In order to evaluate the functions of the peripheral somatic nerve and autonomic nerve in patients with occupational vibration disease objectively and quantitatively, four examinations were performed on twenty 44-63 yr old patients with occupational vibration disease and their total operating time ranged from 5, 000 to 43, 750 h.
1) Motor nerve conduction velocities (MCV) and sensory nerve conduction velocities (SCV) of the ulnar and median nerves were measured using conventional methods.
2) Electrogustatory thresholds under the controlled area of the chorda tympani nerve were measured by Tomita's method using an electrogustometer (610-M, M. E. C.).
3) Dopamine-β-hydroxylase (DBH) activity in blood was assayed by the photometric assay of Nagatsu and Udenfriend.
4) Coefficient of variation of R-R interval in ECG (CV^R-R) was measured after 15-min-resting in supine position by using a R-R interval analyzer (Autonomic R 100, M. E. C.).
The results of these examinations were compared with those of special examinations for the diagnosis of vibration disease.
In patients with occupational vibration disease, MCV and SCV of the ulnar and median nerve were lower in value than those in age-matched healthy controls. In particular, MCV of the ulnar nerve, MCV and SCV of the median nerve were significantly lower in the patients than in the controls. Nerve conduction velocities were significantly correlated with skin temperature and nail-press test, though diminished nerve conduction velocities observed in vibration disease patients were considered to be attributable to peripheral circulatory disturbance.
Electrogustatory thresholds under the controlled area of the chorda tympani nerve in the patients were significantly higher than those in age-matched healthy controls, suggesting that the gustatory function was disturbed in patients with vibration disease.
DBH activities in patients with vibration disease were significantly higher than those in healthy controls, suggesting that the sympathetic nerve function was accelerated in the patients.
CV R-R in the patients was significantly lower than in age-matched healthy controls. It was suggested that the function of the parasympathetic nerve (especially the cardiac branch of vagus) was decreased in patients with vibration disease.
These findings suggest that these examinations are useful in elucidating the pathogenesis of vibration disease.

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Hardly any practical approaches have been made on prediction of appearance of heat-stress hazard, although basic studies have extensively been made, including various heat-stress indices. Hence, in the present paper, an applicational prediction equation is presented with regard to the permissible working time without heat-stress hazard on the basis of experimental results.
The purpose of this experiment was to examine the significant correlations between elevated rectal temperature, working conditions such as wearing suits, work load, and environmental temperature. The results obtained can be summarized as follows.
(1) A critical level of environmental temperature exists. When this level is exceeded, physiological indices such as rectal temperature rapidly increased. According to experimental results, the critical level was about 30°C and the heavier the work load, the lower was the critical level.
(2) Moreover, the heavier the wearing suit, the lower became the temperature level. This finding indicated that it was important to choose a suitable apparel under a hot environment in order to keep the workers safe from heat-stress hazard.
(3) A general prediction equation of raising the level of rectal temperature compared with that of initial condition was proposed by analysing each experimental condition (suit, work load, and environmental temperature) by use of second order multiple regression method. This equation showed that elevation of rectal temperature was assumed to be proportional to the logarithm of the working periods.
(4) The predicted values by this equation corresponded with the experimental values within ±0.2-0.3°C, and the correlation coefficient was 0.96. This equation suggests that heavier suits elevated the rectal temperature about 2-3°C when the work load and environmental temperature were moderate.
(5) It is possible to predict the permissible working period by this equation. This may be applied to the working plan effectively. Appropriate working conditions can be chosen with regard to apparel, environmental temperature, and work load.

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Mutagenicity of nine epoxy resin hardeners was examined by a fluctuation test modified by Gatehouse. The test was performed by using Salmonella typhimurium TA98 with a metabolic activation system. In our laboratory, the results of the fluctuation test were compared with the results obtained by the previously mentioned Ames preincubation method.
Six out of nine epoxy resin hardeners showed mutagenic activity in both the fluctuation test and Ames preincubation method, but one out of the nine was negative in both test systems. Two out of the nine were positive by either of the two testing systems. The fluctuation test is disadvantageous in that it is marginally slower and requires slightly more labor than the Ames test and furthermore it is difficult to increase the amount of microsome because of background interference. These disadvantages, however, are somewhat offset by the advantages that small organs such as urinary bladder can be used instead of liver cells and that a small amount of microsome can be employed for metabolic activation. This test is also suitable for testing aqueous samples containing low levels of mutagen.

