The Science of Argyria
The excuses venders of colloidal silver give to clear themselves of responsibility when their customers turn gray or blue are completely silly, and the reason is simple. Argyria has only one cause, consuming silver... and it doesn’t matter what form the silver is in, or how small or large the dose. All that matters is that silver is consumed long enough.
Most of the silver that a person eats gets passed right through their bodies and out with the excrement; but a small percentage — usually about ten percent — is absorbed by the gastrointestinal tract in the mouth and nasal passages or in the lower intestines (depending on the form of silver ingested) and enters into the bloodstream. The absorbed silver travels in the bloodstream either as silver salts or combined with an available protein, and only leaves the blood when it is deposited along with nutrients and oxygen into the tissues of the body. Organs that receive a greater amount of blood also receive a greater amount of the silver. The silver forms small dark granules in the tissues of the organs, and it is these granules that lead to the discoloration of skin; in fact, a skin biopsy showing these granules is the standard test for argyria.
Skin is the largest organ in the human body and receives a huge amount of blood, which is why the silver can end up there. It has long been noted — as early as 1817 — that the discoloration of argyria seems to begin in and stay strongest in areas of the body that are exposed to the sun... the head, back of the neck, and arms are typically darker in tone than the remainder of the body, and many people who stop consuming silver when the argyria starts have these portions of their body discolored, but normal skin tone on the rest of their bodies. The granules formed by the silver tend to accumulate around the eccrine glands, which are the sweat glands that empty directly to the surface of the skin, below the epidermis (outer layer of skin) where melanin resides and determines normal human skin tone. The granules are never found in the epidermis. This may be because the tissues of the epidermis are not directly supplied with nutrients and oxygen by blood vessels, instead allowing these to pass on their own through the tissues by molecular diffusion from areas of high concentration (the lower dermis) to areas of low concentration (the epidermis). So the silver only goes as far as the bloodstream can carry it, but also seems to follow the flow to the sweat glands.
Because the deposits depend on blood flow, people with argyria not only have discolored skin, but they also have discolored internal organs due to further deposits of silver granules: the liver, spleen, and adrenal glands can all be effected. The deposits also build up in capillary walls, joints, nerves, and even in the brain. Luckily, at low dosages the body appears to pass more than enough silver intake to prevent health problems past the change in colors; but eating a single large dose of silver — as in multiple grams — is likely to kill you. In fact, argyria requires regular doses of silver to occur; single, large, un-repeated doses separated by years can’t cause it, but daily small doses can bring the condition on in as little as ten months... though three years seems to be more the average time frame it takes for the discoloration to clearly appear.
When large doses of silver are taken in, the deposits start to impinge on the central nervous system, causing loss of voluntary movement or weakness and rigidity of legs, and can effect the muscle tissue and nervous tissue of the heart... which is probably why Captain Fred Walters died of heart failure in 1923 after consuming silver for most of his life. Consuming large doses of colloidal silver in particular can result in a coma, a buildup of fluid in the cavity around the lungs, and cause red blood cells to break apart (hemolysis). It is also toxic to bone marrow — where red blood cells are manufactured — and can impair the bone marrow’s ability to produce the white blood cells needed to defend against bacteria and viruses (agranulocytosis). This is similar to the effects of consuming any corrosive solution; and in a large enough concentration, it can be lethal. This appears to be because colloidal silver has a higher rate of absorption into the gastrointestinal tract, due to the submicroscopic size of the silver particles being consumed. But most consumers of silver will never take a dose large enough to cause the more severe health problems; and for most, having gray or blue skin is severe enough a condition.
The real problem with argyria is that there is no known threshold of how much silver consumed will cause the discoloration. Some people have higher than usual exposure to environmental sources of silver, and therefore may need less intake to become argyric. In addition, some people appear to be more vulnerable to the condition, and to generally need less silver intake to cause it... this may be due to differences in the mucous membranes of the gastrointestinal tract — the mucous membranes are what traps most of the silver consumed and forces it to be passed in the excrement. Weaker mucous membranes could lead to a higher absorption of silver. There may also be chemical differences in the blood, resulting in a higher rate of deposit compared to the silver being filtered out by the kidneys. In short, different people appear to need differing amounts of silver to become argyric.
Consuming small amounts of silver on a regular basis will slowly deposit silver granules in the tissues of the body, and some people will do this faster than others... and when there is enough deposited, the color caused by the deposits will slowly become more and more evident. The color, also, seems to be different for each person; and whether they are slate gray, shiny silver, blue, or purple may also depend on chemical differences within the victim’s body. Once the discoloration appears, the color never changes except to become a more intense version of the same color if consumption of silver continues. Claims have also been made that only large silver particles cause argyria, and that silver prepared as small particles won’t; but the smaller particle size likely makes the silver easier for the gastrointestinal system to absorb.
So, once again, nothing in the preparation or amount of the silver really matters as much as the fact that silver is being consumed. All a larger dose will do in most cases is speed up the inevitable change... and the true believers in colloidal silver who insist that consuming it in small enough amounts avoids becoming argyric are just gambling with how much time and silver is needed to prove them wrong.
So the saddest part of this whole situation is that the fact that eating silver will permanently change your skin color has been a sort of open secret for at least 170 years, known to many individual scientists and doctors, but never clearly stated to the public or scientific community at large... and that this situation is being used by unscrupulous or misguided people to sell a product that poses a health threat to those that use it.
Hopefully, you will think twice before trying silver as a cure-all.