Bioaccumulation of silver nanoparticles in rainbow trout (Oncorhynchus mykiss): Influence of concentration and salinity
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- 作者：Hamid Salari Joo ; Mohammad Reza Kalbassi ; Il Je Yu ; Ji Hyun Lee ; Seyed Ali Johari
- 关键词：Rainbow trout ; Silver nanoparticles ; Salinity ; Bioaccumulation ; UV&ndash ; vis spectroscopy
- 刊名：Aquatic Toxicology
- 出版年：2013
- 出版时间：15 September, 2013
- 年：2013
- 卷：140-141
- 期：Complete
- 页码：398-406
- 全文大小：1708 K
文摘
With the increasing use of silver nanoparticles (Ag-NPs), their entrance into aquatic ecosystems is inevitable. Thus, the present study simulated the potential fate, toxicity, and bioaccumulation of Ag-NPs released into aquatic systems with different salinities. The Ag-NPs were characterized using inductively coupled plasma-atomic emission spectroscopy (ICP-AES), dynamic light scattering (DLS), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDX), and UV-vis spectroscopy. Juvenile rainbow trout were exposed to Ag-NPs in three different salinity concentrations, including low (0.4 ppt), moderate (6 ¡À 0.3 ppt), and high (12 ¡À 0.2 ppt) salinity, for 14 days in static renewal systems. The nominal Ag-NP concentrations in the low salinity were 0.032, 0.1, 0.32, and 1 ppm, while the Ag-NP concentrations in the moderate and high salinity were 3.2, 10, 32, and 100 ppm. UV-vis spectroscopy was used during 48 h (re-dosing time) to evaluate the stability and possible changes in size of the Ag-NPs in the water. The results revealed that the ¦Ëmax of the Ag-NPs remained stable (415-420 nm) at all concentrations in the low salinity with a reduction of absorbance between 380 and 550 nm. In contrast, the ¦Ëmax quickly shifted to a longer wavelength and reduced absorbance in the moderate and higher salinity. The bioaccumulation of Ag in the studied tissues was concentration-dependent in all the salinities based on the following order: liver > kidneys ¡Ö gills > white muscles. All the tissue silver levels were significantly higher in the high salinity than in the moderate salinity. In addition, all the fish exposed to Ag-NPs in the low, moderate, and high salinity showed a concentration-dependent increase in their hepatosomatic index (HSI). In conclusion, most Ag-NPs that enter into freshwater ecosystems (low ionic strength) remain suspended, representing a potentially negative threat to the biota in an ionic or nanoscale form. However, in a higher salinity, nanoparticles agglomerate and precipitate on the surface of the sediment.