Stressors and Soil Contamination - Sustainable Practices in Geoenvironmental Engineering - page 31

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Stressors a nd Soil Contamination
2.1 Introduction
Two of the most important ecosystem components of the geoenvironment are soil and
water. These two components, together with the atmospheric component provide almost
all of the necessary elements needed to support life for all living species. This chapter
focuses on the soil ecosystem component and the problem of stressor impacts on this com-
ponent. The next chapter will pay similar attention to the water ecosystem component of
the geoenvironment.
2.2 Stressors and Impacts
As pointed out in Chapter 1, almost any thing that happens (i.e., any input or any activity in
the ecosphere) will result in the product of some kind of stressor-related impact on the geo-
environmental landscape and its associated ecosystems. To protect the status and manage
the geoenvironment, the nature of these impacts and whether these impacts will add value
to the particular ecosystem—or subtract from the functionality of that particular ecosystem
in the geoenvironment—needs to be determined and better understood. A complete listing
of all the impacts on the ecosystems of the geoenvironment is not possible because we are
not sure if we are fully aware of all the kinds of activities and interactions that are active in
a functioning ecosystem. As previously deined, a functioning ecosystem includes not only the
biological and chemical activities in the ecosystem, but also the physicochemical, mechani-
cal, hydraulic, and thermal interactions that are characteristic of the type of ecosystem under
consideration. With our present understanding of the geoenvironment and the associated
functioning ecosystems, it is dificult (and virtually impossible) to fully catalogue all of these
activities and interactions. What is possible at this stage is to examine and determine how
the known activities and interactions are affected or changed because of the stresses, distur-
bances, alterations, etc., to the ecosystem of interest.
The major sources of impacts and the resultant nature of the impacts cannot be easily
listed without speciication of targets of the impacts. Some of these sources may not be
immediately evident, and some of the impacts will not be readily perceived or understood—
because the effects of the impacts may not be apparent and/or because the effects or results
of the impacts cannot be readily recognized. A simple case in point is the effect of buried
toxic substances in the ground on human health—particularly if the impact on the health of
those that come in contact with the material is mutagenic or teratogenic.
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