Occurrence characteristics and potential risk of microplastics under different land conditions

Yanhua Wang ¹, Na Xiao ¹, Zhibao Dong ¹

⁰School of Geography and Tourism, Shaanxi Normal University, Xi'an, 710119, China.

Environmental Pollution +

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May 31, 2024

View abstract on PubMed

Summary

Microplastic (MP) pollution is highest in farmland soil, decreasing with land restoration and varying by crop type. Polypropylene (PP) and polyethylene terephthalate (PET) are dominant MP types, posing moderate pollution risks.

Area Of Science

Environmental Science
Soil Science
Ecotoxicology

Background

Microplastic (MP) pollution is a growing global concern, particularly in agricultural soils.
Limited research exists on MP distribution across diverse land uses, restoration periods, and crop types.

Purpose Of The Study

To investigate the distribution characteristics of MPs in northern Shaanxi Province, China.
To evaluate the ecological risks associated with MP pollution in various soil environments.
To understand how land use, restoration age, and crop type influence MP contamination.

Main Methods

Soil samples were collected across different land use types, restoration years, and crop types.
Microplastic abundance, particle size, morphology, and polymer types were analyzed using Raman spectroscopy and Laser Direct Infrared (LDIR) spectroscopy.
Ecological risk was assessed using the Ecological Risk Index (H) and Pollution Load Index (PLI).

Main Results

Farmland soil exhibited the highest MP concentration (4483 items·kg⁻¹), significantly higher than industrial park soil.
MP abundance decreased with increased land restoration years, while smaller particle sizes became more prevalent.
Polypropylene (PP) and polyethylene terephthalate (PET) were the dominant polymer types, with sizes between 20-40 μm being most common. 51.9% of sites showed moderate pollution.
Perennial crops had more stable MP content and smaller particle sizes compared to annual crops.

Conclusions

Farmland soil presents the highest risk of microplastic pollution.
Land restoration and crop type significantly influence MP distribution and characteristics.
Understanding these factors is crucial for assessing and mitigating the ecological risks of microplastic contamination in agricultural ecosystems.

Keywords:

Crop types Land use Microplastics Potential risk Restoration years