Table IV. - (continued) Sea water!) PPM Sea foods, 2) edible portions PPM Fish muscle”) or soft parts PPM Concentration in fish muscle, median value Fallout radioisotopes B. Elements always present in man but of unknown function2) Silicon Aluminum Arsenic Nickel .02 - 4,0 .o .015 . 0001 <1<1 <1 - ? 40 40 12 10 180 490 “77 C, Other elements with isotopes of radiological interest Strontium Cesium Cerium 1) Sverdrup et al. (1946) 3) Vinogradov (1953) 2) * ** 13. Heinz Co.(1949 and 1958) Fukai and Meinke (1959) Chipman (1958) 002 0004 + ? 9 < ee 3 5+ g7 89, 90 Cgl37 Ce 141, 144