Environmental radioactivity: experience from the 20th century } trends and issues for the 21st century

Environmental radioactivity has been an important area of research throughout the 20th century, with recent work having been stimulated mainly by: i. the remarkable power of radionuclides as tracers of the rates and mechanisms of environmental processes and ii. the potential health implications of contaminant radionuclides in the environment. A review is presented of salient aspects of environmental radioactivity, including consideration of tracer applications, sources and environmental impact of anthropogenic radionuclides, radioactive waste disposal and future exploitation of nuclear energy.