The accident at the Fukushima nuclear power plant in 2011 caused the release of large amounts of tellurium (Te) isotopes, with radio-cesium (Cs) and radio-iodine (I), into the environment. The total amounts of
127mTe and
129mTe released from the nuclear power plant were estimated as 1.1 × 10
15 and 3.3 × 10
15 Bq, respectively. At the location where the deposition of
129mTe was relatively large, the ratio of the radioactivity of
129mTe to that of
137Cs reportedly reached 1.49 on June 14, 2011. Since
127mTe has a relatively long half-life, it possibly contributed to the internal radiation dose at the early stage after the accident. In this paper, the ratio of the committed effective dose of
127mTe to that of
137Cs after the oral ingestion of rice was estimated by using various reported parameters. The relevant parameters are: 1) the deposition ratios of
127mTe,
129mTe, and
134Cs to
137Cs; 2) the deposition ratio of
127mTe to
129mTe; 3) the transfer factors of Te and Cs; and 4) the effective dose coefficients for
127mTe,
129mTe,
134Cs, and
137Cs. The ratios of the committed effective dose of
127mTe to that of
137Cs were calculated for adults after a single ingestion at the time of the rice harvest. The ratio was 0.45 where the
129mTe/
137Cs in the soil was higher and 0.05 where the level of
129mTe/
137Cs was average. The ratio of the committed effective dose from
129mTe and
127mTe to that from
137Cs for one year reached 0.55 and 9.03 at the location where the level of
129mTe/
137Cs in the soil was higher. These data could indicate that radioactive Te should not be disregarded in reconstructing the internal radiation dose from food for one year after the accident.
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