Determination of transfer factors of ²¹⁰Po (²¹⁰Pb) from soil to some short-life vegetable crops

In this study, the transfer factors of ²¹⁰Po were determined in the samples of the hydroponic loose-leaf lettuces (Lactuca sativa var. longifolia) collected in Thu Duc City in Ho Chi Minh City. The loose-leaf lettuce is an integral ingredient of the common diet in Viet Nam. The ²¹⁰Po activity concentrations in these samples were measured by the alpha spectroscopy manufactured by Canberra Company, Inc. The activity concentrations of ²¹⁰Po of the dried lettuce samples varied in the range of 2,3 ± 0,3 Bq.kg-1 and 11,6 ± 1,2 Bq.kg-1 ( the mean value was 5,8 ± 0,7 Bq.kg-1) and ranged from 11,4 ± 1,2 Bq.kg-1 to 32,7 ± 5,2 Bq.kg-1 (the mean value was 21,5 ± 3,0 Bq kg-1) in the soil samples, respectively. The mean concentrations of transfer factor from soil to plant of ²¹⁰Po was found to be 0,27 ± 0,05. The dose coefficient of ²¹⁰Po by intake is 0,031 ± 0,020 (mSv.y-1) in the fresh loose-leaf lettuce and in order to keep the recommended dose for adult, a recommended intake of fresh hydroponic loose-leaf lettuce was proposed to be 10 kg per year. (author)