Distribution Of Microplastics In Sediments Research Articles

Spatial distribution of microplastics in sediments and surface waters of the southern North Sea

Microplastic pollution within the marine environment is of pressing concern globally. Accordingly, spatial monitoring of microplastic concentrations, composition and size distribution may help to identify sources and entry pathways, and hence allow initiating focused mitigation. Spatial distribution patterns of microplastics were investigated in two compartments of the southern North Sea by collecting sublittoral sediment and surface water samples from 24 stations. Large microplastics (500−5000 μm) were detected visually and identified using attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy. The remaining sample was digested enzymatically, concentrated onto filters and analyzed for small microplastics (11−500 μm) using Focal Plane Array (FPA) FTIR imaging. Microplastics were detected in all samples with concentrations ranging between 2.8 and 1188.8 particles kg−1 for sediments and 0.1–245.4 particles m−3 for surface waters. On average 98% of microplastics were <100 μm in sediments and 86% in surface waters. The most prevalent polymer types in both compartments were polypropylene, acrylates/polyurethane/varnish, and polyamide. However, polymer composition differed significantly between sediment and surface water samples as well as between the Frisian Islands and the English Channel sites. These results show that microplastics are not evenly distributed, in neither location nor size, which is illuminating regarding the development of monitoring protocols.

Microplastics in the surface seawaters of Chabahar Bay, Gulf of Oman (Makran Coasts)

Current study aimed to evaluate the microplastics abundance in the surface waters of Chabahar Bay for the first time. 21 neuston net water samples were collected from 7 stations. Microplastics were visually counted by stereomicroscope, sorted into 4 size categories, 4 shape categories, and identified by ATR-FTIR spectroscopy. Density of microplastics varied from 0.07 ± 0.03 to 1.14 ± 0.27 with an average density of 0.49 ± 0.43 particle·m−3. Microplastics were mostly found in the shape of fibers. 69% of analyzed particles were polyethylene and polypropylene. Main colors of the collected microplastics were white, blue and red. The results showed that the largest number of microplastics was found at station near populated area. Therefore, it can be concluded that, there is a pressing-need to investigate the distribution of microplastics in sediments and biota of this Bay as well as their effects on marine life and human health.

Microplastic pollution in sediments from the Bohai Sea and the Yellow Sea, China

Microplastics are one of the most significant pollutants in the marine environment and accumulate in sediments all over the world. To assess the pollution level in the marine environment in China, the distribution and abundance of microplastics in sediments from the Bohai Sea and the Yellow Sea were investigated in this study. The sediment samples were collected from 72 different sites in the Bohai Sea and the Yellow Sea. Microplastics were separated from sediment through density flotation and categorized according to shape and size under a microscope. Additionally, polymer types were identified using Fourier-Transform Infrared Micro-spectroscopy (μ-FT-IR). Our study demonstrated that microplastics were consistently found in all samples, which emphasized their extensive distribution throughout the Bohai Sea and the Yellow Sea. The average microplastic abundance was 171.8, 123.6 and 72.0 items per kg of dry weight sediment for the Bohai Sea, Northern Yellow Sea and Southern Yellow Sea, respectively. Among the sampled microplastics, fiber (93.88%) and small microplastics (<1000 μm) (71.06%) were the most frequent types. Fourier transform infrared microspectroscopy (μ-FT-IR) analysis determined that the main types of microplastics were rayon (RY), polyethylene (PE) and polyethylene terephthalate (PET). Our results highlighted the widespread distribution of microplastics in sediments from the Bohai Sea and the Yellow Sea and provided useful information for evaluating the environmental risks of microplastics in China.

Microplastics in sediments: A review of techniques, occurrence and effects

Microplastics are omnipresent in the marine environment and sediments are hypothesized to be major sinks of these plastics. Here, over 100 articles spanning the last 50 year are reviewed with following objectives: (i) to evaluate current microplastic extraction techniques, (ii) to discuss the occurrence and worldwide distribution of microplastics in sediments, and (iii) to make a comprehensive assessment of the possible adverse effects of this type of pollution to marine organisms. Based on this review we propose future research needs and conclude that there is a clear need for a standardized techniques, unified reporting units and more realistic effect assessments.

Occurrence and spatial distribution of microplastics in sediments from Norderney

The spatial distribution of small potential microplastics (SPM) (<1 mm) in beach sediments was studied on a 500 m stretch of the North Sea island of Norderney. Their correlation with visible plastic debris (VPD) (>1 mm) was also examined. Small microparticles were extracted from 36 one kg sediment samples and analysed by visual microscopic inspection and partly by thermal desorption pyrolysis gas chromatography/mass spectrometry. The smallest particle size that could be analysed with this method was estimated to be 100 μm. The mean number of SPM at the three sampling sites (n = 12) was 1.7, 1.3 and 2.3 particles per kg dry sediment, respectively. SPM were identified as polypropylene, polyethylene, polyethylene terephthalate, polyvinylchloride, polystyrene and polyamide. The organic plastic additives found were benzophenone, 1,2-benzenedicarboxylic acid, dimethyl phthalate, diethylhexyl phthalate, dibutyl phthalate, diethyl phthalate, phenol and 2,4-di-tert-butylphenol. Particles were distributed rather homogenously and the occurrence of SPM did not correlate with that of VPD.