Nanosilver
Nanosilver
But the expansion of nanosilver into new applications may also contribute to unique risks. Looming large among them is the possibility that widespread use of nanosilver will contribute to silver resistance in bacteria, as has happened with other common antibiotics including penicillin, tetracycline, and triclosan.
Nanosilver impregnated into consumer products and coatings will slowly, through laundering, be abraded from its substrate material at varying volumes and over varying periods of time, depending on concentrations in the material and the strength with which it is bonded, says Bernd Nowack of the Swiss Federal Laboratories for Materials Science and Technology. In consumer textiles, he notes, the industry standard is for the antimicrobial effect to persist over at least 50 washes, although some research suggests nanosilver can leach from certain products within the first few washes.
Critics have questioned whether it's wise to dispatch such a powerful weapon against bacteria in everyday contexts where bacteria pose a relatively minor concern. "It's one thing if we're using a little bit of nanosilver in the shoes of diabetics," says Jaydee Hanson, policy director for the nonprofit International Center for Technology Assessment.
"It's another thing if you're putting it in all underwear, all socks, every bed, every bed sheet. It's a huge, exponential increase in the amount of nanosilver we're putting into the environment."
–Jaydee Hanson
International Center for Technology Assessment
Gregory Crocetti, a Melbourne-based microbiologist who has worked on Friends of the Earth Australia's nanosilver campaign, takes a stricter position. "Nanosilver should remain in a hospital setting only," he says. "Those clinical uses will be diminished by completely hysterical and frivolous uses in homes. … Nanosilver has a high likelihood of promoting not just silver resistance but also antibiotic resistance because of the process of co-selection." Co-selection occurs when bacteria challenged with one antimicrobial find a resistance gene to it by swapping DNA with bacteria that are resistant to a different antimicrobial.
How Much is Too Much?
But the expansion of nanosilver into new applications may also contribute to unique risks. Looming large among them is the possibility that widespread use of nanosilver will contribute to silver resistance in bacteria, as has happened with other common antibiotics including penicillin, tetracycline, and triclosan.
Nanosilver impregnated into consumer products and coatings will slowly, through laundering, be abraded from its substrate material at varying volumes and over varying periods of time, depending on concentrations in the material and the strength with which it is bonded, says Bernd Nowack of the Swiss Federal Laboratories for Materials Science and Technology. In consumer textiles, he notes, the industry standard is for the antimicrobial effect to persist over at least 50 washes, although some research suggests nanosilver can leach from certain products within the first few washes.
Critics have questioned whether it's wise to dispatch such a powerful weapon against bacteria in everyday contexts where bacteria pose a relatively minor concern. "It's one thing if we're using a little bit of nanosilver in the shoes of diabetics," says Jaydee Hanson, policy director for the nonprofit International Center for Technology Assessment.
"It's another thing if you're putting it in all underwear, all socks, every bed, every bed sheet. It's a huge, exponential increase in the amount of nanosilver we're putting into the environment."
–Jaydee Hanson
International Center for Technology Assessment
Gregory Crocetti, a Melbourne-based microbiologist who has worked on Friends of the Earth Australia's nanosilver campaign, takes a stricter position. "Nanosilver should remain in a hospital setting only," he says. "Those clinical uses will be diminished by completely hysterical and frivolous uses in homes. … Nanosilver has a high likelihood of promoting not just silver resistance but also antibiotic resistance because of the process of co-selection." Co-selection occurs when bacteria challenged with one antimicrobial find a resistance gene to it by swapping DNA with bacteria that are resistant to a different antimicrobial.