
Chemicals, the Environment, and You
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Implementing the Module

The six lessons in this module are designed to be taught either in sequence for two or more weeks (as a replacement for a part of the standard curriculum) or as individual lessons that support or enhance your treatment of specific concepts in middle school science. The following pages offer general suggestions about using these materials in the classroom; you will find specific suggestions in the procedures provided for each lesson.

What Are the Goals of the Module?

Chemicals, the Environment, and You is designed to help students develop the following major goals associated with scientific literacy:

What Are the Science Concepts and How Are They Connected?

We have organized the lessons to form a conceptual whole that moves students from an introduction to chemicals and toxicology (Chemicals, Chemicals, Everywhere), to an investigation of the effect of various doses of chemicals on seed germination (The Dose Makes the Poison), to a discussion of the relationship between dose and response that can be represented by a dose-response curve (Dose-Response Relationships). Once students have experienced the process of toxicology testing, they discuss how individual responses to chemicals can vary (Individual Responses Can Be Different), and how knowledge about chemicals can be used to assess and manage risk from chemical exposure (What Is the Risk?). Finally, students consider how their understanding of how chemicals can affect human health can help them make decisions related to personal and public health (Environmental Hazards). The chart below, Conceptual Flow of the Lessons, illustrates the sequence of major concepts addressed by the six lessons.

Conceptual Flow of the Lessons
Lesson Learning Focus Major Concept

Lesson 1
Chemicals, Chemicals, Everywhere

Engage*: Students express prior knowledge and become engaged in the study of toxicology.

Everything in the environment is made of chemicals. Both naturally occurring and synthetic substances are chemical in nature. People are exposed to chemicals by eating or swallowing them, breathing them, or absorbing them through the skin or mucosa, and they can protect themselves from harmful chemicals by blocking these routes of exposure.

Lesson 2
The Dose Makes the Poison

Explore: Students explore the response seeds have to different doses of chemicals. The Explore phase gives students a common set of experiences upon which to begin building conceptual understanding.

The total amount of chemical that is administered to, or taken by, an organism is called a dose, and the effect a chemical has on a living organism is called the response. The effect a chemical has on a living organism is related to dose and the resultant concentration of the chemical in the organism. Toxicity tests enable toxicologists to learn about responses of living organisms to doses of chemicals.

Lesson 3
Dose-Response Relationships

Explain: Students express their conceptual understanding of the laboratory investigation in their own words and using graphs.

Dose and response are related and can be represented by a dose-response curve. Data from toxicology testing can be represented by a dose-response curve, from which scientists can describe the threshold and potency of chemicals.

Lesson 4
Individual Responses Can Be Different

Explain/Elaborate: Students broaden their conceptual understanding and apply what they have learned in a new context.

The variety of responses among organisms that get the same dose of chemical is due to individual susceptibility. Dose and individual susceptibility play roles in all situations involving chemicals, including those involving medicines and caffeine.

Lesson 5
What Is the Risk?

Elaborate: Students extend the module's concepts in a different activity to help them apply scientific terms and concepts in appropriate ways.

People can make some choices about chemical exposure; however, some exposure is controlled at a level other than an individual one. Collective groups of people, such as communities and governments, seek to control chemical exposure on a community or global level.

Lesson 6
Environmental Hazards


People can use their understanding of the science of toxicology to identify potential sources of harm to human health from chemicals in the environment. They can use their knowledge to propose possible means to eliminate or reduce exposure to environmental toxic agents.


How Does the Module Correlate with the National Science Education Standards?

Chemicals, the Environment, and You supports teachers in their efforts to reform science education in the spirit of the National Research Council's 1996 National Science Education Standards (NSES). The content of the module is explicitly standards based: Each time a standard is addressed in a lesson, an icon appears in the margin and the applicable standard is identified. The chart below, Content Standards: Grades 5–8, lists the specific content standards that this module addresses.

Content Standards: Grades 5– 8
Standard A: As a result of activities in grades 5–8, all students should develop abilities necessary to do scientific inquiry and understandings about scientific inquiry. Correlation to Chemicals, the Environment, and You
  • Design and conduct a scientific investigation.

Lessons 2, 4


Lessons 2, 3, 4


Lessons 2, 3, 4, 6


Lessons 3, 4, 6

  • Communicate scientific procedures and explanations.

Lesson 3

  • Use mathematics in all aspects of scientific inquiry.

Lessons 2, 3, 4

  • Develop understandings about scientific inquiry.

Lessons 2, 4, 6

Standard B: As a result of their activities in grades 5–8, all students should develop an understanding of properties of matter.
  • There are more than 100 known elements that combine in a multitude of ways to produce compounds, which account for the living and nonliving substances we encounter.

Lesson 1

Standard E: As a result of their activities in grades 5–8, all students should develop understandings about science and technology.

Lessons 1, 5


Lessons 1, 4, 5

Standard F: As a result of their activities in grades 5–8, all students should develop an understanding of
  • personal health

Lessons 4, 5, 6

  • natural hazards

Lessons 1, 5, 6

  • risks and benefits

Lessons 1, 5, 6

Standard G: As a result of their activities in grades 5–8, all students should develop an understanding of the history and nature of science.
  • Understand science as a human endeavor.

All lessons

  • Understand the nature of science.

All lessons

  • Understand the history of science.

Lesson 5

Teaching Standards



Assessment Standards








The Engage lesson in this module, Lesson 1: Chemicals, Chemicals, Everywhere, is designed to


In the Explore phase of the module, Lesson 2: The Dose Makes the Poison, students explore the effect different doses of chemicals have on seed germination. This lesson provides a common set of experiences within which students can compare what they think about what they are observing and experiencing.

During the Explore lesson in this module, Lesson 2: The Dose Makes the Poison, students

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