Silver is a rare element occurring naturally as a pure metal and in ores. It is released into the air and soils through natural weathering and through the processing of ore, steel refining, combustion of fossil fuels, and incineration of municipal waste. The general population is exposed to silver through ingestion of drinking water and food. Foods with high silver content include seafood from areas near sewerage outflows and industrial sources and crops grown in areas with high ambient soil levels.
Bioaccumulation occurs in filter feeding seafood, but reliable data on food-chain bioaccumulation is not available.
There are no known acute effects of exposure to silver metal; but some silver compounds, such as oxides and nitrates, are irritants. With chronic exposure, silver binds to sulphhydryl groups on proteins and can lead to darkening of the skin, particularly sun exposed skin (argyria), and deposition in the cornea (argyrosis). Nephrotoxicity has been reported. Elimination is primarily through the faeces.
Plasma silver levels are an indicator of recent exposure irrespective of the route. Silver acts as an antibacterial agent and silver infused dressings are often used to treat some skin conditions and burns.
Colloidal Silver is sometimes taken as a medicine, which, if taken excessively, will increase the plasma silver levels.
Urine silver is a less reliable indicator of exposure. Intermediate and long-term exposure to silver may be determined by monitoring plasma silver levels.
Lipids/Trace Metals
SAG
Gross haemolysis OK, gross lipemia OK, gross icterus OK
Ambient 28 days, refrigerated (preferred) 28 days, frozen 28 days
5 days
7635