Reliable environmental exposure assessment requires fit-for-purpose tools capable of characterizing the magnitude, frequency, and duration of chemical releases under realistic use conditions. While established regulatory models, such as the European Union System for the Evaluation of Substances (EUSES), support screening-level assessment of cosmetic ingredients released down-the-drain, direct release scenarios are not addressed within current chemical safety frameworks. To address this gap, we present MERCI (Models to Evaluate the direct Release of Cosmetic Ingredients into natural waters), which is an iterative, tiered exposure assessment framework, that can be used to derive predicted environmental concentrations (PECs) from, for example, UV-filters used in sunscreen products released directly into marine and freshwater systems. The MERCI Framework integrates existing environmental fate and transport models within a transparent structure that aligns model selection with problem formulation, regulatory objectives, data availability, and resource considerations. Lower tiers apply standardized, conservative assumptions consistent with regulatory screening practices, while higher tiers incorporate increasing environmental realism, including refined emission estimates and site-specific hydrodynamics to reduce uncertainty and address complex questions. The framework is intended to be iterative, enabling users to select and refine tools as needed to support decision-making, prioritize data generation, and strengthen confidence in environmental risk assessments. As regulatory expectations and scientific understanding evolve, MERCI provides a scalable, adaptable pathway to integrate direct-release exposure scenarios, particularly those associated with the direct release of UV-filters used in sunscreen products, into chemical safety evaluations.
Deforestation and forest degradation fundamentally alter subterranean ecosystems and the biological health of soils, yet belowground recovery trajectories remain poorly integrated into restoration monitoring frameworks. Soil nematodes are powerful bioindicators, but their application in forests has largely extrapolated from agricultural paradigms without accounting for forest-specific food web structures and dynamics. This review consolidates current understanding of nematode community responses to factors contributing to forest degradation, including deforestation, soil compaction, organic matter depletion, and alterations in nutrient dynamics. It also examines the impact of various restoration initiatives on recovery trajectories. We assess the theoretical principles and practical applications of nematode-based ecological indicators, including the maturity index, enrichment index, structure index, and channel index, as diagnostic tools for evaluating forest soil health. The review examines the relationship between changes in nematode trophic group composition and fluctuations in decomposition pathways, microbial dynamics, and plant-soil feedback mechanisms. Through case studies from tropical, temperate, and boreal forests, we identify knowledge gaps regarding nematode responses to innovative restoration techniques. We provide a conceptual framework for integrating nematode community analysis into forest soil health monitoring and offer practical recommendations for utilizing nematode indicators to inform adaptive management strategies for recovery of degraded and protection of healthy forest soils.
Efforts to steer the social metabolism (i.e., how human societies interact with nature) towards sustainability are pulling assessment practice in two directions: "relative" product-to-product comparisons and "absolute" product-to-limit benchmarking, where the limit works as benchmark for the assessment. Within approaches such as Safe and Sustainable by Design, inherently threshold-based "absolute" chemical Risk Assessment is coupled to Life Cycle Assessment, which has traditionally been used as a tool for comparing alternatives. This coupling is driving the development of methodologies for comparative assessment of (eco)toxicological impact potentials (e.g., chemical footprinting). In parallel, the emergence of the Planetary Boundaries framework has renewed the interest in shifting from comparative assessments towards absolute benchmarking against global environmental limits, leading to Absolute Environmental Sustainability Assessment. This paper reviews how environmental limits are incorporated into Life Cycle Assessment through early distance to target methods (such as Ecological Scarcity, Environmental Themes, Eco-Indicator 95) to support business-driven eco-efficiency decisions and how impacts were anchored in national or regional targets and critical loads. We then discuss how the Planetary Boundaries framework reorganizes limits around Earth-system processes and how Planetary Boundaries based Life Cycle Assessment translates global boundaries into Life Cycle Assessment indicators and Planetary Boundaries based "budgets" for products and sectors. Across these developments, we show that setting and allocating thresholds reflects conflicting notions of "weak" and "strong" sustainability and is unavoidably value-laden and argue that making this "valuesphere" explicit is crucial if Planetary Boundaries based Life Cycle Assessment is to inform credible, product-level Safe and Sustainable by Design decisions on absolute sustainability.
