For those who are interested in understanding the critical relationship between living organisms and their environments, “Fundamentals of Ecology and Toxicology” is a vital resource. This book explores the fundamental concepts of ecology, including the significance of ecological succession, the functions of biotic and abiotic components, and ecosystem dynamics. In-depth explanations of the various biomes, ecological interactions, and the manner in which organisms adapt to their environment are provided. The book delves into the science of toxicology, which provides a comprehensive understanding of the impact of toxic substances on living organisms, in addition to ecological principles. It encompasses the biochemical and physiological mechanisms that underlie toxicity, as well as the absorption, distribution, and elimination of toxicants. The effects of pollutants, such as air and water contaminants, greenhouse gases, and the depletion of the ozone layer, are given particular attention. This book promotes an extensive understanding of environmental science by incorporating toxicology and ecology. It emphasises the necessity of safeguarding ecosystems and managing toxicants to guarantee a sustainable future. This text is a valuable resource for students and professionals in environmental science, biology, and related disciplines, as it provides practical examples and plain explanations.