Data to assess pesticide exposure in soil and water are scarce and unevenly distributed in Latin America, especially due to the size of the region and the vast agricultural landscape. This makes it difficult to assess associated environmental risks. We suggest that the lack of pesticide exposure or monitoring data can be addressed by using validated models to provide estimated pesticide exposure concentrations in soil and water bodies. This exposure modeling approach has been used by regulatory agencies in other countries and regions such as the United States, Canada, and the European Union. In order to properly estimate pesticide exposure concentrations, we advocate for the development of local scenarios containing local weather, soil, and crop data to be used in the existing models. A sensitivity analysis of the models can be performed to determine parameters that are sensitive and therefore inputs to these parameters are derived locally. We believe the development of local scenarios in the region is attainable and can be a pragmatic approach for developing a more comprehensive picture of potential pesticide exposure in the region. Integr Environ Assess Manag 2021;17:901–904. © 2021 Syngenta Proteção de Cultivos Ltda

The current pesticide registration process in Brazil is mainly hazard-based and does not consider exposure and therefore risk. However, the scenario prompted changes and discussions about risk assessments by Brazilian environmental regulatory agencies. The US Environmental Protection Agency's (EPA) Pesticide in Water Calculator (PWC) model is used as a regulatory tool for aquatic exposure assessment in Canada and the USA for exposure evaluation of agrochemical products; nevertheless, the available scenarios only consider North American local conditions. This work aims to demonstrate a parametrization of the PWC model for a Brazilian scenario, considering the active ingredient glyphosate and sugarcane agronomic practices. The estimated environmental concentrations (EECs) obtained were compared with two standard EPA scenarios. Essential parameter data to build a specific local scenario were collected from the literature and official Brazilian databases. The EECs (1-in-10 years) of glyphosate according to the conditions established were 1.427 μg L −1 (1st day), 0.382 µg L −1 (21st day), and 0.2027 µg L −1 (60th day). These values can be used as exposure elements in acute and chronic risk assessments considering the agricultural practices used in the developed scenario. A 4.45-fold and 1.28-fold difference was found comparing the 1-day (1-in-10 years) average concentration of the Brazilian scenario with two EPA standard scenarios. Such a difference may affect the outcome of risk assessments, affecting regulatory decisions. This demonstrates the importance of generating more realistic scenarios for Brazil, yielding surface water EECs that consider local conditions.

Estimating exposure is one of the most important steps in an environmental risk analysis of crop‐protection products to nontarget organisms. Regulatory agencies such as the US Environmental Protection Agency (USEPA), Pest Management Regulatory Agency (PMRA), and European Food Safety Authority (EFSA) all use mathematical exposure models in their regulatory assessment process. Brazil has been discussing the adoption of the 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 (EECSW). In addition, an exercise made up of two corn scenarios in two Brazilian regions was developed (Uberlândia [UDI] and Arapoti [ARA]). Two herbicides with different soil‐binding properties and modes of action were selected to estimate the EECSW. The results demonstrated that the parameters of importance were different for each site, probably the result of 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 EECSW for UDI were similar to US scenarios, whereas for ARA they were lower. For Herbicide 2, the EECSW for the UDI site was higher than most of the US scenarios, whereas at the ARA site, EECs were similar to four US scenarios and lower than the other six. Local data were used as a refinement, resulting in the decrease in the EECSW for both herbicides in the UDI site. For the ARA site, Herbicide 1 displayed a similar EECSW value, whereas 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 determine and recommend mitigations regarding the use of crop‐protection products. Integr Environ Assess Manag 2023;00:1–11. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).