Speaker
Ms
Karolina Szymanska
(Faculty of Chemistry, University of Gdansk)
Description
Most contamination studies have focused on alpha emitting plutonium isotopes so far. 241Pu is less important in terms of its radiotoxicity than the α-emitting plutonium radionuclides 238,239,240Pu but is quite significant because of its huge contribution to the whole plutonium fallout. Our previous experiments on air samples indicated extreme increase of 241Pu amount in atmospheric dust in April 1986. The available information about the bioaccumulation and distribution of 241Pu in the Baltic Sea ecosystem and Poland territory is still very limited. The main purpose of the present work was to complete the present knowledge and estimate the further levels of the Baltic Sea environment contamination.
The highest total 241Pu concentration in seawater was found in the Słupsk Bank (3.35±0.17 mBq∙dm-3) and this area had the highest concentration of 241Pu connected to suspended matter as well (1.94±0.12 mBq∙dm-3). High concentrations of 241Pu in the central part of the southern Baltic Sea can be a result of Baltic water circulation.
The 241Pu activity in phytoplankton sample from the Pomeranian Bay was 1.06±0.09 mBq∙g-1 dw. Within zooplankton samples the highest 241Pu activity was found in samples from the central part of the southern Baltic (2.66±0.16 mBq∙g-1 dw) and from the Gdańsk Deep (2.64±0.70 mBq∙g-1 dw). In zooplankton samples, similar situation to seawater samples was noticed – the highest concentrations of 241Pu were found in the central part of the southern Baltic Sea, and similarly to seawater it could be a result of Baltic water circulation.
Generally the data show significant differences in 241Pu concentrations among all the species examined. The highest values of 241Pu activities for whole organism were found in fish from Perciformes: benthic round goby (0.863±0.066 mBq∙g-1 ww) and pelagic perch (0.666±0.001 mBq∙g-1 ww). The lowest 241Pu activity was found in flounder (0.104±0.009 mBq∙g-1 ww). The plutonium was also non-uniformly distributed between the organs and tissues of the analyzed fish, especially pelagic herring and cod as well as benthic flounder.
In sediments, the highest amount of plutonium was found in the middle parts of all analyzed sediments and came from the global atmospheric fallout from nuclear tests in 1958-61. The distribution of 241Pu in analyzed sediments samples was not uniform and depended on the sediment geomorphology and depth as well as on its location.
The authors would like to thank the Ministry of Sciences and Higher Education for the financial support of this work under grant DS/530-8120-D384-14.
Primary author
Dr
Dagmara Struminska-Parulska
(Faculty of Chemistry, University of Gdansk)
Co-author
Ms
Karolina Szymanska
(Faculty of Chemistry, University of Gdansk)
