摘要：The activity concentrations of 241Pu and the 241Pu/239+240Pu activity ratios were determined from environmental samples to complete the study of transuranium nuclide distribution in environment in Finland. The activity of 241Pu was determined by measuring the activity of its decay product, 241Am, using α-spectrometry. The activity concentrations of 241Pu in lichens from 1967–1976 were from 2.3 to 93 mBq g–1 (in the sampling year) and from < 0.7 to 686 mBq g–1 in lichen, peat, and grass samples from 1986 (on 1 May 1986). The 241Pu/239+240Pu activity ratios for the corresponding samples were from 4.1 to 167. The comparison of the 241Pu results obtained in the present study and those from earlier analyzes (liquid scintillation counting) indicated a fairly good agreement. Regression analysis indicated that the activity concentrations of mainly Chernobyl-derived nuclides 238Pu, 241Pu, and 242Cm correlated significantly with each other in the samples of 1986, the r2 values being 0.89 and 0.67 for 241Pu/239+240Pu vs. 238Pu/239+240Pu and 242Cm/239+240Pu vs. 241Pu/239+240Pu, respectively.
