Embedded Files
Title: Help Stop the Spread of Foodborne Illness
Principle(s) Investigated:How microorganisms survive and how they are eradicated.
Standards: 5.3.N Demonstrate how to use safe food handling procedures when preparing meals and snacks.
Materials:
Glo Germ powder/lotion (1 per group)
a UV light (1 per group)
paper towels
soap and water
8.5” x 11” piece of paper and a pencil for each student
colored pencils or crayons
Procedure:
1. Explain how it is important that we wash our hands before preparing or eating food. If we do not wash our hands properly we can become sick by bacteria or virus that reside on our hands when we touch the food we eat or prepare for others.
2. Give each student with a blank piece of paper and a pencil.
3. Tell them to trace around one of their hands in two different spots on their paper with the pencil. Then have them set both aside.
4. The teacher will walk around and place a nickel-sized blob of Glo Germ powder/lotion onto the palm of one hand of each student.
5. Next, the students should rub the powder/lotion onto both hands, being sure to cover the areas between their fingers and around their fingernails.
6. Any excess powder/lotion should be wiped off with a paper towel.
7. The teacher explain that the powder contains tiny particles that fluoresce, or glow, under ultraviolet light. Then the teacher tells the students we are going to pretend that these tiny particles in the powder are bacteria or “germs.”
8. The students then look at their “germ”-covered hands under the ultraviolet lamp. They will see glowing areas on their skin, nails and around their cuticles.
9. Tell the students to wash their hands using soap and water the way they usually do.The effort it takes to completely wash the powder off one’s hands is similar to the effort it takes to remove most bacteria.
10. Then they recheck their hands under the UV light. Then the students will draw the remaining what "germs" they see on the first diagram of their hands.
11. The teacher mentions that germs can be trapped in certain areas (i.e. chapped/cracked skin,). Our skin protects us from microorganisms from getting inside our body. So, we should keep our skin healthy and intact to help prevent germs from getting into about bodies.
12. They will wash their hands one more time while singing or humming the "Happy Birthday" song two times. The song when sung twice takes about 20 seconds. We need to take about 20 seconds to get off all the microorganisms.
13. Now the students will put their hands under the light again and then draw any "germ" that are left in the second hand diagram on their papers.
14. The students will compare their diagrams with each other in their groups. They will write a paragraph of similarities and differences they see in their own hand diagrams with at least one other student.
Student prior knowledge:
Students need to understand that one cell organisms called bacteria are so small they can not be seen by the naked eye. Although bacteria cannot be seen, some types of the organisms can cause foodborne illness . Such as salmonella entercolitis, if in contact with food and ingested by humans.
Explanation:
Foodborne illnesses, typically called food poisoning, happens when someone “ingests disease-causing bacteria, viruses, or fungi, or toxins (poisonous substances) made by them." (Clarke, 2015). This could happen when someone preparing food does not properly wash his/her hands or the work surface properly. One of the most common foodborne illnesses is salmonella entercolitis, an infection of the lining of the small intestine, caused by Salmonella bacteria. “More than 30 % of all such illnesses result from unsafe handling of food at home.” (Donatelle, 2013).
People must make sure they get every nook and cranny (chapped or cracked skin) in their hands cleaned with soap and water. These crevices can trap bacteria. So, it is important enough time is taken (about 20 seconds) to totally wash all parts of our hands. A good gauge for 20 seconds is to hum the Happy Birthday song from beginning to end twice.
Resources-
(2015 Educational Innovations, Inc. Phone (203) 74-TEACH (83224) 5 Francis J. Clarke Circle Fax (203) 229-0740 Bethel, CT 06801)
Donatelle,Rebecca, Health,the Basics 10 edition, 2013.
Questions & Answers:
1. Does it matter what type of soap we use to have clean hands?
Most any type of soap works. However, some soaps (i.e. dish washing liquid) remove a lot of oils in our skins causing our skin to dry out, making it chapped, and peeling. So, oil removing type soaps are best to be used for their purpose of cleaning dishes, not hands. Antibacterial soaps are not recommended (refer to Question 1 a.)
1 a. Are antibacterial soaps more effective with cleaning our hands?
No, antibacterial soaps are no more effective to cleaning our hands that regular soap and water. Besides, antibacterial soaps are not recommended since they can create organisms in the future that are resist to the soap. *Read question 2 for further information on resistant bacteria. Lastly, antibacterial soaps are bad for the environment, since the residue (which can have the chemical triclosan in it) is flushed into our drains . After the water is treated there are still levels of triclosan present. Troclosan can disrupt the environment in out streams and other bodies of water by interrupting the ability of algae to perform photosynthesis.
2. Would hand sanitizers work just as well or even better then soap and water to get rid of bacteria?
*No, they do not work as well as simply washing with soap and water. Our hands are an ecosystem in itself. When we wash our hand with soap and water we actually remove the microorganisms from our skin. However, when using only hand sanitizer the organisms, are not removed. Instead, the environment is changed on our hands where some organisms are killed and others having difficulty surviving. Some microorganisms are resistant to sanitizers and remain on our hands, allowing them to reproduce. In turn, allowing more microorganisms to be resistant to the hand sanitizer. Therefore, proper hand washing is more effective and safer for the environment, than using hand sanitizer.
Applications to Everyday Life:
If we did not wash our hands, bacteria would continue to multiply or reproduce. This same concept can be seen in many areas of living science:
- Reproduction of algae- if no man- made or natural predator kills off algae it will continue to multiply.
- Reproduction of the cell- If a (cancer)cell is not terminated it will continues to reproduce
- Cockroach continue to multiply (quickly) if they are not exterminate or “washed away”
Photographs:
Two types of Foodborne Illness.
Videos: Hand washing video.
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