Nanoparticles of silver are in more than 200 different products on the market as anti-microbial agents, but scientists are now questioning whether the practice is safe for our environmental and personal health. Nanoparticles, silver in particular, get washed down the drain and into our waterways, exposing fish and other aquatic life and raising big concerns about the potential effects.
Silver nanoparticles are smaller than a virus (nanoparticles measure less than 100 nanometers in length), and are not removed by our sewage treatment systems. New research is showing that these nanoparticles can mutate and kill the embryos of fish once they enter the water ecosystems.
“I think we jumped the gun by creating such large volumes of nanoparticles. We should take more time and really look at these new nano-systems before we start to throw them into personal products and shoot them into these ecosystems.” – University of Utah researcher Darin Furgeson
Furgeson is a professor of pharmaceutical sciences who exposed zebrafish embryos to silver nanoparticles in a lab, and found that some were left with dramatic mutations and some died outright. The nanosilver particles caused malformations in their eyes, tails, and swim bladders, and some developed fluid around the heart that causes congestive heart failure.
“Zebrafish have similar tissues and organs to us. They don’t have lungs, but they do have a liver, kidneys and heart – though it is only two chambered – and they have a blood-brain barrier.” – Ferguson
In the 1970s, ionic silver from wastewater polluted San Francisco Bay at concentrations that prevented the mussels from reproducing – silver is one of the most toxic heavy metals.
“The silver that went into wastewaters when millions of people had their photographs developed taught us that small additions of silver to the environment make a big difference.” – Dr. Samuel Luoma, a former U.S. Geological Survey senior researcher
Other recent research has shown that some metal nanoparticles can damage DNA or kill cells, and one new study found that nanoparticles can cross into the womb through the placenta, raising the issue of human health effects. According to the fish study, different materials have different effects. Only silver nanoparticles were toxic to fish embryos, though both gold and silver nanoparticles were tested. Gold particles did not have an effect on the embryos.
The new study may have large implications, as the nanotechnology industry is booming, and is projected to hit a trillion dollars by 2015. The number of consumer products using nanotechnology has increased about 380% in the last 3 years, according to the Project on Emerging Nanotechnologies.
“The same special properties that make nanoscale materials useful are also properties that may cause some nanoscale materials to pose potential risks to humans and the environment, under specific conditions. At this point not enough information exists to fully assess these risks.” – EPA report on nanoparticles