Incidence and Risk Factors for Occupational Low Back Pain Among Shipyard Workers / 대한산업의학회지

OBJECTIVES: This study was conducted to estimate the incidence rate, and to identify the risk factors for the occupational low back pain among shipyard workers. METHODS: The study subjects consisted of 9,784 workers who were employed in a ship-building industry(excluded workers who had a history of low pack pain before 1995 or did not take periodic health examination in 1995). The cases were 220 people who experienced back pain from January 1, 1996 to December 31, 1998. To assess risk factors for occupational low back pain, Cox propotional hazard model was used. RESULTS: During the recent three years from 1996 to 1998, the incidence rate per 1,000 persons was 7. 8 in 1996, 8. 8 in 1997, and 3. 1 in 1998. The main causes of work-related low back pain were sprain, strain and disc herniation. Lifting was the most common cause of back pain(35. 3%), and carrying(10.2%) and pulling(8.0%) were followed. In Cox proportional harzard model, independent risk factors for back pain were body mass index(R.R.; 1.54, 959o C.I.: 1.06-2.25), shift work(R.R.; 1.65, 95% C.I.: 1.19-2.28), and lifting heavy material(R.R. ; 3.95, 95% C.I: 2.29-6.82). CONCLUSIONS: This study suggests that the risk factors of back pain in shipyard workers were body mass index, shift work and lifting.

CYP2E1 Genetic Polymorphism relating to Styrene Metabolism of Korean Workers / 대한산업의학회지

The goal of this study is to observe the associations between the metabolic phenotype by personal exposure and urinary metabolites and genetic polymorphism of CYP2E1 which is known to be related with styrene metabolism. To complete this study, the author executed a battery of tests on 46 workers who were working at laminating department of fiberglass- reinforced plastics (FRP) industry located in Pusan and Kyungnam area during April to June 1998. Those were - (1) personal exposure assessment with organic vapour monitor and gas chromatography. (2) measurement of urinary metabolites - mandelic acid (MA) and phenylglyoxylic acid (PGA) - with high performance liquid chromatography (HIPLC), (3) CYP2E1 genotying with PCR and restriction fragment length polymorphism (RFLP) using Dra I and Rsa I, and (4) questionnaire survey for some individual characteristics. Study subjects were composed of 32 men and 14 women, and whose average age was 39.4 years, average tenure was 7.7 years. Each concentration expressed by geometric mean(range) was as follows; air styrene 15.6(3.1-81.0) ppm, urinary MA 187.8(36.8-1007.2) mg/g creatinine, PGA 232.8(46.8-1075.7) mg/g creatinine. Correlation coefficients between air styrene were MA 0.54, PGA 0.37, MA+PGA 0.54 (p or= 0.063 and air styreneTLV-TWA/urinary MA+PGABEI >or= 0.048 was classified as poor metabolizer, and, the value of air styreneTLV-TWA/urinary MABEI~ 0.05), as in case of MA, mutant type 66.7% and wild type 48.0%, and in case of MA+PGA, mutant type 81.0% and wild type 56.0%. These results suggests that CYP2E1 mutant allele has a tendency toward the poor metabolizer. This study has several limitations as small sample size, and no considerations on work intensity, alcohol habit, obesity, etc which can affect styrene metabolism. However, this study is of value because this is first study to propose the fundamental data about associations between exposure level, biological monitoring, and CYP2E1 genetic polymorphism in Korean workers dealing with pure styrene. To improve accuracy of the study, that means, to applicate the result of this study on the personal risk assessment of styrene workers, larger sample size and consideration for confounders are needed.

The Significance of Increased Signal Intensity in MR Imaging among Male Welders / 대한산업의학회지

A purpose of present study is to provide basic information evaluating the utility of Magnetic Resonance imaging as a biological marker estimating manganese effects to central nervous system among welders, which is conducted by comparing urinary and blood manganese concentrations and signal intensities of brain MR images between exposed group and non-exposed group, evaluating the objectivity of subjective grading estimated by correlations between Pallidal signal intensity index (P. I) and subjective grades among exposed group, and comparing the difference of signal intensities according to presence of neurologic symptoms, signs and exposure variables among the exposed group. The exposed group is composed of 11 welders complaining severe symptoms or showing neurological signs, and the non-exposed group is composed of 5 patients who admitted a hospital. Urinary manganese concentrations and signal intensities in T1-weighted MR images among exposed group were higher than those of the non-exposed group significantly, which exhibits that increased signal intensities in T1-weighted MR image represent the effect of manganese exposure. P. Is among the exposed group revealed relatively high correlations with subjective grades ( gamma =0.63, p=0.037) , which suggests the objectivity of subjective grade. Signal intensity in globus pallidus was a suitable single variable representing the effect of manganese accumulation in C.N.S system appropriately, which was verified as follows ; Increased signal intensities among the exposed group had the highest frequency and intensity in the globus pallidus, and the P.I. had a relatively high correlation coefficient ( gamma 0.62, p=0.044) with total score of subjective grades. Signal intensity with subjective grading in globus pallidus represented very high correlation gamma =0.97, p=0.00) with total score of subjective grades, and had a similar correlation coefficient with many variables. It is hard to argue that signal intensities are markers representing pathologic change in C.N.S system or can be used as a diagnostic tool for manganese intoxication, because signal intensities had no difference between the exposed group and the non-exposed group according to presence of neurological signs.

