Lesson 2: Unhealthy Water - What Is It?

Grade 5-8 (Integrated social, science, health and math)
Grade 9-12 (Integrated social, science, and health)

Topic: Defining unhealthy water, and the discovery that water can carry diseases.

Time: 60 minutes

Space Requirement: Regular classroom

Methodology: Presentation, question and answer, journaling

Materials: Question and answer sheet, overhead projector, PowerPoint projector and computer

Objectives: The students will begin to examine unhealthy water by learning about John Snow and his work with waterborne diseases.

For the Teacher: The goal for this lesson is for students to realize that water that is meant for drinking can be contaminated. They should also conclude that water can be made safe through proper treatment.

Directions/Procedure:

  1. Before class, put the picture from below onto an overhead. Show the class what unhealthy water looks like. (5 min)
    a. The students are to discuss the picture. They should consider what the picture is of, what the water looks like, what the water might be used for, who might use the water, and where in the world the water might be from (it is actually from a First Nations community in Canada; Saddle Lake Cree Nation in Northern Alberta!).
     
  2. Have the students make a list of reasons what can make water unhealthy and briefly discuss their lists:
    a. Reasons may include: pollution, bacteria, sewage, algae, pesticides, fertilizers, herbicides, viruses, parasites.
  3. Hand out the question sheet (see below; there are separate question sheets for elementary and high school) and read through the questions. (2 min)
     
  4. Play the PowerPoint presentation about John Snow and the cholera epidemics. (30 min)
    a. Students should answer the questions as the power point plays; they will hand in their answers at the end of the class.
     
  5. Have the students debrief the PowerPoint by discussing the handout questions and any others that may have arisen during the lesson. (8 min)
     
  6. Have the students make a new entry in their water journals regarding the following question: “Why should we care about healthy water?” (5 min)

Evaluation: The teacher will collect the question sheets from the John Snow presentation and will examine the answers for completion and understanding.

Resources: The John Snow PowerPoint presentation is available here.
The following resources and handouts are found below:

  • Picture for overhead (print in colour for best results)
  • John Snow Questions and Answer Key (Elementary)
  • John Snow Questions and Answer Key (High School)

Extension Activity: The Safe Drinking Water Foundation has other educational programs that can be taught with this set of lessons. Operation Water Drop examines the chemical contaminants that can be found in water; this program is designed for a science class. Operation Water Flow explores the use of water and where it comes from; this program is designed for a Social studies and Math collaboration. Operation Water Spirit presents a First Nations perspective of water and water issues and is designed for a Native Studies or Social Studies class. Operation Water Health explores common health issues surrounding drinking water in Canada and around the world and is designed for a Health, Science and Social Studies collaboration. To access more information on these and other educational activities visit the Safe Drinking Water Foundation website at www.safewater.org.

Sources and Related Links:

Unhealthy Water Lesson 2

John Snow Questions (Elementary):

  1. How old was John Snow when he began to work as an apprentice for Dr. Hardcastle?


     
  2. How many people died in the 1831-1832 cholera epidemic in England?


     
  3. Doctors believed that ____________________ were the cause of cholera but Dr. Snow

    believed that ________________________ were the cause of cholera.
     
  4. What did people complain of first when they became sick with cholera?


     
  5. Where was the third outbreak of cholera located?


     
  6. Who finally agreed to remove the pump handle of the Broad Street pump? Did they agree with Dr. Snow’s germ theory?


     
  7. In what year was cholera finally proven to be caused by bacteria? Who made the discovery?


     
  8. What are the main symptoms of cholera? What is the main cause of death for people infected with cholera?


     
  9. Is cholera preventable? How can you keep from getting cholera?

 

John Snow Questions - Answer Key (Elementary):

  1. How old was John Snow when he began to work as an apprentice for Dr. Hardcastle?

    He was 14 years old (in grade 8 by our standards).
     
  2. How many people died in the 1831-1832 cholera epidemic in England?

    50,000 deaths
     
  3. Doctors believed that ___MIASMAS___ were the cause of cholera but Dr. Snow

    believed that ____GERMS___ were the cause of cholera.
     
  4. What did people complain of first when they became sick with cholera?

    Digestive system issues such as diarrhea, nausea, vomiting, stomach cramps
     
  5. Where was the third outbreak of cholera located?

    In a neighbourhood 5 minutes from Dr. Snow's home
     
  6. Who finally agreed to remove the pump handle of the Broad Street pump? Did they agree with Dr. Snow’s germ theory?

    The Board of Guardians removed the pump handle. They did not agree with Dr. Snow about the cause of cholera and thought it was miasmas.
     
