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Human urine is sterile as long as it is in the human body. But is it dirty after leaving the human body? Could you get sick from it, if you drink it or don't wash your hands, for example?
It was believed for a long time that urine stored in the urinary bladder is sterile. However, Wolfe et al(1). recently found evidence of bacterial presence in the urine extracted from bladders of healthy women. In an article just published, Hilt et al. found that at least some bacteria found in the bladder of healthy women are viable and can be grown in a laboratory after extraction from the bladder).2 (Paywall). They expect that the same is the case for men.
From the Hilt et al. paper:
Thirty-five different genera and 85 different species were identified by EQUC. The most prevalent genera isolated were Lactobacillus (15%), followed by Corynebacterium (14.2%), Streptococcus (11.9%), Actinomyces (6.9%), and Staphylococcus (6.9%). Other genera commonly isolated include Aerococcus, Gardnerella, Bifidobacterium, and Actinobaculum.
Note that these species for the most part (Actinobaculum being one exception, as a possible uropathogen) appear to be part of the normal microbiome (collection of microorganisms) in healthy people in the same way as bacteria inhabit other parts of healthy persons. Additionally, the recovered organisms required special care to achieve growth:
Most of the bacteria isolated required either increased CO2 or anaerobic conditions for growth, along with prolonged incubation, and they often were present in numbers below the threshold of detection used in routine diagnostic urine culture protocols.
Thus, fresh urine is non-sterile but probably unlikely to cause infection in healthy persons.
In the process of leaving the body, there is a chance of contamination from organisms living in the urinary tract or on the surface of the body. However, if organisms picked up from the urinary tract made you sick, I except that you would already be having symptoms of an urinary tract infection, as the stomach is hardly a more forgiving environment. The risk of contamination from the surface of the body would depend on personal hygiene.
See also this question on https://outdoors.stackexchange.com/questions/264/is-drinking-urine-safe
Edit: This might go without saying, but apart from possible pathogens, there are of course other aspects of urine which makes it unfit for general consumption.
Can humans drink seawater?
One of the instruments scientists can use to measure salinity is a CTD rosette, which measures the Conductivity (salinity), Temperature, and Depth of the water column.
Seawater contains salt. When humans drink seawater, their cells are thus taking in water and salt. While humans can safely ingest small amounts of salt, the salt content in seawater is much higher than what can be processed by the human body. Additionally, when we consume salt as part of our daily diets, we also drink liquids, which help to dilute the salt and keep it at a healthy level. Living cells do depend on sodium chloride (salt) to maintain the body’s chemical balances and reactions however, too much sodium can be deadly.
Human kidneys can only make urine that is less salty than salt water. Therefore, to get rid of all the excess salt taken in by drinking seawater, you have to urinate more water than you drank. Eventually, you die of dehydration even as you become thirstier.
Schistosomiasis, also known as bilharzia, is a disease caused by parasitic worms. Infection with Schistosoma mansoni, S. haematobium, and S. japonicum causes illness in humans less commonly, S. mekongi and S. intercalatum can cause disease. Although the worms that cause schistosomiasis are not found in the United States, more than 200 million people are infected worldwide.
How can I get schistosomiasis?
Infection occurs when your skin comes in contact with contaminated freshwater in which certain types of snails that carry schistosomes are living.
Freshwater becomes contaminated by Schistosoma eggs when infected people urinate or defecate in the water. The eggs hatch, and if certain types of freshwater snails are present in the water, the parasites develop and multiply inside the snails. The parasite leaves the snail and enters the water where it can survive for about 48 hours. Schistosoma parasites can penetrate the skin of persons who are wading, swimming, bathing, or washing in contaminated water. Within several weeks, the parasites mature into adult worms and live in the blood vessels of the body where the females produce eggs. Some of the eggs travel to the bladder or intestine and are passed into the urine or stool.
What are the signs and symptoms of schistosomiasis?
Within days after becoming infected, you may develop a rash or itchy skin. Fever, chills, cough, and muscle aches can begin within 1-2 months of infection. Most people have no symptoms at this early phase of infection.
When adult worms are present, the eggs that are produced usually travel to the intestine, liver or bladder, causing inflammation or scarring. Children who are repeatedly infected can develop anemia, malnutrition, and learning difficulties. After years of infection, the parasite can also damage the liver, intestine, lungs, and bladder. Rarely, eggs are found in the brain or spinal cord and can cause seizures, paralysis, or spinal cord inflammation.
Symptoms of schistosomiasis are caused by the body&rsquos reaction to the eggs produced by worms, not by the worms themselves.
What should I do if I think I have schistosomiasis?
See your health care provider. If you have traveled to countries where schistosomiasis is found and had contact with freshwater, describe in detail where and for how long you traveled. Explain that you may have been exposed to contaminated water.
How is schistosomiasis diagnosed?
Your health care provider may ask you to provide stool or urine samples to see if you have the parasite. A blood sample can also be tested for evidence of infection. For accurate results, you must wait 6-8 weeks after your last exposure to contaminated water before samples are taken.
What is the treatment for schistosomiasis?
Safe and effective drugs are available for the treatment of schistosomiasis. Praziquantel is the recommended treatment drug. See your doctor for appropriate diagnosis and treatment.
Am I at risk?
If you live in or travel to areas where schistosomiasis occurs and your skin comes in contact with freshwater from canals, rivers, streams, ponds, or lakes, you are at risk of getting schistosomiasis.
