Filling Ecotoxicity Data Gaps for Plasticizers via an Integrated Framework: Toxicity Prediction, Prioritization, and Hazardous Concentration Derivation.

Terrestrial Ecotoxicity of Plastics: Effect Factors for Life Cycle Impact Assessment

Soils act as major plastic pollution sinks, with potential implications for terrestrial ecosystem services. In life cycle assessment (LCA), such impacts are quantified using characterization factors that describe the fate, exposure, and effects of emitted substances. In this study, we develop terrestrial ecotoxicity exposure-and-effect factors (XEFs) for plastics in soil for use in LCA. We compiled 680 effect concentrations (ECs) from published ecotoxicity studies involving plants and invertebrates and converted them to EC10eq values. Following the USEtox framework, species-specific average EC10eq values were used to construct log–normal fitted species sensitivity distribution curves, from which XEFs were derived. The resulting XEF for plastics in soil equals 0.128 [0.07; 0.30] PAF·m3·kg–1. Specific XEFs for nanoplastics ≤1 μm and plastics >1 μm were calculated at 0.921 [0.11; 13.10] and 0.126 [0.07; 0.29] PAF·m3·kg–1, respectively. Specific XEFs for natural and agricultural soil were estimated at 0.159 [0.08; 0.40] and 0.236 [0.09; 0.77] PAF·m3·kg–1, respectively. The derived XEFs are lower than aquatic and sediment XEFs by 4 and 2 orders of magnitude, respectively. Consequently, direct read-across between compartments is not justified. Overall, the proposed XEFs are compatible with the USEtox methodology and enable improved inclusion of plastic-related terrestrial ecotoxicity impacts in LCA.

An integrated framework for ecological risk assessment of microplastics in aquatic sediments.

Microplastics and their associated toxic chemical compounds pose significant risks to both terrestrial and aquatic ecosystems. Risk evaluation commonly relies on three indices: the Pollution Load Index (PLI), Polymer Hazard Index (PHI), and Potential Ecological Risk Index (PERI), with each providing valuable yet isolated insight into different aspects of microplastics risk. The study areas included three urban creeks located in Southeast Queensland, Australia. Based on data obtained from individual sampling sites and multiple sampling rounds, PLI, PHI and PERI hotspot locations were identified. PHI and PERI values indicated a strong influence of hazardous polymer composition on toxicity-weighted ecological risk. Site-level Spearman correlation analysis showed that industrial, commercial, and residential land uses are positively associated with PLI, PHI, and PERI, whereas natural land use showed a negative correlation. A risk-zoning framework was developed based on elbow and silhouette analyses, which identified k = 3 as the optimal number of clusters, defining low, medium, and high-risk groups. Eight risk categories were then derived from these groups for finer operational risk classifications. These were expressed using a consistent hexadecimal colour scale derived from the 40 possible index-combination permutations. The resulting two-dimensional (2D) risk-zoning plots visualise how sediment microplastics are distributed across the combined risk space. Film and foam were identified as the most dominant shape compositions across all risk categories. The proposed innovative methodology offers a practical approach for identifying microplastic hotspots, interpreting risk-driving mechanisms, and supporting decision-making and policy formulation for targeted microplastics management and ecological protection strategies.

Prioritizing Emerging Contaminants in Tropical Riverine Systems: An Integrated Approach Using Ecological and Human Health Risk Indices.

Emerging contaminants of concern (CECs) are increasingly detected in tropical riverine systems, yet their prioritization remains challenging due to data gaps, complex mixtures, and limited integration of ecological and human health perspectives. This study proposes an integrated framework to identify priority CECs by combining occurrence data, ecological risk quotients (RQ), human health hazard quotients (HQ), and a novel prioritization index (PI). Thirty-four (34) multiclass CECs, including pharmaceuticals, hormones, and plasticizers, were quantified in four rivers in Johor, Malaysia using optimized solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Caffeine (1511-6085 ng/L), paracetamol (32-7408 ng/L), and bisphenol A (344-837 ng/L) dominated the contaminant profiles. Most pharmaceuticals posed negligible ecological risk, while bisphenol A showed low ecological risk under worst-case exposure (0.01 < RQ < 0.1). In contrast, human health assessment indicated substantial risks from bisphenol A and bisphenol S, particularly for children (HQ > 1). Integration of ecological thresholds (PNEC) and reference doses (RfD) identified bisphenol analogues as highest-priority contaminants, followed by estrone, lidocaine, dexamethasone, and diphenhydramine. The framework demonstrates that concentration-based assessments may underestimate risk and supports toxicity-weighted prioritization for monitoring and regulation in tropical aquatic systems.

How harmless are alternative bioplastics? A review of their toxicological outcomes in aquatic organisms.

Multicriteria Prioritization of Emerging Contaminants in Agricultural Ditch Systems across China

Agricultural ditches play an underappreciated role in accumulating or attenuating waterborne emerging contaminants (ECs) from farmlands to downstream aquatic ecosystems. Here, we present the first nationwide assessment of ECs in ditches across major agricultural regions of China, through analyzing over 300 compounds at 183 sampling sites. A multicriteria assessment framework was applied to prioritize contaminants along the farmland ditch–river continuum by integrating scenario-specific occurrence patterns, transferable environmental fate properties, and toxicological profiles covering cytotoxicity, ecotoxicity, and human health endpoints. Principal component analysis was used to derive data-driven weights from the nationally representative data set, enabling objective synthesis of commonly used risk dimensions while reflecting the agricultural ditch context, avoiding the subjectivity of expert-assigned scoring. The prioritization identified per- and polyfluoroalkyl substances (PFASs) as the highest-priority pollutants owing to their extreme persistence, bioaccumulation potential, and human health risks, followed by several pesticides (notably tebuconazole and fipronil), bisphenol A, di-n-octyl phthalate, and natural hormones. Cluster analysis revealed two distinct pathways to high priority: source-intensive contaminants driven by continuous agricultural inputs and legacy-type persistent chemicals attributed to intrinsic molecular stability. Over 60% of the top-ranked substances appear on international regulatory watch lists, including those of China, the EU, and the US EPA, confirming the framework’s practical relevance. Beyond providing priority rankings for agricultural ditch management, our methodology offers a transparent and adaptable template for contaminant prioritization in other environmental settings.

Model-dependent variability in environmental exposure assessment of engineered nanomaterials: A comparison of material flow analysis and multimedia environmental fate models.