Periodic Reporting for period 1 - ISOTOPEST (ISOtope TOols for assessing PESticide faTe in the environment)
Reporting period: 2019-11-01 to 2021-10-31
Assessing the source and fate of pesticides in the environment is vital for improving water management policies and remediation actions. Although compound specific isotope analysis (CSIA) has proved to be a valuable complementary tool to track and quantify pollutant degradation and to identify contamination sources, its application to pesticides is still emerging. There are some analytical challenges that restrict the possibilities to exploit the full potential of CSIA in pesticides for environmental applications. To give a sound base on CSIA application in real-case studies, it is also crucial to understand the pesticide transformation processes and their associate isotope fractionations.
In this context, the main objective of ISOTOPEST is to tackle analytical and mechanistic issues that currently limit the application of CSIA for assessing the environmental fate of pesticides, and to provide tools for push forward the frontiers for the implementation of CSIA for environmental studies by industry and regulators. The following challenges are addressed in this project:
-Measurement of isotope ratios for low concentrations of organic compounds in environmental matrices remains one of the major challenges. Isotope-effect-free methods are required for allowing isotope analysis at low concentrations. WP1 of this project aims to overcome these barriers by optimizing extraction and analytical methods for measuring isotope ratios in two pesticides of high environmental concern: the triazine herbicide atrazine and the organochlorine insecticide methoxychlor.
-The database of isotope fractionations associated to different transformation reactions for each pesticide is extremely incomplete. Understanding the transformation processes and their associate isotope fractionations is crucial to give a sound base on CSIA application in real case studies. WP2 of this project aims to increase this database by performing laboratory experiments for knowledge advancement on pathways, mechanisms, and isotope effects of degradation of atrazine and methoxychlor.
-To take the next step and bring CSIA of pesticides to the field, the WP3 of this project is focused on application of CSIA in two contaminated sites for assessing the fate of the target pesticides: a hypersaline lake-aquifer system affected by agricultural activities and contaminated with atrazine, and a fractured aquifer contaminated with methoxychlor as a result of the activities of a former chemical plant. This will provide a further demonstration of the options of CSIA in the evaluation of strategies for natural or induced attenuation, and to trace the sources, sinks and fate of pesticides in the environment.
With these aims, preconcentration and analytical methods for the target pesticides were developed and fully validated. The use of these techniques makes the results and outcomes of the ISOTOPEST project very original and innovative. Furthermore, the project increased the database of isotope fractionations associated to different pesticide transformation processes, which could be relevant under natural conditions or for future remediation approaches. Finally, ISOTOPEST brought demonstration of CSIA in field studies. Multiple lines of evidence, including CSIA, were used for assessing natural attenuation of the target pesticides in the two study sites. These outcomes will give a sound base on CSIA application in real case studies. ISOTOPEST will thus contribute to the competitiveness of Europe in environmental monitoring, risk assessment and contamination mitigating concepts of pesticides.
In this context, the main objective of ISOTOPEST is to tackle analytical and mechanistic issues that currently limit the application of CSIA for assessing the environmental fate of pesticides, and to provide tools for push forward the frontiers for the implementation of CSIA for environmental studies by industry and regulators. The following challenges are addressed in this project:
-Measurement of isotope ratios for low concentrations of organic compounds in environmental matrices remains one of the major challenges. Isotope-effect-free methods are required for allowing isotope analysis at low concentrations. WP1 of this project aims to overcome these barriers by optimizing extraction and analytical methods for measuring isotope ratios in two pesticides of high environmental concern: the triazine herbicide atrazine and the organochlorine insecticide methoxychlor.
-The database of isotope fractionations associated to different transformation reactions for each pesticide is extremely incomplete. Understanding the transformation processes and their associate isotope fractionations is crucial to give a sound base on CSIA application in real case studies. WP2 of this project aims to increase this database by performing laboratory experiments for knowledge advancement on pathways, mechanisms, and isotope effects of degradation of atrazine and methoxychlor.
-To take the next step and bring CSIA of pesticides to the field, the WP3 of this project is focused on application of CSIA in two contaminated sites for assessing the fate of the target pesticides: a hypersaline lake-aquifer system affected by agricultural activities and contaminated with atrazine, and a fractured aquifer contaminated with methoxychlor as a result of the activities of a former chemical plant. This will provide a further demonstration of the options of CSIA in the evaluation of strategies for natural or induced attenuation, and to trace the sources, sinks and fate of pesticides in the environment.
With these aims, preconcentration and analytical methods for the target pesticides were developed and fully validated. The use of these techniques makes the results and outcomes of the ISOTOPEST project very original and innovative. Furthermore, the project increased the database of isotope fractionations associated to different pesticide transformation processes, which could be relevant under natural conditions or for future remediation approaches. Finally, ISOTOPEST brought demonstration of CSIA in field studies. Multiple lines of evidence, including CSIA, were used for assessing natural attenuation of the target pesticides in the two study sites. These outcomes will give a sound base on CSIA application in real case studies. ISOTOPEST will thus contribute to the competitiveness of Europe in environmental monitoring, risk assessment and contamination mitigating concepts of pesticides.
