Waterborne Illnesses
Description
In America, most people take clean, safe drinking water for granted. In many countries of the world, available fresh water carries a variety of disease agents. In this unit, students will learn about how water becomes impure with parasites and other contaminants; they will read personal accounts of unsafe water; and they'll work together to brainstorm solutions to the water problems of communities in Africa. This unit was prepared in collaboration with the Office of Ground Water and Drinking Water at the Environmental Protection Agency.
Time Frame
Five to ten 45-minute class periods depending on teacher choice
Curricular Areas
Health, geography
Grades
10–12
Essential Questions
How can natural resources affect health?
Do all cultures look at resources in the same way?
Materials
Internet access
Poster board, markers, glue
“Decision Process for Drinking Water" (pdf–50 KB)
“Water Pollution Prevention and Conservation" (pdf–44 KB) and the supplies listed in this experiment
“Water Treatment Path"
“Water Filtration"
Vignettes about health and sanitation from Water in Africa website link to resources section
Health and nutrition stories by Peace Corps Volunteers serving in Africa (PDF or RTF)
Evaluation Rubric (PDF or RTF).
Standards
Health Standard 2—Knows environmental and external factors that affect individual and community health
Benchmark—Knows how personal health can be influenced by society (e.g., culture) and science (e.g., technology)
Benchmark—Knows how individuals can improve or maintain community health (e.g., becoming active in environmental and economic issues that affect health, assisting in the development of public health policies and laws, exercising voting privileges)
Health Standard 8—Knows essential concepts about the prevention and control of disease
Benchmark—Understands the social, economic, and political effects of disease on individuals, families, and communities
Geography Standard 6—Understands that culture and experience influence people's perceptions of places and regions
Benchmark—
Understands how individuals view places and regions on the basis of their stage of life, sex, social class, ethnicity, values, and belief systems
Benchmark—Knows ways in which people's changing views of places and regions reflect cultural change
National Science Education Standards—Content Standard F: Science in Personal and Social Perspectives
Objectives
At the end of a one-week lesson, students will be able to
- Identify common waterborne illnesses, and their symptoms, prevention, and treatment.
- Understand how cultural traditions can make prevention of illness difficult.
Procedure
Day 1
1. Talk to the class in general about waterborne illnesses. Ask if anyone in the class has ever become sick from drinking unclean water. (Some students may have experienced gastrointestinal problems on a trip to to an unfamiliar place or an infection from swimming in polluted water, but most Americans won't have experienced much in the way of waterborne illness.) Explain that it is rarely a problem in America, but that it's a huge issue in many other countries. Around the world, 25,000 people die every day due to water-related disease. Ask why it is so much less of a problem in America than in other countries. (Possible answers: access to clean ground water, infrastructure to clean the water, efficient sewage systems.)
2. Tell students that the lesson they are about to begin will look at two essential questions: "How can natural resources affect health?" and "
Do all cultures look at resources in the same way?" Display these questions in a prominent place for the remainder of the lesson.
3. Explain to the class that they will be looking at the quality of drinking water in the United States and in several countries in Africa. Introduce them to the “Decision Process for Drinking Water" (pdf–50 KB) produced by the Environmental Protection Agency. Have them look at the worksheet and read the questions beneath each graphic. Point out that these same decisions need to be made about safe drinking water no matter where the water is—in Africa or in the United States.
4. Divide the class into small groups that they will return to throughout the lesson. Tell them to use “Decision Process for Drinking Water" in their small groups and discuss where along this path of decision making there might be some health concerns for safe drinking water. After a short discussion in their groups, each group should report to the class. It will be likely that students will see that in each decision area (Source, Transport, Treatment, Testing, Delivery, Home) there may be chances for people's health to be affected.
5. Ask students if they know the source of their drinking water at home, and the location of the water treatment plants in your area. It is likely that most students will not know the exact source, so list all of their guesses and assumptions on a chart or overhead that can be kept for the next class period.
6. Tell students that for homework they should find out the source of the water for their area, and the location of the water treatment plants. The following hints might be given: (1) Ask your parents to see a water bill, then see if the billing agent has a website that gives you the information; (2) Check out the EPA website and follow links till they reach information on drinking water Consumer Confidence Reports.
Day 2
1. Have students report their findings about the source of their water and the location of their water-treatment plants. Look back at the list made on the previous class period and compare their assumptions with the reality. 2. Tell students that in this class period they will be involved in conducting an experiment to demonstrate how ground pollutants can affect the source of water. Follow the procedures as listed on the lesson plan from the EPA: “Water Pollution Prevention and Convservation" (pdf–44 KB). Be sure to use the debriefing after the experiment is complete, with questions such as:
What types of things poured on the ground or left on the ground near a water source would affect that source?
What might be the greatest pollutant to the water in our area?
How can you prevent people from contaminating the water source?
3. For homework, have students research the Safe Water Drinking Act. [http://www.epa.gov/safewater/sdwa/30th/index.html] They should look for the 1996 amendments to the act, and find out what it says about contamination of drinking water sources. Students can call the Safe Drinking Water Hotline at 1-800-426-4791.
Day 3
1. Note: If possible, meet with students in the computer lab or media center where students can have access to the Internet.
