214 Health Physics Solid cancer and non-cancer disease mortality: 1950-1997. Radiat Res 160:381—407; 2003. Preston DL, Ron E, Tokuoka S, Funamoto S, Nishi N, Soda M, Mauchi K, Kodama K. Solid cancer incidence in atomic bomb survivors: 1958-1998. Radiat Res 168:164; 2007. Republic of the Marshall Islands. Republic of the Marshall Islands 1986 Statistical Abstract. Majuro: RMI Office of Planning and Statistics; 1987. (Reproduced in April 2003 by the Insular Areas Statistical Enhancement Program.) Republic of the Marshall Islands. Republic of the Marshall Islands 2001 RMIStatistical Abstract, 14" edition. Majuro: Economic Planning and Statistics Office; 2003. Ron E, Lubin JH, Shore RE, Mabuchi K, Modan B, Pottern LM, Schneider AB, Tucker MA, Boice JD Jr. Thyroid cancer after exposure to external radiation: a pooled analysis of seven studies. Radiat Res 141:259-—277; 1995. Simon SL, Bouville A, Land CE, Beck HL. Radiation doses and cancer risks in the Marshall Islands associated with exposure to August 2010, Volume 99, Number 2 radioactive fallout from Bikini and Enewetak nuclear weapons tests: summary. Health Phys 99:105—123; 2010a. Simon SL, Bouville A, Melo D, Beck HL, Weinstock RM. Acute and chronic intakes of fallout radionuclides by Marshallese from nuclear weapons testing at Bikini and Enewetak and related internal radiation doses. Health Phys 99:157—200; 2010b. Takahashi T, Trott KR, Fujimori K, Simon SL, Ohtomo H, Nakashima N, Takaya K, Kimura N, Konno T, SatomiS, Shoemaker M. An investigation into the prevalence of thyroid nodules and thyroid cancer on Kwajalein Atoll, Marshall Islands. Health Phys 73:199-—213; 1997. Takahashi T, Trott KR, Fujimori K, Nakashima N, Ohtomo H, Schoemaker MJ, Simon SL. Thyroid disease in the Marshall Islands, findings from 10 years of study. Sendai: Tohoku University Press; 2001. Young RW,Kerr GD. Reassessmentof the atomic bombradiation dosimetry for Hiroshima and Nagasaki: Dosimetry System 2002. Hiroshima: Radiation Effects Research Foundation; 2005. APPENDIX Minimum latent period of specific cancer types The models developed by the BEIR VII committee to estimate ERR and EARforsolid cancers and leukemia do not explicitly account for effects of the time delay between exposure to ionizing radiation and the earliest diagnosis of a radiation-induced cancer. Thus, for calculations of lifetime risk, the risk models need to be modified by a function that is assumed to represent the effect of a minimum latent period on reducing risk at early times since exposure. parameter S is set so that the latent period adjustment in equation (A1) attains values of approximately 0.01 and 0.99 at T = 4 and 11 y, respectively. Thus, risk is assumed to be very small (close to zero) at T < 4 y and to attain its full value at T > 11 y. This adjustment, to represent the effect of the minimum latent period on reducing ERR for mostsolid cancers, is given by the solid curve in Fig. Al. In their calculations of lifetime risk, the BEIR VII committee assumedthat the risk is equal to zero at times since exposure less than 5 y for solid cancers and less than 2 y for leukemia. No uncertainty was associated with this threshold function. In this study, to avoid an abruptincrease in risk from zero at times since exposure less than a minimum latency period to their maximum values at times when the minimum latent period has been exceeded, the effect of latency was represented by a sigmoid (‘S-shaped’) function Fratency(Z) = (Tp)? lt+e os (A 1 ) where is the time since exposurein years, pz 1s the value of T correspondingto the inflection point where Fyarency = 0.5, and S is a shape parameter that defines the steepness of the function as it increases from values near zero to values near the maximum of 1.0. For stomach, colon, and all solid cancers as a group, j2 is assumed to be 7.5 y and the shape 1.0 | 0.8— / / , / 3 | Z 08 | a4 - / Per cen | 0.2. 0.0 ! I a A e / L 0 4 ~ til es = ~~ 8th and 95t h | Time since exposure(y) : Fig. Al. Sigmoid (S-shaped) function representing the multiplicative adjustment factor (and its uncertainty) applied to the risk of stomach cancer, colon cancer and all solid . cancers (less thyroid : and non-melanoma) as a group, due to the effect of minimum : latency period at early times since exposure.