Ecological effect assessment by species sensitivity distribution for 38 pesticides with various modes of action

Species sensitivity distributions (SSDs) of 38 pesticides with various modes of action were analyzed as a higher-tier ecological effect assessment based on collected acute toxicity data. Then the 5% hazardous concentrations (HC5) based on each SSD were calculated as the predicted noeffect concentrations for aquatic ecosystems. The differences between HC5 and registration criteria were small (within ten-fold) for 35 of the 38 pesticides. However, there were more than tenfold differences for a fungicide and two herbicides. These results suggest that the current effect assessment scheme could underestimate the effect of such pesticides. This could be caused by differences in sensitivity of specific properties of the mode of action.

Automated summary

The study found that the predicted no-effect concentrations for the majority of pesticides were within a ten-fold difference from the registration criteria, but certain fungicides and herbicides had differences exceeding tenfold, indicating a potential underestimation of their effects by the current assessment scheme.