Retention level of Cs-137 and K-40 in some users of an Egyptian nuclear research center

Body burden activities of Cs-137 and K-40 of about 120 humans, of composite sex, were measured using Inshas whole body counter facilities. The contained body burden activity in such distribution is found to be 3.5–10 Bq l−1 for Cs-137 and 3.39×10−3 kg l−1 as well as 3.69×10−3 kg l−1 for K-40 respectively for females and males. It was found, that the amount of Cs kg l−1 K increases significantly with increase of either the body volumes and/or the total body potassium. It seemed reasonably to conjecture that, from the results of this study, the retention time of Cs-137 in body is closely connected to the amount of K-40. The discrimination factor related to the body burden content of Cs-137 to K-40 is also experimentally predicted. Moreover, the burden activities of Cs-137 and K-40 over a period of two years are scanned monthly. The results show a slight continuous increase in body burden activity of both elements. The net daily intakes of Cs-137 and K-40 are calculated using a formula developed from ICRP. The calculated results for K-40 show a variation ranging from 30 to 40 Bq per day for females and from 45 to 55 B per day for males. While for Cs-137 show a slight variation ranged from 5.2 to 6.8 Bq per day for a composite sex. The authors emphasise the importance of the periodic measurement of human population since both the consumed food chain and the environmental enclosure contained both radio elements. Accumulation of the daily ingested activity of Cs-137 and K-40, and of food eaten, showed that the predicted body burden retained activity is relatively higher by a range of 5–25% for Cs-137 and 3–15% for K-40 when compared with that detected by the whole body counter over the 24-month scanning course.