Algal testing of titanium dioxide nanoparticles—Testing considerations, inhibitory effects and modification of cadmium bioavailability

Abstract The ecotoxicity of three different sizes of titanium dioxide (TiO2 ) particles (primary particles sizes: 10, 30, and 300 nm) to the freshwater green alga Pseudokirchneriella subcapitata was investigated in this study. Algal growth inhibition was found for all three particle types, but the p...

Full description

Saved in:
Bibliographic Details
Published in:Toxicology (Amsterdam) 2010-03, Vol.269 (2), p.190-197
Main Authors: Hartmann, N.B, Von der Kammer, F, Hofmann, T, Baalousha, M, Ottofuelling, S, Baun, A
Format: Article
Language:English
Subjects:
Algae
Bioavailability
Biological and medical sciences
Cadmium
Cadmium - chemistry
Cadmium - metabolism
Cadmium - toxicity
Chemical and industrial products toxicology. Toxic occupational diseases
Chlorophyta - drug effects
Chlorophyta - growth & development
Chlorophyta - metabolism
Dose-Response Relationship, Drug
Ecological risk assessment
Ecotoxicology
Emergency
Medical sciences
Metal Nanoparticles - chemistry
Metal Nanoparticles - toxicity
Metal Nanoparticles - ultrastructure
Metals and various inorganic compounds
Nanomaterials
Nanoparticles
Nanostructure
Particle Size
TiO 2
Titanium - chemistry
Titanium - toxicity
Titanium dioxide
Toxicity
Toxicity Tests - methods
Toxicology
Water Pollutants, Chemical - chemistry
Water Pollutants, Chemical - toxicity
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract The ecotoxicity of three different sizes of titanium dioxide (TiO2 ) particles (primary particles sizes: 10, 30, and 300 nm) to the freshwater green alga Pseudokirchneriella subcapitata was investigated in this study. Algal growth inhibition was found for all three particle types, but the physiological mode of action is not yet clear. It was possible to establish a concentration/dose–response relationship for the three particle sizes. Reproducibility, however, was affected by concentration-dependent aggregation of the nanoparticles, subsequent sedimentation, and possible attachment to vessel surfaces. It is also believed that heteroaggregation, driven by algal exopolymeric exudates, is occurring and could influence the concentration–response relationship. The ecotoxicity of cadmium to algae was investigated both in the presence and absence of 2 mg/L TiO2 . The presence of TiO2 in algal tests reduced the observed toxicity due to decreased bioavailability of cadmium resulting from sorption/complexation of Cd2+ ions to the TiO2 surface. However, for the 30 nm TiO2 nanoparticles, the observed growth inhibition was greater than what could be explained by the concentration of dissolved Cd(II) species, indicating a possible carrier effect, or combined toxic effect of TiO2 nanoparticles and cadmium. These results emphasize the importance of systematic studies of nanoecotoxicological effects of different sizes of nanoparticles and underline the fact that, in addition to particle toxicity, potential interactions with existing environmental contaminants are also of crucial importance in assessing the potential environmental risks of nanoparticles.
ISSN:0300-483X
1879-3185
DOI:10.1016/j.tox.2009.08.008