The objective of this set of investigations is to start with the problems that beset us in our use of the environment and, through these, to move towards a better understanding of the principles which regulate life on this planet. The packs, or units, are concerned with a number of topics of environmental importance, each of which deals with some aspect of the ecological balance of the human environment. Each is linked with the others to form a reasonably comprehensive view of man's relationship with his physical and biological environment. Topics and sub-topics are presented in six categories: population, food supply (including quality and factory farming), land use (including leisure), conservation of natural resources (recycling, water, energy, wildlife, natural beauty, soil), pollution, and man and his environment. Material in the individual topics covers (1) the importance of the topic, (2) some of the problems associated with the area of study, particularly with regards to values, (3) an outline of the subject, its scope and content, (4) some investigations or learning activities, and (5) links, or how the problems and topics are interrelated. The work was developed for the Schools Council "Project Environment." (BL)