Man Joong Jeon

The Association between Shift Work and the Metabolic Syndrome in Female Workers

ObjectiveThis study aimed to determine identify any association between shift work and the metabolic syndrome by comparing the prevalence rates of the metabolic syndrome in shift work groups and daytime work groups for female workers.MethodsBased on data from health examinations carried out from April to December of 2012, we selected as our subjects 254 female workers from the Daegu area Dyeing Industrial Complex. We diagnosed the metabolic syndrome using the examination results, and information about age, whether or not they did shift work, job type, smoking habits, drinking habits, exercise habits, and past medical history was collected through self-administered questionnaire surveys and face-to-face interviews. The variables found in a univariate analysis to be significant in the occurrence of the metabolic syndrome - age, drinking habits, exercise habits, and shift work - were included in a logistic regression analysis of the risk of the metabolic syndrome for female workers.ResultsThe prevalence rates of the metabolic syndrome for the total group of study subjects was 11.8%, for daytime workers was 2.8%, and for shift workers was 15.3%. A logistic regression analysis of the odds of the metabolic syndrome for female workers was conducted that included factors associated with the occurrence of the metabolic syndrome: age, drinking habits, exercise habits, and shift work. The results revealed that the odds ratio of the metabolic syndrome in the shift work group, 6.30 (95% CI 1.24-32.15), was significantly higher when compared with the daytime work group.ConclusionShift work appears to have an association with the metabolic syndrome in female workers. Accordingly, we believe that the attention of government agencies and business owners is needed together with the individual practice of health behaviors to manage the metabolic syndrome for the prevention of cardiovascular disease in female shift workers.

Cross-cultural comparison of neurobehavioral performance in Asian workers.

Widely-used neurobehavioral tests have been developed and standardized on Western populations, but studies on subject factors for Asian populations have been very limited. For the effective application and interpretation of neurobehavioral tests in Asian populations, an evaluation of the effects of subject factors, including cultural background, is necessary. A cross-cultural study was conducted to evaluate the effects of cultural background and the interaction between cultural background and education on neurobehavioral tests in Asian populations. The Korean version of the Swedish Performance Evaluation System (Simple Reaction Time, Symbol Digit, and Finger Tapping Speed) and a pegboard test were administered to 537 workers who were not exposed to chemicals at work from Fareast (Korea and Chinese), Central (Uzbekistan and Tajikistan), and South Asia (Sri Lanka and Indonesia). The Fareast Asian group exhibited better performance in adjusted test scores than other Asian groups, achieving significance for Symbol Digit and Finger Tapping Speed in both genders. The magnitude of the effect of cultural background on Symbol Digit was comparable to the effect of about 10 years of education. Cultural background did not modify the relation between years of education and Symbol Digit in either males or females. This study may provide the first evidence that cultural background has a large impact on neurobehavioral test performance, even within Asian populations, and suggests that cultural background is a critical confounding factor that must be controlled in epidemiologic studies which include Asian populations in the sample.

Evaluation of mercury exposure level, clinical diagnosis and treatment for mercury intoxication

Mercury occurs in various chemical forms, and it is different to health effects according to chemical forms. In consideration of the point, the evaluation of the mercury exposure to human distinguished from occupational and environmental exposure.With strict to manage occupational exposure in factory, it is declined mercury intoxication cases by metallic and inorganic mercury inhalation to occupational exposure. It is increasing to importance in environmental exposure and public health.The focus on the health impact of exposure to mercury is more on chronic, low or moderate grade exposure—albeit a topic of great controversy—, not high concentration exposure by methylmercury, which caused Minamata disease.Recently, the issue of mercury toxicity according to the mercury exposure level, health effects as well as the determination of what mercury levels affect health are in the spotlight and under active discussion. Evaluating the health effects and Biomarker of mercury exposure and establishing diagnosis and treatment standards are very difficult.It can implement that evaluating mercury exposure level for diagnosis by a provocation test uses chelating agent and conducting to appropriate therapy according to the result. but, indications for the therapy of chelating agents with mercury exposure have not yet been fully established.The therapy to symptomatic patients with mercury poisoning is chelating agents, combination therapy with chelating agents, plasma exchange, hemodialysis, plasmapheresis. But the further evaluations are necessary for the effects and side effects with each therapy.

