• Journal of Radiation Protection and Research
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• v.40 no.3
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• pp.124-131
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• 2015

Radiation exposure to humans can be caused by the gamma rays emitted from natural radioactive elements(such as uranium, thorium and potassium and any of their decay products) of Naturally Occurring Radioactive Materials(NORM) or Technologically Enhanced Naturally Occurring Radioactive Materials(TENORM) added consumer products. In this study, assume that activity of radioactive elements is $^{238}U$, $^{235}U$, $^{232}Th$ $1Bq{\cdot}g^{-1}$, $^{40}K$ $10Bq{\cdot}g^{-1}$ and the gamma rays emitted from these natural radioactive elements radioactive equilibrium state. In this study, reflected End-User circumstances and evaluated annual exposure dose for products based on ICRP reference voxel phantoms and ICRP Recommendation 103 using the Monte Carlo Method. The consumer products classified according to the adhere to the skin(bracelet, necklace, belt-wrist, belt-ankle, belt-knee, moxa stone) or not(gypsum board, anion wallpaper, anion paint), and Geometric Modeling was reflected in Republic of Korea "Residential Living Trend-distributions and Design Guidelines For Common Types of Household.", was designed the Room model($3m{\times}4m{\times}2.8m$, a closed room, conservatively) and the ICRP reference phantom's 3D segmentation and modeling. The end-user's usage time assume that "Development and Application of Korean Exposure Factors." or conservatively 24 hours; in case of unknown. In this study, the results of the effective dose were 0.00003 ~ 0.47636 mSv per year and were confirmed the meaning of necessary for geometric modeling to ICRP reference phantoms through the equivalent dose rate of belt products.

• Sleep Medicine and Psychophysiology
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• v.9 no.1
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• pp.41-47
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• 2002

Objectives: In a number of simulated night shift studies, timed exposure to bright light improves sleep quality and work performance. We evaluated the effect of bright light on adaptation to night shift work with a field study. Methods: Five female nurses working shifts at Korea University Hospital were recruited for participation in this study. We investigated two series of six consecutive shift rotations comprising three day and three night shifts, using wrist Actigraphy, the Stanford Sleepiness Scale, Visual-analogue scales, STIM and tympanic membrane temperature for daytime sleep quality, alertness, subjective feeling, attention performance, and temperature rhythm. The subjects were exposed to bright light (2,500 lux) from 24:00 to 04:00 a.m. on three consecutive night shifts during the second series, whereas they worked under normal lightening (650 lux) conditions during the first series. Results: Actigraphic assessment of daytime sleep showed no significant difference between the first and third night shift in both baseline and light exposure phase. The mean lowest temperature shifted earlier during baseline phase but not during the light exposure phase. Also, the score for subjective feelings of depression, anxiety, physical discomfort and sleepiness was significantly higher in the third night shift than the first during baseline phase but not during the light exposure phase. Attention and attention switching ability was significantly improved in the third night shift compared to the first night during the light exposure phase but there were no significant changes during the baseline phase. Conclusion: This result suggests that there were no significant differences between the two phases in measures of quality of daytime sleep, but subjective feelings, attention and alertness were enhanced during light exposure. Although some placebo effects and learning effects might influence this result, bright light exposure between midnight and 4:00 a.m. may improve adaptation to night shift. In future, further controlled studies with a larger sample size, including melatonin measurement, are needed for real shift workers.

• Journal of the Ergonomics Society of Korea
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• v.36 no.3
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• pp.183-196
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• 2017

