Module 9 – Elimination
- Demonstrate understanding of normal urination and urinary incontinence
- Demonstrate understanding of catheter care
- Demonstrate understanding of normal bowel elimination and bowel problems
- Demonstrate proper specimen collection
Urination
The urinary system
The urinary system is extremely important to a person’s overall health. It filters the blood, helps humans absorb nutrients, balances fluids, and facilitates the disposal of liquid waste. The urinary system consists of two kidneys, two ureters, the bladder, and the urethra.
Our kidneys are our body’s filters. They filter the blood so it’s free from toxins and waste, and are important for regulating the body’s mineral and electrolyte balance and fluid amount.
Our kidneys are bean-shaped, lay towards the back of our abdomens and are roughly the size of one’s palm.
Kidneys filter out usable material (nutrients, minerals, etc) from liquid waste, which it then turns into urine. Kidneys then send the urine to the bladder through ureters; each kidney has its own ureter, or the tubes that carry urine from the kidneys to the bladder.
Once the urine is in the bladder it remains there until the bladder reaches a certain fullness, when the bladder will tell the brain “I’m full, please pee” and the person develops the urge to urinate.
When the person decides to release their urine then their urinary muscles relaxes and allow urine to pass through to the urethra. The urethra is the tube that runs from the bladder to the meatus, or the external urinary opening. Image by Cancer Research UK, CC BY-SA 4.0 .
Healthy urination
Normal, healthy urine will mostly consist of water. It will be a pale-yellow, although its color can change depending on a person’s hydration, medications, or diet [1] . For instance, someone who eats beets may have a reddish hue to their urine; someone who has recently eaten asparagus may have urine with a pungent smell.
Urine should not be cloudy; healthy urine is clear, with a faint but discernible smell. If the NA notices that a person’s urine is cloudy right upon voiding (another word for urinating) then they should tell the nurse at once. Cloudy urine or urine with particulates indicates the possible presence of infection.
Healthy adults produce about 1500 mL (50 oz) of urine per day, though this amount can vary with age, activity levels, and health.
Urination should be painless, and should contain only urine. If the person’s urine appears to contain blood, mucus, pus, or particulate, the NA should report it to the nurse right away. Also report any strong or foul-smelling urine, painful urination, incontinence, and abnormally frequent urination.
Factors influencing urination
A person usually voids at bedtime, upon waking, and before meals. Others may urinate as frequently as every 2 – 3 hours. Some people can use the bathroom on their own, while others require assistance. NAs must always respond to bathroom requests as quickly as possible. Lots of different factors impact urinary health.
Age : As a person ages, their bladders become less flexible and their capacity diminishes. This means that older adults will need to urinate more often than they did when younger. As a person ages, they also become less likely to completely empty their bladder when voiding, which results in more frequent trips to the bathroom and heightens the person’s risk of infection. NAs should prompt residents to consume fluids and make sure that the person’s bedside water pitcher is always replenished.
If a person’s call light is on, respond as quickly as possible, since it may be a bathroom request. NAs should not expect people to “hold it,” since this is uncomfortable, undignified, and can lead to bladder infections and “accidents.”
Emotions : Stress, anxiety, and depression can all have an impact on a person’s urination. For example, a lack of privacy can lead to altered urination habits. The stress of moving into an assisted living facility and feeling uncomfortable around so many new people may cause someone to urinate more frequently in smaller amounts. Always provide privacy, exercise patience, and make sure that residents know that NAs are there to assist them in a friendly and non-judgmental way.
Thirst : Thirst diminishes as a person ages. If someone is not thirsty then they are less likely to drink, which means that their urinary system may suffer. Maintaining good hydration is necessary for the body’s ability to filter its blood. NAs should encourage people to consume water and other fluids often .
Muscles : As a person ages their muscles weaken and their muscle tone diminishes; good muscle tone is helpful for controlling the flow of urine. NAs can promote the muscular dimension of healthy urination by encouraging ambulation and other forms of exercise. Activity is important both because it helps maintain muscle tone and helps a person become thirsty.
NAs should always respond to requests to use the bathroom as quickly as possible . This is essential for preventing urinary infections. It is also important for keeping a person generally comfortable, and psychologically and emotionally well. Person-centered, holistic care requires attending to a person’s basic needs promptly.
Promptly assisting residents with their bathroom needs closely relates to all three dimensions of the Big Three. How does assisting residents with urination relate to Resident Rights, Infection Control, and Safety? Write for 5 minutes, and discuss your response with a friend or classmate.
Reporting & Recording
Reporting and recording when somebody urinates, the quality of the urine, and any other relevant details will be an important task for NAs. These are some useful vocabulary words for talking and writing about urination [2] :
- Dysuria: painful or difficult urination
- Hematuria: blood in the urine
- Nocturia: frequent urination at night
- Polyuria: voiding abnormally large amounts of urine
- Oliguria: scant amounts of urine, less than 500 mL in 24-hour period
- Urinary incontinence: losing control of one’s bladder
- Urgency: needing to void immediately
- Frequency: urinating often with little time between one voiding and the next
NAs should report and record meticulously. Healthy urination, or lack thereof, can give the care team clues as to what may be wrong with someone. It is also important to address complications with urination quickly, and to include strategies for promoting healthy urination in someone’s care plan.
Pbrundel, CC BY-SA 3.0 ,
Signs of unhealthy urination include:
- swelling in the hands and feet
- painful urination
- changes in the qualities of urine
- changes in frequency or amount of urine
- abdominal swelling
- pain in the bladder area
- urinary incontinence including dribbling
- back pain, which may be related to a kidney disorder
- inadequate fluid intake
If anybody in your care exhibits these symptoms, alert the nurse promptly.
Urinary Disorders
Urinary disorders are common among older adults, and vary in severity. Some especially common disorders of the urinary system include an enlarged prostate, urinary tract infections, kidney infections, kidney stones, and urinary incontinence [3] .
 It involves the enlargement of the prostate gland, located in the groin between the rectum and the base of the penis. When the prostate enlarges it squeezes the urethra and blocks the urine.
Symptoms of an enlarged prostate include:
- a weak stream when urinating
- frequent urination in small amounts
- urgency
- leaking or dribbling
- nocturia
- urinary retention or inability to void
UTIs
Urinary tract infections (UTI) occur when pathogens reproduce along the urinary system. UTIs usually begin when a pathogen enters the body through the urinary opening. UTIs are a common healthcare acquired infection (HAI), and if left untreated can lead to kidney infections and death. If a person experiences symptoms like frequent painful urination, seems confused or disoriented, or has blood in their urine, the NA should alert the nurse immediately.
When they are HAIs, UTIs are usually acquired by the use of catheters, or by bacteria acquired during urological exams. Other causes of healthcare acquired UTIs could be from poor perineal hygiene, immobility, and poor fluid intake.
Meticulous perineal care and proper catheter care are essential to preventing UTIs. A person can also develop a UTI from sexual intercourse. NAs should encourage sexually active residents to urinate shortly after intercourse to help prevent UTIs.
Treatment for UTIs always involves drinking lots of fluids, and may also involve medication.
Kidney disorders
Kidney infection
Pyelonephritis is the medical term for an infection in the kidneys. Kidney infections are serious and can be life-threatening. They are also extremely uncomfortable.
Symptoms of pyelonephritis include:
- chills
- fever
- back pain
- nausea
- vomiting
Since kidney infections can follow UTIs, looking for the symptoms of UTIs can help provide warning signs of a kidney infection. Treatments for kidney infection include powerful antibiotics and increased fluid intake.
Kidney stones
Kidney stones occur when crystals form in the kidneys, creating deposits as small as sand and as large as a golf ball. Some kidney stones will pass through the urinary system on their own, which is a notoriously agonizing process. Others require medical interventions like surgery.
“ Kidney Stone ” by peterjr1961 is licensed under CC BY-NC 2.0 .
Common risk factors for calculi, the medical term for kidney stones, are bedrest, immobility, and poor fluid intake. Kidney stones most commonly occur in people over the age of 40. Symptoms of kidney stones include an intense ongoing pain that becomes worst during urination. Other symptoms include fever, chills, dysuria, and hematuria.
Treatment for kidney stones involves pain medication and increased fluid intake. It may also include straining the person’s urine to see whether the stone passes on its own. If a kidney stone is too large to pass, it may require surgery.
Urinary incontinence
Urinary incontinence occurs in people when they lose control over their bladder. Urinary incontinence can occur due to paralysis, surgery, illness, and other factors. Whatever the reason, NAs must always be respectful and professional when caring for somebody experiencing incontinence.
Many people find experiencing incontinence uncomfortable and embarrassing. A person experiencing incontinence will need empathy, understanding, and reassurance. Maintain a positive attitude and respond promptly to bathroom requests or cleaning needs from residents experiencing incontinence.
Safety is an essential consideration. If somebody is incontinent, they may have an urgent need to relieve themselves; this can make a person who usually needs assistance attempt to get to the bathroom without assistance. NAs should respond to call lights from people experiencing incontinence immediately to avoid a situation where somebody tries to get to the bathroom unassisted, is forced to retain their urine for longer than is comfortable, or risks voiding while in bed.
There are six general kinds of incontinence [5] :
- Stress incontinence : incontinence due to pressure in the abdomen, caused by something like laughing, hiccupping, sneezing, or any action that causes the abdominal muscles to clench.
- Urge incontinence : accidental voiding due to a sudden urge and need to urinate.
- Mixed : incontinence as a combination of stress and urge incontinence
- Functional incontinence : urinating because of a reason other than the urinary tract, such as environmental or cognitive feature. Urinating out of fear would be an example.
- Overflow incontinence : incontinence caused by an overflowing or swollen bladder.
- Reflex incontinence: urine is lost at predicable times when the bladder is full, but the person doesn’t experience the need or urge to void.
The goal of caring for somebody experiencing incontinence is to prevent UTIs, practice infection control and resident rights by addressing wet linens, and to restore the urinary system to proper functioning. Never make somebody feel embarrassed or like a burden because of incontinence – all residents have a right to dignity and respect.
Incontinence can be emotionally taxing. It may impact a person’s dignity and self-esteem, which can lead to social isolation, a diminished sense of independence, and depression. The quality of life of somebody who cannot reliably control when they go to the bathroom will suffer. These feelings will understandably be met with sadness and frustration. Always be kind, courteous, and understanding with people experiencing incontinence.
