Monday, August 14, 2023, 9:50 - 10:15AM, Room 3016, West Bldg. (Moscone Center)

Title: What is the appropriate sampling frequency necessary for pesticide monitoring programs in flowing surface waters? An analysis using SEAWAVE-QEX. Andy Jacobson, Presenter; Zechariah Stone; Brenna Kent; Richard Brain

Abstract: Surface water monitoring data can be invaluable for regulatory exposure assessments of pesticides as it provides context/comparison for modeled/predicted exposures. In 2019, the United States Environmental Protection Agency (USEPA) published a white paper which presented tools to quantitatively assess water monitoring data for pesticide risk assessment. Among these was the Seasonal Wave with Streamflow Adjustment with Extended Capability (SEAWAVE-QEX) model, which is a time-series model developed by the United States Geological Survey (USGS) to simulate daily pesticide concentrations in surface water using existing, non-daily monitoring data, seasonal patterns, and daily streamflow. Due to the considerable monetary costs and logistical challenges of water quality monitoring programs, including sample collection and analytical chemistry, an analysis was conducted to determine the appropriate sampling frequency, utilized in-conjunction with SEAWAVE-QEX, to accurately estimate pesticide exposures in flowing surface water. To conduct this analysis, daily monitoring data collected from watersheds in the Atrazine Ecological Monitoring Program (AEMP) were subsampled at various intervals (4-day, 7-day, 14-day, and 30-day) to evaluate the predictive performance of utilizing monitoring data collected at each sample frequency interval. The primary objective of this work is to determine the appropriate sampling frequency of pesticide monitoring data to accurately estimate exposures in flowing surface waters and ultimately inform monitoring program design and reduce the associated costs of future programs, including the continuation of the AEMP. Another objective is to demonstrate that monitoring data collected at less frequent sampling intervals is still more accurate than the USEPA’s Pesticide Water Calculator (PWC) at estimating pesticide exposures, and therefore should be utilized in national pesticide exposure assessments when available and appropriate.

Monday, August 14, 2023, 4:40-5:05PM, Room 3014, West Bldg. (Moscone Center)

Title: Inventory and review of existing agricultural best management practices for pesticides in the USA. Andy Jacobson, Presenter; Nick Guth; Zechariah Stone; Dean Desmarteau; Richard Brain

Abstract: As part of the U.S. Environmental Protection Agency’s (EPA) updated 2022 Endangered Species Act (ESA) workplan, Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Interim Ecological Mitigation, the Agency has proposed a picklist approach of runoff mitigation measures to protect listed species identified as potentially at risk from predicted pesticide exposure based on a screening-level risk assessment approach. However, it is unclear how effective the proposed mitigations are, how feasibly they can be implemented, and/or how likely they are to be adopted. A screening level risk assessment is insufficient to inform on the necessity for mitigation, and incomplete knowledge of picklist implications introduces uncertainty regarding their effectiveness to ameliorate potential risks identified under this paradigm. Moreover, this proposed process adds considerable uncertainty for growers.

To evaluate the potential ramifications of picklist mitigation measures proposed by the EPA, a database was developed to inventory existing, implemented agricultural Best Management Practices (BMPs) for pesticide runoff in the contiguous US. Sources of this database encompass management practices funded by both federal and state government agencies, including departments of agriculture and conservation. In addition, the feasibility and viability of picklist mitigation measures, which may vary due to underlying environmental conditions such as soil type, slope, land use, geographical region, and other characteristics, were evaluated. A webtool was also created to allow users to query the BMP database and map query results in relation to relevant spatial layers for endangered species’ ranges and critical habitats. Ultimately, the objectives of this work are to support refinement of the endangered species assessment process for pesticides by inventorying the existing agricultural BMPs, evaluating the potential ramifications of picklist mitigation measures proposed by the EPA, and to provide feasible BMP recommendations to farmers to support compliance with the ESA.

Monday, August 14, 2023, 4:05-5:30PM, Room 3022, West Bldg. (Moscone Center)

Title: Climate change and agriculture: AGRO’s role in ensuring sustainable agriculture. Heidi Irrig, Presenter; Pamela Rice; Amy Ritter

Abstract:The chemists and scientists who comprise the American Chemical Society (ACS), Agrochemical Division (AGRO), are consciously addressing issues facing our world and its climate. In 2015 the United Nations (UN) established 17 Sustainable Development Goals (SDG) to protect the planet and improve the lives of everyone around the planet. SDG 13: “Take urgent action to combat climate change and its impacts”, will be reviewed and the current role AGRO has in addressing this goal. The evolution of AGRO meeting topics and leadership collaboration with other ACS Division will be assessed in the context of this goal. AGRO has brought complex science topics to the forefront for discussion and consideration amongst a wide variety of industry, academic and government experts for assessment. Addressing the development and use of agricultural products and technologies to ensure agricultural productivity and sustainability amongst potential climate change is a particularly relevant topic for consideration. AGRO provides a neutral forum for the various agricultural and chemical sections to evaluate the current situation and develop plans to have a positive impact on the changing world climate.