Advances in Evaluation Parameter Frameworks and Weighting Methods for the Prioritization of Emerging Contaminants

Emerging contaminants encompass a wide variety of substances, and the scientific identification of priority substances for control remains an important challenge in environmental management. Although numerous prioritization methods have been developed, differences in the emphasis placed on parameter selection and approaches to weight determination have resulted in an overlap of less than 10% among priority control lists in some studies, thereby reducing the consistency and comparability of assessment results. This review focuses on parameter selection and weighting methods in priority control assessment. The evolution of evaluation parameters is systematically summarized across three major dimensions: environmental exposure, toxicity risk, and environmental fate. The theoretical foundations, applicability, and limitations of subjective weighting, objective weighting, combined subjective-objective weighting, and intelligent algorithm-based screening methods are critically reviewed. Environmental exposure assessment is evolving from production/use volume and predicted environmental concentrations toward integrated characterization using measured environmental concentrations, detection frequencies, and exceedance probabilities, with predicted concentrations differing from measured values by more than one order of magnitude in some cases. Toxicity assessment is expanding from conventional acute toxicity endpoints toward class-specific risk characterization. Environmental fate assessment frameworks have also evolved from the traditional PBT (persistence, bioaccumulation, and toxicity) framework toward PMT (persistence, mobility, and toxicity) and vPvM (very persistent and very mobile) frameworks. Weighting approaches show an overall shift from single-method weighting toward combined optimization, while machine learning has further expanded capabilities for identifying indicator contributions and high-throughput screening. To address current limitations in data completeness, model interpretability, and policy applicability, several recommendations are proposed, including strengthening the measurement of key parameters, standardizing quantitative criteria for priority classification, adopting pollutant-specific evaluation strategies, and establishing standardized and shared databases. This review provides a scientific basis for the prioritization of emerging contaminants.