This Is What Happens to Your Body After You Die
“It might take a little bit of force to break this up,” says mortician Holly Williams, lifting John’s arm and gently bending it at the fingers, elbow and wrist. “Usually, the fresher a body is, the easier it is for me to work on.”
Williams speaks softly and has a happy-go-lucky demeanour that belies the nature of her work. Raised and now employed at a family-run funeral home in north Texas, she has seen and handled dead bodies on an almost daily basis since childhood. Now 28 years old, she estimates that she has worked on something like 1,000 bodies.
Her work involves collecting recently deceased bodies from the Dallas–Fort Worth area and preparing them for their funeral.
“Most of the people we pick up die in nursing homes,” says Williams, “but sometimes we get people who died of gunshot wounds or in a car wreck. We might get a call to pick up someone who died alone and wasn’t found for days or weeks, and they’ll already be decomposing, which makes my work much harder.”
John had been dead about four hours before his body was brought into the funeral home. He had been relatively healthy for most of his life. He had worked his whole life on the Texas oil fields, a job that kept him physically active and in pretty good shape. He had stopped smoking decades earlier and drank alcohol moderately. Then, one cold January morning, he suffered a massive heart attack at home (apparently triggered by other, unknown, complications), fell to the floor, and died almost immediately. He was just 57 years old.
Now, John lay on Williams’ metal table, his body wrapped in a white linen sheet, cold and stiff to the touch, his skin purplish-grey – telltale signs that the early stages of decomposition were well under way.
Far from being ‘dead’, a rotting corpse is teeming with life. A growing number of scientists view a rotting corpse as the cornerstone of a vast and complex ecosystem, which emerges soon after death and flourishes and evolves as decomposition proceeds.
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 rich in enzymes, and in the brain, which has a high water content. Eventually, though, all other tissues and organs begin to break down in this way. Damaged blood cells begin to 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 contract and relax due to the actions of two filamentous proteins (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.
During these early stages, the cadaveric ecosystem consists mostly of the bacteria that live in and on the living human body. Our bodies host huge numbers of bacteria every one of the body’s surfaces and corners provides a habitat for a specialised microbial community. By far the largest of these communities resides in the gut, which is home to trillions of bacteria of hundreds or perhaps thousands of different species.
The gut microbiome is one of the hottest research topics in biology it’s been linked to roles in human health and a plethora of conditions and diseases, from autism and depression to irritable bowel syndrome and obesity. But we still know little about these microbial passengers. We know even less about what happens to them when we die.
In August 2014, forensic scientist Gulnaz Javan of Alabama State University in Montgomery and her colleagues published the very first study of what they have called the thanatomicrobiome (from thanatos, the Greek word for ‘death’).
“Many of our samples come from criminal cases,” says Javan. “Someone dies by suicide, homicide, drug overdose or traffic accident, and I collect tissue samples from the body. There are ethical issues [because] we need consent.”
Most internal organs are devoid of microbes when we are alive. Soon after death, however, the immune system stops working, leaving them to spread throughout the body freely. This usually begins in the gut, at the junction between the small and large intestines. Left unchecked, our gut bacteria begin to digest the intestines – and then the surrounding tissues – from the inside out, using the chemical cocktail that leaks out of damaged cells as a food source. Then they invade the capillaries of the digestive system and lymph nodes, spreading first to the liver and spleen, then into the heart and brain.
Javan and her team took samples of liver, spleen, brain, heart and blood from 11 cadavers, at between 20 and 240 hours after death. They used two different state-of-the-art DNA sequencing technologies, combined with bioinformatics, to analyse and compare the bacterial content of each sample.
The samples taken from different organs in the same cadaver were very similar to each other but very different from those taken from the same organs in the other bodies. This may be due partly to differences in the composition of the microbiome of each cadaver, or it might be caused by differences in the time elapsed since death. An earlier study of decomposing mice revealed that although the microbiome changes dramatically after death, it does so in a consistent and measurable way. The researchers were able to estimate time of death to within three days of a nearly two-month period.
Javan’s study suggests that this ‘microbial clock’ may be ticking within the decomposing human body, too. It showed that the bacteria reached the liver about 20 hours after death and that it took them at least 58 hours to spread to all the organs from which samples were taken. Thus, after we die, our bacteria may spread through the body in a systematic way, and the timing with which they infiltrate first one internal organ and then another may provide a new way of estimating the amount of time that has elapsed since death.
“After death the composition of the bacteria changes,” says Javan. “They move into the heart, the brain and then the reproductive organs last.” In 2014, Javan and her colleagues secured a US$200,000 grant from the National Science Foundation to investigate further. “We will do next-generation sequencing and bioinformatics to see which organ is best for estimating [time of death] – that’s still unclear,” she says.
One thing that does seem clear, however, is that a different composition of bacteria is associated with different stages of decomposition.
Scattered among the pine trees in Huntsville, Texas, lie around half a dozen human cadavers in various stages of decay. The two most recently placed bodies are spread-eagled near the centre of the small enclosure with much of their loose, grey-blue mottled skin still intact, their ribcages and pelvic bones visible between slowly putrefying flesh. A few metres away lies another, fully skeletonised, with its black, hardened skin clinging to the bones, as if it were wearing a shiny latex suit and skullcap. Further still, beyond other skeletal remains scattered by vultures, lies a third body within a wood and wire cage. It is nearing the end of the death cycle, partly mummified. Several large, brown mushrooms grow from where an abdomen once was.
