Footnotes
[1]The biosphere is the living world, the sum of all living, interacting organisms.
[2]Symbiosis is a condition in which two organisms or communities of organisms live together in close association, either on a basis of mutual benefit or of benefit to one only, with or without harm to the other.
[3]Ionizing radiation is radiation that can cause damage to biological tissues.
[4]Isotopes are variant forms of atoms of the same element.
[5]Nuclides is a term used to describe all the forms of all the atoms. Radionuclides are radioactive nuclides.
[6]An ecosystem is a natural community, taken as a whole, including all biological and environmental factors.
[7]Ecologists are scientists concerned with the interrelations of organisms and their environments.
[8]A thermonuclear device is an explosive, such as a hydrogen bomb, based on a fusion reaction. In other atomic weapons the energy is derived from nuclear fission.
[9]The living organisms.
[10]Plankton are the floating, minute plants and animals that live in the sea (and also in fresh water), including diatoms, algae, protozoans, and crustaceans.
[11]For more on this program, see Plowshare, a companion booklet in this series.
[12]The half-life of a radioactive element is the time required for half its atoms to lose their radioactivity.
[13]Atmospheric tests of nuclear weapons through 1962 produced a fission yield equivalent to 191 million tons of TNT and introduced about 10.01 megacuries of strontium-90, for example, as fallout entering the environment.
[14]Floating one-celled animals.
[15]A picocurie is one trillionth of a curie; a curie is the basic unit of intensity of radioactivity, approximately equal to that in 1 gram of radium.
[16]For more about these studies, see Fallout from Nuclear Weapons Tests, a companion booklet in this series.
[17]Information on this research is found in Radioactive Wastes, a companion booklet in this series.
[18]The lake, drained in 1955, makes an interesting natural basin in which residual radionuclides are used in studies of mineral cycling.
[19]A roentgen is a unit of exposure to radiation, measuring the alteration of the atoms (ionization) of the radiated tissues. The rat dosages compare with recommended limits of exposure to man-made radiation for average individuals in human populations of an amount that approximates 0.5 roentgen per year.
[20]The area where highest readings were obtained in the survey. These studies are described in more detail in Whole Body Counters, a companion booklet in this series.