CORRELATIONS BETWEEN SOIL PARAMETERS AND RADIONUCLIDE CONTENTS IN SAMPLES FROM BISCAY (SPAIN)

The distribution of gamma emitting radioactive constituents in Biscay soils have been measured in 15 cm cores, at three depth levels, in fou rteen sampling positions. Analyses were performed in Marinelli beakers with a gamma multichannel analyser provided with a Ge-HP detector. Ad ditionally, each soil was characterized by a number of parameters (pos ition, bulk density, pH, size distribution, total contents of carbon, nitrogen and hydrogen, thermogravimetric data and major cations solubl e in ammonium acetate at pH 7). Seven natural radioisotopes (K-40, Ac- 228, Bi-212, (TI)-T-208, Ra-226, Pb-214 and Bi-214) and Cs-137 were de tected and measured. Relations between natural radionuclides (located before and after radon isotopes in both radioactive series) and soil p arameters are mainly explained by two statistical multivariate methods (factor analysis and numerical taxonomy). The more complex dependence of radiocaesium contents on soil characteristics was elucidated by li near multiple regression.