Simultaneous determination of232Th and238U in biological samples. Application to the estimation of their daily intake through diet

A simple method employing neutron activation and radiochemical separation was developed for simultaneous determination of the concentrations of232Th(Th) and238U(U) in biological materials. Using this method, it is possible to detect 0.05 and 0.2 ng of Th and U, respectively, in the samples. This method was applied to determine the daily dietary intake of these two nuclides by the population living in the high background areas of India (Monazite area), where the soil contains very high levels of these two nuclides. The comparison of the daily intakes by the population living in high and normal background areas showed significantly higher intake of these two nuclides by the high background population.