Abstract：
Commercial animal feed in Texas was characterized by determining natural gamma emitters including 40K,137Cs, and Uranium (235U and 238U) and Thorium (232Th) series to obtain basic radioactivity values. The measured activity concentration of natural radionuclides in animal feed was low enough for safe consumption by animal and largely depended on the type of animal feed.40K was the predominant radionuclide showing the highest activity concentration in animal feed. The radioactivity concentration of 214 Bi and 214Pb in 238U decay series was 1.39 and 1.33 Bq/kg in corn, respectively, lower than in other animal feed types. On the other hand, the vitamin/mineral mix samples showed higher concentrations of 214 Bi (9.04 Bq/kg) and 214Pb (10.19 Bq/kg). Beef cattle feed, poultry feed, and vitamin/mineral mix exhibited higher activity concentration of 228Ac and 212Pb in 232Th decay series. Gamma radionuclides appeared to be highly and significantly correlated within each decay series. 235U was present at low levels in all feed samples while the anthropogenic radionuclide of 137Cs was not detected irrespective of the type of animal feed. This study highlights an importance of establishing a current baseline of radioactivity concentration in animal feed in Texas in which the largest animal feed consumption in the US exists.
摘要：
德克萨斯州的商业动物饲料的特征是确定包括40K在内的天然γ发射体，137Cs,和铀(235U和238U)和钍(232Th)系列获得基本放射性值。动物饲料中测得的天然放射性核素的活性浓度很低，足以供动物安全食用，并且在很大程度上取决于动物饲料的类型。40K是动物饲料中活性浓度最高的主要放射性核素。238U衰变系列中214Bi和214Pb在玉米中的放射性浓度为1.39和1.33Bq/kg,分别,低于其他动物饲料类型。另一方面,维生素/矿物质混合物样品显示浓度较高的214Bi(9.04Bq/kg)和214Pb(10.19Bq/kg).肉牛饲料,家禽饲料,维生素/矿物质混合物在232Th衰变系列中表现出更高的228Ac和212Pb活性浓度。在每个衰变系列中，伽玛放射性核素似乎高度相关且显着相关。235U在所有饲料样品中均以低水平存在，而与动物饲料的类型无关，均未检测到人为放射性核素137Cs。这项研究强调了在德克萨斯州建立动物饲料中放射性浓度的当前基线的重要性，德克萨斯州是美国最大的动物饲料消费。
