Bioaccumulation of polonium (²¹⁰Po) and uranium (²³⁴U, ²³⁸U) in plants around phosphogypsum waste heap in Wiślinka (northern Poland)

Abstract

Phosphogypsum waste heap / Northern Poland / Polonium 210 Po / Uranium 234 U, and 238 U / Concentration / Plants Summary. In the study the activities of polonium 210 Po and uranium 234 U, 238 U in plants, collected near phosphogypsum waste heap in Wiślinka (northern Poland), were determined by using the alpha spectrometry. The obtained results revealed that the concentrations of 210 Po, 234 U, and 238 U in the analyzed plants were differentiated. In the analyzed flora organisms the highest amounts of polonium and uranium were found in ruderal plant samples as well as willow samples (Salix viminalis) from protection zone of phosphogypsum waste heap. The concentrations of 210 Po, 234 U and 238 U in the analyzed plants were higher in roots than in green parts of plants. The higher concentrations of 210 Po and 238 U radionuclides were estimated for hydrophyte (common sedge Carex nigra Reichard), the favourite habitat of which is particularly wet meadow and for plants collected in the vicinity of phosphogypsum waste heap. The major source of polonium and uranium in analyzed plants is root system. The values of 234 U/ 238 U activity ratio in all analyzed plants are closed to one, what indicated that source of uranium in analyzed plants is phoosphogypsum. The highest uranium and polonium concentrations were characterized for plants, which are covered with tomentose.The comparability polonium and uranium contents were confirmed in edible plants, but higher accumulation was determined in ripe species than immature species of vegetables. The higher polonium and uranium concentrations were noticed in green parts of plant, the lower in roots. Polonium concentration in cultivated plants samples was not species diverse. Therefore, the significant source of polonium and uranium in analyzed plants is wet and dry atmospheric falls gathering the soil and air dust from phosphogypsum waste dump.The maximum 210 Po and 238 U radionuclides concentrations were found in green parts of red beet (Beta vulgaris esculenta), the minimum in garden radish (Raphanus radicula). That's interesting too, that both species have hypocotyls tubers, but tuber of red beet is large than garden radish. In our opinion these differences may be connected with turgidity because leaves and root of radish garden were withered.

The radiochemical contamination (210Po and238U) of zone around phosphogypsum waste heap in Wiślinka (northern Poland)

“…The higher activity of 210 Po, 234 U and 238 U in hygrophilous plants suggests that groundwater is a very important source of radionuclides to tissues and organs of these plants. [40,41] The rehabilitation plan of the analyzed phosphogypsum waste heap includes its irrigation, which means more soluble radionuclides may easily be available for uptake by plants. [35] The similar effect was recorded in southern Spain, where the uranium concentration in groundwater Downloaded by [Duke University Libraries] at 03:28 05 January 2015 around a fertilizer factory complex was significantly higher than those in other areas of the same aquifer.…”

“…The obtained differentiated results between polonium and uranium bioaccumulations in roots of chosen meadow plants can prove that more polonium and uranium radionuclides were accumulated in plants which have the storage root system, and less by the fibrous roots system [41,47] However, the placing of roots in water-logged area means that more soluble radionuclides may easily be available for uptake by plants. [18,44,46] The smaller 210 Po and 238 U concentrations were noticed in analyzed edible plants.…”

“…turgidity of plants (determined by the water saturation). [41] Also the some herbaceous perennial flowering plants have a very shortened stem, which forms the so-called 'bulb'. [53,54] Thanks to this structure the water from atmospheric precipitation can flow downwards to the underground part of plant.…”

The radiochemical contamination (210Po and238U) of zone around phosphogypsum waste heap in Wiślinka (northern Poland)

“…Despite having the same storage root system and the same tubers, plants accumulate varied amounts of radionuclides and this fact may be connected with e.g. turgidity of plants (determined by the water saturation) (Boryło and Skwarzec, 2011). Also the some herbaceous perennial flowering plants have a very shortened stem, which forms the so-called 'bulb' (Szafer et al, 1988).…”

“…Also the some herbaceous perennial flowering plants have a very shortened stem, which forms the so-called 'bulb' (Szafer et al, 1988). Thanks to this structure the water from atmospheric precipitation can flow downwards to the underground part of plant (Boryło and Skwarzec, 2011).…”