IAEA-Environment Laboratories, Monte Carlo, 98000, Monaco.
Centro Nacional de Aceleradores, Universidad de Sevilla, Isla de la Cartuja, 41092, Sevilla, Spain.
J Environ Radioact. 2020 Apr;214-215:106157. doi: 10.1016/j.jenvrad.2020.106157. Epub 2020 Jan 11.
In February 2004, anthropogenic radionuclides (Cs, U, Pu and Pu), transported from the Sahara Desert, were observed in the Monaco air, and later in water and sediment samples collected at the DYFAMED site in the northwest (NW) Mediterranean Sea. While U and Cs in Saharan dust particles showed a high solubility in seawater, Pu isotopes were particle reactive in the water column and in the sediment. The impact of the Saharan deposition was found at 0-1.0 cm of the sediment core for U and Cs, and between 1.0 and 1.5 cm for Pu isotopes. The excess of U was observed more in the water column than in the sediment, whereas the Pu total inventories were comparable in the water column and the sediment. This single-day particle event represented 72% of annual atmospheric deposition in Monaco. At the DYFAMED site, it accounted for 10% (Cs) and 15% (Pu) activities of sinking particles during the period of the highest mass flux collected at the 200 and 1000 m water depths, and for a significant proportion of the total annual atmospheric input to the NW Mediterranean Sea (28-37% for Cs and 34-45% for Pu). Contributions to the total Cs and Pu sediment inventories were estimated to be 14% and 8%, respectively. The Saharan dust deposition phenomenon (atmospheric input, water column and sediment) offered a unique case to study origin and accumulation rates of radionuclides in the NW Mediterranean Sea.
2004 年 2 月，在摩纳哥空气中观测到了源自撒哈拉沙漠的人为放射性核素（Cs、U、Pu 和 Pu），随后在西北（NW）地中海的 DYFAMED 站点采集的水和沉积物样本中也发现了这些物质。虽然撒哈拉尘埃颗粒中的 U 和 Cs 在海水中具有高溶解度，但 Pu 同位素在水柱和沉积物中具有颗粒反应性。撒哈拉沉积物的影响在沉积物芯的 0-1.0 cm 处被发现，对于 Pu 同位素则在 1.0-1.5 cm 处被发现。水中 U 的过剩量大于沉积物中的 U，而 Pu 的总库存量在水柱和沉积物中相当。这种单日颗粒事件代表了摩纳哥大气年沉积量的 72%。在 DYFAMED 站点，在 200 和 1000 m 水深处采集的最大质量通量期间，沉降颗粒中 Cs 和 Pu 的活动量分别占 10%（Cs）和 15%（Pu），并且占西北地中海总大气输入量的很大一部分（Cs 为 28-37%，Pu 为 34-45%）。对 Cs 和 Pu 沉积物总库存量的贡献分别估计为 14%和 8%。撒哈拉尘埃沉降现象（大气输入、水柱和沉积物）为研究西北地中海放射性核素的来源和积累率提供了一个独特的案例。
