9 Facts About Human Decomposition

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From rotting corpses crawling with maggots to oozing bodies emitting stomach-churning stenches, the decaying human body is the stuff of nightmares, horror movies, and crime dramas. We're both fascinated and repelled by decomposition, which has given rise to many myths and urban legends. (No, hair and nails don't grow after death, and corpses never sit up on mortuary tables.) Here are nine fascinating facts that demystify how we transition from flesh to bone to dust.

1. DECOMPOSITION STARTS ALMOST IMMEDIATELY AFTER DEATH.

It takes approximately four minutes from the moment a person has breathed their last for the shortage of oxygen in their body to kick off a series of events happening at the microscopic level: The levels of carbon dioxide and acidity rise in the bloodstream, and toxic wastes build up, poisoning the cells. Then, enzymes within cells begin to eat away at them. Organs with high concentrations of enzymes and water, such as the liver and the brain, are ground zero for this process.

One of the first visible signs of death is when the eyes cloud over, a result of fluids and oxygen no longer flowing to the corneas. That can begin within 10 minutes [PDF] of death.

2. THERE ARE FIVE PHASES OF DECOMPOSITION.

The first phase is called fresh. It's characterized by cell autolysis, "or self-digestion": The cells burst open due to the work of enzymes, and fluids leak out. Fluid-filled blisters emerge on the skin, which slips easily off the body in large sheets.

Meanwhile, resident anaerobic bacteria in the gut begin to break down cells, beginning the second phase of decomposition: bloat. As these microbes work away, gases begin to accumulate in the intestines, and the surrounding tissues expand. The gases react with hemoglobin, a protein found in red blood cells, producing a green pigment in the veins ("marbling"), and the skin turns green, then black.

During active decomposition, the third phase, tissues begin to liquefy and decomposition fluids seep out through orifices. According to Dawnie Wolfe Steadman, director of the Forensic Anthropology Center at the University of Tennessee, Knoxville, the loss of tissue mass is the chiefly the work of fly maggots—which feast on tissues—and bacteria.

Advanced decomposition is when most soft tissues are gone, whatever skin is left has turned dry and leathery, and the skeleton is visible, thanks to the handiwork of yet more bugs. "While the fly maggots no longer have much to feed on, other insects such as beetles come," Steadman says. "They are capable of breaking down the tougher soft tissues, like tendons, ligaments, and even cartilage."

Skeletal decay is the end of the decomposition process. A variety of factors result in the breakdown or fragmentation of bones. Acidic soil, for example, dissolves an inorganic mineral compound called hydroxylapatite—a mix of calcium and phosphate—that accounts for 70 percent of our bone material [PDF]. Bones can also disintegrate when they are subjected to a variety of physical forces, including being gnawed on by scavengers or being slowly eroded by the flow of water.

How long each of the above stages lasts depends on factors such as temperature, burial conditions, and the presence of microbes, insects, and scavengers. Active decomposition in particular is greatly influenced by the temperature; flies lay their eggs in warmer months, so decomposition tends to be slower in colder temperatures. Bones generally begin to bleach within the first year, and algae and moss may grow on their surface. Large cracks tend to form after about a decade.

3. RIGOR MORTIS IS ONLY TEMPORARY.

Fans of shows like Law & Order: SVU are likely to be familiar with rigor mortis, or the stiffening of the body’s muscles following death. It begins within two to six hours, originating in the face and neck and spreading outwards toward the limbs. Rigor mortis is the result of the two types of fibers in our muscle cells—actin and myosin—becoming tightly linked by chemical bonds that develop in response to lower pH levels in the cells, creating inflexibility [PDF]. But this rigidity goes away within 1 to 3.5 days, as the bonds between the muscle fibers break and the muscles relax, once again starting with the face. As this happens, the body can release feces and urine.

Rigor mortis occurs more quickly and persists longer in cooler temperatures than in warmer ones; according to one study, rigor lasted for 10 days in corpses refrigerated at 39°F in a mortuary. What happens right before death can influence rigor mortis too: A high fever will shorten how long it lasts, while vigorous physical activity will cause it to set in sooner. These effects are likely caused by a drop in the levels of the chemical ATP (adenosine triphosphate), an energy driver in cells, and increased amounts of lactic acid, which lower the pH in muscle cells.

4. DECOMPOSITION DOESN'T SMELL AS BAD AS YOU'D EXPECT.

“People think bodies always smell awful,” says Melissa Connor, director of the Forensic Investigation Research Station at Colorado Mesa University. “But while there are a few times and phases [where the] remains are odiferous, for the most part, the smell is not overpowering.”

Malodorous gases build through the bloat phase, but the smells lessen as decomposition progresses. According to Connor, in the summer, a corpse can pass through the odiferous stages in 10 days or less.

