Migration Peculiarities of Technogenic Radionuclides in the Ecosystem of Lake Drūkšiai Under Anthropogenic Conditions in 1988–1998

Abstract

Activity concentrations of 137Cs, 60Co and 54Mn were determined in bottom sediments as well as in different species of hydrophytes and fish sampled at observation stations in Lake Drūkšiai and the Ignalina Nuclear Power Plant (INPP) wastewater canals. The radiogeochemical cartography of the distribution of radionuclide activity concentrations in hydrophytes growing in the littoral zone of the lake was produced. Sources of radionuclide inputs to the lake were identified. The impact of the Ignalina NPP wastewaters on bioaccumulation processes and migration of technogenic radionuclides in lake ecosystems was evaluated. It was established that in 1988–1998 the radioecological situation of Lake Drūkšiai was not stable. In hydrophytes, fish and bottom sediments of Lake Drūkšiai the lowest activity concentration values of radionuclides were observed in 1996–1998. Hydrophytes act as a primary barrier to radionuclide movement and reflect the one-season radioecological situation in a hydroecosystem most efficiently. However, bottom sediments, as a more conservative system, better reflect the long-lasting pollution with radionuclides.