Caring for somebody experiencing incontinence means NAs are paying close attention to that person’s skin care, particularly in regions that are affected by incontinence episodes. NAs should never let a person sit in wet linens, since this causes skin irritation and can lead to infection.
Always change wet or soiled clothing and linens immediately.
Some people will use incontinence pads or briefs. Incontinence briefs should never be referred to as “diapers;” it is infantilizing, and they are different products. NAs should check incontinence briefs regularly to make sure that a resident always has dry and comfortable garments.
How does each part of the Big Three (Resident Rights, Safety, Infection Control) relate to caring for somebody experiencing urinary incontinence? Write for 5 minutes, then discuss your response with a friend or classmate.
Eliminative care
Assisting with urination
NAs will assist people with toileting every day, multiple times per day. Yet, for something that we know everybody does (eliminating waste), people have different levels of comfort around their body’s waste disposal [6] .
Privacy: When helping somebody with toileting, always provide for the person’s privacy and dignity by shutting the door and closing the person’s privacy screen.
Professionalism : NAs should always be professional and aware of language. Use terms like “elimination,” “voiding,” and “using the bathroom.” Refrain from slang, casual language, and any terminology that could be labeled as crude. Such language can embarrass somebody and make them feel undignified.
Skincare: NAs must provide extra diligent skin care to persons with incontinence, both in general and immediately following an episode of incontinence.
Patience: NAs should always exercise patience when helping somebody with toileting. People are able to use the bathroom at different paces, and some people will take much longer than the NA may initially expect. However much time it takes for somebody to empty their bladder, the NA should remain calm, positive, and encouraging. It is never acceptable to display signs of annoyance or to rush a resident when they are voiding.
Comfort : When assisting the person with urination, NAs should help the person with warmth, privacy, and comfort. The first thing NAs can do to encourage comfortable elimination is to know the person’s patterns and routines when it comes to voiding. NAs can offer the bathroom at regular and predictable intervals, as well as promptly responding to bathroom requests when they occur. If the person is susceptible to chill, the NA can provide warmth by supplying them with a bath blanket to drape over their bare legs while using the toilet.
After helping the person to the toilet, NAs should make sure that the bathroom call light is easily within reach before leaving the bathroom to allow the person some privacy. Once the person has finished in the bathroom, the NA can enter and provide perineal care as needed; if the person is capable of performing their own perineal care after voiding, they should be encouraged to do so. The NA can then assist the person with handwashing, wash their own hands, and then help the person back to their bed or chair.
Portable commodes
NAs will often use portable commodes to assist residents with urination. A portable commode is a kind of chair with a toilet seat, a container under the toilet seat to catch waste, and support for the person’s back and arms. The commode allows for a normal position during elimination, rather than using a bedpan or handheld urinal. Portable commodes will be used for patients who are unable to comfortably make it to the bathroom and back. The container on a commode can be removed and the frame positioned over a standard toilet for added support.
To help somebody use a commode, perform the steps necessary for a wheelchair transfer. If the commode has wheels, they must be locked before initiating the transfer. The NA can then help the person to the commode, and assist them with removing their clothes.
Before leaving the room to allow the person privacy, make sure that the call light is within easy reach. Once the person has finished, the NA can ask them to clean their hands with a sanitary wipe, and then provide perineal care as needed. The NA can then help the person back to their bed or chair.
The container attached to the commode requires cleaning after every elimination. Follow facility policy on the cleaning and storing of commode bins.
NAs must always practice Standard Precautions when helping somebody with elimination. This will always include gloves, and may include gowns and facial PPE depending on the person’s care needs.
Catheter Care
A catheter is a tube inserted into a person’s body to give or take fluids. Urinary catheters remove urine from the bladder and drain it into a drainage bag. Urinary catheters are necessary when a person can’t urinate in the usual way (perhaps they are under anesthesia or on bed rest), or if the person is too weak or disabled to use the urinal, commode, toilet, or bedpan. They are also used to prevent wounds and pressure ulcers from coming into contact with urine, and as a last resort for incontinence.
Urinary catheters are major contributors to healthcare-acquired UTIs. UTIs are extremely painful and dangerous. Urinary catheters are a risk factor for developing UTIs, so they should be avoided to treat incontinence if possible. NAs and caregivers should never use urinary catheters for convenience or because they would prefer not to manage incontinence in other ways.
Types of urinary catheter
There are four common types of urinary catheters; indwelling catheters, condom catheters, straight catheters, and suprapubic catheters [7] .
An indwelling catheter is a tube that is inserted along the whole length of the urethra and into the bladder. A small balloon at the end of the tube in the bladder keeps the tube from coming out. Indwelling catheters remain inserted and are used when people require a catheter for a period of time.
Image by Cancer Research UK, CC BY-SA 4.0
Indwelling catheters use a closed drainage system, which means that nothing can enter the system at any part, from the catheter to the drainage bag. A drainage system consists of a drainage bag to collect the urine and tubing to transport urine from the catheter to the drainage bag.
A drainage bag always hangs from the bedframe, chair, or a wheelchair on the side farthest from the door. Drainage bags must be hung lower than the person’s bladder; if a drainage bag hangs higher than the bladder then urine can flow in the wrong direction back towards the bladder. This creates a heightened risk for UTIs. NAs should never hang a drainage bag on a bed’s guardrails, only ever on the bedframe itself.
Never let the spigot on a drainage bag touch another object when emptying the bag. Allowing the bag’s opening to come into contact with another object could introduce a pathogen, which might then multiply in the drainage bag and make its way into the person’s urethra and bladder by way of the catheter. Practice conscientious infection control measures when handling urinary drainage systems; drainage bags should never touch the floor or another contaminated surface.
A straight catheter is inserted into the bladder through the urethra at regular intervals throughout the day. A straight catheter is removed after each use.
 Condom catheters are external and are not inserted through the urethra.
A suprapubic catheter is inserted into the bladder through a surgical opening in the lower abdomen, above the pubic area. Suprapubic catheters carry less risk of infection, and may be simpler to manage for people who require catheterization long term.
Hygiene
Cleaning catheters is an essential part of practicing infection control. Urinary catheters present a high risk of UTIs; in order to keep residents safe and healthy, the area around their catheter will need to be cleaned regularly, and whenever providing perineal care.
To clean someone’s catheter, perform the opening procedure and practice Standard Precautions. The next step is to gather a basin of warm water and a washcloth. The NA can then have the resident bend their knees and raise their pelvis a few inches from the bed to expose the area for cleaning.
It is important to respect the resident’s dignity and privacy, and only expose the area that is necessary for cleaning. A towel should be placed under the catheter tubing, a bed protector placed between the bed and the person’s buttocks.
Once everything is in place, wet the washcloth and apply soap to it. Gently holding the catheter tubing near the person’s meatus (urinary opening), the clean the four inches of tubing beginning at the meatus and wiping away from it without tugging at the catheter. Wiping away from the meatus, rather than towards it, helps to prevent infection.
Once the area has been cleaned, use a clean washcloth dipped in water to rinse the area, and a third clean washcloth to dry it. Once the area is dry, the NA can dispose of the bed protector and used washcloths, then empty and store the basin.
Drainage bag
To empty the drainage bag, the perform the opening procedure and practice Standard Precautions. Use a graduate and position it under the drainage bag on the floor atop a paper towel. The drainage bag will empty into the graduate once its clamp is opened.
Image by BruceBlaus, CC BY-SA 4.0 ,
After the urine has drained into the graduate, close the drainage bag’s spout and clean it with alcohol wipes. Next the NA should take the graduate full of urine into the bathroom and place it on a flat surface, letting the urine settle before observing the measurement.
Once the measurement is observed, flush the urine, properly clean and store the container, doff PPE, wash hands, and record the amount of urine according to facility protocol.
Drainage bags are emptied and measured either when they are at capacity or at the end of each nursing shift.
 Anybody who cannot get out of bed will use a bedpan for bowel movements, w hile those who cannot urinate into a handheld urinal will also use a bedpan for voiding.
The person will have to lift their hips long enough for the NA to slide the bedpan under them. NAs must always practice Standard Precautions when assisting someone with elimination.
“ Blue Steel Enamelware Bedpan ” by VCU Libraries is licensed under CC BY-NC-SA 2.0 .
For some people, a bedpan may be too tall to lift their pelvis over. A fracture pan is similar to a bedpan except it is only about ½ inch deep on the side that will slide under a person’s buttocks, so it is easier to use for a person with limited mobility. Fracture pans are used for persons in casts, persons with limited back mobility, after a spinal cord injury or back surgery, after a hip fracture, and following a hip replacement surgery.
 NAs should be careful when handling urinals, because they are easy to tip over and if the lid is not securely closed may spill urine. Urinals should never be placed on tables or directly on the bed; they can be placed on the bed rail or on the floor next to the bed. NAs should encourage the person to use the handheld urinal themselves.
Urination equipment should be stored in the bathroom when not in use. If the bathroom is shared, the equipment must be labeled. Bedpans and urinals can also be kept in the bottom section of the person’s bedside stand.
When assisting someone with urination in bed, always use a protective pad. Protective pads help keep bed linens dry and prevent the need to change linens whenever a person uses equipment to urinate from bed. Similarly, a towel or protective pad should be used to transport equipment so no urine dribbles or leaks from the container.
Wash hands (both your own and the residents) multiple times throughout the urination process – before, after, and sometimes during. Make sure to complete the closing procedure.
Bowel Elimination
Digestion
The function of the digestive system to receive food, break it down into the elements it is made of, absorb the usable nutrients, and dispose of what isn’t used. Digestion begins in the mouth with the chewing of food and the application of saliva to chemically break down the food. Once the food is swallowed, peristalsis begins [8] .
BruceBlaus, CC BY-SA 4.0 via Wikimedia Commons
Peristalsis is the contracting motion that the body uses to move food along down the esophagus, into the stomach, and through our intestines. Peristalsis is the reason most humans can swallow while upside down; the contracting motion means that we don’t just have to rely on gravity to keep our sustenance moving along the digestive tract.
The stomach and stomach acid process the chewed and broken-down food into a substance called chyme, which moves along into the intestines where it is either absorbed or becomes waste.
