Plastic and cellulose fibres contaminate the ecosystem. These are increasingly distinguished spectroscopically and their mass is estimated geometrically by melding data about their density, length, diameter and breadth. This is problematic because the shape and porosity of fibres vary, and spectroscopy cannot distinguish amongst celluloses. Light and electron microscopies can measure and distinguish amongst celluloses using transversal and longitudinal morphological features (e.g. twists, nodes, size, shape, pores) but they require physical sections that are not possible for micrometre-sized fibres. While forensic scientists have proposed using confocal microscopy to virtually section fibres, it is unknown if the virtual images can be used to distinguish and measure fibres. Here, we show that confocal microscopy can distinguish features and identify cellulosic fibres (cotton, linen, rayon-viscose, ramie, jute) but the virtual size of cellulosic and plastic fibres increased when the confocal image is compiled. By physically sectioning individual pristine and weathered cellulosic (cotton, rayon-viscose) and plastic (polyester, polyamide) fibres and then measuring transversal sections imaged by light and confocal microscopies, we revealed (i) the widths of fibres measured from confocal images were more accurate than their heights and areas; (ii) transversal areas estimated by the equation of an ellipse were more accurate than those estimated with a circular equation. Experimental addition of dibutyl phthalate polystyrene xylene to fibres showed it physically shrank the width of fibres of rayon-viscose and polyamide by 4–5% but not cotton and polyester. Finally, we used our confocal technique to identify cellulosic fibres found amongst oyster-beds and showed many were predominantly cotton. Our results are discussed in relation to improving the methods to better estimate the type, number, mass and volumes of fibres in environmental surveys.

塑料和纤维素纤维会污染生态系统。这些在光谱学上越来越突出，并且它们的质量是通过融合有关它们的密度，长度，直径和宽度的数据进行几何估计的。这是有问题的，因为纤维的形状和孔隙率变化，并且光谱学不能区分纤维素。光和电子显微镜可以使用横向和纵向形态特征（例如，扭曲，节，尺寸，形状，孔）在纤维素中进行测量和区分，但是它们需要的物理切片对于微米级的纤维而言是不可能的。虽然法医科学家建议使用共聚焦显微镜对纤维进行虚拟切片，但未知是否可以使用虚拟图像来区分和测量纤维。这里，我们显示，共聚焦显微镜可以区分特征并识别纤维素纤维（棉，亚麻，人造丝-粘胶纤维，麻，黄麻），但是当编译共聚焦图像时，纤维素纤维和塑料纤维的虚拟尺寸会增加。通过对原始的和风化的纤维素纤维（棉，人造丝粘胶纤维）和塑料纤维（聚酯纤维，聚酰胺纤维）进行物理切片，然后测量通过光和共聚焦显微镜成像的横截面，我们发现（i）从共聚焦图像中测得的纤维宽度更大比他们的身高和面积准确；（ii）由椭圆方程估算的横向面积比由圆形方程估算的横向面积更准确。将邻苯二甲酸二丁酯聚苯乙烯二甲苯添加到纤维中的实验表明，它在物理上将人造丝粘胶纤维和聚酰胺纤维的宽度缩小了4％到5％，而在棉花和聚酯纤维上却没有缩小。最后，我们使用共聚焦技术鉴定了在牡蛎床上发现的纤维素纤维，并发现其中许多纤维主要是棉花。我们讨论了有关改进方法以更好地估计环境调查中纤维的类型，数量，质量和体积的结果。