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Front. Sustain. Food Syst.
Sec. Agroecology and Ecosystem Services
Volume 8 - 2024 | doi: 10.3389/fsufs.2024.1420628
This article is part of the Research Topic From Farm To Plate: Assessing Plastics And Microplastics Across The Value Chain Of Food Systems View all articles

Microplastics and cadmium pollution in Chinese sweet potato fields

Provisionally accepted
Liang Shi Liang Shi 1Zanming Chen Zanming Chen 1Binhao Liu Binhao Liu 1Yanan Hou Yanan Hou 1Jianmin Li Jianmin Li 1Fei Dang Fei Dang 2Yujun Wang Yujun Wang 2Zhenguo Shen Zhenguo Shen 1Yahua Chen Yahua Chen 1*
  • 1 Nanjing Agricultural University, Nanjing, China
  • 2 Institute of Soil Science, Chinese Academy of Sciences (CAS), Nanjing, Jiangsu Province, China

The final, formatted version of the article will be published soon.

    Context and background: Microplastic (MP) and heavy metal (HM) coexist in farmland of China. Motivation: It still remains unclear their exposure levels and distribution in sweet potato fields. Hypothesis: Polyethylene (PE) or polyamide (PA) is the main MP pollutant in contaminated sweet potato sites and the MP abundance in low latitude and eastern areas are highest. Methods: In this study, saturated NaCl solution, stereo microscope, Fourier transform infrared spectrometer, and Electrothermal digester are used for the extraction, observation, identification of MPs and analysis of Cd elements in soil, respectively. Results: Here, we found an average MP level at 112,400 items/kg in 30 sweet potato field sites based on the items in 5 g soil and the magnification (200x), and the maximum abundance is 197,153 items/kg in Laiyang city, Shandong province by field survey. The distribution characteristics of MPs are middle latitude areas < low latitude areas, and eastern areas > central areas.Most MPs are of the fragment and film shape, which account for 47.96% and 40.22% respectively. In order to detect MP polymers in three cities named "Liancheng", "Huanggang" and "Laiyang" with different degrees of development, a laser infrared imaging system as a novel instrument is used to explore the MPs which size is above 10 μm. Conclusions: The results showed that PA is the main MP pollutant in contaminated sweet potato sites, and soil texture, planting time, and urbanization process may be the main factors affecting MP distribution. The average cadmium (Cd) concentrations in 215 field sites is 0.15 mg/kg, and the local Cd pollution is existing, but the overall pollution is low. In addition, Cd concentration was negatively correlated with MP abundance. This study reveals the status of MP, and also Cd 3 pollution in sweet potato fields, which provide a theoretical basis for the safe production and utilization of sweet potato fields.

    Keywords: Cadmium, distribution, Field survey, Laser infrared imaging system, Polyamide

    Received: 20 Apr 2024; Accepted: 18 Jun 2024.

    Copyright: © 2024 Shi, Chen, Liu, Hou, Li, Dang, Wang, Shen and Chen. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Yahua Chen, Nanjing Agricultural University, Nanjing, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.