The three books under review represent the origins and promise of a relatively new field of study, urban environmental history. Joel Tarr's collection of previously published essays retraces the intellectual odyssey of its single most important pioneer. Concerned about contemporary pollution problems, he has spent a quarter of a century exploring the frontiers of scholarship on the relationship between cities and their technologies. In contrast, monographs by R. Bruce Stephenson and Andrew Hurley are typical of current trends to build on this foundation, enriching and broadening its parameters from a wide variety of perspectives. Here the insights of town planning and social history illuminate case studies of St Petersburg, Florida, and Gary, Indiana, respectively. Other recent works draw heavily upon the sciences, especially medicine and public health. Reversing decades of academic fragmentation – knowing more and more about less and less – the study of the urban environment is encouraging creative applications of cross-disciplinary and comparative approaches.