Integrated risk assessment: from exposure through AOPs to ecosystem services

Chemical pollution exerts significant and far-reaching effects on biodiversity and the health of ecosystems. Over time, global product and technology consumption has increased the presence of human-made chemicals in the natural environment. Many of these chemicals persist in the environment and become pervasive over time, negatively affecting aquatic ecosystems globally. Aquatic ecosystems provide essential ecosystem services that benefit human society, such as the provision of food. Thus, to understand the link between chemical emissions from product and technology life cycles and their damage on ecosystem health, it is crucial to characterize damage on aquatic ecosystems associated with chemical emissions in life cycle assessment (relevant for product life cycle performance) and ecological risk assessment (relevant for water and ecosystem protection). This is pivotal in facilitating a worldwide shift towards a more sustainable application of chemicals across products and technologies and safeguarding the diversity of aquatic life.The work presented in this PhD thesis addresses the link of the life cycle of chemical emissions to damage on aquatic ecosystem health by focusing on four research objectives: (i) to develop a consistent framework to link ecotoxicological effects on aquatic organisms to damage on species diversity, functional diversity, and ecosystem services that are fully in line with the boundary conditions of LCIA, (ii) to develop a systematic ecotoxicity test data curation approach to derive a transparent and high-quality dataset of effect test data for more than 10,000 chemicals, (iii) to improve ecotoxicity effects modeling by considering differences in sensitivity of species from different taxonomic groups toward chemical exposure, and (iv) to quantitatively characterize the relationship between mixture-toxicity pressure from chemicals and observed differences in aquatic intra- and inter-species occurrence.After an introductory chapter, Chapter 2 summarizes possible methods to translate predicted ecotoxicity effects to species and functional diversity loss, culminating damage on ecosystem services damage in life cycle assessment (LCA). Section 1 of this chapter introduces a framework for linking freshwater ecotoxicity impacts to ecosystem services within LCA boundaries. Section 2 discusses approaches for linking ecotoxicity impacts to species loss, functional diversity loss, and ecosystem services damage from an LCA perspective. Section 3 explains the necessary biomonitoring methods for ES assessment, and Section 4 outlines how to link ecotoxicity effects to ecosystem service damage.Chapter 3 outlines ecotoxicity datasets for different uses, including environmental standards, life cycle assessments, and water quality evaluation. Article II highlights data curation's importance for Articles III and IV. Sections 1 and 2 discuss current data and merging challenges to improve data quality, while Section 3 outlines a curation protocol, and Section 4 presents curated data for Article III and IV analysis.Chapter 4 introduces splitting Species Sensitivity Distributions (SSDs) based on taxonomic grouping for better model fit and relevance in risk assessment unless data constraints exist. The chapter discusses the current use (Section 1) shortcomings of current SSD usage (Section 2) and introduces a conceptual framework for split SSDs (Section 3). It also covers the role of chemical use and mode of action in SSD derivation (Section 4) and highlights the importance of split SSDs in decision support (Section 5). Additionally, a case study for Life Cycle Assessment input is presented in Section 6.Chapter 5 provides a stepwise approach to link ecotoxicity impacts with species loss, making it helpful in translating model-predicted species-level effects to damage on biodiversity and ecosystem services in decision-making, like Life Cycle Impact Assessment. The chapter consists of eight sections: Section 1 outlines the fundamental steps to derive the PAF to PDF relationship from monitoring datasets, Section 2 presents chemical concentration data and msPAF(EC10) calculation, Section 3 introduces other abiotic factors that can influence aquatic biodiversity, Section 4 presents species biomonitoring data, Section 5 explores covariation between abiotic pressures including the calculated msPAF, Section 6 discusses trends in species abundance and species richness against msPAF, Section 7 present sensitivity analysis, i.e., a robustness check using a subset of data from one region (water authority) in Netherland, and Section 8 presents the derived PAF to PDF relationship.The PhD research suggests that the developed damage modeling approach fits well into the LCA framework, offering initial steps to translating ecotoxicity effects to ecosystem services damage. Furthermore, splitting species sensitivity distributions enhances the interpretation of assessment outputs, enabling a quantitative understanding of the link between a mixture toxic pressure and biodiversity loss.In conclusion, the work conducted in this PhD project contributes to research within the field of life cycle impact assessment and ecological risk assessment by advancing the understanding of the impact of chemical pollution on biodiversity and ecosystem health. It supports environmental protection, LCA, and global freshwater ecosystem management decisions

To Split or Not to Split: Characterizing Chemical Pollution Impacts in Aquatic Ecosystems with Species Sensitivity Distributions for Specific Taxonomic Groups.

Bridging applied ecology and ecotoxicology is key to protect ecosystems. These disciplines show a mismatch, especially when evaluating pressures. Contrasting to applied ecology, ecotoxicological impacts are often characterized for whole species assemblages based on Species Sensitivity Distributions (SSDs). SSDs are statistical models describing per chemical across-species sensitivity variation based on laboratory toxicity tests. To assist in the aligning of the disciplines and improve decision-support uses of SSDs, we investigate taxonomic-group-specific SSDs for algae/cyanobacteria/aquatic plants, invertebrates, and vertebrates for 180 chemicals with sufficient test data. We show that splitting improves pollution impact assessments for chemicals with a specific mode of action and, surprisingly, for narcotic chemicals. We provide a framework for splitting SSDs that can be applied to serve in environmental protection, life cycle assessment, and management of freshwater ecosystems. We illustrate that using split SSDs has potentially large implications for the decision-support of SSD-based outputs around the globe

