The massive production and use of silver nanoparticles (Ag NPs) have led to their increasing release into the environment. Even though the antimicrobial and cytotoxic effects of native nanoparticles have been well studied, the environmental impacts of transformation products such as silver sulfide nanoparticles (Ag2S NPs) have not been elucidated. In the present study, we assessed the toxicity of Ag2S NPs and silver nitrate (AgNO3), as a source of Ag, to the earthworm Eisenia andrei using a nominal concentration of 5 mg Ag kg-1 soil. We used the OECD guidelines to assess effects on weight loss and mortality for 14 days. After exposure, we also extracted the immune effector cells (coelomocytes) and conducted a battery of biomarker tests. To ensure the quality of the toxicological results, the structural changes of NPs during the experiment and the uptake of silver by the earthworms were monitored. During the experiment, mortality effects were not detected, but a weight loss was observed in the earthworms exposed to Ag2S NPs. Altough Ag2S NPs were engulfed by E. andrei cells, neither phenoloxidase activity nor lipid peroxidation differed from the untreated control group. Cells from earthworms treated with Ag2S NPs exerted very broad value range of nitric oxide (NO) generation, suggesting an imbalance in the NO metabolism. Overall, this study suggests minimal risks associated with Ag2S NPs exposure to earthworms. However, further studies are needed to assure no immunotoxicological or chronic effects on a wider range of terrestrial organisms.
- MeSH
- dusičnan stříbrný toxicita MeSH
- hmotnostní úbytek MeSH
- kovové nanočástice * chemie toxicita MeSH
- látky znečišťující půdu * toxicita MeSH
- Oligochaeta * MeSH
- půda chemie MeSH
- sloučeniny stříbra MeSH
- stříbro metabolismus toxicita MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVES: The aim of this study was to establish and evaluate the mortality rate, hatching rate and observe the presence of sublethal changes in zebrafish embryos after exposure to silver ions and nanoparticles. METHODS: Tests were conducted on newly fertilized zebrafish embryos, according to the modified OECD guideline 236, using a semistatic method and 96 hour incubation time. Silver nitrate and two different silver nanoparticles, stabilized with 0.01% solution of maltose and gelatine in the first case, and stabilized with polyvinylpyrrolidone, in the latter, were tested. RESULTS: Significant differences in toxicity of tested substances were recorded. The value of 96hLC50 for silver nitrate was 58.44 μg/L. The value of 96hLC50, calculated for silver nanoparticles stabilized with 0.01% solution of maltose and gelatine, was nearly 100 times higher, 4.31 mg/L. The value 96hLC50 for silver nanoparticles stabilized with polyvinylpyrrolidone exceeded 100mg/L, occurrence of sublethal effects caused by silver nanoparticles stabilized with polyvinylpyrrolidone was insignificant in most of the exposition groups, but only in this substance caused decreased hatching rate. CONCLUSION: Properties of different silver nanoparticles play an important role in levels of their toxicity and predominant mechanisms of action. In general, silver nanoparticles are less toxic for Danio rerio embryos than silver ions.
- MeSH
- dánio pruhované MeSH
- dusičnan stříbrný toxicita MeSH
- embryo nesavčí účinky léků MeSH
- LD50 MeSH
- maltosa MeSH
- nanočástice * MeSH
- povidon MeSH
- stříbro toxicita MeSH
- želatina MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
One hundred clinical isolates of Pseudomonas aeruginosa were checked for their sensitivity towards silver nitrate. Majority of the isolates were resistant at 20 mg/L and the resistance decreased with increasing concentration of silver nitrate, only 5% of the organisms showed resistance above 70 mg/L. These silver-resistant isolates were further checked for their resistance towards mercury and cadmium at 20 mg/L of concentration and the level of resistance was found to be 33 and 40%, respectively. A correlation between silver ion resistance and concurrent mercury and cadmium ion resistance was observed, suggesting a possible linkage between resistance towards various metal ions.
- MeSH
- dusičnan stříbrný metabolismus toxicita MeSH
- krysa rodu rattus MeSH
- Check Tag
- krysa rodu rattus MeSH
