University Science Instrumentation Centre, Mangalore University, Mangalagangothri, 574199 Mangalore, India.
J Environ Radioact. 2013 Oct;124:101-12. doi: 10.1016/j.jenvrad.2013.03.008. Epub 2013 May 15.
Detailed studies were carried out to establish site-specific soil to grass transfer factors (Fv) and grass to cow milk transfer coefficients (Fm) for radioactive cesium ((137)Cs) and stable cesium (Cs) for Kaiga region, where a nuclear power station has been in operation for more than 10 years. The study included adopted cows, cows of local farmers, and cows from the dairy farm. A grass field was developed specifically for the study and 2 local breed cows were adopted and allowed to graze in this grass field. The soil and grass samples were collected regularly from this field and analyzed for the concentrations of (137)Cs and stable Cs to evaluate the soil to grass Fv values. The milk samples from the adopted cows were analyzed for the (137)Cs and stable Cs concentrations to evaluate Fm values. For comparison, studies were also carried out in dominant grazing areas in different villages around the nuclear power plant and the cows of local farmers which graze in these areas were identified and milk samples were collected and analyzed regularly. The geometric mean values of Fv were found to be 1.1 × 10(-1) and 1.8 × 10(-1) for (137)Cs and stable Cs, respectively. The Fm of (137)Cs had geometric mean values of 1.9 × 10(-2) d L(-1) and 4.6 × 10(-2) d L(-1), respectively, for adopted Cows 1 and 2; 1.7 × 10(-2) d L(-1) for the cows of local farmers, and 4.0 × 10(-3) d L(-1) for the dairy farm cows. The geometric mean values of Fm for stable Cs were similar to those of (137)Cs. The Fm value for the dairy farm cows was an order of magnitude lower than those for local breed cows. The Fm values observed for the local breed cows were also an order of magnitude higher when compared to the many values reported in the literature and in the IAEA publication. Possible reasons for this higher Fm values were identified. The correlation between Fv and Fm values for (137)Cs and stable Cs and their dependence on the potassium content ((40)K and stable K) in the soil and grass were also studied. In order to estimate the ingestion dose accurate data of the dietary habits of the population was necessary and this data was collected through a well planned demographic survey. The internal doses to a child due to the ingestion of (137)Cs along with the milk of the local cows and from the dairy farm were found to be 0.29 μSv y(-1) and 0.04 μSv y(-1),while that to an adult were 0.39 μSv y(-1) and 0.05 μSv y(-1), respectively.
详细的研究旨在建立特定地点的土壤到草转移因子（Fv）和草到奶牛奶转移系数（Fm），用于研究卡加地区放射性铯（137Cs）和稳定铯（Cs）的情况，该地区的一座核电站已经运行了 10 多年。该研究包括采用的奶牛、当地农民的奶牛和来自奶牛场的奶牛。专门开发了一个草地区域供研究使用，并采用了 2 头当地品种的奶牛在这片草地上放牧。定期从这片草地采集土壤和草样，并分析其 137Cs 和稳定 Cs 的浓度，以评估土壤到草 Fv 值。从采用的奶牛采集奶样并定期分析 137Cs 和稳定 Cs 的浓度，以评估 Fm 值。为了进行比较，还在核电站周围不同村庄的主要放牧区进行了研究，确定了在这些地区放牧的当地农民的奶牛，并定期采集和分析奶样。发现 137Cs 和稳定 Cs 的 Fv 几何平均值分别为 1.1×10-1和 1.8×10-1。采用的奶牛 1 和 2 的 137Cs 的 Fm 的几何平均值分别为 1.9×10-2 d L-1和 4.6×10-2 d L-1；当地农民的奶牛为 1.7×10-2 d L-1；奶牛场的奶牛为 4.0×10-3 d L-1。稳定 Cs 的 Fm 几何平均值与 137Cs 的相似。奶牛场奶牛的 Fm 值比当地品种奶牛低一个数量级。与文献和国际原子能机构出版物中报告的许多值相比，当地品种奶牛的 Fm 值也高一个数量级。确定了导致这种更高 Fm 值的可能原因。还研究了 137Cs 和稳定 Cs 的 Fv 和 Fm 值之间的相关性及其对土壤和草中钾含量（40K 和稳定 K）的依赖性。为了准确估计摄入量剂量，需要对人口的饮食习惯进行详细的调查，这项数据是通过精心策划的人口普查收集的。当地奶牛和奶牛场奶牛的牛奶中摄入 137Cs 导致的儿童体内剂量分别为 0.29μSv y-1和 0.04μSv y-1，而成年人的体内剂量分别为 0.39μSv y-1和 0.05μSv y-1。
