OBJECTIVES: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease involving the upper and lower motor neuron of the brain and spinal cord, leading ultimately to death due to respiratory failure in most cases. The etiology of ALS is currently unknown, but several studies show that lead exposure might be one of the potential environmental causes of ALS. In this perspective, we introduce a case involving an ALS patient exposed to lead while maintaining mechanical equipment in a waste treatment plant. METHODS: The patient was interviewed and his medical records were investigated to confirm the final diagnosis of ALS. The results of his health examination and working environment measurement were reviewed in order to evaluate the relation of his work with ALS. We also performed an analysis of lead concentration from samples taken from his workplace when we visited the plant to survey the work environment. RESULTS: Based on the patient's clinical information, work environment, relatively high level of blood lead concentration, and several studies proposing the occupational relationship between lead and ALS, his ALS may possibly have been caused by lead exposure at his workplace. CONCLUSIONS: Given the recent situation where the causal association between lead exposure and ALS is still unclear, this case report could be used as a basis to support the relevance of lead exposure with ALS, and to help improve the health and work environment of other workers who are likely to be exposed to lead.
Amyotrophic Lateral Sclerosis ; Brain ; Humans ; Medical Records ; Motor Neurons ; Neurodegenerative Diseases ; Occupational Exposure ; Plants ; Respiratory Insufficiency ; Spinal Cord

OBJECTIVES: A standardized questionnaire is not available for use as a screening tool to assess individuals with MCS/IEI in Korea. The QEESI(c), originally developed by Miller & Prihoda in 1998, helps researchers, doctors, and their patients identify individuals with MCS/IEI. Therefore, this study was conducted in order to create a Korean version of the QEESI(c) and evaluate whether this Korean version could be used as an effective MCS/IEI screening tool in Korea. METHODS: The Korean version of the QEESI(c) was developed using a six-step approach: permission, forward translation, the first quality control, backward translation, cognitive debriefing and the second quality control, final proof reading. In order to collect data, we have done a sample survey in certain parts of Korea. A household was used as the sampling unit; we extracted random samples in each survey cluster and then interviewed two adults over 19 years of age living in each sampled household. A total of 300 subjects were recruited from the general population in local community. The factor structure in the Korean version of the QEESI was analyzed with 40 items on four sub-scales except for the 10 items in masking index using principal components analysis with Varimax rotation. A convergent validity test two sub-scales: chemical intolerance and symptom severity. We carefully compared the chemical intolerance with Nordin's chemical sensitivity scale and the symptom severity with Cho's subjective symptom score. RESULTS: The results showed that the 40 items on the four sub-scales,' chemical intolerances',' symptom severity', 'life impact', and 'other intolerances', were consistent with those reported for the US population by Miller and Prihoda. The convergent validity wes very good (r=0.4; p<0.001, r=0.5; p<0.001, respectively). A good internal consistency (Cronbach' alpha=0.86~0.96) and test-retest reliability (r=0.87~0.90) were found in all scales, except for the internal consistency in the masking index. CONCLUSIONS: The Korean version QEESI(c) showed a good reliability and validity. It should be necessary to conduct a MCS/IEI study adopting Korean version QEESI(c).
Adult ; Environmental Exposure ; Family Characteristics ; Humans ; Korea ; Masks ; Mass Screening ; Multiple Chemical Sensitivity ; Quality Control ; Questionnaires ; Reproducibility of Results ; Weights and Measures

