Ecotoxicity Assessment of Graphene Oxides Using Test Organisms from Three Hierarchical Trophic Levels to Evaluate...

Area of Science:

• Environmental Science
• Ecotoxicology
• Nanomaterial Safety

Background:

• Limited ecotoxicological data exists for graphene oxide nanomaterials (nGOs).
• Existing studies on nanomaterial toxicity yield contradictory results.
• Case-by-case evaluations using diverse methods and species are recommended.

Purpose of the Study:

• To evaluate the aquatic toxicity of two graphene oxide (GO) types (AF 96/97 and PM 995).
• To assess effects across various trophic levels including bacteria, protozoa, plants, and invertebrates.
• To determine potential environmental risk by estimating predicted no-effect environmental concentration (PNEC) values.

Main Methods:

• Tested two distinct GO types (AF 96/97, PM 995) on diverse aquatic organisms.
• Employed multiple ecotoxicological endpoints and test methods.
• Calculated PNEC values for each GO type.

Main Results:

• Ecotoxicity varied significantly based on test organism, endpoint, and method.
• Toxicity was dependent on nGO concentration, characteristics, and exposure duration.
• Estimated PNEC values were 8 ng/L for GO AF 96/97 and 4 ng/L for GO PM 995.

Conclusions:

• A comprehensive ecotoxicity toolkit is necessary for accurate nanomaterial risk assessment.
• The tested nGOs (AF 96/97 and PM 995) do not pose an environmental risk in aquatic environments.
• Findings support a case-by-case approach for evaluating graphene-based material safety.