Defecation is the excretion of solid waste once it is processed by the intestines. It is the final stage of the digestive process, and is referred to as bowel elimination. When a person eliminates, they empty their colon of feces, or stool.
Factors influencing bowel movement
Factors like aging, mental and emotional wellbeing, diet, fluid intake, physical activity, and personal routines can all affect a person’s ability to have healthy bowel movements.
Age : As a person ages their body moves food through their GI tract more slowly. The mechanics of chewing become more difficult, less saliva is produced, and the body absorbs fewer nutrients. NAs can promote normal elimination in aging persons by prompting hydration and encouraging nutrient-dense food choices.
Mental and emotional wellbeing : Privacy and disruptions to routine can have a negative impact on bowel elimination.
Always promote privacy and exercise patience when someone is attempting a bowel movement.
When someone is not at home, if they have a roommate for the first time in a while, or factors like anxiety and stress can have a negative impact on bowel movements. The distressing circumstance may make elimination more difficult, produce loose and watery stool, or make somebody need to eliminate urgently.
Diet : Fiber is an important part of a diet conducive to healthy bowel movements, because it helps to hold the stool together. A low-fiber diet can make somebody constipated, and animal fats from dairy, meat, and eggs can also produce constipation. NAs should promote nutritionally dense meals with high quantities of whole grains, fibrous fruits, and vegetables. If the digestive trouble continues, the healthcare team may decide to introduce a probiotic, which is a sample of live bacteria meant to help regulate the body’s digestive system.
Hydration : As a person ages their thirst diminishes, which can result in dehydration and difficult elimination. NAs should prompt residents to drink fluids, and should make sure that their bedside pitcher is always replenished and within reach.
Routines : Personal routines are helpful in maintaining healthy bowel movements. It can be helpful for NAs to prompt residents use attempt a bowel movement at the same time every day; NAs should give residents about 15 – 20 minutes per attempt. Encouraging the resident to consume warm fluids can also stimulate elimination.
People who are on medications that cause constipation may be prescribed laxatives or probiotics to help their bodies manage the digestive side effects of their medication.
Healthy elimination
Stool is usually brown in color, soft, moist, and holds its shape. Stools vary in color depending on the diet of the person, their medications and supplements, or whether they are ill. Stool that is small and hard is difficult to pass and indicates a need for more hydration. Stool that is mostly liquid is called diarrhea, and indicates a need for more fiber or another intervention depending on the cause of the diarrhea [9] .
NAs should observe patients’ stool for any signs of unwellness. Report to the nurse immediately if the resident experience:
- stool that is bloody or discolored
- stool that is hard and dry
- liquid stool
- stool containing discharge such as pus
- the person reports pain when eliminating
Such symptoms indicate a need for further assessment and follow up. When a resident defecates, ask them not to flush until you’ve had a chance to look at their stool.
Common bowel problems
Some common bowel problems include constipation, fecal impaction, flatulence, diarrhea, incontinence, and gastrointestinal bleeding.
Constipation occurs when somebody has difficulty eliminating stool. When somebody is constipated, their body waste moves very slowly through their digestive system, resulting in feces that are hard and dry and difficult to pass.
Constipation may be caused by aging, poor diet, lack of activity, low fluid intake, a nd other factors. If somebody is constipated it can cause gassiness, abdominal discomfort, and irritability.
Image by Click2pharmacy.co.uk Images is licensed under CC BY 2.0
Treatments for constipation start with lifestyle changes in the areas of diet (more fiber), fluid intake (more water), and activity (more exercise). If these less invasive interventions are impossible or ineffective, the doctor may order stool softeners, laxatives, or medication in the form of rectal suppositories.
Fecal impaction is a total inability to pass waste. Feces build up in the rectum. These feces are hard and cause liquid stool to ooze from the anus.
Some symptoms of fecal impaction are abdominal distention (swelling), pain and cramping, and no stool for multiple days.
Fecal impactions cannot be removed by the person on their own, and require a digital exam to diagnose. NAs should report signs of possible fecal impactions immediately. If left untreated, fecal impactions can become extremely severe, resulting in fever, disorientation, and even death. Impactions can be prevented with hydration, exercise, high-fiber foods, and a regular elimination schedule.
Flatulence refers to passing gas, and occurs when gas builds up in the digestive tract and is released. Some flatulence is normal, but excessive flatulence may indicate an intolerance to certain foods, excess dietary fiber, nutrient malabsorption, or irritable bowel syndrome (IBS).
Increased activity levels can help with constipation and flatulence because it promotes digestion, increases thirst, and helps a person stay physically relaxed.
Diarrhea is the frequent passage of liquid stool. Diarrhea is caused by any number of things from dietary disturbances, medications, and illness. Diet changes and drugs are prescribed to harden stool and reduce peristalsis.
NAs will surely care for somebody experiencing diarrhea, likely with some regularity. When caring for somebody with diarrhea, always respond to call lights immediately, since a person may not have much time between realizing they need to go and going. If the person is using assistive equipment to eliminate while in bed, NAs should dispose of stools as quickly as possible.
Diarrhea is highly irritating to skin, and can lead to skin breakdown, pressure ulcers, and infection. Remember to give excellent skin care when a person experiences diarrhea, with special attention to the impacted areas.
Diarrhea contains higher water content than regular feces, which means that a person experiencing diarrhea will lose more water through defecation than they would otherwise. NAs should encourage people experiencing diarrhea to hydrate so they can replace the fluids lost through diarrhea.
Gastrointestinal bleeding is any bleeding along the GI tract. The symptoms of GI bleeding will show up in a person’s stool. Bleeding in the stomach and small intestine causes black or tarry stool. Bleeding in the lower colon and rectum causes red-colored stools. If NAs notice any discoloration in residents’ stool they should report it immediately and record it in the resident’s chart.
Fecal Incontinence
Fecal incontinence is the inability to control the passage of feces through the anus [10] . The involuntary elimination of feces has a negative emotional impact on a person; it can rob a person of independence and personal empowerment. Frustration, sadness, anger, humiliation, and embarrassment are common and understandable responses. NAs must always respond to people experiencing fecal incontinence with kindness, compassion, empathy, and patience.
The causes of incontinence include intestinal disease, nerve damage and injuries, fecal impaction, diarrhea, drugs, illness, dementia or other mental health problems. Other causes of fecal incontinence include not being able to get oneself to the bathroom in a timely manner, not receiving timely assistance with elimination if one requires it, and not being able to locate the bathroom when confused or in a new setting.
The goal treatment for fecal incontinence is to return a person’s bowel control to normal functioning, or as close as possible to normal functioning. Treatment for incontinence may include bowel training, changes in diet, or even surgery.
A person experiencing incontinence may use incontinence briefs and other products to keep their garments and linen clean when they have an uncontrolled bowel movement. NAs should respond to peoples’ call lights right away when they are experiencing incontinence; changing incontinence briefs quickly is essential to maintaining a person’s skin health and overall wellbeing.
All three aspects of the Big Three must be kept in mind while caring for people experiencing incontinence. Residents have a Right to timely care and to dignity, which precludes them being permitted to sit in their own feces. Infection control is paramount, since people with incontinence are more likely to develop skin breakdown and pressure ulcers. Safety matters too, since somebody with incontinence may attempt to get themselves to the bathroom quickly when they really ought to be assisted.
Treatments for fecal incontinence
Bowel training
Bowel training is one tool that a care team can use to help a person experiencing fecal incontinence. The goals of bowel training are to help a person gain control over their bowel movements and to get someone on a regular elimination schedule. Bowel training involves taking the patient to the bathroom at specific times every day. NAs must always follow the care plan carefully and consistently. Recording observations of when a person needs to use the bathroom and the quality of their stool will be an essential part of bowel training.
NAs must always be respectful, kind, and positive, especially when a person experiences an episode of incontinence. Becoming frustrated or angry with somebody when they have an episode of incontinence, or when they take a long time to use the bathroom, is abusive and cannot be tolerated. Additionally, if caregiver reactivity becomes a source of anxiety or worry for somebody experiencing incontinence it can hurt their treatment outcomes. If a NA notices somebody engaging in this type of behavior, they should alert the nurse.
Other factors in someone’s treatment for fecal incontinence may include a high-fiber diet, increased fluids, drinking warm fluids, increased activity levels, and ensuring privacy. Different residents will respond to different things; NA should pay attention to people as individuals to best determine what they need and how they can be helped most effectively.
Suppository
A suppository is a cone-shaped drug that is inserted into a body opening. When a suppository is inserted into the body through the rectum it is called a rectal suppository .
When somebody needs a rectal suppository in order to defecate, a bowel movement will usually occur about 30 minutes after insertion. Doctors may order a rectal suppository to stimulate a bowel movement for persons experiencing constipation, fecal impaction, or to promote a bowel training schedule.
Enema
An enema is a cleansing of the colon with water or another liquid solution to stimulate a bowel movement. NAs are allowed to give enemas in some facilities after they have been trained on the procedure – NAs should always ask further questions if they are unsure about a delegated task. Enemas are given to relieve constipation, impaction, or flatulence. They are also given in preparation for surgery or for the performance of a diagnostic test.
Enemas are either given with tap water, soapsuds, saline, or a prepared commercial solution. For tapwater, saline, and soapsuds enemas, 500 – 1000 mL of water is used, with either no additives, two tea spoons of salt, or 5 mL of castile soap added depending on the type of enema. A commercial enema will be 120 mL of a prescribed solution [11] .
When a tap-water enema is given the enema should not be repeated. However, if a saline or soapsuds enema is ordered the doctor may order that enemas be repeated until the liquid solution is clear and free of stools when it exits the rectum. An enema usually takes about 10 – 20 minutes to perform. The person receiving the enema will be in the left side-lying position throughout.
To give an enema, NAs should make sure they perform the opening procedure, practice Standard Precautions, and communicate with the person throughout the whole process. Once the enema solution is prepared in the IV bag and the person is in position, the NA should lubricate the tip of the tubing before inserting it 2 – 4 inches into the person’s rectum. Do not continue if the person feels pain or if the tubing encounters resistance in the rectum – if this occurs, the NA should tell the nurse immediately.
