Silver is noble metal of Ib group of Periodic table of the elements. Silver can find in nature in native conditions. It belongs to transition metals. Silver has affinity to sulphur, tellurium, selenium and oxygen. In nature silver occurs as indissoluble and unmovable oxides, sulphides and other salts. Average concentration in soil is 0,1 ppm, and in Earth crust is 0,07-0,08 ppm. Chlorides, sulphides, phosphates and arsenates are indissoluble; bur silver-sulphate is partly soluble, until silver-nitrate is very soluble. Silver is using for gem, alloys, photography, battery, mirrors, electronics, galvanisation and like agency for disinfection.
Origin in water
Silver are sometimes in underground, surface or drinking waters in concentration bigger then 5 mg/1.
High concentration of colloidal silver can be fatal for people and animals even with single dose. Just little percent of silver absorbs.
There are not any studies which can confirm mutagen or cancerous effect of silver. Low silver concentration in fresh water, are not relevant for human health. From the other side, silver salts can be useful for bacterial quality of drinking water
Chronic effects of low silver concentration can cause argiria- skin decolour.
Maximal allowable concentrations
When the silver salts use for keeping of bacterial quality of drinking water, can tolerate silver concentration to 0,1 mg/1, without risk for health.