For most of us the sight of a rotting corpse is at best unsettling and at worst repulsive and frightening, the stuff of nightmares. But this is everyday for the folks at the Southeast Texas Applied Forensic Science Facility. Opened in 2009, the facility is located within a 247-acre area of National Forest owned by Sam Houston State University (SHSU). Within it, a nine-acre plot of densely wooded land has been sealed off from the wider area and further subdivided, by 10-foot-high green wire fences topped with barbed wire.
In late 2011, SHSU researchers Sibyl Bucheli and Aaron Lynne and their colleagues placed two fresh cadavers here, and left them to decay under natural conditions.
Once self-digestion is under way and bacteria have started to escape from the gastrointestinal tract, putrefaction begins. This is molecular death – the breakdown of soft tissues even further, into gases, liquids and salts. It is already under way at the earlier stages of decomposition but really gets going when anaerobic bacteria get in on the act.
Putrefaction is associated with a marked shift from aerobic bacterial species, which require oxygen to grow, to anaerobic ones, which do not. These then feed on the body’s tissues, fermenting the sugars in them to produce gaseous by-products such as methane, hydrogen sulphide and ammonia, which accumulate within the body, inflating (or ‘bloating’) the abdomen and sometimes other body parts.
This causes further discolouration of the body. As damaged blood cells continue to leak from disintegrating vessels, anaerobic bacteria convert haemoglobin molecules, which once carried oxygen around the body, into sulfhaemoglobin. The presence of this molecule in settled blood gives skin the marbled, greenish-black appearance characteristic of a body undergoing active decomposition.
As the gas pressure continues to build up inside the body, it causes blisters to appear all over the skin surface. This is followed by loosening, and then ‘slippage’, of large sheets of skin, which remain barely attached to the deteriorating frame underneath. Eventually, the gases and liquefied tissues purge from the body, usually leaking from the anus and other orifices and frequently also leaking from ripped skin in other parts of the body. Sometimes, the pressure is so great that the abdomen bursts open.
Bloating is often used as a marker for the transition between early and later stages of decomposition, and another recent study shows that this transition is characterised by a distinct shift in the composition of cadaveric bacteria.
Bucheli and Lynne took samples of bacteria from various parts of the bodies at the beginning and the end of the bloat stage. They then extracted bacterial DNA from the samples and sequenced it.
As an entomologist, Bucheli is mainly interested in the insects that colonise cadavers. She regards a cadaver as a specialised habitat for various necrophagous (or ‘dead-eating’) insect species, some of which see out their entire life cycle in, on and around the body.
When a decomposing body starts to purge, it becomes fully exposed to its surroundings. At this stage, the cadaveric ecosystem really comes into its own: a ‘hub’ for microbes, insects and scavengers.
Two species closely linked with decomposition are blowflies and flesh flies (and their larvae). Cadavers give off a foul, sickly-sweet odour, made up of a complex cocktail of volatile compounds that changes as decomposition progresses. Blowflies detect the smell using specialised receptors on their antennae, then land on the cadaver and lay their eggs in orifices and open wounds.
Each fly deposits around 250 eggs that hatch within 24 hours, giving rise to small first-stage maggots. These feed on the rotting flesh and then moult into larger maggots, which feed for several hours before moulting again. After feeding some more, these yet larger, and now fattened, maggots wriggle away from the body. They then pupate and transform into adult flies, and the cycle repeats until there’s nothing left for them to feed on.
Under the right conditions, an actively decaying body will have large numbers of stage-three maggots feeding on it. This ‘maggot mass’ generates a lot of heat, raising the inside temperature by more than 10°C. Like penguins huddling in the South Pole, individual maggots within the mass are constantly on the move. But whereas penguins huddle to keep warm, maggots in the mass move around to stay cool.
“It’s a double-edged sword,” Bucheli explains, surrounded by large toy insects and a collection of Monster High dolls in her SHSU office. “If you’re always at the edge, you might get eaten by a bird, and if you’re always in the centre, you might get cooked. So they’re constantly moving from the centre to the edges and back.”
The presence of flies attracts predators such as skin beetles, mites, ants, wasps and spiders, which then feed on or parasitise the flies’ eggs and larvae. Vultures and other scavengers, as well as other large meat-eating animals, may also descend upon the body.
In the absence of scavengers, though, the maggots are responsible for removal of the soft tissues. As Carl Linnaeus (who devised the system by which scientists name species) noted in 1767, “three flies could consume a horse cadaver as rapidly as a lion”. Third-stage maggots will move away from a cadaver in large numbers, often following the same route. Their activity is so rigorous that their migration paths may be seen after decomposition is finished, as deep furrows in the soil emanating from the cadaver.
Every species that visits a cadaver has a unique repertoire of gut microbes, and different types of soil are likely to harbour distinct bacterial communities – the composition of which is probably determined by factors such as temperature, moisture, and the soil type and texture.
All these microbes mingle and mix within the cadaveric ecosystem. Flies that land on the cadaver will not only deposit their eggs on it, but will also take up some of the bacteria they find there and leave some of their own. And the liquefied tissues seeping out of the body allow the exchange of bacteria between the cadaver and the soil beneath.
When they take samples from cadavers, Bucheli and Lynne detect bacteria originating from the skin on the body and from the flies and scavengers that visit it, as well as from soil. “When a body purges, the gut bacteria start to come out, and we see a greater proportion of them outside the body,” says Lynne.
Thus, every dead body is likely to have a unique microbiological signature, and this signature may change with time according to the exact conditions of the death scene. A better understanding of the composition of these bacterial communities, the relationships between them and how they influence each other as decomposition proceeds could one day help forensics teams learn more about where, when and how a person died.