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

OBJECTIVES: The objective of this study was to determine the relationship of physical and psychosocial risk factors to work-related musculoskeletal upper extremity symptoms amongst automobile manufacturing workers. METHODS: The cross-sectional study was conducted using male automobile manufacturing workers in order to examine the relationship of physical and psychosocial risk factors to work-related musculoskeletal upper extremity symptoms. A total of 1,793 male workers were asked to complete a self-administered questionnaire. The questionnaire consisted of questions regarding general characteristics, health related behaviors, work-related characteristics, job stress, ergonomic risk factors, and the presence of musculoskeletal symptoms (neck, shoulder, arm, and hand). Work-related musculoskeletal symptoms were evaluated using the National Institute of Occupational Safety and Health (NIOSH) surveillance criteria. In order to measure the physical risk factors, the American National Standard Institute (ANSI) Z-365 Quick checklist was incorporated into the questionnaire. Job stressors were measured using the Korean Occupational Stress Scale (KOSS). A binary logistic regression analysis was performed that examined the relationship of physical and psychosocial risk factors to musculoskeletal symptoms. RESULTS: The result showed that the physical and psychosocial risk factors were associated with musculoskeletal upper extremity symptoms. The workers with high physical risk factors reported more musculoskeletal symptoms than those having low physical risk factors (OR: 2.37, 95% CI: 1.56~3.62). The workers with high job stress were more likely to have an increased risk of musculoskeletal upper extremity symptom compared to those with normal job stress (OR: 2.65, 95% CI: 2.03~3.47). A significant relationship between the combined effects of physical and psychosocial risk factors on musculoskeletal upper extremity symptoms was also found. The workers exposed to high physical risk factors, high job stress, and long working hours were more likely to report musculoskeletal symptoms than those having low physical risk factors, normal job stress and moderate working hours(OR: 2.37, 95% CI: 1.56~3.62). CONCLUSIONS: The results suggest that some physical and psychosocial risk factors increase the risk of work-related musculoskeletal upper extremity symptoms amongst automobile manufacturing workers. In order to prevent or reduce musculoskeletal disorders amongst automobile manufacturing workers, it is strongly recommended to manage the physical psychosocial risks occurring in the workplace.
Arm ; Automobiles ; Checklist ; Cross-Sectional Studies ; Human Engineering ; Humans ; Logistic Models ; Male ; Occupational Health ; Questionnaires ; Risk Factors ; Shoulder ; Upper Extremity

OBJECTIVES: Automobile exhaust gases contain benzene and toluene, which are excreted in human urine as trans,trans-muconic acid and hippuric acid, respectively. Sorbic acid and benzoic acid, used as food preservatives, are also metabolized into trans,trans-muconic acid and hippuric acid in the human body. The purpose of this study is to estimate the level of benzene and toluene exposure according to the commuting mode and duration, residential environment, and preservative-added foods intake in university students who are not occupationally exposed to benzene or toluene. METHODS: Spot urine samples were collected from 211 university students who had no occupational exposure to volatile organic compounds. Information about their smoking history, residence type, traffic environments, commuting mode and duration, and their intake of bottled or canned food or beverages was gathered through a self-administered questionnaire. Urinary concentrations of trans,trans-muconic acid and hippuric acid were measured and statistically correlated to the individual's life style factors. RESULTS: There was no significant difference in the urinary concentrations of trans,trans-muconic acid or hippuric acid according to the smoking history. Mean urinary concentration of hippuric acid in females was higher than that found in males. Subjects living in districts with a population density of 1,000~4,999 people/km2 showed the highest urinary hippuric acid level; individuals living in cities of 5,000~9,999 people/km2 population density were next. The mean urinary trans,trans-muconic acid concentration was higher in students who were living where traffic jams are common compared to those who did not, and in subjects whose residence were within 149 m from a 4-lane road compared to those whose residence was not. However, neither mode nor duration of the commute showed any effect on the urinary trans,trans-muconic acid or hippuric acid concentrations of the students. Urinary hippuric acid levels increased when consuming canned fruit or canned coffee, and urinary trans,trans-muconic acid levels increased when consuming fruit juices or pickled radishes. CONCLUSIONS: The inhalation of vehicle exhaust and the ingestion of canned or pickled food may increase urinary hippuric acid and trans,trans-muconic acid levels in individuals who are not occupationally exposed to benzene or toluene.
Benzene ; Benzoic Acid ; Beverages ; Coffee ; Eating ; Female ; Food Preservatives ; Food, Preserved ; Fruit ; Gases ; Hippurates ; Human Body ; Humans ; Inhalation ; Life Style ; Male ; Occupational Exposure ; Occupations ; Population Density ; Questionnaires ; Smoke ; Smoking ; Sorbic Acid ; Toluene ; Transportation ; Vehicle Emissions ; Volatile Organic Compounds

