Radiostrontium movement in soils and uptake in plants

The entry of radiostrontium into the biosphere has been largely the result of the large-scale atmospheric nuclear testing that occurred before the U.S.--USSR moratorium on such testing. Radiostrontium, particularly 90Sr because of its 28-year half-life, is a radiological hazard and, unlike 137Cs, the other major radionuclide dispersed into the biosphere during the testing, is not strongly sorbed to soils. Thus radiostrontium can move rather freely in soils and contaminate our foodstuffs, via plant uptake, as well as our drinking water. Because radiostrontium concentrates in bone and bone marrow, incidents of bone sarcoma and leukemia are likely to increase as deposited 90Sr in soils is released to the plant food chain over subsequent years. This review critically evaluates the results of many international investigations of the chemistry of radiostrontium in the soil and of the factors that affect its availability to plants. This review is intended to be a source of information on what research has been done, how it was done, the reasons the investigations were initiated and continued, and the conclusions derived. Sufficient time has elapsed since the last major atmospheric nuclear testing (1961 and 1962) and since the contemporary publication of reviews during and shortly after the testing for some of the theories presented at that time to have been either verified or proven invalid. In many cases these ideas have been consolidated, and, although a majority of the initial hypotheses were correct, in some instances the hierarchy regarding which process was dominant was out of perspective for the particular environmental conditions