This is a well conceived and executed volume detailing in close to encyclopedic proportions the question of control of air­ borne contamination in hospital environments. Many different ap­ plication areas are described and well documented. Alternative solutions are presented in historical perspective with the neces­ sary scientific background to provide the uninitiated an oppor­ tunity to learn not only how to solve a particular problem but more critically why one solution is preferable to another. Every clinician concerned for his patients' welfare must consider the quality of the environment within the hospital--for only there is it potentially controllable Airborne dissemination of nosocomial infections are considered generally rare today. This may be the result of improved intrahospital environmental control or better infection control techniques. If one considers airborne contaminatiqn, real or potential, as undesirable within certain areas of a hospital then proper environmental control must be included in the framework of the physical and functional struc­ ture. Often it is difficult to specify which controls are needed for a specific application. Frequently this is a problem of in­ adequate knowledge of the application area and not the availability of technology. Too often, in the rush to provide a solution the newest and most sophisticated equipment is chosen, installed, and found to be more than is required for the task. To avoid these types of errors it is necessary to provide a series of alternative solutions for each problem.