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High School Food Safety Lessons
Lesson
4 Irradiation Web Quest
National
Health Education Standards
(grades 9-11) 1:1, 2:1, 4:3, 7:2
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| introduction |
- Introduce this lesson: (modify if necessary)
“Today we are going to discuss food irradiation. Irradiation is used
to kill some of the food pathogens in the food you studied in
the last lesson. High-energy electrons or gamma rays are passed through
the food. This breaks the DNA in the bacteria and prevent the
bacteria from replicating—this inactivates or kills the bacteria.”
- Question:
“Does anyone know what irradiation has to do with NASA?” (In
space, astronauts eat foods that have been treated with irradiation
on earth.)
- Question:
“Can anyone tell me how we know that the food we purchase in the
grocery store has been irradiated?” (It must carry a sticker
and the statement "treated with radiation.) Replicate
sticker on the board (see Teacher Resource).
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| activity 1 |
- Distribute student handout Irradiation:
Points of Controversy (found in Teacher Resource) to students. Give students
five minutes to read.
- Discuss:
“What is irradiation?” (Treating food with a measured dose
of radiation to kill harmful substances.)
- Ask:
“What are the advantages of irradiation?” (Irradiation
reduces or eliminates pathogenic bacteria, insects, and parasites.
It reduces
spoilage and in certain fruits and vegetables, it inhibits
sprouting, and delays the ripening process. It does not make
food radioactive,
compromise the nutritional quality, or noticeably change food
taste, texture, or appearance as long as it is applied properly
to a suitable
product.)
- Discuss with students:
“How do you know irradiation is safe?” (The Food and Drug
Administration has evaluated irradiation safety for 40 years
and found the process
safe and effective for many foods.)
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| activity 2 |
- Share with students:
“We are now going to view Module 3
of Dr. X and the Quest for Food Safety. Please watch carefully
for Irradiation as a way of processing
food. This is the subject of our lesson today. You will also
hear a discussion of pasteurization, and ultra-high pressure treatment
in this module.”
- Discuss with students:
Follow the video presentation with a brief discussion
about the issues presented and
clarify any misconceptions students may have gained.
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| activity 3 |
- State:
“Now I would like the class to divide
into four or five expert groups. Each group will draw three cards
from this bowl. On each card
is a number. You are to become experts on the questions found on the
Irradiation Web Quest that I am handing out. The numbers your
group has chosen are the questions which each group will become experts.
You will have ten minutes. You will share your expertise with
the rest of the class. Be careful to complete the answers to your questions
carefully. Write legibly please. These will be copied or posted
so you will each have a compete set of answers.”
On
the board you will find a web site for reference.” (optional)
(www.cfsan.fda.gov/~dms/fdirrad.html.)
- Add:
“ If you have time later, you can also refer to the other
web sites I have placed on the board.” (optional)
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| activity 4 |
- Discuss with students:
Hold a discussion with your students calling on each of the four
or five groups to answer the three questions they have been researching.
Make appropriate summary remarks at the end of each presentation,
drawing on other students in addition to the team leader.
- Reinforce with students:
- If you have taught lesson 3, be sure to draw parallels between
this lesson and lesson 3. Especially reinforce for students
that three harmful bacteria, E. coli O157:H7, Salmonella, and Campylobacter can be reduced or controlled by irradiation.
- Ask the teams
to give you their papers, copy the four or five papers, and
distribute a set to members of the class.
As an alternative, post the papers.
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| Closure |
Review the lesson by saying:
“This was a powerful lesson in food safety
and how irradiation plays a role in reducing the incidence of foodborne
illness that
we covered
in lesson three. Irradiation, as we have learned, destroys microorganisms
by damaging the DNA in microbes. The Food and Drug Administration
(FDA) has evaluated irradiation safety for 40 years and found the
process to be safe and effective for many foods.” |
| Integration ideas |
- Check Integration Ideas, Lesson
3, for
many ideas on how students can share their knowledge.
- Students can conduct a survey among family members, friends,
and classmates to ask if they would eat irradiated food. A
well-researched fact sheet on irradiation can then be given to
the same population.
This fact sheet needs to be reviewed by the health teacher.
This activity can be followed by a repeat of the survey to determine
if the fact sheet resulted in changes in attitude about consuming
irradiated foods. This activity could be carried out in cooperation
with the math department. Survey writing and analysis is a
learned
skill. (Final questions on the survey need to be checked by
the health teacher.)
- A helpful brochure can be developed on the topic of irradiation
in cooperation with the health, English, and art departments.
This brochure can be distributed to faculty, students, and parents.
Seek the principal's cooperation early in the process.
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