Diffuse soil contamination represents a widespread environmental issue, resulting from multiple low-intensity and spatially dispersed sources, including atmospheric deposition, agricultural practices, traffic emissions, and legacy industrial activities. Unlike point-source pollution, diffuse contamination lacks a clear spatial origin, requiring methodologies that can integrate measured data with environmental processes. In this case concentration-based mapping alone is often insufficient to support risk-informed management decisions. This study presents a regional-scale environmental risk assessment framework for diffuse soil contamination, building on the methodological advances introduced in the companion paper (Part I) and extending them to spatially distributed pressures. The assessment is expanded to a multi-contaminant context, including both inorganic and organic compounds, and contaminant concentrations are evaluated against land-use-specific regulatory threshold values. Hazard maps are normalised according to the established criterion whereby soils are considered hazardous when concentrations exceed threshold values by one order of magnitude, enabling consistent comparison and aggregation across contaminants. Exposure is modelled through four exposure pathways (groundwater, surface water, direct contact, and air dispersion) and receptor vulnerability is further articulated for groundwater resources, surface waters, protected areas and human health. The resulting framework supports a transition from a predominantly regional human-health-oriented assessment towards a more comprehensive environmental risk assessment, producing spatially explicit prioritisation maps for individual contaminants and aggregated diffuse-contamination risk. Application to the Toulouse Metropolitan Area (France), demonstrates the ability to move beyond concentration exceedances by identifying areas of higher management priority where diffuse pressures, transport processes and receptor vulnerability converge. Implemented within a GIS-based Model Builder environment, the methodology is reproducible and transferable to other regions where soil data are available but site-specific information is limited, offering a scientifically grounded basis for supporting decision-makers in land-use planning, monitoring prioritization and early-stage risk-based management actions, in line with the new EU Soil Monitoring and Resilience Directive.
Pesticides are major stressors affecting freshwater biodiversity; however, the cumulative risks posed by multiple substances used within the same crop, across different crops, or over multi-year application cycles remain poorly understood. Here we introduce the ERAHUMED model, a modeling platform designed to assess the ecological risks of pesticide mixtures associated with rice farming at the landscape scale. The model uses the Albufera Natural Park (Valencia, Spain), one of the most important Mediterranean coastal wetlands, as a reference area. ERAHUMED integrates a hydrological module, an agricultural management module, a three-compartment (plant, water, sediment) pesticide exposure module, and a risk assessment module that employs both deterministic and probabilistic approaches for calculating pesticide risks. The model's novelty lies in its capacity to evaluate how different agrochemical management practices, including various pesticide application schemes and spatial crop patterns, along with landscape architecture, climate, and hydrological variations, influence pesticide exposure and associated risks to aquatic ecosystems. Here, we detail the model's core principles, its calibration and validation using monitoring data, and present two application case studies. These case studies demonstrate how the model can be used to compare the ecological risks posed by old and current pesticide application schemes at the landscape scale, as well as to assess the influence of extreme climatic events on pesticide exposure and risks in downstream water bodies. The model is implemented as an R package with an integrated Shiny-based graphical user interface. This implementation enables efficient landscape-scale evaluations of pesticide application schemes, agricultural management practices, and their associated ecological risks for a broad range of users, with a particular focus on researchers and environmental managers aimed at minimizing pesticide risks.
Polymer-coated fertilizer capsules are a relevant source of agricultural microplastics in paddy fields, yet controls on their mobilization during puddling remain insufficiently quantified. We investigated capsule flotation across 40 rice paddy fields in Ishikawa Prefecture, Japan. Accumulated capsule stocks in soil and water depth jointly controlled capsule mobilization to the water surface during puddling. Water depth explained a proportion of variation comparable to or greater than that explained by soil capsule concentration, indicating strong hydrological control on mobilization. The proportion of floating capsules increased with increasing water depth, and segmented regression identified a change point at approximately 8 cm under the conditions of this study, suggesting a shift in flotation behavior. Comparative analysis among fields with different management histories, together with polymer-specific indicators of soil residence time, suggested that longer soil residence is associated with lower flotation potential. Accordingly, recently accumulated capsules exhibited greater mobility than long-residence particles. These findings demonstrate that microplastic mobilization during puddling is governed by the interaction between accumulated particle stocks, hydrological conditions, and time-dependent particle properties. Consequently, agricultural microplastic discharges cannot be predicted from accumulated particle stocks alone but require explicit consideration of hydrological controls on mobilization. Water management during puddling therefore represents a practical leverage point for mitigating discharges.
