Statistically-Based Soil-Climate Exposure Scenarios for Aquatic Pesticide Fate Modelling and Exposure Assessment in the Pampa Region of Argentina

MARÍA FLORENCIA DANDREA; CECILIA DIP; BRODEUR, JULIE CÉLINE

Congreso; SETAC LatinAmerica 14th Biannual Meeting; 2021

Although pesticides are intensively employed in the Pampa region of Argentina, the possibility to perform environmental risk assessment (ERA) remains limited due to the absence of readily available databases to run pesticide fate models and the lack of standardized realistic worst case scenarios. The aim of the current study was to further advance capacities for performing probabilistic ERA in the Pampa region by dividing and parameterizing the region into functional soil-climate mapping units (SCU) and defining statistically-based worst-case soil-climate exposure scenarios. Results obtained demonstrated that the SCU selected for a specific modelling exercise should depend on the dissociation constant (Kd) of the pesticide evaluated and whether short-term or long-term pesticide fate modeling and risk assessment is required. Four regionally representative SCUs were specifically identified for modelling the fate of pesticides with low, high and intermediate values of Kd. Fate modeling of pesticides with an intermediate Kd requires the use of a different SCU for short-term versus long-term pesticide modelling, whereas this distinction is not necessary in the case of pesticides with both low and high Kd. The current definition of realistic worst-case soil-climate scenarios represents a crucial step towards better pesticide fate modeling and risk assessment in the highly agricultural in the Pampa region of Argentina.