Get Panning: There’s Gold in Them Thar Doodies

Are you flushing away a fortune?

It’s undeniably true that average weekly grocery bills vary widely from person to person, family to family.

But after their journey through your gastrointestinal system (sorry for that image, but there’s worse to come), there’s simply no getting away from the place in which a substantial proportion of your food purchases end up.

Yup, the sewer.

In the 1980s, Mayo Clinic researchers calculated that the total transit time from eating to elimination is something like 53 hours.

This is a little over two days to turn that hard-won bag of groceries into what some researchers quaintly refer to as municipal sludge.

Of course, one person’s municipal sludge is another’s research gold, which is unquestionably the case for us at uBiome.

And actually, as we’ll see in a moment, the word “gold” may be more than a simple analogy.

Every day, our laboratory welcomes another wave of poop samples in their teeny tubes.

But since each holds the merest smear of an individual’s brown stuff, our daily share of the world’s fecal matter is a mere plop in the ocean compared to the gigantic quantity that humankind flushes away overall.

Researchers estimate its mass to be around 640 billion pounds – or 290 billion kilograms – per year.

And if you’ll forgive our forthrightness, this is one crapload of poop.

It’s 320 million tons, approximately the weight of fifty of Egypt’s Great Pyramids.

Of course, there’s a tendency for many to pull the handle as soon as possible after pooping, flushing away their evidence and thinking very little about it.

But what, exactly, is the economic value of all this flushed away feces?

Before we explore this, though, we should spare more than a thought for the estimated 2.4 billion people (more than one third of the world’s population) who have no access to advanced sanitation, including one billion who shamefully have no facilities of any kind.

Maybe we should remember this the next time we’re about to moan about slow internet speed.

But let’s return to the economic value of all we flush away.

If a hankie popped into the bowl with one of those food ingredients labels stuck to it, the first item on its list would be water.

Fecal matter is 55% – 75% water, a good reminder of how important proper hydration is for regular bowel movements.

Fascinatingly, however, if you dry and then concentrate human poop, it has a calorific value equivalent to coal, which casts a rather different light on the idea of throwing another log on the fire.

More seriously, a UN think tank estimated that if all human waste was converted to fuel, it would have a monetary value of around $9.5 billion.

In fact, just the waste products of the one billion who are completely without sanitation could produce enough methane, alone, to power 10-18 million households.

In addition, the solid matter left over would amount to the equivalent of roughly 8.5 million ton of charcoal for industrial use.

Instead, it’s discarded in ways that fouls water supplies, spreads infection, and destroys people’s overall quality of life.


Closer to home, the US Geological Survey has taken their own interest in matters fecal for another reason.

Dr. Kathleen Smith of the USGS delivered a presentation at the 249th National Meeting of the American Chemical Society, reporting that Americans produce about seven million metric tons of, ahem, biosolids each year.

About half is used as fertilizer on fields (note to selves: wash those fruits and vegetables tonight), while the other half is incinerated or sent to landfills.

But wait. There’s gold in them thar doodies.

You see, the reason the USGS is all excited is that scientists have detected microscopic amounts of precious metals in poop – including gold, silver, and platinum.

Apparently, the metals get into us through our interactions with a wide range of items, including hair products and detergents.

There can even be nanoparticles in socks, put there to prevent bad odors.

You don’t actually have to eat shampoo, laundry detergent, or socks to ingest metals, by the way.

Among other mechanisms, microscopic fragments can probably be simply inhaled or end up in your food.

Dr. Smith estimated that the annual output of one million people contains elements valued at $13 million.

Did someone just say thirteen?

Let’s examine, then, the thirteen most lucrative elements found in poop: silver, copper, gold, phosphorus, iron, palladium, manganese, zinc, iridium, aluminum, cadmium, titanium, and gallium.

It makes us sound like walking hardware stores.

Although some critics suggest it wouldn’t be economically viable to harvest these elements, the USGS suggested that the gold in poop is at a level they describe as “a minimal mineral deposit.”

If this equivalent occurred in rock, it would be considered a potential mining prospect.

It all goes to show that there really are new business opportunities all around us (and even in us).

Although, this may be the first time we can legitimately report that a market has fallen out of the bottom.

More Reading

Characterization, Recovery Opportunities, and Valuation of Metals in Municipal Sludges from U.S. Wastewater Treatment Plants Nationwide

Digestion: How long does it take?

Food Prices and Spending

Gold In Your Poop? Scientists Claim Millions Of Dollars In Metals Can Be Found In Human Feces

How Poop Can Be Worth $9.5 Billion

Rare earth metals from poop? Not so fast

Sewage – yes, poop – could be a source of valuable metals and critical elements

Solid Gold: Poop Could Yield Precious Metals

Sustainable Wastewater Management in Uganda