Detection and Characterization of Multiple Microplastics in the Human Retina

Microplastics (MPs) are widespread emerging environmental pollutants that present significant health risks to humans. While the presence of MPs has been documented in various human tissues, the detection of MP residues in the human retina remains uncertain. Herein, we characterized the types and concentrations of MPs in 12 post-mortem human retinal samples via pyrolysis gas chromatography–mass spectrometry. The size, shape, and morphologies of MP particles in another two post-mortem human retinal samples were further characterized using laser direct infrared spectroscopy and scanning electron microscopy. MPs were detected in all 12 human retinal samples at concentrations ranging from 8.93 to 91.05 μg/g with an average concentration of 49.21 μg/g. Various MPs such as polystyrene (PS), polyethylene (PE), polypropylene (PP), poly(methyl methacrylate), and polyvinyl chloride (PVC) were identified, with PS, PE, PP, and PVC detected in all analyzed samples. The diameters of the MPs detected in the human retinal samples predominantly ranged from 20 to 50 μm, with most particles exhibiting fragmented or fibrous morphologies. This study presents the first detailed qualitative and quantitative analyses of MPs in the human retina, which provides a crucial foundation for future research assessing their potential risks and detrimental impacts on retinal health.