2008. The data on the demographic characteristics, the living environment, lifestyle habits and the frequency of fish consumption was collected by interviewers. We used ANOVA to estimate the particular relevance between the frequency of fish consumption and the blood mercury concentration, and other various factors. RESULTS: The mean total blood mercury level was 6.54+/-4.01 microgram/L for the total study population. Our results were even higher than that of the National Health and Nutrition Examination Survey (USA) in, 2001~2002 and the German Environmental Survey in, 1998. In this study, there was a significant difference for the frequency of eating fish between the groups. (p<0.01, The level of the groups that ate fish 3 to 4 times per week was significantly higher as compared with the level of the other groups that ate fish 2 to 3 times per month and 1 to 2 times per week, respectively). As the frequency of fish consumption increased, so did the blood mercury concentration. CONCLUSIONS: We found that the blood mercury concentration increases along with fish consumption and this was statistically significant and this fact reveals that fish consumption is positively related to the blood levels of mercury. Accordingly, we need systematic and periodic research on the general population to prevent mercury poisoning, which can be caused by low-level mercury exposure from dietary intake such as chronic fish consumption.

A Study on Olfactory Function in Painters Exposed to Organic Solvent in a Shipyard / 대한산업의학회지

OBJECTIVES: To investigate the effect of the occupational exposure to organic solvent on the olfactory function of shipyard painters; we measured the prevalence of olfactory function impairment between the exposure group and the controls by using the Korean Version of the Sniffin'Stick (KVSS) test through smell, and by analyzing factors related to olfactory alteration. METHODS: The olfactory function of 245 painters exposed to organic solvents was compared to that of 122 unexposed controls. A total of 367 shipyard subjects underwent questionnaire study and the olfactory function test was performed by KVSS test I from April to August 2007. Suspected subjects of abnormal findings were referred to an otorhinolaryngologist. In addition, the Biologic Exposure Index (BEI) and industrial hygiene laboratory data were collected as well as analyzed by job title in the exposure group. RESULTS: The difference in the result of KVSS test I was significantly different from the exposure group and the controls (P<0.05). For the exposure group, reduced olfaction and exposure group were correlated with statistical significance when compared to the controls (P<0.01). Adjusting for work duration, smoking, rhinitis or sinusitis history, exposure of the organic solvent (OR 1.76, 95% CI=1.05-2.96) had a statistically meaningful relationship with decreased olfaction. The data on BEI for the exposure group were collected; the difference in methylhippuric acid was significant between spray workers and others, but did not correlate well with decreased olfaction. CONCLUSION: Occupational exposure to organic solvents in shipyard painters may affect the olfactory function. Therefore, shipyard painters should be monitored on a periodic bases by the quantitative test such as KVSS test. There is no other quantitative testing method or standardized procedure that can objectively diagnose the neurotoxic effect, further enhanced quality research in this field is necessary.

A case of Peripheral Neuropathy After High Electrical Injury / 대한산업의학회지

BACKGROUND: With increasing industrial development, opportunities are growing to contact electricity in the workplace or home. Therefore, the risk of electrical accident has been increased gradually. In general, electrical injuries involve the extremities and result in amputation or severe disability of limbs. Delayed spinal cord injury and peripheral neuropathies following electrical accidents are extremely rare. CASE REPORT: A 32-year-old man with 10 years working experience at a CRT-monitor manufacturer with repetitive exposures to high voltage current visited our hosipital. He complained of left leg weakness and atrophy, and intermittent pain. The symptoms were progressive. Other symptoms occurred such as nocturia, hesitancy, and weak urinary stream. We examined the patient and conducted EMG, L-spine MRI, neurometer test, isokinetic strength test, and physical examination. The results showed neural injuries due to anterior horn lesions or compression of the left femoral nerve pathway, with a consequent diagnosis of neurogenic bladder.

