|Clear Springs Press||
Colloidal Silver Toxicity - How much is harmful?
(This is a chapter from the book Colloidal Silver: Medical Uses, Toxicology and Manufacture)
Can Colloidal Silver harm you? Almost anything can be harmful if used in excess. This includes commonly used drugs and even common foods. Potatoes, tomatoes, wheat, mushrooms, and many other common foods contain toxins and/or carcinogens or even mostly harmless substances which can be harmful to susceptible individuals. They don't usually harm us because we limit their consumption to levels that our body can adapt to, and metabolize.
The bottom line is that small doses of silver seem harmless for most people while large doses taken in great excess can be toxic. So the question is: What constitutes a small safe amount and what constitutes a large potentially harmful amount?
Unfortunately, there is no definitive answer to that question. There is, however, some information available that can serve as points of reference from which an "estimate" can be made.
Much of the toxicological data is derived from data on silver salts and silver proteins with much higher silver content than current electrocolloidal products. It is also true that colloidal silver, silver salts, and silver proteins cannot be assumed to produce the same results or have the same toxicities.
In addition to argyria, the intake of very large doses (far in excess of the amount that causes discoloration of the skin) of silver can cause neurological damage, organ damage, and arteriosclerosis.
In one research project, dogs died from injections of a type of protein bound silver in dosages ranging from 500 mg to 1.9 grams of silver depending on the dosage and frequency of administration. (46) This was equivalent in silver content to giving a 150 pound adult between 150 and 570 liters of 10 PPM colloidal silver, or between 75 and 285 liters of 20 PPM colloidal silver, or between 50 and 190 liters of 30 PPM colloidal silver. The 10 gram estimated lethal dose for humans from Goodman and Gillman (56) is equivalent in silver content to 1000 liters of 10 PPM colloidal silver.
In this study (46), the authors were attempting to cause anemia in dogs for experimental purposes rather than test the effect or safety of colloidal silver. They injected Collargol, which contains approximately 87% silver with the remainder being albuminous proteins.
In one test, they injected 500 mg of Collargol into a 23 kg dog. The dog died 12 hours later. They further noted that doses of 1.3 to 1.5 grams of Collargol are tolerated (before death occurs) if divided and given at the proper intervals over a period of 3 to 7 days. Single doses of 200 to 300 mg were well tolerated. Death usually followed a single large dose.
Upon necropsy, the following pathological changes were noted:
(1) There was moderate congestion and marked edema of the lungs.
(2) The reticuloendothelial cells of the liver and spleen contained coarse silver deposits. So did lymph nodes, bone marrow, and to a lesser degree, the kidneys.
(3) The bone marrow showed slight to marked hyperplasia with no death to the parent cells and contained many mononuclear cells filled with brown (silver) pigment.
(4) The hematocrit dropped 10 to 14 percent.
(5) There was a slimy exudate from the nose.
(6) Those overdosed over a longer time period became emaciated.
The administration of smaller doses, 20 to 50 mg over intervals resulted in mild leukocytosis and an increase in hematocrit.
The authors reference another article in which a human died two hours after receiving an intravenous injection of 50 mg Collargol. An autopsy revealed changes nearly identical to those described for the dogs.
More recently, Motohashi performed an experiment in which Collargum was injected into rabbits. After the injection, he observed that the hemophages began "ingesting the animal's own erythrocytes abnormally." He determined that the minimum dose of injected Collargum into rabbits which caused increased hemophage activity was 1 cc of a 1:10000 dillution per kilogram of weight. (123)
In another case (47), an individual ingested an estimated 124 grams of silver nitrate over a period of 9 years. She developed argyria and an assortment of neurological symptoms as well. The authors note that the silver tended to complex with sulfur in the form of Ag2S. A moderate presence of silver-sulfur granules were seen in the perineural tissue, in the peripheral nerves and along the elastic fibers, and to a lesser extent along the collagenous fibers, and in macrophages. These deposits were noted to have an affinity for basal membranes. The neurological manifestations included taste and smell disorders, vertigo, and hyeresthesia. This report is often used by critics to attribute neurological disorders to colloidal silver consumption. For comparisons to be meaningful, differences in dosage regimens must be accounted for.
It may be helpful to put this in perspective with the quantity of silver that is consumed in food and drinking water from natural sources. The EPA publishes a reference dose (RFD) for silver which is an estimate of daily exposure to the entire population that is unlikely to be associated with a significant risk of adverse effects over a lifetime. The current RFD for oral silver exposure is 5 micrograms/kg/day with a critical dose estimated at 14 micrograms/kg/day. The maximum contaminant level proposed by the EPA for silver in the drinking water is less than 0.1 mg/L (less than 0.1 PPM).
Based on this RFD, a 150 pound adult should not exceed 350 micrograms/day. If the silver in drinking water meets EPA standards, an average person drinking 2 liters per day will consume less than 200 micrograms of silver. In addition the daily diet may contain about 90 micrograms of silver. (63) 350 micrograms of silver is equivalent to 70 milliliters (14 tsp) of 5 PPM colloidal silver. This is the amount that the EPA standards permit an individual to consume from natural sources.
Some researchers have suggested that a deficiency of selenium and vitamin E may increase the susceptibility to systemic silver toxicity. It was hypothesized that silver toxicity, as manifested by liver necrosis in laboratory rats, was due to silver induced inhibition of the synthesis of the seleno-enzyme glutathione peroxidase. Bunyan, et. al., showed that rats supplemented with selenium or vitamin E tolerated a silver exposure of as high as 140 mcg/kg/day. (63)
It is also necessary to remember that some individuals have allergies to specific metals. Nickel, copper, silver, and other metals have been known to cause allergic reactions. Be certain that you are not allergic to silver before taking colloidal silver.
Back to the Table of Contents