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Environmental Health - Toxic Substances



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Graph - Tritium Concentrations
Tritium concentrations in the atmosphere. Image from USGS Circular 1213

Tritium - "A radioactive form of hydrogen with atoms of three times the mass of ordinary hydrogen; used to determine the age of water." - U.S. Geological Survey, 2007

Tritium - "Tritium is principally of interest to the hydrologist as a water-dating tool and as a tracer, introduced either naturally or artificially, for investigating ground-water hydrodynamias in areas of relatively rapid flow." - Thatcher and others, 1977

Tritium - "Tritium exists fairly uniformly in the environment as a result of natural production by cosmic radiation and residual fallout from nuclear weapons tests ... Naturally occurring tritium is most abundant in precipitation and lowest in aged water because of its physical decay by beta emission to helium. The maximum beta energy of tritium is 0.018 MeV and its half-life is 12.26 years." - Eaton and others, 2005

Tritium - "In a manner similar to 14C production, 3H is produced naturally in the earth's atmosphere by interaction of cosmic-ray-produced neutrons with nitrogen. Lal and Peters (1962) estimated that the atmospheric production rate is 0.25 atoms/s cm2. In 1951, Van Grosse and coworkers discovered that 3H occurred naturally in precipitation. Two years later large quantities of man-made tritium entered the hydrological cycle as a result of large-scale atmospheric testing of thermonuclear bombs." - Freeze and Cherry, 1979

USGS Information on Tritium

Related Science Feature Articles


American Geological Institute, 1976, Dictionary of geological terms (4 ed.): Garden City, New York, Anchor Press, 472 p.

Eaton, A.D., Clesceri, L.S., Rice, E.W., and Greenberg, A.E., 2005, Standard methods for the examination of water and wastewater: American Public Health Association, 1368 p.

Freeze, R.A., and Cherry, J.A., 1979, Groundwater: Englewood Cliffs, New Jersey, Prentice-Hall, 604 p.

Thatcher, L.L., Janzer, V.J., and Edwards, K.W., 1977, Methods for determination of radioactive substances in water and fluvial sediments: U.S. Geological Survey Techniques of Water-Resource Investigations, Book 5, Chapter A5, 95 p.

U.S. Geological Survey, 2007, USGS NAWQA glossary: U.S. Geological Survey, access date August 13, 2010.


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