Exposure-Related Health Effects of Silver and Silver Compounds: A Review
I suggest you jump down to DISCUSSION synopsis occupational exposure to silver (metallic silver - predominantly through inhalation and insoluble silver) is considered a workplace hazardous material, however as noted, soluble silver compounds (including those taken as dietary supplements) are absorbed much more readily and can accumulate in the body at even lower amounts.
But more importantly, there have been no scientific studies that show that orally ingesting colloidal silver cures or prevents any of the many illnesses its peddlers purport. But even if in most cases (absent ingesting significant amounts which can and does most definitely causes argyria and kidney damage and neurological problems such as seizures) even in lower to moderate does, it does no significant harm, by making claims that it is some sort of wonder drug that will cure and or prevent a whole host of ills (effective against cancer, staph, strep, influenza, general body infections, inflammation, impaired immune system, fungus toxicity, tonsillitis, Meniere's symptoms, whooping cough, shingles, syphilis, cholera, and malaria, AIDs and most recently Ebola), it may prevent people from seeking legitimate and effective treatment or give them a false sense of security thinking that the colloidal silver will protect them.
Is silver responsible for the permanent nervous system damage of some folks who have spent time in old fashioned photography dark rooms?