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Lesson Plan


		Lesson Information


		Objectives
		Assessment


		Resources
		Materials
		Vocabulary
		Procedures
		Day Plans
		Enrichment Options


		Teacher Reflection

Stage 1
Identify Desired Results

Catchy Title: Chemical Controversy
Theme/Topic of Lesson: endocrine disruption
Time Commitment: 4 days
Subject Area(s):
    Health - Environmental health
    Language Arts - Debate
    Science - Environmental
    Science - Chemistry
    Science - Process skills
Grade Level(s): 10,11,12
Standards Alignment:
Class Challenge Question:

What is the controversial issue about endocrine disruption, and what questions need to be answered to resolve this ongoing debate in the scientific community?

Overview:

The endocrine system is a collection of glands that secrete chemical messages we call hormones. These hormones send messages to different parts of the body, including the reproductive system. Scientists discovered certain synthetic (human-made) chemicals can mimic the natural chemicals that animals use as internal messenger systems in their bodies. They learned that these chemicals could disrupt the normal hormonal signal process in the endocrine system. These disrupting synthetic chemicals became known as endocrine disruptors. There is scientific evidence of how endocrine disruptors affect some animals, however, the verdict is still out on how endocrine-disrupting chemicals affect humans.

In 1996, Theo Colburn published a book entitled, Our Stolen Future, telling the story of how endocrine disruption was discovered and how it works. This publication caused much controversy in the scientific community over the validity of the evidence cited in the book. The controversy about endocrine disruptors centers around the issue of human health implications and whether endocrine disruptors are a possible cause of serious health issues and trends.

Many experts, especially those in chemical and chemical-related industries, believe that inconclusive or inaccurate research raises questions about the link between chemicals and endocrine disruption in humans. Factors such as dosage level, time of exposure (i.e., in-utero), and duration of exposure dictate how significantly a chemical affects the human endocrine system. Within the scientific community, the theory about the effects some chemicals have on the endocrine system is referred to as the endocrine disruption theory.

In this lesson, students will work in teams to explore the endocrine disruption theory, and research materials that support each side of the debate. Students will then engage in a class debate about the issue, with half the class arguing for the validity of the theory and the other half arguing against it. Both sides will be required to cite evidence supporting their position. Following the debate, the class will identify key questions that still need to be answered to resolve the issue. Individually, students will write a one-page position paper on where they stand relative to the endocrine disruption theory.

Stage 2
Determine Acceptable Evidence

Learning Objectives:

The Students will:

develop an understanding of the endocrine disruption theory
work collaboratively in teams to conduct research and develop a persuasive oral argument in support of one side of the endocrine disruption theory
engage in a class debate, arguing either for or aganist the endocrine disruption theory
write a one-page position paper supporting or disputing the endocrine disruption theory
interpret scientific research and different perspectives in order to formulate an opinion that can be substantiated by facts
identify and/or pose meaningful, answerable scientific questions that demonstrates the logical connections between the scientific concepts and what needs to be further investigated

Assessment

Students will be assessed based on the following. See "Chemical Controversy: endocrine rubrics" for grading criteria

(1) Group Debate

(2) One-page position paper

Stage 3
Plan Learning Experiences

Resources

Print Materials	Endocrine System and Hormones Basic information on the endocrine system and hormones for brief review of endocrine system at the beginning of the lesson.
	http://whyfiles.org/045env_hormone/index.html
	Our Stolen Future Coburn, Theo, Plume Publishers, March, 1997. Availalbe at Amazon.com. The book that started the controversy over potential chemicals disrupting the endocrine system. This is a great classroom resource to have on hand. The book also has an accompanying website that students will use in their research.
	http://ourstolenfuture.org/
Internet Sites	Endocrine System Overview Provides a brief overview of the endocrine system to be used in the introductory part of the lesson.
Internet Sites	http://www.epa.gov/scipoly/oscpendo/edspoverview/whatare.htm

