Page 184 - Materials Chemistry, Second Edition

L1644_C04.fm Page 156 Tuesday, October 21, 2003 3:13 PM

In fact, remedial actions can alter or destroy aquatic and terrestrial habitats; the
consequences of ecosystem disturbances and other ecological effects must therefore
be given adequate consideration during the corrective action response process. Thus,
it is important to integrate ecological investigation results and general concerns into
the overall site clean-up process.

4.9.7 ENVIRONMENTAL MANAGEMENT STRATEGIES
Environmental pollution problems have reached an important level in most societies
globally because pollution through chemicals represents a significant portion of the
overall problem of environmental protection. The effective management of environ-
mental pollution problems has certainly become an important environmental priority
that will remain a growing social concern for next future. This is mainly because of
the numerous complexities and inherent uncertainties involved in the analysis of
such problems.
Whatever the cause of an environmental pollution problem, the impacted media
must be remedied. However, restoration or clean-up may not be economically or
technically feasible. In this case, risk assessment and monitoring the situation,
together with institutional control measures, may be acceptable risk management
strategies in lieu of remediation.
Overall, a risk assessment will generally provide the decision maker with sci-
entifically defensible procedures for determining whether a potential environmental
pollution problem could represent a significant adverse health effect, and environ-
mental pollution problems could represent a significant adverse candidate for miti-
gative actions. In fact, the use of health and environmental risk assessments in
environmental management decisions in particular, and a corrective actions program
in general, is becoming an important regulatory requirement in several places. For
instance, a number of environmental regulations and laws in various jurisdictions
increasingly require risk-based approaches in determining clean-up goals and related
decision parameters.

4.10 EXAMPLE: COMPARISON OF TWO FATE AND
EXPOSURE MODELS

The choice of which model must be used for an application is a big issue. Next we
will present two different models, EUSES and CalTOX, and explain how differently
they work. EUSES has been developed in Europe to assess the risk of new or existing
chemicals produced and CalTOX was released by the California EPA as a tool to
assist in health-risk assessment. They differ significantly in their functional proper-
ties and limits, necessary inputs and results. Figure 4.11 shows a screen shot of
EUSES depicting the typical outline section and an opened data input window.
Figure 4.12 shows a screen shot of the Excel spreadsheet with the input and output
sections of CalTOX.
An important point is the input data (physical, chemical, toxicological and other
properties of the contaminant) that the models need for calculation. Figure 4.13
depicts the amount of exclusive inputs of CalTOX and EUSES. The input data

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