The rapid increases in microplastics in urban lake sediments

Abstract

Anthropocene 8,27,33,35 , but there is still lack of sufficient studies about (micro)plastics abundance and characteristics versus time. We selected the second-largest urban lake in China, Donghu Lake, as the study area and collected a sediment column. The MPs with a detection limit of 100 μm versus time were studied by the 210 Pb chronological data, Raman Spectrometer identification and scanning electron microscope. The changes in MPs abundance, length, colour, polymer type, and surface features over time were studied, and the possibility of using MPs as an indicator of the Anthropocene was discussed.

The Paleoecology of Microplastic Contamination

“…Although data are more sparse for freshwaters than for marine systems, these processes are likely to result in the substantial accumulation of microplastics in lake sediments (Woodall et al, 2014;Tekman et al, 2020) and research shows that microplastic concentrations in freshwaters and their sediments are comparable to those in marine environments (Corcoran et al, 2015;Ballent et al, 2016;Klein et al, 2018). Furthermore, as observed by Dong et al (2020) and Turner et al (2019), downcore variations in microplastic abundance and polymer-type can be observed in lake sediments and may reflect changes in plastic production and usage, providing a temporal perspective to our understanding of microplastic inputs to lakes which has, to date, been underexplored.…”

“…Most recently, two further studies have been produced, both from China. First, Dong et al (2020) produced a microplastics profile from Donghu in Wuhan, Hubei Province. Here, fibers were the only microplastictype found to be present but their increasing concentrations, through the lake sediment record since 1960, showed a very good agreement with global synthetic fiber production.…”

“…Here, even where sampling points are selected far from the shore there remains a higher potential for disturbance from a range of anthropogenic impacts, including dredging, construction and a wide range of catchment activities. These may result in an altered distribution of contaminants within sediments as well as compromised accumulation and chronologies (Dong et al, 2020). Although urban, shallow water systems can be difficult ones from which to recover undisturbed sediment cores, when they are obtained, they can provide valuable records of microplastic pollution as well as a wide range of other anthropogenic contaminants over the recent historical period (Turner et al, 2019;Dong et al, 2020).…”

Environmental Microplastic Particles vs. Engineered Plastic Microparticles—A Comparative Review

“…Mao et al, who investigated both coastal and open water, found that fibres were the most dominant type, especially in the open-water fishing zones, with PS and PP being the most abundant polymer types [ 56 ]. Dong et al, 2020 inspected deep core lake sediment samples, in order to investigate microplastic particle sedimentation over time [ 57 ]. All of their MPs were fibres, in deep sediments exclusively made out of rayon and PET; while, in more recent years, the polymer types became more diverse with PET still being the most dominant.…”

Reactions of sciences to the Anthropocene

“…This so-called Great Acceleration (Steffen et al, 2011, pp. 849-853;Steffen et al, 2015a) is characterized by an exponential increase of, for example, new chemicals synthesized and marketed (Binetti et al, 2008) and volumes of microplastic released in ecosystems (Dong et al, 2020), as well as massive biodiversity losses and a permanent change of climate. Third, human influence on the entire Earth system is largely irreversible and a point of no return, for example, on global warming, will soon be reached (Lenton et al, 2019).…”