Et tu, Plumbum? Then Fall, Caesar’s IQ!

Lead is a very, very bad thing to be exposed to. Children poisoned by lead suffer permanent negative health impacts, particularly with regards to development of the central nervous system, while lead exposure in adults can lead to high blood pressure, cardiovascular disease, and kidney damage. Leaded gasoline blighted an entire generation of children in the 1960s and 1970s, costing those born during those years an average 6 or 7 IQ points. Fortunately, with the banning of leaded gasoline in 1996, children now only have microplastics to stunt their intellectual development.

One might imagine that lead poisoning is a modern-day problem, a result of the Industrial Revolution and internal combustion engines. But that’s not the case. Despite physicians of the era recognizing lead as a poison and documenting cases of lead poisoning, it was very prevalent during the age of both the Roman Republic and Empire. A popular theory in the 1980s even posited that Rome’s fall could be directly linked to lead exposure.  

That hypothesis has been largely debunked, but ancient Romans were undeniably exposed to large amounts of lead, and a recent study published in PNAS has been able to quantify both how much lead the Roman civilization poured out and what the cognitive effects of so much lead pollution were. To do this, they analyzed cores of ice from places like Greenland and Antarctica, where atmospheric lead has settled among the slowly building glaciers. These cores, some as long as 11,000 feet, contain records of atmospheric anomalies stretching back eons. 

For a pre-industrial civilization, the Romans were exceptionally skilled at pouring lead over the course of their thousand-year history, mostly as a byproduct of large-scale silver mining all over the empire. Galena, the mineral the Romans pulled silver from, also contains lead, so much so that for every ounce of silver they extracted, a thousand ounces of lead were released into the atmosphere. 

While the atmospheric lead concentrations during Roman times were a fortieth of what was reached during the 1970s, the Romans still managed to release over 500 kilotons of lead into the atmosphere during the 200-year Pax Romana at the start of the first millennium AD. This was enough to raise childhood blood lead levels by 2.4 mcg/dL — today, 3.5 mcg/dL is enough to necessitate medical intervention — and reduce the average IQ of the European population at the time by 2-3 points. 

That “doesn't sound like much, but when you apply that to essentially the entire European population, it's kind of a big deal,” study coauthor Nathan Chellman of the Desert Research Institute in Nevada said in a press release. Indeed, with a bit less lead in the air, perhaps Caesar could have had the foresight to see that knife coming.

Even In Medicine, All Roads Lead To Rome

The world is hardly lacking for public health crises and challenges. Increasing cancer rates, especially in younger people; the complicated effects that climate change will have on our health, particularly when it comes to things such as heat waves; the enduring obesity/diabetes crisis; America's own inimitable disaster of a health care system. The list goes on, really, but one thing that has to go near the top is our struggle against antibiotic-resistant infections. 

Credit: Bath & North East Somerset Council

For those of us sitting in comfortable homes, living generally healthy lives, this particular dilemma isn't one we have to worry about. The average middle-class American isn't going to stumble across a deadly superbug over the course of our day-to-day routine. But rest assured, antibiotic resistance is an issue; in 2019, over a million people died as a direct result of antibiotic-resistant infection, with it contributing in part to nearly 4 million more. By 2050, the number of deaths could reach 10 million a year, with it costing the world a trillion dollars.

While there are always weird, terrible people out there to disagree about anything, most of us see those numbers as something probably best avoided. The problem is that we've kind of hit a brick wall with discovering new antibiotics to beat out those nasty, antibiotic-resistant superbugs like MRSA. Traditionally, we've used bacteria living in regular, everyday locations like the soil (or in bread), but at this point, we've found every possible chemical and compound from those sources. When we go back to the tap, all we do is rediscover the same compounds we've already used and exhausted.

The solution, then, is to search for new potential antibiotics in locations we haven't drained of all value or novelty. Someplace new. Or someplace very old.

The Roman Baths in Bath, England, is the only geothermal spring in the United Kingdom, with the water coming out of the ground at a toasty 42 °C (about 107 °F) before settling into a more comfortable 30 °C at the Great Bath. The water there is mineral rich and has been used as a curative treatment by people for thousands of years. It's also filled with numerous microorganisms found nowhere else on Earth, which is what a group of British researchers was interested in.

In particular, the researchers focused on the King's Spring, which is where the water is at its hottest. During testing against a group of common antibiotic-resistant pathogens (the ESKAPE group), 15 strains of bacteria showed significant broad-spectrum antibiotic activity; a particular standout was a variety of Clostridium swellfunianum, which strongly inhibited multiple Gram-negative pathogens when living at its preferred temperature of 45 °C. This, the researchers said, drives home the point that we should test bacteria in their native conditions to maximize their antibiotic-producing potential.

Naturally, we can't just slap these new, helpful bacteria onto someone suffering from an antibiotic-resistant infection and call it a day. The researcher plan to sequence the genomes of the bacteria they found so that the specific genes responsible for the antibiotic activity can be identified. Once we know that, then we can start making novel antibiotics for our fight against antibiotic-resistant pathogens. The fact that their research involves spending a lot of time at a beautiful, relaxing hot spring is purely coincidental, I'm sure. "Oh, geez, we're all out of bacteria to test on, we'll have to go spend the day at the spa, collecting more. Oh, what an awful predicament this is." They truly are the bravest of souls over there in England.