Suicide mortality of young, middle-aged and elderly males and females in Japan for the years 1953-96: time series analysis for the effects of unemployment, female labour force, young and aged population, primary industry and population density.

Effects of nine social life indicators on age-adjusted and age-specific annual suicide mortality of male and female Japanese population in the years 1953-96 were investigated by multiple regression analysis on time series data. Unemployment rate was significantly related to the age-adjusted mortality in both males and females. Also, female labour force participation was positively related to the male mortality; persons and 65 and above was inversely related to the male mortality. Results on the age-specific mortality indicated that: during the 44 yr, (1) unemployment significantly related with the mortality of young, middle-aged and elderly males and young females; (2) female labour force participation significantly related with the mortality of young and elderly males and young females; aged population significantly related with the mortality of middle-aged and elderly males; (4) young population significantly related with the mortality of young and middle-aged males and females; (5) divorce significantly related with the mortality of middle-aged and elderly males and young males and females; (6) persons employed in primary industries significantly related with the mortality in middle-aged males and young males and females; and (7) population density significantly related with the mortality of middle-aged males and young females.

Low income, unemployment, and suicide mortality rates for middle-age persons in Japan.

The relationships between age-specific suicide mortality rates and social life factors for all 47 Japanese prefectures in 1980, 1985, and 1990 were assessed by multiple regression analysis after factor analysis on 20 social life indicators. During this period, Japan experienced a secondary oil crisis in 1980-1983 and a bubble economy in 1986-1990. It was concluded that (1) low income was the major determinant which positively affected suicide mortality rate in middle-aged men during a previous 20-yr. period (1970-1990), (2) urbanization was negatively associated with male suicide mortality rates in most of the age classes in the 1980s, (3) unemployment was one of the major determinants of increased suicide mortality rate in middle-age men in the 1980s, and (4) unemployment was the major factor which was inversely associated with suicide mortality rate for elderly women from 1980 to 1990 in Japan.

Effects of urbanization, economic development, and migration of workers on suicide mortality in Japan.

The relationships between male or female age-adjusted suicide mortality and social life factors for all 47 Japanese prefectures in 1980, 1985 and 1990 were investigated by stepwise multiple regression analysis after classification of 20 social life indicators by factor analysis. During this period, Japan experienced the second economic crisis (the so-called secondary oil crisis) in 1980-1983 and economic prosperity (bubble economy) in 1986-1990. In all the three years, male suicide mortality was significantly related inversely to the urbanization and economic development factor, the result of which was consistent with the data in our previous study for the years 1970 and 1975. Similarly, the male mortality was positively related to the factor of migration of workers in the three years. No factor significantly related to female mortality for all the three years was found. It is suggested that (1) urbanization was a major determinant which prevented male suicide mortality during the past 20 years (1970-1990) in Japan; (2) migration of workers became an important factor for male suicide mortality during these 10 years; and (3) female suicide mortality was less vulnerable to social life factors for these 20 years than the male mortality.

Particulate matter and particle-attached polycyclic aromatic hydrocarbons in the indoor and outdoor air of Tokyo measured with personal monitors.

Using two types of personal monitors for suspended particulate matter of diameter under 10 microm (PM-10) and for particles of diameter under 1 microm with attached polycyclic aromatic hydrocarbons (PPAH), we measured the PM-10 and PPAH concentrations in the indoor and outdoor air in various locations in the Tokyo area. The major findings were as follows. (1) The PPAH concentrations in a clean living room increased rapidly within several minutes after one cigarette was smoked. (2) Using the average indoor concentrations of PM-10 and PPAH in a department store as control concentrations, respectively, where the average indoor PM-10 concentration was closest to an annual average outdoor concentration in Japan, the mean value for indoor air concentrations of PM-10 by location ranged from 2.2 to 6.2 times the control concentration, and the mean value for indoor air concentrations of PPAH by location ranged from 1.0 to 32.2 times the control concentration. (3) Using the same control concentrations, the mean value of outdoor concentrations of PM-10 by location ranged from 1.6 to 8.5 times the control concentration, while the mean value of outdoor concentrations of PPAH by location were up to 353.7 times the control concentration. The major polluted places were main traffic roads, highways, and street tunnels. (4) The correlation coefficient between the PM and the PPAH concentrations in the total monitoring time was 0.014, which was not significant (P>0.05).