Chege M W, Hashim N O, Merenga A S, Tschiersch J
Physics Department, Kenyatta University, Mombasa Campus, PO Box 16778, Mombasa, Kenya
Physics Department, Kenyatta University, PO Box 43844, Nairobi, Kenya.
Radiat Prot Dosimetry. 2015 Nov;167(1-3):276-8. doi: 10.1093/rpd/ncv261. Epub 2015 May 5.
Specific concentrations of (226)Ra, (232)Th and (40)K were measured in cassava tubers, cassava leaves and groundwater obtained from the high background radiation area of Mrima hill and used in the evaluation of the ingested dose. Cassava tubers, cassava leaves and groundwater registered average (226)Ra concentrations of 60 ± 5, 141 ± 11 and 4.3 ± 0.3 Bq kg(-1), respectively. (232)Th was not detected in cassava leaves although it was present in cassava tubers as well as in groundwater in average concentrations of 35.3±61.5 and 2.0±0.1 Bq kg(-1), respectively. (40)K was present in all samples in average concentrations of 842±539 Bq kg(-1) in cassava tubers, 1708 ± 552 Bq kg(-1) in cassava leaves and 91.4 Bq kg(-1) in groundwater. The total annual effective dose due to ingestion was found to be 7.9 mSv y(-1) of which 2.4 mSv y(-1) was due to cassava tubers, 3.8 mSv y(-1) due to cassava leaves and 1.7 mSv y(-1) due to water.
对取自姆里马山高本底辐射区的木薯块根、木薯叶和地下水进行了镭 - 226、钍 - 232和钾 - 40的特定浓度测量，并用于评估摄入剂量。木薯块根、木薯叶和地下水的镭 - 226平均浓度分别为60±5、141±11和4.3±0.3贝克勒尔每千克。木薯叶中未检测到钍 - 232，但其存在于木薯块根和地下水中，平均浓度分别为35.3±61.5和2.0±0.1贝克勒尔每千克。所有样品中均存在钾 - 40，木薯块根中的平均浓度为842±539贝克勒尔每千克，木薯叶中的平均浓度为1708±552贝克勒尔每千克，地下水中的平均浓度为91.4贝克勒尔每千克。因摄入导致的年总有效剂量为7.9毫希沃特每年，其中2.4毫希沃特每年归因于木薯块根，3.8毫希沃特每年归因于木薯叶，1.7毫希沃特每年归因于水。