The solution should be administered slowly and will take 10 – 15 minutes for 750 – 1000 mL of fluid. The temperature of the enema should be roughly body temperature, and must not exceed 105-degrees Fahrenheit. NAs can help the person stay comfortable by encouraging deep and regular breaths, and making light conversation to pass the time. The tube should be clamped and the flow stopped before the bag is empty, so no excess air gets into the bowels.
The person should hold the solution in as long as they can. The NA should make sure the bedpan is immediately available or that the pathway to the person’s bathroom is clear and safe. NAs should make sure to provide proper perineal and skin care following an enema.
Ostomies
Ostomies are surgically created openings in the body that allow for things inside the body to exit through a surgically created path; the tissue surrounding the opening itself is called a stoma. Sometimes a person with an illness that impacts the bowels will require an ostomy to expel waste.
- A colostomy is an ostomy between the colon and the abdominal wall. It allows for the expelling of stool into an ostomy bag. Stool from colostomies will usually be semi-solid. Colostomies can be temporary or permanent; if somebody has their colon removed, they will require a permanent ostomy.
- An ileostomy is an opening made in the small intestines that leads outside the abdominal wall. Stool from an ileostomy will look more liquid and have a somewhat foul smell.
Ostomies use a two-piece system: there is the ostomy pouch, which carries the waste once it is eliminated, and there is the skin barrier that seals the stoma (ostomy opening) from the outside and prevents leaking.
Good skin care is paramount for persons with an ostomy. The stool that ostomies help a body expel is highly irritating to the surrounding skin. NAs should closely observe the area around an ostomy for signs of skin breakdown. The ostomy equipment will be changed every 5 – 7 days.
Collecting Specimens
A specimen is a sample of something like blood, tissue, urine, or feces. Doctors may order a specimen be collected; if the order is for a urine or stool specimen, the task will likely be delegated to the NA. All specimens are labeled with at least 2 forms of ID (name and identification number), as well as the date and time of collection.
Once waste specimens are sealed in their appropriate container, they must also be bagged in a bio-hazard bag. Waste samples are considered highly contaminated, and NAs should wear gloves and practice Standard Precautions while collecting and transporting the sample. If specimens need to be stored before being taken for testing, they will be placed in a specific refrigerator; never place stool or urine specimens in the same refrigerator as food.
Stool specimens
Stool specimens are collected using a device called a hat. Hats, in this context, are cups with wings that sit beneath a toilet seat and catch the stool before in reaches the toilet basin. They look like an upside-down top-hat.
Make sure to let the person know not to mix any urine or toilet paper with the stool sample.
When someone has an order for a stool specimen, the NA should make sure the person lets them know when they are about to have a bowel movement. The NA can then set up the hat on either the toilet or the bedpan, and allow the person privacy to do their business (always practice Standard Precautions throughout).
Once the person has completed their bowel movement, the NA can assist them with cleaning up. After washing hands and with a new pair of gloves, the NA can then then take a wooden tongue blade or disposable spoon and transfer about two tablespoons of stool from the hat to the specimen container and screw the cap closed before placing the specimen container in the biohazard bag for transport.
The wooden tongue blade should be wrapped in a paper towel before being disposed of in the proper bin. The rest of the equipment should then be cleaned and stored in the proper place. The specimen can then be taken to the lab for analysis [12] .
Urine specimens
NAs will collect urine specimens; there are a few different kinds of urine specimens that can give the care team different sorts of information on what is happening in a person’s body [13] .
A routine urine specimen is a specimen that can be collected any time the person urinates. A routine urine specimen is collected using a hat or a bedpan. After performing the opening procedure and getting the supplies ready, the NA should let the person have some privacy. Once they are finished, assist them with perineal care and transfer urine from the hat or bedpan into the specimen collection container before discarding the remaining urine into the toilet.
A fractional urine specimen is collected much the same way that routine urine specimens are collected, except they must be collected within a specified time frame. A routine urine specimen can be collected at any time, but a fractional urine specimen must be collected within the time window specified in the doctor’s order.
A clean catch specimen or a mid-stream specimen is a urine sample that does not include the first or the last urine during voiding. Perineal care is provided before the sample collection.
Set up the specimen collection kit in a similar way to a routine specimen, except the person should void a little bit before the specimen collection begins. Once the person initially voids in the toilet or bedpan, they should pause and let the NA place the specimen collection container beneath their stream. The person can then begin urinating again, and should continue until the specimen container is at least ½ full.
Once an adequate amount of urine has been collected, remove the container and let the person finish voiding. After wiping the urine container with a paper towel and placing it in the biohazard bag, assist with perineal care as needed before making sure they are comfortable and leaving with the sample.
A 24-hour urine specimen is a collection of all the urine voided by a person in a 24-hour period. The collection will usually begin at 7 a.m. and last until 7 a.m. the next day. A person should begin the collection process with an empty bladder, which means the NA should ask them to void right when the collection starts and then discard the first urine. Take care to store and label the urine sample properly as it is it being collected; if any of the sample is mishandled, spilled, or improperly stored, the 24-hour collection window will start over.
When collecting a 24-hour urine sample, perform the opening procedure and check in with the resident. There should be a sign placed on the person’s bedside stand; signs may read something like “24-hour urine specimen collection in process, save all urine.” Once everything is in place, the resident will void once. The NA should mark the amount and exact time of the first voiding, and discard it so it is not included in the sample.
Standard Precautions must be used every time the NA collects urine samples and adds them to the container. The urine from the bedpan, urinal, or hat will be added to the container upon voiding. Store 24-hour specimens according to facility guidelines, usually refrigerated or over ice. Follow instructions closely and always ask follow up questions if unsure about something. Once the 24-hour period is up, add the final void to the container and remove the sign.
Resident Rights and comfort
Having urine and stool specimens collected can make someone feel embarrassed. NAs should always be professional and friendly when collecting specimens, and can make casual conversation to help put the person at ease.
Always explain the procedures clearly and comprehensively to the person, and continue to narrate care as you give it; keeping someone informed about their care in the moment can help calm anxious feelings, and is a good way to practice person-centered care. NAs must always provide privacy, dignity, respect, and autonomy is all aspects of their care, including (perhaps especially) those dealing with a person’s stool and urine.
Key Takeaways
- Healthy urination involves the purposeful voiding of about 1500 mL per day of clear pale-yellow urine. Adequate hydration and activity levels are important for maintaining urinary health. When someone experiences urinary incontinence, it means that they cannot always control when they void and may urinate at times when they do not expect to. Always respond to call lights from incontinent residents as soon as possible.
- When caring for a person with a catheter, begin with a lightly soapy washcloth and clean 4 – 5 inches of catheter tubing beginning at the urinary opening and wiping away from the urinary opening every time. Always wiping away from the urinary opening is an important part of infection control; wiping towards the urinary opening may push pathogens toward the urinary tract, rather than away from it.
- When someone has healthy bowel movements, their stool will be brown and soft, but will still hold its shape. Excessively watery stool is called diarrhea, and stool that is hard and dry can cause constipation. Constipation occurs when someone cannot, or has difficulty attempting to, pass stool. Some common causes of constipation include dehydration, lack of dietary fiber, and age. Fecal incontinence is when someone may eliminate stool uncontrollably; someone experiencing fecal incontinence may use incontinence briefs to manage their symptoms.
- Always practice excellent skin care with incontinent residents. Answer their call lights immediately, and assist with skin and perineal care frequently.
- Follow instructions carefully when collecting a stool or urine sample. Make sure that you follow the correct process for the sample ordered.
Comprehension Questions
1) The function of the kidneys is too …
a. Carry the urine until the person is ready to void
b. Connect to the ureter
c. Filter nutrients and minerals from fluids, and turn the waste into urine
d. Keep the bladder clean
2) What are some qualities of healthy urination?
a. Urine is faintly cloudy
b. Urine is clear and pale yellow in color
c. Producing roughly 500 mL of urine per day
d. Voiding is painless
e. Urination occurs every 30 minutes
3) Respond to the following sentences with T (true) or F (false).
____ Urinary health is impacted by emotional wellbeing.
____ As someone ages they usually develop stronger urinary muscles and better control.
____ Swelling in the hands and feet is a sign that the urinary system is working as it should, especially when the person is being treated for incontinence.
____ One way NAs can help prevent UTIs is by responding to bathroom requests immediately.
____ Oliguria refers to producing abnormally large amounts of urine.
4) How should nursing assistants respond to a resident who has an episode of incontinence?
a. Change any wet linens, clothing, or incontinence briefs immediately
b. Politely suggest that the resident just holds it until a staff member can get there next time
c. Insist to the nurse that the resident use an indwelling catheter
d. Provide perineal and skin care to the impacted area to prevent rashes and skin breakdown
5) What are some practices NAs should use when providing care to someone with a catheter?
a. Place the drainage bag higher than the person so it fills up at the right speed
b. Always use Standard Precaution and excellent infection control measures
c. When providing perineal and catheter care, place a towel beneath the person’s buttocks
d. If the person complains of discomfort, NAs can temporarily remove the catheter to give the person some reprieve
6) What is a bedpan?
a. A pan that residents can use to cook some or all of their meal from bed if they want to. This promotes independence and self-esteem
b. A handheld plastic container residents can urinate into, used for people who cannot get out of bed
c. A device that looks like a container with a toilet seat attached to it, used for people who cannot get out of bed
d. An area under a resident’s bed for storing devices related to elimination
7) Please list at least three signs or symptoms of unhealthy stool that should be reported.
8) If a resident experiences fecal incontinence, which of these elements of their diet may be increased?
a. Milk and yogurt
b. Fowl, such as chicken
c. Fruits and whole grains
d. Coffee
9) Respond to the following sentences with T (true) or F (false).
____ A constipated person usually has diarrhea and uncomfortable defecation.
____ Fecal impactions can be diagnosed by gently feeling for lumps around the person’s anal region; only doctors or nurses can diagnose fecal impaction.
____ Persons experiencing diarrhea should be prompted to hydrate.
____ Enemas cleanse the colon with water or a water solution; NAs may be responsible for administering enemas.
____ Ostomies tend to promote skin health.
10) When collecting a 24-hour urine specimen, NAs should …
a. Collect the first void, record the amount, and include it in the 24-hour total
b. Place a sign by the person’s bed alerting staff that a 24-hour collection is in process
c. Use Standard Precautions
d. Store the urine specimen in a warm and sunny corner of the resident’s room
11) Why is it important that nursing assistants express patience and kindness when residents experience incontinence? Think of your answer in terms of the Big Three. How might a negative caregiver reaction to an episode of incontinence produce negative health outcomes for the resident in the future?
