Abstract
The toxicity of manufactured nanoparticles varies greatly depending on the test species in consideration and estimates of toxicity may also be confounded by test media in which the organisms are cultured. For a more comprehensive toxicity evaluation, species at different trophic levels or with life strategies, tested in different media should be included. In this study, we examined the toxicity of tyrosine-coated silver nanonparticles (tyr-AgNP) to three Australian freshwater invertebrates: Hydra vulgaris, Daphnia carinata and Paratya australiensis. Tyr-AgNPs were synthesized, characterized and their behaviour was examined in different media used for acute toxicity tests. Additionally, the sensitivity of tested organisms to tyr-AgNPs was compared to ionic silver (Ag+). Based on the LC50 values of both tyr-AgNPs and Ag+ ions at different time points, D. carinata was found to be the most sensitive species followed by P. australiensis and H. vulgaris. NP stability studies revealed that tyr-AgNPs were least stable in hydra medium followed by daphnid and shrimp media. This study demonstrates that significant differences in NP toxicity to aquatic organisms exist and the test media and the life strategy of the species play a key role in these differences. Therefore, it is recommended that a multispecies approach is used in predictive risk assessment of NPs and to ensure protection of native species from possible toxic effects from NPs released into aquatic systems. Also recommended is to carefully investigate the fate and behaviour of NPs in different media in assessing NP toxicity and emphasize the need to use native species in developing relevant regulatory frameworks.
Highlights
Over the last 30 years, the number of products containing engineered nanomaterials increased across diverse fields mainly due to our growing capacity to synthesize and manipulate such materials (Nowack and Bucheli, 2007; Sun et al, 2017)
The objectives of the present study were to examine the toxicity of organic-coated AgNPs and Ag+ ions to three freshwater invertebrates at different trophic levels: the cnidarian Hydra vulgaris, the daphnid Daphnia carinata, and the freshwater shrimp Paratya australiensis and to compare species sensitivity and the influence of culture media on the toxicity of AgNPs
The toxicity of tyr-AgNPs and Ag+ ions to the three species was, respectively, in the order of daphnids > shrimps > hydra and shrimps > daphnids > hydra
Summary
Over the last 30 years, the number of products containing engineered nanomaterials increased across diverse fields mainly due to our growing capacity to synthesize and manipulate such materials (Nowack and Bucheli, 2007; Sun et al, 2017). AgNPs are used in a growing number of applications across a diverse range of commercial consumer products such as food storage containers, coating materials, liquid fabric softeners and detergents, fabrics and clothing, sporting goods, cosmetics, wound dressings, toothbrushes, and antimicrobial coatings (Alarcon et al, 2015; Wei et al, 2015; McGillicuddy et al, 2017). The presence of AgNPs has already been detected in the treated effluent at concentrations of 12 ng L−1 (Siripattanakul-Ratpukdi and Fürhacker, 2014) and 0.1 mg L−1 (Mitrano et al, 2012)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
