Long-term effects and toxicokinetics of differently coated silver nanoparticles in the marine deposit-feeding polychaete Capitella teleta

Maria Nielsen

Studenteropgave: Speciale

Abstrakt

Wide spread use of silver nanoparticles (AgNPs) and associated release to the environment have raised environmental concern. As AgNP accumulation is believed to occur in aquatic sediments, knowledge on the effects of the particles to sediment-dwelling organisms are needed and long-term toxicity tests are in high demand. Many AgNPs are synthesized with a surface coating, which affect the surface properties and are likely to influence bioavailability and environmental fate of the AgNPs. In this study long-term effects and uptake of un-coated AgNPs and silver nitrate (AgNO3) in the polychaete Capitella teleta were investigated. AgNP uptake in C. teleta and fate in the experimental system (water, sediment, C. teleta fecal pellets and C. teleta tissue) were also studied and compared for differently coated AgNPs (un-coated, polyvinylpyrrolidone-coated (PVP) and mercaptoundecanoic acid-coated (MUDA)). In all studies C. teleta were exposed to Ag via sediment. Growth and reproduction in C. teleta were slightly affected after long-term exposure to AgNPs and AgNO3, however the effects did not follow a clear Ag form - or dose-pattern and must be investigated further. It was found that AgNO3 bioaccumulated in C. teleta to a higher degree than AgNPs. Comparing uptake and fate of the differently coated AgNPs showed a tendency that MUDA-coated AgNPs were more bioavailable to C. teleta and accumulated less in C. teleta fecal pellets compared to un-coated AgNPs. AgNPs were up-concentrated in C. teleta fecal pellets and Ag concentrations were 2.6 to 3.7 times higher in fecal pellets than in sediment for all three AgNP types. This suggest that surface coating affect behavior and uptake of AgNPs and should be considered in ecotoxicological testing. The results also indicate that sediment-dwelling organisms can influence the fate of sediment-associated AgNPs

UddannelserMiljørisiko, (Bachelor/kandidatuddannelse) Kandidat
SprogEngelsk
Udgivelsesdato30 nov. 2015
VejledereAnnemette Palmqvist

Emneord

  • Nanoparticles
  • Ecotoxicology