In pesticide registrations, terrestrial plant risk assessments are inherently conservative.  The pesticide's lowest EC25 value among = 10 test species is compared to the highest exposure estimate for a given crop use.  For protection of threatened and endangered plant species, the lowest NOAEC or EC05 value is used.  This coupling of worst-case exposure and hazard estimates is used for the assessment of both direct effects to plants and indirect effects to species relying on plants for food or habitat.  However, indirect effects to listed species are typically associated with community-based estimates rather than individual species effects, as in the case of aquatic species relying on ecosystem services provided by riparian vegetation.  In this presentation, a higher tier, statistically based risk assessment method, built on community-based estimates of relevant toxic effects, is described.  This allows for refinement of the screening level risk assessment, taking into account the complexity associated with community level effects.

Community-based approach to indirect effects assessments for terrestrial plants

244th National Meeting (2012)

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