Pilot Study for the Assessment of Work Ability of Manufacturing Workers and Managerial Workers / 예방의학회지

This study was carried out to assess work ability of manufacturing workers and managerial workers. Subjects were 446 manufacturing workers and 278 managerial workers employed in Gumi industrial complex and the observation period was for 1 month(February to March), 1995. In this study, as a questionnaire for the assessment of work ability, we used the work Ability Index(WAI) which was developed by Institute of Occupational Health in Finland. Major findings obtained from this study were as follows; WAI was poor in lower economic condition, shift work, irregular diet group(p < 0.05). There were no evident trends of WAI in sex, educational level, obesity index, exercise, smoking, and alcohol drinking. In the groups of sensitive to perception of stress, other industrial classification except textile and electronics, the more than 9 hours work, the evident trends of poor WAl were observed(p<0.01). In the groups of 30-39 years old, 40-49 years old, unmarried, high school, shift work, standard body weight, and regular diet, WAl between manufacturing workers and managerial workers was significantly different(p<0.01) and WAI of managerial worker was worse than that of manufacturing worker.

Pilot Study for the Assessment of Physical Fitness among Male Workers in a TV Component Manufacturing Factory / 예방의학회지

In a TV component manufacturing factory, 102 male workers aged 20~39 years old were participated in testing for physical fitness. At the same time, worker's periodic health examination was done. Test battery for physical fitness include grip strength, trunk flexing, standing long jump, side step, single leg balance with eye close, push ups and Harvard step test. As a result of testing for physical fitness, synthetically, there is no difference between manufacturing workers and officers. By bioelectrical impedance test, it means a declining tendency to all 7 factors in the obese workers, and so, it is important for obese workers not only to promote physical fitness but also to promote health. Excluding grip strength and single leg balance with eye close, 5 fitness factors are negatively associated with degree of diastolic Blood pressure, but it is statistically not significant. And levels of SGOT & SGPT have no association with physical fitness factors.

Comparison of Subjective Symptoms of Workers in Rapidly and Weekly Rotating Shift Systems / 예방의학회지

Some circadian rhythms can become disorganized due to rotating shift work. This lack of organization, termed desynchronization, can produce a group of symptoms such as insomnia, GI disturbance and fatigue among many rotating shift workers. The magnitude of these symptoms are influenced by personal and environmental factors and the patterns of shift work. This study was carried out to investigate the subjective symptoms related to rotational schedules of shift work after personal and environmental factors adjusted. 182 male workers in rapidly rotating shift system and 86 male workers in weekly rotating shift system were conducted the questionnaire on personal factors and subjective sleep, GI and fatigue symptoms. Major findings obtained from this study are as follows: 1. The symptoms of 'feeling tired at work' and 'being irritable' were more frequent in weekly rotating shift workers(P<0.05), and the mean of symptom score was significantly higher in weekly rotating shift workers(P<0.01). 2. According to 6 hours of sleeping which is a definite elevation point of fatigue, there was not a significant difference between two groups in sleeping hours. Among workers in rapidly rotating shift system, the mean of symptom score was significantly higher in workers of less than 6 hours of sleeping(P<0.05), but it was not different among weekly rotating shift workers. 3. The symptoms of GI disturbance were more frequent in weekly rotating shift workers but statistically mot significant. 4. The positive rate of mental and physical fatigue symptoms were significantly higher in weekly rotating shift workers(P<0.01) and mental and physical fatigue symptoms were more frequent in them(P<0.01). 5. After the effect of the factors that were significantly different between two groups by X2-test were controlled, the mean score of sleep disturbance was significantly higher in weekly rotating shift workers(P<0.01) and mental physical fatigue symptoms were more frequent in them(P<0.01). Based on these study results, subjective symptoms were more common in the weekly rotating shift workers. In future, medical examination and laboratory test will be also administered to evaluate a more accurate health outcomes and the review of current shift schedules will be required.

