SILVER NANOPARTICLES AND SILVER IONS BIOAVAILABILITY. BIOACCUMULATION IN CAPITELLA TELETA ORGANISM

The goal of the project is to investigate the bioavailability of silver ions (Ag+) released by silver nitrates and silver nanoparticles (Ag NPs), in three different medias: milliq water, seawater and sediment, and their bioaccumulation potential using the marine polychaete Capitella teleta as testing organism. The DGT performance tests were carried out to investigate the avaibility of silver ions in the three above mentioned medias, and concentration of silver ions in worms were used to calculate the bioaccumulation factor of silver ions in seawater and sediments. Growth rate of C. teleta was another endpoint monitored during our project. DGT measurements show that there is more labile Ag+ released from Ag NPs in milliq water than in seawater.The worms were exposed to silver ions, and silver nanoparticles in sediment and seawater for 16 days, and DGT performance lasted also 16 days. After exposure the concentrations of ions in organisms were measured by using an atomic absorption spectrometer (AAS). The observations showed that organisms in seawater were dead after one day of exposure, while the AAS measurements showed that the concentration of ions in organisms did not varied a lot with Ag+ and Ag NPs. BAF was smaller with AgNPs than with Ag+. BAFs in both cases are less than 1, it means that for this specie silver is bioavailable but not bioaccumulated. Growth rate of Capitella teleta is not not affected by the presence of Ag+ and AgNPs.