This book presents comprehensive reviews on the latest developments of nanotechnologies to detect and remove pollutants in water, air and food. Polymer nanocomposites, nanoparticles from microbes and application of nanotechnologies for desalination and agriculture are also addressed. Pollution of water and air by contaminants and diseases is a major health issue leading globally to millions of deaths yearly, according to the World Health Organization, and such an issue requires advanced methods to clean environmental media.