Evaluation and management of lead exposure

Lead, which is widely used in industry, is a common element found in low concentrations in the Earth’s crust. Implementations to reduce environmental lead concentrations have resulted in a considerable reduction of lead levels in the environment (air) and a sustained reduction in the blood lead levels of the average citizen. However, people are still being exposed to lead through a variety of routes in everyday commodities.Lead causes health problems such as toxicity of the liver, kidneys, hematopoietic system, and nervous system. Having a carcinogenic risk as well, the IARC classifies inorganic lead compounds as probably carcinogenic to humans (Group 2A). Occupational lead poisonings have decreased due to the efforts to reduce the lead concentrations in the working environment. In contrast, health hazards associated with long-term environmental exposure to low concentrations of lead have been reported steadily. In particular, chronic exposure to low concentrations of lead has been reported to induce cognitive behavioral disturbances in children.It is almost impossible to remove lead completely from the human body, and it is not easy to treat health hazards due to lead exposure. Therefore, reduction and prevention of lead exposure are very important. We reviewed the toxicity and health hazards, monitoring and evaluation, and management of lead exposure.

A Case of Lead Poisoning due to a Mixture of Talisman Ash

BackgroundLead is a metal that has no biological function useful for the human body. In Korea, non-occupational exposure to lead has mostly occurred through taking oriental medicine. However, in this paper we report a case of lead poisoning caused by ingesting talisman material.Case presentationA 16-year-old male patient complained of severe abdominal pain after taking cinnabar, a talisman material. He was diagnosed with lead poisoning accompanied by acute hepatitis. We confirmed that the cinnabar the patient took contained about 10% elemental lead. After symptom management, the patients’ symptoms, liver function test results, and blood lead concentration level improved.ConclusionLead poisoning can be accompanied by hepatitis, although rarely. As we have confirmed that cinnabar as a talisman material is harmful to the human body, measures to prevent its misuse are needed.

The association between long working hours and the metabolic syndrome: evidences from the 5th Korean National Health and Nutrition Examination Survey of 2010 and 2012

ObjectivesThis study was conducted in order to evaluate the association between the working hours of Korean employees and the metabolic syndrome and the effects of long working hours on metabolic syndrome based on the 5th Korean National Health and Nutrition Examination Survey (2010-2012).MethodsBased on the 5th Korean National Health and Nutrition Examination Survey (2010-2012), 4,456 Korean employees without shift work, aged over 15, who work 30 hours or more per week were targeted in this study. The association between the general characteristics, including age, smoking, alcohol drinking, exercise, and the metabolic syndrome criteria defined by International Diabetes Federation (IDF) and weekly working hours were analyzed. In addition, the association between weekly working hours and the metabolic syndrome of the subjects stratified by gender was analyzed through multiple logistic regression analyses and generalized linear mixed model after adjusting the general characteristics.ResultsIn the results of stratified analysis by gender, in male subjects, in comparison with the 30-39 weekly working hours group, there were no significant adjusted odds ratios to the other working hours groups. In female subjects, in comparison with the 30-39 weekly working hours group, there were no significant adjusted odds ratios to the other working hours groups. In addition, no trend associations were observed among weekly working hour groups in both stratified genders.ConclusionNo significant differences in prevalence of metabolic syndrome of the subjects stratified by gender were found according to weekly increasing working hours. However, due to some limitations of this study, further prospective studies may be necessary for verification.

Evaluation of reliability of computerized neurobehavioral tests in Korean children.

Neurobehavioral tests are among the most efficient methods of identifying the adverse health effects of neurotoxicants. The reliability of neurobehavioral tests may be affected by racial or cultural backgrounds, but the widely used computerized neurobehavioral tests have been developed and standardized for Western children. It is thus necessary to assess the reliability of the existing computerized neurobehavioral tests for Korean children. For this reason, 254 healthy 7- to 8-year-old Korean children completed a neurobehavioral test-retest, with the test and retest held two months apart. Six neurobehavioral test items adapted from Korean Computerized Neurobehavioral Tests (KCNT) and modified to match the childrens ability levels: Simple Reaction Time, Choice Reaction Time, Color Word Vigilance, Addition, Symbol Digit, and Finger Tapping Speed. The test reliability was assessed using the Pearson product-moment correlation coefficient (r) and the intraclass correlation coefficient (ICC). The ICCs ranged from 0.46 to 0.84 and were very similar to the Pearson coefficients. High reliability was detected in Symbol Digit (r=0.84, ICC=0.83), followed by the Finger Tapping Speed of the dominant hand (r=0.67, ICC=0.67) and of the non-dominant hand (r=0.65, ICC=0.65). The study findings suggest that the reliability of most computerized neurobehavioral tests is appropriate for epidemiological researches on Korean children, and that Symbol Digit and Finger Tapping Speed are more satisfactory bases for the periodic examination of neurobehavioral performance. These findings can also be useful in the future assembly of a neurobehavioral test battery, by providing more stable neurobehavioral test items for Korean children.

