• 산업보건소식
• /
• no.46
• /
• pp.3-13
• /
• 1987

For the purpose of investigating the effect of occupational health service in terms of environmental control and health provision of workers on the improvement of worker's health, authors analysed the data of environmental measurement and health check-up of one lead using industry who started his investment to environmental improvement from 1980. Six hundred million won was invested for environmental improvement from 1980 to 1986. This investment brought about apparent improvement of working conditions of all of the workplaces from mean concentration of lead in air over 0.15mg/$m^3$ 1981 to mean concentration of lead in air less than 0.15mg/$m^3$. Environmental control reduced mean blood lead level from 51.2 $\pm$ 11.5ug/이 in 1983 to 39.2 $\pm$ 16.0ug/dl in 1986, and delta-aminolevulinic acid concentration 3.15 $\pm$ 2.1mg/l in 1982 to 1.96 $\pm$ 1. 7mg/l in 1986, respectively. Blood ZPP levels were decreased from 76.1 $\pm$ 58.9ug/dl in 1983 to 42.23 $\pm$ 30.3ug/dl in 1986. If 150ug/dl of blood ZPP is considered as unacceptable limit of lead intoxication, more than 10 percent of workers belonged to this category in 1983, but only 0.5 of workers showed their blood ZPP level over the 150ug/dl in 1986 It was observed that no workers whose work duration were less than one year showed their blood ZPP level over 100ug/dl, but there were high percentages of lead workers with high blood ZPP (over 150 ug/dl) who were working in uncontrolled had working condition and whose work duration were less than one year.

• Journal of Preventive Medicine and Public Health
• /
• v.22 no.3 s.27
• /
• pp.337-354
• /
• 1989

In order to evaluate the noisy environment and hearing loss of workers served in noisy working environment, the author investigated 212 manufacturing industries located in Ulsan Industrial District that could be observed for 3 successive years from 1986 to 1988. The obtained results were as follows: 1. There was increased tendency in the number of workers served in noisy working environment and that of examined of hearing loss for three years. 2. In the noise level of working environment, the number of industries less than 89dB(A) was increased every year, while more than 90dB(A) was in decreasing tendency. 3. Mean hearing loss by frequency was the most prominent in 4,000Hz, the level of hearing loss was in increasing tendency yearly, and that of left eat was higher than right ear in almost all type of industry. 4. In 1986, the level of hearing loss by type of industry was highest in manufacture of electric and electronic, and followed by paper and plywood, and metal products in right ear: that was in the order of manufacture of electric and electronic, metal products and textile products in left ear. In 1987, that was in the order of manufacture of metal products, machinery and others in right ear, and metal products, machinery and food stuff in left ear in 1988, manufacture of others, food stuff and machinery in both ear. 5. In hearing loss by service duration, right ear of 5-9 years group was higher than that of less than 5 years in 1987, whereas in 1988, the longer in service duration, the higher in the level of hearing loss in both ear. 6. In 1986, 1987 and 1988, the prevalence rate of noise-induced hearing loss were showed increasing tendency as 0.4% ,0.8% and 1.5% , respectively, and manufacture of textile products was highest(1.0%) in 1986, machinery(1.2%) in 1987 and others(2.8%) in 1988. 7. The proportion of grade E in early loss index were 76.1% (1986), 78.2% (1987) and 80.5% (1988) in left ear, 75.9% (1986), 76.4% (1987) and 75.9% (1988) in right ear.

• Journal of Preventive Medicine and Public Health
• /
• v.26 no.2 s.42
• /
• pp.282-292
• /
• 1993

Neurotoxicity in the workplace may occur with exposure to scores of chemicals. Although large acute outbreaks of the occupational neurological disease are rare, the incidence of occupational neurotoxicity in its subtler aspects is unknown. A working knowledge of both the major occupational neurotoxic solvents and the tools used by cliniical neurologists and neurotoxicologists to evaluate neurotoxicity in working populations is a necessity fur the occupational physician. To investigate the effects of carbon disulfide($CS_2$) on the peripheral nerve system using the nervous conduction study, 105 male workers working in the spinning room of a viscose rayon factory were examined and compared with a sex and age matched, unexposed 105 male controls using t-test analysis. 72.4% of $CS_2$-exposed workers complained of neurological symptoms, and the abnormal cases in nerve conduction study were 48.6%. The abnormal cases of nerve conduction study increased in number according as the age and duration of exposure increased. In this study, asymptomatic workers were confirmed to have subclinical neuropathy by nerve conduction study. Also as there were abnormal cases even in its duration of exposure below 4 years, nerve conduction study turned out to be ways of discovering of early peripheral neuropathy. In nerve conduction study, the amplitude, velocity, F-wave latency and H-reflex of the motor and sensory nerves in both upper and lower extremities were significant different between $CS_2$-exposed workers and the controls. From the pathological viewpoint, both segmental and axonal degenerations were assumed in this study.

