Nanoparticles in the aquatic environment: Particle characterization and effects on organisms

Sammanfattning: This thesis explores the effect of nanomaterials in aquatic systems. We have studied the effects of size and surface chemistry for nanoparticles as well as the effect <i>Daphnia magna</i> filtration has on nanomaterials. We show a size dependent toxicity for amino modified polystyrene nanoparticles to <i>Daphnia</i> as well as that the surface chemistry for gold nanoparticles affects the size of the particles in different media. We also show that <i>Daphnia</i> filtration influence nanowire (NW) fragmentation in a diameter dependent manner, 40 nm NWs are fragmented into shorter pieces than those with 80 nm diameter. <br/>We delivered plastic nanoparticles to fish through a natural food chain, from algae through <i>Daphnia</i> and show that the nanoparticles are transported through the food chain and affect the fish behavior, metabolism and brain. <br/>Moreover, we show that nanomaterials can pass biological barriers. We exposed <i>Daphnia magna</i> to NWs with two different diameters (40 and 80 nm respectively) and similar lengths and found that the NWs can pass the epithelium membrane and that the 40 nm NWs do it to a greater extent. We also show that plastic nanoparticles transported through a food chain can pass the blood-brain barrier in fish. This thesis explores the effect of nanomaterials in aquatic systems. We have studied the effects of size and surface chemistry for nanoparticles as well as the effect <i>Daphnia magna</i> filtration has on nanomaterials. We show a size dependent toxicity for amino modified polystyrene nanoparticles to <i>Daphnia</i> as well as that the surface chemistry for gold nanoparticles affects the size of the particles in different media. We also show that <i>Daphnia</i> filtration influence nanowire (NW) fragmentation in a diameter dependent manner, 40 nm NWs are fragmented into shorter pieces than those with 80 nm diameter. <br/>We delivered plastic nanoparticles to fish through a natural food chain, from algae through <i>Daphnia</i> and show that the nanoparticles are transported through the food chain and affect the fish behavior, metabolism and brain. <br/>Moreover, we show that nanomaterials can pass biological barriers. We exposed <i>Daphnia magna</i> to NWs with two different diameters (40 and 80 nm respectively) and similar lengths and found that the NWs can pass the epithelium membrane and that the 40 nm NWs do it to a greater extent. We also show that plastic nanoparticles transported through a food chain can pass the blood-brain barrier in fish.