LAUSR

This study investigated natural gamma emitting radionuclides 40K and 226Ra in rice consumed in Taiwan. Thirty rice samples, collected from local markets, included 24 local rice and 6 imported rice samples. Radionuclide activities were 24.05 ± 10.21 and 0.62 ± 0.61 Bq/kg for 40Kand 226Ra for all rice samples. The activity of each radionuclide was insignificantly different for local and imported samples (p = 0.33 and 0.52 for 40K and 226Ra, respectively). The annual effective doses from rice consumption were estimated to be 6.80 ± 2.89 and 7.86 ± 7.81 μSv/y for 40K and 226Ra, respectively, and the sum ingestion dose of 226Ra and 40K was 14.66 ± 8.57 μSv/y. These values were one order of magnitude less than the 290 μSv/y world average of the ingestion exposure from natural sources. The results suggest that rice consumption in Taiwan is radiologically safe for the investigated radionuclides.