Objective: The purpose of this research was to assess the agreement between job physical risk factor analysis by ergonomists using ergonomic methods and physical examinations made by occupational physicians on the presence of musculoskeletal disorders of the upper extremities. Background: Ergonomics is the systematic application of principles concerned with the design of devices and working conditions for enhancing human capabilities and optimizing working and living conditions. Proper ergonomic design is necessary to prevent injuries and physical and emotional stress. The major types of ergonomic injuries and incidents are cumulative trauma disorders (CTDs), acute strains, sprains, and system failures. Minimization of use of excessive force and awkward postures can help to prevent such injuries Method: Initial data were collected as part of a larger study by the University of Utah Ergonomics and Safety program field data collection teams and medical data collection teams from the Rocky Mountain Center for Occupational and Environmental Health (RMCOEH). Subjects included 173 male and female workers, 83 at Beehive Clothing (a clothing plant), 74 at Autoliv (a plant making air bags for vehicles), and 16 at Deseret Meat (a meat-processing plant). Posture and effort levels were analyzed using a software program developed at the University of Utah (Utah Ergonomic Analysis Tool). The Ergonomic Epicondylitis Model (EEM) was developed to assess the risk of epicondylitis from observable job physical factors. The model considers five job risk factors: (1) intensity of exertion, (2) forearm rotation, (3) wrist posture, (4) elbow compression, and (5) speed of work. Qualitative ratings of these physical factors were determined during video analysis. Personal variables were also investigated to study their relationship with epicondylitis. Logistic regression models were used to determine the association between risk factors and symptoms of epicondyle pain. Results: Results of this study indicate that gender, smoking status, and BMI do have an effect on the risk of epicondylitis but there is not a statistically significant relationship between EEM and epicondylitis. Conclusion: This research studied the relationship between an Ergonomic Epicondylitis Model (EEM) and the occurrence of epicondylitis. The model was not predictive for epicondylitis. However, it is clear that epicondylitis was associated with some individual risk factors such as smoking status, gender, and BMI. Based on the results, future research may discover risk factors that seem to increase the risk of epicondylitis. Application: Although this research used a combination of questionnaire, ergonomic job analysis, and medical job analysis to specifically verify risk factors related to epicondylitis, there are limitations. This research did not have a very large sample size because only 173 subjects were available for this study. Also, it was conducted in only 3 facilities, a plant making air bags for vehicles, a meat-processing plant, and a clothing plant in Utah. If working conditions in other kinds of facilities are considered, results may improve. Therefore, future research should perform analysis with additional subjects in different kinds of facilities. Repetition and duration of a task were not considered as risk factors in this research. These two factors could be associated with epicondylitis so it could be important to include these factors in future research. Psychosocial data and workplace conditions (e.g., low temperature) were also noted during data collection, and could be used to further study the prevalence of epicondylitis. Univariate analysis methods could be used for each variable of EEM. This research was performed using multivariate analysis. Therefore, it was difficult to recognize the different effect of each variable. Basically, the difference between univariate and multivariate analysis is that univariate analysis deals with one predictor variable at a time, whereas multivariate analysis deals with multiple predictor variables combined in a predetermined manner. The univariate analysis could show how each variable is associated with epicondyle pain. This may allow more appropriate weighting factors to be determined and therefore improve the performance of the EEM.

• Journal of radiological science and technology
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• v.31 no.3
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• pp.239-247
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• 2008

In order to study the occurrence of symptoms of musculoskeletal disorders of radio-technologists employed at metropolitan general hospitals and the factors that influence such occurrence, standardized questionnaire by NIOSH that was modified and supplemented to be suitable for conditions in Korea was used. Answers collected from 143 radio-technologists in two weeks from June 13, 2007 were analyzed and the results are as follows. Factor that influence symptoms of musculoskeletal disorders by area were analyzed through multiple logistic regression analysis and the results found that in the neck area, risk increased as the burdening work category 2(Korea ministry of labor)(OR=3.94) and burdening work category 9(Korea ministry of labor)(OR=4.72) increased. In the shoulder region, risk increased as burdening work category 2(Korea ministry of labor)(OR=5.36), burdening work category 7(Korea ministry of labor)(OR=3.90), and burdening work category 9 (Korea ministry of labor)(OR=5.76) increased. In the arm/hand/wrist regions, risk increased as burdening work category 2 (Korea ministry of labor) (OR=6.91), and burdening work category 9 (Korea ministry of labor)(OR=3.76) increased. In the lower back region, risk increased as burdening work category 2 (Korea ministry of labor) (OR=3.06), and burdening work category 8 (Korea ministry of labor)(OR=8.14) increased. In the leg/knees/foot regions, risk increased as burdening work category 2 (Korea ministry of labor) (OR=3.63), and burdening work category 9 (Korea ministry of labor)(OR=2.96) increased. Conclusively, in factors that influence musculoskeletal disorder symptoms in radio-technologists, influence of subjective health conditions, total work experience, experience in current division, and burdening work category 2, 7, 8, and 9 (Korea ministry of labor) were most significant. Therefore, for preventive management, in addition to ergonomic and educational intervention for correcting improper posture during work, efforts for break time adjustment and stress reduction is needed, and encouragement and support for regular exercise is needed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.4
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• pp.289-299
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• 2007

