Single-Walled Carbon Nanotubes Toxicity to the Freshwater Amphipod Hyalella Azteca: Influence of to the Freshwater Amphipod Sediment and Exposure Duration.

Messika Revel,Michel Fournier,Pierre Yves Robidoux

doi:10.4081/xeno.2015.5086

Abstract

Carbon nanomaterials are present in various industrial applications and therefore their release into the environment including freshwater ecosystem is expected to increase. The aim of the present study was to investigate the influence of several parameters on the toxicity of single-walled carbon nanotubes (SWCNT) to the freshwater amphipod, Hyalella azteca. The effect of period of exposure, sediment presence and possible impurities released during SWCNT preparation on survival and/or growth of such organism was evaluated. We measured a reduction of survival at concentrations ranging from 10 to 40 mg/L after 96-h exposure, while no mortality was observed with the same concentrations and in the presence of artificial sediment after 14 days of exposure. It is possible that SWCNT are adsorbed on the organic matter from the artificial sediment leading to a decrease of SWCNT bioavailability. The survival and growth toxicity tests revealed a stronger effect at 28 days compared to the 14 days of exposure, and full mortality of organisms at 1000 mg/L for both exposure times. The presence of SWCNT in the gut of survived organisms was observed. The present study demonstrates that the interaction with sediment should be considered when carbon nanotubes toxicity through water exposure is investigated.

Highlights

The hydrophobic nature of single-walled carbon nanotubes (SWCNT) relates to their tendency to sink in water
The of 50-200 mm), 20% kaolinite clay, and 0.1% of isms taken at the beginning of each test was chemical properties of dry SWCNT were meas- CaCO3 to adjust sediment pH.[28]
As ured using thermo-gravimetric analysis (TGA) were conducted in 300 mL polypropylene recommended by the guidelines, a test was and the ratio of the G-band (~1580 cm−1) to the beakers containing 100 mL sediment and 160 considered invalid if the survival for the con

Summary

Introduction

In the aquatic environment, natural coatings such as organic matter can increase the carbon nanotubes dissolution by covering their surface.[14] transmission electron microscopy. Is frequently used for toxicity studies The aim of this study was to investigate the because of its ubiquitous presence in the influence of period of exposure, sediment. Introduction freshwater environment, contact with sedi- presence and possible impurities released durment, ecological importance and ease of cul- ing SWCNT preparation on the toxicity of ture in the laboratory.[23] A previous study SWCNT to the freshwater amphipod H. azteca. Single-walled carbon nanotubes (SWCNT) demonstrated that purified or as-produced car- The objectives were: i) to compare the effects are hollow graphene cylinders with size of bon nanomaterials could diminish the survival of acute and chronic exposure; ii) to investi-

Objectives

Methods

Findings

Conclusion