2. Discuss the homework from the previous class with the students. They should have found out that, in 1996, an amendment was passed to the Safe Water Drinking Act that included a statement saying that states will be examining all drinking water sources to identify contaminant threats and determine susceptibility to contamination, allowing water suppliers, local governments, and citizens to design source water protection measures.
2. Tell students that today they will investigate how drinking water is treated to remove contaminants. Explain that the Environmental Protection Agency has set up an explanation of this for younger children that they will look at before downloading an experiment from the EPA website. Have them go to http://www.epa.gov/safewater/kids/watertreatmentplant/index.html and investigate the water treatment path. This is an interactive site that explains the basics of a water treatment system.
3. After students have had a chance to “play" with the water treatment path, have them go to http://www.epa.gov/safewater/kids/grades_4-8_water_filtration.html and read about how to complete an experiment to demonstrate a water filtration system that includes aeration, coagulation, sedimentation, filtration, and disinfection. You may choose to have students build this model themselves or follow your demonstration. Alternatively, you might assign this building to groups as a project to be completed outside of class time.
Day 4
1. Review the water treatment processes with students, and then ask them how they think water-related diseases are avoided. (Possible answers: Boil water, filter it, or add chemicals such as chlorine or iodine.)
2. Tell students that they will begin to read about water-related illnesses in various countries in Africa. Before they begin, briefly discuss the different ways in which people obtain water in Africa. The vignettes from Peace Corps Volunteers refer to bore holes and pumps. A bore hole is a hole drilled down to an underground aquifer in which a pipe is inserted, and a pump is added at the top. Bore holes are less likely to be contaminated by animals than ponds or standing areas of water. Show students the diagrams of the wells and pumps on the Water in Africa resource page.
3. Distribute the Health and Nutrition Stories by Peace Corps Volunteers serving in African countries (PDF or RTF). (Alternatively, read the information from the Health and Sanitation stories on the Water in Africa resource page.) If you wish to read more than those on the hand-out, focus on the vignettes relating to health and sanitation. As the class reads the vignettes, keep track of the various diseases mentioned in a list on the board. Those mentioned in the vignettes include schistosomiasis, cholera, malaria, amoebic dysentery, giardia, and typhoid Fever.
4. Discuss the observations and photos of the Volunteers. Underscore economic reasons and the lack of infrastructure in explaining why obtaining clean water is so difficult. Refer to what students have learned about groundwater contamination in the previous days to connect with the stories and photos.
Days 5 and 6
1. Ask the students to join their small groups. Distribute the Poster Evaluation Rubric (PDF or RTF). As a class, go over the rubric and make sure students understand what is expected on their finished poster.
2. Have students work in their groups to research a particular disease from the list on the board. Students can use the Internet and library, and they can ask the school nurse to help them find information about the disease they have chosen. They should consider cause, symptoms, treatment, and prevention.
3. Ask the groups to be ready at the end of two class periods to present a poster with the information they have found about their chosen disease. (See websites under resources below.) Evaluate the finished product based on the evaluation rubric.
Day 7
1. At the beginning of class students should briefly describe what they learned about their disease and the groups should present their posters.
2. Following the discussion of the diseases, students should reread the vignettes. As you read as a class, discuss the diseases that are endemic in the African villages. Now that the students know more about the diseases, what suggestions can they make for improving the water quality and supply in the villages? Why aren't some of these solutions already in place? (Some possible answers: It's hard work to collect wood for fuel to boil water; there's an, insufficient amount of wood; animals share water supplies with people, and contaminate it in the process.)
3. Have students re-assemble into groups to brainstorm solutions for the villages that take into consideration the cultural and physical barriers that interfere with water sanitation.
Day 8
For the first half of the class, continue to brainstorm solutions to water issues with the students. For the second half of class, have students work together as a class to draft a plan to decrease waterborne illnesses in the villages they read about. Students should imagine that they are submitting a plan to the World Health Organization, so all their ideas should be realistic and professionally presented.
Assessment
Informal assessment might include the observations of the groups as they work. For a formal evaluation, use the Poster Evaluation Rubric (PDF or RTF).
Follow-up Activities
For students with stronger reading skills, don't limit the number of vignettes they can read to gather information. Allow them to look at all the health and sanitation vignettes on the Water in Africa website.
Invite a doctor, the school nurse, or a public health official to come in to class to talk about waterborne illness and answer students' questions.
Additional Resources
Websites about water-related illness:
http://www.cdc.gov/ncidod/dpd/parasiticpathways/drinkingwater.htm
http://www.who.int/water_sanitation_health
http://dir.yahoo.com/Health/Diseases_and_Conditions/Tropical_Diseases/
http://www.chez.com/malaria/
About the Author
Carly Sporer Garrett was a Peace Corps Volunteer in Mongolia in 1995–96. She currently teaches English and reading at Palomar High School in Chula Vista, CA. She spoke about her reasons for creating this lesson: "I decided to do a project involving waterborne illness, because I want my students to realize how fortunate they are to live in a country with abundant clean water, to increase their knowledge of disease transmission, and to show that solving problems is complex—that a solution is not as simple as it seems at first."
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