The papers compiled here were presented at the fourth symposium in a series designed to provide a continuing introduction to current aspects of occupational safety and health. The papers represent eight topics: (1) special health programs, (2) degenerative disease and injury of the back, (3) job stress and work performance, (4) role of industry in preventive cardiology, (5) toxic compounds in industry, (6) emergency medical planning and industrial disaster, (7) industrial toxins and the community, and (8) problems in occupational health programming. Some representative titles of papers included under each of these areas consecutively are as follows: (1) How to Establish an Employee Health Service in a Reluctant Hospital; and Occupational Medical Support of a Research Hospital, (2) Examination of the Lumbosacral Spine; and Biomechanics of Manual Materials Handling and Low-Back Pain, (3) Variables in Occupational Stress; and The Stress of Relocation-Recognition and Prevention, (4) Exercise Prescription in an Industrial Fitness Program; and Cost Effectiveness in Hypertension Management, (5) Principles and Practices of Industrial Air Standards; and Contributions of the Industrial Hygienist, (6) A Pre-Triage System for Mass Casualty Care; and Electrical Injuries, (7) Arsenic Contamination Near a Copper Smelter; and The Michigan PBB Incident, and (8) The Role of Nursing in Occupational Medicine; and The Benefit-to-Risk Ratio in Occupational Health. (EM)