Materials

Per class
Chemical Controversy standards  (View)
as determined by instructor
Chemical Controversy student guide

Contains instructions for team research and suggested websites for students
  (View)
Per Student
Chemical Controversy debate organizer  (View)
Chemical Controversy debate rubric  (View)

Vocabulary

endocrine system - a system of glands that regulates bodily functions via hormones secreted into the bloodstream
endocrine disruptors - Chemicals that mimic the body?s own internal hormone communication system that may alter function(s) of the endocrine system and consequently causes adverse health effects

Procedures

This four-day lesson engages students in learning about the endocrine disruption theory and how some substances may be causing human harm. Initial activities for this lesson focus on collaborative team research. Findings will be presented via oral persuasive arguments in a class debate. Following the debate, the class will collectively identify key questions that still remain unanswered. Finally, individual students will be challenged to succinctly articulate where they stand on the theory by writing a one-page position paper.

For the research, teachers should place students in heterogeneous teams of 3-4 scientists. Depending upon class size, there should be about 6-8 teams. For the debate, it is recommended that teachers randomly assign teams to one side or another, rather than allowing teams to chose a particular side. This strategy encourages critical thinking as students may have to understand and argue for something that they don't necessarily agree with. Less important, it also ensures that you have an equal number of students supporting one side or another.

The first day will be spent reviewing the endocrine system and the endocrine disruption theory. Students will be assigned their research teams and formulate a research strategy. The next two days will be spent conducting research, citing evidence that supports both sides of the theory. About halfway through the third day, place teams in debate groups, and have each team report their findings. Each group should then prepare a 3 minute opening argument supporting or disputing the theory.

On the final day of the lesson, students will have about half the class period to continue to prepare for the debate and finalize their opening argument. The class will then engage in a debate. Following the debate, the teacher will guide the discussion about what key questions still remain unanswered.

Modification: Instead of a debate, an easy modification to the lesson would be to have students take on the role of investigative reporters, researching all aspects of the controversy. Students could submit an unbiased news report in the form of a magazine article, newspaper report or video broadcast.

Student Prerequisite Knowledge

Students should have basic Internet research skills as well as familiarity with how to assess the reliability of a website. A review on how to look for inherent bias in a website may be necessary. Students should also have good reading comprehension skills, as they will need to summarize and understand both sides of the endocrine disruption controversy. Finally, an understanding of basic anatomy is necessary, including how the endocrine system works (this lesson only contains a brief review of the system).

If students do not have the pre-requisite knowledge base, it is suggested you spend some time developing these skills.

Teacher Prerequisite Knowledge

Teachers should be familiar with the endocrine system and how it functions, particularly the role that hormones play relative to the reproductive system. Teachers should also be comfortable facilitating Internet research, and helping students make sense of difficult language and understanding multiple viewpoints. It's important also, for the teacher not to show bias in his or her opinion about the theory until after the class debate is over.

Day 1: Endocrine System and the Disruption Theory
Daily Challenge Question: What is the controversy over the Endocrine Disruption Theory?
60 minutes

Set-up Directions:
Have prepared pre-assigned heterogeneous teams.

Optional: Print out pages from the following website and distribute to students http://whyfiles.org/045env_hormone/main3.html

Print out the student_guide.doc for each student for Activity #3

In the first activity, you will be reviewing prior knowledge of the endocrine system and ensuring that there is a collective class understanding of the basic functions. If you suspect that students have very little knowledge of anatomy, you may want to prepare an overhead transparency or simple PowerPoint slide or two that illustrates succinctly the endocrine system. See http://www.epa.gov/scipoly/oscpendo/edspoverview/whatare.htm

Alternatively, if you have access to United Streaming, do a search on "endocrine system" and show one of the introductory video clips to conduct a quick review.

Teacher Presentation & Motivation:
Begin by asking students broadly if they would knowingly harm their bodies. Would they ingest harmful chemicals if they knew they would have adverse health effects? Note, students may think you're going down the path of smoking, drugs or alcohol, so you may want to mention that people do willingly put harmful substances in their bodies every day.

