the fraction of hit cells responding quantally at each cell dose point on the distribution obtained with LLE only, are shown as at in distributions within the larger ones. distributions yleldas the quantally, for each of The area under each of the smaller total fraction of exposed cells responding the expusures marked E-1, E-2, and E-3. It is this fraction, of exposed cells responding quautally for a given amount of exposure, that is actual result In the end product of the risk evaluation. the given cellular system, i.e., [It the excess is the total incidence, that system, of transformed cells resulting from the given exposure. a value can be obtained in this manoer for any amount of exposure in Such to a radiation of any LET, or mixture, without any requirement to utillze the “Linear, non-threshold” function required in the currently used approach, However, it may he useful to show how the proposed approach can be tied into, but differs from the present system. Fig. & This {is illustrated in The linear curve in the left hand panel permits one to determine the number of hit cells, or the risk of a cell oeing hit, for a given PT { t |? | | | wl ¢=] | |j | | or | & *; fo lq rd ~ | |{ | ! tions. HSEF * | | DienE) j# ne 3 2 | AREA# Iq Le a Fig. 6 Schematic plot showing the use of a normalized z distribution. Multiplication of this distribution by the nit size 16° HSEF permits one to estimate the fraction of cells responding quantally (solid circle on the curve marked T, in the left panel), from the fraction of cells hit and dosed (open circle on the curve marked F), . a + . 2 product6s — -217- Bea's BE tad ta the much Staller 5012919