* . . oo portation, Since a survey of all individuals* showed’ (hat “there was significant contamination ot skin and clothes, prompt decontamination was instituted. Clothes were removed and laundered. Their skin and hair were washed repeatedly with fresh water and soap. dn niuany individuals, perticwiarty om the Marshallese, it was difficult to wash the radioactive materniab from: the hair because of the heavy coconut. oil hair dressing used by these people. Table 1a EXPOSED AND CONTROL UNEXPOSED GROUPS Approximate Total Distance Effective Number in Group from Bikini (Naut. Miles) Time of Fallout Aincricans, Exposed Rongerik 2u tas H+ 6.8 hr : Americans, 105 Group Designation 3# Timeof Evacuation H + 28.5 hr (8 men) He 34 hr Instrument Readings Best Estimate Used in Dose Calculations of ‘Total Gamma Dose in Aira? 200 ur ‘he H+ 9 days TH 375 mr/hr H+ 7 days 175 100 mr/hr 69 (20 men) Control Kway American Marshallese, bxposed Rompedip 64 105 Ailuypinge 1B 83 Ulirik 157 Marshalicse, 270 H+4he H+ 4hr. H+ 22hr H+ 50hr (16 people) H+ 5thr (4B people) H + 54 hr H+ 9 duys Started at 40 mr/he H+ 55 hr Completed at H+ 78hr H + 8 days 14 117 Control Majuro Group Total Exposed - 267 Total Controls~ 222 *See Section 1.4.3. 1.4 ESTIMATION OF WHOLE BODY EXTERNAL DOSE The estimated values of external dose given in Table 1.1 were based on readings of AN PDR-39 field instruments. Averages of a iumber of dose rate measurements on each island at a given time were used. The readings were takenin air, approximately 3 feet above ground, several days after the inhabitants were evacuated, Before this time, adequate surveys with well calibrated instruments had not been possible. Several variables which influence the results are indicated below. These will be discussed in greater detail in an addendum report on external dose, which will contain the data, methods ind calculations by which the external dose analysis was made. 1.4.1 Energy Distributionof theFalloutGammaRadiation,ItsVariationWithTime, the Response of the Meter inEach“EnergyRegionaandits Correction Factorfor ‘the Total DoseSpectrum Fallout deposited as an effectively infinite plane source resulted in the dose-energy histogram shown in Fig. 1.2. Its energy distribution was the result of degradation of the original 16