in bone - the bone marrow - rather than to the entire bone TASS, as was calculated in the original rerort (7vo-140). In adopting this approach, we are following the recommendations of the ICRP (ICRP-11) and the arrroach of Spiers used by UNGCEAR (22), The following text considers the information available for estimating the doses to the fetus, the newborn, and children relative to adults, and ° also the dietary changes which are assumed for children. Dose to Fetus and Newborn Pelative to Adults YQ 2. The Sr/Ca ratio in the fetus and in mothers' milk is determined by Li 9 ov 9 kh ct oO oO a wo ty a) the Sr/Caratic in the maternal +biood. cci (on = {ES (EC Sr/Ca discrimination across the 1,2 ier and across the rammary gland is nearly the same.’ > : e785 Sr/Ca ratio of the fetus or newrorn is very similar to that of the . oon 4 - : , KH ry D Oo ct V Q 3 : human breast milk is in the ranse of 0.1 to 0.16.79? . ™— Oo bg re) et fog o> ct on yy Uy Oo There is considerable evidence to py mothers’ milk. The sane observed . S04 . ratio exists for the fetus and newborn relative to the adult diet. 1,2 This ratio has teen observed directly and can also be calculated from data which indicate | 1,6 that the average OR bosdy/ diet for adults is 0.25;~ when this is combined with a further discrimination of approximately a factor of 2 across the placental or rmarrary membrane, the range of values of O.1 to 0.16 for milk or fetus is cdtained. IV-3