'Environmental chemistry' is presented in this concise introductory text as being much more than a study of the chemical effects of pollution. Only by understanding the natural mobility of the elements and their compounds, can a true appreciation of the impact of human activities be gained. The guiding principle in the preparation of the book has been the provision of a broad survey illustrating the operation of natural systems, with some diversions to show how human activities can modify these systems. Related environmental topics are grouped together in a four-part structure and theoretical concepts are introduced as required in order to illustrate the relevance of theory to environmental problems. The first part introduces geochemical cycles and emphasises the importance of oxygen to the chemistry of reactions near the earth's surface. This importance applies to both biologically mediated and inorganic reactions, and systems, depending on these reaction types, are discussed in Parts B and C. Differences and similarities between animate and inanimate systems are reviewed, and the application of general chemical concepts to seemingly very different reactions is illustrated. In the fourth part there is a brief examination of the effects of human activities on elements that usually cycle naturally in small quantities. Also in this part, the perturbation of natural cycles by agricultural, industrial and social developments is highlighted in terms of the consequent prob Any student of the chemistry of the natural environment will find this book useful as a text, whether they be based in chemistry, environmental science, geology, physical geography, biology or ecology. Requiring a minimum of background knowledge, it is accessible to a wide readership. This book should be of interest to first and second year undergraduate students of environmental science, chemistry and ecology.