Antimony!

antimonyPicture this. You swallow a little pill, wait until it irritates your intestines enough to expel its contents and then hunt through the expelled excrement to retrieve the pill. Why? So you can use it next time to get rid of the bad humours in your body that are making you sick. How can a pill survive passage through the digestive tract? It can, if it is made of metal, in this case, antimony. Now, don’t go asking the pharmacist for antimony pills. The scenario just described isn’t current, it was plucked out of the Middle Ages when the cure for disease was to expel “bad humours” from the body. Actually, that was not unlike the current craze of expelling unnamed toxins from the body with a variety of “cleanses,” many of which have a laxative effect.

Hopefully nobody today would be silly enough to use antimony or its compounds, because here we are talking about real toxicity. Of course they didn’t realize that in the Middle Ages; all they knew was that antimony was pretty good at evacuating the body. And not only through the rear portals. One method involved drinking wine that had been left standing overnight in a cup made of antimony. This resulted in the antimony reacting with tartaric acid in the wine to form antimony tartrate, a compound that induces vomiting. The idea of purging the body to treat illness persisted into the late stages of the 18th century. When Mozart came down with a mysterious illness, he was treated with “tartar emetic,” as antimony tartrate was commonly called. What ailment he suffered from isn’t clear, but he died within two weeks. His symptoms of intense vomiting, fever, swollen abdomen and swollen limbs are consistent with antimony poisoning. Of course, we cannot prove that antimony was responsible for Mozart’s death, he also suffered from rheumatic fever since childhood, a condition that may have led to his demise at a young age.

Mozart had always been sickly and it is well known that he had been often treated with antimony compounds by his physicians and that he even dosed himself when he didn’t feel well. It is interesting that Mozart actually believed he was being poisoned, but not by himself. He thought his musical rival Antonio Salieri was trying to do him in. Although the famous movie “Amadeus” alludes to this possibility, historical facts do not corroborate the poisoning story. Contrary to the portrayal, Salieri did not confess at the end of his life to having tried to kill Mozart.

Back in the 1990s a volatile compound of antimony known as stibine (SbH3) was accused of being responsible for crib death. The theory was that it was produced from antimony oxide added as a flame retardant to polyvinylchloride sheets. A fungus found in mattresses supposedly made this conversion possible, at least under laboratory conditions. The theory has now been dismissed because neither the fungus, nor levels of antimony in babies’ blood could be correlated with crib death.

More recently Greenpeace created a stir with a booklet entitled “A Little Story About The Monsters In Your Closet.” What sort of “monsters?” The subtitle brings them out of the closet: “Study finds hazardous chemicals in children’s clothing.” Yup, the monsters are chemicals. One that the Greenpeace study detected was antimony trioxide, present in all fabrics that have polyester as a component. No great surprise here since antimony trioxide is used as a catalyst in the production of polyester as well as a flame retardant. And it is true that antimony trioxide can be described as presenting a hazard. But hazard is not the same as risk.

Hazard is the innate potential of a substance to cause harm without taking into account extent or type of exposure. Inhalation of antimony compounds in an occupational setting can be a problem, and it is correct that antimony trioxide has been classified as “suspected of causing cancer via inhalation.” But this is not relevant for the trace amounts found in fabrics. Here the issue would be migration out of the fabric and subsequent absorption. This has been extensively investigated and the amounts that are encountered are well below the established migration limits. The same applies to the trace amounts that leach out of the polyester bottles that are widely used for water and other beverages. Concentrations are less than the 5 parts per billion safety limit.

Antimony does not occur in nature in its metallic form, so where did Middle Age physicians get it? Like most metals, antimony has to be smelted from its ore, in this case antimony sulfide, also known as stibnite, a substance that has been known for thousands of years. Jezebel, the Biblical temptress is said to have used it to darken her eyebrows and stibnite was the main ingredient in “kohl” used by ancient Egyptian women in a type of mascara. Exactly who figured out that heating antimony sulfide converts it to antimony oxide, which yields metallic antimony when fired with carbon, is unknown, but if you visit the Louvre, you can see a 5000 year old vase that is made of almost pure antimony.

Today, neither metallic antimony nor its compounds have a medical use, although up to the 1970s, antimony compounds were used to treat parasitic infections like schistosomiasis. These preparations did kill the parasites, but sometimes they also dispatched the patient. Up to the early twentieth century, tartar emetic was used as a remedy, albeit an ineffective one, for alcohol abuse. The New England Journal of Medicine once reported a case of a man whose wife tried to cure him of his alcoholic habit by secretly putting tartar emetic into his orange juice. The result was a trip to the hospital with chest pains and liver toxicity. Two years later the man reported complete abstinence from alcohol. Seems antimony had taught him a lesson.

Joe Schwarcz PhD

Electronic Waste

electronic wasteSome people are concerned about radiation from cell phones possibly causing brain tumours. Others worry about exposure to wi-fi causing cancer. And now I’m getting questions about whether cell phones are toxic because they contain benzene. No, cell phones do not contain benzene. Where does this notion come form? A misinterpretation of a quest by some environmental groups to have Apple in China stop using benzene along with another solvent, hexane, in the production of electronic equipment such as cell phones. This is a very legitimate endeavour but it is not the cell phone user who is at risk, it is the workers involved in the production of the equipment.

Proper functioning of the circuitry embedded in electronic chips requires that they be free of any dirt, and the same goes for touch screens. Benzene is an excellent solvent for cleaning chips and hexane is used to rinse touch screens. But there is a problem. Benzene is a carcinogen and hexane can affect the nervous system. As I often say, there are no safe or dangerous chemicals, only safe or dangerous ways to uses them. And unfortunately in China safety standards are lax and workers are commonly exposed to dangerous amounts of benzene and hexane. The incidence of leukemia due to benzene is unusually high, as are neurological symptoms due to hexane. Instituting proper safety systems with specialized ventilation is not likely to happen, but safer alternative solvents are available. Rubbing alcohol can be used instead of benzene and heptane is safer than hexane. This might add a little extra cost but would save a great deal of misery.

The solvents used in production are only one of the problems associated with our massive reliance on electronic goods. What to do with discarded equipment is a huge issue. Recycling usable parts is an obvious goal, but it only pays if cheap labour can be found. And that is available in China. There is valuable gold in microchips, as well as silver. There’s lots of copper in electronics, as well as palladium, platimun and ruthenium. There’s also iron, zinc, aluminum, cobalt, indium, gallium and selenium. All these have recyclable value. And then there are the hazardous metals suc as mercury, lead, beryllium, arsenic, cadmium and antimony. There’s also glass and various plastics.

The problem of course is to separate all these components which is a requirement for recycling. Workers often use bare hands to break the equipment apart and then heat the circuit boards to remove chips and solders, burn wires to get at copper and use strong acids to extract gold. Plastic parts are often incinerated to leave metals behind. Since polyvinyl chloride is a common plastic, there is a serious issue with the release of dioxins, highly toxic chemicals that form when chlorine containing organic compounds are heated to a high temperature. Nearby water get polluted and children are found to have high levels of lead. By law China is not supposed to import electronic garbage but nevertheless this happens routinely. And for what sort of pay do workers, many of them children, risk their health? About 17 cents and hour with an average workday being sixteen hours. This is something to think about next time you trade in that phone for one that you don’t really need.

 

Joe Schwarcz

Antimony in Plastic Water Bottles: Should I be worried?

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