The Effect of VDT Work on Vision and Eye Symptoms among Workers in a TV Manufacturing Plant / 예방의학회지

This study was conducted to evaluate the effect of VDT work on eyes and vision among workers in a TV manufacturing plant. The study subjects consisted of 264 screen workers and 74 non-screen workers who were less than 40 years old male and had no history of opthalmic diseases such as corneal opacities, trauma, keratitis, etc and whose visual acuity on pre-employment health examination by Han's test chart was 1.0 or above. The screen workers were divided into two groups by actual time for screen work in a day; Group 1, 60 workers, lesser than 4 hours a day and group 11, 204 workers, more than 4 hours a day. From July to October 1992 a questionnaire was administered to all the study subjects for the general charateristics and subjective eye symptoms after which the opthalmologic tests such as visual acuity, spherical equivalent, lacrimal function, ocular pressure, slit lamp test, fundoscopy were conducted by one opthalmologist. The proportion of workers whose present visual acuity was decreased more than 0. 15 in comparison with that on the pre-employment health examination by Han's test chart was 20.6% in Group Ii, 15.0% in Group I and 14.9% in non-screen workers. However, the differences in proportion were not statistically significant. The proportion of workers with decreased visual acuity was not associated with the age, working duration, use of magnifying glass and type of shift work (independent variables) in all of the three groups. However, screen workers working under poor illumination had a higher proportion of persons with decreased visual acuity than those working under adequate illumination (P<0.05). The proportion of workers whose near vision was decreased was 27.5% in Group II, 18.3% in Group I, and 28.4% in non-screen workers and these differences in proportion were not statistically significant. Changes of near vision were not associated with 4 independent variables in all of the three groups. Six out of sever-subjective eye symptoms except tearing were more common in Group I than in non-screen workers and more common in Group II than in Group I (P<0.01). Mean of the total scores for seven subjective symptoms of each worker (2 points for always, 1 point for sometimes, 0 point for never) was not significantly different between workers with decreased visual acuity and workers with no vision change. However, mean of the total scores for Group II was higher than those for the Group I and non-screen workers (P < 0. 01). Total eye symptom scores were significantly correlated with the grade of screen work, use of magnifying glass, and type of shift work. There was no independent variable which was correlated with the difference in visual acuity between the pre-employment health examination and the present state, the difference between far and near visions, lacrimal function, ocular pressure, and spherical equivalent. Multiple linear regression analysis for the subjective eye symptom scores revealed a positive linear relationship with actual time for screen work and shift work(P<0.01). In this study it was not observed that the VDT work decreased visual acuity but it induces subjective eye symptoms such as eye fatigue, blurred vision, ocular discomfort, etc. Maintenance of adequate illumination in the, work place and control of excessive VDT work are recommended to prevent such eye symptoms.

Cohort Observation of Blood Lead Concentration of Storage Battery Workers / 예방의학회지

