Technical Summary
TS.5. Estimation of the Thyroid Doses from 131I

 


For each test and each county, average thyroid doses from 131I have been estimated for 13 age categories, including the fetus, with adults subdivided by gender:

  • fetus (0-10 wks; 11-20 wks; 21-30 wks; 31-40 wks),
  • infant (0-2 mos; 3-5 mos; 6-8 mos; 9-11 mos),
  • child (1-4 yrs; 5-9 yrs; 10-14 yrs; 15-19 yrs)
  • adult male,
  • adult female.

For each of those age categories, average thyroid doses have been estimated for:

  • The population that consumed average volumes of cows' milk containing average concentrations of 131I.
  • A specified "high-exposure" group, with a high consumption of cows' milk with higher-than-average concentrations of 131I.
  • The group drinking milk obtained from backyard cows.
  • A specified "low-exposure" group (non-milk drinkers).

For each test, these estimates of average thyroid dose, as well as the uncertainties that are attached to those estimates, are presented in the Sub-annex devoted to the test under consideration in the form of a Table for each age category.

In addition, the per capita thyroid doses from 131I have been estimated for each test and each county. For each test, these estimates of per capita thyroid dose, as well as the uncertainties that are attached to those estimates, are presented in the Annex devoted to the test under consideration in the form of a Table. Figure TS.4 presents the estimated per capita thyroid doses for each county of the contiguous United States summed over all tests. In general, the highest per capita thyroid doses, in the range of 5 to 16 rads, were obtained in counties of western states located east and north of the NTS, such as Utah, Idaho, Montana, Colorado, and Missouri. In many counties on or near the west coast, the border with Mexico, and parts of Texas and Florida, the per capita thyroid doses were lowest, in the range of less than 0.1 to 0.5 rad. The average per capita thyroid dose from all tests is estimated to have been about 2 rads.

back to table of contents