Geology Department, William & Mary, Williamsburg, VA, USA.
Appalachian Laboratory, University of Maryland Center for Environmental Science, Frostburg, MD, USA.
Nat Commun. 2021 Mar 29;12(1):1937. doi: 10.1038/s41467-021-22081-8.
Cs is a long-lived (30-year radioactive half-life) fission product dispersed globally by mid-20th century atmospheric nuclear weapons testing. Here we show that vegetation thousands of kilometers from testing sites continues to cycle Cs because it mimics potassium, and consequently, bees magnify this radionuclide in honey. There were no atmospheric weapons tests in the eastern United States, but most honey here has detectable Cs at >0.03 Bq kg, and in the southeastern U.S., activities can be >500 times higher. By measuring honey, we show regional patterns in the biogeochemical cycling of Cs and conclude that plants and animals receive disproportionally high exposure to ionizing radiation from Cs in low potassium soils. In several cases, the presence of Cs more than doubled the ionizing radiation from gamma and x-rays in the honey, indicating that despite its radioactive half-life, the environmental legacy of regional Cs pollution can persist for more than six decades.
Cs 是一种长寿命（半衰期为 30 年）的裂变产物，在 20 世纪中叶的大气核武器试验中在全球范围内扩散。在这里，我们表明，远离测试地点数千公里的植被仍在继续循环 Cs，因为它模拟钾，因此蜜蜂在蜂蜜中放大这种放射性核素。美国东部没有进行大气武器试验，但这里的大多数蜂蜜中的 Cs 含量都可检测到 >0.03 Bq kg，在美国东南部，其活度可高达 500 倍以上。通过测量蜂蜜，我们展示了 Cs 生物地球化学循环的区域模式，并得出结论，植物和动物在低钾土壤中受到来自 Cs 的电离辐射的不成比例的高暴露。在某些情况下，Cs 的存在使蜂蜜中的伽马和 X 射线产生的电离辐射增加了一倍以上，这表明尽管其半衰期为 30 年，但区域 Cs 污染的环境遗留物可能会持续超过六十年。
