Grażyna Bystrzejewska-Piotrowska

Nanoparticles: their potential toxicity, waste and environmental management.

This literature review discusses specific issues related to handling of waste containing nanomaterials. The aims are (1) to highlight problems related to uncontrolled release of nanoparticles to the environment through waste disposal, and (2) to introduce the topics of nanowaste and nanotoxicology to the waste management community. Many nanoparticles used by industry contain heavy metals, thus toxicity and bioaccumulation of heavy metals contained in nanoparticles may become important environmental issues. Although bioavailability of heavy metals contained in nanoparticles can be lower than those present in soluble form, the toxicity resulting from their intrinsic nature (e.g. their size, shape or density) may be significant. An approach to the treatment of nanowaste requires understanding of all its properties--not only chemical, but also physical and biological. Progress in nanowaste management also requires studies of the environmental impact of the new materials. The authors believe Amaras law is applicable to the impact of nanotechnologies, and society might overestimate the short-term effects of these technologies, while underestimating the long-term effects. It is necessary to have basic information from companies about the level and nature of nanomaterials produced or emitted and about the expectation of the life cycle time of nanoproducts as a basis to estimate the level of nanowaste in the future. Without knowing how companies plan to use and store recycled and nonrecycled nanomaterials, development of regulations is difficult. Tagging of nanoproducts is proposed as a means to facilitate separation and recovery of nanomaterials.

Transport of radiocesium in mycelium and its translocation to fruitbodies of a saprophytic macromycete

We present a new protocol to study fluxes of radionuclides and other xenobiotics in saprophytic fungi. This simple method has successfully been used to evaluate transport of radiocesium in hyphae of Pleurotus eryngii and its translocation to fruitbodies.

A study of mechanisms responsible for incorporation of cesium and radiocesium into fruitbodies of king oyster mushroom (Pleurotus eryngii).

Ex vitro cultures of Pleurotus eryngii were carried out under controlled conditions using sterile medium composed of barley seeds. The influence of alkali and alkaline earth element salts (CsCl, KCl, NaCl, RbCl, and CaCl(2)) and tetraethylammonium chloride on incorporation of cesium, potassium, sodium, rubidium and calcium, and their distribution within fruitbodies, was examined. The results show that incorporation of cesium into fruitbodies was not suppressed by Na(+) and Rb(+) or tetraethylammonium chloride. However, it was inhibited by Ca(2+) and stimulated by high concentrations of K(+). The inhibition of cesium incorporation by Ca(2+), lack of influence of tetraethylammonium chloride and stimulation by high K(+) concentrations suggest that there may exist two pathways of passive transport of cesium in mycelium: (i) uptake mediated by a non-specific potassium channel localised in plasmalemma (similar to voltage-insensitive cation channel, VICC) followed by diffusive transport inside hyphae and (ii) extracellular transport from the medium through inter-hyphal cavities into fruitbodies. The results highlight distinctiveness of mechanisms responsible for the uptake and incorporation of cesium in mushrooms and plants.

Accumulation and translocation of cesium-137 in onion plants (Allium cepa)

Abstract The distribution of 137 Cs and 40 K was characterized among the layers of the storage organ of edible onion. In the internal bulb layers, a significant correlation ( r =0.96) between cesium and potassium concentrations was found. On the other hand, the 137 Cs/ 40 K ratio in the dry senile leaves was significantly increased. Uptake of cesium by leaves and roots (from 0.3 mM CsCl in Tris–HCl pH 7 buffer) was investigated under controlled conditions. In the period of 48 h, intensive acropetal and basipetal transport took place. In another test, onion seedlings were incubated in 0.3 mM CsCl solution within 24 h. After transferring them to the un-contaminated soil, three groups of onion were grown for 4, 8 and 12 days. The decrease in 137 Cs content in the plants after 8 and 12 days was observed, particularly in the roots, whereas the leaf 137 Cs content was not changed. Onion accumulates cesium to a great extent. It was shown that Allium cepa takes up cesium from the fallout and is a 137 Cs-reservoir, from which it is being released to the unpolluted soil.

