Uncertainties in risk assessments used for pesticide registrations generally lead to conservative assumptions of exposure and effects that overestimate the environmental risk.  However, the methods have also been criticized for providing insufficient protection for threatened and endangered (T&E) species.  These concerns may be addressed through collection of additional exposure and effects data to reduce uncertainty with increasing cost as the risk assessment becomes more data intensive.  However, an alternative approach is a restoration-based strategy that uses mitigation or offsets to reduce uncertainty of pesticide effects to T&E species in the context of effects from other stressors.  We present a framework that uses a quantitative scale to rank the magnitude of uncertainty in relation to factors including species’ ecology, exposure and effects data, and the relevance of the pesticide in relation to other stressors in contributing to a species’ rarity.  An overall uncertainty score is calculated and assigned a corresponding narrative risk level, from negligible to high.  The uncertainty score is incorporated into a larger uncertainty matrix that also includes a ratio estimate of geographic co-occurrence between of pesticide use and species distribution.  Based on the final ranking of a species in the matrix, an upper bound of mitigation requirements is calculated in a way that scales with the magnitude of the uncertainties.  This approach permits comparison of uncertainties across multiple species with varying life histories and pesticide exposure patterns to identify priority species for mitigation.<br/>

Decision framework for assessing pesticide effects to endangered species through mitigation actions

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.