(NHI Nanoblog)A team of researchers at Virginia Tech are adding to the growing body of evidence suggesting that nanosilver — which is growing in popularity as an anti-bacterial agent — is invading our water and sewer system.
Courtesy Michael Hochella
Led by Michael Hochella (pictured), a geosciences professor, the team used an electron microscope to pinpoint nano-sized silver sulfide particles in the end-stage sludge of a municipal water plant (in other words, they found the silver after the sewage had been treated).
Their paper, which is published in the October issue of the journal Environmental Science & Technology, echoes findings of previous studies, which show bits of the material can turn up in the water when you wash socks or a T‑shirt impregnated with nanosilver, as well as in artificial sweat. As Sarah Webb reports in an item posted at Chemical & Engineering News, Hochella thinks that the nanosilver bits are binding with sulfur in the sluge, creating a new material.
Hochella adds that this work underscores some of the complexity in studying environmental effects of nanoparticles: “What we start with is not what ends up in nature.”
Nanosilver remains largely unregulated, although the U.S. Environmental Protection Agency is in the process of certifying one brand of the material, used in workout gear, as a pesticide.