Assessment of titanium dioxide nanoparticle effects on living organisms
V. I. Polonskiy, A. A. Asanova
Section: Theoretical problems of ecology
Nanoparticles causing an unprecedented type of industrial pollution directly affect on all objects of the environment and
therefore on all types of living organisms. So, these risks have to be evaluated. This review analyzes the world literature about
effects of titanium dioxide nanoparticles on living organisms of various habitats. Currently, ecotoxicity issues of engineered
nanoparticles are studied using bioassays with cell cultures and test organisms. The most commonly used test objects for
toxicity assessment of nanoparticles are unicellular algae, water crustaceans, plants, mammalian and human cells. It has been
established that the most sensitive organisms to titanium dioxide nanoparticles are unicellular algae and water crustaceans,
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values were observed at a concentration of 1 mg/L. This suggests that aquatic ecosystem is one of the most vulnerable
objects of the environment to nanoparticles. The high sensitivity of these organisms places them on a par with very promising
biotest assays for quality monitoring of the environment which is contaminated with silver nanoparticles. Titanium dioxide
nanoparticles have both positive and negative or neutral effects upon plants and these effects depend on concentration. The assays
with mammalian and human cells show a negative effect of titanium dioxide nanoparticles at concentration above 100 mg/L
or have no effect at all. The size-depended toxicity analyses revealed that the less nanoparticles size was the greater toxic effect
was. In the final analysis, the responses of living organisms of various habitats to the presence of titanium dioxide nanoparticles
in the environment are insufficiently investigated. There is insufficient data in world literature about size-dependent toxicity
of these nanoparticles to various organisms. These issues require further study.