ABSTRACT
Environmental science takes for its own the study of the composition of the atmosphere, water, soil, and how materials are taken up and given back by plants and animals. The objective of environmental measurements can be qualitative or quantitative. All environmental studies ultimately depend on the results of chemical analysis of samples of air, water, soil, and biological organisms. When environmental samples are analyzed, the units in which the results are expressed vary with the type of sample. The atmosphere contains just few major constituents: nitrogen, oxygen, argon, carbon dioxide, and water vapor, which varies widely. The term contaminant refers to a material which is present in a part of the environment where it is not expected. Combustion processes are one of the major sources of air contamination. Most industrial processes emit some materials to the environment. Another major contributor to environmental degradation is domestic activity, especially in areas of concentrated population.
