Environmental Micro-Nanoplastics and Musculoskeletal Disorders: Current Research and Insights

In recent years, micro-nanoplastics, as globally prevalent emerging environmental pollutants, can enter the human body through oral ingestion, respiratory inhalation, and dermal contact, and widely distribute in diverse tissues including blood, placenta, lung, bone marrow, and bone, thereby arousing widespread concern regarding their health risks. As an essential functional system of the human body, the skeletal system is involved in mechanical support, metabolic homeostasis, and immune regulation. Disruption of skeletal homeostasis may induce a series of musculoskeletal diseases, such as osteoporosis, rheumatoid arthritis, intervertebral disc degeneration, and osteoarthritis. Accumulating evidence has verified that micro-nanoplastics can accumulate in human bone, cartilage, intervertebral disc, and bone marrow, and destroy skeletal homeostasis via multiple mechanisms, including inflammatory response, oxidative stress, pyroptosis, ferroptosis, cellular senescence, and epigenetic regulation, thus participating in the occurrence and development of musculoskeletal diseases. This paper systematically reviews the sources, classification, environmental distribution, human exposure pathways, and systemic toxic effects of micro-nanoplastics. It emphatically expounds the impacts and potential molecular mechanisms of micro-nanoplastics on osteoporosis, intervertebral disc degeneration, rheumatoid arthritis, osteoarthritis, lupus-related musculoskeletal lesions, and osteosarcoma progression. Furthermore, we summarize the detection methods and research limitations of micro-nanoplastics in skeletal tissues, and prospect future directions in environmental prevention and control, clinical translation, and high-risk population monitoring. This review is expected to provide novel ideas for mechanistic investigation, risk assessment, and clinical translation of micro-nanoplastic-associated skeletal diseases.