2 Dec, 2009 08:15 am
I was astonished when recently, during a discussion about hazards of mineral nanoparticles, a learned colleague of mine took a bottle of colloid silver from his bag and drunk from it to illustrate the safety of nanotechnology.
My colleague stated that he regularly drunk silver water when he hade a sore throat. Colloid silver solutions do indeed contain silver nanoparticles. And there are good arguments for the medical use of silver nanoparticles in special cases. Such special cases include professionally used dressings for burns and some wounds, to suppress pathogenic bacteria. But to me, drinking a colloid silver solution against a sore throat is as stupid as the indiscriminate use of antibiotics, which does more harm, by selective pressure favoring resistant pathogens, than good. And the risk that regular intake of colloidal silver can give rise to argyria and damage to liver and kidney has not gone away. I gave off negative noise, but my learned colleague was not convinced. He felt fine.
Alerted by this, I have looked around for ‘modern’applications of nanosilver. Indeed, ‘silver water’is currently promoted on the Internet. In my country it is advertized as a ‘natural antibiotic’ and it is promoted for use against more than 300 types of illness.
But there are many more applications of silver nanoparticles. The website of the Woodrow Wilson International Centre gives an interesting survey thereof (1). Increasingly one can find textiles, such as socks, shirts, caps, jackets, gloves and underwear, with nanosilver in the shops. Experiments with washing by the way show that silver may be rapidly lost from socks and other textiles sold in shops (2).
The company Samsung sells washing machines and freezers dispensing nanosilver. Cosmetics producers use nanosilver in products for skin care, baby care and oral hygiene. There are cleaning products for bathroom, kitchen and toilets with silver nanoparticles And there are several applications in food products, such as food supplements and food packaging materials.
I feel that the proliferation of products provided with silver nanoparticles is stupid. Lawmakers should firmly restrict the application of nanosilver to essential uses, such as the treatment of some burns and wounds.
(2) T.M. Benn, P. Westerhoff, 2008. Nanoparticlesilver released into water from commercially available sock fabrics. Environmental Science & Technology 42:4133-4139 & 7025-7026