12) A resident’s call light went off once an hour ago, but you were helping another resident finish their meal. By the time you were done, the call light was off and you assumed that another staff member had responded to it. When you go into the first resident’s room, you see that she has soiled herself and has been sitting in urine-soaked sheets for about an hour. When you asked why the call light hadn’t been on, the resident said “Oh, I just didn’t want to bother you and I knew you would get here eventually.” How were the Big Three violated in this situation? How would you respond to the resident in this moment? What could you have done to prevent this situation from occurring?
References
- National Institute on Aging. (2022, January 24). 15 Tips to keep your bladder healthy. https://www.nia.nih.gov/health/15-tips-keep-your-bladder-healthy ↵
- Nursing Assistant, Chapter 11 by Chippewa Valley Technical College is licensed under a Creative Commons Attribution 4.0 International License , except where otherwise noted. ↵
- Dugan, D. (2020). Nursing assisting: A foundation in caregiving (5th ed.), Chapter 16. Hartman. ↵
- Image by Lari Labello is licensed under CC BY 4.0 ↵
- Mayo Clinic. (2023, February 9). Urinary incontinence. Mayoclinic.org. www.mayoclinic.org/diseases-conditions/urinary-incontinence/symptoms-causes/syc-20352808 ↵
- Nursing Assistant, Chapter 5 by Chippewa Valley Technical College is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted. ↵
- MedLine Plus. (n.d.). Urinary catheters. MedLine Plus Medical Encyclopedia. https://medlineplus.gov/ency/article/003981.htm ↵
- Dugan, D. (2020). Nursing assisting: A foundation in caregiving (5th ed.). Chapter 15. Hartman. ↵
- Nursing Assistant, Chapter 11 by Chippewa Valley Technical College is licensed under a Creative Commons Attribution 4.0 International License , except where otherwise noted. ↵
- Sorrentino, S. A., & Remmert, L. N. (2019). Mosby's essentials for nursing assistants (6th ed.), Chapter 22. Elsevier. ↵
- Saga, S., Seim, A., Morkved, S., & Vinsnes, A. G. (n.d.). Bowel problem management among nursing home residents: a mixed methods study. In BMC Nursing. https://doi.org/10.12968 (Reprinted from BMC Nursing, 2014,, 13[35]) ↵
- Sorrentino, S. A., & Remmert, L. N. (2019). Mosby's essentials for nursing assistants (6th ed.), Chapter 26. Elsevier. ↵
- https://www.questdiagnostics.com/healthcare-professionals/test-directory/specimen-handling/urine-collection . ↵


7.10: Conclusion
Bias and discrimination in human sexuality shows itself through normalizing some behaviors and stigmatizing others. We learn sexual scripts as young people about what it looks like to “do” sexuality.  Bodies have been labeled either “overly sexual” or not included as “sexy,” based on prejudice. The constructionist perspective helps us analyze this as something that was created by people to define what sexuality should be. Autonomy over one’s body is something taken for granted, when in fact, there are many in the world who do not have this. The world of humans and their unique sexualities is vast and is worthy of understanding and celebrating. Rather than excluding people from the full range of human possibility, expanding to include the endless possibilities could be transformative.


13.6: Precision Searching
Why Precision Searching?
Effective searching takes precision. This section shows you how to perform several steps to make your searching more precise—you’ll turn up more sources that are useful to you and perhaps, sources that may be even crucial to your research question.
You’ve probably been searching in a more casual way for years and may wonder: Is going to the trouble of precision searching actually worth it?
Yes, definitely, for searches that are important to you! You’re in competition with many people who are working to be as skilled as they can be. So you should use of these steps for course assignments and for information tasks you do on the job. With other tasks and searches, precision searching may be less important.
Search Strategy
This information on precision searching is based on how search tools such as Google and specialized databases operate. If you’ve been more casual in your searching practices, some of these steps may be new to you.
Starting with a research question helps you figure out precisely what you’re looking for. Next, you’ll need the most effective set of search terms – starting from main concepts and then identifying and alternate between related and terms. Those search terms need to be arranged in the most effective way as search statements, which you actually type into a search box.
An important thing to remember is that searching is an iterative process: we try search statements, take a look at what we found and, if the results weren’t good enough, edit our search statements and search again—often multiple times. Most of the time, the first statements we try are not the best, even though Google or another search tool we’re using may give us many results.
It pays to search further for the sources that will help you the most. Be picky.
Here are the steps for an effective search.
Main Concepts
Identify the main concepts in your research question by selecting nouns important to the meaning of your question. Leave out words that don’t help the search, such as adjectives, adverbs, prepositions and, usually, verbs. Nouns that you would use to tag your research question so you could find it later are likely to be its main concepts.
Finding the main concepts in a research question is a lot like finding the main idea in an essay or story. Often the main idea is in the first paragraph, but not always. Sometimes it’s in a later paragraph or even in the conclusion. The same is true with research questions—the main concepts can be at the beginning, middle, or end. Stick to the nouns and only what’s necessary, not already implied. Don’t read in concepts that are not really there. Be alert to words that may have connotations other than the concept you are interested in. For instance, if you identify depression as a main idea, be aware that the search engine won’t automatically know whether you mean depression as a psychological state or as a condition of the economy or as a weather characteristic.
Example: How are birds affected by wind turbines?
The main concepts are birds and wind turbines. Avoid terms like affect (except the noun) and effect as search terms, even when you’re looking for studies that report effects or effectiveness.
Example: What lesson plans are available for teaching fractions?
The main concepts are lesson plans and fractions. Stick to what’s necessary. For instance, don’t include: children—nothing in the research question suggests the lesson plans are for children; teaching—teaching isn’t necessary because lesson plans imply teaching; available—available is not necessary.
Sometimes your research question itself can seem complicated. Make sure you’ve stated the question as precisely as possible (as you learned in Research Questions ). Then apply our advice for identifying main concepts as usual.
EXAMPLE: Does the use of mobile technologies by teachers and students in the classroom distract or enhance the educational experience?
Acceptable main concepts are teaching methods and mobile technology. Another possibility is mobile technologies and education.
Watch out for overly broad terms. For example, don’t include:
- Educational experience (it misses mobile technology).
- Classroom distractions (too broad because there are distractions that have nothing to do with technology).
- Technology (too broad because the question is focused on mobile technology).
Related and Alternative Terms
For each main concept, list alternative terms, including synonyms and singular and plural forms of the words.
Sometimes synonyms, plurals, and singulars aren’t enough. So also consider associations with other words and concepts. For instance, it might help, when looking for information on the common cold, to include the term virus—because a type of virus causes the common cold.
Check to make sure that your terms are not too broad or too narrow for what you want. Figuring out what’s too broad or too narrow takes practice and may differ a bit with each search.
Tip: Try a Thesaurus
Have you considered using a thesaurus, such as thesaurus.com ? Or adding a thesaurus to your browser search bar ?
Activity: Finding Synonyms
When figuring out search terms, you can try your search terms in Visuwords < visuwords.com >, an online graphical dictionary, to see the connections visually in a diagram reminiscent of a neural net. It can help you see connections between terms that are not easy to think of.
Subject Headings Instead of Keywords
All the searches we have talked about so far have been keyword searches, usually used in search engines. But sometimes it pays to use tools—such as library catalogs and journal article databases—that have subject headings that you can search. Subject headings are standardized terms that are assigned by trained experts. (Some such tools also allow keyword searching.) See the section on Specialized Databases for more detail about searching subject headings.
Search Statements
At this point in your search process, you are moving from merely identifying main concepts and similar search terms to developing more complicated search statements that can do more precise searching.
Use Quotation Marks for Phrases
Put quotation marks around any phrases among your terms so that the phrase is what’s searched for, rather than the separate words. “Common cold” instead of common cold is a good example. Without those quotation marks, just think how many sources Google or other search tools would waste their/your time on things that have nothing to do with our sniffles.
Use Wildcard and Truncation Symbols to Broaden
Consider whether using wild card or truncating symbols would help find variations of a word. For instance, the wildcard symbol in wom?n finds both woman and women, and the truncating symbol in mathematic* finds mathematics, mathematically, mathematician, etc.
Consider AND, OR, NOT
You can often do more precise searching by combining search terms by using the words AND, OR, and NOT. These are known as Boolean Operators. Generally, using these operators narrows your search, making it more precise.
AND – If the main idea contains two or more ideas, you’ll want to use AND to combine those terms in your search statement. To look for information about spiders as signs of climate change, you’ll want to have both terms in the search and perform an AND search. That’s what automatically happens in search engines such as Google and Bing unless you tell them to do something different by using OR,NOT, or-.
OR – If the main idea has several synonyms, use OR to combine them. Most search tools search for all terms (AND) by default, so you need to use the operator OR between terms to let them know you want to find any of the terms not documents with all the terms. For instance, in the previous example of Latino small business growth, we would want to also use the term Hispanic.
NOT – If the main idea has a common use you want to exclude, use NOT to exclude that word. For example, if we were looking for information about illegal drug use we would want to exclude prescription drugs from the search results. This is commonly done with NOT or the use of the minus (-) sign. In Google, to exclude a word use-word with no space between the – and the word you want to exclude. If you put a space in there, Google will not exclude the word.(When using some search tools, you have to use AND NOT before the word to exclude it.)
Using Parentheses with Multiple Operators
When a search requires multiple Boolean operators (AND, OR, NOT, or their symbols), you must use parentheses to group the appropriate terms and quotation marks with each Boolean operator. The resulting statements connect terms, remove terms, and organize search terms in ways that result in complex and precise searching.
The use of parentheses may remind you of the mathematical statements written in math courses. The reason parentheses are necessary in searching is that search tools, including Google, generally perform their operations from the left to right of a search statement. If you are using multiple Boolean operators, then the way to make sure that the search is done as a whole statement requires that you use parentheses to combine the sets in your statement.
Never use parentheses unless you are using multiple Boolean operators.
