Whole-body cesium 137 activity up to 4 years after the Chernobyl reactor accident in premature newborns, newborns, infants, and children.

Cesium 137 activity was measured after the Chernobyl incident in a whole-body radiation counter (4-pi-scintillation counter) in 85 premature and mature newborns (group 1), 174 infants and young children up to 2 11/12 years (group 2), and 48 children between 3 and 8 years (group 3) from Bonn (Germany) and surroundings. In 1987 the mean level of radioactivity in group 2, at 3.7 Bq/kg body weight corresponding to a mean radiation exposure of 11 muSv/y, was lower than that of group 1 (5.8 Bq/kg, 17 muSv/y) and 3 (9.4 Bq/kg, 28 muSv/y). Up to 1990 the values of all groups revealed a continuous decrease. The latest measurements showed mean values of 0.5 Bq/kg (1.5 muSv/y) in group 1, 0.6 Bq/kg (1.8 muSv/y) in group 2, and 0.8 Bq/kg (2.4 muSv/y) in group 3. A comparison with present cesium 137 values and determinations of the end of the 1950s and beginning of 1960s, both in adults, showed good agreement. The effective dose-equivalent rates amounted to less than 1% of that from natural radiation exposure. These levels should present no teratogenic risks to the population studied and, while there are theoretical mutagenic risks, the dose is so low that no increase in measurable mutagenic effects should be observed.

Age-Related Differences in Discounting Future Gains and Losses.

When asked to choose between immediate versus future gains, individuals tend to fast-track benefits and, congruently, they tend to delay costs. But, despite the ever-increasing importance of the topic, few studies have investigated this behavior among senior citizens. The handful of studies that have been conducted have led to conflicting results and focused on gains as opposed to losses. These conflicting results may in part be due to demographic confounds and the inherent variability that comes with aging. Here, demographic confounds and variability due to aging were minimized by studying three groups: middle-aged, unimpaired-older, and impaired-older adults. Participants were asked to choose between sooner-smaller and later-larger monetary rewards and losses. Results indicated that impaired-older adults discounted the future more than unimpaired-older adults. Interestingly, middle-aged adults discounted future gains at a similar rate to impaired-older adults, but discounted future losses less than impaired-older adults (and similarly to unimpaired-older adults). This may suggest that unimpaired-older adults have developed a compensatory mechanism that leads to more cautious, patient choices. We discuss these results in the context of the neurobiology and neuropsychology of aging and decision making.

[One year after Chernobyl. Cesium-137 levels in premature, newborn and nursing infants and in younger and older children of Bonn and environs]. / Ein Jahr nach Tschernobyl. Cäsium-137-Gehalt von Frühgeborenen, Neugeborenen, Säuglingen, Kleinkindern und Kindern aus Bonn und Umgebung.

From May to August 1987, 137Cs activity was measured in a total-body counter (4 pi counter) in 33 premature and mature newborns (group I), 40 infants and young children up to 2 4/12 years of age (group II), and 15 children between 3 and 6 8/12 years (group III), all from Bonn or its environs. The mean of measurements in group II, at 3.7 Bq/kg body-weight, was lower than that of group I (5.8 Bq) and III (9.4 Bq). Mean radiation exposure, calculated from these data, was 1.7 mrem/a for group I, 1.1 mrem/a for group II, and 2.8 mrem/a for group III. A comparison with present Cs values in adults and measurements made at the end of the 1950's and beginning of 60's showed good agreement. There were no significant differences, as regards Cs activity, between newborns or infants who had been formula-fed or breast-fed. The measured radiation exposure of the three groups is about 1% of natural radiation exposure. Thus, present-day results indicate that there will be no damage to health outside the natural scatter.