Read
Assess students’ background knowledge by asking them to share facts about pollutants and toxic substances. “What are pollutants?” “What are toxic substances?” “What do you know about pollutants and toxic substances?” “How do you think pollutants and toxic substances connect with caribou studies?” “What materials might bring pollutants and toxic substances into caribou habitats?” “How might pollutants/toxic substances affect caribou and the people living in the same Arctic region?”
During the discussion, introduce a question about nuclear power plants and their potential threats. Ask students to share what they remember about the nuclear power plant explosion in Chernobyl. Invite students to search the Internet to research Chernobyl and collect background facts that will help them understand information in the upcoming article.
Introduce the selection by making anticipatory predictions. “As you think about the title and the subtitle of this article, what facts do you think the author will include in the article?” “What questions do you think a reader will find answers to in this article?”

Read the nonfiction article, “Cesium, Cadium, and Caribou: Some Facts about Heavy Metals and the Food Chain” as students follow along with their own copy of the text.

Revisit
Revisit the article to circle the words: some, only, always, many, and most. Reread the sentences that contain the circled words. Ask students:

• “What does a reader need to think about when an author uses words and phrases to generalize ideas?”
• “How would the meanings change if the author used more specific language in place of the circled words?”

Have students work in small groups to generate challenge questions based on the information in the selection. Invite the groups to exchange and answer each other’s set of questions. Decide whether students can refer to the selection or not to answer the exchanged set of challenge questions.
Examine the article for how the author included context clues and descriptive details to help readers understand complex words and ideas. Have students give specific examples from the text to support their responses.
Ask students the following questions:

• What ideas from this article were difficult to understand?
• What would you change or add to the article to help other students read and understand the information?
  
  

Reflect
Journaling Questions:
This article described cause and effect relationships.

1. What were the potentially dangerous events described in the article?
2. What were the causes or reasons the potential threats existed?
3. What thoughts do you have about the information you learned from reading this article?
4. What actions do you think need to be taken to prevent potential threats from impacting caribou in the future?

Making Connections: The Age of Technology

• How is technology used to help people and animals?
• What are the benefits of living in a high-tech world?
• What are possible disadvantages?

Invite students to conduct a survey using these Connection Questions. Encourage them to interview people of different ages to get a broad sample of information to analyze. Have them inventory the technological tools that they use in their everyday life. Have them share predictions about how their life would be different without the technology.

Making Connections:
How do we prevent toxic substances finding their way into the foods we eat? What precautions help prevent potentially toxic substances from invading our bodies? Encourage students to discuss food storage, preparation, and consumption. Depending on the age of students, discuss how food is grown, chemicals used in farming and food production, chemicals used to clean household surfaces, insecticides, and other ideas that help them examine this important issue.

Evaluation (Examine Author’s Strategies)
Why do you think the author started the article with a question?
Reread and evaluate the title, subtitle, headings, and other text features. How did these elements help readers understand the information in this article?
The author refers to research studies and testing within the article. What details did the author provide to readers about the testing and research studies? What questions do you still have after reading the article?

• Descriptive
  Create dictionary pages that feature key words from your caribou studies. Include words and concepts from this selection.
• Expository
  Create an informational flyer about proper storage and preparation of food for young cooks starting out in the kitchen.
  Research facts about the nuclear power plant in Chernobyl. Write an informational piece for young readers about this historic event. Why do you think young readers should remember Chernobyl? How do you think this knowledge will help them make healthy decisions about our world?
• Pursuasive
  Write a letter to a person in a “position of power.” Who makes decisions that dramatically affect the environment? Who decides about the use of insecticides? Who decides how food is grown, packaged, delivered, prepared, etc. In your letter to this key player, urge them to make decisions that will help take care of our fragile planet.