This book focuses on the impact of environmental chemicals on human health. Its coverage includes metals contaminating the environment, persistent organic pollutants (POPs), air pollution and endocrine disruptors. Harmful consumer products, workplace exposure, cosmetics, microplastic waste are described.  Since most chemical substances are related to degenerative disorders and other communicable diseases, the proposed models of disease are analyzed, including cancer and psychiatry disorders. To provide an understanding of the mechanisms of diseases due to exposure, the book also covers basic background knowledge in genetics and epigenetic mechanisms. Oxidative stress and antioxidant mechanisms of the body are presented and how chronic inflammation and oxidative stress leads to disease. Finally, the role of a well-balanced diet and ingredients in the diet which prevent disease as well as the mechanisms of prevention are emphasized.