For instance, detecting DNA sequences known to be unique to a particular organism or soil type in a cadaver could help crime scene investigators link the body of a murder victim to a particular geographical location or narrow down their search for clues even further, perhaps to a specific field within a given area.
“There have been several court cases where forensic entomology has really stood up and provided important pieces of the puzzle,” says Bucheli, adding that she hopes bacteria might provide additional information and could become another tool to refine time-of-death estimates. “I hope that in about five years we can start using bacterial data in trials,” she says.
To this end, researchers are busy cataloguing the bacterial species in and on the human body, and studying how bacterial populations differ between individuals. “I would love to have a dataset from life to death,” says Bucheli. “I would love to meet a donor who’d let me take bacterial samples while they’re alive, through their death process and while they decompose.”
“We’re looking at the purging fluid that comes out of decomposing bodies,” says Daniel Wescott, director of the Forensic Anthropology Center at Texas State University in San Marcos.
Wescott, an anthropologist specialising in skull structure, is using a micro-CT scanner to analyse the microscopic structure of the bones brought back from the body farm. He also collaborates with entomologists and microbiologists – including Javan, who has been busy analysing samples of cadaver soil collected from the San Marcos facility – as well as computer engineers and a pilot, who operate a drone that takes aerial photographs of the facility.
“I was reading an article about drones flying over crop fields, looking at which ones would be best to plant in,” he says. “They were looking at near-infrared, and organically rich soils were a darker colour than the others. I thought if they can do that, then maybe we can pick up these little circles.”
Those “little circles” are cadaver decomposition islands. A decomposing body significantly alters the chemistry of the soil beneath it, causing changes that may persist for years. Purging – the seeping of broken-down materials out of what’s left of the body – releases nutrients into the underlying soil, and maggot migration transfers much of the energy in a body to the wider environment. Eventually, the whole process creates a ‘cadaver decomposition island’, a highly concentrated area of organically rich soil. As well as releasing nutrients into the wider ecosystem, this attracts other organic materials, such as dead insects and faecal matter from larger animals.
According to one estimate, an average human body consists of 50–75 per cent water, and every kilogram of dry body mass eventually releases 32 g of nitrogen, 10 g of phosphorous, 4 g of potassium and 1 g of magnesium into the soil. Initially, it kills off some of the underlying and surrounding vegetation, possibly because of nitrogen toxicity or because of antibiotics found in the body, which are secreted by insect larvae as they feed on the flesh. Ultimately, though, decomposition is beneficial for the surrounding ecosystem.
The microbial biomass within the cadaver decomposition island is greater than in other nearby areas. Nematode worms, associated with decay and drawn to the seeping nutrients, become more abundant, and plant life becomes more diverse. Further research into how decomposing bodies alter the ecology of their surroundings may provide a new way of finding murder victims whose bodies have been buried in shallow graves.
Grave soil analysis may also provide another possible way of estimating time of death. A 2008 study of the biochemical changes that take place in a cadaver decomposition island showed that the soil concentration of lipid-phosphorous leaking from a cadaver peaks at around 40 days after death, whereas those of nitrogen and extractable phosphorous peak at 72 and 100 days, respectively. With a more detailed understanding of these processes, analyses of grave soil biochemistry could one day help forensic researchers to estimate how long ago a body was placed in a hidden grave.
In the relentless dry heat of a Texan summer, a body left to the elements will mummify rather than decompose fully. The skin will quickly lose all of its moisture, so that it remains clinging to the bones when the process is complete.
The speed of the chemical reactions involved doubles with every 10°C rise in temperature, so a cadaver will reach an advanced stage of decomposition after 16 days at an average daily temperature of 25°C. By then, most of the flesh has been removed from the body, and so the mass migration of maggots away from the carcass can begin.
The ancient Egyptians learned inadvertently how the environment affects decomposition. In the predynastic period, before they started building elaborate coffins and tombs, they wrapped their dead in linen and buried them directly in the sand. The heat inhibited the activity of microbes, while burial prevented insects from reaching the bodies, and so they were extremely well preserved. Later on, they began building elaborate tombs for the dead, in order to provide even better for their afterlife, but this had the opposite of the intended effect –separating the body from the sand actually hastened decomposition. And so they invented embalming and mummification.
Embalming involves treating the body with chemicals that slow down the decomposition process. The ancient Egyptian embalmer would first wash the body of the deceased with palm wine and Nile water, remove most of the internal organs through an incision made down the left-hand side, and pack it with natron (a naturally-occurring salt mixture found throughout the Nile Valley). He would use a long hook to pull the brain out through the nostrils, then cover the entire body with natron and leave it to dry for 40 days. Initially, the dried organs were placed into canopic jars that were buried alongside the body later, they were wrapped in linen and returned to the body. Finally, the body itself was wrapped in multiple layers of linen, in preparation for burial. Morticians study the ancient Egyptian embalming method to this day.
Back at the funeral home, Holly Williams performs something similar so that family and friends can view their departed loved one at the funeral as they once were, rather than as they now are. For victims of trauma and violent deaths, this can involve extensive facial reconstruction.
Living in a small town, Williams has worked on many people she knew or grew up with – friends who overdosed, committed suicide or died texting at the wheel. When her mother died four years ago, Williams did some work on her, too, adding the final touches by making up her face: “I always did her hair and make-up when she was alive, so I knew how to do it just right.”
