Noninfectious Diseases
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Lessons 1 Disease and Disease Prevention
456
2 Hereditary Diseases 3 Metabolic and
460
Nutritional Diseases
462
4 Allergies and Autoimmune Diseases
5 Cancer 6 Chemicals and Poisons 7 Accidents and Injuries
464 466 470 472
Chapter Review
474
Life Skills in Action
476
454 Copyright © by Holt, Rinehart and Winston. All rights reserved.
“
I’m pretty lucky. The most serious I usually get is a
high blood pressure, my cousin has
disease
cold. But my mom has
and
sickle cell
disease.
They both take medicine every day. I’m not sure how they got their diseases, but I hope that I can
”
avoid the diseases.
Health PRE-READING Answer the following multiple-choice questions to find out what you already know about noninfectious diseases. When you’ve finished this chapter, you’ll have the opportunity to change your answers based on what you’ve learned.
1. Noninfectious diseases can be caused by a. viruses. b. bacteria. c. toxins and poisons. d. None of the above
2. Which of the following diseases is caused by an allergy? a. stroke b. eczema c. diabetes d. cancer
3. Smoking cigarettes may cause a. lung cancer. b. heart disease. c. emphysema. d. All of the above
IQ
5. Some metabolic diseases can be treated by a. eating potato chips and candy. b. sleeping a lot. c. taking vitamins once a day. d. eating a special diet.
6. Obesity is related to which of the following conditions? a. high blood pressure b. type 2 diabetes c. heart attack d. all of the above
4. A head injury resulting from an automobile accident may cause a. brain disease. b. a cold. c. a broken leg. d. kidney disease.
7. One way for adults to avoid cancer is to a. have periodic medical checkups. b. read articles about cancer. c. not eat ice cream. d. do breathing exercises. ANSWERS: 1 c; 2 b; 3 d; 4 a; 5 d; 6 d; 7 a
Chapter 18 Copyright © by Holt, Rinehart and Winston. All rights reserved.
Noninfectious Diseases
455
Disease and Disease Prevention
What You’ll Do ■
Explain what a noninfectious disease is.
■
Explain the relationship between risk factors and noninfectious diseases.
■
Identify three strategies for preventing noninfectious diseases.
A car hit Sanjay while he was riding his bicycle. He wasn’t wearing a helmet and had severe head injuries. If Sanjay had worn his helmet, his risk for brain injury would have been reduced by 88 percent. Now, Sanjay’s head injuries may cause permanent brain damage and brain disease.
Noninfectious Diseases and Injuries A disease is any harmful change in the state of health of your body or mind. Diseases may be caused by infections or by a lack of certain nutrients. A disease may result if your immune system is not working normally. Or you may be born with certain diseases. Some diseases result from injuries.
Terms to Learn
• disease • noninfectious disease • risk factor Start Off
Write
How might you get a disease that cannot be passed from person to person?
Diseases are classified as infectious or noninfectious. A noninfectious disease is a disease that is not caused by a virus or a living organism. Noninfectious diseases include immune system disorders, diseases of organs or systems, and nutrition disorders. Diseases produce signs and symptoms. A sign of a disease, such as a fever, is something another person can see or measure. A symptom of a disease, such as a sore throat, is a feeling of pain or discomfort you have when you are sick. Some diseases have several signs and symptoms. And different diseases may produce the same signs and symptoms. But it is possible to have a disease and not have symptoms.
Figure 1 People who have noninfectious diseases can lead active and happy lives.
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Noninfectious Diseases Copyright © by Holt, Rinehart and Winston. All rights reserved.
TABLE 1 Common Noninfectious Diseases Disease
Description
Allergy
an overreaction by the body to something that is harmless to most people, such as pollen or peanuts
Alzheimer’s disease
a brain disorder that gets worse over time and that affects a person’s memory and behavior
Asthma
an abnormal reaction of the respiratory system that causes shortness of breath, wheezing, and coughing
Cancer
a group of diseases that can attack any type of body tissue, in which cell growth is uncontrolled
Circulatory system diseases
a group of diseases that affect the heart and blood vessels, such as hardening of the arteries, high blood pressure, and heart failure
Muscular dystrophy
a group of diseases that cause muscle tissue to get weaker over time
Noninfectious Diseases and Risk Factors Many noninfectious diseases cannot be prevented. Some of them are inherited from parents, and some are present at birth but are not inherited. A person’s age, gender, and, in some cases, race also play a role in some noninfectious diseases. So does diet, or the type and amount of food you eat. All these factors—age, gender, race, and diet—are what doctors call risk factors. A risk factor is a characteristic or behavior that raises a person’s chances of getting a noninfectious disease. You have no control over some risk factors, such as how old you are, whether you are a boy or a girl, and the racial group to which you belong. You cannot change these characteristics. But there are other risk factors, such as how much food you eat, that you can control. And in some cases, the risk factors you can control are the most important ones. For example, lung cancer is one of the leading causes of death in this country. Some lung cancer may be inherited, and some may be caused by poisons in the environment. But the single most common cause of lung cancer is tobacco smoke. Smoking is something you do or don’t do. It is a choice you make. Smoking is a risky behavior, or something you choose to do that increases your chances of getting a noninfectious disease.
Scientists have learned that a wide variety of things in the environment can trigger an asthma attack. These triggers include dust mites, cockroach particles, tobacco smoke, paint fumes, and weather changes. These triggers are risk factors that increase a person’s chances of having an asthma attack.
Even if you could live a risk-free life—and you cannot—you might still have a noninfectious disease. But by making good decisions, such as eating a healthy diet and choosing not to smoke, you can minimize your chances of disease.
Lesson 1 Copyright © by Holt, Rinehart and Winston. All rights reserved.
Disease and Disease Prevention
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Preventing Noninfectious Diseases Scientists, like the one in Figure 2, study diseases to find ways to prevent or cure them. In fact, some noninfectious diseases, such as some cancers, can be prevented. Diseases caused by injuries, especially head and spine injuries, are preventable. Wearing a helmet when you ride your bicycle and wearing a seat belt when you ride in a car will prevent most injury-related diseases.
Figure 2 This scientist is using a scanning electron microscope to study lung cancer cells.
Lung Cancer Cells
Obesity, or weighing at least 20 percent more than your recommended weight, is related to a variety of noninfectious diseases, including type 2 diabetes, heart disease, and high blood pressure. A nutritious diet and regular exercise can help prevent these noninfectious diseases. Most cases of mouth and throat cancer can be prevented if people don’t smoke or chew tobacco. Liver diseases and other diseases can be prevented by not abusing alcohol. So, many noninfectious diseases are preventable.
CAUSE AND EFFECT Suppose you are a physician in a small town. Over a 2-year period, you see a number of patients who have similar symptoms and complaints. Despite all your efforts, you cannot find a disease that matches their symptoms. You know that they all live within 3 miles of an abandoned manufacturing plant, and you know that some of these patients are related to each other.
1. Write a list of questions that you would ask these
2. Make a list of other people you would interview or consult for information.
Analysis 1. Do you think this disease is infectious or noninfectious? Why?
2. Do you think this disease is genetic, related to health behaviors, or caused by something in the environment? Explain your answer.
patients to help you determine the cause of their problems.
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Living with Noninfectious Diseases Most noninfectious diseases cannot be cured, but they can be treated. To treat a disease is to provide medical care to someone who has that disease. Treatment is usually given to control symptoms or to slow or stop the progress of a disease. For example, type 2 diabetes can be treated with medication, exercise, and a healthy diet. Allergies and asthma can usually be controlled with medication. Some heart diseases can be treated with medication, diet, and exercise. Other noninfectious diseases, such as some types of cancer, can be treated with surgery or radiation therapy. Some heart diseases require surgery or medication. Cancer, heart disease, and other noninfectious diseases can be controlled if they are discovered and treated properly. With appropriate medical care, someone who has a noninfectious disease may live a healthy, active life.
MAKING GOOD DECISIONS
Some noninfectious diseases are caused by harmful lifestyle behaviors. List four unhealthy lifestyle behaviors, and then list the alternative healthy lifestyle choices.
Figure 3 If you have high blood pressure, you should have your blood pressure checked frequently. Your doctor will probably take your blood pressure each time you visit.
Using Vocabulary
Critical Thinking
1. What is a noninfectious disease?
4. Making Predictions Poor diet
Understanding Concepts 2. Explain the relationship between risk factors and noninfectious diseases.
3. Describe three strategies for preventing noninfectious diseases.
and too little exercise are risk factors for heart disease. If you eat right and get plenty of exercise, will you never have a heart attack? Explain your answer.
5. Applying Concepts Marcos has a cousin who was born with a damaged heart valve. Should Marcos be afraid of catching his cousin’s heart problem? Explain your answer.
Lesson 1 Copyright © by Holt, Rinehart and Winston. All rights reserved.
www.scilinks.org/health Topic: Noninfectious Diseases HealthLinks code: HD4070
Disease and Disease Prevention
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Hereditary Diseases What You’ll Do ■
■
Describe how genes are related to hereditary diseases. Give three examples of hereditary diseases.
Terms to Learn
Shawn’s father has sickle cell disease. Shawn was tested for the disease when he was born. Fortunately, Shawn did not inherit sickle cell disease. Sickle cell disease causes red blood cells to change shape. These changed cells do not carry oxygen through the body as well as normal red blood cells do. They are more likely to get stuck in blood vessels, which causes painful and dangerous clots.
