Based on the Rogers' model the multiregional population analysis focused on Fukuoka prefecture was done by using the 1980 population census and vital statistics data. Whole Japan, excepting Fukuoka, was deviled into 7 regions with consideration to their relationships with Fukuoka prefecture. The results of multiregional life table, expectation of life by regions of birth and residence, number and probability surviving to a specific age in each region, and number of years expected to be lived in various regions, were reported. Studies on fertility and level of migration and the results of multiregional population projection were also given. Multiregional life table study showed a little different results from single region life table reflecting a levelling effect of migration, e.g. considerable reductions of differences in life expectancy among various regions. Of survivors of cohort born in Fukuoka prefecture to the age of 20, 59% and 65% were expected to stay in Fukuoka and 41% and 35% to migrate out to the other regions for male and female respectively. Analysis of migration level showed the residents of Fukuoka prefecture at their age 20 were expected to live 42% for male and 54% for female of their remaining life in Fukuoka. The most popular destinations of migration were Southern Kanto for male and Kyushu region for female. As the results of multiregional population projection the peak pupulation of Fukuoka prefecture was estimated at 5.08 millions in the year 2005 and the highest proportion of age 65 and over was expected to exceed 20% slightly in the year 2020.
Over the period of 5 years 1976-1980, total of 4, 042 cases of accidental injuries serious enough to prevent the employees from their works at least 4 days occurred among the workers of six types of industrial enterprises, land carriage, forestry, tranportation, construction, manufacture and other business, under the jurisdiction of Kagoshima Labor Standard Office. In these cases, the number of those who had at least one accident was 3, 840, of whom 3, 646 was injured only once, 163 twice, 25 three times and 3 four times. Assuming that the distribution for the frequency of accidents per head of those who had at least one accident is a truncated Poisson distribution, the incidence rate of accidents for the hypothetical population at risk of accidents can be estimated by trial and error as the unknown parameter m of the equation y=m/1-e-m, where y is the average frequency of accidents per head of those who had at least one accident. We obtained here a value of 0.113 for all the industrial enterprises involved, the highest being 0.269 for forestry followed by 0.163 for construction and the lowest 0.064 was for manufacture. Thus, the number of working population at risk of accidents was obtained as a simple quotient of the total number of accidents divided by m, being 35, 799 for all the industrial enterprises involved, 4, 783 for land carriage, 1, 173 for forestry, 2, 009 for transportation, 3, 394 for construction, 13, 815 for manufacture and 17, 327 for the other business. If the total cases of accidental injuries are randomly derived from the workers at risk of accidents, then the distribution for the frequency of accidents per head containing the class 0 should conform to the complete Poission series. However, the fitted values for the Poisson distribution indicated a poor agreement which was born out by the high value of x2, the x2 was 64.21 on 2 degree of freedom for all the industrial enterprises involved, for which p<0.005. On the every year basis, however, the distribution for the frequency of accidents per a worker conformed to the Poisson series. From the facts described above, we may conclude that the industrial accident is an unusual event and every worker is not always equally exposed to the risk of accidents even in the same working condition.
In order to investigate the factor relating to the recent average life span (e0) in Japan, relationships between e0 and 21 items concerning food and tobacco were studied by annual transition and geographical distribution of items, and the following results were obtained. 1) In the time serial correlation coefficients between e0 (1965-'85) and 5-years foregone items (1960-'80), those with 13 items including milk were positive and significant, and those with 5 items were negative and significant. 2) In the geographical correlation coefficients between e0 (1985) and 6-years foregone items (1979), those with 3 items for men and 4 for women including milk were positive and significant, and those with 1 item were negative and significant for both sexes. 3) In the geographical correlation coefficients between changes of e0 (1985/'70) and those of 6-years foregone items (1979/'64), those with 11 items for men and 9 for women including milk were positive and significant, and those with 2 items for men and 1 for women were negative and significant. 4) The partial correlation coefficients were calculated between changes of e0 (1985/'70) and those of 6-years foregone items (1979/'64) whose coefficients were significant and agreed with each other in sign in the above 1) and 3) calculations. The coefficients with milk and coffee for men and milk for women were positive and significant. Above results suggest that milk intake relate to the recent average live span in Japan.