Great news this week on the publication of our latest paper exploring ways to improve Environmental Risk Assesses of pesticides. A thread (1/13): https://setac.onlinelibrary.wiley.com/doi/abs/10.1002/etc.4927 @etc_editor @AndreuRico3 @raqueldafouz

In this publication we explored the use of existing large chemical monitoring data sets (such as those collected under the EU’s #WFD) as a tool for retrospective risk assessment. We used data for #Chlorpyrifos in #Spain and #Portugal (2/13)

Prospective Risk Assessment, which is used for the registration of pesticides, is hard. This is because, in many cases, it is done before the compound is even used. As a result, you don’t have enough real data on exposure and potential effects. (3/13)

Models are used to predict these exposures and effects. For exposure models, it is almost impossible to model all possible landscapes, soils, use-patterns, hydrology, etc. This is especially relevant when regulating large geographical areas, such as the whole #EU.(4/13)

Retrospective Risk Assessment, on the other hand, is done for compounds which are already in use. In this case, Risk Assessors have the advantage of having real data on both effects, and concentrations of the compound in the environment. (5/13)

Using chemical monitoring datasets like those by the EU’s Water Framework Directive #WFD we can evaluate the ecological risks of current-use pesticides under large spatio-temporal scales and evaluate the protectiveness of the current prospective risk assessment framework (6/13)

In this study we looked at #Chlorpyrifos, which was recently banned for use in the #EU. Chlorpyrifos was commonly used in Mediterranean regions to protect vine, citrus and other fruit trees. Mediterranean areas, however, are very different from northern Europe. (7/13)

What we found is that during the period between 2012 and 2017, while #chlorpyrifos was approved for use in the #EU, the acute exposure Environmental Quality Standard (MAC-EQS) set by the #EU was exceeded in 2% of samples from #Spain and #Portugal. (8/13)

#Chlorpyrifos concentrations exceeded the chronic exposure Environmental Quality Standard (AA-EQS) in 18% of the samples collected in #Spain and #Portugal between 2012-2017. (9/13)

Five watersheds (all of them in Spain), as well as the complete dataset for the Iberian Peninsula showed low, but still unacceptable, levels of risk when assessed with probabilistic methods. (10/13)

Pesticide labels and the specific uses of pesticides are written and approved using prospective risk assessments based on models. If these models are correct, and the compounds are used according to the label, no exceedances of these standards should occur. (11/13)

Our data shows that these exceedances do occur. Whether the discrepancy is in the models not properly representing Mediterranean geographical and weather aspects, or whether it is a matter of product missuse is unclear. (12/13)

What is clear is that our study supports the need for further post-registration monitoring assessments with other pesticides, which can help to identify possible pesticide misuse practices and improvements of the prospective risk assessment framework. (13/13)