Ecotoxicological modeling would not always benefit a risk assessment. For example, assessment of effects above the level of individual-organism endpoints is unnecessary when a worst-case analysis using individual-level endpoints shows that the risk is negligible. In worst-case analyses, endpoints should be carefully chosen to include potential sublethal effects on organisms, and the risk estimates should be interpreted conservatively. This approach minimizes the chance of missing cases where individual-level effects have impacts on the population or higher levels.
Higher-level endpoints are also not needed if an initial assessment shows, for example, that available evidence from quantitative field studies documents severe effects of chemical contaminants on the abundance of target species. Thus, ecotoxicological models may not be needed for a baseline risk assessment. In cleanup programs, however, such models may still prove useful for evaluating the mechanisms of population-level effects (i.e., which vital rate is affected or if indirect effects mediated through trophic interactions are likely), which would aid in designing remedial actions.
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