To assess the effectiveness of the interventions in working environment and personal hygiene for the occupational exposure to the lead, 156 workers (116 exposed subjects and 40 controls) of a newly established battery factory were examined for their blood lead concentration (Pb-B) in every 3 months up to 18 months. Air lean concentration (Pb-A) of the workplaces was also checked for 3 times in 6 months interval from August 1987. Environmental intervention included the local exhaust ventilation and vacuum cleaning of the floor. Intervention of the personal hygiene included the daily change of clothes, compulsory shower after work and hand washing before meal, prohibition of cigarette smoking and food consumption at the work site and wearing mask. Mean Pb-B of the controls was 21.97 +/- 33.6 microgram/dl at the preemployment examination and slightly increased to 22.75 +/- 3.38 microgram/dl after 6 months. Mean Pb-B of the workers who were employed before the factory was in operation (Group A) was 20.49 +/- 3.84 microgram/dl on employment and it was increased to 23.90 +/- 5.30 microgram/dl after 3 months <(P<0.01). Pb-B was increased to 28.84 +/- 5.76 microgram/dl 6 months after the employment which was 1 month after the initiation of intervention program. It did not increase thereafter and ranged between 26.83 microgram/dl and 28.28 microgram/dl in the subsequent 4 tests. Mean Pb-B of the workers who were employed after the factory had been operation but before the intervention program was initiated (Group B) was 16.58 +/- 4.53 microgram/dl before the exposure and it was increased to 28.82 +/- 5.66 microgram/dl (P<0.01) in 3 months later (1 month after the intervention). The values of subsequent 4 tests remained between 26.46 and 28.54 microgram/dl. Mean Pb-B of the workers who were employed after intervention program had been started (Group C) was 19.45 +/- 3.44 microgram/dl at the preemployment examination and gradually increased to 22.70 +/- 4.55 microgram/dl after 3 months (P<0.01), 23.68 +/- 4.18 microgram/dl after 6 months, and 24.42 +/- 3.60 microgram/dl after 9 months. Work stations were classified into 4 parts according to Pb-A. The Pb-A of part I, the highest areas, were 0.365 mg/m3, and after intervention the levels were decreased to 0.216 mg/m3 and 0.208 mg/m3 in follow-up tests. The Pb-A of part II was decreased from 0.232 mg/m3 to 0.148 mg/m3, and 0.120 mg/m3 after the invention. Pb-A of part III and IV was tested only after intervention and the Pb-A of part III were 0.124 mg/m3 in January 1988 and 0.081 mg/m3 in August 1988. The Pb-A of part IV, not stationed at one place but moving around, was 0.110 mg/m3 in August 1988. There was no consistent relationship between Pb-B and Pb-A. Pb-B of the group A and B workers in the part of the highest Pb-A were lower than those of the workers in the parts of lower Pb-A. Pb-B of the workers in the part of the lowest Pb-A increased more rapidly. Pb-B of group C workers was the highest in part I and the lowest in part IV. These findings suggest that Pb-B is more valid method than Pb-A for monitoring the health of lead workers and intervention in personal hygiene is more effective than environmental intervention.

Standard Body Weight in Korean Industrial Workers / 대한산업의학회지

To contribute to promotion of health and preservation of labor power of Korean laborers, the body height and body weight were measured for 10,407 workers (6,201 male, 4,206 female) in the age group of 20-29, engaged in manufactures in the Gumi industrial complex, Gumi city, Kyungpook province. The above data were extracted from the 1985 periodic examination chart for calculation of the mean body weight, mean body height, correlation coefficient and regression equation between weight and height, standard body weight, body mass index(BMI) and distribution of laborers within Garrow's classification of BMI by age and sex group. Mean body height of 20-29 age group was 168.2+/-5.61 cm for male and 155.9+/-5.26 cm for female. Mean body weight of 20-29 age group was 61.4+/-6.56 kg for male and 52.4+/-6.00 kg for female. Correlation coefficient and regression equation of 20-29 age group were +0.541 and Y(Wt)=0.632X(Ht)-44.975 for male and +0.559 and Y(Wt)=0.637X(Ht)-46.898 for female. Standard body weight of 20-29 age group was 53.0kg at 155cm, 59.3kg at 165cm, 65.6kg at 175cm for male and 51.8kg at 155cm, 58.2kg at 165cm, 64.6kg at 175 cm for female. Range of normal body weight of 20-29 age group was 47.5+/-58.5kg at 155cm, 53.8+/-64.8kg at 165cm, 60.1+/-72.1kg at 175cm for male and 46.9+/-56.8kg at 155cm, 53.2+/-63.2kg at 165cm, 59.6+/-69.6 kg at 175 cm for female. Range of obesity of 20-29 age group was 64.1kg and over at 155cm, 70.3kg and over at 165cm, 76.7kg and over at 175cm for male and 61.8kg and over at 155cm, 68.2kg and over at 165cm, 74.5kg and over at 175 cm for female. Body mass index (kg/m2) of 20-29 age group was 21.7+/-1.95 for male and 21.6+/-2.05 for female, 75.9% of male laborers and 71.3% of famale counterparts fall in the desirable range of BMI by Garrow's classification.