Silver In Drinking Water – World Health Organization Guidelines
In this report the World Health Organization discusses the maximum allowable amount of silver allowed in drinking water, and reports that the “biological half-life (of silver) in humans ranges from several days to 50 days. According to the report, the liver plays the main role in the elimination of silver from the body.
And most ingested silver is excreted in the feces, with cumulative excretion rates between 90-99%. The report states, “The only known clinical picture of chronic silver intoxication is that of argyria, a condition in which silver is deposited on skin and hair, and in various organs following occupational or iatrogenic exposure to metallic silver and its compounds, or the misuse of silver preparations.”
The report concludes, “On the basis of present epidemiological and pharmacokinetic knowledge, a total lifetime oral intake of about 10 g of silver can be considered as the human NOAEL [i.e., No Observable Adverse Effect Level]…Higher levels of silver, up to 0.1 mg/litre (a concentration that gives a total dose over 70 years of half the human NOAEL of 10 g), could then be tolerated without risk to health.”