Silver nanoparticles have been incorporated into a wide variety of consumer products, ideally acting as antimicrobial agents. Silver exposure has long been known to cause toxic effects to a wide variety of organisms, making large scale production of silver nanoparticles a potential hazard to environmental systems. Here we describe the first evidence that an organism may be able to sense manufactured nanoparticles in a complex, environmentally relevant exposure and that the presence of nanoparticles alters the organism's behavior. We found that earthworms (Eisenia fetida) consistently avoid soils containing silver nanoparticles and AgNO3 at similar concentrations of Ag. However, avoidance of silver nanoparticles occurred over 48 h, while avoidance of AgNO3 was immediate. It was determined that avoidance of silver nanoparticles could not be explained by release of silver ions or any changes in microbial communities caused by the introduction of Ag. This leads us to conclude that the earthworms were in some way sensing the presence of nanoparticles over the course of a 48 h exposure and choosing to avoid exposure to them. Our results demonstrate that nanoparticle interactions with organisms may be unpredictable and that these interactions may result in ecologically significant effects on behavior at environmentally relevant concentrations.
|Number of pages||12|
|State||Published - Mar 2011|
Bibliographical noteFunding Information:
Acknowledgments We thank M. Lacey, E. Harding and L. Wang for assistance with sample processing, S. Hunyadi for providing some of the nanoparticles studied, J. Kupper for performing FAME analysis and J. Nelson for assistance with GC analysis. Major funding for this research was provided by the United States Environmental Protection Agency (U.S. EPA) Science to Achieve Results Grant RD 833331. This material is also based in part upon work supported by the National Science Foundation (NSF), the U.S. EPA and the Center for the Environmental Implications of NanoTechnology (CEINT) EF-0830093. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the NSF or the EPA. This work has not been subjected to EPA review and no official endorsement should be inferred.
- Earthworm behavior
- Silver nanoparticle
- Soil environment
ASJC Scopus subject areas
- Management, Monitoring, Policy and Law
- Health, Toxicology and Mutagenesis