Zinc (Zn) is an essential micronutrient, and its deficiency is a global issue. Zinc fertilisers are commonly used to address this, but they often have low efficiency, limiting yields and causing environmental problems. Layered double hydroxides (LDHs) are innovative nanomaterials with potential agricultural applications. To ensure their sustainability, it is crucial to understand their behaviour, fate, and toxicity in the terrestrial ecosystem. This study evaluated Zn-Al-NO3 LDH as an alternative Zn fertiliser at relevant agronomic concentrations. Zn sulfate was tested as a conventional fertiliser, and maize (Zea mays) as a test species. The assessment included plant performance, Zn use efficiency, soil functionality indicators, and Zn fate assessments. Our study showed that Zn-Al-NO3 LDH did not affect plant development and increased root Zn content, with little to no translocation to the shoots. Soil enzymatic activity increased over time, but differences in soil ecosystem multifunctionality were negligible. Low nitrate and Zn concentrations in leachates indicated reduced leaching potential. Our study demonstrates the potential of Zn-Al-NO3 LDH as an alternative to conventional Zn fertilisers at half the recommended dose. However, further research is needed to investigate its effects across different plant species and to evaluate the fate and behaviour of these nanomaterials in various soils and environmental contexts.
This study presents a comprehensive dataset of aquatic macrophyte field observations aimed at supporting higher-tier risk assessments for plant protection products (PPPs). The dataset includes species composition and abiotic conditions of edge-of-field freshwater systems such as ponds, streams, and ditches across Europe and key functional traits of their most common macrophytes. Analysis showed that the key macrophyte species are broadly distributed and are already frequently included in Species Sensitivity Distributions (SSDs) as well as in mesocosm and potted plant studies. The data collected is useful in the context of pesticide risk assessment as it provides information on which species could be focal species and information to define ecological scenarios as well as to use in ecological models. Also the data can support a reference tier that enhances ecological realism in aquatic risk assessments. A case study using the herbicide metazachlor illustrates how the dataset can inform regulatory decision-making by comparing SSD-derived endpoints based on toxicity endpoints for macrophyte species found in edge-of-field surface waters with those from traditional mesocosm studies. This approach offers an alternative to experimental systems, aligning with current regulatory goals for more representative and efficient risk assessments.
Although a growing body of research recognizes the wider values generated by brownfield remediation and restoration (BRR), there is still limited consolidated knowledge on how these values can be systematically assessed and integrated into planning and investment decisions. A semi-systematic review of scientific and grey literature was conducted to map the wider values and their economic impacts as well as economic valuation methods that have been used to monetize them while assessing potential biases, knowledge gaps and future research directions. This study contributes to the literature by providing a structured synthesis that links wider values of BRR with economic valuation methods, uncertainty considerations, and their integration into business case development. The review shows that there is a broad range of wider values linked to BRR and alternative future land uses, many of which can be monetized using various monetary valuation methods, though difficult to monetize benefits such as biodiversity and soil health improvements are underrepresented. A simplified framework is proposed to demonstrate how accounting for wider values from an economic perspective can strengthen the economic case for BRR, particularly at vacant or underutilized land with lower financial potential. Value transfer is highlighted as a promising valuation method where resources are limited, but a probabilistic approach is recommended to account for uncertainties by considering representative values for ranges (e.g., mean, mode or median values) instead of transferring highly variable point estimates. It is also recommended to carefully consider the economic valuation method for the specific project context, as some valuation estimates and methods using direct, cost-based methods like market pricing, replacement cost, etc., are highly site-specific and could be replicated using site-specific information instead of value transfer. Potential risks such as double-counting, limitations in monetization from narrow ethical viewpoints, and other biases and methodological challenges are discussed.