Tell them, however, that you're referring to other kinds of substances found in household and industrial chemicals...pesticides, chlorine, materials used to make plastics, etc. Do they knowingly ingest them? Of course not. Why not? (They're poisonous).

Ask students: "if it's suspected that some substances you or your parents use regularly that might cause harm just by touching or using (or ingesting w/out knowing it), would you continue to use it?"
You might want to discuss, what constitutes "harm."

Ask, "what if we're not sure about the harmful effects, but there might be possible effects that could prevent you from having children in the future, or if you're pregnant, might harm the unborn baby." Take responses.

Tell students that over the next few days they'll be working in teams to try to uncover evidence in an ongoing scientific controversy over chemicals and their potentially harmful effects on the human body.

Activity 1 - Endocrine System
Only about 15-20 minutes should be spent on a quick review of the endocrine system.

Put students into their heterogeneous pre-assigned groups. Give them about 10 minutes to discuss what they know about the endocrine system and how it functions. Optionally, assign a part of the endocrine system to each team and ask them to report out to the class what hormone(s) are produced and what kinds of signals are delivered inside the body. Use the resources found at http://whyfiles.org/045env_hormone/index.html as a guide. Direct students to focus on the relationship of the endocrine system to the reproductive system.
Come back together as a class, and build a common, collective understanding of the endocrine system. Call on each team to report on what they know.
If necessary, review information from the following site http://www.epa.gov/scipoly/oscpendo/edspoverview/whatare.htm

Hormone Basics,
http://whyfiles.org/045env_hormone/main3.html
be sure to click on "what these things do." http://whyfiles.org/045env_hormone/caption.html

Summarize the activity by noting that particular emphasis will be placed on how the system functions relative reproduction.

Activity 2 - Endocrine Disruption
Now that students have a basic understanding of the endocrine system, ask students what they think "endocrine disruption" refers to. Take student responses.

The following explanation in part, is taken from the EPA’s site on endocrine disruption. See: http://www.epa.gov/scipoly/oscpendo/edspoverview/primer.htm

Explain the following:

Certain artificial chemicals can enter the bloodstream and mimic hormones, sending bad signals or blocking normal signals. Because hormones are part of the endocrine system, these artificial chemicals are known as endocrine disruptors. . Chemicals can disrupt the endocrine system in several ways. They can mimic or block chemicals naturally found in the body, alter hormonal levels, and thus, affect functions that these hormones control. Less direct interferences involve alteration of the body’s ability to produce hormones, interference with the ways hormones travel through the body, and changes in numbers of receptors.

Further explain,

Some chemicals mimic a natural hormone, fooling the body into over-responding to the stimulus (e.g., a growth hormone that results in increased muscle mass), or responding at inappropriate times (e.g., producing insulin when it is not needed). Other endocrine disrupting chemicals block the effects of a hormone from certain receptors (e.g. growth hormones required for normal development). Still others directly stimulate or inhibit the endocrine system and cause overproduction or underproduction of hormones (e.g. an over or underactive thyroid). Certain drugs are used to intentionally cause some of these effects, such as birth control pills. In many situations involving environmental chemicals, however, an endocrine effect is not desirable.

Continue...
In the 1990s, some scientists proposed that chemicals might inadvertently be disrupting the endocrine system of humans and wildlife. Many chemicals were found to disrupt the endocrine systems of animals in laboratory studies, and there is strong evidence that chemical exposure has been associated with adverse developmental and reproductive effects on fish and wildlife in particular locations. The outcome of these findings is known as the endocrine disruption theory.

Optional: If you have the book, Our Stolen Future, now is a good time to reference the book, citing more about how the theory came to be in 1996.

Segue into the next activity:
The relationship of human diseases of the endocrine system and exposure to environmental contaminants is still poorly understood and scientifically controversial. There is an ongoing debate about the validity of the initial evidence cited to support the theory.

