Advancing surface water pesticide exposure assessments for ecosystem protection

Abstract

As the global food demand increases, the use of pesticides will continue to increase with significant growth in low- and middle-income countries. Agricultural systems in which pesticides are used are complex with significant and often unknown biological, human, and physical-chemical interactions. These interactions include climate and hydrology, soil type, selection and use of best management practices, chemical fate and transport, applicationtechnology, and land use socioeconomics. The objective of this review article is to highlight key research opportunities identified from recent special meetingsand workshops on advancing pesticide exposure assessments and mitigation. Research is needed in using advanced analytics and forensics to betterunderstand the distribution of pesticides in the environment through novel monitoring and detection. Higher-tier modeling approaches can help informmonitoring a priori to better characterize pesticide distributions in the environment. Current pesticide exposure assessments are largely focused on the fieldor watershed scale, but advancements are needed to move toward landscape-scale analyses capable of analyzing for interacting ecosystems. Assessing theeffects of complex, low-dose chemical mixtures on non-target aquatic organisms must advance with new quantitative high-throughput experimental methodsfocused on identifying interactions and not just additive effects. Field mitigation measures are currently considered as part of the pesticide exposure and riskassessment process using qualitative, fixed-efficiency type approaches, but we specifically call for the use of existing quantitative tools moving forward. Thesemechanistic modeling and simulation tools can capture the inherent complexity within an agroecological system. There is a need for risk assessment to bemore predictive of population and community-level impacts as part of environmentally relevant scenarios. Finally, it is imperative that professional societiestake a more proactive role in promoting the transdisciplinary collaboration of biological and agricultural engineers with other disciplines contributing toadvances in ecological risk assessment.