Hydrogen sulphide (H2S) is a colourless gas which occurs naturally in some environments such as sulphur springs, swamps and salt marshes, and is often associated with the decomposition of organic material. In this book, the authors present research on the sources, detection and health hazards of hydrogen sulphide. Topics discussed include the methods of detecting hydrogen sulphide in the environment; technologies for hydrogen sulphide removal; and oral disease and hydrogen sulphide production by oral bacteria.