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Introduction to Environmental Measurements
The entire world is the environmental scientist’s laboratory. 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. It examines the transport of various chemical species, elements, and compounds, among the atmosphere, the hydrosphere, the geosphere, and the biosphere. Of great importance in the development of this branch of science has been the realization that human activities are having an increasing effect, frequently not for the better, on the natural environment.
Deterioration of the environment reached significant levels with the dramatic increase in human population, accompanied by industrialization, which took place over the past century or so. Major problems brought about by these changes are the pollution of air, water, and soil; growth in the amount of hazardous waste; depletion of arable land, energy, and other natural resources; increased exposure to toxic chemicals in food, water, and air; and exposure to radiation. It was not until the 1960s that an awareness of these problems grew all over the world. Since then, a plethora of environmental regulations have been promulgated to protect our environment.
1.1Role of Measurement in Environmental Studies
All environmental studies ultimately depend on the results of chemical analysis of samples of air, water, soil, and biological organisms. Policies on reduction of pollution cannot be designed if the extent and identity of the pollutants is not known. Emissions cannot be regulated if there is no accurate and reliable method of monitoring the emitted materials. The source of such problems as global climate change can only be determined with accuracy by monitoring the concentrations of the various greenhouse gases in the atmosphere over long periods of time and at many locations, and correlating these measurements with observed temperature trends. The mathematical models constructed to predict the effect on global climate of changes in atmospheric composition are most reliable when they are tested against actual data.
Natural cycles cannot be understood if chemical compounds cannot be followed as they are passed on from air to water to soil and to the biosphere. The analytical chemist who specializes in the analysis of environmental samples is choosing to work on some of the most challenging problems in analysis, because the analytes are often present in extremely low quantities, and the matrix can be very complex. To further add to the problem, the material to be sampled is usually very non-homogeneous. The sampling of an area such as a landfill, or a constantly changing system such as a river or the ambient atmosphere requires much thought about what is to be determined and where and when samples are to be taken.
The environmental scientist or engineer may not be the person who actually does the laboratory analysis, but he or she may well be the...
