~14— result from a single vorief series of test explosions. The highest individual doce, therefore, could have been 30 times the averare, or 18.6 rets. Thus, it has been recognized th: iodine 131 represents a potentially important hazard from fallout, Until recently, considerations of this problem, with few exceptions, have been limited to iodine 131 exposures expected in the population as a whole during periods of active testing. This problem has been discussed in detail before the JCAE, and the >t. Louis Committee for Nuclear Information has reported on 16.0%rt has been recognized that rapid measurements of iodine 131 in milk provide a useful index of the radiation exposure to the thyroid expected in a child consuming the milk. While this type of information is therefore imp>rtent in estimating the iodine 131 hagard fro fallout it has certain limitutions. Nearly all available measurements of fodine 131 in milk are based on larje commercial supplies. fhese represent pooled milk from many widely scattered farms. Such measurements are, of course, valuable in estimating the iodine 131 intake of children who drink commercial milk of this type. However, the pooling ;rocess conceals variations in iodine 131 levels among separate regions and it is im possible to determine how much iodine 131 would be taken in by a child who consumes fresh milk directly from a cow or herd stationed in a particular local area. Nevertheless, the latter is the situation which governs milk consumption