Characterizing Freshwater Ecotoxicity of More Than 9000 Chemicals by Combining Different Levels of Available Measured Test Data with In Silico Predictions

Ecotoxicological impacts of chemicals released into the environment are characterized by combining fate, exposure, and effects. For characterizing effects, species sensitivity distributions (SSDs) estimate toxic pressures of chemicals as the potentially affected fraction of species. Life cycle assessment (LCA) uses SSDs to identify products with lowest ecotoxicological impacts. To reflect ambient concentrations, the Global Life Cycle Impact Assessment Method (GLAM) ecotoxicity task force recently recommended deriving SSDs for LCA based on chronic EC10s (10% effect concentration, for a life-history trait) and using the 20th percentile of an EC10-based SSD as a working point. However, because we lacked measured effect concentrations, impacts of only few chemicals were assessed, underlining data limitations for decision support. The aims of this paper were therefore to derive and validate freshwater SSDs by combining measured effect concentrations with in silico methods. Freshwater effect factors (EFs) and uncertainty estimates for use in GLAM-consistent life cycle impact assessment were then derived by combining three elements: (1) using intraspecies extrapolating effect data to estimate EC10s, (2) using interspecies quantitative structure-activity relationships, or (3) assuming a constant slope of 0.7 to derive SSDs. Species sensitivity distributions, associated EFs, and EF confidence intervals for 9862 chemicals, including data-poor ones, were estimated based on these elements. Intraspecies extrapolations and the fixed slope approach were most often applied. The resulting EFs were consistent with EFs derived from SSD-EC50 models, implying a similar chemical ecotoxicity rank order and method robustness. Our approach is an important step toward considering the potential ecotoxic impacts of chemicals currently neglected in assessment frameworks due to limited test data

To Split or Not to Split: Characterizing Chemical Pollution Impacts in Aquatic Ecosystems with Species Sensitivity Distributions for Specific Taxonomic Groups

Bridging applied ecology and ecotoxicology is key to protect ecosystems. These disciplines show a mismatch, especially when evaluating pressures. Contrasting to applied ecology, ecotoxicological impacts are often characterized for whole species assemblages based on Species Sensitivity Distributions (SSDs). SSDs are statistical models describing per chemical across-species sensitivity variation based on laboratory toxicity tests. To assist in the aligning of the disciplines and improve decision-support uses of SSDs, we investigate taxonomic-group-specific SSDs for algae/cyanobacteria/aquatic plants, invertebrates, and vertebrates for 180 chemicals with sufficient test data. We show that splitting improves pollution impact assessments for chemicals with a specific mode of action and, surprisingly, for narcotic chemicals. We provide a framework for splitting SSDs that can be applied to serve in environmental protection, life cycle assessment, and management of freshwater ecosystems. We illustrate that using split SSDs has potentially large implications for the decision-support of SSD-based outputs around the globe

To Split or Not to Split: Characterizing Chemical Pollution Impacts in Aquatic Ecosystems with Species Sensitivity Distributions for Specific Taxonomic Groups

Bridging applied ecology and ecotoxicology is key to protect ecosystems. These disciplines show a mismatch, especially when evaluating pressures. Contrasting to applied ecology, ecotoxicological impacts are often characterized for whole species assemblages based on Species Sensitivity Distributions (SSDs). SSDs are statistical models describing per chemical across-species sensitivity variation based on laboratory toxicity tests. To assist in the aligning of the disciplines and improve decision-support uses of SSDs, we investigate taxonomic-group-specific SSDs for algae/cyanobacteria/aquatic plants, invertebrates, and vertebrates for 180 chemicals with sufficient test data. We show that splitting improves pollution impact assessments for chemicals with a specific mode of action and, surprisingly, for narcotic chemicals. We provide a framework for splitting SSDs that can be applied to serve in environmental protection, life cycle assessment, and management of freshwater ecosystems. We illustrate that using split SSDs has potentially large implications for the decision-support of SSD-based outputs around the globe

Assessing life cycle impacts from toxic substance emissions in major crop production systems in Thailand

Toxicity-related impacts are often omitted or poorly represented in environmental performance assessments of agricultural production systems. Moreover, existing studies usually focus on selected aspects, such as pesticides, and rely on generic data and models, hampering decision support that considers trade-offs and regional characteristics. The present study comprehensively assesses life cycle toxicity impacts of major crop production systems in Thailand, considering all relevant supply chain operations, farm-level field operations, and downstream crop residue burning. Impact characterization factors for farm-level and downstream processes have been specifically parameterized for Thai conditions, and all impacts were translated into damage costs for different scenarios based on Thailand's action plans for agricultural production, air pollution control and energy consumption, to facilitate targeted decision support at the national level. Toxicity-related impacts vary considerably across Thai crop production, ranging from a few hours (cassava, sugarcane, palm oil) to 1.5 months (rice) of average individual human lifetime loss, and from 15 (sugarcane) to 147 (rice) million species fraction lost over time and water volume. Combined, these crop systems caused damage equivalent to >3.5 trillion Thai Baht in 2019, dominated by pesticide and manure/fertilizer-related farm-level emissions for human health and by fertilizer and fuel-related supply chain operations for ecosystem damage. The scenarios could substantially reduce toxicity-related impacts on humans and ecosystems substantially across almost all considered crop production systems, mainly through adopting integrated approaches, including optimal use of crop residues and swine manure, and reducing pesticide use and diesel consumption for field operations. Our results demonstrate that including all life cycle operations and regionalized impact factors is crucial to respectively identify major trade-offs across production scenarios and account for country-specific characteristics. The proposed approach is suitable to inform national strategies supporting more sustainable crop production, and can be adapted to consider other production systems and regions