She transfers John to the prep table, removes his clothes and positions him, then takes several small bottles of embalming fluid from a wall cupboard. The fluid contains a mixture of formaldehyde, methanol and other solvents it temporarily preserves the body’s tissues by linking cellular proteins to each other and ‘fixing’ them into place. The fluid kills bacteria and prevents them from breaking down the proteins and using them as a food source.
Williams pours the bottles’ contents into the embalming machine. The fluid comes in an array of colours, each matching a different skin tone. Williams wipes his body with a wet sponge and makes a diagonal incision just above his left collarbone. She ‘raises’ the carotid artery and subclavian vein from the neck, ties them off with pieces of string, then pushes a cannula (thin tube) into the artery and small tweezers into the vein to open up the vessels.
Next, she switches the machine on, pumping embalming fluid into the carotid artery and around John’s body. As the fluid goes in, blood pours out of the incision, flowing down along the guttered edges of the sloped metal table and into a large sink. Meanwhile, she picks up one of his limbs to massage it gently. “It takes about an hour to remove all the blood from an average-sized person and replace it with embalming fluid,” Williams says. “Blood clots can slow it down, so massaging breaks them up and helps the flow of the embalming fluid.”
Once all the blood has been replaced, she pushes an aspirator into John’s abdomen and sucks the fluids out of the body cavity, together with any urine and faeces that might still be in there. Finally, she sews up the incisions, wipes the body down a second time, sets the facial features and re-dresses it. John is now ready for his funeral.
Embalmed bodies do eventually decompose. Exactly when, and how long it takes, depends largely on how the embalming was done, the type of casket in which the body is placed and how it is buried. Bodies are, after all, merely forms of energy, trapped in lumps of matter waiting to be released into the wider universe.
According to the laws of thermodynamics, energy cannot be created or destroyed, only converted from one form to another. In other words: things fall apart, converting their mass to energy while doing so. Decomposition is one final, morbid reminder that all matter in the universe must follow these fundamental laws. It breaks us down, equilibrating our bodily matter with its surroundings, and recycling it so that other living things can put it to use.
Ashes to ashes, dust to dust.
This article first appeared on Mosaic and republished under Creative Commons license. Image by Radu Bercan / Shutterstock .
Symptoms That May Accompany Foamy Urine
In addition to bubbles and foam in the urine, you may notice other symptoms that will indicate which medical condition, if any, is causing the change in the urine output.
Signs to watch for include:
- Extreme fatigue
- Swelling in hands and feet
- Foul-smelling urine
- Dark-colored urine
- Loss of appetite
- Low semen volume after ejaculation
- Lower back pain
Types of Meth Drug Tests (Methamphetamine)
There are several ways in which a person can be tested for methamphetamine. The most common type of test issued is a urine test. Blood testing is also fairly common, but less preferred due to the fact that it is more invasive than urine testing. Other types of testing for meth include: hair testing (which works great to detect usage over a long-term) and saliva testing (which is less invasive than other methods).
Urine tests: Collecting and analyzing fresh urine samples is among the most common ways to test for the presence of methamphetamine (and its metabolites). Urine tests can determine whether someone has used methamphetamine within an approximate period of 1 to 5 days the drug is excreted in urine within 2 to 5 hours of ingestion. For most individuals, methamphetamine is unlikely to show up in urine for longer than 3 days.
However, among chronic long-term users – it may appear within the urine for up to 6 days. It should be noted that urinary pH (acidity vs. alkalinity) can affect results. Since nearly 50% of methamphetamine remains unchanged prior to urinary excretion, it is easily detectable. Furthermore, nearly 10% to 20% of the amphetamine (AMP) metabolite will appear in the urine.
Blood tests: Depending on route of administration, meth can remain in the blood for a period of 1 to 3 days following ingestion. A blood test should detect the presence of methamphetamine within 2 to 4 hours of oral ingestion, several minutes after smoking, and just moments after intravenous injection. Since blood testing doesn’t detect methamphetamine for as long as a urine test, and is more invasive, it isn’t used as often.
Hair tests: While a hair test may not tell us whether a person used meth recently, it can tell us whether an individual has used meth within the past 90 days (3 months). Hair testing typically involves collecting a 3 cm to 6 cm sample of hair, and then analyzing the hair to determine whether the drug is present. Since hair grows at a rate of 1 cm per month, if a person recently used meth for the first time, an immediate hair test wouldn’t show a positive result.
However, if a person used meth today and was hair-tested in 2 months, the test should come back positive. The hair test is considered a highly-accurate form of testing. If conducted by a laboratory with a long (cm) sample of hair, results may accurately detect meth usage over a term longer than 90 days.
Saliva tests: Saliva testing to detect the presence of methamphetamine is rare compared to other testing modalities. That said, a swab of saliva may be collected to accurately determine whether an individual had ingested meth within a 1 to 3 day period. Meth can be detected in saliva in as little as 10 minutes post-ingestion, and usually remains for a period of 48 hours (2 days).
- Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2709797/
- Source: http://www.clinchem.org/content/48/10/1703.full
Bear scat showing consumption of bin bags
The cassowary disperses plant seeds via its feces
Earthworm feces aids in provision of minerals and plant nutrients in an accessible form
The distinctive odor of feces is due to skatole, and thiols (sulfur-containing compounds), as well as amines and carboxylic acids. Skatole is produced from tryptophan via indoleacetic acid. Decarboxylation gives skatole.  
The perceived bad odor of feces has been hypothesized to be a deterrent for humans, as consuming or touching it may result in sickness or infection. 
