Based on research, it appears as though there were numerous cases of argyria associated with silver over the years. Be it through ingestion, inhalation and/or direct contact. Though what's outstanding is where the events leading to the condition seemed consistent with high concentrations over long term exposure. And so I'm not quite sure if the same could be had from the exposures of the everyday items we use in our day to day lives. ie, based on the data, it appears as though argyria takes place when the exposures and/intake of silver(be it metallic or otherwise) exceeds the bodies capacity to excrete it properly. And thus, accumulation occurs. And more importantly, where it's likely that the body can manage the exposure so long as the levels remain within our ability to excrete it. Which is why the FDA published toxicity ratings based on; concentration x body weight / time.

My two cents.