Pollution is the introduction of contaminants into an environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances, or energy, such as noise, heat, or light. Pollutants, the elements of pollution, can be foreign substances or energies, or naturally occurring; when naturally occurring, they are considered contaminants when they exceed natural levels. This book reviews research on global pollution control including organic waste valorisation in agriculture and its environmental risk implications, natural and anthropic stressors on freshwater decapod crustaceans, and others.