• Journal of Korean Academy of Nursing
• /
• v.19 no.3
• /
• pp.259-272
• /
• 1989

This study was designed to measure the degree of work stress perceived by clinical nurses working in psyciatric ward, and to identify the factors influencing the difference of work stress. The survey method was used and the subjects of this study consisted of 135 psyciatric nurses from 7 university hospitals and 4 provincial general hospitals. The data were collected from August 1 to 20, 1988. The instrument used for this study was PNOSS(Psychiatric Nurse Occupational Stress Scale) which was developed by Bai(1989). The confidence verification of this instrument was computed and the Cronbach $\alpha$ was 0.94050. Data were analysed by t-test and ANOVA on 5% significant level with SPSS program. The results of study were summerized as follow : 1) The degree of perceived stress among psychiatric nurses was considerably high(4.32 out of 6.00). 2) Among the stressors, inadequate staffing(5.04), hospital administrational problems (4.7) and the conflict of nurse-patient relationship were identified as the stress factors with high rank of degree of stress. 3) There was significant relationship between the degree of stress and the demographic variables of nurses such as the marital status, educational level, and the motivation of working in psychiatric ward. 4) There was significant relationship between the job-related variables such as the working duration, the motivation of working and nurse's attitude toward the psychiatric patients. 5) The relationship between several stress factors and some of the demographic and the job-related variables were significantly identified.

• Journal of Nutrition and Health
• /
• v.39 no.7
• /
• pp.649-660
• /
• 2006

This study was performed to estimate serum 2S-hydroxyvitamin D (25-OHD) level in wintertime and to evaluate the relationship between serum 25-OHD level and associated factors in 50 premenopausal working women aged 30-49 y in Busan. The serum 25-OHD level was measured by radioimmunoassay. Data for physiological characteristics, lifestyle factors, physical activity and nutrient intake was assessed by questionnaire including information about outdoor activity time, daily activity diary and 24hr recall method. The mean vitamin D intake was $4.24{\mu}g$, which corresponded to 84.9% of the Korean RDA. The mean level of serum 25-OHD was 25.7 ng/mL. Vitamin D deficiency (25-OHD < 7nmol/L) and toxicity $(25-OHD{\geq}75\;nmol/L)$ were not found in the subjects. However, the prevalence of vitamin D insufficiency (25-OHD < 15 nmol/L) and hypovitaminosis D (25-OHD < 30 nmol/L) were 12% and 60% respectively. The serum 25-OHD level showed positive significant correlations with the duration of outdoor activity per weekdays (p < 0.05). Our findings suggest that hypovitaminosis D was common in the subjects in wintertime. So nutritional education for increasing outdoor activities is needed for premenopausal working women to increase vitamin D status in wintertime.

• Journal of the Korean Home Economics Association
• /
• v.24 no.4
• /
• pp.163-177
• /
• 1986

The purpose of this study is to present basic data of clarifying the differences between employed and unemployed wives' family and comparing low classes with other classes for the more reasonable and successful home administration through investigating and analyzing decision-making patterns of the families of working women in the low income group. The questionnaires were distributed in September 1984 to 300 working women in the city of Seoul and Sung-Nam. Statistical methods such as frequency, percentage and the mean value were used for grasping general characteristics of the families and F-test, Pearson's Correlations were used for investigating the interrelation of the related variables. The results of this study were as follows; 1) Wife's participation indecision-making was increased while joint decision-making was decreased compared with those of unemployed wives' family and other classes. 2) Both of the degree of conjugal participation in decision-making and joint decision-making were influenced by wife's educational level, disparity in educations of couple, husbands' occupation, family income, wife's age. But duration of marriage affected only the degree of joint decision-making. Especially family income and husbands; occupations turned to be important variables in low income families. 3) In case of wife's satisfaction with her occupation, joint decision-making was well achieved or not according to certain decision items. Though wife and husband satisfied with their marriage, joint decision-making was not well performed in working wives' family with low income.

