What is Silver Toxicity?
Silver is a soft metal that our bodies don’t need to function. It’s special because it’s the best at conducting electricity and heat, and reflecting light, out of all metals. These qualities make silver useful in many different areas of our lives. People have been exposed to silver for hundreds of years, even back in ancient times. Today, exposure to silver can come from industries, workplaces, medicines, and health or nutritional supplements. If a person is exposed to silver too much or for a long time, they can develop silver toxicity. The main health issue from this is a permanent change in skin color to blue or slate-gray because of silver deposits, and this condition is called argyria.
Silver levels in human tissues are usually low. However, if a person is overly exposed to silver, it can build up in various places in the body such as the skin, liver, kidneys, the lining of body parts that make mucus, corneas (the clear front layer of the eye), gingiva (gums), spleen (an organ that filters blood), and nails.
What Causes Silver Toxicity?
You can come into contact with silver in several ways, such as by eating, breathing, or touching it.
Many products contain silver compounds. These include things like batteries, medicines, mirrors, jewelry, electronic parts, dental fillings, money, and even acupuncture needles. Silver is also used in making photographic plates, as a catalyst in chemical reactions, for lubrication, in weather modification, window coatings, preserving flowers, electronics, sanitation supplies, and more.
Certain jobs expose people to small silver particles. These jobs include silversmiths, miners, welders, jewelers, or those who work in the photography industry. Safety guidelines vary, but many European countries suggest an 8-hour average of 0.1 mg/m³ for silver dust. The US also has a limit of 0.01 mg/m³.
Silver also has medical uses due to its ability to kill microorganisms. Silver nitrate is used for cauterizing wounds, and silver sulfadiazine for treating burns. Silver also coats medical device catheters to prevent infections. This is because silver ions can damage bacterial cells.
Consumers also use silver for its antimicrobial effects. Colloidal silver, a liquid supplement containing small silver particles, is used in alternative and homeopathic medicine. Silver is also used in personal care products like bandages, shower gels, and deodorants. However, the product must not claim to treat or prevent diseases.
Exposure to silver can have side effects. Argyria, a condition that turns your skin a bluish-gray color, and argyrosis, a similar condition for the eyes, are linked to silver. These effects are most noticeable in areas exposed to sunlight and often occur with long-term exposure to silver. This could be through the skin or body contact, breathing in silver in workplaces, eating silver, or using colloidal silver or silver-based medicines, silver solder, and even smoking deterrents. The toxicity of silver nanoparticles is thought to work the same way as their antimicrobial effects—by releasing a lot of silver ions which can cause damage.
Risk Factors and Frequency for Silver Toxicity
Historically, silver has been used for its antimicrobial properties, dating back to ancient civilizations. In the earlier part of the 20th century, the rise of antibiotics led to silver being less commonly used. There were still rare cases of a condition called argyria, usually linked to consuming things called colloidal silver that people used for alternative and homeopathic medicine, which you can find easily in places like grocery stores, pharmacies, or online. An increase in these types of health trends has led to a resurgence in argyria cases.
In 1994, an act called the Dietary Supplement Health and Education Act said that silver could be sold as a supplement, but could not be claimed to treat or prevent any diseases. Then, in 1999, the United States Food and Drug Administration stated that products labelled as over-the-counter drugs containing any form of colloidal silver or silver salts for internal or external use were not generally recognized as safe and effective and were misbranded.
Recently, silver in ionic and nanoparticulate form has seen more use in medical and commercial products. Colloidal silver is made up of small silver particles and ions, smaller than 100 nm (nanoparticles) and less than 1000 nm (microparticles) in an aqueous suspension. Most of these products claim to have 10 to 30 mg/L of silver. The World Health Organization states a Reference Dose of 6.5 mcg/kg body weight/day for exposure to silver – this is based on when people develop argyria, the silver-related condition mentioned earlier.
The issue with the mass production and sale of colloidal silver is that it has potential drawbacks like inconsistent production standards and unexpected side effects. Although regulatory bodies like the Food and Drug Administration and the European Commission don’t stop the selling of colloidal silver, they do prohibit unfounded health claims.
Signs and Symptoms of Silver Toxicity
Silver toxicity or argyria is a condition that occurs due to excessive exposure to silver. It’s usually detected in people who’ve either been exposed to silver in their workplace, consumed certain medicines, supplements or used consumer products that contain silver. The time it takes to see signs of this condition can vary greatly, ranging from a few days to several years. Regardless of the amount of time that has passed since the initial exposure, the diagnosis can still be made because the skin discoloration caused by silver is permanent.
Signs of silver toxicity include skin turning from blue to slate-gray due to silver deposits. Typically, it starts with the gums turning gray, followed by the skin in sun-exposed areas. Later, it may affect the nails, tissues around the eyes, interior surfaces of the lips, cheeks, and other areas in the mouth. Autopsy might reveal bluish internal organs. Sunlight can cause the skin in the affected areas to turn an even darker shade as it reacts with the silver deposits and stimulates increased pigment production in skin cells. This increased pigmentation can also be noticed on the skin, nails, eyes, and mucosal surfaces.
- Gums turning gray
- Hyperpigmentation in sun-exposed areas
- Nails, and the moist lining of the mouth and eyes turning darker
- Internal organs appearing blue during autopsy
- Even darker skin discoloration due to the reaction of sunlight with silver deposits
Testing for Silver Toxicity
The normal amount of silver in the blood is usually less than 1 microgram per liter. Silver can be tested in the blood, feces, and urine. However, it’s tricky to determine how much silver in the body leads to a condition called argyria, where the skin turns a bluish-gray color.
