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APPENDIX C ESTIMATED THYROID DOSES FROM "GLOBAL" WEAPONS TEST FALLOUT IN AREAS DOWNWIND FROM HANFORD Report prepared for the NAS/NRC Board on Radiation Effects Research Harold L. Beck Formerly, Director, Environmental Science Division USDOE Environmental Measurements Laboratory April I, 1999 176
Appendix C I. INTRODUCTION 177 The CDC-FHCRC study considered only fallout from weapons tests at the Nevada test site as a potential confounder using doses estimated from the NC] study~ on doses from I-131 from Nevada weapons tests. However, a concern was expressed by an NAS/NRC Committee that "global" fallout from weapons tests conducted outside the U.S. should also have been considered. The author of this report was asked to examine the literature and any available data and estimate the doses that may have been received by the population of counties downwind from Hanford from this "global" fallout. This report estimates the thyroid doses received by infants, children, teens, and adult males for each year of significant testing for three areas (Benson, Franklin and Adams Counties, WalIa Walla County and Stevens County, WA) and compares the results with the NCT results for these same counties for NTS fallout. Table ~ lists estimated fission yields for each month during the period 1952-63 when tests in the atmosphere were conducted at sites in the Northern Hemisphere other than the Nevada Test Site. The total number of tests was over 500. Additional tests were conducted by China in the 1970's, however, the additional yield, and thus additional fallout, was small compared to the fallout in the years shown and thus was not considered in this report. The fission yields shown represent the sum of the estimated yields from all tests conducted during the indicated month and are presented here only to indicate the months when significant fallout might have occurred over large areas of the world. The exact yields of many tests were not announced and the ratios of fission yield to total yield are classified but are estimated to be on average 50°/O. Thus the fission yields given in Table ~ should not be taken as highly accurate but rather as a good indication of the relative yields as a function of time. It can be noted, however, that the total of the estimated fission yields from all atmospheric tests is consistent with measurements of Sr-90 depositions
178 Review of the HTDS Draft Final Report AS can be seen from the Table, the total fission yield from these tests is over 150 MT compared to a total yield of about ~ MT from the approximately 80 tests carried out at the NTS. However, most of these tests were carried out at sites far from the U.S., primarily in the south Pacific at Bikini and Enewetok or in the Soviet Union. Furthermore, because most of the yield was from multi-megaton thermonuclear tests, it is estimated that about 80°/0 of the debris were injected into the stratosphere. For the approximately 20% of the debris injected into the troposphere, a considerable fraction was probably deposited locally or regionally, particularly debris from surface shots as opposed to air bursts. The amount of debris reaching various areas of the U.S. also depends on the location of the test site. The tests in the Pacific were conducted at latitudes fairly close to the equator while the tests in the Soviet Union were at fairly high latitudes. Troposphere fallout clouds tend to travel around the globe remaining primarily in the same latitudinal band. Finally, the deposition at any particular site depends primarily on whether or not rain occurred at the time the debris was overhead. Thus it is not surprising that, as will be shown, fission yield is only a very crude indicator of the fallout deposition in the U.S. Unfortunately, there is only a limited amount of actual data on fallout deposition at particular sites in the U.S., particularly for short-lived nuclides, and virtually none for I-131 deposition. Fortunately, however, data on actual T-131 concentrations is milk are available for some of the testing period. II. AVAILABLE DATA A number of potential data sources were reviewed including the Quarterly Fallout Reports of the USAEC Health and Safety Laboratory, Reports of Hearings conducted by the US Congress Joint Committee on Atomic Energy. Monthly reports issued by the Public Health Service, Environmental Monitoring Reports from the Hanford Site and selected literature sources. Data that was found that are relevant to this study are discussed below.
