(1975) have studied the uptake and tissue distribution of Pu by cattle. On one cow which was confined solely to the contaminated area for 177 days, the total intake of Pu was about 100 U Ci/day. They found no lesions not encountered in cattle on similar noncontaminated ranges. The skeletal tissue of the 177-day cow con- tained 24 times the background amounts in cattle elsewhere, 9.5 times the amounts in muscle tissues of cattle elsewhere, the liver, 260 times the background amounts. and in The total content vas 238 pCi in a liver from this animal weighing a little more than 6 kg. In brief, conditions around NTS can be summed up as follows: In several areas within NTS, there are relatively large amounts of Pu contaminating the soils. This condition has existed for up to 20 yrs, during which time the Pu, thought to be primarily in the oxide form, has migrated to a few centimeters depth in the soils on NTS proper and to greater depths in other test areas. Within soils Pu appears to be associated with the silt fraction, with a low solubility. It has been moved by wind and weather in a redistribution pattern which now shows most of the Pu associated with the soils adjacent to, and under, shrubs and shrub clumps. The amounts of Pu moved by winds have been reduced sharply 38during the time since the tests. Wind movement and redistri- bution appear to result from saltation of larger soils particles which may not be carried to an altitude more than a meter above the surface, and which, when they strike the surface, dislodge smaller Pu particulates by an avalanching effect; and these smaller Pu particles may be more readily airborne. With distance, however, Pu-air concentrations decrease very rapidly. Plants growing in the Pu-contaminated areas have Pu contaminating their surfaces and likely have small amounts within their tissues from uptake from their roots and possibly from surface absorption through aboveground tissue. Cattle, restricted in their food to grazing these areas, have Pu in their tissues within a few 10's of times background values except in liver, where the concentration reached 260 times background. 173