Wyniki wyszukiwania - BazTech

1

Silver nanoparticle accumulation by aquatic organisms – neutron activation as a tool for the environmental fate of nanoparticles tracing

Asztemborska M., Jakubiak M., Książyk M., Stęborowski R., Polkowska-Motrenko H., Bystrzejewska-Piotrowska G.

Nukleonika

|

2014

|

Vol. 59, No. 4

169--173

EN

Water environments are noted as being some of the most exposed to the infl uence of toxic nanoparticles (NPs). Therefore, there is a growing need for the investigation of the accumulation and toxicity of NPs to aquatic organisms. In our studies neutron activation followed by gamma spectrometry and liquid scintillation counting were used for studying the accumulation of silver nanoparticles (AgNPs) by freshwater larvae of Chironomus and fi sh Danio rerio. The infl uence of exposition time, concentration and the source of nanoparticles on the effi ciency of AgNP accumulation were studied. It was found that AgNPs are effi ciently accumulated by Chironomid larvae for the fi rst 30 hours of exposition; then, the amount of silver nanoparticles decreases. The silver content in larvae increases together with the NP concentration in water. Larvae which have accumulated AgNPs can be a source of nanoparticles for fi sh and certainly higher levels of Ag in the trophic chain. In comparison with water contamination, silver nanoparticles are more effi ciently accumulated if fi sh are fed with AgNP-contaminated food. Finally, it was concluded that the applied study strategy, including neutron activation of nanoparticles, is very useful technique for tracing the uptake and accumulation of NPs in organisms.

2

Estimation of the acute cesium toxicity by the microbial assay for risk assessment (MARA) test

Bronowska M., Stęborowski R., Bystrzejewska-Piotrowska G.

Nukleonika

|

2013

|

Vol. 58, No. 4

481--485

EN

The microbial assay for risk assessment (MARA) test was used for acute cesium toxicity evaluation in water solutions. The test contained 11 different microorganisms with a wide spectrum of sensitivity. The resistance of microorganisms to cesium was characterized as follows: microbial toxic concentration (MTC), half maximal inhibitory concentration (IC50), maximal inhibitory concentration (IC100). The sensitivity to cesium was characterized by the lowest observed effect level (LOEL). High levels of sensitivity in the range 3.1–6.3 mM were shown by the following microorganisms: Serratia rubidaea > Pseudomonas aurantiaca, Delftia acidovorans, Citrobacter freundii, Staphylococcus warneri. Lower levels of sensitivity (up to 16 mM) were noted for Comamonas testosteroni, Microbacterium species, Kurthia gibsonii, Pichia anomala, whereas that in the range 24–31 mM for Brevundimonas diminuta > Enterococcus casseliflavus. High resistance to Cs+ was found for E. casseliflavus (MTC 86.9 g/l) > the yeast – P. anomala (MTC 19.3 g/l) > K. gibsoni (MTC 17.4 g/l) > B. diminuta (MTC 13.4 g/l). The phenomenon of resistance of enterococcus and yeast strains was discussed.

3

Application of neutron activation for investigation of Fe3O4 nanoparticles accumulation by plants

Bystrzejewska-Piotrowska G., Asztemborska M, Stęborowski R., Polkowska-Motrenko H., Danko B., Ryniewicz J.

