Table 14. Annual effective dose from natural
background in the United States.2
Source of radiation
Effective dose
mSv (mrem)
Cosmic radiation
- 0.27 (27)
Cosmogenic radionuclides
Terrestrial radiation
Inhaled radionuclides (radon)
Radionuclides in the body
Total
a Data from NCRP (1987a).
Marshall Islands.
0.01 (1)
0.28 (28)
2 (200)
0.40 (40)
3 (300)
Thus, most of the natural
background in the Marshall Isiands is due to
external cosmic radiation and internal dose from
naturally occurring radionuclides in local foods.
The external dose from terrestrial radiation is
in local fresh and imported f
ingestion of these radionuclides, a
the quantities of different foods
annual effective dose as well) of[2.0 mSv y—!
(200 mrem y-!). Unlike the majority of dose from
man-made radionuclides, which is Herived from
137Cs associated with terrestrial fogds, 87% and
74% of 210Po and 219Pp, respectivelf, in the total
diet is derived from the local afd imported
aquatic foods, including seabirds] A detailed
report on the 210Po and 219Pb congpntrations in
Marshallese foods and the resultihg dose rate
calculations can be found in Ndshkin et. al
(1993).
-Radiation dose guidelines arq established
without the inclusion of natural fbackground
very low.
dose at Rongelap Island of
(26 mrem y-!) is 26% of the current
0.22 mSv y-? (22 mrem y-!) (USAEC 1973;
recommended by the NCRP and
1987b; ICRP, 1990).
The effective dose rate from cosmic
radiation in the Marshall Islands is about
Gudiksen et al., 1976). An additional 0.18 mSv
Table 15. Adopted guidelines for the general public, natural background doses in the Unitgd States and
Marshail Islands, and estimated doses from man-madesources at Rongelap Island.
Population average effective dose rate mSv y~! (Inrem y-)
Adopted annual guideline
1 (100)
Rongelap Island: man-made sources
0.26 (26)
U.S. natural background
- 3 (300)
Marshall Island natural background
Cosmic
0.22 (22)
Terrestrial
210Po9 (diet)
40K (diet)
210Pb (diet)
2.4 (240)
0.01 (1)
0.01 (1)
1.8 (180)
0.18 (18)
0.20(20)
Rongelap Island: natural background plus
man-made sources
2.66 (266)
US. 30-y integral dose guideline
|
0.05 Sv> (5 rem>)
Rongelap: man-madesources (30-y integral dose)
0.0059 (0.59 rem)
a The source of these estimated doses are discussed in Noshkin et al. (1993).
b Whole-body equivalent dose.
32