So, doctors mostly diagnose argyria based on your medical history and a physical examination. There is no set level of silver in the blood that indicates early argyria. Some studies suggest that argyria can occur when the total amount of silver ingested weighs as little as 70 milligrams per kilogram of the person’s body weight.
If doctors suspect argyria, they might take a small sample of your skin (a biopsy) and look at it under a microscope. The most accurate way to diagnose it is by a method called energy-dispersive x-ray spectroscopy. This technique can clearly identify the chemical elements, like silver, in tissue samples by analyzing the energy they give off.
Treatment Options for Silver Toxicity
There isn’t a specific cure for silver poisoning, and the treatment mostly involves trying to relieve symptoms and keep the person as comfortable as possible. The treatment for argyria, a condition where your skin turns blue-gray from silver buildup, hasn’t been very successful overall and is often considered to be long-lasting, with the discoloration being somewhat permanent.
A major part of managing this condition is to stop things that could make it worse. For example, you should avoid further exposure to silver, limit your exposure to the sun, and use sunblock whenever you are in sunlight. There have been attempts at trying to reverse argyria, including hydroquinone (a skin-bleaching agent), rough exfoliation of the skin, or using a medication called D-penicillamine, but these have not shown notable results.
However, some recent reports show a bit of promise. There have been attempts to use certain types of laser therapy, the same type used to remove some tattoos, to try and improve the discoloration caused by argyria. This involves using machines called Q-switched frequency neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers and 755-nm alexandrite lasers. These have sometimes shown some success in restoring skin color, even up to a year after treatment. It’s important to know, though, that argyria can come back, as there have been cases where it reappeared 11 months after treatment. Also, the laser treatment can be quite painful, and may need local or even general anesthesia (being put to sleep for the procedure).
What else can Silver Toxicity be?
When a doctor is trying to find out if a patient has silver toxicity, they should also consider these other diseases or conditions, because they can have similar symptoms:
- Addison disease
- Usage of Amiodarone
- Chrysiasis
- Cyanosis
- Usage of Dapsone
- Hemochromatosis
- Melanoma
- Methemoglobinemia
- Usage of Minocycline
- Ochronosis
- Usage of Phenothiazine
- Polycythemia
- Porphyria
- Wilson disease
What to expect with Silver Toxicity
Argyria is a condition that primarily causes permanent changes and doesn’t get better even after you’re no longer exposed to what caused it. Although argyria doesn’t pose a direct threat to your life, it does lead to the systemic absorption and distribution of a metal called silver in your body. This results in an unwanted change in looks, as the affected areas of your skin will be permanently discolored.
The areas with the highest levels of silver in your body due to this condition are your skin, liver, kidneys, the cornea which is a part of your eye, and your gums. We know this from post-mortem examination reports of people who were treated with silver for treating burns.
Possible Complications When Diagnosed with Silver Toxicity
Overuse of silver can lead to various whole-body or systemic complications. Research mainly from animal studies and case reports has noted these issues. These complications can affect several body systems like the cardiovascular, dermatological, hematological, liver, gastrointestinal, neurological, and kidney functions.
In terms of skin effects, “Argyria,” a condition that turns skin a bluish-gray color, is the most famous issue tied to too much silver. There are three main subtypes, including widespread, local, and eye-related or “argyrosis.” Widespread argyria can discolor your whole skin a gray-blue or metallic shade, particularly where the sun hits. Local argyria, on the other hand, occurs only in the area where silver has been absorbed by your sweat glands or through cuts on your skin. This type is usually seen after long-term contact with silver-infused items like creams or solutions. Argyrosis can happen in your eyes as part of either the widespread or local forms of skin changes. It brings about dark spots with a green or brown hue in parts of your eyes.
Effects on the nervous system may include silver building up in brain and spinal cord cells and possibly disrupting their functions. In animal studies, the overuse of silver salts has been potentially linked to such issues. An example is a woman who used silver products to treat a mouth condition she had for nine years. Continuous use of these remedies resulted in silver accumulating in her mouth tissues, causing her to experience increased dizziness, weakness, a loss of smell, issues with coordination, and reduced skin sensation.
Kidney complications related to overuse of silver have included protein in the urine and damage to part of the kidneys. Other known issues have involved the blood, where silver use was seen to reduce the production of white blood cells that help fight infection in the body. Excessive silver use can also negatively impact the liver, heart, and lungs. Although rare, these complications could be severe; for example, a person who overused silver products died from heart failure after silver deposits were found in his blood vessels.
Lastly, if silver is inhaled, it can irritate your airways and cause lung inflammation.
In terms of dangerous doses, intravenous intake of silver can be lethal at around 50mg, causing destruction in bone marrow, kidneys, and liver, bleeding, and fluid in the lungs. However, some reports suggest an average lethal dose of 10g but survival after ingestion of 30g. A lifetime intake of 10g can generally be considered safe. However, there have been reports of people dying due to silver, including a case where a large dose was administered into the womb following an abortion procedure.
Preventing Silver Toxicity
It’s essential for patients to understand the potential risks and harmful effects associated with silver toxicity, which includes a condition called argyria. Argyria is a skin condition where the skin turns a blue-gray color, and it can be irreversible. It’s also important to know that many colloidal silver products are sold with health benefits claims that are not based on scientific evidence, because of different government regulations.
Accessing psychological support and counseling can be helpful, as this provides a space to talk about any concerns, fears, or anxieties related to the condition. These sessions are also a good opportunity to learn about the available treatment methods for silver toxicity.
