A field study of Ra accumulation in trout with assessment of radiation dose to man.
The purpose of this study was to determine the concentrations of 226Ra in edible fish from surface ponds near an open pit U mine. Because one reclamation plan for the U mine proposed formation of an artificial lake in the open pit, potential radiation dose to man from ingestion of fish needed to be investigated. Trout were collected from four existing ponds which varied in mean 226Ra concentration from 12-33 pCi/l. and in Ca concentration from 30-330 mg Ca/l. Radium and Ca accumulation in trout flesh, skin, fins and bone were measured. Geometric mean concentrations of 226Ra in trout flesh from four ponds ranged from 6.3-30 pCi/kg wet weight. The distribution of Ra in the trout body was similar to that of Ca. Of the total 226Ra in trout carcasses, 6% was in flesh, 25% was in skin, 28% was in fins, and 41% was in bone. Mean concentration factors for 226Ra in trout flesh from the four ponds ranged from 0.29-2.5. Bone concentration factors were up to 260 times higher than for flesh. Observed ratios (Ra/Ca in fish tissue divided by Ra/Ca in water) were used to normalize the differences in Ca availability among the locations. Observed ratios were higher in all tissues of fish which had been in the ponds for a longer time, indicating that 226Ra concentrations in fish may increase with continued exposure to the nuclide. The calculated dose equivalent commitment to human endosteal tissue ranged from 0.2-2 mrem per fish consumed, depending on the assumed dietary and environmental parameters. Neglecting the consumption of trout skin underestimated the ingestion dose from 226Ra by a factor of 5-10. Estimated annual dose equivalent rates to human endosteal tissue ranged from 1.0-83 mrem/yr for an individual who consumed one fish per week for a 50-yr period. The dose to man from ingestion of 226Ra in fish would not likely preclude the establishment of a recreational lake at this site.
D000818:Animals; D005507:Food Contamination, Radioactive / Q000032:analysis*; D006801:Humans; D008906:Mining; D011829:Radiation Dosage; D011850:Radioactive Waste; D011883:Radium / Q000378:metabolism*; D012487:Salmonidae / Q000378:metabolism*; D014337:Trout / Q000378:metabolism*; D014501:Uranium
D011850:Radioactive Waste; D014501:Uranium; D011883:Radium