Fifteen Years After the Gozan-Dong Glass Fiber Outbreak, Incheon in 1995 / 예방의학회지

OBJECTIVES: In 1995, an outbreak survey in Gozan-dong concluded that an association between fiberglass exposure in drinking water and cancer outbreak cannot be established. This study follows the subjects from a study in 1995 using a data linkage method to examine whether an association existed. The authors will address the potential benefits and methodological issues following outbreak surveys using data linkage, particularly when informed consent is absent. METHODS: This is a follow-up study of 697 (30 exposed) individuals out of the original 888 (31 exposed) participants (78.5%) from 1995 to 2007 assessing the cancer outcomes and deaths of these individuals. The National Cancer Registry (KNCR) and death certificate data were linked using the ID numbers of the participants. The standardized incidence ratio (SIR) and standardized mortality ratio (SMR) from cancers were calculated by the KNCR. RESULTS: The SIR values for all cancer or gastrointestinal cancer (GI) occurrences were the lowest in the exposed group (SIR, 0.73; 95% CI, 0.10 to 5.21; 0.00 for GI), while the two control groups (control 1: external, control 2: internal) showed slight increases in their SIR values (SIR, 1.18 and 1.27 for all cancers; 1.62 and 1.46 for GI). All lacked statistical significance. All-cause mortality levels for the three groups showed the same pattern (SMR 0.37, 1.29, and 1.11). CONCLUSIONS: This study did not refute a finding of non-association with a 13-year follow-up. Considering that many outbreak surveys are associated with a small sample size and a cross-sectional design, follow-up studies that utilize data linkage should become standard procedure.

Effects of Volatile Organic Compounds, and Formaldehyde on Heart Rate Variability among Elderly People in Seoul / 대한산업의학회지

OBJECTIVES: The purpose of the present study was to investigate the effects of volatile organic compounds, and formaldehyde on heart rate variability among elderly people who are vulnerable to ambient pollution. METHODS: From May to August of 2009, 57 subjects older than 60 years were recruited in this study. Indoor air pollutants (volatile organic compounds and formaldehyde) were measured by a personal passive sampler. Heart rate variability (HRV) was measured in the sitting position for five minutes and assessed by time-domain and frequency-domain. RESULTS: Multiple linear regression analysis showed significantly less low-frequency (LF) and high-frequency (HF) associated with elevated benzene levels. Exposure to toluene was associated with decreases in the Standard deviation of the NN intervals (SDNN) and LF. SDNN and LF were negatively associated with the increment of ethylbenzene levels. CONCLUSIONS: An adverse effect on cardiovascular function caused by volatile organic compounds was observed among the elderly people of Seoul even though indoor air pollutant levels were lower than the yearly average guideline for indoor air quality in Korea.

Association between Cadmium and Cognitive Function in the Elderly / 대한산업의학회지

OBJECTIVES: We conducted this study to investigate the relationship between the blood concentration of cadmium and cognitive function in elderly Koreans. METHODS: This research is a part of the Korean Elderly Environmental Panel Study (KEEPS). A total of 403 subjects were enrolled and analyzed from August 2008 through August 2010. Demographic information and medical histories were obtained using a questionnaire. Blood concentration of cadmium and Mini-Mental State Examination (MMSE) with Functional Activities Questionnaire (FAQ) were evaluated for each subject. RESULTS: The mean age of subjects was 70.67 (SD 5.18, n=403) and 72% were female. The mean blood cadmium level was 1.22 microg/dl (SD 0.56), mean MMSE score was 25.12 out of 30 and mean FAQ score was 2.03 out of 30. Using linear regression analysis to estimate the relationship between blood cadmium concentration and MMSE and FAQ, we observed a significant association between log transformed values of blood cadmium levels and MMSE (p<0.002) or FAQ (p=0.005) scores. After adjusting for age, sex, level of education, alcohol consumption and smoking habits, the relationship between blood cadmium concentration and MMSE and FAQ scores ramained statistically significant (p=0.033 and 0.029, respectively). CONCLUSIONS: These results suggest that blood cadmium concentration is strongly associated with cognitive function and functional activity in the elderly.