Maternal transfer of selenium is the critical exposure pathway for reproductive risk in birds, yet diet→egg transfer varies widely with species, diet composition, timing, and selenium speciation. We synthesized paired diet-egg datasets from wetlands and terrestrial systems together with controlled feeding studies to quantify diet→egg trophic transfer factors and evaluate their concentration dependence. Across field settings, invertebrate or fish prey frequently exceeded dietary screening levels while egg selenium yolk = 0.211factors, often ≤ 1. By contrast, laboratory selenomethionine diets produced higher, steadier trophic transfer factors, reflecting sustained, highly bioavailable exposure. A compartment analysis showed albumen responds rapidly to recent intake whereas yolk integrates over days to weeks, explaining field scatter and lab steadiness. These findings support a three‑zone conceptual model, that is deficiency, regulation band, and high exposure, in which proportional transfer is damped across the regulation band. We provide operational guidance that emphasizes aligning prey sampling to the immediate pre-laying window, considering selenium speciation (especially the selenomethionine fraction), and applying guild- and site-appropriate TTFs for forward and backward translation.
The increasing proliferation of policy-driven frameworks addressing chemical safety and sustainability has intensified the need for coherence and integration in environmental assessment and management. In the European context, Safe and Sustainable by Design (SSbD) and the EU Ecolabel represent influential but conceptually distinct instruments that may yield divergent conclusions when applied to the same product system, potentially challenging transparent and consistent decision-making. This study examines the extent to which such divergences arise from differences in assessment logic rather than from conflicting scientific evidence, using a structured case study of a representative consumer product formulation. An integrated assessment approach was applied, combining exposure-informed regulatory risk characterization with life-cycle-based toxicity prioritization. Occupational and environmental risks were quantified using established regulatory tools (Chesar® and EUSES 2.1.2), while potential human toxicity and freshwater ecotoxicity impacts were evaluated using USEtox® characterization factors. Results indicate that regulatory acceptability thresholds were achieved for nearly all modeled exposure scenarios, with a marginal exceedance of the average dermal risk characterization ratio observed for Cocamidopropyl betaine under conservative occupational exposure assumptions. In contrast, life-cycle toxicity indicators revealed marked differences in relative substance contributions to potential human and ecological impacts, reflecting intrinsic hazard and fate properties rather than exposure-driven risk. The comparative analysis demonstrates that apparent inconsistencies between SSbD and EU Ecolabel outcomes are primarily attributable to differences in decision logic, assessment scope, and the weighting of hazard-, exposure-, and life-cycle-based information. Building on these findings, a conceptual integration model is proposed to support transparent interpretation and reconciliation of assessment results across frameworks. The study contributes to ongoing discourse within the environmental assessment community by illustrating how complementary use of regulatory risk assessment and life-cycle toxicity indicators can enhance chemical risk management, reduce misalignment between policy instruments, and support more informed and consistent sustainability-oriented decisions.
Understanding the potential environmental impact of cosmetics and personal care products (PCPs) and successfully developing eco-friendly formulations requires knowledge of the aquatic toxicity of ingredients. However, for the cosmetic industry, aquatic toxicity assessments are challenged by the large number of ingredients, restrictions on animal testing and lack of chronic toxicity data. Therefore, alternative approaches are required to fill these gaps. This study aimed to evaluate the potential applicability of acute-to-chronic ratios (ACRs) and in silico tools (VEGA and OECD QSAR Toolbox) to estimate chronic aquatic toxicity values (NOECs for algae, daphnids, and fish) for a set of 41 ingredients of cosmetics and PCPs with well-defined molecular structures. Extrapolations and predictions were compared to experimental chronic toxicity data. We observed that ACR-based extrapolations were strongly correlated with experimental NOECs, particularly when using the lowest ACRs, with algae showing the strongest correlation. MoA-based ACRs did not improve the prediction of chronic values when compared to general ACRs. Extrapolated values were not consistently conservative, with both over- and underpredictions observed. The OECD QSAR Toolbox yielded more acceptable chronic toxicity predictions than VEGA, yet both exhibited weaker correlations with experimental data than the ACR-based approach. Predictive performance of the in silico models improved when analyzing the subgroup of MoA 1 substances for algae. Overall, our findings support the use of ACRs for filling chronic toxicity data gaps in screening-level assessments within environmental hazard-based tools for developing eco-friendly cosmetics and PCPs, while the freely available in silico tools require further refinement to improve performance in this context.
