QUALITATIVE ANALYSIS OF THE MOST LOCALLY RELEVANT RUNOFF AND EROSION PARAMETERS FOR CONSTRUCTING BRAZILIAN SCENARIOS.

Estimating exposure is one of the most important steps in an environmental risk analysis of crop protection products to non-target organisms. Regulatory agencies like the USEPA, PMRA and EFSA all use mathematical exposure models in their regulatory assessment process. Brazil has been discussing the adoption of Pesticide in Water Calculator (PWC) to be applied in aquatic pesticide risk assessment. Therefore, a qualitative sensitivity analysis (Morris OAT method) was performed to understand which are the most important local parameters in the PWC to estimate environmental concentrations in surface water (EEC SW ). In addition, an exercise comprising two corn scenarios in two regions in Brazil was developed (UDI and ARA). Two herbicides with different soil binding properties and modes of action were selected to estimate the EEC SW . The results showed that the parameters of importance were different for each site, probably due to different soil characteristics and meteorological patterns. This outcome suggests that regulatory agencies should consider developing more than one scenario to account for different agricultural regions. For Herbicide 1, the EEC SW for UDI were similar to US scenarios, while for ARA they were lower. For Herbicide 2, the EEC SW for the UDI site was higher than most of the US scenarios, while at the ARA site, EECs were similar to 4 US scenarios and lower than the other 6. Local data were used as a refinement, resulting in the decrease of the EEC SW s for both herbicides in the UDI site. For the ARA site, Herbicide 1 displayed a similar EEC SW value, while for Herbicide 2, it was lower after the refinement. Overall, these results demonstrated the importance of developing local scenarios to provide more realism to estimate pesticide exposure from its agricultural use and may help regulators to make decisions and recommend mitigations regarding the use of crop protection products. This article is protected by copyright. All rights reserved. Integr Environ Assess Manag 2023;00:0-0. © 2023 SETAC.