Arsenic achieved infamy centuries ago as an almost odorless and tasteless poison that was often used by and against the ruling classes in Europe during the Middle Ages and Renaissance.
But what is the history of arsenic poisoning and how does it kill?
It turns out that an essential element of life also plays a role in making arsenic deadly.
What is the history of arsenic poisoning?
Arsenic is a naturally occurring element that is widely distributed in the earth’s crust, according to the Centers for Disease Control and Prevention (CDC) Agency for Toxic Substances and Disease Registry (opens in a new tab). Pure arsenic – which is a steel-gray, brittle solid – is usually found in the environment in combination with other elements, such as oxygen, chlorine, sulphur, carbon and hydrogen, which often gives white or colorless powders with no particular odor or taste. . As such, you generally cannot tell if arsenic is present in food, water, or air.
Historically, arsenic was known as both the ‘king of poisons’ and the ‘poison of kings’, for its poisonous potency and its popularity among leaders who wanted to quietly dispose of their rivals, according to a 2011 study published in the magazine Toxicological sciences (opens in a new tab).
Stories abound describing the deadly use of arsenic. For example, in biomedical historian James C. Whorton’s book “The century of arsenic (opens in a new tab)(Oxford University Press, 2010), Whorton told the legend of the Roman Emperor Nero getting rid of his 13-year-old half-brother and potential rival Britannicus by slipping arsenic into his soup.
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Powerful and wealthy Italian families, such as the Medici and the Borgia, also allegedly used arsenic to eradicate their rivals, according to the Toxicological Sciences report. The use of arsenic in murders was common until the development in the 18th century of chemical methods of detecting arsenic poisoning, which involved looking for the element in hair, urine or fingernails. , according to Britannica (opens in a new tab).
Today, arsenic poisoning is more likely to be accidental than deliberate. People are most often exposed to arsenic through drinking water in areas where levels of arsenic in dissolved minerals are naturally high, According to the CDC (opens in a new tab). Other sources of accidental exposure to arsenic include contact with contaminated soil or dust, wood that has been preserved with arsenic compounds, or certain foods, such as rice and some lemon juices. fruits. (Rice absorbs an unusual amount of arsenic from the soil compared to other crops, according to the FDA (opens in a new tab); the agency Remarks (opens in a new tab) that arsenic can enter apple and other juices due to naturally high levels of arsenic in soil and water, past use of arsenic pesticides in the United States, and the current use of these pesticides in other countries.)
What makes arsenic toxic?
The toxicity of arsenic comes from its proximity to phosphorus on the periodic table of elements. Because arsenic and phosphorus have similar atomic structures, they have similar properties. Both possess chemical keys that unlock access to cellular function. But while phosphorus is essential for life, arsenic is disruptive and deadly, Mark Jones, a chemical consultant and member of the American Chemical Society, told Live Science.
Arsenic’s similarity to phosphorus means that “arsenic can very easily substitute for phosphorus in and disrupt many fundamental chemical reactions in biology,” Jones said. “This means that arsenic can act as a broad-spectrum poison against insects, weeds, and just about every form of life.”
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For example, phosphorus helps cells generate adenosine triphosphate (ATP), which is the main source of energy for all known organisms, according to the American Chemical Society (opens in a new tab). Arsenic can mimic phosphorus in chemical interactions where enzymes use oxygen to help release energy stored in sugar glucose and capture it in ATP. This can cause arsenic to disrupt vital chemical reactions in which phosphorus participates.
“You can think of enzymes and the chemicals they act on like locks and keys,” Jones said. “Arsenic is like a key that is not cut properly – if it enters the lock of a door, not only will it not unlock that door, but it can get stuck in it and prevent another key from unlocking. come in to unlock that door. that way arsenic can block many vital chemical pathways.”
By chemically blocking cellular “locks”, arsenic can damage almost every organ in the human body. Large doses can cause symptoms such as vomiting, diarrhea, dehydration, shock, abnormal heart rhythms, and multiple organ failure, which can ultimately lead to death, according to the CDC. (opens in a new tab). Long-term exposure to high levels of arsenic in drinking water is linked to medical conditions such as skin disorders, increased risk of diabetes, high blood pressure, and several types of cancer, including lung and skin cancers, the CDC (opens in a new tab) said.
Individual susceptibility to arsenic poisoning varies widely; some people can tolerate doses of the element that would kill others, according to Britannica. In a 2018 study published in the journal mammalian genome (opens in a new tab)Researchers have reported that people’s genes, diet and gut microbes can affect their chances of surviving an encounter with the deadly toxin.
Despite its deadly potential, arsenic poisoning can be treated if detected early, according to the Agency for Toxic Substances and Disease Registry (opens in a new tab). A key drug is dimercaprol, which was developed by British scientists during World War II as an antidote to arsenic-based chemical weapons. The drug works by absorbing arsenic and neutralizing its toxicity, according to the National Library of Medicine (opens in a new tab).
Although arsenic has a reputation for being deadly, it can also help cure illnesses, according to the Wellcome Library in England (opens in a new tab). In 1909, German chemist and Nobel laureate Paul Ehrlich and his colleagues developed an arsenic-laden compound called Salvarsan, which became the first effective treatment for syphilis. according to the Science History Institute of Philadelphia (opens in a new tab). Salvarsan’s working principle, whereby a drug seeks out and destroys diseased cells, eventually found use in chemotherapy, Wellcome Library reported.
Originally posted on Live Science.