Due to climate change, we expect more intense hurricanes, leading to higher precipitation than previously observed. Historic storms, such as Hurricane Helene, that struck the southeastern United States (U.S.) in September 2024, deposited between 508 and 762 mm (20-30 in) of rainfall in rural, mountainous parts of Western North Carolina, resulting in catastrophic flooding. Less well known is the extent of microplastic (MP) deposition in these less developed areas. While there is insight into MP deposition due to typhoon events in Eastern Hemisphere, in our assessment, we conducted the first-ever study U.S. based assessment of MP deposition in a severely affected southeastern U.S. region at multiple locations (Iron Duff, Coweeta Hydrologic Laboratory (Coweeta), and Highlands Biological Station (HBS), months before (January to September), during (September), and weeks post-hurricane (October to November). Our findings show that Hurricane Helene contributed to elevated MP deposition at all sites (3 to 22x higher than pre-Hurricane Helene levels), where total storm MP deposition was 1,280, 2,179, and 10,243 MP/m² at Iron Duff, Coweeta, and HBS, respectively. This historic storm accounted for 4.2, 4.6, and 18.8% of the annual MP deposition at Iron Duff, Coweeta, and HBS, respectively. Using backward trajectory analysis, we found that air masses reaching our sampling locations differed during Hurricane Helene compared to pre- and post-Helene periods. Our regression model estimated that the total anomalous deposition over the area of the U.S. affected by Hurricane Helene (3,798,756.55 km²) was 3.85 × 10¹⁵ MPs. Polyamide, polystyrene, polyethylene terephthalate, polypropylene, and polyethylene were the main polymers detected before and during Hurricane Helene. Our findings underscore how extreme storms can produce short-term spikes in MP deposition above ambient levels in a region. Thus, highlight the need to prioritize funding and policy initiatives to better assess risks posed by MPs to vulnerable ecosystems.
The pervasive use of lip cosmetics results in chronic, low-dose exposure to complex mixtures of chemicals via multiple routes, yet current cosmetic safety regulations treat lip products as conventional topical applications to skin. While the EU safety assessment framework acknowledges ingestion as an exposure route for lip products, standardised lip-specific testing models do not currently exist. The US requires no mandatory pre-market safety review for cosmetic ingredients and systemic exposure consideration is confined to voluntary industry assessment (except for colour additives). In both jurisdictions, exposure estimates are based on usage data from 2005 that do not reflect current real-world usage patterns of lip cosmetics, including frequent reapplication, product layering, and marketing based on food characteristics. The unique physiology of the lips, which represent a transitional tissue between external skin and oral mucosa provides an additional exposure route: the vermilion and labial mucosa are characterized by a markedly thinner and incompletely keratinised epithelium, reduced lipid barrier components, high vascularisation, and constant moisture-collectively conferring substantially higher permeability than facial skin. Evidence from pharmacology demonstrates that oral mucosal tissues are deliberately exploited for rapid systemic drug delivery. By comparing how the oral mucosal exposure route is evaluated across cosmetic, food, and pharmaceutical regulatory regimes, this review identifies a critical regulatory gap: chemicals applied to the lips are assessed under frameworks designed for low-permeability skin, despite a biological reality more consistent with mucosal exposure. This mismatch undermines the accuracy of current risk assessments and may lead to systematic underestimation of internal dose for certain lip cosmetic ingredients including microplastics. Addressing this gap will require lip-specific exposure models, physiologically relevant in vitro systems, and updated regulatory guidance to ensure that cosmetic safety assessment accurately reflects the unique exposure profile of lip products.