• hereditary disease
Genes and Hereditary Diseases
Start Off
Sickle cell disease is a hereditary disease. A hereditary disease is a disease caused by defective genes inherited by a child from one or both parents. Hereditary diseases are caused by changes in the structure of genes. Genes control the activities of cells and determine a person’s physical characteristics. Genes are passed from parents to offspring. For example, the color of your eyes is controlled by genes that you inherited from your parents.
Write
What do genes do?
If a gene changes, the change may cause a hereditary disease. For example, in sickle cell disease, a change in a gene causes the change in the shape of the red blood cells. As a result, red blood cells become sickle shaped instead of disk shaped. Some hereditary diseases, such as sickle cell disease, are caused by changes to one gene. Other hereditary diseases, such as breast cancer and colon cancer, may involve changes in more than one gene. And Down syndrome results when a person is born with part or all of an extra chromosome 21.
Figure 4 In cells, genes are found on structures called chromosomes. Humans have 23 pairs of chromosomes.
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▲
Sickle cell disease
▲
Cystic fibrosis
▲
Phenylketonuria (PKU)
▲
Muscular dystrophy
▲
Hemophilia
▲
Tay-Sachs disease
Figure 5 Newborn babies may be tested for a variety of hereditary diseases.
Living with Hereditary Diseases Because doctors are able to test for a number of hereditary diseases, they can often reduce the problems the disease might cause. For example, newborns can be tested for a variety of diseases. One such disease is phenylketonuria (FEN uhl KEET oh NOOR ee uh), or PKU. If untreated, PKU can cause mental retardation. But infants who test positive for PKU are put on a special low-protein diet. The harmful effects of PKU can be prevented if the diet is started right away and is followed throughout life.
Myth: Arthritis affects only older people. Fact: There are several types of arthritis. One type is probably inherited and it affects children. While it is true that the frequency of arthritis increases with age, nearly three out of every five arthritis sufferers are under age 65.
Down syndrome and cystic fibrosis (SIS tik fie BROH sis), or CF, are two other hereditary diseases. People who have these diseases have inherited genetic information that prevents parts of their bodies from functioning normally. People who have CF may have trouble breathing. Down syndrome may affect a person’s ability to learn. People who have hereditary disease may experience medical problems. However, these problems can be reduced if the disease is detected early.
Using Vocabulary
Critical Thinking
1. What is a hereditary disease?
3. Analyzing Ideas Explain the
Understanding Concepts 2. How are genes related to hereditary diseases?
good points and the bad points of knowing about hereditary diseases. Which do you think are more important? Why?
Lesson 2 Copyright © by Holt, Rinehart and Winston. All rights reserved.
www.scilinks.org/health Topic: Inherited Diseases HealthLinks code: HD4062
Hereditary Diseases
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What You’ll Do ■
Describe how metabolism and nutrition are related to disease.
■
Identify two examples of metabolic diseases.
■
List two ways to prevent metabolic diseases.
Terms to Learn
• metabolism Start Off
Write
Why is a healthy diet important in preventing noninfectious diseases?
Metabolic and Nutritional Diseases When Dale was born, the doctor discovered that he had a problem with his metabolism. Now, Dale follows a special diet and leads a normal life. Dale was born with a disease called PKU. People who have PKU are unable to use a certain amino acid found in some foods.
Your Metabolism Most of the time, you do not even think about your metabolism (muh TAB uh LIZ uhm). Metabolism is the process by which the body converts the energy in food into energy the body can use. This process takes place after digestion, when your body metabolizes carbohydrates, protein, fat, vitamins, and minerals. But many things can go wrong with your metabolism. A metabolic disease, such as PKU or diabetes, is one that prevents the body from using one or more nutrients. Some metabolic problems happen before birth and some happen after. Problems may be hereditary, related to nutrition and diet, or have some other cause. In some cases, these problems may be caused by drugs and medication. For example, some hormonal medications may raise blood pressure and cause fat to build up in the blood. Nutrition and diet are important to metabolism. Nutrition is the result of all the processes, including digestion and metabolism, by which your body takes in nutrients in food and uses the nutrients to maintain your health. Poor nutrition and diet may also cause problems. For example, too little vitamin D can cause rickets, a disease that may lead to deformed bones. Too little vitamin A may cause blindness, while too much vitamin A may cause liver disease and hair loss.
Figure 6 Rickets, a metabolic disease caused by too little vitamin D, caused this spine to curve. 462 Copyright © by Holt, Rinehart and Winston. All rights reserved.
Figure 7 This child suffers from malnutrition, which can be especially harmful to children, because their bodies are growing and changing rapidly.
