Historically, arsenic was known as both the "king of poisons" and the "poison of kings," for its toxic power and its popularity among rulers who wanted to quietly do away with their rivals, according to a 2011 study published in the journal Toxicological Sciences (opens in new tab). .

Whorton's book "The Arsenic Century (opens in new tab)" (Oxford University Press, 2010), Whorton recounted the legend of Roman emperor Nero ridding himself of his 13-year-old stepbrother and potential rival Britannicus by slipping arsenic into his soup.

The use of arsenic in murder was common until the development in te 18th century of chemical methods of detecting arsenic poisoning, which involve looking for the element in hair, urine or nails, according to Britannica (opens in new tab).

People are most frequently exposed to arsenic through drinking water in areas where arsenic levels in dissolved minerals are naturally high, according to the CDC (opens in new tab)?

(Rice absorbs an unusual amount of arsenic from the soil compared with other crops, according to the FDA (opens in new tab); the agency notes (opens in new tab) that arsenic may make its way into apple and other juices due to naturally high levels of arsenic in soil and water, past use of arsenic-based pesticides in the United States and current use of such pesticides in other countries.).

Arsenic's similarity to phosphorus means that "arsenic can substitute very easily for phosphorus in many fundamental chemical reactions in biology and disrupt them," Jones said.

"This means that arsenic can act like a broad-spectrum poison against insects, weeds and pretty much every life-form.".

For example, phosphorus helps cells generate adenosine triphosphate (ATP), which is the main source of energy in all known organisms, according to the American Chemical Society (opens in new tab)?

Long-term exposure to high levels of arsenic in drinking water is linked to medical conditions such as skin disorders, an increased risk for diabetes, high blood pressure, and several types of cancer, including lung and skin cancers, the CDC (opens in new tab) says.

Individual susceptibility to arsenic poisoning varies widely; some people can tolerate doses of the element that would kill others, according to Britannica.

Despite its deadly potential, arsenic poisoning is treatable if caught early, according to the Agency for Toxic Substances and Disease Registry (opens in new tab).

The drug works by absorbing arsenic and neutralizing its toxicity, according to the National Library of Medicine (opens in new tab). .

Although arsenic has a reputation for being deadly, it can also help cure disease, according to the Wellcome Library in England (opens in new tab).