Comment on the paper 'Soil microplastic pollution under different land uses in tropics, southwestern China'

Research on soil microplastics is currently at an early stage, and there is no widely approved sampling protocol. Even so, any basic research should minimize errors to ensure that they are not amplified in future research. This paper examines some weaknesses of the original research paper 'Soil microplastic pollution under different land uses in tropics, southwestern China' recently published in this journal. The authors neglected to report the equipment used for soil sampling and did not use field blank samples. There is also a soil layer that was incorrectly named. The type and pore size of filter paper used for filtration during pre-analytical soil sample preparation is very important. In this paper the nature of the filter paper used, and its larger pore sizes are questionable by today's scientists. In addition, the authors in the original paper also overlooked reporting the statistical package used for statical analysis and ensuring if all data sets obey normality, homogeneity, and equality before running the one-way ANOVA test. This statistical step is widely considered mandatory, especially in the soil science community. So, this makes it difficult to trust the results documented. Furthermore, in the original paper, the needle and stereo microscope instruments used to sort microplastic-like materials prior to proper analysis are not reliable.

Automated summary

This article critically examines the weaknesses of a recent research paper on soil microplastic pollution in southwestern China. The authors failed to report essential details such as equipment used for soil sampling, the use of field blank samples, and misnaming a soil layer. Furthermore, the choice of filter paper and the omission of statistical analysis package and data set checks undermine the credibility of the research. Additionally, the reliability of the instruments used for sorting microplastic-like materials was called into question.