Objectives : To investigate the related factors on musculoskeletal symptoms among Korean female workers. Methods : A total of 1,875 female workers (1,002 office workers and 873 blue-collar workers) was analyzed. They were randomly selected among female workers by cluster sampling and interviewed by well trained interviewer, who filled out a structured questionnaire on the musculoskeletal symptoms. Other factors such as general and occupational characteristics including workplace location, employment condition, work duration, and working condition were also investigated. Results : Current smokers and drinkers were significantly more common in blue-collar workers than in office workers. Those working full time were significantly more common in blue-collar workers than in office workers. Those working over 8 hours per day were also popular in office workers than in blue-collar workers. Subjective musculoskeletal symptoms were significantly higher in the type of work including excessive repetitive work, work using awkward stretching hand upwards, work using repetitive wrist movements, static work using awkward hand posture, and heavy manual lifting and handling works. The mean score of the symptoms were significantly higher in blue-collar than in office workers. The significantly different working factors between two groups were work duration, employment condition and daily work hours. Conclusion : We suggest that the type of work including awkward and repetitive works as well as job type may be one of the most important factors related to musculoskeletal symptoms of female workers in the workplace. Preventive strategy will be needed to prevent the negative impact on health status of working women in the workplace.

• Journal of forensic and investigative science
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• v.2 no.1
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• pp.5-22
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• 2007

From the numerous social problems generated by the unbalanced social development and the social trend of belittling life overall, we found the causes of suicide getting worse in its seriousness day by day. In reality, the problem has been approached in a collateral level in contrast with other social problems. There have been an active involvement in studying the definition, causes and ways of prevention of suicide theoretically until now. However, different from other social problems, it is almost impossible to treat or fix the problem of suicide. Only ways to treat or fix the problem is when the suicide has ended in failure. Thus, this study intends to examine the suicide rate among the total accidents during the year 2005, perform the analyses on the actual causes according to the relations such as the means of suicide, occupation, age group, educational background, etc. In order to present a solution to the issue of suicide becoming serious each day. Among the total accidents in 2005, the suicide rate came out to be approximately 52.4%. Among the result, 52.4%, male with 69% resulted higher than female with 31%, which appears to be related to the social functions. While men tends to take more active(80%) means of suicide like jumping off, poison, hanging, etc., women tends to take more passive(60%) means of suicide like sleeping pills, slitting wrist, etc. In terms of the cause, pessimism, illness, denial, mental disorder, etc resulted more than 75%, and there were many cases of suicide after exhibiting the signs of depression. Also there were higher suicide rate of the unemployed engaged in direct labor with educational background lower than college level related to the pessimism regarding the family living cost. We were able to determine the recent increase in the suicidal tendency of the educated people higher than the college level and the retired people with depression caused by the sudden change in social status. Overall there are several reasons for suicide, however, in most cases the signs of depression were exhibited until the final suicide, which tells us the serious psychological problem of suicide. Assuming that the current development of suicide will continue in future, the result of this study will guide the corresponding social policies, be utilized in preparing the insurance or management at the national level dealing with the real social problems that are not just a conflict of an individual, but could spread like a fad and become much bigger than the present by the continuous support at the environmental, social and political levels, and be utilized as the basic data to establish the research plan.

• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.152-157
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• 2010

Purpose : Vitamin D deficiency rickets is a significant public health problem that results from insufficient exposure to sunlight and inadequate vitamin D supplementation. The purpose of this study is to identify the clinical characteristics of vitamin D deficiency rickets in infants. Methods : Data of 35 infants diagnosed as vitamin D deficiency rickets at Sanggye-Paik Hospital, Seoul, Korea, from March 2007 to May 2009 were reviewed. Children with plasma 25-hydroxyvitamin D levels <15 ng/mL and 15-30 ng/mL were considered to have vitamin D deficiency and vitamin D insufficiency, respectively. Results : Thirty-five infants (22 boys, 13 girls) were diagnosed with rickets. Mean age at diagnosis was $7.4{\pm}7.1$ months (range: 0.1-29.8 months). Eighteen infants (51%) were vitamin D deficient and seventeen infants (49%) were insufficient. Twenty-eight of all (80%) diagnosed as subclinical rickets. Twenty-nine infants (83%) were below the age of 12months. Twenty infants (57%) had breastfed and ten infants (29%) had iron deficiency anemia. Nine of breastfed infants (45%) were vitamin D deficient and ten of their mothers were vitamin D insufficient. Overall, radiographic evidence of rickets was present in 93% of the cases. Radiographic sign of rickets was evident even in vitamin D insufficient state. Conclusion : It is important for the clinician to screen for subclinical vitamin D deficiency rickets in inadequately supplemented infants by pairing 25-hydroxyvitamin D levels with wrist radiographs. A nationwide epidemiological study of vitamin D deficiency rickets must be conducted and evidence-based national guidelines must be defined to prevent rickets.

