discusses the environmental contamination that has resulted from nuclear weapons
testing and accidents, and how discharges from current uses are being controlled.
We have seen in Chapter 7 that natural radionuclides pervade our environment. This chapter deals with the artificial radionuclides that have
been widely dispersed by events such as tests of nuclear weapons in the atmosphere and the Chernobyl accident and by the deliberate discharge of radioactive wastes from nuclear and other installations.
Such radionuclides find their way from air and water onto the ground and into foodstuffs and so deliver radiation doses in various ways to human beings.
Nuclear weapon tests
When nuclear weapons were tested above ground, they propelled a variety of radionuclides from hydrogen-3 (tritium) to plutonium-241 into the upper atmosphere. From there, the radionuclides transferred slowly to the lower atmosphere and then to the Earth’s surface.
Around 500 atmospheric explosions were conducted before the limited test ban treaty was enacted in 1963, with a few more until 1980. The concentrations of radionuclides in air, rain and human diet are now much lower than the peak values in the early 1960s.