Sixth in a series of congressionally mandated studies, this book is an updated review and evaluation of the available evidence regarding the statistical assoication between exposure to herbicides used in Vietnam and various adverse health outcomes suspected to be linked with such exposure. This book builds upon the information contained in the earlier books in the series: *Veterans and Agent Orange: Health Effects of Herbicides Used in Vietnam (1994) * Veterans and Agent Orange: Update 1996 * Veterans and Agent Orange: Update 1998 * Veterans and Agent Orange: Update 2000 * Veterans and Agent Orange: Update 2002 * Veterans and Agent Orange: Herbicides and Dioxin Exposure and Type 2 Diabetes (2000) * Veterans and Agent Orange: Herbicide/Dioxin Exposure and Acute Myelogenous Leukemia in the Children of Vietnam Veterans (2002) Veterans and Agent Orange: Update 2004 focuses primarily on scientific studies and other information developed since the release of these earlier books. The previous volumes have noted that sufficient evidence exists to link chronic lymphocytic leukemia, soft-tissue sarcoma, non-Hodgkin's lymphoma, Hodgkin's disease, and chloracne with exposure. The books also noted that there is "limited or suggestive" evidence of an association between exposure and respiratory cancers, prostate cancer, multiple myeloma, the metabolic disorder porphyria cutanea tarda, early-onset transient peripheral neuropathies, Type 2 diabetes, and the congenital birth defect spinal bifida in veterans' children. This volume will be critically important to both policymakers and physicians in the federal government, Vietnam veterans and their families, veterans' organizations, researchers, and health professionals.