Relationship Between Urinary t, t-muconic Acid and Insulin Resistance in the Elderly / 대한산업의학회지

OBJECTIVES: To examine the associations between the urinary t, t-muconic acid (t, t-MA) concentration and three indices of insulin resistance; namely, the homeostasis assessment of insulin resistance (HOMA-IR) index, blood insulin level and fasting glucose level. METHODS: A panel study was performed on the elderly at a public health care center population in the northern area of Seoul between 2008 and 2010. The participants were 560 elderly, over 60 years of age whose urinary t, t-MA and insulin resistance indices had been measured; questionnaires were completed by these participants. A generalized linear mixed (GLM) analysis was adjusted for age, sex, drinking, urinary cotinine, exercise, vitamin intake and body mass index, at a significance level of p<0.05. RESULTS: A total of 411 participants were finally analyzed after excluding those with diabetes and only one visit to the public health care center. Higher urinary t, t-MA concentrations were linearly associated with the HOMA-IR index, blood insulin level and fasting glucose level in the simple and fully adjusted GLM models. Although there were few limitations, a portion of insulin resistance was proven to be explained by exposure to benzene using r-squared. A significant relationship was also observed between urinary t, t-MA and malondialdehyde (MDA) using the same GLM models. CONCLUSIONS: Urinary t, t-MA is related to the development of insulin resistance which is a key factor for development of diabetes and its complications induced by oxidative stress.

Hot Tub Lung Due to Mycobacterium Avium Complex in a Public Bath / 대한산업의학회지

BACKGROUND: Hot tub lung is a hypersensitivity pneumonitis caused by nontuberculous mycobacteria (NTM); the primary causative agent is Mycobacterium avium complex (MAC) post contaminated water exposure. Recently, 2 cases of hot tub lung were found in public bath bodyscrubbers working in Korea. However, the disease causing NTM was not identified in these cases. Here, we reported one case, along with clinical diagnostic approach to occupational medicine throughout worksite investigation. CASE: A 53 year-old woman working in the public bath for 13 months' duration developed shortness of breath. She had been cleaning the locker room, several pools and floors every day, and using scrubbers with detergent and warm water. After examination, the patient was diagnosed with hypersensitivity pneumonitis based on high resolution computerized tomography and lung biopsy. Because the Mycobacterium avium was identified in both the patient's sputum and the warm pool, she was diagnosed with hot tub lung due to MAC. CONCLUSION: Hot tub lung due to MAC was confirmed in public bath housekeeper. However, few cases have been reported, even though there are many cases. To prevent damages caused by hot tub lung, general environmental management such as ventilation and cleaning is important for bath operators. Likewise, awareness needs to be increased in workers with potential NTM environmental exposure and in clinicians through education about hot tub lung in order to reduce adverse harm from misdiagnosis and mistreatment of tuberculosis.

Development of the Korean Academy of Medical Sciences Guideline for Rating Physical Impairment

Systematic and effective welfare for the disabled is possible when there are scientific and objective criteria demonstrating either presence or severity of the impairment. We need our own scientific criteria suitable for our culture and society, since the impairment is influenced by them. In 2007, we established the Developing Committee of Korean Academy of Medical Sciences (KAMS) Guideline for Impairment Rating under KAMS supervision. We included all fixed and permanent physical impairments after a sufficient medical treatment. The impairment should be stable and medically measurable. If not, it should be reevaluated later. We benchmarked the American Medical Association Guides. The KAMS Guideline should be scientific, objective, valid, reasonable and practical. In particular, we tried to secure objectivity. We developed the KAMS Guideline for Impairment Rating.

The Effects of Particulate Matter on Respiratory Function of Schoolchildren in Jeju: A Panel Study / 대한산업의학회지

OBJECTIVE: To evaluate the changes in respiratory function associated with daily changes in particulate pollution. METHODS: A total of 105 healthy schoolchildren of fourth and fifth grade elementary school age performed peak expiratory flow rates (PEFR) during 2 periods (May 14~June 15, Oct 22~Nov 23). We monitored concomitant ambient particulate matter (PM) levels during the periods. RESULTS: An elevation PM(10) level of 1 microgram/m) led to decreases in PEFR of 0.20 L/min. A 1 microgram/m3 elevation of PM(2.5) led to a decrease of 0.36 L/min in PEFR. In addition, 1 day lag was associated with PM(10) levels and PEFR changes, and PM(2.5) showed the same result. The metal levels determined at PM(10) and PM(2.5) were found to be associated with decreased respiratory function. CONCLUSIONS: An association between respiratory function and particulate pollution was observed when particulate pollutant levels were lower than the yearly average National Ambient Air Quality Standard in the Korea(50 microgram/m3).

