FACT: WE’RE ALL GONNA DIE
Life depends on death—living things die, decompose, and eventually become nutrients
that other life needs to live and grow. This circle of life has been going on forever. And
The Lion King’s version of it definitely glossed over the rotting and gross parts.
There are so many examples of this in nature. Young trees grow out of dead rotting trees,
and whale carcasses feed whole communities at the bottom of the ocean.
Everywhere you look death enables new life. Which is actually pretty cool.
But when it comes to humans, most of us end up embalmed and buried or cremated,
which means we’re breaking the circle of life, right? Are the rituals we humans have created
seriously messing things up?
First let’s take a look at what happens when a corpse decomposes out in the open.
We’re assuming that you’ve died in a relatively warm place, outside, on soil. There are three main
things we’ll focus on: our cells rupturing, our microbiome eating us, and scavengers eating us.
When you’re dead, you’re no longer breathing. That means you’re not taking in oxygen and releasing
CO2 like you do when you’re alive. As CO2 builds up and dissolves in your blood, it forms carbonic
acid, which dissociates into bicarbonate ions and hydrogen ions, which make your blood more acidic.
At the same time, enzymes in your cells that are normally involved in metabolism
start causing your cells to digest their own membranes. That, combined with a decreased blood
pH causes your cells to split apart and spill their guts, releasing a bunch of nutrients.
The second thing that happens, is that your microbiome, which is the
combination of all of the bacteria and viruses and fungi and other microbiota living in and on you,
starts eating you from the inside out, gobbling up the nutrients that your cells just spilled.
When you’re alive, your microbiome helps you digest food and keeps your
immune system in tip top shape. But when you die your immune system shuts down,
and all of a sudden trillions of bacteria now have free reign over your corpse.
They break down carbohydrates, proteins, and lipids, releasing even more nutrients
for even more bacteria to gobble up. That breakdown also produces a bunch of gases,
which will build up inside a corpse. That’s why corpses often look super bloated and start to
smell really, really bad. ​Carbon dioxide, methane and ammonia gases are part of the problem, as is
hydrogen sulfide, which is also in your farts. But putrescine and cadaverine, which are formed
from the breakdown of amino acids, are really the biggest culprits behind that “death” smell.
And now we’re reached the third thing: Stuff that comes for us.
Fungi, bacteria, worms, and insects will all show up to the dead body party.
There’s a mystery chemical we emit almost immediately when we die—scientists are
still trying to identify it. Whatever it is,
it somehow attracts blowflies within a few minutes. And they start laying eggs,
which hatch into maggots within days. One blowfly can lay several hundred eggs at a time,
so if a few hundred flies lay eggs, you’re gonna have tens of thousands of maggots pretty quickly.
So, what kinds of nutrients do you release?
For every kilogram of body weight, you release: 32g of nitrogen,
10g of phosphorus and 4g of potassium. I weigh about 70 kg, so 2,240g of nitrogen, 700 grams
of phosphorus and 280 g of potassium. The amount of potassium in 663 bananas. Hey, that’s not bad.
All of these compounds are super important for plant growth—they’re actually the three
main ingredients in fertilizer, which leads me to what I think is a very cool factoid.
Scientists who study human decomposition have a term for the area surrounding a corpse:
a cadaver decomposition island. It’s the spot where a corpse was that later becomes
a little oasis of vegetation. It comes from the fluid that leaks from you as bacteria
basically liquify your internal organs. First the vegetation in the cadaver decomposition island is
actually killed because of all of the ammonia you release, but then as the
nitrogen you /also/ release is broken down by bacteria in the soil, it acts as a fertilizer,
and your little vegetation oasis grows. That’s actually really peaceful to think about.
So does a common American burial, where you're preserved with embalming fluid and put in a coffin
that sometimes goes inside a concrete box and then you're buried at least 6 feet underground,
break the circle of life?
A coffin does make it much harder for the natural decomposition process to do it’s thing.
A lot of the same chemical transformations might still happen,
but much slower and the nutrients released are a lot more difficult for the living to reach from
six feet underground, especially if there’s concrete involved.
And if the person is embalmed it makes things even more complicated.
Embalming fluid is often formaldehyde, which bonds together a bunch of different molecules in cells,
like DNA and proteins, so tightly microbes can’t break them down. That’s the whole point
of embalming fluid -- to tie up our body’s molecules so they can’t be eaten by microbes.
That prevents decomposition long enough for… uh... an open-casket funeral. But the formaldehyde
doesn’t just stop working right after the funeral. In sealed glass jars,
formaldehyde can preserve tissues for 100 years or more. If microbes don’t break down a dead body,
all of those nutrients won’t get back into the earth:
so yes, the circle of life is cut short… or at least delayed for a really, really long time.
If all this just makes you want to be cremated, I get it. But that too has its own drawbacks.
Traditional cremation converts your body into mainly three things:
Water vapor, ash that ends up on a mantle fertilizing nothing...and
a lot of CO2, which, sure, plants need, but our atmosphere’s not really lacking in CO2 right
now. And the cremation process itself is super energy intensive, so it creates even more CO2.
You might be feeling kinda bummed out right now. Don't despair—people
have started realizing what we’re doing isn’t really fair to our fellow organisms,
so they’re opting for things like green burial in biodegradable coffins, or even human composting.
These aren’t legal everywhere but some states are starting to make it an option.
And body donation for forensic studies of decomposition is also an option. There are
facilities around the world that study that. And being an organ donor can put some critical
parts of you right back to work helping other people—no decomposition required!