Evaluation of two indicators according to the objectives of the Sustainable Use of pesticides Directive (SUD). A French case study

The European agricultural protests of 2023/2024 have prompted a reassessment of public policies at the EU level with the SUR put on a stand still. In France, in early 2024, the government replaced the historical monitoring indicator "NoDU'' with the European Harmonized Risk Indicator HRI1 to monitor the progress in the use of Plant Protection Products (PPP) in its National Action Plan (NAP). This study aimed to assess the relevance of these two indicators regarding the objectives outlined in the Sustainable Use of pesticides Directive (“SUD”) that defines the framework within which they operate. To this effect, we analyzed the PPPs they consider, the official calculation formulas, but also their past evolution and possible future evolutions through putative scenarios of changes in PPP use and regulation: ban or not; substitution or not; for the top 5 synthetic insecticides; all synthetic insecticides; glyphosate; mancozeb; and the top five active ingredients from HRI1 risk group 3 (candidates for substitution). French PPP sales data from 2011 to 2021 were used for past evolutions and we used the last available figures in France, 2021, for simulations. Designed to monitor the use of PPPs by farmers, the NoDU mostly monitors achievement with regards to one aim of the SUD: to "reduce dependency on the use of pesticides" and promote "the use of Integrated Pest Management". Its value does not change with the mere substitution of a product by another, even if the second is deemed less toxic. This limits its ability to assess the "risks and impacts of pesticide use on human health and the environment", the first aim of the directive. The HRI1 indicator is not supposed to strictly quantify the use of PPP and was found to inadequately reflect significant changes in PPP use, but also in the induced risk: 1) changes of use without a ban on a substance are limited and as such, past correlation of HRI1 with the QAI of the fourth group (banned PPPs) is very high (0.90); 2) the im