| Popis: |
A determination was made of Sr/sup 90/ activity levels for the major surface waters of the U. S. From these values, it was calculated that the average runoff of Sr/sup 90/ amounts to 4 curies/day, corresponding to 0.5 mc/sq mile/ year, or 190 nu nu c/sq mile/year. The total gross fall-out contribution was calculated as 23,900 curies/day, of which 408 curies/day is found in runoff. The current maximum permissible concentration level of Sr/sup 90/ in drinking water for an uncontrolled area is 100 nu nu c/1, one-third of which was suggested as the average concentration applicable to the entire population, Food, not water, is the major source of Sr/sup 90/ intake; water may be responsible for approximately 10% of the ingested Sr/sup 90/. In places where cisterns are used for water supply, the Sr/sup 90/ from water is approximately 35 to 50% of the total intake. (B.O.G.) |
