(Micro)plastics
from erosion control engineering
in China: Environment pollution and
prevention strategies
Haoxin Hao1, 2, Fengling Yan1, 2,
Zhonglu Guo3*, Junguang Wang3,
Qiuxia Wang4, Cuiting Dai5, Cheng
Liu1
1Changjiang Water Resources Protection Institute,
Wuhan, PR China
2Key Laboratory of Ecological Regulation of Non-point
Source Pollution in Lake and Reservoir Water Sources, Changjiang Water
Resources Commission, Wuhan, P.R. China
3College of Resources and Environment, Huazhong
Agricultural University, Wuhan, PR China
4Yangtze Soil Conservation Monitoring Center,
Changjiang Water Resources Commission, Wuhan, PR China
5Hunan Academy of Agricultural Sciences, Changsha, PR
China
∗Corresponding author: Zhonglu Guo
Email: zlguohzau@163.com
Running title: Prevention (micro)plastic pollution in erosion control
engineering in China
Abstract
(Micro)plastics are ubiquitous in our daily lives and are becoming a
global emerging pollutant with significant threat to ecosystem
sustainability. Within the field of soil erosion control engineering
(ECE) in China, a wide range of plastic products, such as plastic mesh,
planting bags, and plastic geocells, are extensively employed to stable
the topsoil and facilitate the restoration of disturbed land. In this
paper, we demonstrate the wide distribution of (micro)plastics in ECE
across varied landscapes in China, highlighting their relatively high
degradation rate induced by ultraviolet irradiation and mechanical
disturbance. Furthermore, (micro)plastics in ECE exhibit a propensity
for transport through soil erosion processes, thereby heightening the
pollution risk to aquatic ecosystems. While the presence of
(micro)plastics in ECE raises significant environmental concerns, there
could be straightforward and easily implementable preventive strategies.
These strategies include meticulous managing plastic usage during the
design and completion phases of ECE, replacing plastic materials with
biodegradable alternatives, and cleaning and retrieving temporary work
materials.
KEY WORDS: Microplastic Pollution; Soil Erosion; Erosion
Control Engineering; Ecological Restoration; Prevention Strategies
Introduction
Plastics are increasingly
recognized as a significant threat to the sustainability of our
ecosystem (Thompson et al., 2009; Rillig & Lehmann 2012).
The extensive use and poor
management of plastics have resulted in their ubiquitous presence in our
daily lives, making them a globally emerging pollutant. Research efforts
have predominantly focused on the issue of small plastic debris,
particularly microplastics (defined as plastic particles <
5mm), which pose substantial risks to the global biosphere and human
health (Thompson et al., 2009; Horton et al., 2017). Previous studies
have overwhelmingly examined the
sources of microplastics originating from various plastic objects, such
as car tires, clothing, paint coatings, and agricultural mulching,
through weathering and breakdown processes (Xu et al., 2020; Chen et
al., 2022). However, the
potential contribution of (micro)plastics from civil engineering has yet
to be considered, even though the increasing use of plastic products as
alternatives to traditional materials like wood and steel.
In China, erosion control engineering (ECE) is a prioritized practice
for preventing soil erosion and restoring disturbed land during
construction activities, as mandated by the Soil and Water
Conservation Law . With this context,
various
of plastic products are
extensively employed in ECE to stable topsoil and facilitate the
restoration of disturbed land, particularly in slopes and
riverbanks. Consequently, the
excessive use of plastic materials in ECE has the potential to release
microplastics into the environment. Therefore, comprehending the sources
of (micro)plastics in ECE and their associated environmental risks is
crucial for informing measures to prevent and control microplastic
pollution. In this paper, we outline the characteristics of
(micro)plastic pollution originating from ECE in China and suggest
relevant prevention strategies through source control measures, which
are relatively straightforward and easily implemented.
Characteristics of (micro)plastic pollution in
ECE
2.1 Ubiquitous in construction and ecological restoration
projects of China
Plastics are ubiquitous in ECE
across China due to its affordability, durability and versatility.
Generally, plastic products are
used to prevent soil erosion by providing a physical barrier that
protect soils from raindrop impact and runoff scouring in temporary
work, and are used to stable slopes as well as promote vegetation growth
by providing a suitable environment for seed germination and root
development during permanent work. Since 1980s,
large-scale of plastic mulching
(e.g., plastic mesh) as well as
plastic reinforcement agent (e.g.,
plastic geocell) are extensively
employed to immediately control soil erosion and reinforcement topsoil
during intense construction
activity, e.g., road, rail, dam, mines (Figure.1 a-g). In recent years,
some so called ecological techniques, which indeed involved
incorporating plastics to soils (e.g., planting bag, non-woven
geotextile and blanket), are now highly encouraged in various
ecological
restoration projects to stable
channel, promote vegetation growth as well as to rehabilitation of rocky
slopes (Figure.1 e-i). Although plastic products have demonstrated
effectiveness in mitigating erosion and have a positive impact on
vegetation recovery and dust prevention, their large-scale and
widespread usage in soil could pose a potential risk of microplastic
pollution.