Micro- and nanoplastics: organ-specific toxicity, molecular pathways, and implications for human and environmental health

Environmental toxicology is increasingly focused on the growing concern of micro- and nanoplastic (MNPL) contamination. With plastics such as polypropylene (PP), polyvinyl chloride (PVC), polyethylene (PE), polyamide (PA), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), and polytetrafluoroethylene (PTFE) now widely detected in terrestrial, aquatic, and marine environments, as well as within human tissues and food products, the scope of the problem is profound. Recent research highlights that the size, morphology, and polymer type of MNPLs strongly influence their interaction with biological systems and their potential for harm. While laboratory and epidemiological studies increasingly document the capacity of MNPLs to induce oxidative stress, inflammation, metabolic disruption, genotoxicity, and even tumorigenesis, key questions remain about how these diverse polymer types, shapes, and their mixtures with environmental chemicals drive harmful outcomes. Furthermore, the ability of smaller, nanoplastic particles to cross biological barriers and distribute across organ systems, as well as their interactions with environmental co-contaminants like heavy metals and phthalates, add further complexity to their toxicological profiles.Current evidence reveals that MNPL exposure activates molecular signaling pathways implicated in inflammation, organ dysfunction, metabolic disorders, and carcinogenesis—including NF-κB, PI3K/AKT/mTOR, and Nrf2/HO-1, as well as inflammasomes. Studies now link MNPLs to microbiome disruption and the dysregulation of critical systemic axes, such as the gut–liver and gut–lung connections, all of which may contribute to the observed health risks. However, most research to date has focused on select polymers, like polystyrene, under simplified laboratory conditions, and does not fully reflect environmental diversity or chronic, low-dose human exposures. The lack of standardized methodologies and translational models hinders our ability to robustly assess MNPL effects and develop relevant health policies.This Research Topic aims to elucidate the organ-specific toxicity and carcinogenic potential of diverse micro- and nanoplastics, and to define the molecular, cellular, and multi-system mechanisms underlying their harmful effects. It seeks to clarify how polymer composition, particle size, morphological type (fibers, fragments), and co-exposure to environmental contaminants interact to shape toxicity, cancer risk, and system-wide physiological disruption. By advancing next-generation methodological tools, omics approaches, and realistic models—including translational and epidemiological frameworks—we aim to generate actionable insights for risk assessment, mitigation, and public health protection.Research within this topic is limited to studies focusing on the toxicology, mechanistic biology, and health implications of environmentally relevant micro- and nanoplastics, including their interactions with co-contaminants and their effects on major organ systems. We encourage investigations spanning in vivo, in vitro, ex vivo, and epidemiological paradigms, as well as the development or application of innovative models and techniques. To further our understanding, we welcome articles addressing, but not limited to, the following themes:- MNPL-induced oxidative stress, inflammation, genotoxicity, and carcinogenicity- Organ-specific toxicity in gut, liver, kidney, reproductive, cardiovascular, and nervous systems- Molecular signaling, omics-based findings, and pathways associated with MNPL toxicity and cancer risk- Synergistic toxicities arising from MNPLs and environmental co-contaminants- Microbiome alterations and disruptions of inter-organ systemic axes (e.g., gut–liver, gut–lung)- Realistic exposure assessment involving multiple polymers, shapes, and sizes in authentic environmental samples- Regulation, mitigation, and translational approaches to safeguard public healthWe invite original research articles, reviews, and perspectives, particularly those emphasizing authentic environmental MNPLs, standardized methodologies, and innovative, translational strategies. Topic editors: Mohamed Alaraby, Rute Isabel Cesário, Ricard Marcos, Naouale El Yamani Source: https://www.frontiersin.org/research-topics/77257/micro--and-nanoplastics-organ-specific-toxicity-molecular-pathways-and-implications-for-human-and-environmental-health