The book describes in detail about water resources storage cycling ecosystem function of marine freshwater lakes rivers and other wetlands biological and physico chemical characterizations kinds and causes of pollution and control devices. It also describes in detail the atmospheric factor air pollution due to industrial domestic and other sources global changes ozone depletion and UV-B enhancement effects and about air pollution control technologies. Soil pollution problems of solid wastes soil erosion and conservation radioactive pollution noise pollution laws and international efforts on pollution controls are described in different chapters. Important topics of current interest like biological magnification eutrophication ecotoxicology bioremediation waste-water treatment rising levels of CO2 CFCs methane and other greenhouse gases are described in detail. About the Author R. S. Ambasht Emeritus Professor INSA Senior Scientist; formerly CSIR Emeritus and INSA Hon. Scientist; Professor Head CAS Coordinator Botany Department Banaras Hindu University has taught ecology and environmental aspects for over 40 years. Decorated with Birbal Sahni Gold Medal of IBS; Platinum Jubilee Lecture Award of ISCA UGC-P; Saraswati National Award and Fellowships of the Indian National Science Academy (FNA) and the National Academy of Sciences (FNASc). He has in the past been on the Board of the International Association of Ecology; Secretary of ISTE; and President of the National Institute of Ecology; and Member of National Committee on Wetlands of the Environment Ministry. He is the author of about 175 papers several books book chapters and editor of several prestigious publications. Prof. Ambasht has chaired at top international conferences in his repeated visits to USA Canada UK Germany France Australia Japan Malaysia and Indonesia. Thirty scholars have obtained Ph.D. under his supervision. P. K. Ambasht Lecturer in Biochemistry North-Eastern Hill University Shillong is an established researcher in Enzymology in which field he has published several research and review papers in leading Indian and foreign journals. He holds B.Sc. (Hons.) M.Sc. And Ph.D. degrees of the Banaras Hindu University where h~ worked as post-doctoral UGC Research Associate in Science Faculty and as CSIR-Senior RA (Pool Scientist) in the Institute of Medical Sciences. Dr. Ambasht has also worked and published on medicinal plants of the Himalayas.