BioEd Online

Teacher Background

The Science

Microbes, or “germs” that make people sick, come from many sources. They can end up on your hands in many ways, including

•    feces (poop) from animals or people (after they have used the toilet or changed diapers);

•    coughing or sneezing into your hands;

•    touching surfaces (door handles, etc.) that others also touch without clean hands; and

•    handling raw meat or pet food and pet treats.

Washing your hands often, especially after any of the these activities, is always important to limit the spread of illness and infections to others. During the COVID-19 pandemic, correct and frequent handwashing is especially critical to reduce the spread of the coronavirus!

Respiratory droplets from a person infected with SARS-CoV-2 (coronavirus) can land on surfaces and objects. So, it is possible that a person could get COVID-19 by touching something that has the virus on it and then touching their own mouth, nose, or eyes. Available data indicate that this mode of transmission is less common than transmission of the virus through the air.

 

Objectives and Standards

Students will describe why washing hands is important, explain the proper way to wash their hands, and compare washing hands with soap with the use of hand sanitizer.

Science, Health, or Math Skills
Observing

Communicating

Identifying and practicing personal health habits
 

NGSS Science & Engineering Practices

Engaging in Argument from Evidence

 

Materials and Setup

Materials

Slide Deck: "Clean Hands Knock Out Germs!"

Extensions for Knock Out Germs (included at the end of the activity procedure)

 

Set Up

This lesson, including the "Clean Hands Knock Out Germs!" slides, can be used as an interactive activity, with the teacher leading discussion through open-ended questions. The teacher may ask for oral responses, have students answer in journals, or have students provide written responses as homework.

Alternatively, the lesson can be assigned for asynchronous student viewing, along with suggestions to extend or assess understanding (see Extensions for "Clean Hands Knock Out Germs!" below).

Note: Extension activities are included for various grades to provide opportunities for students to apply what they have learned and, if needed, create a product for assessment.

 

Procedure and Extensions

Engage

1. Begin by asking, What can you do to protect yourself from infections? Accept all answers. Mention that handwashing is one strategy to reduce the spread of diseases. Ask, How many of you washed your hands today? When? [Responses may include before eating, after using the bathroom, etc.] Follow up with additional questions as appropriate to guide the discussion. For example, if someone mentions before eating, ask, Why is washing your hands before eating important? [When you eat without washing your hands, microbes on your fingers can be transferred to your mouth. This can lead to illnesses.]

2. Explain that in this lesson, we will explore why washing hands is important, especially during the COVID-19 pandemic when so many people are becoming ill.

Explore and Explain

3. Use the accompanying slides to gude a discussion about the importance of handwashing for disease prevention. If students raise questions for which you do not have an anwer, use them as opportunities for students to do their own research using the Centers for Disease Control and Prevention (CDC) resources listed at the end of this activity. 

Slide 1: Read the first caption, starting with the question, “What’s a germ?” Check for understanding about microbes. Microbes are tiny organisms that can live in the air, water, soil, and the human body. Microbes, which also are called microorganisms, are too small to be seen by the naked eye. 

Continue by discussing the rest of the slide. Depending on the ages of your students, you may want to point out that COVID-19 is a simple acronym in which CO stands for “corona,” VI for “virus,” and D for “disease.” The 19 indicates that the first outbreak of this previously unknown viral infection occurred in 2019.

Slide 2: Ask students for ideas about why handwashing is important. Allow time for a discussion of ideas, and accept all responses without correcting. Students will have a chance to refine their ideas later.

Slide 3: Ask, When you cough or sneeze, what do you do to prevent the spread of germs? Make certain that students mention the importance of covering a cough or sneeze with a tissue (which should be thrown away after use) or the inside of the elbow. These actions should be followed by hand washing.

Slide 4: Read the text and bring attention to the hand. Ask, What are some of the ways that we spread germs? Allow time for discussion. Use the next few slides to discuss students’ ideas further.

Slides 5–7: As you move through the slides, which illustrate different ways in which we can spread microbes on our hands, pause often to check understanding or to encourage discussion with guiding questions.

• Germs from unwashed hands can get into or onto foods and drinks when they are being prepared or served.
• Germs from unwashed hands can be transferred to surfaces or objects that are touched, like handrails, computer keyboards, or doorknobs.
• A single gram of human feces (“poop”) contains up to one trillion germs, so washing hands with soap after using the bathroom or changing a diaper is important.

Slide 8:  Take time to explain that touching your face (eyes, mouth, nose) allows germs to enter your body. Touching others (shaking hands, holding hands, etc.) or surfaces spreads germs from one person to another. Ask, How do you know if other persons are keeping their hands clean? Emphasize that we usually don’t know if others have washed their own hands, so it’s important to wash our own hands frequently.

Slide 9: Read or have students read out loud the steps for good handwashing.

Slide 10: Watch the video linked in the slide, pausing as needed to emphasize key points or answer questions.

Slide 11: Students may have questions about why or when to use hand sanitizers. Read or have students read out loud the guidelines on the slide. Ask students, When might it be better to use hand sanitizer instead of soap and water?

Remind students that soap and water is preferable to hand sanitizer, whenever possible. If needed, provide the following additional information:

• Instant hand sanitizer with >60% alcohol does kill coronavirus and most germs effectively. However, it’s not as effective as washing with soap and water for some disease-causing microbes like norovirus.
• Instant hand sanitizer is not as effective as soap and water at removing germs or chemicals from hands that are heavily soiled with a lot of dirt or materials that are greasy or sticky.

Slide 12: Tell students that washing hands is just one of three things we can ALL do to stop the spread of the COVID virus. Remind then that we all have to do three things together! Wear a face covering. Wash your hands. Watch your distance from others.

Extension or Evaluation 

4. Depending on the grade level(s) you teach, use one or more of the activities below for students to complete on their own or extend the lesson, or use them as an assessment tool to check for understanding.

Grades K–2: Write Your Own Handwashing Song
Even though you cannot see them, germs come in many different shapes, sizes, and colors. Trace your hand on a piece of paper. Now imagine you have a microscope. Can you draw what you think the germs on your hand might look like?

Grades 3–5: Write Your Own Handwashing Song
The Centers for Disease Control and Prevention (CDC) recommends that people wash their hands for 20 seconds (the amount of time it takes to sing the “Happy Birthday” song twice). Can you write your own song or poem that takes 20 seconds to complete (or that can be repeated to last 20 seconds)?

Grades 3–5, 6–8: Create a Public Service Announcement
Public Service Announcements (PSAs) are used to inform people about important programs, services, or issues. Many PSAs have been created to raise awareness of best practices during the COVID-19 pandemic. For example, think about PSAs with athletes promoting mask wearing. 

Can you create a PSA poster to promote handwashing, either at home or at school?

• Use factual information from the slideshow you have seen.
• Make the PSA original (your own work). It should be creative and appealing to catch the attention of others!
• Follow any other instructions your teacher gives.

Grades K–2, 3–5, 6–8: How Many Times Does Someone Touch Her or His Face?
The Centers for Disease Control and Prevention (CDC) stresses the importance of NOT touching your face (eyes, nose, mouth) because this is how germs, including coronavirus, enter your body.

• Next time you are on a video call or at home with someone in your family, keep track of how many times people touch their faces with their hands.
• Don’t tell them you are watching for this, but keep a tally of how many times it happens.
• Do some people touch their faces more frequently than others? How many times do YOU touch your face?

Handouts and Downloads