Sampling Task

Collecting truly representative samples from the natural environment is no simple task. The natural environment is both complex and heterogeneous, comprising a multitude of matrices (air, water, soil, sediment, biota), each with associated difficulties and potential sampling approaches. The concentrations of contaminants are usually nonuniform in space and over time and this adds to the complexities in sampling. In addition, the boundaries of the environment being sampled may not be sharply defined or indeed visible; the material sampled will rarely, if ever, be strictly uniform, and in many cases the properties of interest, for example, trace concentrations of contaminants, can be lost or at least altered in the sampling process through reactions with other components of the sample or with the materials used to collect and store the samples. All too often, conclusions based on laboratory results from the most careful analysis of the chemical and other properties of environmental samples are invalidated because the original collection of the environmental samples was inadequate or invalid.

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