Appendix C 179 Milk: T-131 was measured in milk from a number of dairy farms in the counties adjoining the Hanford site for 1961 and 1962. These data, taken from the 1961 and 1962 Site Environmental Monitoring Reports3 and averaged by month, are given in Table 2. Note that the data indicate significant amounts of I-131 in milk in the summer of 1961, even though there were no weapons tests before September 1961! Note also that the levels in milk varied significantly from dairy to dairy, particularly in late 1962, probably reflecting differences in the amount of feed received from fresh pasture. Soldat~ indicated that on average only about 50°/O of the cows were probably on pasture during October and November. The Hanford Environmental Monitoring Report for 19584 also contains some information on I-131 in milk. However, it appears only 4 measurements were made at a single dairy farm, Riverview. The average of these four measurements was about 150 polio. No information was given on exactly when the measurements were made. The Public Health Service (PHS) starting in 1958 also measured I-131 in milky Only a limited number of sites (about 12) were sampled in 195S, and for many the sampling did not begin until July or August. The sampling network was expanded to about 60 sites in 1961 and 1962. Selected PHS data are presented in Table 3. Deposition: Unfortunately, no data on the deposition of I-131 is available, either for the Hanford area, or for other areas of the U.S. Soldat~ presents a few values for the I-131 concentration in forage during 1961 and 1962 from which one can infer the approximate deposition. However, beginning in 1957, the USAEC's Health and Safety Laboratory (HASL) began measuring Sr-89 deposition along with Sr-90 using pots and ion exchange columns.6 Although Sr-89 has a half-life of about 50 ~ as opposed to the ~ days for T- 13l, it should still be a useful surrogate for estimating the deposition of other short-lived radionuclides injected into the
180 Review of the HTDS Draft Final Report troposphere. Unfortunately, Sr-89 was not measured near Hanford. However, as shown in Table 4, the total annual Sr-89 deposition rate per cm of precipitation appears to be fairly constant over large regions of the country in any given year. Although, the data in the table are for the entire year for months when fallout occurred, data for months of heavy fallout exhibit the same general pattern. (Note that one cannot compare differences from year to year in Table 4 since the fallout occurred over different intervals). This is not unexpected since the debris clouds would be expected to have dispersed considerably by the time they reached the U.S. and it is well known that the primary mechanism for fallout far Tom the immediate test sites is from precipitation scavenging. Thus it should be possible to infer the deposition of Sr-89 near Hanford from these data and the monthly precipitation values from the counties near Hanford. A limited amount of data on Ba-140 (Half-life = 12 d) was available for three sites; Pittsburgh, Westwood, NI, and Richfield, CA.7 These data were used to corroborate the estimated relationship between Sr-89 and [-131 deposition. Finally, for years prior to 1957, the only deposition data available was from measurements from the HASE Gummed-Film Network. Unfortunately, the gummed-film data for 1954, 1956 and 1958 have not been re-analyzed as were the data for the years of NTS testing.8 However, HarIey9 presented estimates of gamma dose made using the raw gummed-fiIm measurements. While the absolute values are probably suspects, the relative annual estimates should still provide a reasonable estimate of the relative short-lived radionuclide deposition that can be used to estimate the fallout deposition in 1956 and 1954. Precipitation: The monthly precipitation for Benton, Franklin Adams, Walia Walia, and Stevens Counties taken from historical US Weather Service Records are listed in Table 5. The data for Benton, Franklin and Adams were averaged since the variations in monthly precipitation in these three counties were small. The
Appendix C monthly precipitation for Yakima and Kittitas Counties, which supply milk to the Hanford area, were similar to that for Adams, Franklin and Benton Counties. I-! 3 ~ Releases from Hanford: References ~ and 2 also provide data on the I-131 released from the Hanford stacks in 1958, 1961 and 1962. The average daily releases were I.2 Ci/d in ];958, 0.54 Ci/d in 1961 and 0.33 Ci/d in 1962. This information was used to estimate the Hanford contributions to the activity in milk values presented in Table 2. III. METHODOLOGY The basic methodology used to estimate the doses from I-131 near Hanford was as follows. For 1961 and 1962, the doses for Franklin, Adams and Benton counties were estimated directly from the measured I-131 in milk at farms near Hanford after first correcting the milk data for Hanford plant contributions. Since all three counties are part of the same milk shed and receive similar amounts of rain, the estimated milk concentration data was assumed to apply to all three counties and a single set of dose estimates was made for these three counties. (The doses for Yakima and Kittitas