The diverse toxic effect of SiO2 and TiO2 nanoparticles toward the marine microalgae Dunaliella tertiolecta

• Published in: Environmental science and pollution research international Vol. 22; no. 20; pp. 15941 - 15951
• Main Authors: Manzo, S., Buono, S., Rametta, G., Miglietta, M., Schiavo, S., Di Francia, G.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-10-2015; Springer Nature B.V
• Subjects: Aggregates; Algae; Aquatic environment; Aquatic microorganisms; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Chlorophyta - drug effects; Dunaliella tertiolecta; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental degradation; Environmental Health; Environmental impact; Industrial applications; Microalgae; Microalgae - drug effects; Nanomaterials; Nanoparticles; Nanoparticles - toxicity; Nanotechnology; Particle size; Plankton; Population growth; Research Article; Seawater; Seawater - chemistry; Sedimentation & deposition; Sediments; Silica; Silicon dioxide; Silicon Dioxide - chemistry; Silicon Dioxide - toxicity; Titanium; Titanium - chemistry; Titanium - toxicity; Titanium dioxide; Toxicity; Volvocida - drug effects; Waste Water Technology; Water Management; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - toxicity; Water Pollution Control; Italy; SiO; Marine microalgae; TiO; Nanoparticle; Seawater; SiO2; Dunaliella tertiolecta; TiO2
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-015-4790-2

Nanoparticles (NPs) are widely used in many industrial applications. NP fate and behavior in seawater are a very important issue for the assessment of their environmental impact and potential toxicity. In this study, the toxic effects of two nanomaterials, silicon dioxide (SiO
2
) and titanium dioxide (TiO
2
) NPs with similar primary size (~20 nm), on marine microalgae
Dunaliella tertiolecta
were investigated and compared. The dispersion behavior of SiO
2
and TiO
2
NPs in seawater matrix was investigated together with the relative trend of the exposed algal population growth. SiO
2
aggregates rapidly reached a constant size (600 nm) irrespective of the concentration while TiO
2
NP aggregates grew up to 4 ± 5 μm. The dose–response curve and population growth rate alteration of marine alga
D. tertiolecta
were evaluated showing that the algal population was clearly affected by the presence of TiO
2
NPs. These particles showed effects on 50 % of the population at 24.10 [19.38–25.43] mg L
−1
(EC50) and a no observed effect concentration (NOEC) at 7.5 mg L
−1
. The 1 % effect concentration (EC1) value was nearly above the actual estimated environmental concentration in the aquatic environment. SiO
2
NPs were less toxic than TiO
2
for
D. tertiolecta
, with EC50 and NOEC values one order of magnitude higher. The overall toxic action seemed due to the contact between aggregates and cell surfaces, but while for SiO
2
a direct action upon membrane integrity could be observed after the third day of exposure, TiO
2
seemed to exert its toxic action in the first hours of exposure, mostly via cell entrapment and agglomeration.