- Development of practicable data-driven approaches to assess unintentional mixtures, addressing data constraints.
- Creation of a curated database on chemical modes of action and employing mechanistic information from in vitro bioanalytical NAMs for improved mixture assessment.
- Provision of a guidance document for developing and assessing context-related reference mixtures using monitoring and NAM data, including a reference mixture for European wastewater treatment plant effluents.
Key messages
- Mode of action data and curated effect concentrations for more than 3300 environmentally relevant chemicals are provided as FAIR data set for mixture risk assessments.
- 80 chemicals are ubiquitously released by European waste-water treatment plants and provide a cross-regulation mixture that should be regulated as background baseline pollution in European riverine systems.
- Austrian groundwater monitoring data were clustered to identify potential mixtures, identified mixture risk drivers were also assessed in drinking water to assess a potential health risk for humans.
Overview
This project focuses on improving how we assess and manage the risks of chemical mixtures ↗ to better protect human health and the environment. Currently, most regulations evaluate chemicals one by one, but people and nature are exposed to multiple chemicals at the same time. For mixture risk assessment, information on co-exposures and potential effects of all individual mixture components is required. This project aims to provide data and approaches to derive such data on a European scale, to deal with respective datasets, and to extract relevant information that can be applied and standardised for chemical mixture risk assessment.
A key part of the project is the collection and analyses of chemical monitoring data and the identification of mixture risk drivers, their heterogeneity, the derivation of potential reference mixtures for regulation, and the provision of data sets suitable for large scale mixture risk assessments. Next to monitoring data and co-exposure information, effect data for chemicals generated with New Approach Methodologies (NAMs ↗) as well as mode-of-action information will be included and considered within mixture risk assessment approaches to accompany and support ongoing activities on chemical grouping for mixture risk assessments.
By testing and refining these approaches, the project aims to improve how chemical risks are evaluated and managed.
Key research questions are:
- How can representative reference mixtures be developed and applied?
- How can mixture risk drivers be identified and how many of them do we need to deal with?
- Where are the largest data gaps and challenges for comprehensive mixture risk assessment?
- Which chemicals should be considered jointly also cross regulation due to unintended co-occurence?
- How can NAM data provide a comprehensive picture of chemical exposure for risk assessment?
Achievements & Results
- Data will help define common assessment groups being developed by EFSA and facilitate the aggregation of single substances and combined mixture exposures across various regulations and regulatory sectors.
- Identified priority mixtures and mixture risk drivers, containing chemicals recently assessed or regulated by different authorities, supporting tiered mixture assessment strategies under directives like the European Water Framework Directive ↗ and the European Drinking Water Directive ↗.
Related Publications
Chemicals in the aquatic environment can be harmful to organisms and ecosystems. Knowledge on effect concentrations as well as on mechanisms and modes of interaction with biological molecules and signaling pathways is necessary to perform chemical risk assessment and identify toxic compounds.
To this end, we developed criteria and a pipeline for harvesting and summarizing effect concentrations from the US ECOTOX database for the three aquatic species groups algae, crustaceans, and fish and researched the modes of action of more than 3,300 environmentally relevant chemicals in literature and databases.
We provide a curated dataset ready to be used for risk assessment based on monitoring data and the first comprehensive collection and categorization of modes of action of environmental chemicals.
Authorities, regulators, and scientists can use this data for the grouping of chemicals, the establishment of meaningful assessment groups, and the development of in vitro and in silico approaches for chemical testing and assessment.
Authorities, regulators, and scientists can use this data for the grouping of chemicals, the establishment of meaningful assessment groups, and the development of in vitro and in silico approaches for chemical testing and assessment.
Chemicals in the aquatic environment can be harmful to organisms and ecosystems. Knowledge on efect concentrations as well as on mechanisms and modes of interaction with biological molecules and signaling pathways is necessary to perform chemical risk assessment and identify toxic compounds. To this end, we developed criteria and a pipeline for harvesting and summarizing efect concentrations from the US ECOTOX database for the three aquatic species groups algae, crustaceans, and fsh and researched the modes of action of more than 3,300 environmentally relevant chemicals in literature and databases. We provide a curated dataset ready to be used for risk assessment based on monitoring data and the frst comprehensive collection and categorization of modes of action of environmental chemicals. Authorities, regulators, and scientists can use this data for the grouping of chemicals, the establishment of meaningful assessment groups, and the development of in vitro and in silico approaches for chemical testing and assessment.
Design of reference mixture of organic micropollutants from European waste water treatment plan (WWTP) effluents was provided.
Reference mixture (EWERBmix) represents baseline risk for European WWTP effluents.
EWERBmix is a proxy for monitoring and regulation purposes addressing mixture risks.
Aquatic environments are polluted with a multitude of organic micropollutants, which challenges risk assessment
due the complexity and diversity of pollutant mixtures. The recognition that certain source-specific background
pollution occurs ubiquitously in the aquatic environment might be one way forward to approach mixture risk
assessment. To investigate this hypothesis, we prepared one typical and representative WWTP effluent mixture of
organic micropollutants (EWERBmix) comprised of 81 compounds selected according to their high frequency of
occurrence and toxic potential. Toxicological relevant effects of this reference mixture were measured in eight
organism- and cell-based bioassays and compared with predicted mixture effects, which were calculated based
on effect data of single chemicals retrieved from literature or different databases, and via quantitative structure-
activity relationships (QSARs). The results show that the EWERBmix supports the identification of substances
which should be considered in future monitoring efforts. It provides measures to estimate wastewater back-
ground concentrations in rivers under consideration of respective dilution factors, and to assess the extent of
mixture risks to be expected from European WWTP effluents. The EWERBmix presents a reasonable proxy for
regulatory authorities to develop and implement assessment approaches and regulatory measures to address
mixture risks. The highlighted data gaps should be considered for prioritization of effect testing of most prevalent
and relevant individual organic micropollutants of WWTP effluent background pollution. The here provided
approach and EWERBmix are available for authorities and scientists for further investigations. The approach
presented can furthermore serve as a roadmap guiding the development of archetypic background mixtures for
other sources, geographical settings and chemical compounds, e.g. inorganic pollutants.