A mix of gases is responsible for the “sickly sweet” stench of death. Of these, putrescine and cadaverine—produced when bacteria break down the amino acids ornithine and lysine, respectively—emit distinctive noxious odors. These gases can be absorbed through the skin and compete with or displace oxygen—a potential health risk for people working with decomposing bodies in closed environments, such as underneath a house or in a well shaft. A recent study suggests that putrescine may act as a warning signal that death is near, triggering a “flight-or-fight” response.

5. DECOMPOSITION CAN SOMETIMES CREATE "SOAPY" CORPSES.

Another stinky by-product of decomposition is a waxy substance called adipocere. It's formed from fat under wet conditions through a process called saponification (the same basic chemical reaction by which soaps are made from fats). Fresh adipocere smells like ammonia, but over time, adipocere dries out and the odor disappears. Philadelphia’s Mütter Museum has a specimen of a corpse encased in adipocere known as the Soap Lady, who was exhumed in 1875 from a city cemetery. The Smithsonian has a male counterpart: Soapman, who was also found in Philadelphia in 1875 during the construction of a train depot. He died around 1800.

6. THE 'NECROBIOME' COULD HELP US DETERMINE TIME OF DEATH MORE ACCURATELY.

Forensic entomologists use insects to infer time of death, but there are other potential biological clues. According to Steadman, forensic scientists are researching how different species of bacteria can influence decomposition, and if bacteria can help identify individuals.

"Some researchers are looking at the necrobiome—or all the little bacteria and fungi that inhabit a corpse—and seeing if changes in the necrobiome can inform time of death," Connor says. By knowing which strains of bacteria and other microbes are present at each phase of decomposition, scientists can put together a microbial clock to help estimate the time since death. Some of these microbes come from our own microbiome; others come from the surrounding soil, or are carried to the body by flies, other insects, and scavengers.

7. WITHOUT BUGS OR BACTERIA, DECOMPOSITION CAN SLOW WAY, WAY DOWN …

In December 1977, in Franklin, Tennessee, the Williamson County Sheriff was called to an antebellum estate called Two Rivers. The owners had reported a disturbance in the small graveyard attached to the estate. There, the sheriff’s department found a headless male corpse dressed in formal wear atop the broken coffin of a Confederate lieutenant colonel named William Shy, who had died in 1864. Forensic anthropologist William Bass was asked to examine the body.

In his book Death’s Acre, Bass writes that the corpse had been preserved in the early stages of decomposition; the "flesh was still pink," he notes. He estimated the man had been dead a year at most. But some things didn't add up, which puzzled Bass. The style of clothing was dated and the shoes were made of old materials. The corpse’s head was later found in the coffin, and the teeth had not seen modern dentistry. All of this led Bass to suspect that the body was in fact Shy’s.

Turns out he was right the second time around. Shy's corpse had been unceremoniously yanked out of his resting place by grave robbers. The 113-year-old body was so well-preserved because it was embalmed—which slows decomposition (by how much depends on the embalming process)—and because the cast-iron coffin was hermetically sealed, keeping out any insects and microbes that would have pushed decomposition beyond the early stages.

More recently, in May 2016, an airtight metal casket was unearthed in a backyard in San Francisco. The home had been built on the site of a cemetery. Inside the casket was the well-preserved body of a toddler, Edith Cook, who had died in 1876. News reports don’t explicitly state whether Edith was embalmed, but old ads from the casket’s manufacturers boast that it offered “perfect protection from water and vermin.”

Still, cast-iron coffins aren't decomposition-proof: In other cases, they've exploded due to bloat-stage gases. This gas buildup has been a problem for some modern "protective" or "sealer" caskets too.

8. … AND ENVIRONMENTAL CONDITIONS CAN ALTER DECOMPOSITION.

Certain environmental conditions are ideal for preserving bodies and creating natural mummies—which are unique because the skin survives active decomposition.

A combination of low oxygen, highly acidic water, and cool temperatures in European peat bogs turns corpses into bog bodies. While the acidic water breaks down bones, tannins in the peat and the lack of oxygen preserve skin—every expression, wrinkle, and fingerprint—with astonishing detail. Famous examples include the Tollund Man and Lindow Man.

La Doncella, or “The Maiden,” is an ancient Inca teenager who was left to die in the Andes Mountains in Argentina as a part of a ritual sacrifice. She was found in 1999, head down, appearing to be asleep. Though she died more than 500 years ago, her hair, skin, and clothing are all almost perfectly preserved. The high altitude, low temperatures, and low oxygen level account for La Doncella’s condition.

Another example of the preservative powers of the mountains is Ötzi, a natural mummy of a man who died about 5300 years ago. He was discovered in 1991 in Ötztal Valley Alps and has been preserved almost in his entirety. Though the glacier ice dehydrated his body, his skin, other tissues, organs and bones remain in great shape.

9. DISEASES THAT KILL THEIR HUMAN HOSTS CAN SURVIVE DECOMPOSITION.

A number of disease-causing viruses can hang around even after death. The Ebola virus is particularly contagious even after a person has died: It remains in their blood and other bodily fluids. Any contact with broken skin or the mucous membrane (which lines the nose, mouth, and other body cavities) of a healthy person is enough to pass on the infection. For this reason, the World Health Organization recommends that infected bodies be buried quickly and safely, with everyone handling the body wearing protective gear and the body buried in a coffin in the ground. The virus has been shown to persist in dead primates for up to a week.

