Chomchai, s

Document 7: Argyria

May 3, 2004

Robert C. Holladay, MS

Toxicity from silver ingestion is not a concern, because individuals must ingest horrendous amounts of silver to die from overdose. An individual would exhibit symptoms of argyria well in advance of ingesting enough silver to cause toxicity. Argyria is a condition in which excess amounts of silver are deposited on the outer layers of skin causing it to turn light blue or gray. It is not dangerous, but it is cosmetically undesirable.

A review of the medical literature relating to argyria was conducted by a team of scientists from the United States Environmental Protection Agency for the purpose of including silver in the Integrated Risk Information System. “Health assessment information on a chemical substance is included in IRIS only after a comprehensive review of chronic toxicity data by U.S. EPA health scientists from several Program Offices and the Office of Research and Development. The summaries presented in sections 1 and 2 represent a consensus reached in the review process” (1). The fact that scientists are taken from several different parts of the EPA and are forced to review the relevant literature and come to a consensus eliminates much of the risk of bias or error in the IRIS report. Because of this, the information contained in the IRIS is more reliable than an individual study.

The IRIS gives an oral Reference Dose (RfD) for silver, which is “an estimate of a daily exposure to the human population that is likely to be without an appreciable risk of deleterious effects during a lifetime” (1). The RfD is expressed in units of mg/kg-day, which relates to an individual’s bodyweight. The RfD established for silver is .005mg/kg-day (2). This means an individual that weighs 70 kilograms(154 pounds) could safely ingest .350 milligrams of silver per day for a lifetime. An individual weighing 77 pounds could safely ingest .175 miligrams of silver per day (1).

As previously mentioned, the IRIS was created after an extensive review of the relevant literature by EPA scientists. They based the RfD on the most thorough and reliable study available in which 70 cases of argyria were reported by Gaul and Staud. The data found in this study was in agreement with other reliable data the scientists were able to access. (including Document 6, reference 10) One segment of Gaul and Straud’s report which the EPA scientists considered to be of exceptional reliability was the case of 12 individuals who were given i.v. injections of silver arsphenamine. The patients were in the advanced stages of syphilis and were of compromised health. In addition, many of them had received enormous injections of other heavy metals. The most sensitive of these individuals developed argyria after receiving an i.v. dose of 1 gram of silver. It is not known if he had previously been exposed to silver. Others did not develop the same condition “until levels five times higher were administered”. The EPA scientists were conservative, and decided to base the RfD on the assumption that 1 gram of silver administered i.v. will cause argyria. A safety factor of three was applied, which means the actual RfD is based on the assumption that 1/3 gram of silver administered i.v. will cause argyria. It was estimated by the scientists that one must ingest 25 grams of silver to equal the effect of receiving 1 gram intravenously. Hence the RfD became .005mg per kilogram of bodyweight per day. A 154 pound individual could ingest 350 micrograms of silver per day for 70 years (25500 days), which would be a total of 8.9 grams of silver. 8.9 grams divided by 25=.35 grams of silver (1)(approximately equal to 1/3 gram of silver administered i.v.). The RfD is extremely conservative.

One teaspoon of 10 ppm colloidal silver contains about 50 micrograms of silver.

(1) U.S. Environmental Protection Agency. 1996. Integrated risk information system, silver.

(2) U.S. Environmental Protection Agency. 2001. Quickveiw, silver.

The EPA and website can be found by typing “EPA” into any search engine. The specific documents can be found by entering the title in the search box which is available on the EPA website.

(3) Chomchai, S. and S.Y. Kim. 2000. Argyria secondary to chronic ingestion of colloidal silver. Journal of Toxicology. 38: 552.

A 35-year old woman contracted argyria after orally ingesting 66mg of silver from a colloidal silver protein solution over a period of a year.

Comment: There is no mention of anyone testing her colloidal silver solution for silver content. Since this claim is extremely inconsistent with the existing medical literature relating to argyria, the colloidal silver solution she was ingesting probably had a much higher silver content than was reported.

(4) Gaby, Alan R. 2001. Potential hazard of colloidal silver. Townsend Letter for Doctors and Patients. February: 160.

An individual who contracted argyria had been ingesting 3 teaspoons of 200 ppm colloidal silver daily for the past 3 years.

Comment: The silver content of his colloidal silver solution was not tested and therefore this information is not reliable.

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