Microplastics (MPs)
Also known as: MPs · PET particles · polypropylene fragments · polystyrene beads · polyethylene particles
Overview
Plastic particles between 1 micrometer and 5 millimeters in diameter, derived from the fragmentation of larger plastic items or manufactured at small size (primary microplastics). Microplastics have now been detected in human blood, lung tissue, placenta, breast milk, and — critically — directly inside PBMCs. The PBMC intracellular burden of microplastics is a particularly important clinical indicator because it represents particles that have been phagocytosed by macrophages and monocytes, triggering persistent sterile inflammation. The chemical complexity of microplastics is compounded by the dozens of additives (plasticizers, flame retardants, stabilizers, colorants) that leach from the plastic matrix and are co-detected by HRMS.
Primary Sources
Bottled water (a primary source — studies find hundreds to thousands of particles per liter), food packaging and containers, synthetic clothing fibers (released during washing), sea salt, seafood, indoor dust, personal care products (microbeads), agricultural plastic mulch films degrading in soil, atmospheric fallout.
Health Effects
Sterile macrophage inflammation and NLRP3 inflammasome activation, oxidative stress, endocrine disruption from co-leaching plasticizers (phthalates, bisphenols), gut microbiome disruption, potential carcinogenicity, immune dysregulation, and reproductive toxicity. Detected in human placentas and associated with adverse birth outcomes.
Detection Method
This toxin is detected and quantified using HRMS (LC or GC) analysis of isolated PBMCs. The intracellular accumulation of this compound in lymphocytes and monocytes provides a more accurate reflection of chronic systemic burden than conventional serum or urine testing.