I would like to report on the statistical observation of major zoonoses in the rural districts of our country.
The agricultural management of Japan is on a small scale, especially that of livestock.Recently domestic animals have been slightly on the increase (see Table 7). Of late, livestock hygiene centres have increased (from 107 in 1948 to 532 in 1965), which are equipped with modern facilities.The number of investigations have also increased.For these reasons, our investigation of zoonoses will become more modernized hereafter.
Salmonellosis and Encephalitis are not so closely linked with agriculture, but it is true that these diseases mainly break out in rural districts. Preventive measures must be taken from the point of view of rural medicine.

The pollution of our environment by a variety of mutagenic agents has been at issue in the last few years. The herbicide 2, 4, 5-trichlorophenoxyacetic acid (2, 4, 5-T) has turned out to be a potent mutagenic agent. Therefore, we evaluated the cytogenetic effect of this compound on the human leukocyte in vitro. Chromatid aberrations were observed and it was found that their incidence increases in proportion to a rise in dose.
It has been claimed that the teratogenic effects of 2, 4, 5-T may be attributed to the presence of 2, 3, 7, 8-tetrachlorobenzo-p-dioxin (dioxin) as an impurity. The compound used in our study contained 0.09μg/g of dioxin. Although the level of contamination is low, the possible roleof dioxin cannot be ruled out. Nevertheless, the fact remains that the mutagenic effects of the compound now available are undeniable.

Recently, there have been signs of a rise in the number of farm workers with lumbago. The authors have surveyed and researched farm workers' complaints about lumbago and the relations among lumbago, farm work and daily life. The findings revealed that:
1) Complaints about lumbago are evidenthly greater among farm workers than other people.
2) People with complaints about lumbago increase with age. Men and women in their 40s reach a peak.
3) In terms of farm work, the rate of complaints about lumbago is great for forward-bending and half-sitting postures and for the carrying of heavy objects and the bending and stretching of the waist. In terms of the work environment, cold weather produces a great impact on the incidence and degeneration of lumbago.
4) In checkups of people with lumbago, there are many cases with muscular and myofasiogenic lumbago.
5) Complaints have something to do with an elapse of time. Daily calithenics is believed to the alleviation of complaints about lumbago.