Radioactivity of people and milk: 1957

Ultralow-cost portable device for cesium detection via perovskite fluorescence

Public anxiety and concern from cesium pollution in oceans have been back on the agenda since tons of nuclear waste water were announced to be poured into oceans. Cesium ion can easily enter organisms and bioaccumulate in animals and plants, thus its harm is chronic to humans through food chains. Here we showed a kind of hybrid ionic liquid membrane (HILM) for detection of cesium ion in seawater through CsPbBr₃ perovskite fluorescence. With sustainability in mind, HILM was built frugally. The lowest cost of HILM is below 3 cents per piece. The HILM can detect cesium ion quickly with eye-readable fluorescence signal. Ultracheap, portable, easy-to-use on-site detection device could offer benefit for personal security and applications in environment science and ecology in the future decades.

Strontium-90 and cesium-137 in North American milk

The strontium-90 and cesium-137 concentrations in powdered milk in North America vary roughly with the specific activity of rain. The Sr(90)/Cs(137). ratios in over 800 powdered milk samples taken from 60 stations in North America from 1957-60 have a standard deviation of only 44 percent.

Ratio of Cesium-137 and Strontium-90 Radioactivity in Soil

The similarity in genesis and the more pertinent physical characteristics of fission-produced Cs(137) and Sr(90) suggests the use of the first as a convenient monitor for the other prior to uptake in the biosphere. Results are presented which indicate the feasibility of this approach in the case of soils.

Average Potassium Concentration of the Human Body as a Function of Age

Potassium-40 measurements on 1590 males and females ranging in age from less than 1 year to 79 years show sex differences and age trends in the ratio of muscle mass to the mass of other body constituents. A difference first at approximately 12 years of age. While females show a continuous decrease in potassium concentration, males show a rapid increase between the ages of 14 and 16. During adult life both sexes show a persistent and parallel decrease, which may be related to physiologic aging.