Thorium series radionuclides in the environment: Measurement, dose assessment and regulation

Environmental radioactivity research is more advanced for the 238U series than for the 232Th series, for a number of reasons. One reason is that some radionuclides of the 232Th series are more difficult to measure than the corresponding isotopes in the 238U series, and measurement techniques are less widely available. The 232Th series population doses, however, are sometimes significant. This paper analyses some main radionuclides in the 232Th series in comparison with corresponding nuclides in the 238U series, with regard to measurement techniques, dose coefficients and regulation needs.