Norovirus (the stomach flu) can also spread in a manner similar to Ebola, and it is possible to catch influenza from the infected mucus of a dead person. The smallpox virus remains in the scabs of a dead person for as long as a century—but at least it's not contagious from the dead to living.

Why You Should Never Flush Your Contacts Down the Drain

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When a pair of contact lenses reach the end of their short life span, it may be tempting to dump them—and the liquid they’re stored in—down the bathroom sink drain. As The Atlantic points out, though, this is bad for the environment.

However small and thin they may be, contact lenses can contribute to microplastic pollution in waterways when they’re not disposed of properly, according to a new study presented at the recent American Chemical Society national meeting in Boston. The study surveyed contact lens users and non-users, and found that 19 percent of users flush the lenses down the toilet or sink drain instead of placing them in the trash. That translates to about 3 billion contact lenses per year, Rolf Halden, a researcher at Arizona State University and one of the study's authors, told The Atlantic.

Halden said he was inspired to look into the issue out of personal interest—he, too, wears contact lenses—and because he couldn’t find any studies on what happens to lenses after they’re flushed down the drain. Halden and his team discovered that the lenses end up in wastewater, where they can sink to the bottom because they are denser than water. There, they could endanger aquatic life, especially bottom feeders that may ingest the particles.

Researchers also found that microbes in wastewater treatment plant systems can degrade the structure of the lenses themselves and break them into tinier pieces. In the larger environment, those bits could be consumed by every organism in the local food chain. In addition, some of the flushed lenses are turned into a treated sewage sludge that is ultimately used to fertilize crops, so the waste could end up in our soil and affect creatures like earthworms. The extent to which this affects humans' food supply is not currently known.

"Ultimately, we hope that manufacturers will conduct more research on how the lenses impact aquatic life and how fast the lenses degrade in a marine environment,” Halden says in a statement.

So the next time you’re done using your contact lenses, think of the fish and worms, and throw them in the trash instead.

[h/t The Atlantic]

Debunking 6 Common Home Remedies That Aren't Worth Trying

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While it’s never fun—or cheap—to go to the doctor, sometimes you just have to bite the bullet and make an appointment. While you may read a slew of articles online during your middle-of-the-night WebMD binge, the “natural” home remedies that some blogs swear by are often at best no better than placebos, and at worst actively harmful.

A new video from SciShow explores several home “remedies” that don’t actually help treat common medical issues. The nine-minute video debunks some of the "natural" treatments that people often cite as cures for ailments as benign as allergies or as serious as poisoning. Spoiler: Most of them have no scientific basis.

If, for instance, you’ve ever heard the idea that local honey can act as an allergy cure, put down the spoon. Despite being delicious, honey doesn’t provide enough exposure to the allergens that cause those sniffles and itches to help. When your seasonal allergies hit, take medication or visit an allergist instead.

How about the old custom of putting butter on a burn? Unsurprisingly, fatty foodstuffs don’t make great wound treatments. While people used to believe that burns shouldn’t be exposed to air, oily substances like butter will actually trap heat from your burn, making it worse. The key to treating a burn is cooling it off. You want to stick it in cool water, not warm butter.

If you are unlucky enough to catch head lice, you're probably willing to try whatever you can get your hands on to destroy the little critters. But that pricey medicated shampoo really is the best way to go. Scientists have found that washing your hair with vinegar isn’t the answer. Researchers have found that lice nesting in hair aren’t affected by vinegar, even when the hair in question is soaked for 8 hours.

Some of these home remedies seem a little out-there, but others are understandable. Ipecac syrup once had a place on every pharmacy shelf as a method of treating people who ingested poison. The syrup is poisonous itself, and it makes you vomit—but vomiting isn’t a guarantee that your body has rid itself of all the toxins, and it might just make it harder for your doctor to diagnose what’s going on. Poison Control no longer recommends keeping ipecac syrup on hand, and U.S. manufacturers stopped making it in 2010.

Tilting your head back to staunch a nosebleed is yet another common treatment that can backfire on you. Tilting your head back does stop the blood from flowing from your nose. But it means that your blood will flow down your throat instead of out your nose. So instead of getting a towel bloody, you put yourself at risk of choking on your own blood.

The last “remedy” SciShow tackles isn’t directly harmful, but it won’t help, either. Some people recommend treating pink eye by using warm chamomile tea bags as eye compresses. While chamomile does have some anti-inflammatory properties, there’s no evidence that chamomile is at all effective in treating pink eye. Draping warm tea bags over your eyes probably won’t harm you, and in fact, the heat may relieve some pain, but the tea itself isn’t going to cure you.

Dive into the facts behind these “remedies” in the video below. And remember: when in doubt, always go to the doctor.

[h/t Digg]

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