Environmental Analysis Tools - Environmental Impact Analysis: Process and Methods - page 265

- A wealth of toxicological research data and funds are available
for new research, but only limited data and funds available for
ecological response to toxic chemicals.
- Assessments end with evaluation of health effects to individu-
als, whereas the broader community aspects (e.g., continued sur-
vival of population, ecological process, and habitat suitability)
are under consideration for ecological assessment.
- Tests of site contaminants on receptors are unethical and not
permitted, but laboratory exposure of site media to ecological
receptors is a key component of the ecological risk assessment.
r Environmental impact analysis compared with ecological risk
assessment:
- Changes (e.g., impacts) must be predicted as opposed to the

effects already in place

- A multitude of receptors as opposed to a limited set

- A stand-alone description and justification for the decision

regarding the proposed action, whereas the ecological risk
assessment is just one component in the ultimate cleanup and
remediation decision

- There is always the possible decision to do nothing or select the no-

action alternative as opposed to the mandate for action if risk exists

- Stakeholder involvement is a combination of technical and social

input, but risk assessment stakeholders are primarily highly
technical in the fields of ecology or toxicology.

Similar to environmental impact analysis, there is an overall framework for
ecological risk assessment (Figure 7.1) and then specific tools and methods
can be applied within the framework. This framework can also be presented
in a simplified, conceptual form (Figure 7.2) similar to the environmental
impact analysis credit card diagram depicting impact as a function of the
affected environment and the alternatives (Figure 4.1). There is no firm set
framework for ecological risk assessment and different regulatory programs
(U.S. EPA 1997 and 1998), types of sites, and preferences of the ecological risk
assessment practitioners result in a number of variations. But most variations
consist of a number of sequential steps and include some expression of the
steps discussed in this chapter and illustrated in Figure 7.1. All of the accepted
ecological risk assessment approaches include an initial evaluation (screening-
level risk assessment) that is analogous to the National Environmental Policy
Act (NEPA) environmental assessment (see Section 3.1.4) because both deter-
mine the need for additional analysis to determine the level of effects. Each of
the individual steps in the ecological risk assessment process is summarized
under a separate heading, followed by a description of critical scientific inves-
tigation tools available for ecological risk assessment.