TY - JOUR

T1 - Behavior of microplastics and plastic film residues in the soil environment: A critical review

AU - Qi, Ruimin

AU - Jones, Davey L.

AU - Li, Zhen

AU - Liu, Qin

AU - Yan, Changrong

N1 - Validated without post-print. Added too late to save and without post-print. No response to repeated requests for version.

PY - 2020/2/10

Y1 - 2020/2/10

N2 - It is now widely acknowledged that microplastic pollution represents one of the greatest anthropogenically mediated threats to Earth-system functioning. In freshwater and marine ecosystems the presence of large amounts of microplastic appears almost ubiquitous, with frequent reports of negative impacts on aquatic health. In contrast, however, the impact of plastic in terrestrial environments remains poorly understood. In agroecosystems, microplastics (particles < 5 mm) can enter the soil environment either directly (e.g. from biosolids application, irrigation water, atmospheric deposition), or indirectly through the in situ degradation of large pieces of plastic (e.g. from plastic mulch films). Although we have encouraged the use of plastics over the last 50 years in agriculture to promote greater resource use efficiency and food security, the legacy of this is that many soils are now contaminated with large amounts of plastic residue (ca. 50–250 kg ha−1). Due to difficulties in separating and quantifying plastic particles from soil, our knowledge of their behavior, fate and potential to transfer to other receptors (e.g. surface and groundwater, air) and enter the human food chain remains poor. This information, however, is critical for evaluating the risk of soil-borne microplastic pollution. In this critical review, we systematically summarize (i) the distribution and migration of microplastics in soils, (ii) highlight the separation, extraction, and identification methods for monitoring microplastics in soils, (iii) discuss the ecological effects and pollution mechanisms of soil microplastics, (iv) propose mitigation strategies to help prevent and reduce microplastic pollution, and (v) identify the most important future challenges in soil microplastics research.

AB - It is now widely acknowledged that microplastic pollution represents one of the greatest anthropogenically mediated threats to Earth-system functioning. In freshwater and marine ecosystems the presence of large amounts of microplastic appears almost ubiquitous, with frequent reports of negative impacts on aquatic health. In contrast, however, the impact of plastic in terrestrial environments remains poorly understood. In agroecosystems, microplastics (particles < 5 mm) can enter the soil environment either directly (e.g. from biosolids application, irrigation water, atmospheric deposition), or indirectly through the in situ degradation of large pieces of plastic (e.g. from plastic mulch films). Although we have encouraged the use of plastics over the last 50 years in agriculture to promote greater resource use efficiency and food security, the legacy of this is that many soils are now contaminated with large amounts of plastic residue (ca. 50–250 kg ha−1). Due to difficulties in separating and quantifying plastic particles from soil, our knowledge of their behavior, fate and potential to transfer to other receptors (e.g. surface and groundwater, air) and enter the human food chain remains poor. This information, however, is critical for evaluating the risk of soil-borne microplastic pollution. In this critical review, we systematically summarize (i) the distribution and migration of microplastics in soils, (ii) highlight the separation, extraction, and identification methods for monitoring microplastics in soils, (iii) discuss the ecological effects and pollution mechanisms of soil microplastics, (iv) propose mitigation strategies to help prevent and reduce microplastic pollution, and (v) identify the most important future challenges in soil microplastics research.

KW - Environmental risk

KW - Nanoplastics

KW - Soil heath

KW - Mulching film

KW - Plasticizer

U2 - 10.1016/j.scitotenv.2019.134722

DO - 10.1016/j.scitotenv.2019.134722

M3 - Review article

VL - 703

JO - Science of the Total Environment

JF - Science of the Total Environment

SN - 0048-9697

M1 - 134722

ER -