Silver Nanoparticles in Consumer Products
Silver ions have been shown to have anti-microbial properties. And so silver has been popping up in all sorts of consumer products, with ions added to everything from tissues to t-shirts, hand sanitizers, socks, children’s toys, lotion, fabric softener, pacifiers — as well as toothbrushes and toothpaste.
Before the advent of antibiotics, silver was essential in fighting infections. Even today, many wound dressings are infused with antimicrobial silver ions.
|Ingesting Silver Can Turn Your Skin Blue
Argyria is what happens when a person is exposed to large amounts of silver. It’s not clear if it’s linked to health problems, but the cosmetic consequences can be dramatic: exposure to silver can cause your skin to turn blue!
He’s even been featured on The Today Show: ‘Blue man’ is still a man of a different color
Modern medicine still isn’t sure exactly how silver gets its anti-bacterial properties, nor what the risks of over-exposure might be. Silver does build up in the body, but it hasn’t been definitively linked to any health problems. (Well, excessive silver can cause your skin to turn blue – see sidebar – but that’s all that’s been proven.)
First, let’s make a few important clarifications, because not all silver is the same.
- Elemental silver is not essential to the human body, but it has not been shown to be toxic.
- Silver ions (Ag+) have antibacterial properties.
- Colloidal silver gained ground in the 90’s as an alternative medicine treatment. Though available at health food stores, the FDA prohibits marketing these products as medically effective. Most (but not all!) of these products contain silver colloids – small particles of silver.
- Silver nano-particles are smaller than silver colloids – and smaller than bacteria or viruses. Their tiny size offers greater surface area and can release more silver ions, enhancing the potency.
But is potency a good thing or a bad thing?
In fact, silver nanoparticles have gotten so potent that environmentalists have become concerned. Now present in hundreds of products, it’s inevitable that some nano-silver will wash down the drain (where it won’t be removed by sewage systems) and into the ecosystem (where we’re not able to detect it).
Researchers have shown that silver nanoparticle exposure causes mutations in fish (Scientific American). At higher concentrations all fish embryos die; at lower concentrations, they come out grossly mutated.
The really troubling thing is that it’s not clear what effect they have on the human body. While it’s generally accepted that elemental silver doesn’t harm the human body, silver nanoparticles behave differently, and their long-term effects haven’t been studied.
What do you think?
Next week: How is silver nanotechnology being applied to dentistry?