Effects of computer familiarity and computer type on the performance of Korean computerized neurobehavioral test

BackgroundIt is thought that computer familiarity has increased significantly since 2004 as well as the use of computers. This study aimed to evaluate the effects of computer familiarity and types of keyboard and computer on the performance of the Korean computerized neurobehavioral test (KCNT), and to identify which parameters of KCNT were affected by aforementioned factors.MethodsA total of 85 subjects were classified into three groups of computer familiarity by Korean typing speed. Their age, gender and the level of education were also collected. The parameters of KCNT included simple reaction time, choice reaction time, addition, symbol digit, and finger tapping speed. The test was conducted using three types of computers: a laptop computer, a laptop computer with a simplified keyboard, and a desktop computer with a simplified keyboard.ResultsParameters including the simple reaction time, choice reaction time, addition, and symbol digit, and the finger tapping speed of non-dominant hand showed no significant differences in the results among the three groups by computer familiarity after age and educational years were controlled as covariates. The mean reaction time of the simple reaction time and the choice reaction time with a simplified keyboard was significantly shorter compared to that with a typical keyboard. With regard to type of computer, the mean reaction time of the simple reaction time and the choice reaction time was significantly reduced when performed with the desktop computer with a simplified keyboard.ConclusionsUnlike previous study results, the choice reaction time, the addition, and the finger tapping speed of dominant hand were the only parameters affected by the computer familiarity. Both the type of keyboard and the type of computer significantly influenced the simple reaction time and the choice reaction time. Therefore, it is recommended to use a desktop computer with a simplified keyboard for such parameters.

Analysis of causes of injuries among children in Daegu, Korea

Purpose The purpose of this study was to determine the mechanisms and exact causes of injuries to children by analyzing the medical records of children who visited emergency medical centers. Methods We reviewed the medical records of 7,114 pediatric patients (aged below 15 years) who visited the emergency care center (ECC) of a Yeungnam university hospital in Daegu between January 2007 and December 2009. Results Among the pediatric patients who visited the ECC, 1,526 (27.2%) were admitted for injuries (boys, 979 [64.2%] and girls, 547 [35.8%]); the boy-to-girl ratio in this study population was 1.8:1. The proportion of boys was higher than that of girls over all age ranges, except for children aged less than 1 year. The highest incidence of injury due to slipping (20.5%) was noted in the 1-year-old group, and nearly half the total number of cases (49.3%) involved children who were under 4 years of age. Of the sites of injury, 999 involved the head and face (73.7%) and 134 involved the hand and wrist (9.9%). Seventy-one injuries (5.7%) occurred on the bed, 70 (5.6%) at the door, and 67 (5.3%) on the stairs. Of the approximately 250 types of injuries classified by cause, 17 accounted for 50.4% of all the injuries. Conclusion The cause of injury could be attributed to approximately 20 causes in more than half the cases of pediatric injuries. A classification of the types of injuries and the development of appropriate preventive strategies can help avoid such injuries.

Performance assessment on the Korean Computerized Neurobehavioral Test using a mobile device and a conventional computer: an experimental study

BackgroundThe Korean Computerized Neurobehavioral Test (KCNT) is a psychological assessment tool used as part of Workers’ Special Health Examinations in Korea. Due to the spread of mobile technology, this study aimed to compare results of the KCNT administered on a tablet PC versus a desktop computer, and, therefore, assess the clinical applicability of mobile devices.MethodsA total of 72 participants enrolled in this study. Their age, sex, and years of formal education were collected during an interview, as well as their typing speed. The test battery comprised five subtests: Simple Reaction Time test, Choice Reaction Time test, Digit Addition test, Symbol-Digit Substitution test, and Finger Tapping Speed test. Participants repeated the KCNT test battery in a randomly assigned order using four different testing systems: a desktop computer equipped with a conventional 106-key keyboard (System 1), a desktop computer equipped with a simplified keyboard (System 2), a tablet PC with a simplified 17-key on-screen keyboard (System 3), and a tablet PC equipped with a simplified keyboard (System 4).ResultsResults of the Digit Addition test did not differ significantly for different testing systems. In contrast, results of the Simple Reaction Time test, Choice Reaction Time test, Symbol-Digit Substitution test, and Finger Tapping test were lower for the tablet PC (Systems 3 and 4) compared to the desktop computer (Systems 1 and 2). Systems 1 and 2 did not show significantly different results. Performance on System 3 was inferior to that on System 4, only for the Choice Reaction Time test and Finger Tapping Speed test. There were also significant differences in performance by computer familiarity when adjusted for age and education; however, the performance of each group on the test systems showed similar patterns.ConclusionsIt is not recommended to use a tablet PC to administer the KCNT to evaluate neurobehavioral performance for the Simple Reaction Time test and Choice Reaction Time test; however, tablet PCs with an on-screen keyboard may be used to perform the Digit Addition test, and the Symbol-Digit Substitution test and Finger Tapping Speed test to a limited degree.