Feces is discharged through the anus or cloaca during defecation. This process requires pressures that may reach 100 millimetres of mercury (3.9 inHg) (13.3 kPa) in humans and 450 millimetres of mercury (18 inHg) (60 kPa) in penguins.   The forces required to expel the feces is generated through muscular contractions and a build-up of gases inside the gut, prompting the sphincter to relieve the pressure and to release the feces. 
After an animal has digested eaten material, the remains of that material are discharged from its body as waste. Although it is lower in energy than the food from which it is derived, feces may retain a large amount of energy, often 50% of that of the original food.  This means that of all food eaten, a significant amount of energy remains for the decomposers of ecosystems. Many organisms feed on feces, from bacteria to fungi to insects such as dung beetles, who can sense odors from long distances.  Some may specialize in feces, while others may eat other foods. Feces serves not only as a basic food, but also as a supplement to the usual diet of some animals. This process is known as coprophagia, and occurs in various animal species such as young elephants eating the feces of their mothers to gain essential gut flora, or by other animals such as dogs, rabbits, and monkeys.
Feces and urine, which reflect ultraviolet light, are important to raptors such as kestrels, who can see the near ultraviolet and thus find their prey by their middens and territorial markers. 
Seeds also may be found in feces. Animals who eat fruit are known as frugivores. An advantage for a plant in having fruit is that animals will eat the fruit and unknowingly disperse the seed in doing so. This mode of seed dispersal is highly successful, as seeds dispersed around the base of a plant are unlikely to succeed and often are subject to heavy predation. Provided the seed can withstand the pathway through the digestive system, it is not only likely to be far away from the parent plant, but is even provided with its own fertilizer.
Organisms that subsist on dead organic matter or detritus are known as detritivores, and play an important role in ecosystems by recycling organic matter back into a simpler form that plants and other autotrophs may absorb once again. This cycling of matter is known as the biogeochemical cycle. To maintain nutrients in soil it is therefore important that feces returns to the area from which they came, which is not always the case in human society where food may be transported from rural areas to urban populations and then feces disposed of into a river or sea.
Depending on the individual and the circumstances, human beings may defecate several times a day, every day, or once every two or three days. Extensive hardening of the feces that interrupts this routine for several days or more is called constipation.
The appearance of human fecal matter varies according to diet and health.  Normally it is semisolid, with a mucus coating. A combination of bile and bilirubin, which comes from dead red blood cells, gives feces the typical brown color.  
After the meconium, the first stool expelled, a newborn's feces contains only bile, which gives it a yellow-green color. Breast feeding babies expel soft, pale yellowish, and not quite malodorous matter but once the baby begins to eat, and the body starts expelling bilirubin from dead red blood cells, its matter acquires the familiar brown color. 
At different times in their life, human beings will expel feces of different colors and textures. A stool that passes rapidly through the intestines will look greenish lack of bilirubin will make the stool look like clay.
The feces of animals, e.g. guano and manure often are used as fertilizer. 
Dry animal dung is burned and used as a fuel source in many countries around the world. Some animal feces, especially that of camel, bison, and cattle, is a source of fuel when dried. 
Animals such as the giant panda  and zebra  possess gut bacteria capable of producing biofuel. The bacterium in question, Brocadia anammoxidans, can be used to synthesize the rocket fuel hydrazine.  
Coprolites and paleofeces
A coprolite is fossilized feces and is classified as a trace fossil. In paleontology they give evidence about the diet of an animal. They were first described by William Buckland in 1829. Prior to this, they were known as "fossil fir cones" and "bezoar stones". They serve a valuable purpose in paleontology because they provide direct evidence of the predation and diet of extinct organisms.  Coprolites may range in size from a few millimetres to more than 60 centimetres.
Palaeofeces is ancient human feces, often found as part of archaeological excavations or surveys. Intact feces of ancient people may be found in caves in arid climates and in other locations with suitable preservation conditions. These are studied to determine the diet and health of the people who produced them through the analysis of seeds, small bones, and parasite eggs found inside. This feces may contain information about the person excreting the material as well as information about the material. They also may be analyzed chemically for more in-depth information on the individual who excreted them, using lipid analysis and ancient DNA analysis. The success rate of usable DNA extraction is relatively high in paleofeces, making it more reliable than skeletal DNA retrieval. 
The reason this analysis is possible at all is due to the digestive system not being entirely efficient, in the sense that not everything that passes through the digestive system is destroyed. Not all of the surviving material is recognizable, but some of it is. Generally, this material is the best indicator archaeologists can use to determine ancient diets, as no other part of the archaeological record is so direct an indicator. 
A process that preserves feces in a way that they may be analyzed later is called the Maillard reaction. This reaction creates a casing of sugar that preserves the feces from the elements. To extract and analyze the information contained within, researchers generally have to freeze the feces and grind it up into powder for analysis. 
Animal dung occasionally is used as a cement to make adobe mudbrick huts,  or even in throwing sports such as cow pat throwing or camel dung throwing contests. 
Kopi luwak (pronounced [ˈkopi ˈlu.aʔ] ), or civet coffee, is coffee made from coffee berries that have been eaten by and passed through the digestive tract of the Asian palm civet (Paradoxurus hermaphroditus). Giant pandas provide fertilizer for the world's most expensive green tea.  In Malaysia, tea is made from the droppings of stick insects fed on guava leaves.
