SusChEM: Collaborative Research: Environmental Fate and Effects of Dichloroacetamide Safeners: An Overlooked Class of Emerging Contaminants?

PI名称：John sivey提案号：1703796许多用于农田的除草剂配方都含有安全剂。安全剂是所谓的“惰性”成分，添加它是为了保护作物（而不是杂草）免受除草剂可能造成的损害。安全剂的施用量与许多除草剂活性成分相当；然而，与大多数除草剂活性成分不同，安全剂的环境命运和影响尚不清楚。该项目的目的是解决与一类主要安全剂的环境命运和生态影响有关的广泛知识差距。这个合作项目联合了一个多学科的专家和学生团队，他们来自一个主要的本科机构（陶森大学）和一个博士授予机构（爱荷华大学），目的是促进与安全剂使用相关的可持续农业实践。本项目旨在促进我们对二氯乙酰胺安全剂及其转化产物的环境持久性和生态毒理学风险的理解。尽管被归类为“惰性”，但安全剂具有生物活性，预计其生物活性将通过选定的环境转化（包括光解和还原性脱氯）增加。由于它们的广泛使用，安全剂可能代表了一类被忽视的新兴污染物。利用商业安全剂及其除草共剂，该项目将(1)确定它们在地表水中的光化学转化速率和机制；(2)量化它们在模拟饮用水处理过程中的去除和/或转化程度；(3)建立与其生物转化相关的时间尺度；(4)识别这些转化的产物，包括反应如何改变手性安全剂的对映体特征；(5)评价安全剂及其转化产物对非靶水生生物的生态毒理学风险。商业配方可包括与消旋安全剂混合物共配制的对映异构体富集除草剂。因此，实验将包括单个安全剂对映体，安全剂外消旋体，安全剂+除草剂的二元混合物，代表商业配方。由于安全剂的使用预计将在未来增加，因此迫切需要获得可靠的该类化学品的环境评价数据。该项目将提供一些必要的第一批非工业数据，以评估天然和工程水生系统中与安全剂有关的持久性和风险。此外，由于二氯乙酰胺安全剂广泛应用于用于食品、动物饲料和生物燃料生产的玉米，这项工作面临着食物-能源-水关系可持续发展的挑战。随着社会越来越依赖农业化学的进步来养活不断膨胀的人口，这项工作通过指导环境友好的安全配方的设计来促进可持续农业。该项目的核心是陶森大学和爱荷华大学之间的研究伙伴关系。这种伙伴关系的一个标志性努力是本科生参加爱荷华大学的夏季研究机会计划（SROP）。SROP为有前途的未被充分代表的学生提供研究经验，以及旨在提高学术成就和促进STEM研究生教育的讲习班和研讨会。总共有两名研究生和几名本科生将接受环境工程、分析化学和毒理学方面的培训，这将有助于更好地为未来的研究领导者和技术人员做好准备，以应对食物-能源-水关系方面的多方面挑战。

PI Names: John SiveyProposal Number: 1703796 Many of the herbicide formulations applied to crop fields include a safener. Safeners are so-called "inert" ingredients, which are added to protect crops (but not weeds) from possible damage caused by herbicides. Safeners have application rates on par with many herbicide active ingredients; however, unlike most herbicide active ingredients, the environmental fate and effects of safeners are poorly understood. The purpose of this project is to address the extensive knowledge gaps associated with the environmental fate and ecological effects of a major class of safeners. This collaborative project unites a multidisciplinary team of experts and students from a primarily undergraduate institution (Towson University) and a doctoral-granting institution (University of Iowa) with the goal of promoting sustainable agricultural practices related to the use of safeners. This project seeks to advance our understanding of the environmental persistence and ecotoxicological risks of dichloroacetamide safeners and their transformation products. Despite being classified as "inert", safeners are biologically active and their bioactivity is anticipated to increase via selected environmental transformations (including photolysis and reductive dechlorination). Due to their extensive use, safeners likely represent an overlooked class of emerging contaminants. Using commercial safeners and their herbicidal co-formulants, this project will (1) determine their rates and mechanisms of photochemical transformation in surface waters; (2) quantify their extent of removal and/or transformation during simulated drinking water treatment; (3) establish timescales associated with their biotransformation; (4) identify products of these transformations, including how reactions alter enantiomeric signatures of chiral safeners; and (5) evaluate ecotoxicological risks of safeners and their transformation products toward non-target aquatic organisms. Commercial formulations can include enantiomerically-enriched herbicides co-formulated with racemic mixtures of safeners. As such, experiments will include individual safener enantiomers, safener racemates, and safener + herbicide binary mixtures representative of commercial formulations. As safener use is projected to increase in the future, there is urgent need to obtain reliable environmental assessment data for this chemical class. This project will provide some of the first non-industrial data necessary to assess persistence and risk associated with safeners in natural and engineered aquatic systems. Moreover, as dichloroacetamide safeners are applied extensively to corn used for food, animal feed, and biofuel production, this work confronts challenges to sustainable development at the food-energy-water nexus. As society grows increasingly reliant on agrochemical advances to feed a swelling population, this work promotes sustainable agriculture by guiding the design of environmentally-benign safener formulations. Central to this project is a research partnership between a PUI (Towson University) and an R1 (University of Iowa). A signature effort of this partnership is the participation of undergraduates in the Summer Research Opportunities Program (SROP) at the University of Iowa. SROP provides promising underrepresented students with research experience, in addition to workshops and seminars designed to enhance academic success and promote graduate education in STEM. In total, two graduate and several undergraduate students will receive training at the interface of environmental engineering, analytical chemistry, and toxicology, which will help to better prepare tomorrow's research leaders and technical workforce to confront the multi-faceted challenges at the food-energy-water nexus.