Department of Civil & Environmental Engineering, Ehime University, Matsuyama, Japan; Center for Marine Environmental Studies, Ehime University, Matsuyama, Japan.
Department of Civil & Environmental Engineering, Ehime University, Matsuyama, Japan.
Water Res. 2024 Sep 1;261:122061. doi: 10.1016/j.watres.2024.122061. Epub 2024 Jul 8.
The quantification of the mass of meso/microplastic (MMP) particles is crucial for assessing the global inventory of ocean plastics and assessing environmental and human health risks. Herein, linear regression models between mass and projected surface area on a log scale were established by directly measuring the masses of 4390 MMP particles collected at 35 sites in 17 Japanese rivers with an ultramicrobalance. The linear regression models estimated mass concentrations more accurately than any previous method based on geometric volume assuming several three-dimensional shapes. Additionally, linear regression models were quite reasonable for determining the geometric relationships of idealized cuboid particles. The slope of the linear regression models was dependent on the three-dimensional shapes of the particles, and their intercept was determined according to their third dimension. Moreover, the third dimension led to uncertainty in the mass estimation of particles; thus, the accuracies of the previous methods were relatively poor. Nevertheless, two limitations for mass measurement by linear regression models were identified, which determined the size range of the MMP particles on the projected surface area (ranging from 10 mm to 10 mm) that is applicable for mass estimation of the particles collected from riverine and marine environments. Our results could be used to accurately estimate the mass concentrations in aquatic environments and provide insights into the geometric relationships between the mass and size of MMP particles.
中/微塑料（MMP）颗粒质量的量化对于评估全球海洋塑料存量和评估环境及人类健康风险至关重要。在此，通过使用超微量天平直接测量在日本 17 条河流的 35 个采样点收集的 4390 个 MMP 颗粒的质量，建立了质量与对数标度上的投影表面积之间的线性回归模型。与基于假设几种三维形状的几何体积的任何先前方法相比，线性回归模型更准确地估计了质量浓度。此外，线性回归模型对于确定理想化长方体颗粒的几何关系也相当合理。线性回归模型的斜率取决于颗粒的三维形状，而其截距则根据它们的第三个维度确定。此外，第三个维度导致对颗粒质量估计的不确定性，因此，先前方法的准确性相对较差。尽管如此，仍确定了线性回归模型进行质量测量的两个限制因素，这决定了适用于从河流和海洋环境中收集的颗粒的质量估计的投影表面积上的 MMP 颗粒的尺寸范围（范围为 10 毫米至 10 毫米）。我们的结果可用于准确估计水生环境中的质量浓度，并深入了解 MMP 颗粒的质量与尺寸之间的几何关系。
