February 12, 2024 by Graham Merrington

CREED blog

When undertaking an environmental risk assessment for a chemical there are commonly two key inputs; the first is related to the how hazardous the chemical is, most often determined through the use of ecotoxicity test data and the second modelled or measured concentrations of the chemical in the environmental matrices of interest (soil, water, sediment, biota, etc.). Most regulatory jurisdictions with responsibilities for deriving hazard metrics for use in environmental risk assessment have clear guidance to assess the reliability and relevance of ecotoxicity test data. This guidance reduces the need for ‘expert judgement’ and so delivers consistency, accountability, and repeatability of outcomes. The guidance also means that researchers and practitioners undertaking ecotoxicity testing can ensure their data are useable for risk assessment purposes (ever more important as concerns righty grow around the need to reduce wasteful and frivolous animal testing). Familiar schemes and approaches, such as CRED (Criteria for Reporting and Evaluating Ecotoxicity Data) and Klimisch, are widely used.

Unfortunately, no comprehensive guide exists to assess the reliability and relevance of the second input to the environmental risk assessment of a chemical, the modelled or monitored concentration data in the environment, also known as exposure data. In 2021 a SETAC (Society of Environmental Toxicology and Chemistry) Technical Workshop was held in Copenhagen, with 35 experts from over 20 countries (including Adam, Iain, and Graham from wca), charged with the aim and for the first time of developing practical, implementable Criteria for Reporting and Evaluating Exposure Datasets. The sibling of CRED, CREED (Criteria for Reporting and Evaluating Exposure Datasets) is now about to published online in Integrated Environmental Assessment and Management. The four-paper series (An introduction to Criteria for Reporting and Evaluating Exposure Data (CREED); Evaluating the reliability of environmental concentration data to characterize exposure in environmental risk assessments; Assessing the relevance of environmental exposure data sets; Implementation of the CREED approach for environmental assessments), detail the specifics of the approach, that can be considered as best practice including the need to clearly define the purpose of the assessment, gateway criteria, detailed reliability and relevance criteria, a transparent and intuitive scoring system, template, and report card.

Like CRED, CREED aims to deliver a consistent, transparent, and useable approach for exposure data users, generators, and database owners, facilitating best practice in our assessment of potential chemical risks (and best use of finite resources in generating data). The reliability and relevance requirements for an exposure dataset used to assess Quality Standard compliance at a site, are inevitably different from state of the environment reporting or data used for chemical authorisation or registration. The CREED approach demonstrates with examples that, perhaps not surprisingly, not all exposure data are fit for all assessment purposes (as discussed here).

SETAC are holding a webinar on the general aspects of CREED 14th March 2024, with a second  in mid April on the practical application of CREED. There is a session at SETAC Europe in Seville in May dedicated to CREED also a ‘Drop-in’ meeting regarding dealing with data challenges and CREED. Please do read the papers, The SETAC Globe Article and use CREED – feedback is always helpful(!). What works, what doesn’t? Hopefully, we’ll see you at one of the webinars or at SETAC EU!