Regulatory Mechanisms in Biosystems (Jul 2017)
Radiomonitoring of plant products and soils of Polissia during the long-term period after the disaster at the Chornobyl Nuclear Power Plant
Abstract
The article highlights the consequences of the Chernobyl disaster. Northern Polissia has been and still remains the most polluted area. Full scale and limited economic activity is carried out on part of the contaminated territories. The zone of radioactive contamination includes half of the territory of this region, one third of the agricultural land and almost the same amount of the arable land. 9 districts, 734 towns and villages are located within the zone of radioactive contamination. In the long-term period after the disaster the situation in the contaminated areas has improved and become predictable due to natural processes of recovery and implementation of countermeasures based on results of monitoring. However, until today regions of Ukrainian Polissia continue to produce agricultural products which do not meet the requirements of government regulations concerning the content of radionuclides in food and appear to present a threat to consumers. To assess the accumulation of 137Cs in plant products, we investigated the activity of these radionuclides in potatoes, vegetables, root crops and grains, and calculated the ratios of its transition from the ground to the products, which helped evaluate the intensity and amount of accumulation of radionuclides during the completion of the half-life period of 137Cs and evaluate the radiological situation in the northern regions of Polissia. The density of soil contamination with 137Cs and its specific activity in plant products grown on private plots were studied in three different districts of Zhytomyr region: Narodychi, Korosten and Ovruch. Analysis of the density of soil pollution with the 137Cs isotopes in the northern part of Zhytomyr region in the post-disaster period shows that even 30 years after the tragedy, significant areas of arable land under certain conditions remain potentially dangerous on account of contaminated plant products. The specific activity of 137Cs in plant products grown on private plots was studied in residential places where soil contamination was detected. In particular, the list of studied crops included: potato tubers, white cabbage, fresh tomatoes, table beets, carrots, onions, beans, oat grains, corn grains. The most critical were populated areas located in zone II – village Vystupovychi of Ovruch district, village Loznytsia and village Khrystynivka of Narodychi district. In these settlements an excess of DR-2006 in plant products was noted despite the fact that an excess over the maximum permissible level of density of soil pollution was not observed. In decreasing order by the amount of CT 137Cs, we ranked crops as follows: beans > table beets > carrots > potato tubers > corn grains ˃ oats grains > white cabbage > onions > fresh tomatoes. For the population living on radioactively contaminated territories, plant products grown on private plots have been and still remain the main source of 137Cs radionuclides entering the body.
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