Grzegorz Olszewski

Uranium (234U, 235U and 238U) contamination of the environment surrounding phosphogypsum waste heap in Wiślinka (northern Poland)

The aim of this work was to determine the uranium concentration ((234)U, (235)U and (238)U) and values of the activity ratio (234)U/(238)U in soil samples collected near phosphogypsum waste heap in Wiślinka (northern Poland). On the basis of the studies it was found that the values of the (234)U/(238)U activity ratio in the analyzed soils collected in the vicinity of phosphogypsum dump in Wiślinka are in most cases close to one and indicate the phosphogypsum origin of the analyzed nuclides. The obtained results of uranium concentrations are however much lower than in previous years before closing of the phosphogypsum stockpile. After this process and covering the phosphogypsum stockpile in Wiślinka with sewage sludge, phosphogypsum particles are successfully immobilized. In the light of the results the use of phosphate fertilizers seems to be a major problem. Prolonged and heavy rains can cause leaching accumulated uranium isotopes in the phosphogypsum stockpile, which will be washed into the Martwa Wisła and on the fields in the immediate vicinity of this storage.

Polonium (210Po), uranium (234U, 238U) isotopes and trace metals in mosses from Sobieszewo Island, northern Poland

The activity of polonium 210Po and uranium 234U, 238U radionuclides, as well as trace metals in mosses, collected from Sobieszewo Island area (northern Poland), were determined using the alpha spectrometry, AAS (atomic absorption spectrometry) and OES-ICP (atomic emission spectrometry with inductively coupled plasma). The concentrations of mercury (directly from the solid sample) were determined by the cold vapor technique of CV AAS. The obtained results revealed that the concentrations of 210Po, 234U, and 238U in the two analyzed kinds of mosses: schrebers big red stem moss (Pleurozium schreberi) and broom moss (Dicranum scoparium) were similar. The higher polonium concentrations were found in broom moss (Dicranum scoparium), but uranium concentrations were relatively low for both species of analyzed mosses. Among the analyzed trace metals the highest concentration in mosses was recorded for iron, while the lowest for nickel, cadmium and mercury. The obtained studies showed that the sources of polonium and uranium isotopes, as well as trace metals in analyzed mosses are air city contaminations transported from Gdańsk and from existing in the vicinity the phosphogypsum waste heap in Wiślinka (near Gdańsk).

Is ecological food also radioecological? – 210Po and 210Pb studies

Presented are results of a study on accumulation of naturally occurring 210Po and 210Pb in ecological and conventional farming food products in Poland: fruits, vegetables and cereals. The main idea behind this research was to determine the activity concentrations of 210Po and 210Pb in ecological and commercial food as well as calculate and compare the effective dose (radiation) connected to different origin of analyzed food products consumption. The studies showed the majority of all compared food samples contained similar 210Po and 210Pb activities and statistically, the consumption of organic and commercial food would give similar annual effective dose.

A study on possible use of Urtica dioica (common nettle) plants as uranium (234U, 238U) contamination bioindicator near phosphogypsum stockpile

The aim of this study was to determine uranium concentrations in common nettle (Urtica dioica) plants and corresponding soils samples which were collected from the area of phosphogypsum stockpile in Wiślinka (northern Poland). The uranium concentrations in roots depended on its concentrations in soils. Calculated BCF and TF values showed that soils characteristics and air deposition affect uranium absorption and that different uranium species have different affinities to U. dioica plants. The values of 234U/238U activity ratio indicate natural origin of these radioisotopes in analyzed plants. Uranium concentration in plants roots is negatively weakly correlated with distance from phosphogypsum stockpile.