L ‘months following years of heaviest testing a are very small amounts are taken up from the soil.) Areas of heavierrainfall consistently shdw higher levels of strontium ge: Milk is one of the beat indicators of strontini 90 in the fou. supply, yet ul the sate time it is one of the helior sources off galcium. Remember it is not just the amount ov strontium on ‘that is important but alee how much there i present in rela -tlonteca'vium, Jn fact the total diet has had rooyhly5 times @e Kreat a strontium 80/caleium ratio as did tilk slone? “Strontium 89 bas the same chemical propertirs aa strontiuin WW and will follow the same metubolic paths 1) is vreated:iq “much larger quantities than strontium 90 but produces less uf “us AURLIC HEALTH MCE, VOW Co oF RAPIOLGOICASHEALTH PHOTO ‘ & problei since it has a shorter half-life (65 divs) and emltg “beta particles with about one-half the enerey of those frou strontium tu and its daughter product. Fur these reasons the strontium8Y content in milk may peak at. clucs many tints that of strontium 90 during the periods fnuncdiintely followin nuclenr tests, yet the total radiation douse te the bone over | lifetime from strontium 4 may be only one-geccer or heas Unis and simple =the milk is merely poured into @ plastic containes » J) contrastanalysis of milk for stran- : fium WO say require weeks including fadiochemical Preparation of the sample. wat oats oy “ .. sures that have hitherto been cunsidered of prime interest for local fallout, However, the total potential duses that may be accrued will require the drinking of the milk over periods of weeks, Up-to-date techniques nnd equipment new permit a reinlively easy end carly surveillance of jodine 191 in the mitk supply providing an opportunily for whatever action may be appropriate (Figure 6). E. STRONTIUM 90 AND STRONTIUM 89 Background Information Strontium 90 has a half-life of about 28 years, Jt is selectively deposited in the bones. Chemically it is related vo calcium, This similarity has led to the use of the “strontium unit” defined as une picocurie (2.2 disintegrations per minute) of strontium 90 per gram of caleiann, Strontium YO may become aseuciated with foodstulls by surface contamination of plants or hy uptake of the strontiom 14 ‘Uhus in hecausg/ of meteorulogical fucturs and also the fact thal surface con -taminatiun contributes more to the total strontium 8 uclive, . “found in plant life than does soil uptale during these periods. (Incidentally, the cesium 187 content of plant lifeis even more dependent on surface conlaminition since ony Counting a sample of milk fur luding$3ty | The progedure |s quiek : and avt into the counter, During yenrs of relatively heavy fallout: surface contamination has aceounted fer the Liurger puut al. The: periods showing the highest umount of -trontiaamn 0 in the food supply have been invariably the springy and summer ar eee aiegree ee 2 pe etree FIGURE 6. ~ gO*from the soil. ot ae «the strontium activity in plants but in the alecnce of atmos: pherie nuclear testing the avenueof soil uptake predominates: + Nem le Tee aie cateeee gee . ? L that of strontium i! wv a wal ae The Data create About “Ooomillion curies of strontigin G9 tis) heen by atmospheric nucleny teats with about tiation euries 4 this being spread globally. The other 4 soillion curien fe quickly in wrens iecal tu the Ceding: sites Vo rinte, rough! 8-0 million curies of strontiiin WW have been ooposited globally leaving a calculated 6 million curios in the recion of the atime ' 4 phere below 100,000 feet (based on mengiiecoents using eraft and balloons)" with some additional omeounta above ty “Jevel. The discrepuney in total muambers os due in part) radiological decay of strontivin vO but ome ob ase of anes tainties in the estimates theniselves. As expected, the peak value of “stropticis omits” in od wie passed in dune of (69 (82 strontium ce ah dation