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Effect of natural exposure on plastic fiber in the disposable surgical aged mask components (outer layer (figures a, b, c, d), middle layer (figures e, f, g, h), inner layer (figures i, j, k, l) and ear ribbon (figures m, n, o, p)). Electron microscopy resolution of 3.66 μm (1 mm) and 1.46 μm (0.4 mm).
