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Podcast Transcript
Sometime around eight to nine thousand years ago, ancient people in Asia Minor found a very dull grey metal that turned out to be easy to manipulate when it was heated.
For thousands of years, it was used for a variety of purposes, including as a food additive.
With the advent of the Industrial Revolution, even more uses were found for this unique metal.
However, by the 20th century, scientists realized that maybe this stuff wasn’t really so good for us.
Learn more about lead, how it has been used throughout history, and how our perception of it has changed on this episode of Everything Everywhere Daily.
As I’ve mentioned in several previous episodes, there were seven metals that were known to ancient people: gold, silver, tin, iron, copper, mercury, and lead.
I’ve done episodes on all of the other metals of antiquity, and this is the episode about the last of the seven metals, lead.
So, let’s do the basics of lead. Lead sits at the 82 position on the period table with 82 protons in its nucleus.
There are four stable isotopes of lead, and lead is often created as the end point of the decay chain of uranium-238, uranium-235, and thorium-232. Lead has the highest atomic number of any stable, non-radioactive element.
Lead naturally has a very dull grey color, making it one of the few metals that doesn’t have a shiny silver color.
One of the attributes of lead you are probably familiar with is its density. Lead has a very high density, which makes it useful for a host of applications, which I’ll get to in a bit.
Lead also has a relatively low melting point, which makes it easy to work with. Of the seven metals of antiquity, only mercury, which is a liquid at room temperature, and tin have lower melting points.
One other significant property of lead is that it does not corrode.
So with that, the earliest evidence of the human use of lead dates back about 8,500 years ago in Anatolia, modern-day Turkey. Small lead beads have been discovered, which might be evidence of the earliest human smelting of metal.
It is thought that the first attempts at lead extraction had nothing to do with lead per se. Its just that lead is often found alongside silver, and it might have been that the lead was smelted just to get access to the more attractive silver.
However, lead was eventually pursued for its own sake once its properties were better understood.
The first people to actually use lead were probably the ancient Egyptians. They used lead for a host of purposes, including cosmetics, glazing for pottery, weights for fishing nets, and ornamental use.
Many other cultures independently discovered the properties of lead all around the world.
In Mesopotamia, as well as in China, lead was used for simple coins. The Indus Valley civilization and civilizations in Mesoamerica used lead for simple jewelry and amulets.
In Eastern and Southern Africa, lead was used to create wire, which was one of the earliest examples of metal wire-making in history.
The Greeks were the first people to take advantage of the anti-corrosive feature of lead. They would create sheets of lead and use them to line the bottom of ships. This would not only inhibit the growth of barnacles, but the weight of the lead would serve as a ballast.
Another major use of lead was as ammunition for slings. Lead was heavy, and it could be shaped into a more lethal projectile. Lead was also occasionally used as a writing medium, as thin sheets of lead could be easily scratched.
The people who really took lead usage and lead production to another level were the Romans. They were, far and away, the biggest producers and consumers of lead in the ancient world.
The many ways, the Romans used lead in a similar way that we use plastics in the modern world.
Lead was very malleable, which made it very easy to shape. One of the biggest uses of lead was in aqueducts and water pipes. In fact, the Latin word for lead is plumbum, which is where we get the English word for plumbing. It is also why the chemical symbol for lead is Pb.
They used lead to line their baths and used lead for cookware. It was well known that storing food in lead containers would add sweetness to it in the form of sugar of lead, chemically known as lead acetate.
The Romans were producing about 80,000 tonnes of lead per year out of mines around the empire, although, as with the first users of lead, they primarily got their lead while pursuing silver.
After the fall of the Western Roman Empire, lead production around the Mediterranean dropped sharply. The new centers of lead mining were India and China.
In China, lead was used in metal alloys as well as many of the uses I described before.
In India, lead was used in traditional Ayurvedic medicine and was thought to have therapeutic properties….and yes, I know what you are thinking when you hear that, and I’ll be getting to it.
Back in Europe, around the 10th and 11th centuries, lead made a comeback. It was used as a major component in the creation of stained glass.
Both European and Islamic alchemists thought that lead was simply an impure form of gold. They both had similar properties in terms of density and malleability. This was why alchemists thought they could turn lead into gold. It was because they simply thought that gold was a purified version of lead.
Around this time, firearms came into use, and lead was found to be an ideal projectile. Lead projectiles had a high density, could easily be made with a wood fire, and were deformed on impact, causing more damage.
Lead was also the base of the pigment known as Venetian ceruse. It was a white powder that was used as a cosmetic as well as a powder in wigs. If you see an image of Queen Elizabeth I wearing white powder all over her face, it is Venetian ceruse.
It was also used to powder wigs in the 18th century.
