Finger dermatitis among perilla workers have been reported since 1970 in Japan. The agricultural chemicals used for perilla culture and the allergic effects of the perilla itself are discussed as for the causative factors of the dermatitis. In this report, epidemiological survey and dermatological examination were carried out, with special concern for the prevalence of hazards of each fingers of the workers in relation to their work process, especially picking perilla leaves. Subjects were all of 152 workers who engaged in perilla culture in 2 area in Nankoku, Kochi Prefecture. And the skin patch testing for 32 workers (17 ones with dermatitis and 15 ones without dermatitis) and 20 controls was done using samples of the leaves cultivated without agricultural chemicals for more than 3 weeks and perilla oil extracted from them. Results were as follows. 1. Skin hazards of the fingers, such as erosion, fissure, desquamation, thickening or bleeding were observed among about half of the workers. 2. The hazards were more frequently observed among the workers whose working hours for perilla culture and picking perilla leaves were longer. 3. The hazards were more frequently observed in the fingers touching the reverse sides of the leaves which had the secreting glands than in those touching the surface sides, on which might be contaminated by agricultural chemicals. 4. The perilla oil acted as the irritating substance for almost all of the examinee, and the skin patch testing demonstrated that both the perilla leaves and their oil caused allergic reactions to the workers with dermatitis. 5. It was considered that the perilla leaves and their oil had played an important role of a cause of the dermatitis among the perilla workers.
To estimate the amount of particles which enter into the body by inhalation and rest on the wall of the respiratory tract when farmers are dusting crops with pesticides, I took the size of dust particles and plotted the measurements on distribution charts. Results are as follows: 1. The particle distribution of dust type pesticides (original) showed that particles of 2 μ or smaller top all the rest. A steady downward curve was observed from 2 μ to 10 μ, but from 10 μ on, slight increases were noted. As a whole, particles of less than 10 μ accounted for 87%. 2. The particle distribution of pesticides inhaled by farmers during spraying work showed a significantly high ratio of particles of 2 μ or smaller when compared with that of the original. As for particles of 2 μ or larger, the distribution tendency was similar to that of the original. 3. In view of the fact that a relatively large quantity of particles of less than 2 μ was inhaled and that labor intensity of farmers dusting over paddy rice fields by use of powered sprayers is high, it is presumed that the amount of pesticide dusts entering deep into the respiratory tract and alveoli of the lung is large. Hence, it would be necessary to provide proper guidance to farmers for the prevention of pesticide-induced maladies.
In the present study, we undertook the investigation into health conditions and subjective symptomes by spraying pesticides on farmers in citrus fruit area in Ehime Prefecture. 65 males and 138 females were examined for their health conditions in August, 1981 and the prevalence rate of anemia was 6.2% in males and 37.0% in females, that of hypertension was 20.0% in males and 20.3% in females, and that of the disturbance of liver function was 17.0% in males and 2.8% in females. There was a serious problem in farmers that the subjects taken these diseases usually sprayed pesticides. The investigation into subjective symptomes by spraying pesticides was performed for 50 males and 54 females from May to July, 1981. The frequency of spraying pesticides was about 2.5 times per sprayer in May and June, but about 5 times in July. Time of spraying was about 5 hours and dithiocarbamates was most frequently used. The tendency of combinational use with several pesticides was recognized in July than in May and June. The wearing rates of waterproof coat and trausers were high but those of dustproof mask and rubber gloves were low. The incidence rate of subjective symptomes by spraying pesticides was 10.4% in males and 17.0% in females in May, 14.3% in males and 27.8% in females in June, and increased to 42.0% in males and 63.0% in females in July. Skin lesion was the most frequent symptome, excessive sweating and general fatigue followed this. Further studies on skin hazards due to pesticides are necessary.
The examination of the optic fundus constitutes an essential part of the mass health screening course. However, the significance and the use of its findings are yet to be clarified fully. So, we have recently conducted two research studies. One is concerned with quantitation of information made available about the changes in the blood vessels in the retina of the eye. Following a basic investigation in which the diameter of retinal vessles was measured, we examined changes in the diameter of retinal arteries after administration of vasodilators in search of the relationship between vasodilation and arteriosclerosis. The other is concerned with a comparative study of abnormal retinal findings and the occurrence of cerebral apoplexy. We closely examined the appearance ratios of retinal abnormalities and compared them with the data obtained in our previous study of the incidence of cerebral apoplexy over the period of five years. The subjects are rural inhabitants of the Yuri district, Akita Prefecture, which is noted for its high incidence of cerebral apoplexy in this country. Particularly in the Yuri district, not only the aged but people under 60 years of age are frequently attacked with cerebral apoplexy. Our current survey findings showed that the average diameter of retinal vessels-both arterial and venous-was slightly small compared with those reported by other researchers. The dilation of retinal arteries after intravenous injection of 20mg of nicotinic acid was large in the moderate arteriosclerosis group and small in the advanced arteriosclerosis group. The appearance of retinal abnormalities increased as the age of the subjects advanced. Hypertensive retinopathy was predominant among those aged between 30 and 49, while among those aged 50 or above arteriosclerotic changes were observed as frequently as any abnormality. Irrespective of age, the subjects who showed retinal abnormalities developed symptoms of cerebral apoplexy at a significantly higher rate than those who did not show any abnormality in the eyeground. Particularly, the narrowing of the retinal arterioles was observed at a notably high rate. Thus, it has been proved that the eyeground examination is effective in predicting cerebral apoplexy and useful in mass health screening.