Effects of micro and nano plastics on renal health.

Research on microplastics (MPs) and kidney health is rapidly expanding, yet major knowledge gaps remain. Human exposure remains poorly characterized, with limited data on MPs levels in drinking water, food, indoor air, urine, blood, and kidney tissues. Most animal models rely on high-dose, short-term exposures, whereas studies employing environmentally realistic doses and long-term designs are required to evaluate links with chronic kidney disease and fibrosis. Mechanistic insights are also incomplete; the roles of ferroptosis, pyroptosis, and complement activation, as well as the influence of particle size, shape, polymer type, and surface charge, warrant further investigation. Co-exposures are another critical issue, as MPs act as vectors for heavy metals, persistent organic pollutants, and plastic additives, while also interacting with the gut microbiota and immune system. Clinical implications are particularly concerning: Dialysis fluids, intravenous solutions, and medical devices may represent unrecognized sources of exposure. Addressing these gaps will require multidisciplinary approaches, harmonized detection methods, and clinical monitoring to assess the burden and health consequences of MPs in vulnerable populations. This review underscores the kidney as a potential target organ for MP accumulation and highlights the urgent need for human biomonitoring.