Silver compounds may be absorbed through inhalation, but there are no quantitative human data on the extent of this phenomenon. Silver salts may be absorbed by up to 10-20% after ingestion. The highest concentrations of silver are usually found in the liver and spleen, and to some extent in the muscles, skin, and brain after ingestion. The biological half-time for silver ranges from a few days for animals up to approximately 50 days for the human liver; it is possible that skin deposits have an even longer half-time, but there are no quantitative data on this for man. Silver binds to high-molecular-weight proteins and metallothionein in tissue cytosol fractions. Excretion of silver from the body is primarily biliary. Water-soluble silver compounds such as the nitrate have a local corrosive effect and may cause fatal poisoning if swallowed accidentally. Chronic exposure of humans leads to argyria, a clinical entity characterized by grey-blue pigmentation of the skin and other body viscera. Repeated exposure of animals to silver may produce anemia, cardiac enlargement, growth retardation, and degenerative changes in the liver.