• Clinical and Experimental Pediatrics
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• v.52 no.3
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• pp.351-355
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• 2009

Purpose : This study compared bone ages measured by the Greulich-Pyle (GP) and Tanner-Whitehouse 3 (TW3) methods and investigated the differences in predicted adult heights measured by Bayley-Pinneau (BP) and TW3 methods. Methods : Bone ages were assessed from left-wrist radiographs by two investigators, one for each GP and TW3 methods in 85 normal children, 30 precocious puberty girls, and 30 constitutional growth delay boys. The differences between the measured predicted adult heights using the BP and TW3 methods were compared in each group. Results : The bone age measured by the TW3 method was less than that by the GP method in normal children. The predicted adult heights measured by the two methods showed no significant difference in normal boys, while the predicted adult height measured by the TW3 method was higher than that by the BP method for normal girls ($156.4{\pm}4.7$ cm vs. $158.9{\pm}3.8$ cm, P<0.01) and for precocious puberty girls ($156.3{\pm}4.0$ cm vs. $159.3{\pm}4.2$ cm, P<0.01). In contrast, the predicted adult height was higher from the BP method than from the TW3 method in constitutional growth delay boys ($173.3{\pm}4.4$ cm vs. $169.7{\pm}3.2$ cm, P<0.01). Conclusion : There were significant differences in predicted adult heights between the BP and TW3 method in normal girls, precocious puberty girls, or constitutional growth delay boys. In precocious puberty and constitutional growth delay, the BP method might be preferred to predict adult height, but further studies on final adult height are needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.264-273
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• 2012

This cross-sectional study was investigated musculoskeletal discomfort symptoms and related factors on some middle high school teachers. Self-questionnaire of KOSHA CODE H-30-2003 was done with 250 teachers from 1st to 15th October, 2010, the data from 231 teachers (68 male, 163 female) was statistically analyzed to search the factors related to musculoskeletal discomfort symptoms. According to NIOSH rate of musculoskeletal discomfort symptoms by body parts was 36.8%. Musculoskeletal discomfort symptoms related to age, school types, subjective health status, housekeeping time, VDT work time and regular rest. After adjusting for related variables, odds ratio (OR) of musculoskeletal discomfort symptoms was correlation significantly to subjective health status unhealthy (OR 11.75, 95% Confidence Interval, CI, 3.56-378.78). In addition, ORs (95% CI) of age (40-49) and housekeeping time (${\geq}3$) were 4.63 (1.82-26.18) and 4.33 (1.97-19.34). Analysis of the factors influencing the musculoskeletal discomfort symptoms vary in different parts of the body. The most discomfort symptoms by parts was neck (26.0%) and shoulder (30.0%). In the neck region was related to subjective health status and regular rest. In the shoulder and waist region was subjective health status and sex. Age was wrist/finger, leg/foot was related to subjective health status, sex and VDT work time. Age, school types, subjective health status, housekeeping time, VDT work time and regular rest related to musculoskeletal discomfort symptoms and the most discomfort symptoms by parts was neck and shoulder.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.2
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• pp.163-167
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• 2003

Purpose: The purpose of this study is to describe causes and injury mechanisms during inline skating and to find preventive measures .Materials and Methods: We have carefully selected 57 patients who have been treated in our hospital and nearby hospital. There are 37 males and 20 females, and mean age is 9 years 9 months (range,6-40 years old) . We have meticulously investigated their injured sites, their favorite location for inline skating , their use of protective means while they were on the wheels and their injury mechanisms . Results: Injury consisted of 50 fractures,1 meniscal tear,2 medial collateral ligament rupture and 4 contusion or sprain. Fracture sites varied as follows : 33(66$\%$) cases in distal radius and ulna,5(10$\%$) in elbow. 3(6$\%$) in diaphysis of humerus, etc Location at the time of injury varied as follows : 22 cases(39$\%$) in their apartment complex, 19 cases in (33$\%$) narrow streets, and 16 cases(28$\%$) in parks Only five patients admitted that any means of protection were used.2 cases only had knee pad on , 1 case put on elbow pad in addition, and 2 cases put on wrist guard as well. However none of the patients had helmet on Conclusion: We would strongly like to stress the importance of using sufficient protections and of choosing area where it is safe to ride, in order to reduce the risk of accidents. In addition, continuous and effective prior education from inline skate circles may be in order before riding the inline skate.