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Periodic Table--Radium

Radium has 25 different isotopes, four of which are found in nature. 223Ra, 224Ra, 226Ra and 228Ra are all generated in the decay of either U or Th. 226Ra is a product of 238U decay, and is the longest-lived isotope of Ra with a half-life of 1602 years; next longest is 228Ra, a product of 232Th breakdown, with a half-life of 6.7 years. Since Ra is closely related to Ca, it has the potential for causing great harm by substituting for the latter element in bone.

Like radon, radium has been used in hydrologic studies as a chemical tracer in environments where mixing water masses have distinct radium concentrations. Because radium has several naturally occurring isotopes, differences in the isotopic ratios of radium can be used even where no difference in absolute amount of radium exists between water masses, or non-conservative behavior occurs. An additional advantage of radium over radon is its nonvolatile behavior, although it does tend to sorb onto particulate material more readily than does radon.

Studies using radium to solve hydrologic problems in catchment-size basins have been few compared to those in which radon was used to determine water from various ground water sources, but show great potential for further development. Several examples showing how radium has been used in catchment hydrology studies are provided by Kraemer and Genereux (1998) and Michel et al. (1982).

Source of text: This review was assembled by Eric Caldwell and Dan Snyder from the following references.

Bernat, M. and Church, T. M. (1989). "Uranium and thorium decay series in the modern marine environment." In: P. Fritz and J.-Ch. Fontes (Eds.), Handbook of Environmental Isotope Geochemistry, Volume 3, Amsterdam, Elsevier Science. pp. 357-384.
Bowen, R. (1988). Isotopes in the Earth Sciences. Elsevier Applied Science, New York, 647 pp.
Faure, G. (1986). Principles of Isotope Geology, Second Edition. John Wiley and Sons, New York. 589 pp.
Kraemer, T.F. and Genereux, D.P. (1998). "Applications of Uranium- and Thorium-Series Radionuclides in Catchment Hydrology Studies." In: C. Kendall and J.J. McDonnell (Eds.), Isotope Tracers in Catchment Hydrology, Elsevier, Amsterdam, pp. 679-722.
Michel, J., King, P.T., and Moore, W.S. (1982). "228Ra and 226Ra in drinking water: a new technique using gamma-ray spectroscopy and results from South Carolina", in Isotope Studies of Hydrologic Processes (Eds. E.C. Perry, Jr. and C.W. Montgomery), Northern Illinois University Press, DeKalb, Illinois. pp.83-90.
Miller, R.L., Kraemer, T.F. and McPherson, B.F. (1990). "Radium and radon in Charlotte Harbor estuary, Florida Est." Coast and Shelf Sci., 31: 439-457.
Volpe, A.M., Olivares, J.A. and Murrell, M.T. (1991). "Determination of radium isotopes ratios and abundances in geologic samples by thermal ionization mass spectrometry." Anal. Chem., 63: 913-916.
Related Links
Periodic Table
Fundamentals of Stable Isotope Geochemistry
General References
Isotope Publications
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