This book provides a brief introduction to the chemistry of the elements, in particular the mainly inorganic compounds which are involved in natural biogeochemical cycles, and a discussion of the disruptions caused by man to these cycles. It assumes only GCSE-level chemistry. This new edition includes a fuller treatment of ozone depletion, the greenhouse effect caused by an increase in carbon dioxide in the atmosphere, the various reactive species of nitrogen in the troposphere and pollution of water caused by nitrates from fertilizers. In addition a new chapter deals with organic compounds which are dangerous, such as PCBs and dioxins, some herbicides and pesticides. Material is presented element by element and a four-part format is used, allowing the grouping together of related environmental topics and the introduction of theoretical concepts as required. Part A provides an introduction to many of the essential basic geological, geochemical and chemical ideas. Since oxygen is involved in most reactions occurring near the Earth's surface, this element is discussed first. Its importance is evident in both biologically mediated and inorganic reactions. Systems dependent upon 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 apparently very different reactions is illustrated. In part D 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 problems of environmental management.