Exploring possible controlling factors of spatial distribution of microplastics in sediments of a river segment (Loire River, France).

Microplastics (MP) have been reported in many rivers across the globe but their depositional and archiving mechanisms in sediments are not fully understood yet. The aim of this study was to identify potential controlling factors of MP spatial distribution in surface sediment after a characterisation (sediment composition, hydrological conditions, sedimentary environment) of 14 sampling sites in an 8 km segment of the Loire river. Samples were collected from 3 sedimentary environments (sandbars, riverbanks and semi-active channels) with diverse flooding frequencies, grain size distributions and total organic carbon (TOC) contents.

Anthropogenic particle abundance and characteristics in seawater and intertidal sediments of the Tonkin Bay Coast (North Vietnam).

Microplastics (MPs, plastic items from 1 µm to 5 mm in size) are present in all environmental compartments. The evaluation of their concentration, fate, and spatial distribution is still a challenge for the scientific community. This concern is just debuting in developing countries, (i.

Time-varying microplastic contributions of a large urban and industrial area to river sediments.

The quantification of microplastic (MP) pollution in rivers is often constrained by a lack of historical data on a multi-decadal scale, which hinders the evaluation of public policies. In this study, MP contents and trends were analyzed in dated sediment cores sampled upstream and downstream of a large metropolis, in environmental deposits that exhibited consistent sedimentation patterns from the 1980s to 2021. After a thorough sedimentological analysis, MPs were quantified in samples by micro Fourier Transform InfraRed spectroscopy (μFTIR imaging) and a density separation and organic matter digestion procedure.

Microplastic trapping in dam reservoirs driven by complex hydrosedimentary processes (Villerest Reservoir, Loire River, France).

Dam reservoirs can strongly influence the spatial distribution of sediment pollution by microplastics (MP). The Villerest reservoir (Loire River, 36 km long) is a good candidate to study the relationship between MP pollution and hydrosedimentary processes. Sediments were collected from the dam-controlled river section and from 3 km downstream.

Dynamics of metallic contaminants at a basin scale--Spatial and temporal reconstruction from four sediment cores (Loire fluvial system, France).

From the 19th century, the Loire basin (France) presents potentially pollutant activities such as mining and heavy industries. This paper shows spatio-temporal distribution of trace elements in sediments at a basin-scale, based on a comparison of archived temporal signals recorded in four sedimentary cores. Anthropogenic sources contributing to sediment contamination are also characterized, using geochemical signatures recorded in river bank sediments of the most industrialized tributaries.