Artificial and natural radionuclides present in environmental samples (Euca
lyptus wood and bark) can be transferred in an alkaline pulp mill and conce
ntrated in the recycling process. Some part of the radionuclides can be rel
eased into the environment associated with the discharges from such a facto
ry. An alkaline pulp mill located in the South of Spain was extensively sam
pled during 1993 and different radionuclides analysed in the collected samp
les. Thus the concentrations and fluxes of natural (K-40, Ra-226, Ra-228 an
d Th-228) and artificial (Cs-137 and Sr-90) radionuclides associated with t
he samples collected along the pulp production process are presented. It is
shown that radium and thorium radionuclides behave similarly to strontium
and calcium and, consequently, concentrate within the Ca-cycle. Furthermore
, K-40 and Cs-137 are concentrated during the Na-cycle, Finally, the result
s obtained by the authors are compared with the levels found in similar fac
tories, though situated in the North of Europe, by other researchers. (C) 2
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