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

Abstract Water environments are noted as being some of the most exposed to the influence 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 fish Danio rerio. The influence of exposition time, concentration and the source of nanoparticles on the efficiency of AgNP accumulation were studied. It was found that AgNPs are efficiently accumulated by Chironomid larvae for the first 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 fish and certainly higher levels of Ag in the trophic chain. In comparison with water contamination, silver nanoparticles are more efficiently accumulated if fish 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

Pilot Study of Bioaccumulation and Distribution of Cesium, Potassium, Sodium and Calcium in King Oyster Mushroom (Pleurotus Eryngii) Grown Under Controlled Conditions

This pilot study presents preliminary results on interrelations between alkali and alkaline earth elements during their transfer to mycelium and fruitbodies of saprophytic fungi. The accumulation and distribution of four elements (cesium, potassium, sodium, and calcium) was evaluated in king oyster mushroom (Pleurotus eryngii) cultivated under controlled conditions. Elemental composition of caps, stipes, and the substrate was analyzed by atomic absorption/emission spectroscopy to evaluate discrimination, concentration, and transfer factors. The transfer factors determined for all the investigated elements were different and can be put in the following order: Cs > K > Na > Ca. There has been a higher accumulation of cesium in caps than in stipes. Distribution of cesium in fruitbodies depended on the presence of other ions in the substrate. The addition of Ca2+ limited the transport of cesium and potassium from stipes to caps. Sodium and calcium were mainly accumulated in the stipes. In a control experiment, without supplementation with K+, Na+, and Ca2+, ∼ 62% of the cesium present in the substrate was extracted by mycelium and transported to the fruitbodies. Possible applications of fruiting saprophytic fungi in bioremediation are discussed.

Tufted hairgrass (Deschampsia caespitosa) exhibits a lower photosynthetic plasticity than Antarctic hairgrass (D. antarctica).

The aim of our work was to assess photosynthetic plasticity of two hairgrass species with different ecological origins (a temperate zone species, Deschampsia caespitosa (L.) Beauv. and an Antarctic species, D. antarctica) and to consider how the anticipated climate change may affect vitality of these plants. Measurements of chlorophyll fluorescence showed that the photosystem II (PSII) quantum efficiency of D. caespitosa decreased during 4 d of incubation at 4 degrees C but it remained stable in D. antarctica. The fluorescence half-rise times were almost always lower in D. caespitosa than in D. antarctica, irrespective of the incubation temperature. These results indicate that the photosynthetic apparatus of D. caespitosa has poorer performance in these conditions. D. caespitosa reached the maximum photosynthesis rate at a higher temperature than D. antarctica although the values obtained at 8 degrees C were similar in both species. The photosynthetic water-use efficiency (photosynthesis-to-transpiration ratio, P/E) emerges as an important factor demonstrating presence of mechanisms which facilitate functioning of a plant in non-optimal conditions. Comparison of the P/E values, which were higher in D. antarctica than in D. caespitosa at low and medium temperatures, confirms a high degree of adjustability of the photosynthetic apparatus in D. antarctica and unveils the lack of such a feature in D. caespitosa.

Titanium Dioxide Nanoparticle Circulation in an Aquatic Ecosystem

Nanotechnology is a dynamically developing field of scientific and industrial interest across the entire world, and the commercialization of nanoparticles (NPs) is rapidly expanding. Incorporation of nanotechnologies into a range of manufactured goods results in increasing concern regarding the subsequent release of engineered NPs into the environment. One of the biggest threats of using NPs is the transfer and magnification of these particles in the trophic chain. The aim of the studies was the evaluation of the distribution of TiO2 NP contamination in the aquatic ecosystem under laboratory conditions. Bioaccumulation of TiO2 NPs by plants (Elodea canadensis) and fish (Danio rerio) in the source of contamination was investigated. The studies were focused on the consequences of short-term water contamination with TiO2 NPs and the secondary contamination of the components of the investigated model ecosystem (plants, sediments). It was found that in the fish and the plants exposed to NP contamination, the amount of Ti was higher than in the control, indicating an effective bioaccumulation of NPs or ions originating from NPs. It was clearly shown that the NPs present in the sediments are available to plants and fish. Additionally, the aquatic plants, an important trophic level in the food chain, can accumulate NPs and be a source of NPs for higher organisms. It was concluded that even an incidental contamination of water by NPs may result in long-term consequences induced by the release of NPs.