The effect of radionuclide and heavy metal contamination of the Yenisei River on cytogenetics of aquatic plantElodea canadensis

Abstract

The study was done to determine concentrations of radionuclides and heavy metals and to evaluate the frequency of chromosomal aberrations in samples of Elodea canadensis, a submerged plant, collected in different parts of the Yenisei River. Samples were collected in the area subjected to radioactive impact of the Mining-and-Chemical Combine (MCC) at Zheleznogorsk and in the control areas, upstream of the MCC. The investigations showed that Elodea biomass in the area affected by MCC operation contained a long inventory of artificial radionuclides typical of the MCC discharges. Upstream of the MCC, in the control sampling areas, the sediments and the Elodea biomass contained only one artificial radionuclide-137 Cs. Thus, the exposure doses to Elodea shoots and roots upstream of the MCC are small (not more than 8 Gy/d) and the main contribution to them is made by natural radionuclides. At the MCC discharge site (the village of Atamanovo) and downstream of it, the total dose rate increases almost an order of magnitude, reaching its maximal values-72 Gy/d for Elodea shoots and 58 Gy/d for roots. Cytogenetic investigations of Elodea roots showed that at the MCC discharge site (the village of Atamanovo) and downstream of it the occurrence of chromosomal aberrations in ana-telophase and metaphase cells of Elodea was considerably higher than in the control area. It is highly probable that this simultaneous dramatic increase in the total exposure rate and the occurrence of chromosomal aberrations in Elodea is associated with the radiation factor. It is suggested that Elodea is affected not only by the radiation factor but also by the chemical factor-toxicity of heavy metals.

Types of cytogenetic abnormalities in apical root meristem of Elodea сanadensis from Yenisei River areas with different types of anthropogenic pollution

“…Водные виды растений сравнительно недавно стали при-меняться в качестве биоиндикаторов техногенного загрязнения, и цитоге-нетические работы с их использованием немногочисленны [13,16]. К числу массовых видов макрофитов, вегетирующих в районе реки Енисей, как в зоне техногенного загрязнения, так и на фоновых участках, относится Elodea canadensis Michx.…”

“…В результате ряда исследований в 2003-2006 гг. [10,16] и в 2011-2012 гг. [26] были подробно изучены ци-тогенетические характеристики элодеи канадской.…”

Chemical Fractionation of Radionuclides and Stable Elements in Aquatic Plants of the Yenisei River

“…While, however, mechanisms of accumulation and distribution of stable isotopes of heavy metals in aquatic plants have been thoroughly discussed in the literature, there are very few studies addressing the corresponding aspects of behavior of radionuclides. Laboratory experiments showed that artificial radionuclides are not uniformly distributed among different components of plant biomass. − Localization of radionuclides in the biomass of macrophytes determines further migration of radionuclides in the aquatic ecosystem, doses to specific cellular constituents and the subsequent radiotoxic effect …”

“…4À9 Localization of radionuclides in the biomass of macrophytes determines further migration of radionuclides in the aquatic ecosystem, doses to specific cellular constituents and the subsequent radiotoxic effect. 10 In most previous studies, aquatic plants were subjected to sequential extraction procedures to reveal mechanisms of accumulation of heavy metals. 11,12 There is, however, no generally accepted sequential extraction scheme for aquatic plants, similar to the Tessier procedure for soils and sediments.…”

Transfer of americium-241 from food and water to organs and tissues of the crucian carp

“…The sources of 241 Am in aquatic ecosystems are discharges from nuclear fuel reprocessing plants and decay of 241 Pu. 241 Am is detected in sediments and aquatic weeds of the Yenisei River [1,2] subjected to radioactive contamination from the Mining-and-Chemical Combine (ROSATOM) (Zheleznogorsk, 60 km downstream of the city of Krasnoyarsk). 241 Am, along with plutonium, dominates long term radiotoxicity.…”