福島県下林業民間労働者の振動障害

抄録

A field study of vibration syndrome has been made on 404 forestry workers (among whom 2 women were included) employed in 95 private enterprises in Fukushima Prefecture. The investigation was carried out from January to March of 1976 and from December of 1976 to February of 1977. Questionnaires and interviews concerning the history of vibration exposure and the occurrence of vibration syndrome were used, and standard medical examinations for the vibration syndrome, i.e. examinations of cutaneous senses and peripheral vascular functions of the hands, were carried out in every subject. Data of work conditions, subjective symptoms, sensory thresholds and peripheral vascular functions among workers were analysed and summarized as follows: 1. Ninety-seven percent of the subjects had been engaged exclusively or mainly in the chain saw work, while 3% of them exclusively or mainly in bush cleaner work. 2. Prevalence of Raynaud's phenomenon was found in 30.9% of all the subjects, and attack rate of the phenomenon exceeded 50% of the workers after 11 years of work with vibrating tools. Of all 404 workers 5.7% had suffered from the phenomenon only a year or more before the time of the investigation. 3. Average working hours per day with vibrating tools of the sufferers from the phenomenon was longer than those of non-sufferers. 4. Seventy percent of them were pieceworkers. It was supposed that they could not shorten the time of work with vibrating tools under the system of piecework payment. 5. Symptoms of which twenty-five percent or over of all the workers complained were numbness or paresthesia, chilling, shoulder stiffness, transient lumbago, increasing fatigability, heavy feeling in the arms, high sensitiveness to cold, inclination to wear heavy clothes and pains in the hands or the arms. 6. Cardinal symptoms of which sufferers from the phenomenon complained more than non-sufferers were chilling, numbness or paresthesia, high sensitiveness to cold, heavy feeling in the arms and pains in the hands or the arms. 7. Sufferers from the phenomenon had higher prevalence of disturbances than non-sufferers in the pain sense and the vibratory sense of the hands, and they also showed slightly higher prevalence of low skin temperature and of prolonged recovery time of the blood flow in the hail-bed. 8. It was considered that the higher prevalence of sensory disturbances and peripheral vascular dysfunctions among the sufferers might be attributed to their longer working hours in a day with vibrating tools. 9. It was noteworthy that there were not a few workers among the non-sufferers who showed a high degree of sensory disturbances. 10. There was a correlation of thresholds between pain sense and vivratory sense among the non-sufferers but not among the sufferers. 11. Correlations between skin temperature and recovery time of the blood flow in the nail-bed were observed both among the sufferers and among the non-sufferers.