Are dead or decomposing bodies dangerous?
Shout it from the rooftops:
“A person who dies is not, in themselves, a health threat to people around,” Dr. David Nabarro, executive director for sustainable development and healthy environments at the World Health Organization, said Wednesday.
“After a number of hours, the pathogens inside the dead person’s body become not dangerous. They usually decompose and die. And the dead person therefore is not a primary threat to the health of others.” via Corpses Pose Little Threat
Despite what you may believe, or what pop culture may have told you, the dead body is not dangerous! Even a decomposing body (which, let’s face it, is not altogether pleasant) is safe. The bacteria involved in decomposition are not the same bacteria that cause disease. Even maggots and insects present no threat to public health.
I talk you through it in one of my favorite Ask a Mortician episodes– Are Dead Bodies Dangerous?
But what if the decomposing body had an infectious disease?
It is true there are some exceptions to the “every dead body is safe” rule.
Dead bodies that are safe: Trauma and accident victims, cancer deaths, heart deaths, liver deaths, stroke deaths, on and on.
Dead bodies that may not be safe: Bodies that died of specific, rare infectious diseases such as ebola, avian bird flu, tuberculosis, hepatitis b & c.
But, here’s the thing, when is the last time you heard of someone in your town dying of ebola or tuberculosis? In the developed world, we have largely moved away from such infectious disease deaths. That’s not to say it’s impossible, just that these are the teeny tiny slim exceptions that prove the rule that bodies are overwhelmingly safe to be around and handle.
What is the process of decomposition like?
The rise in forensic human decomposition research centers (sometimes called Body Farms) has taught us so much about human decomposition, and how it proceeds in different environments.
Decomposition begins several minutes after death, with a process called autolysis, or self-digestion. Soon after the heart stops beating, cells become deprived of oxygen, and their acidity increases as the toxic by-products of chemical reactions begin to accumulate inside them. Enzymes start to digest cell membranes and then leak out as the cells break down. This usually begins in the liver, which is enriched in enzymes, and in the brain, which has high water content; eventually, though, all other tissues and organs begin to break down in this way. Damaged blood cells spill out of broken vessels and, aided by gravity, settle in the capillaries and small veins, discolouring the skin.
Body temperature also begins to drop, until it has acclimatised to its surroundings. Then, rigor mortis – the stiffness of death – sets in, starting in the eyelids, jaw and neck muscles, before working its way into the trunk and then the limbs. In life, muscle cells contracts and relax due to the actions of two filamentous proteins, called actin and myosin, which slide along each other. After death, the cells are depleted of their energy source, and the protein filaments become locked in place. This causes the muscles to become rigid, and locks the joints. via The Science of Human Decomposition
Visit a body farm (warning: graphic images) to get an up close view of what real– not zombie or crime show– decomposition looks like in this video from Vox.
Hear more about how food is digested (or not digested) post mortem in Ask a Mortician–Last Meals & Fossilized Poop.
Can you tell me about rigor mortis and other postmortem changes?
Rigor mortis is the stiffening of the muscles two-six hours after a death occurs.
At the moment of death, the muscles relax completely—a condition called “primary flaccidity.” The muscles then stiffen, perhaps due to coagulation of muscle proteins or a shift in the muscle’s energy containers (ATP-ADP), into a condition known as rigor mortis. All of the body’s muscles are affected. Rigor mortis begins within two to six hours of death, starting with the eyelids, neck, and jaw. This sequence may be due to the difference in lactic acid levels among different muscles, which corresponds to the difference in glycogen levels and to the different types of muscle fibers. Over the next four to six hours, rigor mortis spreads to the other muscles, including those in the internal organs such as the heart.
After being in this rigid condition for twenty-four to eighty-four hours, the muscles relax and secondary laxity (flaccidity) develops, usually in the same order as it began. The length of time rigor mortis lasts depends on multiple factors, particularly the ambient temperature. via Death Reference
I've heard that corpses can move or sit up on their own - can that really happen?
“Move on their own” implies they are willfully moving. It implies the brain or spirit still animates the body, and they’ve made a choice to change positions. Alas, after death, our bodies become slaves to the biological changes happening inside of us.
As the bacteria consume our insides, they release gas and waste. This causes the abdomen to bloat. We many be dead, but it’s a life-filled party inside our dead bodies. If the body is moved, built up gas may cause the body to moan or change positions. Muscles can continue to fire in strange ways after death as well. So it’s not out of the realm of possibility to see a body twitching, making small movements, or small noises. That’s just all the post mortem changes happening inside.
But any tales of the body sitting straight up, raising a hand toward you, and wailing, are likely the product of tall tales or overactive imaginations.
But...don't dead bodies poop?
Why yes. They can and do poop. But not always, by any means!
Enjoy this Ask a Mortician on the realities of Corpse Poo.