Radiological Measurement Laboratory / Biological Physics, Dpt. of Chemistry and Physics of Materials, Salzburg University, Austria.
Dpt. of Biosciences, Salzburg University, Austria.
J Environ Radioact. 2023 Apr;259-260:107102. doi: 10.1016/j.jenvrad.2022.107102. Epub 2023 Jan 17.
Alpine regions in the federal state of Salzburg (Austria) have been intensively contaminated by Chernobyl fallout, necessitating long-term monitoring programs. The sites predominately affected are those in areas with soil developed on silicate bedrock, as these soils tend to be acidic, favouring high transfer factors for Cs. In addition, nutrient deficiency, low mineral and high organic matter content, and tough climatic conditions are causing the slow migration of Cs in the soil, which are associated with long effective half-lives in the biosphere. As a quantitative measure for effective half-lives, milk has been collected at nine alpine seasonal stock farming sites since 1988; at four sites, the monitoring is still ongoing (2020). For the period between 1999 and 2020, the decrease of Cs can be reasonably fitted with one effective half-life describing the time-trend. The effective half-lives obtained by this procedure vary between 9.3 ± 0.9 years and 18.8 ± 3.4 years. The effective half-lives show a weak negative correlation with the half-value depth of Cs, defined as the depth of the upper soil layer containing half of the deposited fallout inventory. The majority of the inventory is bound in the rooting zone of 0-10 cm, which is reflected by the small half value depths in the range between 3.2 and 4.4 cm. The soils investigated are acidic with pH values between 3.78 and 4.88, showing a pronounced negative correlation with the effective half-lives of Cs in milk. The data indicate that in these soils rich in organic matter, which are also almost totally devoid of clay minerals and have a very low clay size fraction, pH may be the dominating factor influencing the effective half-lives of Cs plant uptake and the subsequent contamination of milk.
萨尔茨堡联邦州（奥地利）的高山地区受到切尔诺贝利沉降物的严重污染，需要进行长期的监测计划。受影响的主要是那些土壤发育在硅酸盐基岩上的地区，因为这些土壤往往呈酸性，有利于 Cs 的高转移系数。此外，养分缺乏、低矿物质和高有机质含量以及恶劣的气候条件导致 Cs 在土壤中的缓慢迁移，这与生物圈中长的有效半衰期有关。作为有效半衰期的定量测量，自 1988 年以来，在九个高山季节性畜牧场收集了牛奶；其中四个监测点仍在继续（2020 年）。在 1999 年至 2020 年期间，Cs 的减少可以用一个有效半衰期来合理拟合，描述时间趋势。通过该程序获得的有效半衰期在 9.3±0.9 年到 18.8±3.4 年之间变化。有效半衰期与 Cs 的半值深度呈弱负相关，半值深度定义为包含一半沉降物库存的上土壤层的深度。大部分库存都绑定在 0-10cm 的根系区，这反映在半值深度在 3.2 到 4.4cm 之间的小范围内。所研究的土壤呈酸性，pH 值在 3.78 到 4.88 之间，与牛奶中 Cs 的有效半衰期呈显著负相关。这些数据表明，在这些富含有机质的土壤中，几乎完全缺乏粘土矿物，且具有非常低的粘土地形部分，pH 值可能是影响 Cs 植物吸收和随后牛奶污染的有效半衰期的主要因素。