Counties, which are also part of the same milk producing area, would also be similar to those for Franklin, Adams and Benton due to the similar rainfall pattern). The Sr-89 depositions for 1957, 5S, 61 and 62 were then estimated from the Sr-89 depositions at sites in the western U.S. and the measured monthly rainfall for Hanford area counties. The ratios of the deposition for WalIa Walla county and Stevens County to Benton- Franklin-Adams were used to estimate the milk concentrations for those counties for 1961 and 1962 from the measured milk near Hanford. The calculated deposition in 1958 relative to 1961 and 1962 was then used to estimate the relative concentrations in milk for 1957 and 1958 for all three county areas. The Sr-89 deposition for 1956 and 1954 relative to 1958 was estimated from the
182 Review of the HTDS Draft Final Report gummed-fiIm data and the concentrations in milk were assumed to vary the same as the estimated deposition. Finally, the thyroid doses for each county were estimated using the same conversions factors from milk concentration to dose for that county used in the NCT study. Further details are discussed below. Estimated Fallout I- l 3 ~ in milk for Benton, Adams, Franklin Counties: The average annual I-131 concentration in milk for the three dairies sampled was 48 pCi/L in 1961 (see Table 2~. However, the average annual concentration based only on data during months of global fallout is 33 pCi/~. Based on the activities measured during the summer months prior to weapons testing, it is estimated that about 40°/0 or 19 pCi/L of the average annual activity in milk during months with fallout was from I- ~ 3 ~ released from Hanford. The Hanford Plant contribution probably varied from month to month depending on local meteorological conditions so that the estimated plant contribution is somewhat uncertain. The measured concentrations were highest for the Ringold dairy farm, reflecting a probably greater fraction of feed from fresh pasture, particularly during the fall months when fallout occurred. Therefore, the average annual concentration for milk from Ringold, reduced by 40°/0 (57 x 0.365 = 21 x 0.6 = 12 nCi- d/~), was adopted as the best estimate of the concentration in milk for 1961 for cows on pasture. For 1962, again, adopting the data from the Ringold farm as most representative of cows on maximum pasture, the total activity measured was 75 pCi/L or about 15% higher than in 1961. As discussed earlier, the T-131 releases from Hanford in 1962 were 0.33 Ci/d versus 0.54 Ci/d in 1961. Thus, on average one would expect a Hanford contribution of about 60% that for ~ 96 ~ or about 20% of the activity measured in Ringold milk in 1962. The concentration of I-131 in milk for 1962 for cows on pasture was thus estimated to be 0.S x 75 x 0.365 = 22 nCi-~. For 1958, only 4 measurements were reported, all for the Riverview farm. The average of 150 pCi/L' would correspond r
Appendix C lS3 to a milk concentration of about 55 nCi-~. However, the releases from Hanford during 1958 averaged I.2 Ci/d versus 0.54 Ci/d for 1961 implying a contribution from Hanford of about 15 nCi-~/L based on the 1961 estimate. The net contribution of 40 nCi-~/L, although highly uncertain, is in reasonable agreement with the estimate of 30 nCi-~/L adopted for this study based on relative Sr- 89 deposition. (See next paragraph.) Sr-89 Deposition for Benton-Adams-Frar~klin, Walla Walla and Stevens Counties: The Sr-90 deposition in each of the three sets of counties was estimated on a monthly basis by multiplying the monthly precipitation listed in Table 5 by a weighted average of the Sr-89 deposition per cm of rains at the following western U.S. sites where Sr-89 was measured: Seattle, Medford, Salt Lake City, Vermilion, Richfield, weighting by the inverse of the distance from each site. Only data for days with rain were used. The monthly estimates were then summed to provide an estimate of total annual Sr-89 deposition. For 1957, it was estimated that about 1/3 of the estimated Sr-90 deposition at the above western U.S. sites where Sr-89 was measured resulted from tests at the NTS during August and September and this contribution was not included. Also, the total deposition in 1962 through January ~ 963 was calculated but it was decided to use only the deposition through November ~ 962 for calculating milk concentrations. Most of the additional fallout occurred in late December and January when cows were not on pasture from high yield tests conducted in late December. I-131/Sr-89 deposition: It is generally accepted that the average residence time for fallout released into the troposphere is about 301. It can then be shown that on average about 21% of the I-131 and 63% of the Sr- 89 released into the troposphere will deposit before decay. Since the fission yield of T-13 1 is about 7 x that of Sr-89, one would thus expect on average an I-131/Sr-89 ratio of about 2.3. However, as mentioned previously, about 80°/O of the fission products were