In northern Thailand, elephants are used to digest coffee beans in order to make Black Ivory coffee, which is among the world's most expensive coffees. 
Dog feces was used in the tanning process of leather during the Victorian era. Collected dog feces, known as "pure", "puer", or "pewer",  was mixed with water to form a substance known as "bate", because proteolytic enzymes in the dog feces helped to relax the fibrous structure of the hide before the final stages of tanning.  Dog feces collectors were known as pure finders. 
Elephants, hippos, koalas and pandas are born with sterile intestines, and require bacteria obtained from eating the feces of their mothers to digest vegetation.
In India, cow dung and cow urine are major ingredients of the traditional Hindu drink Panchagavya. Politician Shankarbhai Vegad said in 2015, "I am witness to it, cow dung and urine are a 100 per cent cure for cancer". 
In the middle east, dung is consumed for a variety of reasons, such as dysentery, a belief of healing properties or as a food staple.
Feces is the scientific terminology, while the term stool is also commonly used in medical contexts.  Outside of scientific contexts, these terms are less common, with the most common layman's term being poo (or poop in North American English). The term shit is also in common use, although is widely considered vulgar or offensive. There are many other terms, see below.
The word faeces is the plural of the Latin word faex meaning "dregs". In most English-language usage, there is no singular form, making the word a plurale tantum  out of various major dictionaries, only one enters variation from plural agreement. 
"Feces" is used more in biology and medicine than in other fields (reflecting science's tradition of classical Latin and New Latin)
- In hunting and tracking, terms such as dung, scat, spoor, and droppings normally are used to refer to non-human animal feces
- In husbandry and farming, manure is common.
- Stool is a common term in reference to human feces. For example, in medicine, to diagnose the presence or absence of a medical condition, a stool sample sometimes is requested for testing purposes. 
- The term bowel movement(s) (with each movement a defecation event) is also common in health care.
There are many synonyms in informal registers for feces, just like there are for urine. Many are euphemismistic, colloquial, or both some are profane (such as shit), whereas most belong chiefly to child-directed speech (such as poo or poop) or to crude humor (such as crap, dump, load and turd.).
Feces of animals
The feces of animals often has special names (some of them are slang), for example:
Quenching Our Thirst
There was a reason I was asking Julio about &ldquohidden&rdquo sources of water, such as vines, that Tsimane' consumed. One evening after dinner a few weeks into my first bout of fieldwork in Bolivia in 2009, the combination of thirst and hunger led me to devour a large papaya. The juices ran down my chin as I ate the ripe fruit. I didn't think much of it at the moment, but soon after I got into my mosquito net for the night, my error revealed itself.
In the Bolivian Amazon, the humidity reaches up to 100 percent at night. Every evening before going to bed I stripped down to my boxers, then rolled my clothes up tightly and put them into large resealable plastic bags so they wouldn't be soaked the next morning. After about an hour of lying in my mosquito net praying for a gust of wind to cool me off, a dreaded sensation set in: I needed to urinate. Knowing the amount of work it would take to get dressed, relieve myself, and then refold and stow my clothes, I cursed my decision to eat the papaya. And I had to repeat the process again later that night. I started thinking about how much water was in that fruit&mdashthe equivalent of three cups, it turns out. No wonder I had to pee.
Our dietary flexibility is perhaps our best defense against dehydration. As I learned the hard way on that sweltering night, the amount of water present in food contributes to total water intake. In the U.S., around 20 percent of the water people ingest comes from food, yet my work among Tsimane' found that foods, including fruits, contribute up to 50 percent of their total water intake. Adults in Japan, who typically drink less water than adults in the U.S., also get around half their water from the foods they eat. Other populations employ different dietary strategies to meet their water needs. Daasanach pastoralists in northern Kenya consume a great deal of milk, which is 87 percent water. They also chew on water-laden roots.
Chimpanzees, our closest living primate relatives, also exhibit dietary and behavioral adaptations to obtaining water. They lick wet rocks and use leaves as sponges to collect water. Primatologist Jill Pruetz of Texas State University has found that in very hot environments, such as the savannas at Fongoli in Senegal, chimps seek shelter in cool caves and forage at night rather than during the day to minimize heat stress and conserve body water. But overall nonhuman primates get most of their water from fruits, leaves and other foods.
Aqueducts brought water from distant springs to the ancient city of Caesarea. Credit: MARIE LISS Getty Images
Humans have evolved to use less water than chimps and other apes, despite our greater sweating ability, as new research by Herman Pontzer of Duke University and his colleagues has shown. Yet our greater reliance on plain water as opposed to water from food means that we must work hard to stay hydrated. Exactly how much water is healthy differs between populations and even from person to person, however. Currently there are two different recommendations for water intake, which includes water from food. The first, from the U.S. National Academy of Medicine, recommends 3.7 liters of water a day for men and 2.7 liters for women, while advising pregnant and lactating women to increase their intake by 300 and 700 milliliters, respectively. The second, from the European Food Safety Authority, recommends 2.5 and 2.0 liters a day for men and women, respectively, with the same increases for pregnant and lactating women. Men need more water than women do because their bodies are larger and have more muscle on average.
These are not hard-and-fast recommendations. They were calculated from population averages based on surveys and studies of people in specific regions. They are intended to fulfill the majority of water needs for moderately active, healthy people living in temperate and often climate-controlled environments. Some people may need more or less water depending on factors that include life habits, climate, activity level and age.