Being skillful at this task of envisioning the effects Boolean operators have on a search can help you troubleshoot your own search statements when they aren’t turning up what you expected.
Example: “United States” AND (immigration or emigration)
Can you tell that the searcher wants to find information about the United States’ immigration or emigration?
The searcher will find more with this arrangement than would turn up if the statement had been “United States” immigration emigration. That’s because the latter arrangement without parentheses would find only information that was about both United States immigration and emigration, instead of either.
Example: (cats OR dogs) AND (treatment OR therapy)
Can you tell that the searcher wants to find information about either treatment or therapy for either cats or dogs?
That’s a different search from what the searcher would have gotten if this statement had been used: cats dogs treatment therapy. Anything found with the latter statement without parentheses would have had to be about both— not just either—therapy and treatment for both—not just either—cats and dogs. So the latter statement would have turned up fewer pieces of information.
Practice with Search
Take some time to practice searching precisely – start by identifying main concepts, then listing related and alternative terms (with the help of wildcard and truncation symbols), and finally constructing search statements.
Activity: Search Practice
This activity focuses on the research question “How does a person’s diet affect the risk for getting cancer?” Work through the three activities below.
Search Terms – Open activity in a web browser.
Truncation – Open activity in a web browser.
Search Statements – Open activity in a web browser.
Activity: More Search Practice
This activity focuses on the research question “What is the effect of gamma radiation on crops?” Work through the three activities below.
More Search Terms – Open activity in a web browser.
More Truncation – Open activity in a web browser.
More Search Statements – Open activity in a web browser.


4.2.1A: The Role of Socialization
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Socialization prepares people for social life by teaching them a group’s shared norms, values, beliefs, and behaviors.
Learning Objectives
- Describe the three goals of socialization and why each is important
Key Points
- Socialization prepares people to participate in a social group by teaching them its norms and expectations.
- Socialization has three primary goals: teaching impulse control and developing a conscience, preparing people to perform certain social roles, and cultivating shared sources of meaning and value.
- Socialization is culturally specific, but this does not mean certain cultures are better or worse than others.
Key Terms
- socialization : The process of learning one’s culture and how to live within it.
- Jeffrey J. Arnett : In his 1995 paper, “Broad and Narrow Socialization: The Family in the Context of a Cultural Theory,” sociologist Jeffrey J. Arnett outlined his interpretation of the three primary goals of socialization.
- norm : A rule that is enforced by members of a community.
The role of socialization is to acquaint individuals with the norms of a given social group or society. It prepares individuals to participate in a group by illustrating the expectations of that group.
Socialization is very important for children, who begin the process at home with family, and continue it at school. They are taught what will be expected of them as they mature and become full members of society. Socialization is also important for adults who join new social groups. Broadly defined, it is the process of transferring norms, values, beliefs, and behaviors to future group members.
Three Goals of Socialization
In his 1995 paper, “Broad and Narrow Socialization: The Family in the Context of a Cultural Theory,” sociologist Jeffrey J. Arnett outlined his interpretation of the three primary goals of socialization. First, socialization teaches impulse control and helps individuals develop a conscience. This first goal is accomplished naturally: as people grow up within a particular society, they pick up on the expectations of those around them and internalize these expectations to moderate their impulses and develop a conscience. Second, socialization teaches individuals how to prepare for and perform certain social roles—occupational roles, gender roles, and the roles of institutions such as marriage and parenthood. Third, socialization cultivates shared sources of meaning and value. Through socialization, people learn to identify what is important and valued within a particular culture.
The term “socialization” refers to a general process, but socialization always takes place in specific contexts. Socialization is culturally specific: people in different cultures are socialized differently, to hold different beliefs and values, and to behave in different ways. Sociologists try to understand socialization, but they do not rank different schemes of socialization as good or bad; they study practices of socialization to determine why people behave the way that they do.


5.1: Power Functions
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A square is cut out of cardboard, with each side having length \(L\). If we wanted to write a function for the area of the square, with \(L\) as the input and the area as output, you may recall that the area of a rectangle can be found by multiplying the length times the width. Since our shape is a square, the length & the width are the same, giving the formula:
\[A(L)=L\cdot L=L^{2}\]
Likewise, if we wanted a function for the volume of a cube with each side having some length \(L\), you may recall volume of a rectangular box can be found by multiplying length by width by height, which are all equal for a cube, giving the formula:
\[V(L)=L\cdot L\cdot L=L^{3}\]
These two functions are examples of power functions , functions that are some power of the variable.
Definition: Power Function
A power function is a function that can be represented in the form
\[f(x)=x^{p}\]
Where the base is a variable and the exponent, \(p\), is a number.
Example \(\PageIndex{1}\)
Which of our toolkit functions are power functions? (This chapter is part of Precalculus: An Investigation of Functions © Lippman & Rasmussen 2017, and contains content remixed with permission from College Algebra © Stitz & Zeager 2013. This material is licensed under a Creative Commons CC-BY-SA license.)
Solutions
The constant and identity functions are power functions, since they can be written as \(f(x)=x^{0}\) and \(f(x)=x^{1}\) respectively.
The quadratic and cubic functions are both power functions with whole number powers: \(f(x)=x^{2}\) and \(f(x)=x^{3}\).
The reciprocal and reciprocal squared functions are both power functions with negative whole number powers since they can be written as \(f(x)=x^{-1}\)and \(f(x)=x^{-2}\).
The square and cube root functions are both power functions with fractional powers since they can be written as \(f(x) = x^{\dfrac{1}{2}}\) or \(f(x) = x^{\dfrac{1}{3}}\)
Exercise \(\PageIndex{1}\)
What point(s) do the toolkit power functions have in common?
- Answer
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(0, 0) and (1, 1) are common to all power functions.
Characteristics of Power Functions
Shown to the right are the graphs of \(f(x)=x^{2}\), \(f(x)=x^{4}\), and \(f(x)=x^{6}\), all even whole number powers. Notice that all these graphs have a fairly similar shape, very similar to the quadratic toolkit, but as the power increases the graphs flatten somewhat near the origin, and become steeper away from the origin.
To describe the behavior as numbers become larger and larger, we use the idea of infinity. The symbol for positive infinity is \(\infty\), and \(-\infty\) for negative infinity. When we say that “\(x\) approaches infinity”, which can be symbolically written as \(x \to \infty\), we are describing a behavior – we are saying that \(x\) is getting large in the positive direction.
With the even power functions, as the \(x\) becomes large in either the positive or negative direction, the output values become very large positive numbers. Equivalently, we could describe this by saying that as \(x\) approaches positive or negative infinity, the \(f(x)\) values approach positive infinity. In symbolic form, we could write: as \(x \to \pm \infty\), \(f(x) \to \infty\).
Shown here are the graphs of \(f(x)=x^{3}\), \(f(x)=x^{5}\), and \(f(x)=x^{7}\), all odd whole number powers. Notice all these graphs look similar to the cubic toolkit, but again as the power increases the graphs flatten near the origin and become steeper away from the origin.
For these odd power functions, as \(x\) approaches negative infinity, \(f(x)\) approaches negative infinity. As \(x\) approaches positive infinity, \(f(x)\) approaches positive infinity. In symbolic form we write: as \(x \to - \infty\), \(f(x) \to - \infty\) and as \(x \to \infty\), \(f(x) \to \infty\).
Definition: long run behavior
The behavior of the graph of a function as the input takes on large negative values,\(x \to - \infty\), and large positive values, \(x \to \infty\), is referred to as the long run behavior of the function.
Example \(\PageIndex{2}\)
Describe the long run behavior of the graph of \(f(x)=x^{8}\).
Solution
Since \(f(x)=x^{8}\) has a whole, even power, we would expect this function to behave somewhat like the quadratic function. As the input gets large positive or negative, we would expect the output to grow without bound in the positive direction. In symbolic form, as \(x \to \pm \infty\), \(f(x) \to \infty\).
Example \(\PageIndex{3}\)
Describe the long run behavior of the graph of \(f(x)=-x^{9}\)
Solution
Since this function has a whole odd power, we would expect it to behave somewhat like the cubic function.  In symbolic form, for the long run behavior we would write: as \(x \to \infty\), \(f(x)\to - \infty\)and as \(x\to - \infty\), \(f(x) \to \infty\).
You may use words or symbols to describe the long run behavior of these functions.
Exercise \(\PageIndex{2}\)
Describe in words and symbols the long run behavior of \(f(x)=-x^{4}\)
- Answer
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As \(x\) approaches positive and negative infinity, \(f(x)\) approaches negative infinity: as \(x \to \pm \infty\), \(f(x) \to -\infty\) because of the vertical flip.
Treatment of the rational and radical forms of power functions will be saved for later.
Polynomials
An oil pipeline bursts in the Gulf of Mexico, causing an oil slick in a roughly circular shape. The slick is currently 24 miles in radius, but that radius is increasing by 8 miles each week. If we wanted to write a formula for the area covered by the oil slick, we could do so by composing two functions together. The first is a formula for the radius, \(r\), of the spill, which depends on the number of weeks, w , that have passed.
Hopefully you recognized that this relationship is linear:
\[r(w)=24+8w\nonumber\]
We can combine this with the formula for the area, \(A\), of a circle:
\[A(r)=\pi r^{2}\nonumber \]
Composing these functions gives a formula for the area in terms of weeks:
\[A(w)=A(r(w))=A(24+8w)=\pi (24+8w)^{2}\nonumber \]
Multiplying this out gives the formula
\[A(w)=576\pi +384\pi w+64\pi w^{2}\nonumber \]
This formula is an example of a polynomial . A polynomial is simply the sum of terms each consisting of a vertically stretched or compressed power function with non-negative whole number power.
terminology of polynomial functions
A polynomial is function that can be written as
\[f(x)=a_{0} +a_{1} x+a_{2} x^{2} +\cdots +a_{n} x^{n} \label{poly1}\]
- Each of the \(a_{i}\) constants are called coefficients and can be positive, negative, or zero, and be whole numbers, decimals, or fractions.
- A term of the polynomial is any one piece of the sum, that is any \(a_{i} x^{i}\). Each individual term is a transformed power function.
- The degree of the polynomial is the highest power of the variable that occurs in the polynomial.
- The leading term is the term containing the highest power of the variable: the term with the highest degree.