Preventing Nutritional Diseases A nutritious diet is important to have a normal life. A nutritious diet has the proper balance of fat, carbohydrates, protein, vitamins, and minerals. An improper or unhealthy diet may lead to malnutrition, which is poor nourishment caused by a lack of nutrients. Malnutrition, such as too little Vitamin A, may cause disease. But diseases, such as PKU, may also cause malnutrition. Good nutrition and good health are very closely linked. Eating the right amount of food is just as important as eating the right kind of food. If you take in more energy than you use, your body stores the extra energy as fat. Too much stored fat may lead to obesity. Obesity is linked to heart disease, high blood pressure, some types of cancer, type 2 diabetes, and a variety of other diseases.
In your Health Journal, list the food changes you would have to make if you had PKU and could not eat milk, dairy products, meat, fish, chicken, eggs, beans, and nuts.
What can you do to avoid nutritional problems? Eat a nutritious and balanced diet. Avoid excess Calories found in foods such as fried food, large bottles of soda, candy, and cookies. Minimize your time in front of the TV and computer. Don’t eat snacks while you are watching TV. Finally, get some exercise. Spend 20 to 30 minutes a day in vigorous activity of some kind.
Using Vocabulary 1. What is metabolism?
4. What are two ways to prevent metabolic diseases?
Understanding Concepts
Critical Thinking
2. How are metabolism and nutrition
5. Analyzing Ideas How is physical
related to disease?
3. Identify two metabolic diseases.
exercise important in maintaining your metabolism?
Lesson 3 Copyright © by Holt, Rinehart and Winston. All rights reserved.
Metabolic and Nutritional Diseases
463
Allergies and Autoimmune Diseases
What You’ll Do ■
Explain what it means to have an allergy.
■
Describe two ways to treat allergies and autoimmune diseases.
Terms to Learn
• allergy
Every fall, Shari suffers from severe allergies. Shari’s doctor did some tests, and found out that Shari is allergic to tree pollen. When Shari breathes in pollen from certain kinds of trees, her eyes get red and swollen. Her nose gets stuffy. She feels tired. Shari is not alone. Like Shari, many people have allergies.
Being Allergic
• autoimmune disease Start Off
Write
What is the purpose of your immune system?
Shari’s allergy is to tree pollen. But people can be allergic to a wide variety of substances, including strawberries, shellfish, peanuts, cats and dogs, or milk. An allergy is an overreaction of the immune system to something in the environment that is harmless to most people. Something that causes an allergy is an allergen (AL uhr juhn). Almost anything can be an allergen. Your immune system protects your body by responding to invading proteins or other substances. Usually, the proteins are part of harmful bacteria or other microorganisms. If your immune system responds to harmless proteins in pollen, dust, or other allergens, you have an allergy. Normally, your own body cells do not trigger an immune response. Your immune system recognizes the difference between “self” and “not self.” Sometimes, however, immune cells make a mistake. They attack the body cells that they are supposed to protect. Your body reacts as if it is allergic to itself. An autoimmune disease (AWT oh i MYOON di ZEEZ) is a disease in which a person’s immune system attacks certain cells, tissues, or organs of the body.
Figure 8 Eczema is a skin rash caused by a high sensitivity to allergens in the environment.
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Living with Immune Reactions Most allergies and autoimmune reactions cannot be prevented. For one thing, genetics plays a part in both allergies and autoimmune diseases. You cannot change your genetic inheritance. And it is not possible to avoid allergens such as dust and pollen. Therefore, it is not possible to prevent allergies and autoimmune diseases totally. However, treatments for many of these diseases are available. Most allergies and autoimmune diseases are treated with medication. For example, Shari cannot always stay indoors to avoid tree pollen. She will probably take medication to relieve her itchy eyes and stuffy nose. You can take steps to reduce allergy reactions. Always follow your doctor’s advice. Avoid things to which you know you are allergic. Avoid contact with allergens such as peanuts or cats and dogs. Reduce the dust in your house or your room. Treat allergy attacks early, before they get worse.
Myth: Eczema is caused by an emotional disorder.
Fact: Eczema is not caused by an emotional disorder. However, emotional factors such as stress can make eczema worse. Using stress management can reduce stress, anxiety, anger, or frustration and can limit the possibility of an eczema flare-up.
Figure 9 A wide variety of medications is available to treat the symptoms of allergies.
Using Vocabulary
Critical Thinking
1. What is an allergy?
3. Identifying Relationships Maria
Understanding Concepts 2. What are two ways to treat allergies and autoimmune diseases?
Topic: Immune System HealthLinks code: HD4059
thought she was catching colds in September and October, but she realized that she has a runny nose and itchy eyes every fall. What factors should Maria explore to see if she has allergies?
Lesson 4 Copyright © by Holt, Rinehart and Winston. All rights reserved.
www.scilinks.org/health Topic: Asthma HealthLinks code: HD4011
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Cancer What You’ll Do ■
■
Explain how the growth of cancer cells is different from the growth of normal cells. Identify three ways to treat cancer.