In fact, water intake varies widely even in relatively water-secure locations such as the U.S. Most men consume between 1.2 and 6.3 liters on a given day and women between 1.0 and 5.1 liters. Throughout human evolution our ancestors' water intake probably also varied substantially based on activity level, temperature, and exposure to wind and solar radiation, along with body size and water availability.
Yet it is also the case that two people of similar age and physical condition living in the same environment can consume drastically different amounts of water and both be healthy, at least in the short term. Such variation may relate to early life experiences. Humans undergo a sensitive period during fetal development that influences many physiological functions, among them how our bodies balance water. We receive cues about our nutritional environment while in the womb and during nursing. This information may shape the offspring's water needs.
Experimental studies have demonstrated that water restriction among pregnant rats and sheep leads to critical changes in how their offspring detect bodily dehydration. Offspring born to such water-deprived mothers will be more dehydrated (that is, their urine and blood will be more concentrated) than offspring born to nondeprived mothers before they become thirsty and seek out water. These findings indicate that the dehydration-sensitivity set point is established in the womb.
Thus, the hydration cues received during development may determine when people perceive thirst, as well as how much water they drink later in life. In a sense, these early experiences prepare offspring for the amount of water present in their environment. If a pregnant woman is dealing with a water-scarce environment and is chronically dehydrated, it may lead to her child consistently drinking less water later in life&mdasha trait that is adaptive in places where water is hard to come by. Much more work is needed to test this theory, however.
urine works well for eye infections. I had an eye infection last summer for half a day. Then I remembered about urine therapy. The next morning i collected my mid stream morning pee since the first pee of the day is the strongest most medicinal pee of the day. I dropped several drops into both eyes and immediately i felt the infection going away. The urine did not burn al all. It felt very soothing. About 4 hours later i applied more drops from my jar of morning pee into my eyes and felt the infection clearing up even more. I felt fine and well all day. For the fun of it, i put more urine drops in again at the end of the day just to make sure that i was killing off the infection even though my eyes were already totally cleared up and healthy after the first dose.
I've heard urine works well in the ear for ear infections too. pee on your feet to get rid of atheletes foot. And so many other benefits of urine. When in doubt, try your pee on it. its not going to make your situation any worse, it may cure your ailment and save you some money in the process. be well pee well
Comments for Urine Therapy
I found out about urine therapy 2 weeks ago, and being thoroughly disenchanted with "conventional medicine" already, I navigated pretty quickly through the troll-factory that is the internet and decided to try it. I had drank my own pee within an hour. I've read 4 books on it now, the best one by far being "The Water of Life" by John W. Armstrong.
My experience was that after 4 days of drinking pretty much all the urine I produced, my skin looked better than it has in 5 years. I am 33, female, fighting those inevitable signs of aging, so I was pretty happy when my fine lines were gone in 4 days. The furrow lines between my eyebrows were almost completely gone in 7 days. The deeper horizontal wrinkles across my forehead are faded to about half at 2 weeks. My sun-damaged decollete looks unusually nice, though the hyperpigmentation has not yet faded. I'm hoping for much more skin rejuvenation over the next weeks and months.
The urine therapy clears out my G.I. tract. I'm not sure if everyone gets this, or if my liver is just doing some major spring cleaning. I have had watery BMs about every other day, a couple hours after drinking the first pee (Shivambu, as they call it in Ayurveda). I've done several liver flushes over the years with the Moritz protocol sometimes they cleared out these soft, congealed yellow/green stones, sometimes they didn't. Probably my fault when they didn't because I broke a lot of the rules. Surprisingly, the urine therapy flushed out some of the same yellow stones, without having to do the liver flush protocol. That's nice because I'm bad at following the onerous multi-day instructions for it, and urine therapy is much simpler and gentler.
Strenuous exercise has been easier, and recovery has been a breeze. A bikram yoga class used to leave me sore for 2 days, and the one I did 5 days ago didn't leave me sore at all. My flexibility is up, and the slight tweak in my right knee from over-doing tree pose 2 years ago is gone. I can tree pose so hard now.
I will never go back to not drinking my pee, and I'm sad that it's such a weird therapy because I can't easily tell people about it. But it's called "the secret of secrets" because it's so weird, not because the information hasn't been around. It's not new, it's not forgotten, it's just held at bay by the social stigma of drinking urine.
To those that haven't tried it and are intrigued but hesitant, I noticed that the negative reviews are all from people who haven't done it, so they're just reacting to the weirdness. The positive reviews are all from people who have done it. As a bona-fide 2 week pee-drinker, I say that overcoming the social stigma of drinking urine was the biggest challenge. That first sip was like jumping off a cliff. But I've drank many a beer that is less palatable than my own pee, it turns out.
If it's too embarrassing, just keep it private. This is what I planned to do, but 18 hours in I told my boyfriend (I was bringing a cup into the bathroom and though he'd notice anyway). He was speechless, but after 14 years of dating, he managed not to dump me. Poor guy has had to hear me obsess over it for two weeks now, as he is my only confidante. But today, when I reported to him that the tartar on my gumline softened and I scraped it off with a toothpick, he said he "wants to try it but is hesitant." The benefits are so dramatic and the negative side effects are so non-existant that I'm already trying to figure out how to tell friends and family so they can consider it.
Workplace Substance Abuse Regulations
There are federal and state laws that provide guidelines on the policies employers can set regarding substance abuse in the workplace. Employers can prohibit the use of drugs and alcohol, test for drug use, and fire employees who are engaging in illegal drug use.
However, employees with substance abuse issues are protected by federal and state laws regulating discrimination and disabilities.