Cryosphere as a temporal sink and source of microplastics in the Arctic region

• Published in: Geoscience Frontiers
• Main Authors: Zhang, Yulan, Gao, Tanguang, Kang, Shichang, Allen, Deonie, Wang, Zhaoqing, Luo, Xi, Yang, Ling, Chen, Jinlei, Hu, Zhaofu, Chen, Pengfei, Du, Wentao, Allen, Steve
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2023
• Subjects: Environmental engineering; Arctic; arctic cryosphere; Arctic Ocean; Greenland; Ice; Ice Sheet; permafrost; Sea ice
• Online Access: https://strathprints.strath.ac.uk/85248/; https://strathprints.strath.ac.uk/85248/1/Zhang_etal_GF_2023_Cryosphere_as_a_temporal_sink_and_source_of_microplastics.pdf; https://doi.org/10.1016/j.gsf.2023.101566

Microplastics (MPs) pollution has become a serious environmental issue of growing global concern due to the increasing plastic production and usage. Under climate warming, the cryosphere, defined as the part of Earth's layer characterized by the low temperatures and the presence of frozen water, has been experiencing significant changes. The Arctic cryosphere (e.g., sea ice, snow cover, Greenland ice sheet, permafrost) can store and release pollutants into environments, making Arctic an important temporal sink and source of MPs. Here, we summarized the distributions of MPs in Arctic snow, sea ice, seawater, rivers, and sediments, to illustrate their potential sources, transport pathways, storage and release, and possible effects in this sentinel region. Items concentrations of MPs in snow and ice varied about 1–6 orders of magnitude in different regions, which were mostly attributed to the different sampling and measurement methods, and potential sources of MPs. MPs concentrations from Arctic seawater, river/lake water, and sediments also fluctuated largely, ranging from several items of per unit to >40,000 items m−3, 100 items m−3, and 10,000 items kg−1 dw, respectively. Arctic land snow cover can be a temporal storage of MPs, with MPs deposition flux of about (4.9–14.26) × 108 items km−2 yr−1. MPs transported by rivers to Arctic ocean was estimated to be approximately 8–48 ton/yr, with discharge flux of MPs at about (1.65–9.35) × 108 items/s. Average storage of MPs in sea ice was estimated to be about 6.1×1018 items, with annual release of about 5.1×1018 items. Atmospheric transport of MPs from long-distance terrestrial sources contributed significantly to MPs deposition in Arctic land snow cover, sea ice and oceanic surface waters. Arctic Great Rivers can flow MPs into the Arctic Ocean. Sea ice can temporally store, transport and then release MPs in the surrounded environment. Ocean currents from the Atlantic brought high concentrations of MPs into the Arctic. However, there existed large uncertainties of ...