Metals and radionuclides in mushrooms from selected areas in Slovenia

Polona Zakrajšek (2014) Metals and radionuclides in mushrooms from selected areas in Slovenia. Diploma thesis.

Preview

PDF Download (5Mb)

Abstract

Mushrooms in their fruiting bodies accumulate significant quantities of macro- and microelements, potential toxic elements (PSE) and radionuclides. Fungal vegetation represent an important nutritional intake of some essential minerals in relativity high concentrations, while at the same time fungi allow for transferring pollutants to higher trophic levels and may represent a serious risk to animal and humans health. The aim of the graduation thesis was to determine the content of certain minerals, PSE and radioactive isotopes in soil and selected mushroom species, collected from different areas in Slovenia. Mushrooms and soil samples were collected in 7 different locations: Dragomer, Hotič, Kolovrat, Janče, Jastrebnik, Lj.-Rožnik and Sitarjevec. Concentrations of elements and specific activity of radionuclides were determined by energy X-ray fluorescence spectroscopy (XRF) and High-Resolution Gamma-ray Spectrometry (HRGS). The results showed that concentrations of Fe, Mn, Zn and all nonessential elements were the highest in soil collected in Jastrebnik. Critical levels of Pb were exceeded in soil collected in Sitarjevec, at the vicinity of former Pn and Zn mine. In addition the highest Pb and Zn concentrations in mushrooms, were measured in this area. Concentrations of minerals and PSE in fruiting bodies of mushrooms are species-specific. Mushrooms (for example Boletus) in their fruiting bodies contain a great source of essential macro- and microelements, particularly selenium. We calculated the relative proportions of elements in 100 g mushrooms. With daily intake of 100 g fresh edible mushrooms Slovenian and world Dietary Reference Intakes (DRI) for selenium were exceeded. The largest concentration of selenium was in Albatrellus pes-caprae (Goat’s foot) specie. The results of HRGS analysis showed the presence of natural radionuclides 238U, 226Ra, 210Pb, 228Ra, 228Th in 40K and an artificial radionuclide 137Cs. Specific activity of the majority of natural radionuclides are the highest in soil by Jastrebnik. Concerns are raised due to high average specific activity of 137Cs. However it has to be emphasized, that the samples were primarily collected in forest ecosystem, where pollutants are known to accumulate in plant litter.

Actions (login required)