Carbon nanomaterial interactions with larval and adult fruit flies

摘要

The scientific study of nanomaterial behavior in the natural environment is in the very early stages. Here we study the interaction of carbon nanomaterials with the model organism Drosophila, the fruit fly. Drosophila larvae were exposed to a panel of carbon nanomaterials (carbon black, fullerenes, single- and multi-walled carbon nanotubes) uniformly suspended in larval food. Carbon nanomaterials are taken up by Drosophila larvae and sequestered in the adults to produce optically dark tissue observable in visible light microscopy. The nanomaterials were found to be non-toxic, however, even at very high doses sufficient to render the larval food optically dark. Upon extending the study to adult exposures, we made the surprising finding that some carbon nanomaterials adhere to the external surface of Drosophila to such a degree that they overwhelm natural cleaning mechanisms leading quickly to whole-body coverage, impaired locomotor function, and early death. Highly significant differences are observed across the carbon nanomaterial panel, which can be attributed to the size and internal structure of aggregates. At lower doses, nanoparticle adhesion and self-cleaning leads to active transport of the nanomaterials from contaminated to initially clean compartments of the test container. The implications of these results for the health of organisms, ecosystems, and for the environmental transport of nanoparticles will be discussed.