At the National Science Foundation-funded Center for Environmental Implications of Nanotechnology (CEINT), headquartered at Duke University, scientists and engineers are researching how nanoscale materials affect living things. One of CEINT's main goals is to develop tools that can help assess possible risks to human health and the environment. A key aspect of this research happens in mesocosms, which are outdoor experiments that simulate the natural environment. These simulated wetlands in Duke Forest serve as a test bed for exploring how nanomaterials move through an ecosystem and impact living things. Part of the “Science Nation” series.