In 1929, 7UP soda was advertised as a "Bib-label Lithiated Lemon-Lime Soda" and later 7UP Lithiated Lemon Soda. The popular drink did actually contain lithium citrate, a compound made from the element lithium, the same one found in today's lithium-ion batteries. There is no confirmed explanation for the 7 in 7UP, but some people have speculated it's because lithium's atomic mass is close to 7 (it's 6.94, but perhaps they rounded up).
Still, lithium citrate (lithium salt) was an ingredient in the beverage between 1929 and 1948 when the U.S. Food and Drug Administration (FDA) banned it from use in soda and beer.
Why were companies putting lithium in their beverages in the first place? For centuries, lithium hot springs were thought to be medicinal, and throughout the 1800s, lithium was used to treat gout — including "brain gout." It was also being prescribed in the late 19th and early 20th centuries for mania and melancholic depression, so the element had a good reputation.
But today lithium is in higher demand than ever before. And while most people probably think of the element in terms of batteries for laptops and EVs, the element is used for things well beyond technology. In fact lithium is still used to treat some mood disorders; it's been used in high-tech lenses at the FERMILAB proton conversion system for decades; and it helps stabilize glassware and ceramics. There are even some who believe microdosing it would be beneficial for mental health (more on that later).
Lithium is one of the lightest elements on Earth. Its atomic number is 3 and its atomic mass is 6.94. Like other metals, lithium is soft and malleable. It's silver in color, and has the density of a block of pinewood, says Michael McKibben, a research professor of geology in the department of Earth and planetary sciences at the University of California, Riverside.
Johan August Arfwedson discovered lithium in 1812 when he was decomposing lithium silicate minerals, including petalite, on the Swedish island of Utö. He found that petalite contained the previously unknown metal, lithium. "So Arfwedson and his professor decided to name the new element after the Greek word for stone, lithos, to reflect its discovery in minerals instead of plants and animals," McKibben says. Today, rocks are a primary source of lithium, though it's also found in hot springs and under dried lake beds.
For centuries, people were known to bathe in lithium hot springs for their perceived medicinal benefits, like those found in Lithia Springs, Georgia. The Sweet Water Hotel and and Health Resort that once stood there was so famous, people like Mark Twain, the Vanderbilts and several presidents, including Theodore Roosevelt, visited. Today, hot springs, geothermal areas and saline tend to have high amounts of lithium. Like pegmatites and granite, volcanic rocks contain a lot of lithium, McKibben explains. "Any process that weathers those rocks to clay, for example, or evaporative processes that concentrate brines, can further enrich the lithium in those settings where we find lithium being mined."
Soda, Batteries and Mood Stabilizers
"It's true that people think of batteries because that is about 75 percent of the use," McKibben says. "You can assess all the things you have that have lithium-ion batteries, and the list is growing: cars, drugs, bicycles, scooters, phones, tablets, mowers. I have a weed whacker that is lithium battery powered."
Despite the ban on lithium in beverages, it is an effective oral treatment for mood disorders today (you just don't consume it in lemon-lime soda). It's called Lithobid, but since the 1950s, pharmaceutical companies have added targeted synthetic alternatives.
Have you ever wondered how transition lenses work or why tinted windows get darker in response to the sun? The power of lithium!
"Many modern windows in houses turn dark in bright sunlight, and that's because of the lithium compounds in the glass," McKibben explains. "The lithium in glass is a layer of lithium ions that migrates in response to the sunlight and then darkens the glass." The other everyday use of lithium is in ceramics and glasses because lithium improves ceramic and glasses' durability and helps stabilize the color.
The Lithium Triangle
Lithium mining is booming today thanks mostly in part to the increase in EV vehicles and the demand for lithium for the rechargeable batteries. The race is on to mine the element and, though it has been mined in North Carolina, Nevada and Canada, most of the world's lithium comes from South America and Australia. The "lithium triangle" is a region where Chile, Argentina and Bolivia meet in the Atacama Desert. Here, lithium is pumped from beneath dry lake beds called salares, the Spanish word for dry lake beds, and then put into evaporation ponds.