Activity 3 - Uncovering the Evidence
Explain to students that they will be working in their scientific teams to uncover the evidence supporting both sides of the scientific debate.

Distribute and review student_guide.doc to make sure students understand their research assignment.

Tell students that it is important that they uncover and understand all perspectives in the controversy, since they don't know which side they will have to argue for in the class debate.

Wrap Up:
Do a brief summary of the endocrine system and the endocrine disruption theory. Explain that the relationship of human diseases of the endocrine system and exposure to environmental contaminants is poorly understood and scientifically controversial; it is the students' job to uncover evidence.

Suggest that students begin their research at home, and come prepared to discuss their findings with their teams.

Day 2: Student Research: Uncovering the Evidence
Daily Challenge Question: What scientific research exists to validate or dispute the endocrine disruption theory?
60 minutes

Set-up Directions:
Be sure to reserve a computer lab for student research.

Teacher Presentation & Motivation:

Begin by asking students to define bias.
Ask students what it means if a website is biased. Take responses.
Provide a simple example such as a travel destination website. On the website a potential traveler might find beautiful pictures and information about luxeries, accommodations, etc. The inherent bias is simply that the site (or rather the company publishing the site) is trying to sell something...namely, their destination. In fact, they may deliberately leave out important information that might deter a traveler from choosing their spot. This is inherent bias.

So what does this have to do with scientific research?

Advise students to be aware of bias in their research, and consider reasons for inherent bias found in some websites.

Ask if there are any general questions before students begin their research.

Activity 1 - Student Research
Students will use the entire class to work in their research teams to uncover evidence that both supports and disputes the endocrine disruption theory.

Focus for Media Interaction
Focus for Media Interaction: The focus for media interaction is a specific task to complete and/or information to identify during or after viewing of video segments, Web sites or other multimedia elements.
Using student_guide.doc as a guide, students will find evidence that both supports and disputes the endocrine disruption theory in order to prepare to argue one side of the debate.

Viewing Activities
What will your students be responsible for while viewing this piece of multi-media or video?
Students are responsible for uncovering evidence to support and dispute the endocrine disruption theory.

Post Viewing Activities
How will students utilize the information they gathered while viewing the multi-media or video?
Students will use the evidence they find to develop a persuasive oral argument either supporting or disputing the endocrine disruption theory.

Wrap Up:
Bring the teams back together as a whole class. Without going into too much detail about their research and findings (this will be done as they debate), discuss the bias of some sources (i.e., chemical manufacturers claim there is not enough evidence to support the theory). Discuss why some companies/organizations are more biased than others and the reasons for this.

Day 3: Continued Research and Debate Prep
Daily Challenge Question: How can I prepare to argue a point of view that I don't necessarily support?
60 minutes

Set-up Directions:
Access to a computer lab for student research is required. Ideally, teams who have completed their research should have an area to work in small groups, away from computers.

Be sure to have enough copies of the Debate Organizer ready to distribute to each student.

Teacher Presentation & Motivation:
Announce today's activities:

students will have about half the class period to finish their research
teams will be put into one of two groups
in their assigned group, each team should select one reporter to report their findings
groups will have time to prepare for the debate, including preparing one 3-minute opening argument for their group

Activity 1 - Continued Research
Students will continue to work in their teams conducting research in order to prepare to argue for or against the endocrine disruption theory.

Activity 2 - Prepare to Debate
About halfway through the class, have students wrap up their research. Let them know they can continue their research at home if they still have some sites that they need to investigate.

Randomly assign teams to Group 1 or Group 2

Group 1 will be the scientists who support the endocrine disruption theory.
Group 2 will be the scientists who dispute the endocrine disruption theory.

Distribute the Debate Organizer to each student. Individually, everyone is responsible for completing the organizer prior to the debate, in order to ensure everyone is prepared to participate in the debate.

Students will work in their groups with each team's reporter, reporting their team's research findings.