EDITOR'S NOTE-About This Supplement

No abstract available.

Effects of Long-term Fluoride in Drinking Water on Risks of Hip Fracture of the Elderly: An Ecologic Study Based on Database of Hospitalization Episodes / 예방의학회지

OBJECTIVES: Fluoridation of drinking water is known to decrease dental caries, particularly in children. However, the effects of fluoridated water on bone over several decades are still in controversy. To assess the risk of hip fracture related to water fluoridation, we evaluated the hip fracture-related hospitalizations of the elderly between a fluoridated city and non-fluoridated cities in Korea. METHODS: Cheongju as a fluoridated area and Chungju, Chuncheon, Suwon, Wonju as non-fluoridated areas were chosen for the study. We established a database of hip fracture hospitalization episode based on the claims data submitted to the Health Insurance Review Agency from January 1995 to December 2002. The hip fracture hospitalization episodes that satisfied the conditions were those that occurred in patients over 65 years old, the injuries had a hip fracture code (ICD-9 820, ICD-10 S72) and the patients were hospitalized for at least 7days. A total of 80,558 cases of hip fracture hospitalization episodes were analyzed. RESULTS: The admission rates for hip fracture increased with the age of the men and women in both a fluoridated city and the non-fluoridated cities (p<0.01). The relative risk of hip fracture increased significantly both for men and women as their age increased. However, any difference in the hip fracture admission rates was not consistently observed between the fluoridated city and the nonfluoridated cities. CONCLUSIONS: We cannot conclude that fluoridation of drinking water increases the risk of hip fracture in the elderly.

EDITOR'S NOTE - About This Supplement

No abstract available.

Trend of the Anthropometric Indices Among Adolescents in a Urban and a Rural Area Over the Period 1996~2005 / 한국역학회지

This study investigated the secular trend of anthropometric parameters of 2,153 high school students in one urban and one rural area in Korea. The cross-sectional data was collected in 1996 and 2005 in Seoul and Gyung-gi province. As a result, the height of boys has increased by 2cm, whereas the weight has increased by 6.3kg from 1996 to 2005. By contrast, those parameters, including height or weight, did not change in girls. The prevalence of obesity has been more than doubled from 9.3% in 1996 to 20.5% in 2005 in boys; while that of girls was almost same for the same period (1998, 11.1%; 2005, 11.4%). In particular, the greater increase of obesity among boys was found in urban, which implicates the importance of environmental factor in determining weight gains among adolescents. This result emphasizes that the tailored intervention is strongly warranted, in particular among boys residing in urban area.

The Health Effects of Asian Dust Event

The Korean peninsula has a long history of spring time dust clouds blown by winds from the arid deserts of Mongolia and China, these are called Yellow sand or Asian dust event. Public concern about the possible adverse effects of these dust events has increased, because the dust arrives in Korea after having passed over heavily industrialized eastern China. Most studies on the Asian dust have been focused on the physiochemical properties of the dust. Just several studies have been published on the matter of the health effects of the Asian dust both domestically and internationally. Even though the dust of crustal origin like the Asian dust is not considered as harmful as the dust from the exhaust gas, many people have experienced the eye symptoms and the respiratory symptoms such as cough, sputum, and chest tightness during the yellow sand period. However it is not clear that the increased risk of experiencing respiratory symptoms during the dust period leads to increased risk of hospitalization or mortality. Limited epidemiologic studies suggest that the aged people and the patients with cardiopulmonary disease are more susceptible to possible harmful effects of the Asian dust.

Guidelines for Work-related Diseases

The purpose of the Industrial Accident Compensation Insurance Act is to compensate any occupational accident of workers in a rapid and fair manner. To reduce theburden of proof of causation, there is a way to establish presumptive standards such as 'Guidelines for Work-related Diseases'. A presumptive standard defines a level of evidence sufficient to demonstrate legally a causal relationship between occupation and disease. In Korea, 24 items including physical agents, chemical agents, biological agents and some diseases are enlisted as work-related diseases.

