This book looks at genotoxicity which is a deleterious action on cell genetic material affecting its integrity. Genotoxic substances are known to be potentially mutagenic or carcinogenic, specifically those capable of causing genetic mutation and of contributing to the development of tumours. In humans, DNA damage or genotoxicity may be caused by exposure to outside agents like radiation, pesticides, combustion of hydrocarbon products as well as antineoplastic drugs. DNA damage could also come from inside of the body, determined mainly by excessive free radical production generated by some disease process. The importance then, is to identify the genotoxity and try to protect the body, which may be as simple as removing the source of exposure or providing protection against such agents. This new important book gathers the latest research from around the globe in this dynamic field of study.