Evaluation of the ecotoxicity of model nanoparticles

Abstract

Since society at large became aware of the use of nanomaterials in ever growing quantities in consumer products and their presence in the environment, critical interest in the impact of this emerging technology has grown. The main concern is whether the unknown risks of engineered nanoparticles (NPs), in particular their impact on health and environment, outweighs their established benefits for society. Therefore, a key issue in this field is to evaluate their potential toxicity. In this context we evaluated the effects on plants and microorganisms of model nanoparticles, in particular of a stable metal (Au, 10nm mean diameter), a well-known bactericide (Ag, 2 nm mean diameter) and the broadly used Fe(3)O(4) (7 nm mean diameter). The toxicity of these nanoparticles was assayed using standard toxicity tests. Specifically, germination (cucumber and lettuce), bioluminescent (Photobacterium phosphoreum) and anaerobic toxicity tests were performed. Germination tests were conducted at a NP dose of 62, 100 and 116 microg mL(-1) for Au, Ag, and Fe(3)O(4), respectively. The bioluminscent testing (P. phosphoreum) was conducted at a dose of 28, 45 and 52 microg mL(-1) for Au, Ag, and Fe(3)O(4), respectively. Finally, anaerobic tests were conducted at a NP dose of 10, 16 and 18 microg mL(-1) for Au, Ag, and Fe(3)O(4), respectively. In all cases low or zero toxicity was observed. However, some perturbation of the normal functions with respect to controls in germinating tests was observed, suggesting the necessity for further research in this field. At the same time, the effect of NP-solvents was sometimes more significant than that of the NPs themselves, a point that is of special interest for future nanotoxicological studies.

Ecotoxicity test methods for engineered nanomaterials: Practical experiences and recommendations from the bench

“…Such information may be vital, however, because, for plants at least, a need exists for alternative dose metrics. Particle number or surface area appears to be more relevant than mass-based toxicity to plants for ENMs [79]. Because of these current technical difficulties, ecotoxicity testing on soil organisms can be supported by a strategy that uses liquid media instead of soil, such as aquatic nematode tests or hydroponic plant tests.…”

Use of ecotoxicity test and ecoscores to improve the management of polluted soils: case of a secondary lead smelter plant

“…First used to assess acute ecotoxicity of metals in aquatic media [40] and normalized since 2007 [41], solid-phase Microtox ® test is now currently used to evaluate the toxicity of contaminated soils or sediments [4,42,43]. The Microtox test measures the decrease in light emitted by the bioluminescent bacteria Vibrio fischeri after 5, 15 and 30 min of exposure [43].…”

“…The Microtox test measures the decrease in light emitted by the bioluminescent bacteria Vibrio fischeri after 5, 15 and 30 min of exposure [43]. In view of evaluating toxicity of collected soils, the Microtox 81.9% Basic Test with the instrument MICROTOX M 500 purchased from R-Biopharm (France) was used.…”

Review of Applications and Environmental Fate of Gold Nanoparticles

“…However, Barrena et al's study indicate that such restrictions does not bring out the complete toxicity of nanomaterials in the environment [32]. Their bioluminescent test to evaluate the harmful effects of solvent and suspension of GNP discharged into the surface waters did not present any toxic effects.…”