Beginning in 2015, CEINT began conducting a center-wide mesocosm experiment in order gain a deeper understanding of nanoparticle effects and transport in a realistic wetland environment. While the mesocosm facilities are located at and managed by Duke University, experimental planning and efforts are spread across all CEINT institutions. We hope to answer several key questions:
- How does the nutrient level in the environment influence nanomaterial movement through the environment and biological or ecological effects?
- How are these effects influenced by nanoparticle size?
- Can we design functional assays for laboratory studies that are capable of predicting these realistic environmental responses?
This ambitious, yearlong experiment utilizes a set of 25 mesocosm boxes receiving a variety of different weekly small nanoparticle treatments. While half are enhanced with extra nutrients, every box contains the same water and soil, land and aquatic plant life, and variety of aquatic life forms. There are however several different nanomaterials used independently:
- An agricultural fungicide that utilizes copper nanoparticles
- Small ceria nanoparticles particles, similar to those used in the electronics industry for polishing
- Large ceria nanoparticles, similar to those from diesel exhaust when ceria nanoparticle fuel additives are used, which are growing in popularity in Europe
- Gold nanoparticles, while rarely find their way into the environment, are used as a model nanoparticle that does not change over time and can easily be traced through entire ecosystems
Through careful monitoring of every mini ecosystem through all 52 weeks of nanoparticle exposure and answering the key questions identified, CEINT hopes to be able to form some general rules of nanoparticle behavior in natural environments. These general rules may then help ensure the safe and responsible development of promising nanotechnologies.