Over two billion people live in tropical lands. Most of them live in intimate contact with the immediate environment geological, obtaining their food and water directly from it. The geochemistry of these unique tropical environments have a marked influence on their health, giving rise to diseases that affect millions of people. The origin of these diseases is geological as evidenced by the dental and skeletal fluorosis, iodine deficiency, trace element imbalances to name a few. This book, one of the first of its kind, provides an excellent introduction to the emerging discipline of Medical Geology.