Chromosomal gains and losses in primary ovarian carcinomas by comparative genomic hybridization / 대한산부인과학회잡지

OBJECTIVE: Comparative genomic hybridization was performed to evaluate DNA sequence copy number changes in human ovarian carcinomas from paraffin-embedded tissue blocks. PATIENTS AND METHODS: DNA from 20 cases of primary ovarian carcinomas underwent comparative genomic hybridization to evaluate the extent of genetic gains or losses in a test sample. RESULTS: In thirteen cases of 20 samples, varying degree of genetic imbalances was observed. Of the remaining 7 cases, two revealed normal, five failed to yield a result. Most common genetic imbalances are 8q22.2-q24 site amplification and 12p site amplification, where c-myc gene and k-ras gene respectively are included. Second most common site of genetic imbalance is 7p21-pter site deletion. CONCLUSION: Our results have shown many chromosomal alterations in human ovarian carcinomas, and these sites are known previously as oncogene or tumor-suppression gene, and some sites are not known specific cancer associated sites. Our data can be useful for screening chromosomal changes and molecular mechanism of human ovarian carcinogenesis.

The Association of Subjective Stress, Urinary Catecholamine Concentrations and PC Game Room Use and Musculoskeletal Disorders of the Upper Limbs in Young Male Koreans

The use of PCs can cause health problems, including musculoskeletal disorders (MSDs) of the upper limbs. This study was performed to investigate whether using PCs in PC game rooms may induce MSDs of the upper limbs. 284 young male Koreans were included. A self-administered, structured questionnaire was used to gather information about game room use, perceived subjective stress, and the symptoms related to MSDs. Urinary concentrations of epinephrine, norepinephrine, and dopamine were measured in spot urine. The symptom prevalence of MSDs of the upper limbs increased according to the increase of the duration of game room use. The intensity of perceived subjective stress showed a significant dose-response relationship with the frequency of MSDs symptoms in neck and shoulder areas. However, the urinary level of catecholamines was not significantly correlated with the symptom prevalence of MSDs in the upper limbs. These findings suggest that using PCs in game rooms produce physical stress on the upper limbs, strong enough to induce MSDs.

Perceptions of the Asian Dust: Analysis of the Newspaper Articles about the Asian Dust / 예방의학회지

OBJECTIVES: There is an increasing concern for the social, economic, environmental and health effects of the Asian dust (Hwang-sa in Korean language) in Korea. In this study, we intended to indirectly determine ordinary people's perception about the Asian dust by analyzing the contents of newspaper articles dealing with it. METHODS: By using article searching services in the internet websites of three newspaper companies, we collected newspaper articles dealing with the Asian dust during the period from January 1st of 1998 to December 31st of 2002. We classified the articles into four categories: those forecasting the occurrence of the Asian dust, those about measures to cope with it, those about its occurrence in the neighboring foreign countries, and those about its effects. In particular, we analyzed articles about the health effects of the Asian dust more distinctly. RESULTS: A total of 1, 225 articles dealing with the Asian dust were found during the 5 year period. The number of articles increased from 102 in 1998 to 518 in 2002, approximately a five-fold increase. The numbers of articles about health effects, environmental effects and economical effects were 191 (44%), 171 (41%) and 147 (34%), respectively. It was reported that various diseases such as respiratory diseases (87%), eye problems (69%), and skin diseases (12%) were associated with the Asian dust. CONCLUSION: The increasing concern for the negative effects of the Asian dust necessitates more studies about this field. As the effects of the Asian dust are various, the information on the major concern of ordinary people could help establish the research agendas and measures for the Asian dust.

Importance of job demands, career development, role pressure, and economic-issue-related job stress as risk factors for work related musculoskeletal disorders in electronics assembly line workers / 대한산업의학회지

OBJECTIVES: To evaluate the association of upper extremity musculoskeletal disorders with job demand-control and effort-reward related job stress. METHODS: Questionnaires concerning symptoms, psychosocial factors and work conditions were completed by 436 workers from a refrigerator assembly line, mobile phone assembly line, and an office, musculoskeletal conditions of the upper extremities were defined by the frequency, duration, and intensity of symptoms. A walk-through survey was performed to evaluate various physical work factors. Data were analyzed with the use of logistic regression. RESULTS: A total of 382 workers completed the survey, for whom neck and shoulder symptoms were the most frequently reported, followed by finger and wrist, and then elbow symptoms. Both awkward working posture and forceful exertion were associated with an increase in shoulder/neck and finger/wrist symptoms. In addition, job stress factors such as monotony, low job clarity, low job control, low promotion prospect, economic issues, and retirement pressures were associated with increased neck/shoulder, elbow, and finger/wrist conditions. Women were more likely to report symptoms, and the association between musculoskeletal conditions and job stress factors was stronger in female assembly line workers and office workers than in male assembly line workers. CONCLUSIONS: The results suggest that musculoskeletal conditions of the upper extremities are associated with not only physical work factors but also job stress factors. In particular, economic issues and career development factors are important influences on workers in Korea.

