Systematic assessment of the mechanisms and risks of micro- and nanoplastic particle exposure in marine invertebrates

Marine invertebrates are among the most vulnerable organism groups to micro- and nanoplastic (MNP) exposure, yet understanding of their interspecies sensitivity and mechanistic responses remains limited. This study provides a systematic evaluation of MNP toxicity across diverse marine invertebrate taxa by (i) evaluating the effects of MNP exposure on key biological endpoints as a function of key particle characteristics, and (ii) constructing species sensitivity distributions (SSDs) to derive ecologically relevant hazard thresholds. Data were extracted from the Toxicity of Microplastic Explorer (ToMEx) for Aquatic Organisms database (version 2.0), with quality evaluated using the Technical and Risk Assessment "Red" Criteria framework to ensure the inclusion of essential experimental parameters. Chronic no-observed-effect concentration (NOEC) values, derived from mortality, fitness, and functional-related endpoints, were analyzed as a function of particle size (nanoplastics: