145 i greater than those ovtained Ly the more conventional total alpna mathod. This difference arises because equation 1 is only an approximation. ing observed differences batnacn the cencentraticns computed using the rapid or conventional techniques and the spectrcmetric mathods are more rancor. These later differences inay arise from some combination of four main factors. The first is that alpha emitters other than those measured chemically are present in these contaminated sediments. Tne second is that because the milligram sized aliquots of the suspended ground-up sediments enalized are probably slightly inhomogeneously contaminated, deviations in the sample count rate which arise from unrepresentative sample aliquceting cannot be averaged out as was the case for the Eravo Crater "standard" samcle. Third, white the ccncentration fractionation in fcur samples was found to be constant for plutonium, fractionation of the other radioisotopes was not evaluated. The last factor is that of the errors inherent in the determination of the range of the alpha particles needed for calculations in the second method. Although this problem is resolvable by empirically determining the range of the alpha particles in each sample, as was done for the Bravo Crater standard sample, this procedure is tedious and is a major Probiem in the determination of the absolute concentration cf alpha emitters in solid samples.