This book is intended to present an integrated approach to the geochemistry of the earths surface, including topics ranging from environmental contamination of air, water and soil to natural processes such as chemical weathering, carbonate equilibria and sediment diagenesis. The title, Geochemistry of Environmental Systems, is intended to emphasize coverage of natural and anthropogenic controls on the composition of systems ranging from atmospheric and aquatic to soils and sediments. While there are many textbooks that cover various aspects of geochemistry, no book covers the full range of topics presented here. Although primarily focused on inorganic geochemistry, this book will also present a synthesis of important processes, concepts and topics in organic environmental chemistry and biochemistry, and emphasize relationships among inorganic, organic and biochemical systems embodied in cycling of elements such as C and N.  Another notable feature of this book is the way in which it will incorporate case studies with a global perspective published in journals such as Chemical Geology, Geological Society of America Bulletin, Ground Water, and Environmental Science and Technology (and the many other related journals in this broad field the approach will be modelled after the way that Drever and Ruddiman bring current research and journal publications into their texts). This approach is intended to (a) introduce students to current advances and applications of the materials they are learning, (b) highlight certain topics of interest in a hands-on manner, and (c) present pertinent references (from recent articles to classic, fundamental papers) that will point the student and professor in the direction of more detailed, in-depth treatments of topics. Case studies will be selected so as to present coverage of topics on a global/international scale The book also will present quantitative approaches necessary to teach these topics in an upper-level undergraduate and graduate level environmental geochemistry class, but most will be back-of-the-envelope style calculations that are mainly algebraic, and occasionally calculus-based.  Various types of instrumental analysis will also be presented so that students can understand how data used in geochemistry are collected and analyzedexamples include XRD in mineralogical studies, GFAA, ICP-MS and ICP-AES in rock, soil and water chemical analysis, chromatography in organic and dissolved anion analysis, mass spectrometry in isotope analysis, and electron microprobe analysis (EMPA) for nano-scale studies of solids.