Lip products occupy a regulatory blind spot. Classified as cosmetics for external application across all major jurisdictions, there are two distinct adverse outcome pathways: cutaneous absorption via lip tissue with significantly diminished barrier function, and oral ingestion documented at levels reaching half a kilogram annually for high-frequency users. We present a comparative analysis of how the United States, European Union (EU), United Kingdom (UK), Canada, China, and South Korea regulate lip products, revealing a systemic gap in how regulations address their actual exposure profile. Three critical gaps are common across all frameworks: definitional miscategorization of the exposure profile; absence of appropriate safety assessment for either ingestion or lip-tissue absorption pathways; and testing duration requirements that are absent in the majority of frameworks and, where they exist, capped at subchronic endpoints that do not reflect continuous real-world use extending far beyond 90 days. Baseline exposure data underpinning global safety assessments were collected in 2003-2005 and predate contemporary lip product categories; contemporary studies document 95th-percentile lip balm consumption at 1,270 mg/day, a 14.6-fold increase over regulatory baselines. Two regulatory paradoxes within the EU crystallize the classificatory failure: titanium dioxide, banned as a food additive over oral ingestion genotoxicity concerns, remains unrestricted in lip cosmetics with an identical ingestion pathway; and microplastics are restricted in lip products under EU chemicals regulation because of environmental release through human ingestion, while the Cosmetics Regulation assesses them under dermal parameters. This demonstrates that regulatory sophistication cannot overcome classificatory error, and that meaningful reform requires updated, population-specific exposure studies reflecting contemporary usage patterns, product categories, and consumer demographics. We recommend development of lip-appropriate assessment methodology via validated non-animal methods (within existing cosmetic regulatory frameworks, without product reclassification) and the potential extension of the food-grade ingredient safety principles accepted in industry voluntary guidance to all lip product ingredient categories.
Forests provide essential ecosystem services, particularly timber production and carbon sequestration, both of which play critical roles in climate change mitigation and sustainable forest management. However, the long-term consequences of alternative management strategies on carbon-timber trade-offs remain insufficiently understood. This study addresses this gap by analysing the combined effects of rotation length, harvest regulation strategies, and tree-size dynamics on forest carbon storage and timber production using the ETÇAP decision support system (DSS). Four management scenarios were developed by combining short and long rotation periods with area-control and volume-control harvesting policies, while explicitly accounting for tree-size-dependent carbon dynamics. Simulations were conducted for a representative forest planning unit in Türkiye over a 100-year planning horizon. Results showed that longer rotations and volume-control harvesting consistently projected the largest increase in carbon storage by promoting the development and retention of larger trees, whereas shorter rotations and area-control harvesting enhanced timber production but intensified trade-offs with carbon sequestration. While tree-size dynamics influenced the magnitude of carbon accumulation, they did not substantially alter the overall trade-off patterns among management strategies. These results indicate that management decisions affecting age structure and harvesting regimes are important determinants of long-term carbon-timber outcomes. As the analysis is based on deterministic simulations that exclude major disturbance processes such as wildfire, pest outbreaks, and climate extremes, the results need to be interpreted as scenario-based projections. Nevertheless, the study highlights the value of integrating ecosystem-based forest management with decision support systems to systematically evaluate long-term management alternatives and support climate-informed forest planning.
Dairy farms are under pressure to reduce greenhouse gas (GHG) emissions. Various carbon footprint (CF) accounting tools have been developed for calculating GHG emissions and pinpointing hotspots to support mitigation efforts. However, inconsistent methodologies often lead to variations of their results, unclear discrepancies pose barriers to credible reporting and decision making. Five open access, farm-level CF accounting tools applicable to EU livestock production were evaluated and compared for their methodologies. They were further tested through a case study of a dairy Farm in Finland for their consistency in quantifying emissions of milk production. The sensitivity of each tool was analyzed across nine mitigation scenarios to evaluate their practical utility in guiding mitigation strategies. A significant variability in total GHG emissions was observed, ranging from 415 to 913 t CO2 eq y-1, derived mainly from differences in scopes and the adoption of varying method tiers (in IPCC 2006 or IPCC 2019). While enteric fermentation and feed production remained the primary emission sources across all tools, their contributions fluctuated based on calculation methods. Solagro and the Cool Farm Tool were most responsive to mitigation strategies regarding manure management and yield improvements, while GLEAM-i and CAP'2ER (level 1) lacked the flexibility to model specific management shifts. The lack of methodological harmony causes inconsistent results, requiring careful tool selection to align with specific goals and data availability. Methodological frameworks can be harmonized with evolving standards (Product environmental footprint category rules for dairy products), meanwhile adapting scientific advances into calculations to ensure transparency and comparability.