Developing an Occupational Stress Scale for Korean Employees / 대한산업의학회지

BACKGROUND AND PURPOSES: Over the past three decades, numerous studies performed in Korea have reported that job stress is a determinant risk factor for chronic diseases and work disability. Every society has its own culture and occupational climate particular to their organizations, and hence experiences different occupational stress. An occupational stress measurement tool therefore needs to be developed to estimate it objectively. The purpose of this study is to develop and standardize the Korean Occupational Stress Scale (KOSS) which is considered to be unique and specific occupational stressors in Korean employees. Subjects and METHODS: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project: 2002-2004). A total of 12,631 employees from a nationwide sample proportional to the Korean Standard Industrial Classification and the Korean Standard Occupational Classification were administered. The KOSS was developed for 2 years (2002- 2004). In the first year, we collected 255 items from the most popular job stress measurement tools such as JCQ, ERI, NIOSH and OSI, and 44 items derived from the a qualitative study (depth interview). Fortythree items of KOSS, in the second year, were retained for use in the final version of the KOSS by using Delphi and factor analysis. Items were scored using conventional 1-2-3-4 Likert scores for the response categories. RESULTS: We developed eight subscales by using factor analysis and validation process: physical environment (3 items), job demand (8 items), insufficient job control (5 items), interpersonal conflict (4 items), job insecurity (6 items), organizational system (7 items), lack of reward (6 items), and occupational climate (4 items). Together they explained 50.0% of total variance. Internal consistency alpha scores were ranged from 0.51 to 0.82. Twenty-four items of the short form of the KOSS (KOSS-SF) were also developed to estimate job stress in the work setting. Because the levels of the subscales of occupational stress were gender dependent, gender-specific standard norms for both the 43-item full version and the 24-item short form using a quartile for the subscales of KOSS were presented. CONCLUSION: The results of this study suggest that KOSS might be an appropriate measurement scale to estimate occupational stress of Korean employees. Further and more detailed study needs to be conducted to improve the validity of this scale.

Occupational disease surveillance system in Busan, Ulsan, Kyung-Nam area / 대한산업의학회지

OBJECTIVE: Occupational medicine specialists in the Busan, Ulsan and Kyung-Nam areas established an area-based occupational disease surveillance system and used this system to collected case information for the purpose of preventing occupational diseases METHODS: 11 hospitals participated in this system. The authors selected five main diseases, which were hand-arm vibration syndrome (HAVS), work-related musculoskeletal disorder (WRMSD), occupational asthma, occupational skin disease and occupational lung cancer and established their case definitions. All cases were reported on the web, and real time analysis was conducted. RESULTS: Between Apri1 2001 and April 2003, 192 cases of HAVS, 118 cases of WRMSD, 33 cases of occupational asthma, 17 cases of occupational skin disease and 17 cases of occupational lung cancer (for a total of 377 cases of these five main diseases) were reported. Most of the HAVS cases came from shipbuilding, and 172 of them (92.7 %) were associated with grinding. Of the four main types of WRMSD, carpal tunnel syndrome (CTS) was the most prevalent with 46 cases and shipbuilding was also the main industry involved (83.9 %). The ergonomic risk factors involved mainly associated with the hand. In 19 (57.6 %) and 4 (12.1 %) cases of occupational asthma, the agents included isocyanate and welding fume, respectively. 64.7 % of the cases of occupational skin diseases were contact dermatitis, and organic solvents and welding fume were the main agents involved. The causative agents of occupational lung cancer included Cr, welding fume, PAH, Ni, etc. 10 (58.8 %) of the cases were diagnosed as squamous cell carcinoma and 5 (29.4 %) as adenoma. CONCLUSION: This result showed that an area-based occupational disease surveillance system might provide an effective method of evaluating the prevalence of such diseases, however the Busan, Ulsan and Kyung-Nam provinces are too large to be treated as individual areas. Therefore, the authors suggest that each province should establish its own surveillance system.