The occurrence of microplastic contamination in littoral sediments of the Persian Gulf, Iran

Microplastics (MPs; <5 mm) in aquatic environments are an emerging contaminant of concern due to their possible ecological and biological consequences. This study addresses that MP quantification and morphology to assess the abundance, distribution, and polymer types in littoral surface sediments of the Persian Gulf were performed. A two-step method, with precautions taken to avoid possible airborne contamination, was applied to extract MPs from sediments collected at five sites during low tide. MPs were found in 80% of the samples. Across all sites, fiber particles were the most dominate shape (88%), followed by films (11.2%) and fragments (0.8%). There were significant differences in MP particle concentration between sampling sites (p value <0.05). The sediments with the highest numbers of MPs were from sites in the vicinity of highly populated centers and municipal effluent discharges. FTIR analysis showed that polyethylene (PE), nylon, and polyethylene terephthalate (PET) were the most abundant polymer types. More than half of the observed MPs (56%) were in the size category of 1–4.7 mm length, with the remaining particles (44%) being in the size range of 10 μm to <1 mm. Compared to literature data from other regions, intertidal sediments in the Persian Gulf cannot be characterized as a hot spot for MP pollution. The present study could, however, provide useful background information for further investigations and management policies to understand the sources, transport, and potential effects on marine life in the Persian Gulf.

Abolfazl Naji, Zinat Esmaili, Sherri A. Mason, A. Dick Vethaak, Environmental Science and Pollution Research, pp 1–10, 14 July 2017

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The adverse effects of virgin microplastics on the fertilization and larval development of sea urchins

Highlights

• Toxicity of virgin PS and HDPE particles and their leachates was investigated.
• Virgin microplastics are toxic to sea urchin embryo through the leaching of chemicals.
• Our results highlight the necessity to wash or weather virgin microplastics before toxicity testing.

Concepción Martínez-Gómez, Víctor M. León, Susana Calles, Marina Gomáriz-Olcina, A. Dick Vethaak, Marine Environmental Research, Available online 30 June 2017, In Press

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Microplastics in the sediments of Terra Nova Bay (Ross Sea, Antarctica)

This is the first survey to investigate the occurrence and extent of plastic contamination in sediments collected in Terra Nova Bay (Ross Sea, Antarctica). Plastic debris extracted from 31 samples of sediments were counted, weighted and identified by Fourier-transform infrared spectroscopy (FT-IR). All sediment samples contained plastics: a total of 1661 items of debris (3.14 g) were recorded from the 31 samples of sediment. Plastic particles in the samples ranged from 0.3 to 22 mm in length. Fibres were the most frequent type of small plastics debris detected. In terms of abundance, microplastics (< 5 mm) accounted for 78.4% of debris. 9 polymer types were found: the most common material (94.13% by weight) was styrene-butadiene-styrene copolymer (SBS), widely used in pneumatic tires, etc. A decreasing concentration of plastic debris at increasing distances from the Mario Zucchelli Base was evidenced.

Cristina Munari, Vanessa Infantini, Marco Scoponi, Eugenio Rastelli, Cinzia Corinaldesi, Michele Mistri, Marine Pollution Bulletin, Available online 20 June 2017, In Press

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Microplastics found in waters off Qatar

The first evidence of prevalence of microplastics in Gulf seawater, specifically in the marine waters off Qatar, has been documented through a research study conducted by senior researchers from Qatar University Environmental Science Center (QU-ESC).
“Polypropylene microplastics were the most common type of plastic polymer found with most particles being either granular or fibrous in shape, with sizes from 125?m to 15.98mm”, said team leader and ESC’s former director and professor Dr Jeff Obbard.
Such microplastics are commonly associated with general plastic packaging waste, and marine fishing nets. He noted that the levels of microplastics found in Qatar’s marine waters are still relatively low compared to some other locations around the world, but vigilance is needed. (…) (gulf-times.com, 19/06/2017)

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The Impacts of Biofilm Formation on the Fate and Potential Effects of Microplastic in the Aquatic Environment

In the aquatic environment, Microplastic (MP; < 5 mm) is a cause of concern due to its persistence and potential adverse effects on biota. Studies on microlitter impacts are mostly based on virgin and spherical polymer particles as model MP. However, in pelagic and benthic environments, surfaces are always colonized by microorganisms forming so-called biofilms. The influence of such biofilms on the fate and potential effects of MP presents a current knowledge gap. Here, we review the physical interactions of early microbial colonization on plastic surfaces and their reciprocal influence on the weathering processes and vertical transport as well as sorption and release of contaminants by MP. Possible ecological consequences of biofilm formation on MP, such as trophic transfer of MP particles and potential adverse effects of MP, are virtually unknown. However, the evidence is accumulating that by modifying the physical properties of the particles, the biofilm-plastic interactions have the capacity to influence the fate and impacts MP may have. There is an urgent research need to better understand these interactions and increase ecological relevance of current laboratory testing by simulating field conditions where microbial life is a key driver of the biogeochemical processes.

Christoph D. Rummel, Annika Jahnke, Elena Gorokhova, Dana Kühnel, and Mechthild Schmitt-Jansen, Environ. Sci. Technol. Lett., 2017, 4 (7), pp 258–267

Characterization of plastic beach debris finalized to its removal: a proposal for a recycling scheme

Characterization of beach debris is crucial to assess the strategy to answer questions such as recycling. With the aim to assess its use in a recycling scheme, in this note, we carried out a physical and chemical characterization of plastic litter from a pilot beach in Central Italy, using the FT-IR spectroscopy and thermoanalysis. Fourteen polymers, having mainly thermoplastic origin, were identified; among them, the most represented are polyethylene (41.7%) and polypropylene (36.9%). Chemical and mechanical degradation were clearly observed by an IR spectrum. The thermogravimetric analysis curve of the plastic blend shows the melting point at 120–140 °C, and degradation occurs almost totally in a one-step process within 300–500 °C. The high heating value of the plastic debris is 43.9 MJ kg−1. Polymer blends obtained by beach debris show mechanical properties similar to the virgin high-density polyethylene polymer. Following the beach plastic debris characterization, a recycling scheme was suggested.

Loris Pietrelli, Gianluca Poeta, Corrado Battisti, Maria Sighicelli, Environmental Science and Pollution Research, 07 June 2017, pp 1–7

The plastic in microplastics: A review

Microplastics [MPs], now a ubiquitous pollutant in the oceans, pose a serious potential threat to marine ecology and has justifiably encouraged focused biological and ecological research attention. But, their generation, fate, fragmentation and their propensity to sorb/release persistent organic pollutants (POPs) are determined by the characteristics of the polymers that constitutes them. Yet, physico-chemical characteristics of the polymers making up the MPs have not received detailed attention in published work. This review assesses the relevance of selected characteristics of plastics that composes the microplastics, to their role as a pollutant with potentially serious ecological impacts. Fragmentation leading to secondary microplastics is also discussed underlining the likelihood of a surface-ablation mechanism that can lead to preferential formation of smaller sized MPs.

Anthony L. Andrady, Marine Pollution Bulletin, Volume 119, Issue 1, 15 June 2017, Pages 12–22

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