The present study was carried out to: 1) assess cadmium content in both rice and soil of China, Indonesia and Japan, 2) determine the relation of cadmium content in rice and soil to soil type and country, and 3) estimate the average daily cadmium intake from rice from the results of cadmium analysis and rice consumption data of FAO. Much data on cadmium content in rice and soil of Japan have been reported (Iimura 1981; Masironi et al., 1977; Morishita 1981; Moritsugu et al., 1964; Nakatsuka et al., 1988; Yanagisawa 1984), but those for Indonesia are limited (Suzuki et al., 1988; Rivai et al., 1990). Moreover, the only data on cadmium content in rice of China have been reported by Rivai et al.(1990), none are available on the cadmium content in soil of China. Rice is a major source of cadmium intake for man in rice eating countries such as China, Indonesia and Japan. Thus, rice may be the best indicator to monitor cadmium exposure. Iimura (1981) reported the mean cadmium content in brown rice and paddy soil of Japan to be 90 and 450 ppb, respectively. Yanagisawa et al. (1984) found this parameter in brown rice and paddy soil from polluted area of Japan to be 0.37 and 1.35 ppm, respectively. Hutton et al. (1987) found the major sources of cadmium pollution to the agriculture land in England to be sewage disposal, manufacture manufacture and phosphate fertilizer. Morishita (1981) and Asami (1981) reported that rice grown in polluted soil contains more cadmium than that of non polluted soil. However, there are no data on relationship between cadmium content in rice and soil to the soil type. Assessment of the accumulation of cadmium content in rice and soil by soil type may also facilitate environmental monitoring. Daily cadmium intake from rice may be estimated from cadmium content in rice multiplied by daily rice consumption. Ohmomo (1981) reported the daily cadmium intake from rice of Japan to be 26 μg/person. Though the biological role of cadmium is not known for plants, under certain conditions it may accumulate in some plants to levels hazardous for animals and finally for man at the end of the food chain. This element, after entering into the soil would not be leached out and thus accumulate. Some of it is absorbed by plants that are a part of the ecological cycle. The hydrochloric acid extraction method can be used to detect the soluble fraction of the element absorbable from the roots of rice plants (Nihon Dojo Hiryo Gakkai 1986).
This study explores health-related behavior and its sochial-psychological background of the inhabitants in Oshima-mura, a typical sparsely depopulated area, Higashi-kubiki County, Niigata Prefecture. After having interviewed several households about healthrelated behavior in general, we conducted a questionnaire survey of the heads of 140 households examining statistically the relationship between health-related behavior and its social-psychological background. The results are summarized as follows: 1) Users of unorthodox medicine are not limited to elderly people. A significant difference in the rate of utilizing unorthodox medicine is not found between people of 65 years or more and the others. And the older people are, the more they use preventive measures to maintain health. 2) Anxiety about the insufficiency of the medical care concerned is independent of that about their own health. Preventive health behavior is associated with the former, but not with the latter. And the more they are anxious about their own health, the more they tend to use unorthodox medicine. 3) Age is associated strongly with some of social-psychological variables and healthrelated behavior. Though it is not associated with anxiety about their own health, the older people are, the less anxious about the medical care concerned they are. 4) From the findings above, unorthodox medicine in the area concerned functions complementarily rather than opposedly to orthodox medicine. 5) We think that an interview and a questionnaire survey in two steps is an effective method studying health and medical care in a local area.
The purpose of this study was to ascertain whether there are any socioeconomic or environmental factors possibly contributing to childbirths related to sex. Using the vital statistics issued by the Kagoshima prefectural government, secular changes in sex ratio at births were studied over a 20-year period 1968 to 1987. The relationships between sex ratio at births and the indicators of selected socioeconomic conditions or the measures of some ionic concentrations in drinking water were also examined among 96 local community units (city, town and village) in Kagoshima prefecture . The following results were obtained: 1) The sex ratio at births has slowly and progressively declined in Japan as a whole in the course of a 20-year period 1968 through 1987, the decrease being from 1.071 in 1968 to 1.058 in 1987. The sex ratio at births in Kagoshima prefecture, however, has shown a slightly increasing tendency rather than a decreasing tendency over the same study period, although it was generally below the levels in Japan as a whole. 2) A progressive decline in gross fertility rate by the passage of the year was observed in Japan as a whole during the period 1968 through 1987. Similar trend has occurred in Kagoshima prefecture, although the rate was always above the levels in Japan as a whole. The declining fertility appears to have played a role in the decline in sex ratio at births. 3) The values of sex ratio at births differed considerably among the 96 local community-based aras (city, twon and village), the highest, 1.457 was for Mishima village and the lowest, 0.819 was for Toshima village. Both of these two villarges were on the solitary islands and sparsely populated. 4) Of seven indicators of socioeconomic condition (percentage of junior childbearings, percentage of senior childbearings, percentageof girls who enter senior high schools, gross fertility rate, crude birth rate, percentage of primary industries and gross income) studied, only the percentage of senior childbearings was inversely correlated with sex ratio at births. Also, of seven ionic concentrations in drinking water (Na, K, Mg, Ca, Cl, SO4 and CO3), Na, Cl and SO4 were positively correlated with sex ratio at births.
To study seasonal variations in blood pressure in Okinawa, a Japanese subtropical island, we examined 100 hypertensive and another 100 normotensive subjects for one year and obtained the mean blood pressure for each month. Major findings were as follows: 1) Blood pressure was lower in summer than in winter for each group of hypertensive, diabetic, normotensive, older and younger subjects. 2) Blood pressure in hypertensive diabetic subjects and hypertensive older subjects rapidly rose in autumn. 3) Blood pressure in normotensive younger subjects declined mostly in summer. 4) Although seasonal variations and trends in the blood pressure of Okinawan subjects were similar to those of Japanese mainland subjects, the Okinawans showed a consistently lower blood pressure than that of the mainlanders by about 10 mmHg for both systolic and diastolic values.
In order to investigate the relationship between the indexes especially concerning cerebro-cardiovascular diseases and the health practice and social network as life style, we analyzed the data of 493 adult males and females in community. In this study, we used multivariate analysis and tried to visualize the results in a three-dimensional space. The results are as follows. 1) In the factor analysis of the objective health indexes, we could realize the 1st factor of female was "the factor of adult diseases", while in contrast that of male was "the factor of hypertension". 2) There was a significant negative correlation in male between the factor score of "the factor of hypertension" and each item which expressed social networks especially outside the home. In female, the total score of health practices was significantly correlated to each factor of objective health indexes. 3) We also made the correlation analysis between the scores of each principal component of 13 items of health practice and social network and these of each factor of objective health indexes. In male, "the factor of hypertension" showed a significant negative partial correlation to the 1st component, which we called "the index of activity", unrelated to the factor of age. 4) The difference between male and female could be recognized visually in a threedimensional space in which we expressed the above results. As mentioned above, the structure of life style and health status showed a significant difference between males and females. The results suggested that objective health indexes correlated to social network outside the home in male and to health practices in female.