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

PI名称：John Sivey提案编号：1703796许多用于农田的除草剂制剂都含有安全剂。安全剂是所谓的“惰性”成分，添加这些成分是为了保护作物（但不是杂草）免受除草剂可能造成的损害。安全剂的施用率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知之甚少。该项目的目的是解决与一个主要类别的安全剂的环境归宿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院校（陶森大学）和一个博士授予机构（爱荷华州大学），目标是促进与使用安全剂有关的可持续农业实践。本项目旨在提高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认识。尽管被归类为“惰性”，但安全剂具有生物活性，预计其生物活性会通过选定的环境转化（包括光解和还原脱氯）而增加。由于其广泛的使用，安全剂可能是一类被忽视的新出现的污染物。该项目将利用商业安全剂及其除草助剂，（1）确定其在地表沃茨中的光化学转化速率和机制;（2）量化其在模拟饮用水处理过程中的去除和/或转化程度;（3）确定其生物转化的时间表;（4）鉴定这些转化的产物，包括反应如何改变手性安全剂的对映体特征;评价安全剂及其转化产物对非靶水生生物的生态毒理风险。商业制剂可以包括与安全剂的外消旋混合物共同配制的对映体富集的除草剂。因此，实验将包括代表商业制剂的单独的安全剂对映异构体、安全剂外消旋体和安全剂+除草剂二元混合物。由于预计今后安全剂的使用将增加，因此迫切需要获得这类化学品的可靠环境评估数据。该项目将提供评估与安全剂在自然和工程水生系统中的持久性和风险有关的第一批必要的非工业数据。此外，由于二氯乙酰胺安全剂被广泛应用于用于食品、动物饲料和生物燃料生产的玉米，这项工作在粮食-能源-水关系方面面临着可持续发展的挑战。随着社会越来越依赖农业化学进步来养活不断膨胀的人口，这项工作通过指导环境友好型安全剂配方的设计来促进可持续农业。该项目的核心是PUI（陶森大学）和R1（爱荷华州大学）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州大学的夏季研究机会计划（SROP）。SROP为有前途的代表性不足的学生提供研究经验，除了旨在提高学术成功和促进STEM研究生教育的研讨会和研讨会。 总的来说，两名研究生和几名本科生将接受环境工程，分析化学和毒理学接口的培训，这将有助于更好地准备明天的研究领导者和技术人员，以应对食品-能源-水关系的多方面挑战。

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.