Toxic or Not Image Map


By the end of this lesson the student should be able to:

  • Summarize the flow of energy from the sun through the various levels of the food chain
  • Identify various elements of the carbon cycle, nitrogen cycle and water cycle
  • Identify the relationship of dose and toxicity to the effects of exposure from environmental hazards and the relationship of exposure, toxicity and risk

Lesson Description

This lesson defines important terms related to the environment and describes the flow of energy and matter through the environment in terms of the food chain and the carbon, nitrogen and water cycles.

Next, the lesson discusses important concepts related to the effects of hazardous substances in the environment.  It is important for the teacher to help the students understand that although there are hazards present in the environment, the effect of these hazards depends upon the toxicity of the substance and their amount of exposure.

Finally, students need to understand the relationship between the natural flow of energy and matter through the various parts of the environment and how these natural processes cause environmental hazards to spread.


There is a pre-test and a post-test for each lesson which must be printed before they are administered. Click here for the key to both tests.

Activities and Assignments

After students have read the lesson, have them work individually or in small groups on the "Slime Sleuths at Toxic Island" activity.   The activity is a mystery game where students will be asked to find out what toxic substance made the patient sick and the source of the substance.  Reading time for each lesson will vary, however, each "Slime Sleuth" activity should not take more than 20 minutes.  There is a different "Slime Sleuth" activity for each lesson, however, to encourage problem solving, the problem presented in the activity may or may not be related to the information in the lesson.  Each computer used for the lesson activity will need an Authorware web player plug-in. Click here for the plug-in.

Standards Targeted

The Texas Middle School Science and Technology Standards targeted in this lesson can be found by clicking here.

Introduction | Pre-Test | Lesson | Activity | Post-Test
PEER Curriculum | Toxic or Not Modules | Teacher's Pages | Standards