Photo by erazofischer
Your odor-eating undies may shield the wider world from your suds-eschewing proclivities, but the silver nanoparticles embedded within could migrate into the environment, strip the soil of beneficial microorganisms, and impede plant growth, according to a new study. Although the findings, presented earlier this month at the 95th Annual Meeting of the Ecological Society of America, don’t postulate any end-of-days scenarios, they do suggest that we cast a gimlet eye at that nanotechnology-impregnated materials that are swiftly gaining popularity.
NO NO NANO?
Ionic silver has long been touted for its antimicrobial prowess, with broad applications such as wound dressing, bacteria-neutralizing home appliances, odor-resistant threads, and even germ-fighting plush animals, although companies in the United States are not required to disclose the presence of nanomaterials.
Silver has long been touted for its antimicrobial prowess, from wound dressing to germ-fighting toys.
Less understood, however, is the impact nanoparticles have on the environment at large, mainly because most studies focus on one species of bacteria: Escherichia coli. “It’s really hard to extrapolate from these single-species studies in simple environments to what will inevitably happen when these particles enter the environment,” Ben Colman, a postdoctoral researcher at Duke University who led the study, tells Scientific American.
One of the likeliest routes for nano-sized particles to enter the environment? Wastewater, which precipitates into sewage sludge at treatment plants. Since the 1990s, government agencies have disposed of the unsavory goop by selling it in the form of heat-dried “lawn-and garden enhancements” to farmers—and there’s the rub. Because plants depend on soil-dwelling microorganisms to flourish, the microbe-killing potency of silver nanoparticles could stunt their growth.
Plants need soil-dwelling microorganisms to flourish, so microbe-killing silver nanoparticles could stunt growth.
So far, the studies performed by Duke researchers back this theory. Silver nanoparticles, notes Coleman, “significantly altered the plant growth, microbial biomass, and microbial activity.” Still, the specific pathway in which nanoparticles impact plant maturation is anyone’s guess.
“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,” says Coleman. “We are doing more work to try to discern that a little bit better.”
[Via Scientific American]