US EPA

157476 

Journal Article 

Aquatic ecotoxicity tests of some nanomaterials 

Velzeboer, I; Hendriks, AJ; Ragas, AM; van de Meent, D 

2008 

Yes 

Environmental Toxicology and Chemistry
ISSN: 0730-7268
EISSN: 1552-8618 

27 

9 

1942-1947 

English 

19086210 

WOS:000258325000014 

Nanoparticles of TiO2, ZrO2, AL2O3, CeO2, fullerene (C60), single-walled carbon nanotubes, and polymethylmethacrylate were tested for ecotoxic effects using one or more ecotoxicity endpoints: Microtox (bacteria), pulse-amplitude modulation (algae), Chydotox (crustaceans), and Biolog (soil enzymes). No appreciable effects were observed at nominal concentrations of up to 100 mg/L. Dilution of nanoparticle suspensions, either in ultrapure (Milli-Q) water or in natural (pond) water, led to formation of larger particles, which settled easily. (Nano)particles in water were characterized by means of atomic force microscopy, energy-dispersive x-ray analysis, inductively coupled plasma-mass spectrometry, flow cytometry, and spectrophotometry. It is concluded that the absence of ecotoxicity is the result of low concentrations of free nanoparticles in the tests, and it is suggested that colloid (in)stability is of primary importance in explaining ecotoxic effects of nanoparticles in the natural environment. 

synthetic nanoparticles; environmental fate; toxicity tests; aquatic environment