Teratology is at once among the oldest and youngest of human preoccupations. Coincident with man's first observations of the stars were his recordings of human and animal deformities. But, such aberrancies must have occurred even earlier, for although it is one of those things-like evolution-that cannot be proven, it is nevertheless indisputable that dysmorphogenesis must have occurred from the time complex forms of life first arose on our planet; and that from the beginnings of human awareness our species was conscious of such happenings. From the earliest recordings of this fascination with the form and meaning of abnormality a tortuous but continuous line extends to modern struggles to understand and control these manifestations. And now, after long occupying an honorable but peripheral place in the halls of philosophical and scientific pursuits, teratology has quite suddenly come to take a prominent position at the hub of a complex crossroads of human concerns. This shift in its fortune has taken several forms. Fetal maldevelopment has become the concern of environmentalists, activists of various persuasions, indus trial organizations, government agencies, ethicists, parents-i. e. , individuals and groups whose actions are impelled by apprehension. Such motives are of course not without basis; the trauma of thalidomide left a scar yet raw. For still others clinicians, academics, experimentalists-the upsurge in the interest in fetal mal development is at a different level, and their pursuits are broad, taking external agents as but one of the causes of defective development.

Why Efforts to Expand the Meaning of "Teratogen" Are Unacceptable Disagreement about nomenclature in teratology is not new. Dissent even about the very fabric of the discipline-what congenital malformations consist of-has often been voiced. Time, instead of resolving such diffi culties, has sometimes worsened them. For example, in the past it was agreed that congenital malforma tions are abnormalities of structure present at birth, but differences of opinion concerning where the line between normal and abnormal was to be drawn prevailed. It was obvious that, in order to discover the causes of congenital malformations and cast strategies for their prevention, it would be necessary to have knowledge of the baseline of their frequency, and that this required uniformity of definition of terms. Since malfor mations of primary social concern are those having grave outcomes (and are, paradoxically, also the commonest ones), it is logical that such condi tions were the first consideration of investigators and were the defects whose frequency was considered to comprise the required baseline.

Links information on experimental teratogenic agents with the congenital defects in human beings.

This book is an an up-to-date survey and summary of present knowledge and future expectations regarding the environmental causes of congenital malformations in human beings, beginning with the earliest discoveries of the 20th century up to the latest ideas and problems at its end, presents views and comments on the progress made over the century in understanding human prenatal maldevelopment.

The study of birth defects has assumed an importance even greater now than in the past because mortality rates attributed to congenital anomalies have declined far less than those for other causes of death, such as infectious and nutritional diseases. It is estimated that as many as 50% of all pregnancies terminate as miscarriages. In the majority of cases this is the result of faulty development. Major congenital malformations are found in at least 2% of all liveborn infants, and 22% of all stillbirths and infant deaths are associated with severe congenital anomalies. Teratological studies of an experimental nature are neither ethical nor justifiable in humans. Numerous investigations have been carried out in laboratory animals and other experimental models in order to improve our understanding of abnormal intra-uterine development. In less than two decades the field of experimental teratology has advanced phenomenally. As a result of the wide range of information that is now accumulating, it has become possible to obtain an insight into the causes, mechanisms and prevention of birth defects. However, considerable work will be needed before these problems can be resolved. This book brings together some of the more recent and important research findings related to the mechanisms and pathogenesis of abnormal develop ment. It is not only a documentation of the latest experimental work, but it also points out future directions that seem productive and challenging.

The Handbook of Pesticide Toxicology is a comprehensive, two-volume reference guide to the properties, effects, and regulation of pesticides that provides the latest and most complete information to researchers investigating the environmental, agricultural, veterinary, and human-health impacts of pesticide use. Written by international experts from academia, government, and the private sector, the Handbook of Pesticide Toxicology is an in-depth examination of critical issues related to the need for, use of, and nature of chemicals used in modern pest management. This updated 3e carries on the book's tradition of serving as the definitive reference on pesticide toxicology and recognizes the seminal contribution of Wayland J. Hayes, Jr., co-Editor of the first edition. - Presents a comprehensive look at all aspects of pesticide toxicology in one reference work. - Clear exposition of hazard identification and dose response relationships in each chapter featuring pesticide agents and actions - All major classes of pesticide considered - Different routes of exposure critically evaluated

First Published in 1986, this two-volume set explores the methods of toxicological risk assessment. Carefully compiled and filled with a vast repertoire of notes, diagrams, and references this book serves as a useful reference for toxicologists and other practitioners in their respective fields.