Terms to Learn
Cancer is a disease in which cells grow uncontrollably and invade and destroy healthy tissues. But where does cancer come from? Every day, cells in a body die and are replaced. Cell replacement is natural and continuous. This process is controlled by the instructions in DNA. Unfortunately, sometimes the DNA instructions in a cell get changed. Then the cell’s shape, size, and behavior change. The cell’s growth becomes abnormal. It divides and forms more abnormal cells. As these cells grow, they form tumors. A tumor is a mass of abnormal cells.
• tumor • malignant • benign • biopsy Start Off
Write
How do doctors treat cancer?
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Lyndie discovered that breast cancer is the most common kind of cancer among women. Lyndie also learned that because her mom has breast cancer, she is also at risk for getting it.
What Is Cancer?
• cancer
Figure 10 A mole, such as the one shown on the left, is a normal skin growth. If a mole changes color, size, or shape, it may become skin cancer, such as the cells shown on the right.
Lyndie’s mom has just been diagnosed with breast cancer, and Lyndie is worried. Lyndie and her mom talk about breast cancer and look on the Internet to learn more about it.
A tumor may be malignant (muh LIG nuhnt) or benign (bi NIEN). Malignant tumors are cancerous and can be life threatening. Malignant tumor cells spread to other parts of the body. They invade other organs and tissues. And they tend to get worse. Benign tumors are not cancerous and are usually not life threatening. Benign tumor cells do not spread to other organs or tissues.
Normal cells
Cancer cells
Noninfectious Diseases Copyright © by Holt, Rinehart and Winston. All rights reserved.
Common Types of Cancer Cancer can affect any tissue or organ of the body. Some cancers, such as small-cell lung cancer, grow and spread very quickly. Other cancers, such as some skin cancers, grow more slowly. In adult women, the most common types of cancer are breast, ovarian, and lung cancers. In adult men, the most common types of cancer are prostate, colon, and lung cancers. In children, leukemia (loo KEE mee uh) is a common cancer. Leukemia is cancer of the white blood cells, which grow in bone marrow. Skin cancer is one of the most common types of cancer. Most skin cancer is caused by exposure to the ultraviolet (UV) rays in sunlight. UV light changes the DNA in some skin cells, and cancer results. Exposure to UV rays may cause basal cell carcinoma (kar suh NOH muh), the most common type of skin cancer, or melanoma (MEL uh NOH muh), the most serious type of skin cancer. Skin cancer can affect anyone regardless of skin tone.
Figure 11
Basal cell carcinoma (BCC), the most common of all cancers, starts in the bottom of the outer skin layer. BCC usually grows very slowly and can usually be cured. Melanoma also develops in the outer layer of the skin. Melanoma is curable if it is caught early. But if it is not detected, melanoma spreads rapidly to other organs. Once melanoma spreads, it is often fatal.
Types of Cancer
Breast cancer is most often seen in women over 50, but younger women and even men can develop breast cancer.
▲
▲
Colon and rectal (colorectal) cancer—cancer that affects the lower end of the digestive tract—is the second most common cancer in the United States.
Lymphoma (lim FOH muh) is cancer of the cells in the lymph system. It may spread throughout the body and weaken the immune system.
▲
▲
Lung cancer in both men and women is closely linked to cigarette smoking. Lung cancer is the No. 1 cause of deaths due to cancer in the United States.
▲
▲
Skin cancer—the most common type of cancer—is usually caused by too much exposure to sunlight.
Reproductive organ cancers affect both men and women. In men, these cancers strike the testicles and the prostate gland. In women, these cancers strike the ovaries, cervix, and uterus.
▲
Leukemia causes cancerous white blood cells to interfere with production of healthy white blood cells.
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Cancer
467
Diagnosing and Treating Cancer
No Warning Signs Some cancers, such as some types of leukemia, do not show any of the cancer warning signs. Doctors must rely on other tests to detect and diagnose those cancers.
Cancer is often found when a person describes one or more of the cancer warning signs to a doctor. The doctor usually orders a biopsy (BIE OP see) to confirm whether the patient has cancer. A biopsy is a sample of tissue that is removed from the patient and that is sent to a specialist to see if cancer cells are present. If cancer cells are detected, the doctor will order other tests to determine the size and location of the cancer. The doctor and the patient can then plan how to treat the cancer. The following are three major cancer treatments: • Surgery Doctors remove cancer cells from the body. This method works best on cancer that has not spread to other parts of the body. • Chemotherapy (KEE moh THER uh pee) Chemicals are used to destroy cancer cells. This method is used to fight cancers that have spread. • Radiation (RAY dee AY shuhn) High-energy rays from radioactive materials are used to shrink or kill cancer cells. This method is usually used in combination with surgery and chemotherapy.
