Exposure to ultraviolet radiation (UVR) occurs from both natural and artificial sources. The main natural source is the sun. On the other hand, artificial UVR sources are widely used in industry and also used in hospitals, Iaboratories, etc. because of their germicidal properties. They are even used for cosmetic purposes. UVR can be classified into three regions according to its wavelength : as UVA (320-400nm), UVB (320-280nm) and UVC (280-200nm). The UVC has the greatest health effect on humans among the three. The sun radiates a wide range of spectrum of electromagnetic radiation including the UVR, however the radiation below 290 nm in wavelength does hot reach the surface of the earth for effective absorption by the strato-spheric ozone layer. As a result, UVR from a natural source consists of only UVA and a part of UVB. On the other hand, artificial UVR sources include UVC region and have serious effects on the human body, especially on the skin and eyes.

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Experiments were conducted to compare the impact on several parts of the body caused by the striking of the heel during human gait. In these experiments, five kinds of wood flooring that have differing levels of light weight-impact sound insulating efficiency were used. The obtained results were as follows : 1) The generated acceleration at calcaneus varied with the difference of flooring. Accord-ing to the regression analysis, the open polygonal relationship between bound back coeffi-cient of floor and acceleration of calcaeus was determined. 2) The impact force given to the calcaneus propagated from the heel to the forehead after most of the force being absorbed at the ankle and the knee. We found direct correlation between the subjective feeling of floor pliabilty and the force to the leg. Therefore, it was suggested that the measurement of the force to the ankle and the knee was important in evaluating the efficiency of floors.

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Excess body fat has generally been considered to be an influential factor to physical fitness and motor ability in obese boys. However, Iittle information is available on the physical fitness and motor ability in obese boys. The purpose of this study was to clarify characteristics of physical fitness and motor ability in obese boys. The subjects were three hundreds and five boys aged 12-14 years. Nineteen physical fitness and motor ability items were tested and skinfold thickness was measured at six sites. Bioelectrical impedance was measured using a tetrapolar impedance plethysmograph (Selco SIF-891). Body density was calculated from the formula of Kim et al. The results of comparison clearly indicated that the obese group was significantly poorer in 1, 500-m run, 5-min run, 50-m run, running long jump and many other variables, but was superior only in back strength. To analyze the factorial structure in boys, principal factor analysis was applied to the correlation matrix which was calculated with 19 variables, and then five factors were extracted. The obese group was significantly poorer in total body endurance and muscular endurance than the non-obese group. From these results, it was confirmed that the excess body fat could be one of the most important factors that affects the state of many physical fitness and motor ability elements in obese boys. However, the relationships between physical fitness, motor ability and the degree of fatness seem to be rather complicated. A great deal of data should be accumulated for more detailed analysis on the influence of the excess body fat in obese boys.

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A group of 11 obese women (from 130 % of ideal weight and higher)volunteered to partici-pate in a study designed to reduce weight in a 92-day program of aerobic exercise. Before and after the weight reduction period, body fat indlces were measured by deuterium oxide (D₂O) dilution and by skinfold anthoropometry. Changes in internal body fat and subcutaneous fat were calculated. Mean weight loss was 3.6±1.2 kg, and internal body fat and subcutaneous fat were 1.8±1.3 kg (21.2 %) and 3.0±0.9 kg (16.0 %), respectively. Highly significant correlation were obtained between changes in internal body fat and total body fat (r = 0.856, p<0.001). However, changes in internal body fat were not significantly associated with changes in waist to hip ratio (WHR). In the present study, we found that changes in total body fat were significantly related to changes in internal body fat during treatment of obesity with aerobic exercise. However, changes in internal body fat were not valid estimates of changes in body fat distribution in relation to changes in WHR.

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Since the health hazard of asbestos fibers has been widely recognized, the number of asbestos abatement projects in schools has increased rapidly. Most of these projects were planned during summer vacation from school. However, in Japan, it is hot and humid in summer. Moreover, the workers have to wear impermeable protective clothing because of the asbestos exposure risk. The purpose of this survey is to study the workload of asbestos abatement work by measuring physiological reactions. Physiological strains of 12 male workers and working conditions during asbestos abatements work in two schools were measured in August in 1988 and in 1989. Body weight loss by the work of all workers was measured, and heart rate, rectal temperature and skin temperatures at five sites of some of them were measured every minute.

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