Table 6 Risk Coefficients? for Marshall Islanders, 5~Year Latent Period Excess Group Years ; Thyroid Total at Risk Cancers Person-Rad Risk Coefficient Age 1954 Number <10 10-18 85 32 2.2 2.7 120, 000 21,000 17.2 22.7 1.1x1076 5.8x107° 237 6.8 200,000 14.9 2.3x1076 >18 Total 120 1.9 56,000 11.2 3.0x1076 4thyroid cancers per person~rad-years at risk, based on thyroid dose from internal plus external sources. Table 7 Estimated Risk Coefficient? for Internal and External Exposure 10-Year Latent Period 5-Year Latent Period External Internal External Internal Risk Risk Risk Risk © Coefficient Coefficient Coeffictent Coefficient 85 32 120 3.3x107° 3.3x107 1.0x1076 1.4x1078€6) 8.0xL07° 6.1x107° 2,5%1078 2.5x1076 1.3x107° 1.0x107° 6.31076 3.3x107° 237 2.1x107° 4.7x107° 1.9x1076 2.9x107° Group Age 1954 <10 10-18 >18 Total Number *“Thyroid cancers per person-rad-years at risk. b A value of 1.3x107° results when 4.9x107° is used for the external risk ‘coefficient. 26