Several tasks were performed within ISOTOPEST to accomplish the aforementioned objectives. Extraction, preconcentration and analytical target methodologies were developed for concentration analysis and multi-element CSIA of the target pesticides at environmentally relevant concentrations in different environmental compartments, including saline and fresh water, groundwater and sediments/slurries. Developed methods allowed accurate and precise CSIA of atrazine, desethylatrazine, methoxychlor and methoxychlor olefin in environmental samples and opened new applications for CSIA.
Laboratory experiments were carried out for providing reference isotope fractionation values for degradation mechanisms occurring under different hydrogeochemical conditions: biodegradation under well-defined conditions and model systems for specific degradation reactions (e.g. hydrolysis, reductive dechlorination, etc.). This new knowledge about isotope fractionation during degradation of atrazine and methoxychlor under different transformation conditions will be the basis of revelation of degradation mechanisms and pathways and for quantifying in situ (bio)degradation and/or remediation efficiencies.
Comprehensive field monitoring studies were performed, collecting both surface/groundwater and soil/sediments and applying the methods developed in this project for assessing atrazine fate in a hypersaline lake-aquifer system affected by significant agricultural activities, and potential methoxychlor natural attenuation in a complex fractured aquifer contaminated with pesticides and chlorinated volatile organic compounds. The multi-method assessment, including CSIA of pesticides and microbiological tools, allowed determining the natural attenuation capacity of the subsurface and identifying the main pesticide degradation pathways.
Project results were disseminated through diverse means: research seminars to academic staff, postgraduates and postdoctoral researchers; publication of several open-access journal articles (under preparation); online technical workshops to environmental professionals, which were also open to the general public; online outreach events, such as the European Researchers’ Night; website of the project; social media platforms including LinkedIn and Twitter; among others. These events were also used for knowledge transfer and promotion of the new services and analytical capabilities of the host.
Laboratory experiments were carried out for providing reference isotope fractionation values for degradation mechanisms occurring under different hydrogeochemical conditions: biodegradation under well-defined conditions and model systems for specific degradation reactions (e.g. hydrolysis, reductive dechlorination, etc.). This new knowledge about isotope fractionation during degradation of atrazine and methoxychlor under different transformation conditions will be the basis of revelation of degradation mechanisms and pathways and for quantifying in situ (bio)degradation and/or remediation efficiencies.
Comprehensive field monitoring studies were performed, collecting both surface/groundwater and soil/sediments and applying the methods developed in this project for assessing atrazine fate in a hypersaline lake-aquifer system affected by significant agricultural activities, and potential methoxychlor natural attenuation in a complex fractured aquifer contaminated with pesticides and chlorinated volatile organic compounds. The multi-method assessment, including CSIA of pesticides and microbiological tools, allowed determining the natural attenuation capacity of the subsurface and identifying the main pesticide degradation pathways.
Project results were disseminated through diverse means: research seminars to academic staff, postgraduates and postdoctoral researchers; publication of several open-access journal articles (under preparation); online technical workshops to environmental professionals, which were also open to the general public; online outreach events, such as the European Researchers’ Night; website of the project; social media platforms including LinkedIn and Twitter; among others. These events were also used for knowledge transfer and promotion of the new services and analytical capabilities of the host.
The results of this project represent significant advances to the state of the art of the application of CSIA to environmentally relevant emerging contaminants. In particular, ISOTOPEST have provided a demonstration of the options of CSIA in the evaluation of strategies for natural or induced attenuation, and to trace the environmental fate of pesticides. The final aim is to enable the implementation of the gained knowledge and the developed techniques for a sustainable water and agriculture management and to boost CSIA application to other organic micropollutants for which isotope analysis is still emerging.
The research conducted within ISOTOPEST had great social relevance, since the project outcomes will contribute to improve water quality. The project provided tools and solutions for protecting water environments, enhancing water quality and improving its management, in line with the EU Zero Pollution Action Plan. Water quality is one of the priority issues of the environmental policy agenda due to the increasing demand for safe and clean water. ISOTOPEST outcomes could be used by the administration for addressing point and diffuse pollution and for a more sustainable management of water resources. In particular, the use of multi-isotopic tools will improve the decision making in contaminated sites, with the consequent cost and time savings. This could have a huge impact on the competitiveness of the European industry.
The research conducted within ISOTOPEST had great social relevance, since the project outcomes will contribute to improve water quality. The project provided tools and solutions for protecting water environments, enhancing water quality and improving its management, in line with the EU Zero Pollution Action Plan. Water quality is one of the priority issues of the environmental policy agenda due to the increasing demand for safe and clean water. ISOTOPEST outcomes could be used by the administration for addressing point and diffuse pollution and for a more sustainable management of water resources. In particular, the use of multi-isotopic tools will improve the decision making in contaminated sites, with the consequent cost and time savings. This could have a huge impact on the competitiveness of the European industry.