184 Review of the HTDS Draft Final Report probably injected into the stratosphere where the average removal half time is about ~ to 1.5 years. One would then expect only about 10°/O of the Sr-89 injected into the stratosphere (i.e. about ~ HO of the total produced) to be deposited before decay. Almost all of the T-131 injected into the stratosphere would decay before being deposited. Thus the actual ratio of Sr-89 to I-131 expected on average to be about (0.21 x 0.2) x 7 / (0.63 x 0.2 + 0.! x 0.~) = I.5. This is of course a very rough approximation. The actual ratio will vary from test to test and site to site. The ratio at any given time will depend on the amount of debris injected into the stratosphere and variations in stratospheric residence time from season to season. It will also depend on variations in Sr-89 to T-131 deposition from site to site due to the fact that the T-131 is deposited over a period of less than a month while the Sr-89 is deposited over several months. However, since the annual Sr-89 estimates generally reflect the sum of fallout from a large number of tests and seasons, a ratio of about I.5 would be expected to reasonably reflect the annual average I-131/Sr-89. Furthermore, the limited data on Ba-140 deposition tends to confirm the estimate of I.5 as being a reasonable average. Ba-140 was measured at Westwood, NI and Richmond, CA during 1961. The average ratio over several months of data was 2.5. Ba-140/Sr-89 measurements at Pittsburgh and Richmond during 195S, again for several months of data, averaged 2.3. Since Ba-140 has a half life of 12 ~ versus ~ for T-13l, the expected Ba-140/Sr-89 ratio would be about I.5 times that of T-13l, implying an T-131/Sr-89 ratio of 2.4/~.5=~.6. Thus the Sr-89 deposition estimates were multiplied by I.5 to provide a rough estimate of the annual I-13 1 deposition. As will be shown later, these T-131 deposition estimates, are in reasonable agreement with the milk estimates based on comparable data from NTS. However, it is important to note that the absolute I-131 deposition estimates were not used to estimate doses. Only the relative Sr-89 depositions from year to year were used to estimate doses.
Appendix C 185 Relative Deposition in 1954 and 1956 versus 1958 from Gummed- fiIm: The data in Table 6 indicate that the relative deposition in 1956 relative to 1958 was about 0.4-0.6, about in the same ratio as the fission yields. However, the gummed film data for 1954 indicate a ratio of only about 0.2-0.4 that of 195S, much less than the relative fission yield. This is not exactly unexpected, however, since all of the tests conducted in 1954 were surface shots compared to only about 273 of the yield in 1958 being from surface shots in 1958 and 3/4 in 1956. Surface shots would result in a much larger proportion of the debris being deposited locally and regionally as opposed to globally. Since these particular gummed- fiIm data represent very crude estimates of short-lived fallout, and the data in Table 6 does not reflect variations from site to site due to variations in precipitation from year to year nor corrections for differences in stratospheric deposition from year to year that are known to be included in the annual estimates, it was decided to adopt a ratio of deposition for each year of 0.4 of the 1958 deposition, even though the value may be somewhat conservative for 1954. An improved estimate of the deposition for these years might be possible with a re-evaluation of the gummed-fiIm data as was done for the years of NTS testing, however, that was beyond the scope of the present assessment. At any rate, the uncertainty in overall deposition estimates for 1954 and 1956 is probably still no worse than a factor of 2-3, comparable to that for NTS deposition in these counties. T-131 milk concentrations for 1954, 1956, 1957 and 1958: The milk concentrations for each county for 1958 were estimated from the 1961 milk concentrations based on the relative deposition in 1958 versus 1962. However, since about 10°/0 of the deposition in 1958 occurred in February and March, before the pasture season, the 1958 milk concentrations were reduced by 10°/0 below this ratio. For other years, almost all the fallout occurred during the pasture season and thus the milk concentrations were assumed to vary directly as the estimated
186 Review of the HTDS Draft Final Report depositions. The assumption that the concentration in milk will vary in direct proportion to the deposition is not strictly valid since the interception of fallout by vegetation depends on the rainfall rate and fraction of feed from fresh pasture. However, over an entire pasture season encompassing many fallout events, the variations should average out and the approximation should be fairly reasonable. The relative milk concentrations inferred for 1958 versus 1961 and 1962 are consistent with the ratios of the concentration in milk at sites in the western U.S. measured by the PHS (see Table 3~. The relatively small variation in the PHS milk values over large regions is also consistent with the deposition estimates based on the Sr-89 data. The absolute concentrations from the PHS network sites are generally lower than those estimated for the Hanford area. This probably reflects the fact that each PHS measurement is an average over a large milkshed that incorporated cows that were not always on fresh pasture while the Hanford area estimates