  7. In what year was cholera finally proven to be caused by bacteria? Who made the discovery?

    In 1854 by an Italian man named Filipo Pacini
     
  8. What are the main symptoms of cholera? What is the main cause of death for people infected with cholera?

    Queasiness followed by stomach ache, vomiting, and diarrhea. The main cause of death is dehydration.
     
  9. Is cholera preventable? How can you keep from getting cholera?

    Yes it is preventable. Have a clean source of drinking water (sewage and drinking water should never mix), wash hands frequently, especially after using the washroom, before eating, and after playing outside.

John Snow Questions (High School):

  1. How old was John Snow when he began to work as an apprentice for Dr. Hardcastle?


     
  2. How many people died in the 1831-1832 cholera epidemic in all of Europe?


     
  3. Define miasma theory and germ theory.






     
  4. What did people complain of first when they became sick with cholera? Based on the system affected, what are the likely symptoms a person who is sick with cholera would have?


     
  5. During the third outbreak of cholera, what is the logical conclusion that led Dr. Snow to believe the water in Broad Street well was contaminated? How did his research support this conclusion?


     
  6. Who finally agreed to remove the pump handle of the Broad Street pump? Did they agree with Dr. Snow’s germ theory?


     
  7. Describe a scenario where cholera might infect your water source. How would you prove it was cholera? Who would you inform? What steps would you recommend for treating both the people and the water?






     
  8. Who made contributions to finally prove that cholera is caused by bacteria? What did they do?






     
  9. Modern water treatment techniques have improved greatly since Dr. Snow’s time. Is it possible for water to become contaminated now? How might this happen?


     

ohn Snow Questions - Answer Key (High School):

  1. How old was John Snow when he began to work as an apprentice for Dr. Hardcastle?

    14 years old (or in grade 8 by our standards)
     
  2. How many people died in the 1831-1832 cholera epidemic in all of Europe?

    Hundreds of thousands of people
     
  3. Define miasma theory and germ theory.

    Miasma theory states that diseases and illnesses were spread by "poisonous gases that were thought to arise from sewers, swamps, garbage pits, open graves, and other foul-smelling sites of organic decay"
    Germ theory states that diseases and illnesses are spread by microscopic living organisms that can get into food and water and can be spread from person to person.

     
  4. What did people complain of first when they became sick with cholera? Based on the system affected, what are the likely symptoms a person who is sick with cholera would have?

    They complained of digestive problems. The likely symptoms are nausea, vomiting, diarrhea, stomach cramps.
     
  5. During the third outbreak of cholera, what is the logical conclusion that led Dr. Snow to believe the water in Broad Street well was contaminated? How did his research support this conclusion?

    Once he tallied the numbers, he realized that there were 197 deaths, all having occurred among people who had lived within a three-minute walk from the pump. Therefore, the water had to be contaminated.
     
  6. Who finally agreed to remove the pump handle of the Broad Street pump? Did they agree with Dr. Snow’s germ theory?

    The Board of Guardians removed the pump handle even though they didn't agree with Dr. Snow's theory.
     
  7. Describe a scenario where cholera might infect your water source. How would you prove it was cholera? Who would you inform? What steps would you recommend for treating both the people and the water?

    In 1854 Filipo Pacini identified the cholera bacteria while examining sections of intestines from people killed by cholera.
    In the late 1860s, Louis Pasteur demonstrated that microscopic organisms could cause illnesses.
    1884 Robert Koch rediscovered, isolated, and cultured the cholera bacteria, Vibrio cholerae.

     
  8. Who made contributions to finally prove that cholera is caused by bacteria? What did they do?

    A person becomes sick and the sewage enters the drinking water source. A water sample must be analyzed and cultured to determine the exact cause of the illness. If it is cholera, the local Environment authorities and Health district must be informed. A Boil Water Advisory must be broadcast and the water system should be superchlorinated and purged to get rid of any contamination.
     
  9. Modern water treatment techniques have improved greatly since Dr. Snow’s time. Is it possible for water to become contaminated now? How might this happen?

    Yes, it is still possible. If drinking water is taken from a source that is contaminated with sewage the water will become contaminated. If the treated water becomes contaminated with run off from a farm or feedlot. If the treatment plant breaks down and continues to distribute water. **There are many more possibilities.