Elemental silver is well-known for its anti-microbial and other alleged health benefits. Several companies sell silver to consumers for ingestion to allegedly fight all types of health problems ranging from allergies, to acne, and even cancer (purportedly). The practice, of course, is not approved by the FDA so manufacturers cannot make explicit claims regarding the purported health benefit of these products. Product labels must also explain the products do not have FDA approval.
Unfortunately, as one man who is highlighted on FoxNews.com recently learned the hard way, eat or drink enough elemental silver (a whole lot) and you might turn blue . . . or gray . . . permanently. Many claim argyria — the name for this unusual condition — is a nothing more than a myth or a fable. However, it is well-documented in scientific literature. Thankfully, although permanent, it is not otherwise considered "harmful" to one’s health.
Interesting (with a small "i") you say . . . but how does this possibly relate to nanotechnology???
Several neutracutical products claim to use nanosilver particles as the newest and best way to deliver elemental silver to the body. One claimed benefit is that because it uses nanoscale particles, the liquid appears clear (instead of brown). You can find some of these products on Woodrow Wilson International Center for Scholar’s Project on Emerging Nanotechnologies consumer product inventory.
Personally, I would never drink the stuff, but if enough people do, there may be new cases of argyria accompanied by inevitable plaintiffs lawsuits. It would be unfortunate if more "traditional" uses of nanosilver are somehow tarnished in the process. If you watch the video clip on Fox, the poor guy still swears by the stuff (and "yes," he is filmed drinking a clear version).