Low- and no-calorie sweeteners (LNCS) are increasingly prevalent in food and beverages, with significant consumption growth in recent decades. This trend has led to heightened research into monitoring these non-nutritive sugar substitutes in environmental matrices, especially surface water. Many LNCS are excreted largely unchanged and are highly soluble in water, resulting in their detection in aquatic environments at concentrations ranging from ng/L to µg/L, primarily due to municipal or household wastewater discharge. While LNCS are generally considered safe for human consumption with established Acceptable Daily Intakes (ADI), their ecological risks remain an interest due to their global ubiquitous use, eventual entry into surface waters, and limited use of contemporary ecological risk assessment methodologies for these substances. We investigated five common LNCS: aspartame (ASP), cyclamate (CYC), saccharin (SAC), sucralose (SUC), and steviol glycosides (SG), an emerging natural sweetener. Utilizing data from Euromonitor International, we assessed global consumption patterns in food and beverages and generated probabilistic exposure distributions using models for the U.S. (iSTREEM®) and Europe (HydroFATE). These were compared to retrospective exposure values based on 75 curated aquatic concentration monitoring studies spanning the world. A relative exposure index was created to contextualize modeled results globally across seven regions. We integrated comprehensive aquatic ecotoxicity data from 54 additional studies with our exposure assessments for a probabilistic ecological risk evaluation. Predicted no-effect concentration (PNEC) values were established for ASP (68.8 µg/L), CYC (20-20,000 µg/L), SAC (2,000 µg/L), SG (10,000 µg/L), and SUC (9,300 µg/L). These PNECs were significantly higher than predicted environmental concentrations and observed data by one to four orders of magnitude, depending on the LNCS and exposure scenario. This suggests high margins of safety and minimal ecological risk at current usage levels. Routine updates of this risk assessment are recommended to maintain on-going aquatic safety as LNCS usage evolves.
Safe and Sustainable by Design (SSbD) is a concept introduced in the Chemical Strategy for Sustainability of the European Commission, with the ambition of guiding innovation in chemicals and materials design toward the minimization of impacts on human health and the environment. To operationalize this concept, the European Commission Joint Research Centre developed a scientific framework, which integrates safety and environmental sustainability considerations. Such a framework was then adopted by the European Commission as a recommendation, for the use of companies and research institutes working on the development of chemicals and materials. The framework brings together two different aspects: safety and environmental sustainability. Safety is addressed looking at intrinsic properties of the chemicals and assessing risks related to exposure scenarios for workers, consumers, and environment, while the environmental sustainability aspect is assessed via the application of Life Cycle Assessment (LCA) following the provisions of the Product Environmental Footprint method. The goal of this study is to test via a case study the use of LCA to assess six plasticizers, assessing the framework's applicability and proposing approaches to address challenges and research needs. Indeed, while literature on LCA of chemicals is expanding, there are still a number of open issues to be addressed. Seven pivotal challenges are presented and discussed in this study. They cover all the phases of the life cycle, from the goal and scope (benchmark definition and application to intermediate products) to Life Cycle Inventory (LCI) (availability of data, modeling of end of life, additional information and innovation perspective) and Life Cycle Impact Assessment (LCIA) (e.g., comprehensively addressing impacts related to substances of concern). The case study examined and the seven identified challenges are starting points for improving the implementation of the Safe and Sustainable by Design framework, promoting sustainable innovation in the manufacturing of chemicals and materials.
