This unit of instruction for grades 4-6 is one of a series of curriculum units referred to as the Interdisciplinary Unit. Its purpose is to allow the individual teacher to expose the students to many experiences, ideas, and applications based on their environment (Kentucky). Each lesson is built on two basic concepts, each to balance the other. One concept is a positive statement and the other, its opposite. Each lesson has behavioral objectives and is developed in a three part sequence--showing, discussing, and applying the ideas and concepts of that lesson. The unit is considered as a model on which to build and expand, both for teachers and students. The basic concepts presented in this unit include air, water, land use, noise, and population. (EB)