[Studies on health hazards among cooks providing school lunch service. Report 1. The influence of working conditions in central and school kitchens prevalence of health hazards].

Since the School Lunch Law was enacted in 1954, the school lunch program in Japan has seen rapid development, mainly in compulsory schools. Eighty-four percent of all pupils in compulsory schools are fed lunch, and nearly half of the meals are provided by the central kitchen system. There has been much criticism of the central kitchen system concerning the quality of the meals. Recently, it has been demonstrated that many cooks suffer from musculo-skeletal symptoms in their necks, shoulders, arms and lower backs. This paper discusses the relationship between the cooking work load and health hazards by comparing the tasks of cooks in the central kitchen system with those of cooks in individual school kitchens. All the female cooks in one prefecture were queried by a mail survey method. The respondents totalled 1,428 (response rate 68%). Of this number, 186 work in 15 central kitchens (group C) and the other 1,242 work in 401 school kitchens (group S). In addition physical examinations were carried out on cooks who registered serious complaints in the questionnaires and on those who wanted to undergo the examination. The results are as follows: The work load in the central kitchens is greater than that in the school kitchens. Both groups C and S complained of cervicobrachial symptoms and low-back pain as frequently as other workers already reported to be in a high risk of these hazards. Group C suffer from these hazards more frequently and seriously than group S. Group C assigned "carrying heavy objects" as a cause of low-back pain and cervicobrachial symptoms more frequently than group S. This was related to the difference in numbers of meals served by groups C and S. As a result of the physical examination, serious cases of cervicobrachial disorders and/or low-back pain were found more frequently among cooks who had serious complaints than among other examinees. It was concluded that these results demonstrated a positive relationship between the cooking work load and the development of health hazards. Therefore, if we wish to protect cooks from these hazards, it is not advisable to maintain the current central kitchen system.

[Studies on health hazards among cooks providing school lunch service. Report 2. An analysis of factors associated with the development of health hazards].

The previous report revealed that the musculoskeletal symptoms of cooks are related to their working conditions, but the cause and effect relationship was not clarified. In the present report, the relationship between some causative factors and the health hazards is analyzed epidemiologically. The subjects were chosen from the cooks mentioned in the previous report. The results are as follows: A clear relationship was not observed between age and health hazards. A dose-response relationship was observed between the cumulative duration of cooking work and the subjective symptoms. An antecedent-consequent relationship was also shown between the cooking work and the health hazards. Another dose-response relationship was observed between the amount of cooking work and the subjective symptoms. The frequency of "carrying heavy objects" assigned as a cause of development of the hazards, especially of low-back pain, increased in accordance with the number of meals served in each kitchen. It was observed that the improvement of cooking equipment enabled the incidence of symptoms to decline, but the elevation of working speed due to mechanization could still be hazardous. As a result of the physical examination, a similarity was observed between the cooking work and the clinical findings in comparison with ticket-vending machine operators. It is concluded that these results demonstrate a cause and effect relationship between cooking work and the development of health hazards.

[Studies on the cervicobrachial disorder among cash register operators. Part 1. Changes of characteristics of patients after improvement of working conditions].

Occupational cervicobrachial disorders (OCD) among cash register operators have become an important problem since 1969. Some improvements of working conditions, such as, shortened operating time, adoption of worker rotation system and change of mechanical registers with heavy keytouches to electronic ones with light keytouches, were introduced in 1973-1974 at supermarkets at which the authors engaged in health care activities for the prevention of the disorder. Analysis was made for characteristics of 120 cash register operators of these supermarkets suffering from OCD during the period from 1972 to 1978, with special concern for differences before and after the improvement of working conditions. The subjects were divided into three groups by the year of their first consultation, A: 1972-1973, B: 1974 and C: 1975-1976. Patients of group A had engaged in cash register operation under the working conditions before improvements, and those of group C had engaged after improvements of working conditions. The authors observed that the incidence of the disorder among group C were less than that of group A, but the proportion of severe cases to all the patients were not changed. In group C more cases with chronic onset were observed than among the other two groups, and those patients with chronic onset took longer period for recovery compared with the other patients. In patients of group C compared with those of group A fewer complaints and muscle tenderness in the hands and fingers were noticed, and more cases with lowered back strength and cinesalgia of the neck were observed. The reasons for this were considered to be that the improvement of working conditions reduced the loads to the hands, but not much reduced the loads to the neck and the back.

[Studies on the cervicobrachial disorder among cash register operators. Part 2. A review on clinical findings and working conditions of patients].

Complaints, clinical findings and working conditions of the patients suffering from occupational cervicobrachial disorders (OCD) were discussed, with special reference to the prognosis of the patients. Subjects were 120 cash register operators with OCD engaged in supermarkets at which the authors participated in the health care activities for the prevention of the disorder. Thirty-three of them suffered from the disorder after getting well from the first onset. The authors discussed on the relationship between complaints and clinical findings of the patients and duration needed for recovery, the relationship between clinical finding and complaints of "the upper extremities" by the questionnaire of "complaints in daily life" and the relations of appearance of lowered grip strength to complaints and clinical findings. Case studies were also examined as to the influence of working conditions on the prognosis of the patients. Results were summerized as follows. 1. The severer the grade of OCD, the longer the duration needed to recover. 2. There were more complaints of arms, "the upper extremities" and "the legs", increased appearance of lowered back strength, cinesalgia of the shoulder, neck, and wrist joints, paresthesia, positiveness of Morley's test and muscle tenderness in the extensor muscles in the fingers, neck, back and so on among the patients with delayed recovery than among those recovered within 3 months. 3. Lowered back strength, muscle tenderness in the neck and in various sites of the body were observed more among the patients with many complaints of "the upper extremities" than among those without. 4. Lowered grip strength was not considered to be useful for early diagnosis of the patients. 5. Such working conditions, as carrying heavy goods and keeping upper extremities raised for a long time were considered to hamper the recovery of the disorder.

Recent trends in research on occupational cervicobrachial disorder.

Recent rapid development of mechanization and automatization in many industries in Japan have increased simple and repetitive tasks that have resulted in some new types of occupational health hazards, in particular among young female workers. One of them is occupational cervicobrachial disorder, the concept of which was established by the committee organized by the Japan Association of Industrial Health in 1972. The committee demonstrated that the disorder resulted from repetitive upper limb manipulation in punching and operating various kinds of business machines, and concluded that the disorder was closely related to chronic fatigue in the shoulders, neck, lower back and other parts of the body. In 1975 a study team was organized with a grant from the Ministry of Education. The team was divided into four working groups. Topics of these groups were 1) etiology of the disorder, 2) natural history of the disorder in various kinds of jobs, 3) mass examination techniques for the disorder, and 4) a health care system to be provided for the workers. The persent report summarizes the results of group discussions with a view to indicating the current problems of occupational cervicobrachial disorder and the necessary future steps for its care treatment and prevention.