27 the average concentration in solution in the water column can be accounted for by using a simple equilibrium model in which remobilization involves the sediment in the top 2.5 cz (Woshkin 1980). 5.4 Comparisons with Other Locations It is useful to compare the situation at Enewetak with other locations where plutonium has been released to the marine environment. One of the most studied locations is at Windscale in the United Kingdom where authorized radioactive discharges are made to the Irish Sea from a nuclear fuel reprocessing plant. Since 1972 discharges of plutonium isotopes to the coastal waters have averaged about 100 Ci per month (ten times that in the dome). Since the first operations of the plant about 10,000 Ci of 73%+4°*py have been discharged, 9,000 of which reside in the bed of the Irish Sea east of the Isle of Man (Hetherington et al. 1975, Penreath et al. 1979). Measurements have shown that the discharged plutonium is rapidly removed to the sediments and that only a few percent of the inventory (as at Enewetak) remains in the water column. Within 10 km of the source, concentrations in the water column average about 0.7 pCi/L and concentrations in the sediments average about 40 pCi/g (dry) with values as high as 105 pci/g (dry) (Hetherington et al. 1975). These average concentrations exceed those at Enewetak, which are about 0.017 pci/t for lagoon water and 5.2 pci/g for lagoon sediments (Noshkin et al. 1980). . Low levels of plutonium are discharged into Bombay harbor from a nuclear facility at Trombay.. Here plutonium concentrations in the vicinity of the discharge point range from 0.004 to 0.02 pci/z in . seawater and from 0.4 to 29 pci/g in the suspended silt (Pillai et al. 1975, Pillai and Mathew 1976). A reprocessing plant at Tokai, Japan, discharges into the ocean where activity levels of ??°*#**pu as high as 0.017 pci/: have been reported offshore (Kurabayashi’' et al. 1979). . Thus, authorized releases in different parts of the world have produced concentrations of transuranics in the marine environment comparable to or in excess of those found at Enewetak. 5.5 Transuranics in Marine Foods Transuranics can be detected in marine organisms worldwide, in both salt and fresh water, due to global fallout from bomb tests. As would be expected, relatively high concentrations in marine organisms are found where there have been releases of transuranics (e.g., near _Enewetak, Bikini, Windscale, Bombay, or Tokai). Concentration factors in fish (1.e., the ratio of activity in a gram of fish to that in a gram of seawater from the same environment) vary considerably between-species and between samples of the same species taken from different locations. Among fish there is little evidence of any strong or consistent relation to trophic level. These issues, as well as the results of measurements taken on 4,200 fish from 14 atolls in the Marshalls, were summarized recently by Noshkin and co-workers (Noshkin et al. 1980). They found concentration factors at Bikini and Enewetak to be similar, ranging from 5 to 10 in the muscle tissue of fish at all trophic levels (2nd to Sth}. Mean concentrations My. Ty ta) fo aC) at Enewetak in the muscle tissue of mullet and surgeonfish (which are