OBJECTIVES: The aim of this study was to evaluate the relationship between shift work and work-related injuries in a representative sample of Korean workers. METHODS: We used data from the Korean Working Condition Survey of 2006. The participants were 7,075 Korean workers 15 to 64 years of age. Logistic regression was employed to estimate the relationship between shift work and work-related injury using the SAS version 9.2 program. RESULTS: Shift work was significantly related to work-related injuries compared to non-shift workers(OR 2.40, 95% CI=1.65~3.48). When personal and occupational risk factors were accounted for, shift work had a statistically meaningful relationship with work-related injuries compared to non-shift work(OR 1.79, 95% CI=1.20~2.66). CONCLUSIONS: In this study, shift workers appear to have a higher risk of work-related injuries compared to non-shift workers. Work-related injuries in shift workers could be attributed to circadian rhythm disorder and sleep problems. Suitable arrangements that ensure flexible working times are needed for shift workers. Further study will be needed to identify and mitigate work-related injuries among shift workers.
Chronobiology Disorders ; Dietary Sucrose ; Humans ; Logistic Models ; Phenothiazines ; Risk Factors

OBJECTIVES: To determine the level of aircraft noise exposure and how it relates to hearing loss, and to investigate the association between noise exposure and anxiety and depression in subjects residing adjacent to a military airbase. METHODS: The study was conducted upon 898 inhabitants between the ages of 30-79, living near the military airbase in Jeonra-do. The subjects were divided into three noise-exposure groups: high-exposure, low-exposure, and a control group. The cut-values were 80 and 60 on the Weighted Equivalent Continuous Perceived Noise Level scale. A self-administered questionnaire including the Beck Anxiety Inventory (BAI) and the Beck Depression Inventory (BDI) were completed. Pure tone audiometry tests were performed. RESULTS: Hearing loss prevalence was defined by a >40 dB loss in bilateral ears or in one ear; the difference of <15 dB compared to the better side was 30.8%. The mean BAI/BDI score was 18.9+/-14.3/18.7+/-11.6, the number of abnormal subjects with BAIs > or =22 was 317 (35.3%), with BDIs > or =21 was 347 (38.6%). The pure tone average, BAI, and BDI scores were higher in the noise-exposure groups compared to the control. The BAI/BDI abnormal subjects showed a higher hearing threshold shift level compared to the normal scored subjects. The odd ratios for anxiety was significantly high in both noise exposure groups and the hearing loss, for depression was significantly high in high-exposure group and hearing loss. CONCLUSIONS: Anxiety and depression were higher when exposure to high-level noise and further complicated by hearing loss. Further investigation is needed to determine the cause-effect relationship.
Aircraft ; Anxiety ; Audiometry ; Depression ; Ear ; Hearing ; Hearing Loss ; Humans ; Military Personnel ; Noise ; Prevalence ; Questionnaires

OBJECTIVES: The aim of this study was to investigate the relationship between job stress and the willingness of male workers in small and medium scale industry to cease smoking. METHODS: A structured self-reported questionnaire was used to assess each respondent's socio-demographics, job stress, and the will to cease smoking. A KOSS (Korean Occupational Stress Scale)- based questionnaire survey was conducted which targeted 4,435 male workers at 69 small and medium scale industries. 2,840 men returned these questionnaires with 1,663 of them being smokers. We analyzed 1,345 of the smoker returns. We estimated the relationship between the will to cease smoking and the employee job stress factors using logistic regression analyses. RESULTS: After adjusting for education, exercise, and tobacco use per day, the logistic regression analysis revealed a significantly positive association with the will to cease smoking and job stress. The odds ratios regarding insufficient job control were at 1.69 (95% CI, 1.26~2.27), organizational system at 1.37 (95% CI, 1.03~1.82), and lack of reward at 1.37 (95% CI, 1.03~1.82). CONCLUSIONS: These results indicated that job stress may play a significant role in the will to cease smoking. Further preventive efforts and studies are needed in order to reduce job stress.
Humans ; Logistic Models ; Male ; Odds Ratio ; Questionnaires ; Reward ; Smoke ; Smoking ; Smoking Cessation ; Tobacco

