Chapter 9 



ACCUMULATION AND RETENTION OF RADIOACTIVITY FROM FISSION 

 PRODUCTS AND OTHER RADIOMATERIALS BY FRESH- WATER 



ORGANISMS^ 



Louis A. Krumholz, Department of Biology, University of Louisville, Louisville, Kentucky 



and 

 Richard F. Foster, Biology Operation, Hanford Laboratories, General Electric Company, 



Richland, Washington 



Introduction 



Relatively little is known about the mech- 

 anisms of uptake, concentration, retention, and 

 excretion of fission products and other radio- 

 materials by fresh-water organisms. These or- 

 ganisms include many biological forms such as 

 the vascular plants, algae and phytoplankton, 

 protozoans, zooplankton and other invertebrate 

 forms, and representatives of each of the five 

 vertebrate classes. 



The complex interrelationships of the fresh- 

 water biota, together with their diverse indi- 

 vidual anatomies, physiological processes, and 

 life histories indicate the enormous scope of the 

 problem of determining the role of radioma- 

 terials in the metabolic processes of such a 

 community. In addition, there is extreme ur- 

 gency for obtaining information on many as- 

 pects of this problem within a relatively short 

 period of time. Within the next 10 years sev- 

 eral power-producing reactors will undoubtedly 

 be in operation ; many placed, in all probability, 

 near the large industrial and/or population 

 centers of the United States where the only 

 ready means of disposal of large quantities of 

 liquid effluent will be into fresh waters. Any 

 near-by rivers and lakes may be subject to 

 rather severe contamination by radioactive ma- 

 terials in the event of accidents. 



Owing to the complex interactions of the 

 factors involved, any estimates of the levels of 

 radioactive contamination that may occur in a 

 particular situation may be in error by as much 

 as one or two orders of magnitude. For purposes 

 of hazard control, estimates must therefore be 



1 Contribution No. 10 (New Series) from the De- 

 partment of Biology, University of Louisville. 



based on pessimistic assumptions with the hope 

 that field sampling and experimentation will 

 reveal a more desirable situation. 



An estimate of the worst situation can be ob- 

 tained by comparing the concentration of a par- 

 ticular element in the water with its concentra- 

 tion in an organism or tissue under study. Since 

 the radioisotope of the element will behave in 

 much the same manner as its stable counterpart 

 (for purposes of this paper), there will be no 

 greater concentration of the radioisotope than 

 of the stable form. 



Sources of information 



At the present time there are three primary 

 sources of information available regarding the 

 uptake, concentration, retention, and excretion 

 of radiomaterials by fresh-water organisms. 

 They are: 



1 . The long-term program of the Biology Labo- 

 ratories of the General Electric Company at 

 Richland, Washington. This program has been 

 primarily concerned with the accumulation of 

 radioactive materials in the flora and fauna of 

 the Columbia River. The effluent water released 

 to the Columbia from the plutonium-producing 

 reactors at the Hanford Operation contains ra- 

 dioelements induced when the "impurities" in 

 the cooling water pass through the high neutron 

 flux. The Hanford program was designed as a 

 radiological-ecological study with four main ob- 

 jectives: (1) to determine the geographical dis- 

 tribution of the radioactive materials, (2) to 

 find out how the radioisotopes became dis- 

 tributed in the various kinds of aquatic organ- 

 isms from the phytoplankton on through the 

 fishes and, to some extent, to the land animals 



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