Product Description
This digital document is a journal article from Journal of Environmental Radioactivity, published by Elsevier in 2005. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.Description: Lichens are widely used to assess the atmospheric pollution by heavy metals and radionuclides. However, few studies are available in publications on using lichens to qualitatively assess the atmospheric pollution levels. The paper presents research results applying epiphytic lichens as bio-monitors of quantitative atmospheric contamination with uranium. The observations were conducted during 2.5 years in the natural environment. Two experimental sites were used: one in the vicinity of a uranium contamination source, the other one - at a sufficient distance away to represent the background conditions. Air and lichens were sampled at both sites monthly. Epiphytic lichens Hypogimnia physodes were used as bio-indicators. Lichen samples were taken from various trees at about 1.5m from the ground. Air was sampled with filters at sampling stations. The uranium content in lichen and air samples as well as isotopic mass ratios ^2^3^5U/^2^3^8U were measured by mass-spectrometer technique after uranium pre-extraction. Measured content of uranium were 1.45mgkg^-^1 in lichen at 2.09E-04@mgm^-^3 in air and 0.106mgkg^-^1 in lichen at 1.13E-05@mgm^-^3 in air. The relationship of the uranium content in atmosphere and that in lichens was determined, C"A"I"R=exp(1.1xC"L"I"C"H"E"N-12). The possibility of separate identification of natural and man-made uranium in lichens was demonstrated in principle.