After each team has reported their findings to the group, the group will need to prepare ONE 3-minute opening argument for the debate. Each group should choose one person to read their opening argument.

Wrap Up:
Does each group feel like they have enough evidence to argue their side?

Announce to the class that they will have about half the class period to continue to prepare for the class debate.

For homework, individual students should continue to fill in their Debate Organizer.

Day 4: Class Debate
Daily Challenge Question: What questions remain unanswered in the ongoing controversy over chemical effects on the endocrine system?
60 minutes

Set-up Directions:
Be prepared to moderate the class debate.

Be prepared to wrap up the lesson by guiding students to come up key questions that still remain unanswered (these are listed in the wrap up section).

Teacher Presentation & Motivation:
Everyone should have their Debate Organizer prepared with appropriate arguments.

Announce to the class that they will have about 20-30 minutes to organize their notes and prepare to debate. It is up to the groups to develop a debate strategy.

Discuss briefly some debate strategies:

student presenting open argument should read the prepared statement, and get feedback from the group on any additional points to make
students can play "devil's advocate" citing evidence from their opponents in order to help them articulate their responses

Announce that following the debate, as a class they will discuss the questions that still remain unanswered. As the class debates, they should be thinking about these unanswered questions.

Activity 1 - Prepare to Debate!
Using some strategies discussed as a class, as well as their own ideas, students will work in their groups to prepare for the debate.

Activity 2 - Debate: Controversy over Chemicals
The teacher is the debate moderator.

Begin by randomly selecting a group to present their opening argument. The selected student in each group will read the prepared three-minute opening argument.

After both sides have presented their argument, engage the class in a debate.

Wrap Up:
As a class, summarize the debate, and discuss some of the outstanding issues. Guide the following discussion, ensuring that students end the lesson with the understanding that there are still some unanswered questions that need to be answered in order to resolve the controversy.

What are some of the possible endocrine disruptors:

Dioxins – toxic byproducts of paper manufacturing and incineration
Chemicals in pesticides and chemicals that result from the breakdown of banned pesticides such as DDT
PCBs – chemicals used in electrical equipment that are found in river and lake sediments in industrial areas
Chemicals found in the epoxy lining of "tin" cans
Plastics used for storing food (e.g., bisphenol-A in polycarbonate plastic)
Dental sealants sometimes used on the teeth of children
Chemicals in detergents (e.g., nonylphenol)
Fungicides used on fruit, such as Vinclozolin

What do scientists agree on?
some chemicals could interfere with the endocrine system at high doses and that large enough doses of such chemicals could cause harm to people or animals

What are the key questions that need to be answered, supported by scientific research:

• Is human health being adversely affected by small amounts of manmade chemicals in air, water and food that may interfere with their endocrine systems
• Can exposure to small amounts of chemicals interfere with endocrine systems and lead to harmful effects on human health?
• What are the threshold amounts, and during what stages of human development, can chemicals produce harmful effects via changes in endocrine function?
• Are laboratory test tube procedures accurate predicators of actual human impact?

For homework, students will write a one page position paper on where they stand on the endocrine disruption theory.

Enrichment Options

Community Connection
Invite a local endocrinologist to come in and talk about the endocrine system

Parent-Home Connection
Have students communicate with family members about what they can do to limit their risk of exposure to suspected endocrine disruptors.

Cross-Curricular Extensions
Chemistry - have students delve into the chemical breakdowns of various chemicals

Biology and Wildlife - focus on the long term exposure of endocrine disruptors on certain wildlife and discuss how this has affected the environment and the organisms' ecosystems

Stage 4
Teacher Reflection

As a reflective practitioner, note how this lesson could be adjusted after its initial implementation. How successful were the students in demonstrating their knowledge about the subject matter? What did the assessment demonstrate about the students' learning? What skills do the students need to revisit? What instructional strategies worked and what made them successful? What will you change the next time you use this lesson? Why?

Author: Donna Schnupp