Toxicity of copper oxide nanoparticle suspensions to aquatic biota.
Toxicity effects induced by nanosuspensions of CuO (<50 nm; Sigma-Aldrich) on macrophytic algae cells of Nitellopsis obtusa (96-h median lethal concentration [LC50]), microphytic algae Chlorella (30-min median inhibitory concentration [IC50]), shrimp Thamnocephalus platyurus (24-h LC50), and rotifer Brachionus calyciflorus (24-h LC50) were investigated. No substantial differences between the effects of nonsonicated and sonicated nCuO suspensions were observed. The particle size distribution analysis accomplished by the laser diffraction technique at suspension concentration from 3 to 100 mg/L revealed rapid (within 5 min) reagglomeration of the particles after the sonication. The observed adverse effects on N. obtusa cells may be attributed to nanoparticles per se, but not to ionic Cu, because neither chemical analysis nor biological testing (algae survival in the supernatants of suspensions) confirmed the presence of cupric ions in toxic amounts. Contrary to ionic Cu form, nCuO delayed the initial phase of N. obtusa cell membrane depolarization. Lethality tests with rewash demonstrated that the least used 5-min exposure in 100 mg/L nCuO sonicated suspension induced 70% mortality in charophyte cells after 8 d, whereas the rewash after a short exposure to a noticeably toxic concentration of Cu(2+) prevented cell mortality. The obtained data suggested the possible influence of a thick charophyte cell wall on the dynamics of nanotoxicity effects.
Institute of Botany of the Nature Research Centre, Vilnius, Lithuania. levonas.manusadzianas@botanika.lt
Levonas
L
Manusadžianas
Celine
C
Caillet
Louis
L
Fachetti
Brigita
B
Gylytė
Reda
R
Grigutytė
Sigita
S
Jurkonienė
Rolandas
R
Karitonas
Kazys
K
Sadauskas
Fabien
F
Thomas
Rimantas
R
Vitkus
Jean-François
JF
Férard
D000818:Animals; D033202:Anostraca / Q000187:drug effects; D058448:Biota; D002462:Cell Membrane / Q000187:drug effects; D003300:Copper / Q000633:toxicity*; D007477:Ions / Q000633:toxicity; D007928:Lethal Dose 50; D008564:Membrane Potentials / Q000187:drug effects; D053758:Nanoparticles / Q000633:toxicity*; D010316:Particle Size; D012403:Rotifera / Q000187:drug effects; D013010:Sonication; D013535:Suspensions / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D007477:Ions; D013535:Suspensions; D014874:Water Pollutants, Chemical; D003300:Copper; C000520:cuprous oxide