PCR and RFLP-based CYP2D6(B) and CYP2D6(T) Genotyping for Korean Lung Cancer Cases and Controls / 예방의학회지

The genetically determined CYP2D6 activity is considered to be associated with cancer susceptibility with inter-individual variation. Genetic polymorphism of CYP2D6(B) and CYP2D6(T) was determined by the two polymerase chain reaction(PCR) and BstN1 and EcoN1 restriction fragment length polymorphisms(RFLP) for 67 lung cancer cases and 95 healthy volunteer controls. The cases were composed of 26 squamous cell carcinoma, 14 small cell carcinoma, 10 adenocarcinoma, 3 large cell undifferentiated carcinoma, and 14 not histologically diagnosed. The results were gained from the 142 subjects (57 cases and 85 controls) who observed successfully in two PCR and BstN1/EcoN1 RFLP. Only one and no mutant allele of the CYP2D6(B) and CYP2D6(T) gene was detected, that is, the frequency of mutant allele was very low; 0.7%(1/142) and 0%(0/142), respectively. Detected mutant allele of the CYP2D6(B) was heterozygous type(WM). The odds ratios for lung cancer susceptibility with CYP2D6(B) and CYP2D6(T) genotype were not calculated. These results are similar to the previous understanding that the mutant allele is very rare in Orientals compared to Caucasians, therefore, it considered that CYP2D6(B) and CYP2D6(T) genotypes have maybe no association with lung cancer susceptibility in Koreans. This is the basic data of CYP2D6(B) and CYP2D6(T) genotypes for Koreans. It would be hepful for further study to determine lung cancer susceptibility of Koreans with the data about CYP1A1, CYP2E1, GSTM1 from future study.

Relationship of Level of Stress, Life Style, Subjective Symptoms and Clinical Diagnosis in Clients taken Multiphasic Screening Program / 예방의학회지

To improve wellness and quality of life by recognizing the health effects of stress, the author estimated the relationships between stress, subjective symptoms and clinical diagnosis through a questionnaire and a battery of specified laboratory tests - electrocardiography, blood pressure, cholesterol, aspartate aminotransferase(AST), alanine aminotransferase(ALT), gamma glutamyl transferase(gamma-GTP), fasting blood sugar, gastro-endoscopy or UGI, abdominal sonography, etc. The data was gathered from 337 clients who were undergoing multiphasic screening program at a University Hospital from January to March 1998. The mean age of subjects was 46.5+/-11.2 years and the mean of body mass index was 24.0+/-3.7kg/m2. The mean level of stress was 18.5+/-6.0 expressed as the score out of 40. By general characteristics and life style among male, mean level of stress was significantly higher in case of lower socioeconomic status, habitual drug use, longer daily working time(>10 hours), no regular exercise, drinkers, irregular meal, skipping breakfast(p10 hours), no regular exercise, drinkers, smokers, irregular meal, skipping breakfast(p<0.05). Significant correlations were observed between stress and subjective symptoms in all kinds of organ system(p<0.01). Correlation coefficients of stress among male were relatively high with neuro-psychiatric symptom(gamma=0.476) and cardio-vascular symptom(gamma=0.361) in order, and correlation coefficients of stress among female was highest with neuro-psychiatric symptom(gamma=0.371). The prevalence of the diagnosis through the battery of laboratory tests was high in upper gastrointestinal disorders and hypercholesterolemia in order in both sex group. Among male the mean score of stress was significantly high in ulcerative peptic disorder of upper gastrointestine and hepatopathy in order (p<0.05) . Among female that was significantly high in diabetes mellitus. In summary, it is likely that there are associations between stress, subjective symptoms and clinical diagnosis. To promote wellness and quality of life through, therefore, it would be of value that periodic stress evaluation program and stress management including appropriate control of smoking and drinking, regular exercise and meal.

