Laboratory and experimental findings are probed to determine how and to what degree different immunotoxicants have induced clinical disease. Citations of animal research are restricted to those studies that point the way for future human studies, or have direct relevance to human situations. To further the reader's understanding of xenobiotics, the authors treat the subject of purposeful immunomodulation, achieved by administering immunosuppressive or immunopotentiating drugs. Despite increasing public awareness, there remains an inaccurate perception of what chemicals can and cannot do. This important reference sets the record straight, making it an essential source for toxicologists, immunologists, industrial hygienists, microbiologists, allergists, as well as all professionals in the agricultural and cosmetic industries, and those involved in chemical and biological regulation.