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

PI名称：John SiveyProposal编号：1703796许多应用于农作物田地的除草剂配方中都含有安全剂。安全剂是所谓的“惰性”成分，添加这些成分是为了保护农作物(但不是杂草)免受除草剂可能造成的损害。安全剂的使用率与许多除草剂活性成分不相上下；然而，与大多数除草剂活性成分不同，安全剂对环境的命运和影响知之甚少。该项目的目的是解决与一大类安全人员的环境命运和生态影响有关的广泛知识差距。这一合作项目联合了一个多学科的专家和学生团队，他们来自一个主要是本科生的机构(Towson大学)和一个授予博士学位的机构(爱荷华州大学)，目的是促进与使用安全器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品的环境持久性和生态毒性风险的理解。尽管被归类为“惰性”，但安全剂具有生物活性，预计通过选定的环境变化(包括光解和还原脱氯)，其生物活性将增加。由于它们的广泛使用，安全器可能代表着一类被忽视的新出现的污染物。利用商业安全剂及其除草剂共配方，该项目将(1)确定它们在地表水中的光化学转化速率和机理；(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)确定这些转化的产品，包括反应如何改变手性安全剂的对映体特征；以及(5)评估安全剂及其转化产品对非目标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富含对映体的除草剂。因此，实验将包括单独的安全剂对映体、安全剂外消旋体和代表商业配方的安全除草剂二元混合物。由于预计未来将增加更安全的使用，迫切需要为这一化学类别获得可靠的环境评估数据。该项目将提供一些第一批必要的非工业数据，以评估与天然和工程水生系统中的安全器相关的持久性和风险。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，这项工作在食品-能源-水关系上面临可持续发展的挑战。随着社会越来越依赖农用化学品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剂配方的设计来促进可持续农业。该项目的核心是PUI(Towson University)和R1(Iowa University Of Iowa)之间的研究合作。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暑期研究机会计划(SROP)。除了旨在提高学术成就和促进STEM研究生教育的研讨会和研讨会外，SROP还为有前途的代表不足的学生提供研究经验。总体而言，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队伍做好准备，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.