Institute of Oceanology, Polish Academy of Sciences, ul. Powstańców Warszawy 55, 81-712 Sopot, Poland.
J Environ Radioact. 2014 Jan;127:11-25. doi: 10.1016/j.jenvrad.2013.09.003. Epub 2013 Oct 8.
The Baltic Sea is susceptible to pollution by hazardous substances due to limited water exchange, shallowness, and the large catchment area. Radionuclides, particularly (137)Cs, are one of the most hazardous anthropogenic substances present in the Baltic environment. This study was conducted to present (137)Cs present contamination that should further be a subject of reliable monitoring when the new Nuclear Power Plant is put into operation in the northern Poland. The sea-wide, up to date distribution of (137)Cs activities and inventories in the Baltic Sea bottom sediments are presented. The (137)Cs activity concentrations were measured in 30 cm long sediment cores collected at 22 sampling stations. Sediment accumulation rates were quantified by (210)Pb geochronology to follow the history of (137)Cs accumulation. The (137)Cs inventories and fluxes were calculated. Most of the Baltic Sea sediments accumulated (137)Cs in the range from 750 to 2675 Bq m(-2). The Bothnian Bay is severely contaminated by (137)Cs with inventories up to 95,191 Bq m(-2). This region is moreover characterized by extremely large patchiness of (137)Cs inventories. The (137)Cs annual fluxes are highest at the two stations located at the Bothnian Bay (342 Bq m(-2) and 527 Bq m(-2)) due to large Chernobyl (137)Cs contamination of that region and high sediment accumulation rates. When these stations are excluded, the recent, annual mean value of (137)Cs load to the Baltic Sea deposits is 38 ± 22 Bq m(-2). The distribution of radio-caesium inventories over the Baltic Sea nowadays reflects the pattern of Chernobyl contamination. The radio-caesium deposited in surface sediments is not permanently buried, but may be resuspended and redeposited by currents, bioturbation or anthropogenic activities.
波罗的海由于水交换有限、水深较浅以及集水面积大，容易受到有害物质的污染。放射性核素，特别是 (137)Cs，是存在于波罗的海环境中的最危险的人为物质之一。本研究旨在介绍（137）Cs 的现有污染，当新的核电站在波兰北部投入运营时，应进一步对其进行可靠监测。本文介绍了波罗的海海底沉积物中（137）Cs 活动和储量的最新分布情况。在 22 个采样站采集了 30cm 长的沉积物岩芯，测量了（137）Cs 的活性浓度。通过（210）Pb 地球年代学来量化沉积物的堆积速率，以跟踪（137）Cs 积累的历史。计算了（137）Cs 的储量和通量。大多数波罗的海沉积物积累的（137）Cs 介于 750 至 2675 Bq m(-2) 之间。博特尼亚湾受到（137）Cs 的严重污染，储量高达 95191 Bq m(-2)。该地区的（137）Cs 储量分布极不均匀。两个位于博特尼亚湾的站点（342 Bq m(-2) 和 527 Bq m(-2)）的（137）Cs 年通量最高，这是由于该地区切尔诺贝利核事故（137）Cs 污染严重和高沉积物堆积速率所致。如果排除这两个站点，最近每年波罗的海沉积物中（137）Cs 的负荷为 38 ± 22 Bq m(-2)。如今，波罗的海中放射性铯储量的分布反映了切尔诺贝利污染的模式。沉积在表层沉积物中的放射性铯不会永久埋藏，而是可能被海流、生物搅动或人为活动重新悬浮和再沉积。