When the printing press was developed, much of the movable type was created using a lead alloy.
Lead was also used as tiles for roofs because of their waterproof and anti-corrosion attributes.
Pewter, which was an alloy of lead and tin, became popular in the 17th and 18th centuries for use as plates and cups.
When the Industrial Revolution began in the 18th century, the demand for lead went up dramatically. It was the first time in centuries that lead production managed to equal the levels it did during the Roman Empire.
Lead was still used for ammunition, and the demand for ammunition only increased as wars became ever larger.
Lead continued to be used for plumbing, and demand for pipes increased as running water became more popular.
Lead was also found to be used in many paints as the addition of lead made for more durable paints that dried faster and resisted moisture.
Contrary to popular belief, lead was never used in pencils, even though it is commonly referred to as pencil lead. The name simply comes from confusion over the color, and some form of graphite has always been used.
One of the biggest uses of lead was in the creation of lead-acid batteries. Today, this is still the biggest use for lead in the world.
In 1921, lead was added to gasoline as an anti-knock agent to make cars drive better.
So, you can see that lead has had a host of uses throughout history in places all over the world.
However, there is a giant elephant in the room that I haven’t mentioned yet that I am guessing most of you thought of right away the moment you heard the topic of this episode.
Lead is toxic.
For thousands of years, people all over the world have been consuming lead directly or indirectly. The Romans used it for plumbing and carrying their water. They also used lead as a sweetener. In China, India, and other countries, lead was often administered as a medicine.
Lead was eventually used to make glass in the form of crystal ware, which was again used to drink out of.
Lead poisoning was something that had been known for a long time. The Roman architect Vitruvius wrote about the dangers of lead poisoning over 2000 years ago. The Romans knew it as “saturnine” gout.
It wasn’t until the 20th century that we realized just how bad lead could be.
For starters, there is no known biological need for lead at any level. There are certain elements that are required for human metabolism in very trace amounts, such as Selenium and Chromium. However, there appears to be zero need for lead.
However, the human body can bioaccumulate lead over a lifetime, and it can collect in your bones and organs. Because lead can accumulate, even low amounts of lead can become lethal over long periods of time.
Lead poisoning can cause developmental delays, learning difficulties, and behavioral issues in children, along with neurological symptoms, gastrointestinal problems, and anemia. In adults, it can lead to memory loss, mood disorders, muscle and joint pain, reproductive issues, and hypertension, with symptoms varying between acute and chronic exposure.
In 1983, environmental chemist Jerome Nriagu wrote an academic paper where he proposed the Roman Empire eventually fell due to lead poisoning….however, his thesis has been roundly rejected by pretty much everyone.
The movement to ban lead seriously began with the discovery by Clair Patterson, whose story I told in a previous episode, that lead was showing up everywhere in the environment due to its use as a gasoline additive.
Over the last several decades, lead has been removed from almost everything. Paint is now almost universally lead-free, as is fine crystal.
That doesn’t mean you can’t touch lead or that it is as bad as something like mercury, but it does mean you absolutely should not be ingesting it.
Despite the bans and concerns around lead, lead production has been going up globally. Today, lead production is near its all-time high.
About 10 million metric tons of lead is produced annually, and over half of that actually comes from recycling. The world’s largest producers are, in order, China, Australia, and the United States.
About 80% of all lead produced today is used in lead-acid batteries. Lead-acid batteries are the type that are used in a car, and the lead is why those batteries are so heavy.
Lead-acid batteries still have many advantages, including being rechargeable and cheap. In addition to automobiles, they are also often used in home renewable power setups.
The other 20% of global lead production mostly goes towards the creation of glass. High-quality glass still uses lead, but it can no longer be used for dinnerware.
Normally when I do an episode on an element, I can say that somewhere around you is something made out of that element. In the case of lead, that is probably not the case unless you happen to be in your car right now.
That places lead in a very unique category of metals. It is one that used to be more important than it currently is today.
That is all due to the realization of just how dangerous lead is and decades-long attempts…. To get the lead out.
The Executive Producer of Everything Everywhere Daily is Charles Daniel.
The associate producers are Peter Bennett and Cameron Kieffer.
Today’s review comes from listener Michael Elliott over on Spotify They write:
This show makes me happy, daily. I’m constantly impressed with how Gary distills complex ideas into understandable yet accurate narratives. And he never mispronounces tricky words. Gary is the best.
Thanks, Michael! I can assure you that despite my best efforts, I pronounce things wrong all the time, especially proper nouns from other languages. Thankfully, unless you happen to speak that language you probably just don’t realize it, which is why I can get away with it.
Remember, if you leave a review or send me a boostagram, you too can have it read on the show.