The Knowledge and Practice of the Breast Self-examination in Women who got health check up / 예방의학회지

The methods for the early diagnoses of breast cancer are mammography, physical examination, breast self-examination(BSE). This study was conducted to investigate the knowledge and practice of BSE by structured questionnaire which included questions on general characteristics, performance of mammography, physical examination of breast, knowledge and practice of BSE. The subjects in this study were 412 females between 20 and 69 years old who visit to the Health Care Center of College of medicine of Inje University from December 1997 to February 1998. The results were as follows: 1. Women who have gotten the regular mammography are 8.19% of these subjects and women who have gotten the regular physical examination by doctors are 4.19% of these subjects. 2. Regarding BSE, 77.4% of these subjects said that they knew BSE and 3.88% of these subjects said that they practiced BSE regularly. It was that women who knew BSE were more younger, better-educated and higher economic status(p=0.001) and lived a normal life with her husband(p=0.033). And women who practiced BSE regularly were more younger, and married(p=0.001). 3. The most common barrier to doing BSE is 'Do not see the needs/Worry unnecessarily', and the most common reasons for doing BSE is 'Early detection'. 4. The overall frequency and percentage distribution of recommended BSE step in Korea is lower than U.S.A.

Relating Factors of Industrial Accident / 대한산업의학회지

This study was conducted to estimate the causing factors of industrial accident, and to prepare the fittable control program for accident through the evaluation of views of the patients who suffered from accidents. From January 5 to February 6 1993, questionnaire survey was executed on 166 persons who were injured and covered by the insurance under industrial accident compensation law at four university hospitals in Pusan. The results were as follows : 1. Most of subjects worked in the manufacturing (56.6%) and construction(29.5%), and in the small factory less than 49 workers(56.0%). They were thirties and forties(63.8%), less than 3 years tenure(53.6%), habitual drinker(69.2%). And, 72.3% worked for above 9 hours per day, 53.6% worked as near clerks, 89.2% thought that work is rather suitable to his own personality. 2. Self-recognition for the causing factor of industrial accident was the other's malfunction(19.3%), carelessness(15.1%), lack of education for safety(15.1%), and they thought the accident occurred by mainly some defect of establishment and working environment(34.9%), unskillfulness(22.9%), self-carelessness(22.3%). 3. The interests and recognition on safety was insufficient, 88.6% require job education, but 53% pointed out the necessity for strengthening of present status-rather incomplete with relying on self-education (40.9%), no previous participation in safety education (29.5%), etc. 4. For the kind of accident, fall-down(16.3%), crash(13.3%), falling(12.7%) was frequent, head(24.7%) and fracture(41.0%) was frequent for the part and type of injury, respectively. And, they had more injured by cooperative work (82.5%) than single work. As results, improvement of working environment and strengthening education program would be emphasized for the effective control of industrial accident. And, there should be prepared the specific prevention program for the small scale industries.

Urinary Metabolites and Neurobehavioral Test on Styrene Exposure Workers / 예방의학회지

In order to prepare the fundamental data for the health promotion by assessing the exposure level of styrene, the author determined the concentration of mandelic acid and phenylglyoxylic acid in urine of 42 workers who were exposed to styrene by high performance liquid chromatography and surveyed 16 symptoms, by questionnaire and also tested neurobehavioral test(digit symbol, benton visual retention) in 2 FRP plants of Kyung Nam area from July to September, 1995. Control was sampled by age sex matching method. The concentration of styrene in air was determined by gas chromatography. The results were as follows; 1. Geometric mean concentration of styrene in air was 17.4ppm, geometric mean concentration of mandelic acid(MA) in urine were 404.3mg/g creatinine for exposure group, 46.4mg/g creatinine for control group, geometric mean concentration of phenylglyoxylic acid(PGA) in urine were 57.5mg/g creatinine for exposure group, 9.5mg/g creatinine for control group. Mean concentration of MA and PGA showed statistically significant difference between exposure group and control group(p<0.01). 2. Number of symptom were 2.9 for exposure group, 3.3 for control group, number of digit symbol were 24.1 for exposure group, 32.5 for control group, number of Benton visual retention test were 6.1 for exposure group, 6.0 for control group, respectively. As result of adjusting the education year, number of Benton visual retention test showed statistically significant difference between exposure group and control group(p<0.05). 3. Excellent correlation were observed between environmental styrene exposure and urinary MA(r=0.80), PGA(r=0.73), and MA+PGA(r=0.81).