- The leading coefficient is the coefficient of the leading term.
Because of the definition of the “leading” term we often rearrange Equation \ref{poly1} so that the powers are descending.
\[f(x)=a_{n} x^{n} +.....+a_{2} x^{2} +a_{1} x+a_{0} \label{poly2}\]
Example \(\PageIndex{4}\)
Identify the degree, leading term, and leading coefficient of these polynomials:
- \(f(x)=3+2x^{2} -4x^{3}\)
- \(g(t)=5t^{5} -2t^{3} +7t\)
- \(h(p)=6p-p^{3} -2\)
Solution
- For the function \(f(x)\), the degree is 3, the highest power on \(x\). The leading term is the term containing that power, \(-4x^{3}\). The leading coefficient is the coefficient of that term, -4.
- For \(g(t)\), the degree is 5, the leading term is \(5t^{5}\), and the leading coefficient is 5.
- For \(h(p)\), the degree is 3, the leading term is \(-p^{3}\), so the leading coefficient is -1.
Definition: long run behavior of polynomials
For any polynomial, the long run behavior of the polynomial will match the long run behavior of the leading term.
Example \(\PageIndex{5}\)
What can we determine about the long run behavior and degree of the equation for the polynomial graphed here?
Solution
Since the output grows large and positive as the inputs grow large and positive, we describe the long run behavior symbolically by writing: as \(x \to \infty\), \(f(x) \to \infty\). Similarly, as \(x \to -\infty\), \(f(x) \to -\infty\).
In words, we could say that as \(x\) values approach infinity, the function values approach infinity, and as \(x\) values approach negative infinity the function values approach negative infinity.
We can tell this graph has the shape of an odd degree power function which has not been reflected, so the degree of the polynomial creating this graph must be odd, and the leading coefficient would be positive.
Exercise \(\PageIndex{3}\)
Given the function\(f(x)=0.2(x-2)(x+1)(x-5)\) use your algebra skills to write the function in standard polynomial form (as a sum of terms) and determine the leading term, degree, and long run behavior of the function.
- Answer
-
The leading term is \(0.2x^{3}\), so it is a degree 3 polynomial.As \(x\) approaches infinity (or gets very large in the positive direction) \(f(x)\) approaches infinity; as \(x\) approaches negative infinity (or gets very large in the negative direction) \(f(x)\) approaches negative infinity. (Basically the long run behavior is the same as the cubic function).
Short Run Behavior
Characteristics of the graph such as vertical and horizontal intercepts and the places the graph changes direction are part of the short run behavior of the polynomial.
Like with all functions, the vertical intercept is where the graph crosses the vertical axis, and occurs when the input value is zero. Since a polynomial is a function, there can only be one vertical intercept, which occurs at the point \((0, a_{0})\). The horizontal intercepts occur at the input values that correspond with an output value of zero. It is possible to have more than one horizontal intercept.
Horizontal intercepts are also called zeros , or roots of the function.
Example \(\PageIndex{6}\)
Given the polynomial function \(f(x)=(x-2)(x+1)(x-4)\), written in factored form for your convenience, determine the vertical and horizontal intercepts.
Solution
The vertical intercept occurs when the input is zero.
\[f(0)=(0-2)(0+1)(0-4)=8\nonumber \]
The graph crosses the vertical axis at the point (0, 8).
The horizontal intercepts occur when the output is zero.
\[0=(x-2)(x+1)(x-4)\nonumber \] when \(x\) = 2, -1, or 4.
\(f(x)\) has zeros, or roots, at \(x\) = 2, -1, and 4.
The graph crosses the horizontal axis at the points (2, 0), (-1, 0), and (4, 0)
Notice that the polynomial in the previous example, which would be degree three if multiplied out, had three horizontal intercepts and two turning points – places where the graph changes direction. We will now make a general statement without justifying it – the reasons will become clear later in this chapter.
intercepts and turning points of polynomials
A polynomial of degree \(n\) will have:
- At most \(n\) horizontal intercepts. An odd degree polynomial will always have at least one.
- At most \(n - 1\) turning points
Example \(\PageIndex{7}\)
What can we conclude about the graph of the polynomial shown here?
Solution
Based on the long run behavior, with the graph becoming large positive on both ends of the graph, we can determine that this is the graph of an even degree polynomial. The graph has 2 horizontal intercepts, suggesting a degree of 2 or greater, and 3 turning points, suggesting a degree of 4 or greater. Based on this, it would be reasonable to conclude that the degree is even and at least 4, so it is probably a fourth degree polynomial.
Exercise \(\PageIndex{4}\)
Given the function\(f(x) = 0.2(x-2)(x+1)(x-5)\), determine the short run behavior.
- Answer
-
Horizontal intercepts are (2, 0) (-1, 0) and (5, 0), the vertical intercept is (0, 2) and there are 2 turns in the graph.
Important Topics of this Section
- Power Functions
- Polynomials
- Coefficients
- Leading coefficient
- Term
- Leading Term
- Degree of a polynomial
- Long run behavior
- Short run behavior


14.7: Standing waves
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As we saw in the last section, when waves have the same frequency, it is possible for them to interfere completely, either destructively or constructively. Waves of the same frequency that interfere can be generated by propagating waves along a string, as the reflected waves from the end of the string will have the same frequency as, and interfere with, the original waves. In general, the resulting wave will be quite complicated, but if you “choose” the frequency (or wavelength) of the generated waves precisely, then the waves will interfere and create a “standing wave”. The standing wave is named this way because it does not appear to propagate along the string. Instead, each point on the string will oscillate with an amplitude that depends on where the point is located along on the string. In contrast, for a traveling wave, all of the points oscillate with the same amplitude.
Three standing waves of different frequencies (wavelengths) are illustrated in Figure \(\PageIndex{1}\).
The solid line in each of the three panels corresponds to one particular snapshot of the standing wave at a particular instant in time. The dashed lines correspond to snapshots at different times. In particular, there is a time where the displacement of all points on the string is zero. Each point on the string vibrates with a different amplitude, which corresponds to the solid line (and the opposite dashed line). Certain points do not oscillate at all; these are called “nodes”. The points at the end of the string are always nodes. Certain points vibrate with a maximal amplitude; these are called “anti-nodes”.
In general, if you pluck a taught string (such as a guitar string), you will create a complicated wave, equivalent to many sine waves with different frequencies, that propagate outwards from the point where the string was plucked. Those sine waves will be reflected by the ends of the string and interfere with each other. Most of the waves will interfere in a complicated way and decay away. Those waves that have the correct frequency to create standing waves will persist on the string for a longer period of time. The string will eventually vibrate as a superposition of the fundamental frequency (the standing wave with one anti-node, also called the first harmonic), and the higher “harmonics” (those standing waves with more anti-nodes).
The wavelength of the fundamental standing wave for a string of length, \(L\) , is given by the condition:
\[\begin{aligned} \lambda = 2L\end{aligned}\]
In general, the \(n\) th harmonic will have a wavelength of:
\[\lambda_{n}=\frac{2L}{n}\quad n=1,2,3,...,\]
The corresponding frequency is give by:
\[f_{n}=\frac{nv}{2L}\]
where \(v=f\lambda\) is the speed of the waves on the string.
A standing wave is the result of two waves of the same frequency and amplitude traveling in opposite directions. Thus, there is no energy that is transmitted by a standing wave (e.g. through the nodes at the end of the string). Although we described standing waves for a string, these are not restricted to one dimensional waves. For example, the membrane of a drum can also support standing waves.
Exercise \(\PageIndex{1}\)
A standing wave (composed of two travelling waves) has a maximum amplitude \(A\) . What must the amplitude \(A_0\) of each travelling wave be?
- \(A_0=1/4 A\)
- \(A_0=1/2 A\)
- \(A_0=A\)
- \(A_0=2A\)
- Answer
- B.
In general, most objects can be characterized by a harmonic (or “resonant”) frequency that corresponds to the standing waves that can exist in the object. If that object is, say, shaken, many waves will propagate through the object and cancel out, except those that have the resonant frequency. Relatively small vibrations, if at the correct frequency, can lead to large standing waves that can result in damage to the object.
Mathematical description of a standing wave
A standing wave is the result of two identical waves, traveling in opposite directions, interfering. Consider the waves described by \(D_1(x,t)\) and \(D_2(x,t)\) that are modeled as follows:
\[\begin{aligned} D_1(x,t) &= A\sin(kx-\omega t)\\[4pt] D_2(x,t) &= A\sin(kx+\omega t)\\[4pt]\end{aligned}\]
These two waves are identical, but travel in opposite directions (due to the sign in front of the \(\omega t\) ). The superposition of these waves is given by:
\[\begin{aligned} D(x,t) &= D_1(x,t) + D_2(x,t)\\[4pt] &=A\Bigr(\sin(kx-\omega t)+\sin(kx+\omega t)\Bigl)\end{aligned}\]
We can use the following trigonometric identity to combine these into a single term:
\[\begin{aligned} \sin\theta_1+\sin\theta_2 = 2\sin\left(\frac{\theta_1+\theta_2}{2} \right) \cos\left( \frac{\theta_1-\theta_2}{2}\right)\end{aligned}\]
The resulting wave is thus given by:
\[\begin{aligned} D(x,t) &= 2A\sin\left(\frac{kx-\omega t + kx+\omega t}{2} \right) \cos\left( \frac{kx-\omega t - kx-\omega t}{2}\right)\\[4pt] &=2A\sin(kx)\cos(\omega t)\end{aligned}\]
If this wave describes the wave on a string of length \(L\) with both ends held fixed, and we set the origin of our coordinate system at one end of the string, then we require that the displacement at \(x=0\) and \(x=L\) is always zero. The first condition is always true, and the second requires that:
\[\begin{aligned} D(x=L,t) &= 0\\[4pt] \sin(kL) &= 0\\[4pt] \therefore kL &= n\pi \quad\quad n=1,2,3,\dots\end{aligned}\]
and \(kL\) must be a multiple of \(2\pi\) . In terms of the wavelength, \(\lambda\) , this gives:
\[\begin{aligned} \frac{2\pi}{\lambda}L &= n\pi\\[4pt] \therefore \lambda&= \frac{2L}{n}\end{aligned}\]
as we argued before, for the wavelength of the \(n\) -th harmonic. The standing wave for the \(n\) -th harmonic is thus described by
\[D(x,t)=2A\sin\left(\frac{n\pi}{L}x \right)\cos (\omega t)\]
A point at position \(x\) will behave like a simple harmonic oscillator and oscillate with an amplitude given by:
\[\begin{aligned} A(x) = 2A\sin\left(\frac{n\pi}{L}x\right)\end{aligned}\]
Each point on the string will vibrate with the same angular frequency, \(\omega\) , but with a different amplitude, depending on their position. For the \(n\) -th harmonic, the nodes of the standing wave are located at:
\[\begin{aligned} \sin\left(\frac{n\pi}{L}x\right) &=0\\[4pt] \frac{n\pi}{L}x &= m\pi \quad\quad m=0,1,2,\dots\\[4pt] \therefore x &= m\frac{L}{n} \end{aligned}\]
Thus, for example, the second node ( \(m=2\) ) of the third harmonic ( \(n=3\) ), is located at \(x=2L/3\) , as can be seen in the bottom panel of Figure \(\PageIndex{1}\). The anti-nodes are located at:
\[\begin{aligned} \frac{n\pi}{L}x &= m\frac{\pi}{2} \quad\quad m=1,3,5,7,\dots\\[4pt] \therefore x&=m\frac{L}{2n}\end{aligned}\]
where, for example, the first anti-node of the first harmonic is located at \(x=L/2\) , as can be seen in the top panel of Figure \(\PageIndex{1}\).