OBJECTIVES: The investigation of the degree of the relationship according to body part between occupational stress and musculoskeletal symptoms in the neck, shoulder, elbow, and hands of workers performing computer tasks. METHODS: In August and September 2009, we conducted a survey of 529 public office workers employed by the National Health Insurance Corporation using structured questionnaires in order to find demographic factors, work related factors, job stress, physical computer task load and musculoskeletal symptoms. Nordic musculoskeletal questionnaire, Quick DASH (Disabilities of the Arm, Shoulder and Hand Score), and the Northwick Park neck pain questionnaire were all used to evaluate their musculoskeletal symptoms. The presence of symptoms segregated by body part determined the dependent variables. The degree of job stress and other confounder variables determined the independent variables. We calculated the odds ratio employing multiple logistic regressions. RESULTS: A score of > or =5 in the VAS (Visual Analogue Scale) 10-point scale and the presence of symptoms lasting at least 1 week determined the musculoskeletal symptom group in regards to the Nordic musculoskeletal questionnaire. The neck pain odds ratio was adjusted by sex, age, work hours, employment duration, physical computer task load and depression. It was determined to be 2.92 (95% CI 1.76~4.84) in the higher to lower occupational stress group. The shoulder pain odds ratio was 1.96 (95% CI 1.18~3.24), elbow pain 0.55 (95% CI 0.21~1.43), and hand pain 1.71 (95% CI 0.99~2.95). A score of > or =10 in the 100-unit scale determined the musculoskeletal symptom group in regards to the Northwick Park neck pain questionnaire and the Quick DASH. The neck symptom odds ratio was 2.73 (95% CI 1.66~4.49) and the upper extremity symptom figure was 2.18 (95% CI 1.29~3.68). CONCLUSIONS: This study suggests that the relevance between neck and shoulder symptoms and occupational stress was obvious, however the relevance between elbow and hand pain and job stress was not as clear or ambiguous.
Arm ; Demography ; Depression ; Elbow ; Employment ; Hand ; Musculoskeletal Diseases ; National Health Programs ; Neck ; Neck Pain ; Odds Ratio ; Questionnaires ; Shoulder ; Shoulder Pain ; Upper Extremity

OBJECTIVES: This study is conducted to investigate the prevalence of work-related back pain among Driving and Transport Related Occupations and to identify the risk of mechanical factors and psychosocial factors. METHODS: Subjects were 779 operators and drivers of transportation vehicles selected from respondents from the 1st Korean Working condition survey. The occupation risk factors, including socioeconomic, ergonomic, psychosocial factors, were investigated. We used the multiple logistic regression analysis to determine the relationship between risk factors and low back pain. RESULTS: The prevalence of self-reported work-related low back pain was 27.7%. Adjusting for confounding factors, we determined that whole body vibration(OR 1.64 95% CI: 1.09~2.48), tiring posture(OR 5.18, 95% CI: 3.01~8.93), extended work(OR 1.91, 95% CI: 1.20~3.04), night-time work(OR 2.79, 95% CI: 1.86~4.19), evening work(OR 2.82, 95% CI: 1.78~4.46), shift work(OR 2.35, 95% CI: 1.30~4.26), job dissatisfaction (OR 2.65, 95% CI: 1.76~3.99), and experiencing physical violence at work(OR 5.31, 95% CI: 1.25~22.67) had meaningful relationships with low back pain. CONCLUSIONS: We found that the psychosocial risk factors were the most significant factors among drivers of transportation vehicles in Korea. Therefore, we suggest a health promotion program to relieve Job stress as a solution to prevent and control low back pain among drivers of transportation vehicles in Korea.
Back Pain ; Data Collection ; Health Promotion ; Korea ; Logistic Models ; Low Back Pain ; Occupations ; Prevalence ; Risk Factors ; Transportation ; Violence