A temporal sediment record of microplastics in an urban lake, London, UK

Abstract

A radionuclide-dated ( 210 Pb and 137 Cs) sediment core collected from Hampstead Pond No. 1, a North London lake, was used to provide novel data on the historical accumulation of microplastic waste in the urban environment. Microplastics were extracted from sediments by sieving and dense-liquid separation. Fibres of anthropogenic origin dominated the assemblage. Microplastics were first identified by microscopy before Raman spectroscopy of selected particles was used to determine the composition of synthetic polymers and dyes. Polystyrene microplastic particles were identified, in addition to synthetic fibres of polyacrylonitrile, polyvinyl chloride and fibres containing synthetic dyes. Concentrations of total microplastics in the sediment samples ranged from detection level to 539 particles per kilogram of dried sediment. Proliferation of microplastics is evident in the core from the late 1950s to the present. Relatively low numbers of particles were found in older sediments, comparable to laboratory blanks, highlighting the difficulty of extending a plastic chronostratigraphy back to the early twentieth century. This study shows that, with optimisation, routine extraction of microplastics from radionuclide-dated lake sediments can add an important temporal perspective to our understanding of microplastics in aquatic systems.

Microplastics in Lake Mead National Recreation Area, USA: Occurrence and biological uptake

“…Concentrations in surficial sediment samples in the current study (87.5-1,010 particles/kg dw) are similar to those reported in the Milwaukee Harbor and nearshore Lake Michigan (Wisconsin, USA; 39.5-319 particles/kg dw) [60]; nearshore Lake Ontario (Canada; 40-4,270 particles/kg dw) [23]; and an urban lake in London (England; 539 particles/kg dw) [61]. The overlap in sediment microplastic concentrations between Lake Mead NRA and these more urbanized locations may point to a dispersed pathway such as atmospheric deposition of microplastic particles on the landscape [8,11,53].…”

Eulerian Modeling of the Three‐Dimensional Distribution of Seven Popular Microplastic Types in the Global Ocean

“…In the second experiment, a smaller value was chosen for w s , with a value of 30 m year −1 . Literature on the dynamics and timescales of plastic incorporation into both marine and freshwater sediments are limited (such as Corcoran et al, ; Gilligan et al, ; Turner et al, ; Wessel et al, ), particularly with regard to values which could be used as a global average, and so, our approach to modeling this process is very tentative. Using a piston velocity formulation to simulate plastic sedimentation leads to e ‐folding timescales for plastic removal that depend on the depth of the water column.…”

Sampling and Quality Assurance and Quality Control: A Guide for Scientists Investigating the Occurrence of Microplastics Across Matrices

“…Samples of deeper marine sediment have been obtained with benthic grabs and cores. 60,104,130,131 In marine sediment, 104 beach sand, 148 and lake/pond sediment, 65,153 higher concentrations of microplastics are present at shallow depths. The vertical distribution of microplastics in dated sediment cores may provide a means for reconstructing historical inputs and understanding fate and loss of microplastics to marine and aquatic systems, 60,143,153 as the vertical distribution of microplastics in sediment is not well understood.…”