are based on a maximum fresh pasture scenano. Dose Calculation: The doses were calculated from the milk concentrations using average milk to dose conversions for each age group for each county inferred from the NTS doses (see Table 7~. The NTS dose per unit annual milk concentration for infants and children vary from year to year (Table 7) reflecting the fact that the age grouping will change depencling on the exact dates of the fallout. However, the present estimates use an average value. This may have introduced a small bias into the estimated doses for infants and children from "global" fallout. IV: RESULTS Table 7 provides the estimated "global" fallout doses calculated as described above for the three regions downwind! from Hanford. Benton, Adams and Franklin counties were combined since the deposition was essentially the same in these three
Appendix C ~7 counties. The NTS dose estimates are actually the estimates for Frar~klin County. However, the NTS dose estimates for all three counties are very similar. Walla WalIa was considered separately because of its significantly higher rainfall rate and much higher NTS fallout while Stevens County is included to indicate the doses further away from the Hanford site. Stevens County probably also can be considered to have similar deposition as Spokane County and probably supplied much of the milk for Spokane residents. The results shown in Table 7 indicate that the "global" fallout doses near Hanford were lower but of the same order as the doses from NTS fallout. Since the dose estimates given here are essentially ratios of the measured milk concentrations of fresh farm milk when cows are on pasture, they were compared with NTS estimated doses for milk from a backyard cow. These doses are similar to those for fresh milk consumed on the farm. For other classes of milk drinker, the relative global to NTS doses would be similar although the absolute doses would be lower. Note that the estimated doses in Table 7 are doses from ingestion of milk and do not include the small additional doses from other foods. The absolute I-131 deposition estimates given in Table 7 were not used to calculate doses. Only the relative depositions from year to year were used. It is, however, encouraging to note that the estimated T-131 depositions from global fallout relative to the estimated milk concentrations are in concordance with the same ratios for NTS fallout where the milk concentrations were calculated directly from the estimated deposition. This indicates a measure of self-consistency that supports the validity of the methodology used to estimate the milk concentrations and resulting doses. As discussed previously, the exact ratio of milk concentration to deposition will vary somewhat due to variations in the amount of feed from fresh pasture and variations in the interception of fallout by vegetation. The estimated I-131 depositions for 1961 and 1962 are also in reasonable agreement with the limited data on I-131 concentration in fresh forage
188 Review of the HTDS Draft Final Report reported by Soldat in reference 3, using mass interception factors reported in reference I. The i- ~ 3 ~ thyroid doses from NTS fallout were estimated to have uncertainties of about a factor of 3-4. Most of this uncertainty was from the estimate of fallout deposition, which was based on interpolation of the sparse data from the gummed- fiIm network. The "global" fallout estimates for 1961 and 1962, being based on actual data are probably less uncertain, probably no worse than a factor of 2. The doses for 195S, based on the relative interpolated Sr-89 deposition are also probably less uncertain than the NTS with the 1958 to 1961/1962 ratios being accurate to about +/- 50°/O. However the uncertainty in dose estimates for 1958 is of course correlated to the uncertainty in the 1961, 1962 milk data and assumes the same ratio for deposition to milk concentration. Finally, the 1956 and 1954 estimates are more uncertain, perhaps as much as an additional factor of 2. Since the same factors were used to convert from milk concentration to dose for both NTS and global fallout, any error in this conversion (other than as discussed for infants and children) would be about the same for both fallout sources. Thus, one concludes that considering the uncertainty in both the NTS and "global" fallout dose estimates, the differences between the two sets of dose estimates are probably not statistically significant. it is interesting to note also that on the basis of the observed milk data from Hanford, the doses to the population around Hanford from site releases were a significant fraction of those from fallout in these same years. The dose estimates in Table 7 may be compared to the population-weighted estimate for the 50-60 degree latitude band of the Northern Hemisphere estimated by UNSCEAR2 of T.6 mSv from all weapons fallout. This estimate is of course a very rough average, which assumes uniform deposition of I-131 over the entire latitude band. The Hanford area would be expected to have lower doses than the average due to the significantly lower average precipitation, but higher due to being relatively closer to the test sites in the Pacific.
