Silver, a naturally occurring element, exists widely in the Earth’s crust and environment, used in various industries from electronics to jewelry. Many people wonder about its interaction with the human body. Understanding how this element exists within us and how the body handles it provides valuable insight.
Normal Amounts in the Body
The human body contains silver, though it is not considered an essential element for biological processes and fulfills no known physiological role. Most people are exposed to very low levels of silver daily, primarily through food and drinking water. The typical daily intake for humans is estimated to be between 70 and 88 micrograms, with about half of this amount coming from dietary sources. Trace amounts of silver are distributed throughout the body and can accumulate in various organs, including the liver, skin, brain, endocrine glands, and kidneys.
Common Ways Silver Enters the Body
Silver can enter the human system through several common pathways. Ingestion is a primary route, with exposure occurring through food and drinking water, where public supplies can contain up to 80 micrograms of silver per liter. Inhalation represents another pathway, particularly in occupational settings involving silver dust or compounds. Silver nanoparticles can also be inhaled and distributed throughout the body.
Dermal contact, though generally less significant than ingestion or inhalation, can introduce silver through certain medicines, burn creams, or consumer products. Silver is also present in some consumer and medical products, including certain cosmetics, medical devices like wound care products, catheters, and dental amalgams, as well as traditional remedies and dietary supplements such as colloidal silver.
Impact of High Silver Levels
When silver accumulates in the body beyond normal trace amounts, it can lead to a condition known as argyria, characterized by a distinctive blue-gray discoloration of the skin. A similar effect in the eyes is called argyrosis. Argyria is generally considered a permanent condition, with the skin color change being irreversible. Despite the cosmetic change, argyria is typically not considered life-threatening. However, it can significantly impact an individual’s appearance and quality of life.
Other, rarer toxic effects can occur with very high levels or prolonged exposure to soluble silver compounds, rather than from normal dietary intake. These severe cases may involve liver and kidney damage, irritation of the eyes, skin, respiratory tract, and intestinal tract. Changes in blood cells and, less commonly, neurological effects have also been reported.
How the Body Processes Silver
Once silver enters the body, a portion is absorbed into the bloodstream. An estimated absorption rate for ingested silver is up to 10%. Absorbed silver forms complexes with proteins, which helps transport it throughout the body. Silver distributes to various tissues and organs, including the skin, liver, kidneys, spleen, lungs, and brain. Research indicates silver can cross both the blood-brain barrier and the placental barrier.
The body processes and eliminates silver at varying rates. The primary excretion route for ingested or inhaled silver is through bile and feces, with most leaving the body within about a week. A smaller amount is excreted via urine. Minor elimination routes include sweat, saliva, and breast milk. While some silver can accumulate in tissues over time, especially with chronic exposure, the body continuously works to remove it; for instance, its biological half-life in the liver ranges from several to 50 days.