The Correlation Between the Expression of CD44 Variant 6 Molecule and the Prognostic Factors in Early Stage Cervical Cancer / 대한산부인과학회잡지

OBJECTIVE: CD44 (Cluster Differentiation 44) is an adhesional molecule postulated to play a role in tumor-cell invasion and metastasis. We have evaluated the correlation between the expression of CD44 variant 6 molecule and the prognostic factors in early stage cervical cancer. METHODS: Total sixty five samples of cervical tumor (23 samples of carcinoma in situ, 19 samples of FIGO stage Ia1, 9 samples of stage Ia2, 15 samples of stage Ib1) were immunohistochemically stained for detecting CD44V6 molecule, and which were compared with FIGO stage, invasion depth, gland involvement, lymphovascular space invasion, and keratinized type. RESULTS: CD44V6 was detected in 60 cases (92.3%). Immunoreactivity was decreased in more than 5 mm stromal invasion depth group (p=0.009), and there were no difference in carcinoma in situ, stage Ia1, and stage Ia2. There were no correlation between the expression of CD44 variant 6 molecule and the FIGO stage, gland involvement, lymphovascular space invasion, and keratinized type. CONCLUSION: CD44V6 expression does correlate with early stromal invasion, but does not correlate with other prognostic factors in cervical cancer. CD44V6 expression may play important role in progression of early cervical cancer.

The Desk Height and Keyboard Design as Determinants of Posture and Trapezius Tension

OBJECTIVE: To test the hypothesis that changing the desk height or keyboard design with fixed neck posture will change posture of the upper extremity and the trapezius tension, and to suggest the appropriate the desk height and the keyboard design to relieve the tension of the trapezius. METHOD: Five men volunteered. Four desk heights (5 cm below, same as, 5 cm above, 10 cm above the olecranon) and three keyboard designs (flat, wrist support, natural) were set up. The posture of the upper extremity was analysed by 3 dimensional Ariel performance analysis system. The tension of trapezius was measured by surface EMG. RESULTS: The trapezius tension was low when the desk height was below the olecranon in 'flat' keyboard, and was low when the desk height was no higher than 5 cm above the olecranon in 'wrist support' and 'natural' keyboard. The trapezius tension went with the change of the shoulder flexion, abduction, elevation and the elbow flexion in 'flat' keyboard, and went with the change of the shoulder flexion and elevation in 'wrist support' and 'natural' keyboard. CONCLUSION: To lessen the tension of the trapezius, the desk height should be below the olecranon in 'flat' keyboard and no higher than 5 cm above the olecranon in 'wrist support' and 'natural' keyboard. The keyboard design should include the wrist support which relieved the tension of trapezius by giving the resting point.

The Effects of Job Stress on the Autonomic Nerve Activity of Workers in Manufacturing Industry / 대한산업의학회지

OBJECTIVE: A cross-sectional study was conducted to evaluate the relationships between autonomic nerve activity (i.e., heart rate variability and urinary catecholamines) and job stress. METHODS: The study was conducted on 134 workers from a company producing consumer goods (i.e., diaper, paper towel) located in Cheonan, Korea. Job stress was assessed by Karasek's Job Content Questionnaire (JCQ). Autonomic function was assessed by heart rate variability (HRV) and urinary catecholamines (epinephrine, norepinephrine, and dopamine). Urine samplings, and measurings of HRV, were repeated three times for each shift. Information on demographic characteristics, previous job histories, past medical history, smoking and drinking were also collected. RESULTS: No statistically significant differences were observed in any HRV and urinary catecholamines among the four groups, which were categorized by the Job Strain Model. When data were stratified by work duration, low field HRV was borderline significantly higher in the high strain group in individuals with a shorter work duration (<48.5 months, N=28, p-value of 0.92 by analysis of variance). CONCLUSIONS: Neither HRV nor urinary catecholamines are significantly associated with job stress, as assessed by the Karasek's JCQ. However, HRV seems to be a potential physiological indicator of job stress only in the workers with a shorter work duration.