Filtration of biopolymer PHB particles loaded with synthetic musks does not cause significant bioaccumulation in marine mussels

The role of the biopolymer polyhydroxybutyrate (PHB, <250 µm) as a vehicle of a synthetic musks mixture (celestolide, galaxolide, tonalide, musk xylene, musk moskene and musk ketone) to Mytilus galloprovincialis was investigated. For 30 days, virgin PHB, virgin PHB+musks (6.82 µg g-1) and weathered PHB+musks, were daily spiked into tanks containing mussels, followed by a 10-day depuration period. Water and tissues samples were collected to measure exposure concentrations and accumulation in tissues. Mussels were able to actively filter microplastics in suspension but the concentration of the musks found in tissues (celestolide, galaxolide, tonalide) were markedly lower than the spiked concentration. Estimated Trophic Transfer Factors suggest that PHB will only play a minor role on musks accumulation in marine mussels, even if our results suggest a slightly extended persistence in tissues of musks loaded to weathered PHB.