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 main industrial use of silver has been in the photographic industry. 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.
Occupational exposure occurs in the primary metal industries, air conditioning and refrigeration mechanics, plumbers, welders, and those involved in processing silver nitrate and oxide for use in the photography, smelting and refining industries. Absorption is either through inhalation or oral ingestion or dermal absorption. Bioaccumulation occurs in filter feeding seafood, but reliable data on food-chain bioaccumulation is not available. Little data is available on exposure levels in humans.
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 treatment of 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, (in a study by DiVincenzo13 – 100 % of exposed workers had faecal silver above the limit of detection, but only 6 % of urine samples had detectable silver). Intermediate and long-term exposure to silver may be determined by monitoring plasma silver levels or from skin biopsy.
Lipids/Trace Metals
SAG
5 days
7635