Ecology is a science which studies the relationship between all forms of life on our planet with its environment. This word came from the Greek "oikos" which means "home". This idea of "home" includes the whole planet of ours, its population, the nature, animals, bird, fish, insects, all other living beings and even the atmosphere around our planet. do all of them live a happy and healthy life in our Home nowadays? Unfortunately, it is nit so. Indeed, many territories, water basins, lake, rivers, seas, oceans - and the atmosphere are polluted with all kinds of technological, agricultural, chemical, nuclear and other wastes. The intensive development of sciences, industry and chemistry in the 20th century has made the pollution of our environment a global problem which should be solved by all means.