xmlui.ArtifactBrowser.SimpleSearch.filter.source:Scientific papers of the University of Pardubice. Series A, Faculty of Chemical Technology. 27/2021
ISSN:1211-5541
Abstract:
Environmental risk assessment requires to conduct standardized ecotoxicological bioassays
that can, at least, partially imitate realistic exposure scenarios. However, the study of the
ecotoxic effects of particulate materials is complicated mainly by the fact that particles have
different physical-chemical properties resulting in different distribution in the test medium in
comparison with soluble pollutants. Therefore, in this study, the agar-based experimental
system has been used to examine the toxicity of plastic microparticles to the soil decomposer
Enchytraeus crypticus. Furthermore, of interest was the effect of the presence of plastic
particles on the toxicity of gadolinium salts whose harmfulness to soil organisms is less
known. The agar-based exposure medium enabled the consistent dispersion and
agglomeration state of particles during the experiments under stable conditions with the
characterization of the particles directly in the exposure medium. Gadolinium was tested in
the form of Gd(NO3)3 and two contrast agents - Dotarem® (Acidum gadotericum) and
MultiHance® (Dimeglumi gadobenas). The polystyrene particles (65–497 μm) were
prepared by cryogenic grinding of coffee cup lids. The estimated 96h LC50 for gadolinium
was higher than 1 g kg−1 of agar, which suggests a relatively low acute toxicity to E. crypticus.
The polystyrene particles exhibited no toxicity to E. crypticus even at very high concentrations
(1–25 g kg−1 of agar) after 10 days of exposure. The survival rate, the content of
malondialdehyde in the biomass, or biomass production E. crypticus were not affected after
10-day of exposure to three different concentrations of Gd in the presence of particles.