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The number of gainfully occupied couples has been increasing. A survey on the subjective symptoms of fatigue and on life and work was carried out on 996 personnel belonging to a university hospital in order to ascertain their fatigue pattern and the following results were obtained.
1. Both the husbands and wives showed II-dominant type (mental-work type, night-work type) among the three types classified by subjective symptoms.
2. When compared with the results of our previous survey, though T value was not so high, II/T value was high and III/T value was low in both groups of husbands and wives, suggesting a marked tendency of mental fatigue.
3. Difference in complaint rate of fatigue between pre- and post-work in the group of husbands was smaller than that in the group of wives, suggesting that the group of husbands is slower in recovery from fatigue after work.
4. The level of physical activity at work and the amount of physical work such as caring of children and housekeeping was higher in wives, while the husband's work is mental and the amount of physical work is relatively small. Thus, wives appear to recover faster from mental fatigue. It is considered that husbands need to improve their manner of spending their free time.
5. The results of regression analysis on the complaint rate in wives and husbands showed that there is a correlation between the complaint rate of wives and that of their husbands. Therefore, as a counter-measure to fatigue, improvement of life pattern outside of working time is important as well as that of work.

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Vibration syndrome, especially Raynaud's phenomenon, has generally been observed in vibrating tool operators, but the frequency of Raynaud's phenomenon in individuals not using vibrating tools is unknown.
The authors therefore conducted a survey on the prevalence of stiffness of hands, numbness of fingers, and Raynaud's phenomenon among the examinees of Gifu Prefectural Health Care Center and among the female students of Gifu Prefectural Nursing and Paradental School. The following results were obtained by this survey.
1. Prevalences of stiffness of hands, numbness of fingers and Raynaud's phenomenon in female students were 20.9%, 29.5% and 4.6%, respectively, which are 2-3 times higher than those in male adults.
2. The prevalence of Raynaud's phenomenon in female students aged 20-24 yr was equal to that of female adults aged 30-39. It was higher than that of those aged 18-19, 40-49 and 50-59. The prevalence of Raynaud's phenomenon in males did not show any difference by age group.
3. There was no occupational specificity in the prevalence of Raynaud's phenomenon, but the prevalences in male sales workers and in female professional and technical workers were higher than in other groups.

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Occupational exposures at nuclear power plants occur mostly during maintenance activities rather than during routine reactor operation. In this paper, statistical summaries of occupational exposures during routine maintenance activities for the years 1982-84 at nuclear power plants in Japan are presented, including comparison of the exposure levels by reactor type and by plant age.
Average annual collective doses per reactor for BWRs and PWRs are 7.30 man-Sv and 2.84 man-Sv, respectively, and 78% and 89% of annual doses are incurred during maintenance activities. Average annual outage days of BWRs and PWRs for routine maintenance are 102 d and 97 d.
Annual collective doses per reactor, most of which occur during maintenance activities, usually increase with plant age. Higher collective doses are observed for routine maintenance performed on older reactors as compared to newer reactors, especially in BWRs.
Collective doses accrued during respective routine maintenance activities have a significant correlation with duration of maintenance and number of workers involved in maintenance.

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An interview survey on the health care service for workers employed in small-sized enterprises was conducted in a city of Osaka Prefecture. Items surveyed were: 1) number of full-time and part-time employees by age (less than 39, 40-60, and more than 60 yr) and sex, 2) materials and production process, 3) periodic examinations for general health status and occupational diseases, and others. Of the 526 enterprises interviewed, 459 manufacturers with less than 50 employees were analyzed. The results can be summarized as follows:
1. Of the 459 manufacturers, 72.4% were those with less than 10 workers (the mean number of employees: 8.4). The major type of manufacture was electric parts processing industry.
2. The period health examination has been carried out in 372 enterprises (81.0%). The smaller the size of the company, the lower was the rate of the periodic health examination.
3. In 77.4% of the 372 enterprises, only chest X-ray was an item for the periodic health examination, which was usually carried out at the public health center of the community.
4. The number of enterprises conducting the periodic health examination designated by the Industrial Safety and Health Law (1972) was only 49 (10.7%).
5. Fourteen enterprises (3.1%) have carried out periodic examination for occupational diseases.
6. The periodic examination for degenerative diseases such as hypertension, diabetes mellitus, and other cardiovascular diseases was carried out in 57 enterprises (12.4%). The larger the size of the company, the higher was the rate in which such examination was conducted.
These results show that a health care service system in small-sized manufacturers should be urgently established in close cooperation with a community health service system for promoting the general health status of the workers.

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