ABSTRACT
The radiochemical and radiobiological effects of nuclear radiation of man-produced nuclides are principally not different from those of natural radioactivity. As sources of radioactive radiation caused by man, one can assess a wide range of nuclides which differ in half-life, specific activity, kind and energy of emitted radiation, and physico-chemical and physiological behavior. The reactor accident at Chernobyl on April 26, 1986, led to the largest contamination of the environment of all known accidents in nuclear power plants until that date. The introduction of radioisotopes into the biogeochemical cycles by man via energy production starts with mining, not only of uranium and thorium, but also with the minor contribution of coal. For agricultural applications, mostly enclosed radionuclides are used, example, neutron probes for the determination of soil moisture in irrigation optimization. The sea and the lakes receive most of their artificial radioactivity by precipitation.
