Changes in biological status of the Jastarnia population over the last 20-year period.

The objective of this paper is to analyze changes in the biological condition of the inhabitants of Jastarnia (Hel Peninsula), who were examined three times during 1963-87. A total of 1791 persons of both sexes, aged from 3 to 80 years were under study. A total of 20 somatic and physiological traits were considered. According to the data of the Central Statistical Office (available from 1976) the birth rate in Jastarnia increased in 1987 but mortality increased even at a higher rate so that the increase of the population (per 1000 inhabitants) was reduced from 6.8 in 1976 to 3.7 in 1987. A factor analysis, used to estimate socio-economic conditions of two generations of this town, has shown that the apartment size and income of a family (factor 1) explained the highest percentage of the variance of the traits considered. Education of parents was on the second position (factor 2). The next factor (3) represented biological properties of parents measured by their stature. The last one (factor 4) characterized family size in the second generation, for the first generation this trait being related with factor 2 (culture). A tendency to slim body was observed in children and youth. However, the ratio of chest circumference to stature (Marty index) did not change, which can be explained in terms of the adaptation to maritime climate. The content of adipose tissue increased in children and youth, and also the vital capacity of lungs in relation to stature (Ziemssen index) increased in children. Blood pressure at rest was reduced in 1987, but systolic blood pressure at work was increased. An increase in the minute respiration rate and reduction of chest extension in the contemporary youth seem to be rather unfavorable.