Desorption of 137Cs from Cetraria islandica (L.) Ach. lichen was performed by five consecutive desorptions with five identical solution volumes. Solutions of H2SO4, HNO3 and their mixtures, with pH 4.61, 5.15 and 5.75 were used for desorption. The desorbed amount of 137Cs (average value, all solutions used) from lichen, for a given pH value was 49.2% for pH 4.61; 47.0% for pH 5.15 and 47.6% for pH 5.75. The obtained values of the desorbed amount of 137Cs from lichen are in accordance with the data obtained in earlier work, when 46.2 % 137Cs was desorbed from lichen for pH 3.75, and 47.2% was desorbed for pH 2.87. A higher percentage of 59.8%, obtained for pH 2.00 indicates increased activity of H+ ions. The amount of desorbed 137Cs from lichen using solutions corresponding to acid rain cannot be lower than the stated values as they contain other substances besides the acid solutions used in this work

Izvod Desorpcija 137 Cs iz mahovine Homalothecium sericeum (Hedw.) Schim. vršena je korišćenjem pet uzastopnih desorpcija sa pet identičnih zapremina rastvora. Za desorpciju su korišćeni rastvori: H 2 SO 4 , HNO 3 i njihova smeša, H 2 SO 4 -HNO 3 , pH vrednosti 4,61; 5,15 i 5,75; kao i destilovana voda pH 6,50. Posle pet sukcesivnih desorpcija iz mahovina je od sorbovane kiseline desorbovano od 22,8% (rastvor H 2 SO 4 -HNO 3 pH 5,75) do 33,2% (rastvor H 2 SO 4 -HNO 3 pH 4,60) 137 Cs, a destilovanom vodom 31,3% 137 Cs. Prvom desorpcijom iz mahovine desorbuje se najviše 137 Cs, od 9,0 do 17,9%. Srednje vrednosti procenta ukupno desorbovanog 137 Cs iz mahovine su slične: za rastvor H 2 SO 4 28,8%; HNO 3 25,7% i H 2 SO 4 --HNO 3 28,6%, što ukazuje da NO 3 i SO 4 2nemaju uticaj na desorpciju Cs + . Korišćene pH vrednosti rastvora ne utiču značajno na desorpciju 137 Cs iz mahovine. Posle pet sukcesivnih desorpcija iz mahovine 137 Cs se ne desorbuje u značajnoj meri. U intervalu pH od 4,61 do 6,50 desorpcione supstance su H 2 O i H + , a manji uticaj imaju SO 4 2i NO 3 -. Postoje dva mesta sorpcije, odnosno dve vrste sorpcije, pri čemu je jedna dominantna. Ključne reči: desorpcija 137 Cs, Homalothecium sericeum (Hedw.) Schim. mahovina, kisele kiše.

Penny bun (Boletus edulis) and chanterelle (Cantharellus cibarius) are fungi used for human consumption in several forms: fresh, thermally treated, or conserved (salted, marinated, pasteurized, dried). Random samples were collected on the territory of the Republic of Serbia in the period 1999-2018 intended for export to the EU. The presence of 137Cs was noted in each individual fungi sample. The higher activity level of 137Cs in fresh penny bun samples was noted in 2001 (25.9 Bqkg?1), while in fresh chanterelle samples it was noted in 2000 (18.6 Bqkg?1). Marinating the fungi reduced activity levels of 137Cs in relation to the fresh fungi activity, for penny bun from 1.6 to 12.6 times for a year, while for chanterelle from 0.8 to 14.7 times for a year. Drying the fungi increases activity levels of 137Cs: for penny bun from 0.04 to 0.29 times for a year, while for chanterelle from 0.03 to 1.94 times for a year. The values of annual effective radiation doses were much lower than the recommended values for the population (1 mSv).

1 In sti tute for the Ap pli ca tion of Nu clear En ergy, Uni ver sity of Bel grade, Belgrade, Ser bia 2 Fac ulty of Phys i cal Chem is try, Uni ver sity of Bel grade, Bel grade, Ser bia Sci en tific pa per https://doi.org/10.2298/NTRP190520034CEx trac tion of 137 Cs from: Hypnum cupressiforme and Isothecium myurum mosses was in ves tigated us ing the fol low ing so lu tions: H 2 SO 4 , HNO 3 , and a mix ture of H 2 SO 4 and HNO 3 at three pH val ues (4.61, 5.15, and 5.75) and dis tilled wa ter (pH = 6.50). 19.1-34.7 and 18.4-30.5, and us ing dis tilled wa ter 29.1 and 26.9. Sorp tion of 137 Cs was per formed at no less than two sorp tion points in moss tis sue. In the in ves ti gated pH re gion no sig nif i cant in flu ence of H 2 SO 4 or HNO 3 on 137 Cs ex trac tion was noted in re la tion to wa ter ex trac tion, i. e. ex trac tion with acid rain with pH > 4.6. Af ter five suc ces sive desorption pro cesses last ing 24 hours the fol low ing amounts of 137 Cs [%] were ex tracted from mosses: us ing acid so lu tions

fitness in anthropogenic induced stressful conditions. Further studies of synergistic effect of genetic and environmental stress are needed, as well as studies of its outcome in natural populations.