[PBSDS BUMPER] The average person gets rid of approximately 130 grams of poop every day.

Maybe twice that much if they've had Taco Bell.

Seven and a half billion of us on Earth?

That's a literal mountain of human poop every day.

Yet most of *us * get to pretend it doesn't exist, all thanks to an invention that has improved health and quality of life more than any other in humanity's history.

[OPEN BUMPER] Bears do it in the woods, whales do it in the ocean, and 2.4 *billion * of us DON'T do it in a toilet.

Dysentery, typhoid, parasites, and other infections lead to hundreds of thousands of deaths every year, all because one in three people alive in 2017 don't have access to toilets and latrines.

From on top of our porcelain thrones, we've left a lot of our species drowning in feces.

Nearly a *billion * people still defecate out in the open: in street gutters, open water, or... in the woods.

Thousands of years ago, we all did it that way, but as we developed agriculture and settled into towns, poop started piling up.

Around five thousand years ago, Neolithic villagers constructed the first known toilets at Skara Brae.

At the same time, many houses in Mohenjo Daro, featured toilets complete with drains, people washed their poop into sewers that emptied into the Indus River.

It'd be thousands of years before we linked germs to disease, but avoiding filth has deep evolutionary roots.

Bodily excretions, death, and rotten smells can be signs of danger or disease, triggering our innate sense of disgust.

This biological instinct ended up in the moral codes of many religions, like this passage from the Old Testament instructing the Hebrews to do their Exodus in a... hole-y fashion.

Roman society was comfortable with caca.

At one point, Rome had 144 public toilets... long open benches that emptied into the Cloaca Maxima, a sewer system that carried waste to the Tiber river.

But the vast majority of Romans simply pooped in a pot and threw it into the street.

As waste and disease piled up, Romans pointed to the stink as the cause of sickness.

After the Roman Empire faded away, this connection between bad air and bad health persisted, clogging up toilet innovation for more than a thousand years.

During medieval outbreaks like the Plague, doctors wore pointed masks, filled with strong herbs or perfumes to "cleanse" bad air, which they believed to be the cause of disease.

They were wrong, but this obsession with stink would change the world in ways no one saw coming.

Contrary to popular belief, Thomas Crapper didn't invent the flush toilet.

That honor goes to John Harington, his "Ajax" device emptied the bowl with water from an overhead tank.

But flush toilets didn't catch on until 1775, when Alexander Cummings revolutionized the way we poo by adding a water-filled "S trap" to block explosive, and supposedly disease-causing sewer gas from rising up the pipes, the same basic toilet design we still use today.

During the Industrial Revolution, most people's business still ended up in streets and cesspools, and the growing population was too big a load for London's sewers.

By the mid-1800s, the city was literally overflowing with crap.

With crap comes cholera, an infection from bacteria whose toxins basically cause all the water in your body to pour out of your butt in the form of diarrhea, death by dehydration.

Cholera hit London in 1854.

Instead of the "old bad air" theory, a doctor named John Snow believed cholera was transmitted by drinking water tainted with sewage.

Snow's map of cholera cases clustered around a water pump.

When he when he removed the pump's handle, new cholera cases fell.

Soon after, London enclosed its sewers and diverted waste downstream of London, but doctors wouldn't totally accept Snow's ideas for nearly 50 years.

The Great Depression saw an expansion of sewage treatment plants-and modern toilet paper!-and this is basically the sanitation system we have today, where magical chairs make nasty things disappear, out of sight, out of smell, and out of mind.

It's no three sea shells but we've come a long way.

...and this privileged pooping existence lets us keep something else out of mind: The 2.4 BILLION people who still don't have toilets.

Nearly 800,000 children under 5 still die every year from diarrhea.

More than AIDS, more than malaria.

That's an Airbus A380 full of children crashing every 6 hours.

It's estimated last year poor sanitation cost the global economy $260 billion, due to illness, loss of income, and years of life lost.

Worse, women suffer these impacts disproportionately to men.

In 2007, readers of the BMJ voted "modern sanitation" as the #1 medical advance since 1840.

Not antibiotics, not vaccines.

Toilets and clean water.

We *have * made progress.

Since 1990, 14% more people have access to sanitation, and *many * fewer are dying, but fewer is not zero.

With a little effort, we can *wipe * this problem from the Earth.

On the TV show "The Brady Bunch", their bathroom didn't even have a toilet.

Pooping is so taboo, it was *literally * invisible.

We can't even talk about it!

It's no coincidence that many of our worst swear words involve defecation.

In her book The Big Necessity, Rose George writes: "How a society disposes of its human excrement is an indication of how it treats its humans too" Everybody poops, and every person who is born should be able to do it safely.

Stay curious!

And please... always wash your