Appendix C ~9 Finally, it should be kept in mind when comparing these to doses from the Hanford HEDR Study, that persons exposed as infants in 1946, i.e. those with the highest doses, would have been exposed to NTS and global fallout as teenagers. Infants exposed to global fallout would of course not have been exposed during the major releases from Hanford.
190 Table 1. ESTIMATED FISSION YIELD* Review of the HTDS Draft Final Report Month MT Month MT Nov-52 0.9 Feb-58 1.4 Mar-58 0.4 Mar-54 8.7 Apr-58 0.0 Apr-54 3.6 May-58 1.2 May-54 5.3 Jun-58 5.7 Jun-54 0.0 Ju1-58 5.8 Ju1-54 0.1 Aug-58 4.3 1954 Total 18 Sep-58 1.1 Oct-58 5.8 May-56 3.7 Nov-58 0.0 Jun-56 0.9 1958 26 Ju1-56 6.5 Aug-56 0.5 Sep-61 3.0 Sep-56 0.6 Oct-61 6.0 Oct-56 0.0 Nov-61 11.0 Nov-56 0.0 Dec-61 0.0 Dec-56 0.4 1961 Total 20 1956 Total 13 May-62 2.0 Sep-57 0.4 Jun-62 3.0 Oct-57 2.3 Ju1-62 8.0 Nov-57 0.6 Aug-62 8.0 1957 Total 3 Sep-62 9.0 Oct-62 20.0 Nov-62 13.0 Dec-62 11.0 1962 Total 74 * NTS tests not included Source: Reference 2 and unpublished data.
Appendix C Table 2. Hanford Milk Measurements (pCi/L, average for month) 191 Ringold Riverview Benton Eltopia Mesa mean J 1961 28 <50 <50 ND ND <50 F 17 <50 <50 ND ND O M <50 <50 <50 ND ND 17 A 33 43 <50 ND ND 27 M 42 37 25 ND ND 33 J 52 30 21 ND ND 36 J <50 ND <50 ND ND <50 A <50 <50 <50 ND ND <50 S 47 58 <50 ND ND 40 O 357 67 120 ND ND 180 N 34 98 312 ND ND 150 D 16 9 13 ND ND 17 Annual 57 37 48 ND ND 48 Average Estimated 23 15 19 19 Hanford Contribution - J 1962 5 3 2 ND ND F M A M A S o N D 3 4 6 2 2 1 2 30 4 29 12 109 76 344 277 3 12 8 10 2 23 14 58 38 32 11 23 52 43 31 23 2 4 5 17 72 17 113 177 283 31 6 12 261 10 3 16 12 62 90 190 71 Annual 75 16 16 41 45 39 Average Estimated 15 3 3 8 9 Hanford Contribution
192 Review of the HTDS Draft Final Report Table 3. PHS Milk Data, Average Annual Concentration (pCi/L) 1958 1961 1962 58/61 58/62 62/61 Fargo >25 (45 E) 19 23 >1.3(2.3E) >1.1 1.2 Sacramento 31 6 13 5.2 2.4 2.2 Spokane >16 (40E) 11 53 >1.5(3.6E) >0.3 4.9 SLC 31 Atlanta >14 (20E) 11 22 >1.3 Chicago >22 (30E) 28 36 >0.8 1.3 NYC 28 24 30 1.2 0.9 1.3 Seattle >20 26 <1.3 Portland 22 25 1.2 Helena >24 36 <1.5 Cincinnati 33 Network 35E 21 31 1.7E 1.2E 1.5 Avg. Hanford 80E 34 60 2.5E 1.3E 1.8 E = Estimated (data available for only part of year). Table 4. Sr-89 Deposition per cm rain (nCi/m2 per cm*) 1958 1961 1962 Site Precip Sr-89 Precip Sr-89 Precip Sr-89 New York 85 1.3 28 2.4 78 2.0 Pittsburgh 77 1.3 25 1.6 63 2.1 Chicago 60 1.3 54 >1 42 2.0 Vermilion, SD 33 2.5 14 5.7 57 2.2 Salt Lake City 18 2.9 12 5.4 20 3.7 Medford, OR ND 24 0.9 50 1.9 Richmond, CA 18 2.1 17 2.0 51 2.0 Seattle 43 2.5 20 2.5 59 2.5 *Totals for months with fallout. Precipitation in cm.
