"What we found was actually a little bit surprising," Colman says. "We added lower concentrations [of silver] to a more complex system, but rather than find no measurable effect, we found that the silver nanoparticles significantly altered the plant growth, microbial biomass and microbial activity."
As to how the nanoparticles impact plant growth, Colman says his guess it that "partly they are impacting the soil microorganisms directly, partly they are impacting the plants directly, and no doubt the microbes are having impacts on the plants…that could directly influence how the plants are growing. We are doing more work to try to discern that a little bit better."
Next, the team plans to investigate the effects of nanoparticles in a controlled wetland ecosystem, complete with algae, aquatic plants, microbes, insects, zooplankton and fish.
"The exciting part about this work is that we have a chance to get in early on studying what could be a potential problem. Typically, as ecologists we document the effects of things such as DDT after the fact, after it's had widespread effects."