Dead man decomposing

An excerpt from "Stiff: The Curious Lives of Human Cadavers," by Mary Roach.

Apr 17, 2003 |

Life After Death: On Human Decay and What Can Be Done About It

Out behind the University of Tennessee Medical Center is a lovely, forested grove with squirrels leaping in the branches of hickory trees and birds calling and patches of green grass where people lie on their backs in the sun, or sometimes the shade, depending on where the researchers put them.

This pleasant Knoxville hillside is a field research facility, the only one in the world dedicated to the study of human decay. The people lying in the sun are dead. They are donated cadavers, helping, in their mute, fragrant way, to advance the science of criminal forensics. For the more you know about how dead bodies decay -- the biological and chemical phases they go through, how long each phase lasts, how the environment affects these phases -- the better equipped you are to figure out when any given body died: in other words, the day and even the approximate time of day it was murdered.

To understand how these variables affect the time line of decomposition, you must be intimately acquainted with your control scenario: basic, unadulterated human decay. That's why I'm here. That's what I want to know: When you let nature take its course, just exactly what course does it take?

My guide to the world of human disassembly is a patient, amiable researcher named Arpad Vass. Vass has studied the science of human decomposition for more than a decade.

This morning, Arpad and I are riding in the back of a van being driven by Ron Walli, who handles media relations for Oak Ridge National Laboratory. ORNL also does research at the "body farm" -- as the decay facility is commonly known. Ron pulls into a row of parking spaces at the far end of the UT Medical Center lot, labeled G section. On hot summer days, you can always find a parking space in G section, and not just because it's a longer walk to the hospital. G section is bordered by a tall wooden fence topped with concertina wire, and on the other side of the fence are the bodies. Arpad steps down from the van. "Smell's not that bad today," he says. His "not that bad" has that hollow, over-upbeat tone that it has when spouses back over flowerbeds or home-hair-coloring goes awry.

Ron, who began the trip in a chipper mood, happily pointing out landmarks and singing along with the music on the radio, has the look of a condemned man. Arpad sticks his head in the window. "Are you coming in, Ron, or are you going to hide in the car again?" Ron steps out and glumly follows. Although this is his fourth time in, he says he'll never get used to it. It' s not the fact that they're dead -- Ron saw accident victims routinely in his former post as a newspaper reporter -- it's the sights and smells of decay.

Just inside the gate are two old-fashioned metal mailboxes on posts, as though some of the residents had managed to convince the postal service that death, like rain or sleet or hail, should not stay the regular delivery of U.S. Mail. Arpad opens one and pulls turquoise rubber surgical gloves from a box, two for him and two for me. He knows not to offer them to Ron.

"Let's start over there." Arpad is pointing to a large male figure about twenty feet distant. From this distance, he could be napping, though there is something in the lay of the arms and the stillness of him that suggests something more permanent. We walk toward the man. Ron stays near the gate, feigning interest in the construction details of a tool shed.

Like many big-bellied people in Tennessee, the dead man is dressed for comfort. He wears gray sweat pants and a single-pocket white tee shirt. Arpad explains that one of the graduate students is studying the effects of clothing on the decay process.

The cadaver in the sweat pants is the newest arrival. He will be our poster man for the first stage of human decay, the "fresh" stage. The hallmark of fresh-stage decay is a process called autolysis, or self-digestion. Human cells use enzymes to cleave molecules, breaking compounds down into things they can use. While a person is alive, their cells keep these enzymes in check, preventing them from breaking down the cell's own walls. After death, the enzymes operate unchecked and begin eating through the cell structure, allowing the liquid inside to leak out.

"See the skin on his fingertips there?" says Arpad. Two of the dead man's fingers are sheathed with what look like rubber fingertips of the sort worn by accountants and secretaries. "The liquid from the cells gets between the layers of skin and loosens them. As the process progresses, you see giant sheets of skin peeling off the body," says Arpad. He pulls up the hem of the man's shirt to see if, indeed, giant sheets are peeling. They are not, and that's okay.

Let us return to the decay scenario. The liquid that is leaking from the enzyme-ravaged cells is now seeping out, making its way through the body. Soon enough it makes contact with the body's bacteria colonies: the ground troops of putrefaction. These bacteria were there in the living body as well, in the intestinal tract, in the lungs, on the skin -- the places that came in contact with the outside world. Life is looking rosy for our one-celled friends. They've already been enjoying the benefits of a decommissioned human immune system, and now, suddenly, they're awash with this edible goo, issuing from the ruptured cells of the intestine lining. It's raining food. As will happen in times of plenty, the population swells. Some of the bacteria migrate to the far frontiers of the body, traveling by sea, afloat in the same liquid that keeps them nourished. Soon bacteria are everywhere. The scene is set for stage two: Bloat.

The life of a bacterium is built around food. Bacteria don't have mouths or fingers or Wolf Ranges, but they eat. They digest. They excrete. Like us, they break their food down into its more elemental components. When we die, they stop feeding on what we've eaten and begin feeding on us. And, just as they do when we're alive, they produce gas in the process. Intestinal gas is a waste product of bacteria metabolism.

The difference is that when we're alive, we expel that gas. The dead, lacking workable stomach muscles and sphincters and bed mates to annoy, do not. Cannot. So the gas builds up and the belly bloats. I ask Arpad why the gas wouldn't just get forced out eventually. He explains that the small intestine has pretty much collapsed and sealed itself off. Or that there might be "something" blocking its egress. Though he allows, with some prodding, that a little bad air often does, in fact, slip out, and so, as a matter of record, it can be said that dead people fart. It needn't be, but it can.

Arpad motions me to follow him up the path. He knows where a good example of the bloat stage can be found.

Ron is still down by the shed, effecting some sort of gratuitous lawn-mower maintenance, determined to avoid the sights and smells beyond the gate. I call for him to join me. I feel the need for company, someone else who doesn't see this sort of thing every day. Ron follows, looking at his sneakers. We pass a skeleton six feet seven inches tall and dressed in a red Harvard sweatshirt and sweatpants. Ron's eyes stay on his sneakers. We pass a woman whose sizable breasts have decomposed, leaving only the skins, like flattened bota bags upon her chest. Ron's eyes stay on his sneakers.

Next Page: "The brain liquefies very quickly. It just pours out the ears and bubbles out the mouth"

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