The Atacama Salar is a salt flat in Chile and is the world's largest lithium producing deposit. It currently produces approximately one-third of the global lithium and is about the size of Yosemite National Park. "You can see them from space," McKibben points out. "They are huge. Each of those ponds is the size of a football field, and there are hundreds of them. That's what is thrashing the environment in Chile."
While mining processes vary (and can be highly secretive) they basically work like this: Lithium is extracted from a mineral-rich brine underground and is brought to the surface to evaporate in large basins. The remaining saline solution is treated in several stages until the lithium is ready for use. The process is very destructive to the surrounding environment. Plant life dies, lagoons dry up and local animals lose access to their usual breeding grounds.
"The ponds consume vast amounts of water and chemicals and produce daunting environmental damage to the Earth's surface. So that's why this concept of direct lithium extraction from geothermal brines and oil field brines has taken off in the last couple of years because those consume far less water and don't disturb the land," McKibben explains.
He also says that the footprint of a direct lithium extraction geothermal facility near the Salton Sea in California is about 100 acres (40.4 hectares) and consumes 10 times less water, and produces a lithium product in days. In contrast, the footprint of an evaporation pond in Chile is over 3,000 acres (1,214 hectares), and it takes two years to make lithium.
Is Lithium Dangerous?
We covered how lithium mining is harmful to the environment, but it can also have negative health consequences when consumed in large amounts and can be explosive under the right conditions.
"Lithium is comparatively unstable, it has just three protons in its nucleus, and it has a loosely held outer, unpaid third electron. It likes to give that third electron up easily," McKibben explains, and this makes it easy for lithium to react, especially with water, oxygen and nitrogen. "Uncoated lithium metal will react quite violently with water to form lithium hydroxide solution, and then hydrogen gas, which is flammable as a part of that reaction, releasing heat. So that's the reason for fires associated with lithium."
Lithium-ion batteries can catch fire because of the electrolytes in the batteries. McKibben says they are a flammable organic compound, and if there is a defect in a lithium-ion battery, it could short circuit. Or, the battery could be overheated or punctured from the outside, and both of these problems can cause lithium metal to react with water or air. The batteries have been responsible for several fires on airplanes and in airports over the last 10 years.
"That's when you get smartphones, laptops and car batteries that start burning," McKibben says. "Lithium battery fires are a growing hazard, especially in airplanes, and that's the worst place I can think of to have a battery fire." Researchers are continuing to search for a more stable — and less flammable — alternative to liquid or gel electrolytes.
As far as why the FDA banned lithium in soft drinks in the late '40s, it was simply because people were just consuming too much of it. And not just from their favorite sodas. They were getting it from their beer, as a medical treatment and even as a low-sodium alternative to table salt. People were overdosing on it and experiencing side effects of lithium toxicity, including nausea, vomiting, tremors and kidney damage.
Lithium Is Helpful, But Should We Start Drinking It Again?
Remember we said there were some who thought microdoses of lithium might be good for out mental health? In 2014, a psychiatrist and faculty member at Weill Cornell Medical College, Anna Fels, suggested in a New York Times OpEd article that we start researching the effects regular doses of lithium could have on society.
"The research to date strongly suggests that suicide levels would be reduced, and even perhaps other violent acts. And maybe the dementia rate would decline," she writes in her article, "Should we all take a bit of lithium?" Could a small dose of lithium in water supplies really reduce suicide, rape and murder rates across the U.S.? Fels seems to think that despite a bad reputation from a mid-20th century snafu, we should consider taking up the subject again.
And a 2020 meta-analysis of past studies published in the British Journal of Psychiatry that examined how naturally occurring lithium in tap water correlates with lower levels of suicide in local populations seems to agree with her. Right now, though, we'll opt for a soak in a mineral hot spring.