• Safety and Health at Work
• /
• v.14 no.1
• /
• pp.59-65
• /
• 2023

Objectives: Epidemiological evidence linking long working hours and shift work to metabolic syndrome remains inadequate. We sought to evaluate the impact of reducing working hours on metabolic syndrome. Methods: We compared the prevalence of metabolic syndrome among male manual workers in a manufacturing company (N = 371) before and after the introduction of policy to reduce daily work hours from 10 to 8 hours. Components of metabolic syndrome were measured in periodic health examinations before the intervention, 6-9 months after, and 1.5-2 years after the intervention. Generalized estimating equation models were used to estimate changes in the prevalence of metabolic syndrome. Analyses were stratified by day work versus shift work. Results: The results showed a significantly decreased prevalence of metabolic syndrome 6-9 months following the intervention in day workers (risk ratio = 0.68, 95% confidence interval 0.52-0.88), but the benefit disappeared after 1.5-2 years. Shift workers showed a decreased prevalence of metabolic syndrome for the whole follow-up duration after the intervention, although the change was not statistically significant. Conclusion: Reducing working hours was associated with short-term improvement in metabolic syndrome in male manual workers.

• Journal of Preventive Medicine and Public Health
• /
• v.36 no.2
• /
• pp.137-146
• /
• 2003

Objectives : Impaired hearing is a prevalent occupational hazard, not only in industry, but also in the armed forces. In military life, noise has unusual characteristics, and constitutes a serious hazard to hearing. The aim of this study was to analyze the hearing threshold data in order to compare the hearing loss among shipyard workers, representing different workers, and a military service background. Methods : A cross-sectional audiological survey, combined with a questionnaire study, was conducted on a stratified random sample of 440 shipyard workers, with long-term exposure to noise. The employees were divided into four groups, according to their working and military service backgrounds, in relation to their exposure to noise. Results : As expected, the working and military noise exposure group (Group I) had significantly poorer hearing than the other groups. The high frequencies (2-8 kHz) showed the greatest difference in terms of poorer fearing in both ears. The prevalence of noise-induced hearing loss (NIHL) was highest in Group I. A logistic regression analysis was applied to determine the dependence of the NIHL in relation to age, smoking, drinking, working duration, ear protection, past history of ear diseases, and working and military sonics backgrounds, on the noise exposure The important factors found to be related to the NIHL, in relation to noise exposure were: age, work duration, and working and military service backgrounds. The adjusted odds ratio estimates for NIML in the right ear were 4.5 times greater (95% CI 1.7-11.6) for the military noise exposed group, and 7.9 times greater (95% CI 2.0-31.3) for the working noise exposed group than in the controls. The hearing thresholds at the pure-tone average and 4 kHz were significantly increased with age and work duration with both the working and military service backgrounds. Conclusions : From these results, specific preventive programs were planned, which should be assessed by epidemiological surveillance of the military noise exposed population.

• Journal of The Korean Society of Integrative Medicine
• /
• v.8 no.2
• /
• pp.131-138
• /
• 2020

Purpose : The purpose of this study was to investigate the effects of the frequency band pass filter on the P300 event-related potential in the working memory. Methods : The subjects were 20 women in their 20s who applied for participation in the experiment. Event-related potentials (ERPs) were elicited using 3-back tasks for the working memory, and were recorded from Fz, Cz, and Pz scalp electrodes. The high-pass filters were set to 0.01, 0.1, and 0.3 Hz for analysis purposes, and the low-pass filters were set to 30 and 15 Hz. The 3-back task was presented for a total of 100 times, among which 30 times were designated for the target stimulation (a matched number) and 70 times for the non-target stimulation (an unmatched number). The temporal interval between each stimulation was set at 1 second, while each time duration was randomly presented between 2 to 4 seconds. ERP were analyzed for the P300 recorded from Fz, Pz and Cz scalp electrodes. Results : Latency and amplitude had no significant interaction effects in both the high- and low-pass filters. For the main effects, the latency and amplitude of the P300 event-related potential had no significant difference in the high-pass filters, but the latency had a significant difference in the low-pass filter of Fz, and the amplitude had a significant difference in the low-pass filter of Pz. Conclusion : The results of this study showed that the less than 0.3 Hz high filters had no effects on the differences between the latency and amplitude of the P300 event-related potential in the working memory. The 30Hz low-pass filter, however, was found to be useful for recording the P300 event-related potential in the working memory.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2001.09a
• /
• pp.356-363
• /
• 2001

The friction pendulum type seismic isolation system (FPS) using the PTFE based materials has been developed to provide a simple and effective way to achieve earthquake resistance for buildings. PTFE matrials are soft and apt to be deformed easily after a few working cycles. Instead of the usual PTFE materials, the Polyimide material was used in this research. Polyimide is harder than PTFE, but has smaller friction coefficient and longer duration fur usage. In this paper, various kinds of PTFE materials were tested to define the frictional characteristics compared with the Polyimide material. FPS was manufactured with fine surface roughness and used with Polyimide material to show the seismic isolation efficiency, and life duration when applied to a rigid mass model and a 5 stole frame model.