Announcing the New Persistence Science Interest Group

Christopher B. Hughes, Aina C. Wennberg, Kostas Andreou, Glauco Battagliarin, Pippa Curtis-Jackson, Dieter Hennecke, Delina Lyon, Jose-Julio Ortega-Calvo, Amelie Ott, Zhiyi Rong, Gabriel Sigmund

As the inaugural steering committee, it is our pleasure to announce the launch of a new SETAC Interest Group – the Persistence Science Interest Group (PSIG). The degradation of chemicals in the environment has important implications for exposure, risk and legacy contamination. Degradation may occur through various processes, both biological and abiotic; to varying extents (primary transformation through to complete mineralization); and throughout the environment under a multitude of conditions. The tendency for chemicals and their transformation products to remain intact in the environment and resist degradation processes is termed as persistence.

At present, persistence is a “hot topic” at SETAC, with significant interest as there are both rapid research and policy developments in the area. There has been a sustained organic growth in related sessions, abstracts and audience sizes at SETAC conferences. However, until now, there has been no general forum for discussion or point at which experts can connect, share and find out about the latest research on persistence. This stands in contrast to other distinct but related topic areas, such as bioaccumulation, exposure assessment and environmental monitoring. As a result, an opportunity for focused attention and development of the topic was being missed. The PSIG will therefore serve to cultivate and sustain this interest by supporting and promoting activities, reporting on developments, and providing a clear point of contact for SETAC members with an interest in the topic.

The interest in persistence at SETAC has steadily been increasing in recent years, in line with growing public, policy and research interest in the topic. This interest has been catalyzed by notable issues of widespread alarm, such as concerns surrounding the environmental and health risks of highly persistent (micro)plastic particles and per- and polyfluoroalkyl substances (PFAS). There have been dedicated sessions related to (bio)degradation and/or persistence in many of the recent SETAC Europe annual meetings. The upcoming SETAC Europe 34th Annual Meeting in Seville, Spain, promises to continue this trend, with sessions on biodegradation and persistence, PMT/vPvM substances, polymer degradation and transformation products. Furthermore, numerous workshops related to persistence have been organized in recent years.

Purpose and Scope of the PSIG

The purpose of the PSIG is to provide a venue for all stakeholders to discuss and foster advancements in the development of understanding of degradation and persistence of chemicals. This specifically concerns any degradation processes that a chemical may undergo while in the environment. All aspects of degradation are considered relevant, including rates, pathways, controlling processes and factors, and transformation products.

For completeness, chemical degradation processes occurring in man-made infrastructure designed to promote the attenuation of waste streams through degradation, such as sewerage and wastewater treatment infrastructure and industrial composting, is considered included in the remit of PSIG. Persistence science commonly is centered around environmental fate in end-of-life stages of a chemical. However, scenarios are envisaged where other lifecycle stages may be relevant (e.g., with pesticides, building materials, outdoor clothing), and are likely to become more prevalent as society moves toward a circular economy. The PSIG will consider the degradation of all organic chemicals within its remit, irrespective of the nature, source, application or sector.

A further objective is to support the development of tools and approaches for assessing degradation and persistence. Degradation is commonly assessed prospectively using a range of standardized laboratory tests reflective of a narrow selection of environments. These tests are designed to address a range of degradation processes, under various conditions and levels of complexity. However, there are shortcomings with standardized testing to address particular hypotheses, information needs, environmental conditions and substance types, and there is a need for continuous refinement of existing methods, as well as development and adoption of novel approaches. Further, the validation of these methods to adequately model degradation of chemicals in the real environment remains a constant challenge. There is, thus, a desire to improve methods and make better use of information from the field to assess degradation. Computational methods for predicting degradation are also essential tools whose development can be fostered within this group. In addition to data from degradation experiments, other information such as from environmental monitoring and modeling may be key to a robust understanding of persistence. Further, persistence assessment requires a weight-of-evidence approach to combine relevant information to reach scientifically acceptable conclusions. This IG will support the ongoing development and improvement of these approaches.

Specific Topics of Interest of PSIG

• Biological and abiotic degradation processes affecting chemicals, occurring under different environmental conditions. Factors and processes controlling the occurrence and rates of these processes, including bioavailability.
• Degradation pathways and transformation products
• Methods for assessing (bio)degradation of chemicals, including new and improved experimental testing methods and in silico methods, as well as high-throughput methods
• Regulatory (bio)degradation and persistence assessment practices, including weight-of-evidence
• Understanding and assessing microbial community and enzyme composition and dynamics and its implications for biodegradation of chemicals
• Novel approaches addressing the issue of lab-to-field extrapolation and improving understanding of degradation processes in the real environment. These may incorporate monitoring and/or modeling, or other techniques.
• Sustainable by design chemistry and understanding chemical properties relevant for non-persistence

The steering committee welcomes all interested SETAC members to join the PSIG Interest Group and contribute to furthering the understanding of all aspects of chemical degradation and environmental persistence. For those attending the SETAC Europe 34th Annual Meeting in Seville, please join us for our first membership meeting from 14:30–15:30 on Tuesday, 7 May, in the Press Room.

This topic is hugely complex, requiring diverse and multidisciplinary expertise and techniques to explore it, and there remains a wealth of unanswered scientific questions to investigate. We look forward to the many interesting discussions, collaborations with other IGs, and new connections and friendships that this activity promises to bring.

Author's contact: [email protected]