Thursday, September 30, 2010

A Simple Case of Silver Poisoning

by Deborah Blum

In two earlier posts, I wrote about the possible copper poisoning of the great British poet and artist William Blake and the apparent gold poisoning of the powerful mistress of a French king, Diane de Poitier.

The very simple lesson in both stories seems to be that regular metal exposure will kill you. And certainly there are many other examples to support this. The metal lead is a notorious neurotoxin, and recent news stories link it directly to the poisoning of some 18,000 people in mining regions of Nigeria. The metal mercury is equally dangerous, enough so that all of us are warned against eating too much seafood--especially long-lived fish like salmon and tuna--because of environmental mercury contamination in the oceans.

One could argue, of course, that this is too simple a lesson. As always in toxicology, the dose makes the poison. Health experts today actually recommend regular metal intake, at least in very tiny amounts, for strengthening everything from bones to immune function. My daily multivitamin, for instance, contains 8 milligrams of iron and .5 mg of copper. And also trace amounts of zinc, nickel, manganese, molybdenum and chromium. I occasionally worry that over a lifetime I'll have swallowed a tin can's worth of metal. And some health experts worry that long time, metals like copper and iron in vitamins may bioaccumulate (build up in tissues).

But you might ask, are all metals health risks in larger quantities? An interesting--but definitely peculiar--exception turns out to be silver, one of the precious metals. The following is a story, concerning that point, from my recent book, The Poisoner's Handbook:
In the chilly January of 1924, scientists at the New York City Medical Examiner's office got a chance at a true oddball case, the death of the Famous Blue Man. The man had spent most of his life as one of the human curiosities exhibited at Barnum and Bailey’s, the Greatest Circus on Earth, as it traveled around the country. The Blue Man had recently died at Bellevue; the pathologists said his body was one of the strangest they’d seen stretched on a marble table in the morgue.

The famed human oddity was 68 years old when he checked himself into the hospital, short of breath and complaining that when he lay flat, he couldn’t breathe at all. As his hospital records noted, he was a tall, thin man, with glistening white hair and an equally glossy white mustache. His skin was so deep a blue to appear black at a distance. His lips were blue; his tongue was blue. The scleras--what would usually be called the whites of the eyes--were also blue.
This wasn’t the exhausted bluish patchiness of cyanide poisoning though. The skin was smoothly colored with an almost lustrous look. It was that overall effect of polishing that led the doctors to a diagnosis--the Blue Man was suffering from a disease called argyria (from the Greek word argyros meaning silver). The condition was known to deposit silver through the body, staining the tissues to a deeply polished blue-gray.

The Bellevue doctors suspected that the Blue Man, a former British army officer, had achieved his later fame by dosing himself with silver nitrate. This was a salt made by dissolving silver into nitric acid and evaporating the solution, leaving behind a glossy powder, which could be mixed for other uses. Silver nitrate was easily available;  it was used in photographic processing, by dentists to treat ulcers in the mouth, and blended into drops that went into the eyes of newborn babies to prevent infections.

Their patient firmly denied any silver exposure, denied any self-medication at all. As he’d told his circus admirers, he was a freak of nature, he insisted, and blue at birth. But when he died that fall--from rapidly worsening pneumonia--they decided to take a thorough look at his story. The resulting autopsy showed that he was blue-silver on the inside too, the membranes smooth and glistening, the muscle tissue a dull, reddish brown with a faint silver tint, the spleen colored a bluish red, the liver bluish gray. Even the brain shone silver, its familiar curves and coils slightly reflective in the pale light of the morgue.

Still, how much metal did his body contain? To find out, city toxicologist Alexander Gettler made an acid solution of the organs and cooked it dry, creating a gray ash. He flushed hot water, ammonia and nitric acid through the ashes, washing the silver out of them. He then measured the silver from each organ, totaling up the results to calculate the whole body content. Gettler’s conservative estimate was that the Blue Man’s body contained a good three-and-a-half ounces of solid silver. About half the metal was in the muscle tissue, another fourth in the bones, and the rest mostly concentrated in the liver, kidneys, heart and brain.

But the silver hadn’t killed the Blue Man. He had died of the pneumonia; the only effect that silver doses seemed to have had was to turn him that remarkable deep indigo color. “Among the heavy metals which may become deposited in the human body in relatively large amounts,” Gettler wrote in his report on the case, “silver is of slight and perhaps least toxicity.”

Of course, the toxicology lab was now in possession of a nice quantity of pure silver. His co-workers took the gleaming pellets acquired from the Blue Man’s body, melted them down and shaped them into a bullet. Just in case, his friends assured Gettler, he ever had to analyze a vampire. He carefully placed the bullet on his desk. Just in case, he replied.

It's a good story--or so I think--but it also makes a case that, among the metals, silver is relatively neutral in effect (as long as one doesn't care, of course, about turning blue or accumulating internal silver deposits). It also led me to consider the possibility that with some effort, one could become the amazing precious metal human, storing wealthyinternally ,so to speak, in which case my choice would be platinum.

But as it turns out, becoming the Famous Platinum Woman,would work only if I was willing to insert the word "Dead" into that description. Platinum turns out not only to be wonderfully valuable but wonderfully poisonous. So, between you and me as concerns metal exposure, I'm hoping to limit myself to those multivitamins.

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