Appendix C Table 5. Monthly Precipitation (cm) Adams, Benton, Month Franklin Counties Walla Walla Stevens County County Seattle 1952 Nov-52 0.8 1.1 1.8 4.2 1954 Mar-54 2.0 2.8 2.6 5.4 Apr-54 0.8 3.4 2.3 6.9 May-54 1.0 1.7 3.5 4.5 Jun-54 1.1 3.0 3.3 4.6 Ju1-54 3.0 3.3 5.0 10 Total 8 14 17 31 1956 May-56 2.1 6.3 2.7 1.7 Jun-56 2.3 2.4 3.3 7.1 Ju1-56 0.7 0.3 2.0 0.2 Aug-56 0.9 3.8 3.3 2.4 Sep-56 0.4 0.3 0.4 5.6 Oct-56 2.6 5.4 4.9 10.4 Nov-56 0.6 1.7 0.8 4.1 Dec-56 1.5 4.9 2.5 6.8 Total 11 25 20 38 1957 Sep-57 0.4 4.0 2.0 4.7 Oct-57 1.3 4.0 4.0 9.2 Nov-57 2.0 5.3 7.0 12 Total 4 13 13 26 1958 Feb-58 4.8 5.0 9.0 14.3 Mar-58 2.0 4.3 3.2 6.6 Apr-58 2.8 9.1 7.1 3.7 May-58 1.7 5.5 1.6 2.3 Jun-58 1.2 2.5 3.5 2.1 Ju1-58 0.3 0.0 3.7 0 Aug-58 0.2 0.0 0.6 1.1 Sep-58 0.3 1.6 2.0 3.7 Oct-58 0.6 1.3 2.5 7.9 193
194 Table 5. con't. Review of the HTDS Draft Final Report Adams, Benton, Year Month Franklin Walla Walla Stevens Counties County County Seattle Nov-58 2.8 5.5 9.6 15.9 Total 17 35 43 58 1961 Sep-61 0.5 0.4 0.8 1.6 Oct-61 0.7 3.4 3.8 7.2 Nov-61 2.0 4.6 4.7 11.2 Dec-6 1 2.5 6.2 10.0 14.2 Total 6 15 19 34 1962 May-62 4.5 10.5 5.7 2.7 Jun-62 0.4 0.7 2.7 1.5 Ju1-62 0.0 0.0 0.1 4.0 Aug-62 1.1 1.1 2.0 5.1 Sep-62 1.1 5.2 3.2 8.7 Oct-62 3.2 8.5 5.9 1 8.1 Nov-62 2.2 5.9 7.6 9.7 Dec-62 2.2 6.9 5.2 4.9 1963 Jan-63 1.3 2.3 0.6 4.5 Total 16 41 33 59 Table 6. Ratio of Gummed-Film Gamma Dose Estimates Site 1954/58 1956/58 Boise, ID 0.3 0.5 Billings, MT 0.3 0.7 Salt Lake City 0.4 0.5 Grand Junction, CO 0.5 0.6 Seattle,WA 0.3 0.4 Medford, OR 0.1 0.4 San Francisco, CA 0.2 0.4 Yield ratio 0.7 0 4 Yield from surface shots: 100% in 1954, 75% in 1956, 67% in 1958.