r bladder habits
hange in bowel o
t heal
sore that does no
r discharge
nusual bleeding o
hickening or lump
anywhere lty swallowing
cu ndigestion or diffi Figure 12 Even though cancer does not usually strike young people, it can. Learn these cancer warning signs.
a wa bvious change in
rt or mole
arseness
o agging cough or h
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Preventing Cancer Some cancer cannot be prevented. It may be caused by hereditary factors, or it may be related to aging or gender. But some cancers are the result of lifestyle choices. In general, men who smoke are 22 times more likely to get lung cancer than men who don’t smoke. And a leading cause of skin cancer is prolonged exposure to sunlight. Other kinds of cancer are caused by alcohol abuse or by exposure to chemicals in the environment. There are ways to reduce your chances of getting cancer. Making healthy choices, such as eating a nutritious diet, not smoking or using alcohol, and using sunscreen, will help you avoid some types of cancer.
PRACTICING WELLNESS
Research skin cancer. Create a public service announcement warning teens about skin cancer and telling them how to avoid it.
You cannot prevent all types of cancer, so early detection is very important. Regular visits to a doctor will help detect cancer early. Your doctor can show you self-exams that may detect cancer in its early stages. The earlier most cancers are detected, the better the chances that they can be treated successfully.
Figure 13 Skin cancer is a common kind of cancer, but the risk of getting skin cancer can be reduced by applying sunblock.
Using Vocabulary
Critical Thinking
1. What is a biopsy?
4. Making Inferences Some kinds of
Understanding Concepts 2. Describe how the growth of cancer cells is different from normal cell growth.
3. What are three ways to treat cancer?
radiation can damage DNA. Why might there be a relationship between radiation and cancer?
5. Analyzing Ideas Why do people who spend a lot of time in the sun have a higher risk of skin cancer than people who spend most of their time indoors?
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Cancer
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Chemicals and Poisons What You’ll Do ■
■
Identify four possible sources of environmental poison. Describe how environmental poisons may cause disease.
Terms to Learn
• poison • toxin Start Off
Write
What do air pollution and cigarette smoke have in common?
Hattie’s lung disease makes it hard for her to breathe. Some days, air pollution makes her disease worse, and she can’t leave home. Air pollution may contain chemicals and tiny particles of soot and dust that irritate Hattie’s lungs. Hattie listens to the weather report each morning to find out whether air pollution will be a problem that day.
Exposure to Environmental Dangers Your environment is all of the living and nonliving things around you. Some parts of the environment may be harmful. For example, natural and manufactured chemicals are all around us. We use chemicals in our home, on our lawns and gardens, and in our industrial processes. Chemicals are necessary and useful. But some of the chemicals we use are poisons. A poison is something that causes illness or death on contact or if it is swallowed or inhaled. Some poisons, such as detergents, are clearly marked. Other poisons, such as the exhaust fumes from cars, are not. Poisons may be solids, liquids, or gases. Some poisons are toxins. A toxin is a poison produced by a living organism. For example, plants such as poison ivy and some mushrooms produce toxins. Some animals, such as certain snakes, bees, and frogs, produce toxins. Bacteria and other microorganisms make toxins that may cause disease.
TABLE 2 Sources of Environmental Dangers Bees, wasps, and other stinging insects are usually relatively harmless, but, for a few people, an insect sting can be life threatening. Many common household chemicals, garden chemicals, and even medicines can cause illness, injury, or death. Water and air pollution, at low levels, can be irritating and relatively harmless. At higher levels, water and air pollution can threaten health and can even be deadly. Poison ivy and its relatives usually cause only an itchy rash that goes away after a few days. Some people, though, are very sensitive, and the rash can cause a serious reaction.
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Figure 14 You are surrounded by a variety of environmental dangers. Learning what the dangers are and how to avoid them will help protect you from diseases caused by these dangers.
Diseases Caused by Environmental Poisons Environmental poisons may cause a wide variety of diseases. For example, air pollution can trigger asthma attacks and other allergic reactions. Air pollution and cigarette smoking can cause a lung disease called emphysema (EM fuh SEE muh). Alcohol, aspirin, and cigarette smoking can cause birth defects. A chemical called vinyl chloride, which is used to make many plastic products, can cause liver cancer or brain tumors. And sometimes infants and children eat paint chips and other things that contain the element lead. Lead is a poison that can damage the brain, kidneys, liver, and other organs. Small amounts of lead may cause behavioral changes and learning problems. Severe lead poisoning may produce convulsions and death.
Allergic asthma affects about 3 million children and 7 million adults in the United States. Despite improvements in air quality in the last 15 years, asthma has increased as an illness and as a cause of death in the United States.
You cannot escape all of the possible poisons in your environment. Learning what the possible dangers are is the best way to avoid them.
