~ ae Health Physics Pergamon Press 1971, Vol. 21 (Dec.), pp. 815-820. Printed in Northern Ireland RADIONUCLIDES AND SELECTED TRACE ELEMENTS IN MARINE PROTEIN CONCENTRATES T. M. BEASLEY,* T. A. JOKELA and R. J. EAGLE Laboratory of Radiation Ecology, College of Fisheries, University of Washington, Seattle, Washington 98105 (Received 11 December 19703; in final revisedform 24 March 1971) Abstract—The concentrations of various trace clerments and radionuclides have been measured in marine protein concentrates prepared from surface feeding fishes. As with concentrates prepared from benthic fishes, the ?7*¢Pb-?!"Po pair are the most signif- icant radionuclides present. Concentrations of stable Pb, Co and Ag in certain concentrates are sufficiently high to contribute substantially to estimated current intakes of these clements. INTRODUCTION In 1967, the United States began an ambitious food-from-the-sea program to investigate methods of increasing the world’s protein supply. An integral part of that effort has been the development of a commercially viable fish proicin concentrate (FPC) which could be used as a protein supplement in the diet of humans. In an effort to minimize production costs, whole marine organisms are processed to produce a protein rich product (-~80°7 protein) having the consistencyofflour. ‘The major use of a successful /PC program would most probably be directed to alleviating the protem deficicncy which is now present in the diets of some 1.5 billion persons living principally in tropical and subtropical areas.” Fowever, a recent study conducted by Cornell University for the National Center for Fish Protein Coneentrates indicated a potential narket for several billion pounds of FP. as additives in the U.S. food industry.) FPC could be used to enrich commodities such as beverages, breakfast foods, canned meats and baked gouds. ‘Voday, there are vigorous research programs dealing with FPG production in sweden, Canada, France, Brazil, Germany, Morocco, Pakistan and Peruf, and it seens probable that such producis will ultimately play a role in alleviating protein deficiency in hivman diets, In a recent article, data were presented on the concentrations of natural and artficial racionuchdes mi selected sceaioods and PQ, We reasoned that the concentrates would be particularly mteresting. since the industrial concentration of fish to concentrate (6.6 lb of wet fish produce | fb FPG) might enhance the concentrations of radionuclides if they were not removed in processing. Indeed, the concentra- tions of naturally occurring *°Pb (Ty. = 21.49) were sufliciently high to constitute a significant source of intake to humans. However, the majority of these concentrates were produced from benthic fishes (hake, sole, flounder) and we considered it of interest to compare the radionuclide concentrations of those products with others prepared using surface feeding fishes as starting materials. In addition, we have measured certain stable clements in these products as a further indication of the enrichment processes which occur in the chain: walter -organism-concentrate. METHODS The samples analyzed were supplied bv the National Center for lish Protein Concenirate, * Present address: Tnvironmental Sciences Branch, Division of Biology and Medicine, U.S, Atomic Encrgy Commission, Washington 1.C. 20545, ft A detailed description of both the basic FPG program and the associated research cffort to date is beyond the scope of the present article. There are, however, ro sources where sucn information can be obtained: ‘The Annual Report of the President to the Coneress on Marine Rescurces and Engineering Development (U.S. Government Printing Office: 1970) and Tish Protein Concentrate, A Comprchensive Biltiography (Clearinghouse for Federal Screntiie and Technical Information. National Bureau of Standards, U.S. Department of Commerce, Springficid, Va.). 815