Appendix C Table 7. Estimated Doses by Age-Group and County 195 Benton, Adams, Franklin I-131 Milk Infant t Child Teent Adult Deposition nCi-d/L mSv mSv mSv mSv ncilm2 G 1954 20 13 3 1.5 0.52 0.20 L 1956 20 13 3 1.5 0.52 0.20 O 1957 11 6 1 0.7 0.24 0.09 B 1958 50 30 6 3.3 1.20 0.45 A 1961 18 12 2 1.3 0.48 0.18 L *1962 36 (63) 22 4 2.4 0.88 0.33 TOTAL 155 96 1.5 N 1952 115 81 15 8.3 3.1 1.2 T 1953 53 29 6 3.4 1.2 0.5 S 1955 40 29 6 3.6 1.3 0.5 1957 76 83 16 8.7 3.2 1.2 TOTAL 284 222 3.3 (Franklin) Walla Walla I-131 Milk Infant t Childt Teent Adult Deposition nCi-d/L mSv mSv mSv mSv ncilm2 G 1954 36 24 5 2.9 1.0 0.38 L 1956 36 24 5 2.9 1.0 0.38 O 1957 30 18 4 2.2 0.72 0.29 B 1958 90 53 12 6.4 2.1 0.84 A 1961 33 22 5 2.6 0.88 0.35 L *1962 124 (190) 75 17 9.0 3.0 1.2 TOTAL 350 216 3.4 N 1952 175 95 18 11 3.8 1.4 T 1953 80 46 10 5.5 2.0 0.8 S 1955 60 36 9 4.9 1.8 0.7 1957 800 540 94 51 19 7.1 TOTAL 1120 717 10
196 Table 7. Estimated Doses (con 't.) Review of the HTDS Draft Final Report Stevens I-131 Milk Infant t Childt Teent Adult Deposition nCi-d/L mSv mSv mSv mSv ncilm2 G 1954 60 45 7 4.9 1.8 0.58 L 1956 60 45 7 4.9 1.8 0.58 O 1957 30 20 3 2.2 0.8 0.26 B 1958 150 90 14 9.9 3.6 1.2 A 1961 45 30 5 3.3 1.2 0.39 L *1962 106(145) 66 11 7.2 2.6 0.86 TOTAL 450 296 3.8 N 1952 150 110 18 10 4.1 1.3 T 1953 250 150 29 16 6.4 2.1 S 1955 50 47 6 5 2.1 0.5 1957 90 100 15 9 4.0 1.3 TOTAL 550 460 5.2 1951, 1958 NTS, 1952 global fallout doses negligible. *deposition through November (deposition through Jan 1963 in parenthesis). t Totals not applicable because individuals will change age-category. Infant: 1-5 months Child: 1-4 yr. Teen: 10-14 yr.
Appendix C REFERENCES 197 iEstimated Exposures and Thyroid Doses Received by the American People from Iodine-131 in Fallout Following Nevada Atmospheric Nuclear Bomb Tests. National Cancer Institute, 1997. 2Reports.of the United Nations Scientific Committee on the Effects of Atomic Radiation. UNSCEAR, 1982, 1993. 3Hanford Environmental Monitoring Program Annual Report for 1961, HW- 71999; Hanford Environmental Monitoring Program Annual Report for 1962, HW-76526. See also J.K. Soldat, The Relationship between I-131 Concentrations in Various Environmental Samples, Health Physics 9, 1167, 1963. Anderson, B.V., Hanford Environmental Monitoring Annual Report-1958, HW-61676. Radiological Heals Data. U.S. Public Health Service. Monthly Reports for 1958, 1961, 1962. 6Final Tabulation of Monthly Sr-90 Fallout Data: 1954-1976. USERDA Report HASL-329, 1977. 7USAEC Health and Safety Laboratory Quarterly Fallout Reports for 1958, 1959, 1961, 1962. ~Beck, H.L., Heifer, I.K., Bouville, A, Dreicer, M. Estimates of Fallout in the Continental U.S. from Nevada Weapons Testing Based on Gummed-film Monitoring Data, Health Physics 59~5), 565-576, 1990. 9Harley, J.H., N.A. Hallden and S.Y. Ong. Summary of Gummed-film Results Through December 1959. U.S.A.E.C Report HASL-93, Sept. 1960.