Icelandic Radiation Safety Authority, Raudararstigur 10, IS-150 Reykjavik, Iceland.
Environ Monit Assess. 2012 Dec;184(12):7221-34. doi: 10.1007/s10661-011-2498-4. Epub 2012 Jan 21.
The aim of this study was to provide improved information on the long-term transfer of global nuclear weapons (137)Cs fallout to cow's milk in Iceland many years after deposition. The spatial variation in deposition was confirmed to be explained by precipitation. Soil samples showed a significant difference in (137)Cs deposition density between the main agricultural areas, with the South having the highest values, then the West and North and the lowest in the Northeast. There was no significant difference between the effective half-lives in (137)Cs activity concentrations in milk and milk powder from the main dairies in Iceland based on data for milk from 1990 to 2007 and for milk powder from 1986 to 2007. There was, however, a significant difference between the effective half-lives obtained for these two regions, 13.5 years for the Northern and 10.5 years for the Southern regions. These half-lives for global fallout are longer than those previously reported for similar time periods in other Arctic areas. The transfer of (137)Cs to cow's milk was quantified for different agricultural regions using aggregated transfer coefficients (T (ag)) for the period of peak global fallout soil inventory in 1965-1967. The values ranged from 2.8 × 10(-3) to 10.6 × 10(-3) m(2) kg(-1). By 2001-2004, the T (ag) values had only declined, in the main agricultural areas, to 0.6 × 10(-3)-1.0 × 10(-3) m(2) kg(-1). Long-term transfer rates to milk many years after deposition were high in Iceland compared with most other reported data. The transfer is potentially relevant for some of the contaminated areas around the Fukushima Nuclear Power Plant after the accident in March 2011 since limited information is available on uptake from Andosols and associated effective half-lives.
本研究旨在提供更多信息，说明在冰岛沉积多年后，全球核武器（137）Cs 沉降物向牛奶中的长期转移情况。证实了沉积的空间变化可以用降水来解释。土壤样本显示，主要农业区之间（137）Cs 沉积密度存在显著差异，南部最高，其次是西部和北部，东北部最低。根据 1990 年至 2007 年牛奶数据和 1986 年至 2007 年奶粉数据，冰岛主要奶牛场的牛奶和奶粉中（137）Cs 活度浓度的有效半衰期没有显著差异。然而，这两个地区的有效半衰期存在显著差异，北部为 13.5 年，南部为 10.5 年。这些全球沉降物的半衰期比以前报道的其他北极地区类似时期的半衰期要长。利用 1965-1967 年全球沉降物高峰期土壤清单的综合转移系数（T（ag）），对不同农业区向牛奶中（137）Cs 的转移进行了量化。这些值的范围从 2.8×10（-3）到 10.6×10（-3）m2kg（-1）。到 2001-2004 年，在主要农业区，T（ag）值仅下降到 0.6×10（-3）-1.0×10（-3）m2kg（-1）。与大多数其他报道的数据相比，沉积多年后牛奶中的长期转移率在冰岛很高。在 2011 年 3 月福岛核事故后，对福岛核电站周围一些受污染地区的吸收情况和相关有效半衰期的信息有限，因此这种转移情况可能具有相关性。