Exercise \(\PageIndex{2}\)
A standing wave on a string (fixed at both ends) has a fundamental frequency \(f\) . If you quadruple the tension in the string, how can you change the length of the string so that the fundamental frequency remains the same?
- half the length.
- double the length.
- triple the length.
- quadruple the length.
- Answer
- B.
Olivia's Thoughts
Olivia Let’s take another look at the equation for a standing wave. In this section, we saw that the equation for a standing wave is given by:
\[\begin{aligned} D(x,t)=2A\sin(kx)\cos(\omega t)\end{aligned}\]
We can rearrange this equation to get:
\[\begin{aligned} D(x,t)=\underbrace{2A\cos(\omega t)}_{\textrm{amplitude}}\sin(kx)\end{aligned}\]
This looks like the equation for a stationary wave (the displacement is a function of \(x\) ) with an amplitude \(2A\cos(\omega t)\) . We know that \(\cos(\omega t)\) will give a value that ranges between -1 and 1, so we can just think of \(\cos(\omega t)\) as a scaling term that modifies the amplitude of the wave.
When we look at a standing wave, this is exactly what we see - a wave whose amplitude is always changing but that does not travel one way or the other. Figure \(\PageIndex{2}\) shows a few snapshots of what the wave looks like at different times.
We can see from the equation that the maximum amplitude will be \(2A\) . This makes sense when we remember that the standing wave is made of two traveling waves of amplitude \(A\) . As these waves move, there will be moments when they completely constructively interfere, which is when the amplitude of the standing wave is maximized. When they completely destructively interfere, the amplitude is zero.


9: Conventional & Sustainable Agriculture
Learning Outcomes
- Describe the components of soils
- Discuss how land use affects global ecosystem conditions
- Identify environmental effects of pesticides
- Recognize the relationship between exposure to POPs and human health
- Explain alternative practices in farming and soil management
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- 9.1: Soil Profiles and Processes
- The word “soil” has been defined differently by different scientific disciplines. In agriculture and horticulture, soil generally refers to the medium for plant growth, typically material within the upper meter or two. Soil consists predominantly of mineral matter, but also contains organic matter (humus) and living organisms. The pore spaces between mineral grains are filled with varying proportions of water and air.
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- 9.2: Soil-Plant Interactions
- Soil plays a key role in plant growth. Beneficial aspects to plants include providing physical support, water, heat, nutrients, and oxygen (Figure 1). Mineral nutrients from the soil can dissolve in water and then become available to plants. Although many aspects of soil are beneficial to plants, excessively high levels of trace metals (either naturally occurring or anthropogenically added) or applied herbicides can be toxic to some plants.
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- 9.3: Conventional Agriculture
- The prevailing agricultural system, variously called “conventional farming,” “modern agriculture,” or “industrial farming,” has delivered tremendous gains in productivity and efficiency. Food production worldwide has risen in the past 50 years; the World Bank estimates that between 70 percent and 90 percent of the recent increases in food production are the result of conventional agriculture rather than greater acreage under cultivation.
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- 9.4: Pests and Pesticides
- Pests are organisms that occur where they are not wanted or that cause damage to crops or humans or other animals. Thus, the term “pest” is a highly subjective term. A pesticide is a term for any substance intended for preventing, destroying, repelling, or mitigating any pest. Though often misunderstood to refer only to insecticides, the term pesticide also applies to herbicides, fungicides, and various other substances used to control pests.
Thumbnail image - Women farmers planting a rice field in West Sumatra.


Page 9.4: Water Treatment
Resolution of the global water pollution crisis requires multiple approaches to improve the quality of our fresh water and move towards sustainability. The most deadly form of water pollution, pathogenic microorganisms that cause waterborne diseases, kills almost 2 million people in underdeveloped countries every year. The best strategy for addressing this problem is proper sewage (wastewater) treatment. Untreated sewage is not only a major cause of pathogenic diseases, but also a major source of other pollutants, including oxygen-demanding waste, nutrients (N and P, particularly), and toxic heavy metals. Wastewater treatment is done at a sewage treatment plant in urban areas and through a septic tank system in rural areas.
The main purpose of sewage (wastewater) treatment is to remove organic matter (oxygen-demanding waste) and kill bacteria. Special methods also can be used to remove nutrients and other pollutants. The numerous steps at a conventional sewage treatment plant include pretreatment (screening and removal of sand and gravel), primary treatment (settling or floatation to remove organic solids, fat, and grease), secondary treatment (aerobic bacterial decomposition of organic solids), tertiary treatment (bacterial decomposition of nutrients and filtration), disinfection (treatment with chlorine, ozone, ultraviolet light, or bleach to kill most microbes), and either discharge to surface waters (usually a local river) or reuse for some other purpose, such as irrigation, habitat preservation, and artificial groundwater recharge (Figure \(\PageIndex{1}\)).
The concentrated organic solid produced during primary and secondary treatment is called sludge , which is treated in a variety of ways including landfill disposal, incineration, use as fertilizer, and anaerobic bacterial decomposition, which is done in the absence of oxygen. Anaerobic decomposition of sludge produces methane gas, which can be used as an energy source. To reduce water pollution problems, separate sewer systems (where street runoff goes to rivers and only wastewater goes to a wastewater treatment plant) are much better than combined sewer systems, which can overflow and release untreated sewage into surface waters during heavy rain. Some cities such as Chicago, Illinois have constructed large underground caverns and also use abandoned rock quarries to hold storm sewer overflow. After the rain stops, the stored water goes to the sewage treatment plant for processing.
Figure \(\PageIndex{1}\). Steps at a Sewage Treatment Plant The numerous processing steps at a conventional sewage treatment plant include pretreatment (screening and removal of sand and gravel), primary treatment (settling or floatation to remove organic solids, fat, and grease), secondary treatment (aerobic bacterial decomposition of organic solids), tertiary treatment (bacterial decomposition of nutrients and filtration), disinfection (treatment with chlorine, ozone, ultraviolet light, or bleach), and either discharge to surface waters (usually a local river) or reuse for some other purpose, such as irrigation, habitat preservation, and artificial groundwater recharge. Source: Leonard G.via WikipediaA septic tank system is an individual sewage treatment system for homes in typically rural settings. The basic components of a septic tank system (Figure \(\PageIndex{2}\)) include a sewer line from the house, a septic tank (a large container where sludge settles to the bottom and microorganisms decompose the organic solids anaerobically), and the drain field (network of perforated pipes where the clarified water seeps into the soil and is further purified by bacteria). Water pollution problems occur if the septic tank malfunctions, which usually occurs when a system is established in the wrong type of soil or maintained poorly.
Figure \(\PageIndex{2}\). Septic System Septic tank system for sewage treatment. Source: United States Geological SurveyFor many developing countries, financial aid is necessary to build adequate sewage treatment facilities. The World Health Organization estimates an estimated cost savings of between $3 and $34 for every $1 invested in clean water delivery and sanitation. The cost savings are from health care savings, gains in work and school productivity, and prevented deaths. Simple and inexpensive techniques for treating water at home include chlorination, filters, and solar disinfection. Another alternative is to use constructed wetlands technology (marshes built to treat contaminated water), which is simpler and cheaper than a conventional sewage treatment plant.
Bottled water is not a sustainable solution to the water crisis. Bottled water is not necessarily any safer than the U.S. public water supply, it costs on average about 700 times more than U.S. tap water, and every year it uses approximately 200 billion plastic and glass bottles that have a relatively low rate of recycling. Compared to tap water, it uses much more energy, mainly in bottle manufacturing and long-distance transportation. If you don’t like the taste of your tap water, then please use a water filter instead of bottled water!
CLEAN WATER ACT
Figure \(\PageIndex{3}\). Cuyahoga River on fire. Source: National Oceanic and Atmospheric AdministrationDuring the early 1900s rapid industrialization in the U.S. resulted in widespread water pollution due to free discharge of waste into surface waters. The Cuyahoga River in northeast Ohio caught fire numerous times, including a famous fire in 1969 that caught the nation’s attention. In 1972 Congress passed one of the most important environmental laws in U.S. history, the Federal Water Pollution Control Act, which is more commonly called the Clean Water Act . The purpose of the Clean Water Act and later amendments is to maintain and restore water quality, or in simpler terms to make our water swimmable and fishable. It became illegal to dump pollution into surface water unless there was formal permission and U.S. water quality improved significantly as a result. More progress is needed because currently the EPA considers over 40,000 U.S. water bodies as impaired, most commonly due to pathogens, metals, plant nutrients, and oxygen depletion. Another concern is protecting groundwater quality, which is not yet addressed sufficiently by federal law.
Contributors and Attributions
- Essentials of Environmental Science by Kamala Doršner is licensed under CC BY 4.0. Modified from the original by Matthew R. Fisher.