Using Vocabulary
Critical Thinking
1. What are toxins? 2. What is the difference between
5. Making Inferences Your brother has a
a poison and a toxin?
Understanding Concepts 3. What are four possible sources of environmental poison?
4. Describe how environmental poisons may cause disease.
summer job mowing and taking care of the grass at a golf course. What are two environmental dangers he should be aware of?
6. Analyzing Ideas “If the dose is big enough, all things are poison.” Do you think this statement is true or false? Explain your answer.
Lesson 6 Copyright © by Holt, Rinehart and Winston. All rights reserved.
Chemicals and Poisons
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Accidents and Injuries Alice was diving at the lake, but she didn’t see the rocks under the surface. She hit the rocks and injured her spinal cord. She could not move her legs.
What You’ll Do ■
Explain how accidents and injuries may cause disease.
■
Identify strategies to prevent accidents and minimize injuries.
Alice was lucky. The damage to her spinal cord was not permanent. After several months, Alice regained the use of her legs and she was able to walk again.
Terms to Learn
Diseases Caused by Injuries
• accident
Accidents are the most common noninfectious medical problem among young people. An accident is any unexpected event that causes damage, injury, or death. Many accidents cause only minor injuries. But accidents may also cause serious injuries, such as Alice’s temporary paralysis, or even death. Accidents usually cause traumatic injuries. A traumatic injury is an injury caused by physical force. Head injuries are a good example.
• traumatic injury Start Off
Write
How can you avoid serious injuries?
Injuries can cause disease. For example, a traumatic head injury can damage the brain. Brain damage can cause several problems, such as seizures, inability to use arms and legs, loss of memory, loss of coordination, loss of speech, and a variety of other symptoms. Most of these problems are the same as those caused by brain tumors and other brain diseases. Accidents
Figure 15 The leading cause of death among young people 10 to 14 years old is unintentional injuries. Many of these deaths could be prevented.
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Deaths per 100,000 children
Leading Causes of Death in Children 10–14 Years Old
Accidents are the leading cause of death among 10to 14-year-olds. In 1999, for instance, accidents were responsible for 39.6 percent of all deaths in this age group.
10 8 6 4 2 0
Unintentional Cancer injuries
Homicide
Suicide
Birth defects
Heart disease
Cause of death Source: Federal Interagency Forum on Child and Family Statistics.
Noninfectious Diseases Copyright © by Holt, Rinehart and Winston. All rights reserved.
Preventing Traumatic Injuries Most accidental injuries are minor. The difference between minor and serious injuries may be small. A few seconds can make a difference to a drowning victim. An inch may mean life or death to a gunshot victim. But many accidents are not beyond your control. In fact, most injuries that teens suffer are preventable. Prevent injury to yourself and others. Make healthy choices about safety. Follow a few simple rules and you can avoid most teen injuries. • Do not drink alcoholic beverages. Alcohol plays a role in a large percentage of automobile and swimming accidents. • Do not play with guns. Learn gun safety. • Always wear a well-fitting helmet and other safety gear when you ride a bicycle or skateboard. • Always wear appropriate and well-fitting safety gear when you play a sport. • Learn CPR. • Wear a seatbelt every time you ride in a car.
Figure 16 Traumatic injuries that may change your life can be prevented or reduced by wearing all the appropriate safety equipment.
Using Vocabulary
Critical Thinking
1. What is an accident? 2. How does a traumatic injury differ
4. Making Good Decisions You want to
from other types of injuries?
Understanding Concepts 3. Explain how accidents and disease are related and how using proper safety equipment may prevent disease.
buy a skateboard. You can’t afford to buy a helmet, too. Should you buy the skateboard anyway? Why or why not?
5. Making Inferences Why is it important to include diseases caused by injuries in a chapter about noninfectious diseases?
Lesson 7 Copyright © by Holt, Rinehart and Winston. All rights reserved.
Accidents and Injuries
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Chapter Summary ■
A noninfectious disease is a disease that is not caused by a virus or living organism. ■ There are several types of noninfectious diseases, including hereditary diseases, nutritional and metabolic diseases, immune system defects, and cancers. ■ Hereditary diseases are caused by a defect in the genes that a person inherits from one or both parents. ■ Metabolic diseases prevent the body from using one or more nutrients. ■ An allergy is an unusual reaction to something in the environment. ■ Cancer can attack any organ of the body. ■ The environment is full of chemicals. Most chemicals are useful, but some are poisonous. ■ Poisons and toxins in the environment cause some noninfectious diseases. ■ Accidents and injuries can cause noninfectious diseases.