Nukleonika

|

2012

|

Vol. 57, No. 3

427-430

EN

As a result of the rapid development of nanotechnology and increasing application of nanoproducts in many areas of everyday life, there is a growing risk of production of nanowastes potentially dangerous for the environment. This makes it necessary to investigate the accumulation and toxicity of nanoparticles (NPs) at different trophic levels. In the studies neutron activation was applied for the investigation of iron (II,III) oxide nanoparticle (Fe3O4-NPs) accumulation by Lepidium sativum and Pisum sativum L. Plants were cultivated on growth medium contaminated with different concentrations (0.01-10 mmolźL-1) of Fe3O4-NPs. For the identification of the presence of Fe3O4-NPs in plant tissues gamma spectrometry following iron oxide (II,III) nanoparticles irradiation was applied. Both plant species were found to accumulate iron (II,III) oxide nanoparticles. The highest content of NPs was found in plant roots, reaching 40 g/kg for Pisum sativum L. More than 90% of accumulated NPs were found in roots. Accumulation of Fe3O4-NPs was found to depend on the concentration of nanostructures in the growth medium. The transfer factor for Lepidium sativum roots and shoots and Pisum sativum L. shoots decreased with increasing NP concentration in the medium; for Pisum sativum L. roots the tendency was reversed. Neutron activation of nanoparticles was shown to be a powerful tool for tracing the environmental fate of NPs and their uptake and accumulation in organisms.

4

Resistance of heather plants (Calluna vulgaris L.) to cesium toxicity

Bystrzejewska-Piotrowska G., Drożdż A., Stęborowski R.

Nukleonika

|

2005

|

Vol. 50, nr 1

31-35

EN

Experiments were carried out to determine uptake and distribution of 137Cs, and total isotopes of Cs and K in plants of heather (Calluna vulgaris) growing at two levels of CsCl: 0.03 and 0.3 mM. Levels of Cs and K were determined in soil and in parts of plants: roots, stem, leaves and flowers. Also calculated were: (i) transfer factor of Cs and K from soil to parts of plant and (ii) discrimination of K by Cs during the transport of Cs from roots to aboveground parts of plants, expressed as K/Cs discrimination factor. The results confirmed that heather plants are hyper-accumulators of cesium, because the accumulation of Cs in shoot was much greater than in roots. The K level in heather did not change at Cs concentrations as high as 8-fold Cs level in this plant. Heather plants seem to be relatively resistant to cesium toxicity at 0.3 mM of CsCl; the effect of exposure to CsCl at this concentration was exerted only on roots, without affecting leaves and flowers. These results supply new information on the interactions between Cs and K nutrition in plants; they also point to a possible role of heather in redistribution of the radiocesium pollution in the forest ecosystem.

5

Preliminary study of platinum accumulation in the fruitbodies of a model fungal species: king oyster mushroom (Pleurotus eryngii)

Urban P., Bazała M., Asztemborska M., Manjón J., Kowalska J., Bystrzejewska-Piotrowska G., Pianka D., Stęborowski R., Kuthan R. T.

Nukleonika

|

2005

|

Vol. 50,suppl.1

63-67

EN

A model species of saprophytic fungus, king oyster mushroom (Pleurotus eryngii), was cultivated on barley substrate supplied with [Pt(NH3)4](NO3)2, under well defined conditions. The samples of the collected fruiting bodies were digested and analyzed for total platinum content by means of ICP-MS. The results proved that platinum is not accumulated in the fruitbodies of Pleurotus eryngii for a wide range of Pt concentrations in the culture substrate (100 1000 ppb Pt in 50 ml of water solution added to ca. 450 g of hydrated barley seeds per container). Observable levels of Pt were only found in the fruitbodies obtained from the medium contaminated with 10000 ppb (10 ppm) platinum solution. This demonstrates significant difference in the effectiveness of platinum extraction in fungi and plants, which are capable to accumulate platinum even when supplied at lower concentration (<500 ppb). It also shows different physiological pathways of platinum and other elements which are easily accumulated in the fruitbodies of the same species.

6

Discrimination between 137Cs and 40K in the fruiting body of wild edible mushrooms

Bystrzejewska-Piotrowska G., Urban P., Stęborowski R.

Nukleonika

|

2003

|

Vol. 48, nr 3

155-157

EN

Samples of five species of wild edible mushrooms, growing in the vicinity of Warsaw, were analyzed in order to determine discrimination factors (DF) for 137Cs and 40K in their caps and stipes. The obtained DF values range from 0.80 to 2.87, and seem to be characteristic of each species. A brief discussion of the observed phenomenon is presented.