Use each of the following terms in a separate sentence: disease, noninfectious disease, hereditary disease, and cancer. For each sentence, fill in the blank with the proper word from the word bank provided below. risk factor allergy autoimmune disease cancer tumor
malignant benign poison toxin traumatic injury
A(n) ___ is a poison produced by a living organism. Sometimes, the physical force of an accident can cause a(n) ___. A ___ is a mass of abnormal cells. If your immune system overreacts to something in the environment, you probably have a(n) ___. A(n) ___ tumor is cancerous and may be life threatening.
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A(n) ___ is a characteristic or behavior that raises your chances of getting a noninfectious disease.
What are three types of noninfectious diseases? Give an example of each type. Explain how good nutrition can help prevent disease. Identify two common causes of cancer, and explain how to minimize the risk of cancer from those causes. How could a traumatic brain injury cause disease? Explain how hereditary diseases are caused by genes. What are three common allergens? Why is it important for people who have inherited risk factors for heart disease to eat a healthy diet and get plenty of exercise?
Review Copyright © by Holt, Rinehart and Winston. All rights reserved.
Making Inferences
Why is it important to know whether a disease is infectious or noninfectious? In some magazines, you see advertisements for vitamin pills that give you hundreds or even thousands of times the daily requirement for some vitamins. Why might taking vitamins in such large doses be dangerous? Imagine that you read in the newspaper a story about a woman who had a tumor the size of a watermelon removed from her abdomen. Doctors estimate that the tumor had been growing for years. Was this tumor likely to have been malignant or benign? Explain your answer.
Arnold has a new skateboard. Maria wants to ride it, but she has no helmet. Maria tells Arnold that she will wear his helmet, which is much too big for her. Should Arnold let Maria try his skateboard anyway? Explain your answer. Use what you have learned in this chapter to set a personal goal. Write your goal, and make an action plan by using the Health Behavior Contract for Noninfectious Diseases. You can find the Health Behavior Contract at go.hrw.com. Just type in the keyword HD4HBC14. Name
Class
Date
Health Behavior Contract
Noninfectious Diseases My Goals: I, ______________________________________, will accomplish one or more of the following goals:
Making Good Decisions
I will practice good health habits that lower my risk of developing diseases such as diabetes, heart disease, emphysema, or lung cancer. I will not use tobacco, alcohol, or other drugs. Other: __________________________________________________________________
In your favorite magazine, you read that certain foods—foods that you like— contain chemicals that increase your risk of having stomach cancer. The risk is fairly small for teens, but increases greatly as a person gets older. Explain how you would decide whether to continue to eat these foods. Imagine that someone has discovered a drug that will increase your metabolism and help you lose weight fast. Unfortunately, the drug has a side effect. Sometimes, but not always, the drug damages the liver and causes heart attacks. Would you take this new diet drug or not? Explain your answer.
My Reasons: By improving my health habits and avoiding tobacco, alcohol, and other drugs, I will keep my body healthy and will lower my risk of disease. Other: __________________________________________________________________
My Values: Personal values that will help me meet my goals are
My Plan: The actions I will take to meet my goals are
Evaluation: I will use my Health Journal to keep a log of actions I took to fulfill this contract. After 1 month, I will evaluate my goals. I will adjust my plan if my goals are not being met. If my goals are being met, I will consider setting additional goals. Signed ________________________________ Date ________________________________
Reading Checkup Take a minute to review your answers to the Health IQ questions at the beginning of this chapter. How has reading this chapter improved your Health IQ?
CHAPTER Chapter XX 18 REVIEW Review Copyright © by Holt, Rinehart and Winston. All rights reserved.
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Assessing Your Health IN ACTION
Assessing your health means evaluating each of the four parts of your health and examining your behaviors. By assessing your health regularly, you will know what your strengths and weaknesses are and will be able to take steps to improve your health. Complete the following activity to improve your ability to assess your health.
Aaron’s Asthma Setting the Scene Aaron has asthma. He knows that too much strenuous exercise may cause him to have asthma attacks. In spite of this, Aaron wants to join the school soccer team. Many of his friends joined the team and Aaron feels left out when they practice after school. Aaron talks to his mother about how not being a part of the team is making him depressed.
4
The
Steps of Assessing Your Health
Guided Practice 1. Choose the part of your health you want to assess. 2. List your strengths and weaknesses. 3. Describe how your behaviors may contribute to your weaknesses. 4. Develop a plan to address your weaknesses.
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Practice with a Friend Form a group of three. Have one person play the role of Aaron and another person play the role of Aaron’s mother. Have the third person be an observer. Walking through each of the four steps of assessing your health, role-play a conversation between Aaron and his mother. Have Aaron assess how his asthma affects the different parts of his health. Have Aaron’s mother support Aaron as he talks about his concerns. The observer will take notes, which will include observations about what the person playing Aaron did well and suggestions of ways to improve. Stop after each step to evaluate the process.
Life Skills in Action Copyright © by Holt, Rinehart and Winston. All rights reserved.
