Microplastics and polycyclic aromatic hydrocarbons (PAHs) in Xiamen coastal areas: Implications for anthropogenic impacts

Microplastics and polycyclic aromatic hydrocarbons (PAHs) were investigated to study the influence of human activities and to find their possible relationship on the coastal environments, where the coastal areas around Xiamen are undergoing intensive processes of industrialization and urbanization in the southeast China. The abundance of microplastics in Xiamen coastal areas was 103 to 2017 particles/m3 in surface seawater and 76 to 333 particles/kg in sediments. Concentrations of dissolved PAHs varied from 18.1 to 248 ng/L in surface seawater. The abundances of microplastics from the Western Harbor in surface seawater and sediments were higher than those from other areas. Foams were dominated in surface seawater samples, however, no foams were found in sediments samples. The microscope selection and FTIR analysis suggested that polyethylene (PE) and polypropylene (PP) were dominant microplastics. The cluster analysis results demonstrated that fibers and granules had the similar sources, and films had considerably correlation with all types of PAHs (3 or 4-ring PAHs and alkylated PAHs). Plastic film mulch from agriculture practice might be a potential source of microplastics in study areas. Results of our study support that river runoff, watershed area, population and urbanization rate influence the distribution of microplastics in estuarine surface water, and the prevalence of microplastic pollution calls for monitoring microplastics at a national scale.

G. Tang, M. Liu, Q. Zhou and al., Science of The Total Environment, Volume 634, 1 September 2018, Pages 811-820

The article

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Sorption behaviors of phenanthrene on the microplastics identified in a mariculture farm in Xiangshan Bay, southeastern China

Recently, with the accumulation of evidence that microplastic can be ingested by a variety of marine organisms, microplastic sorption behaviors towards organic contaminants (OCs) have become the subject of more studies due to the concerns about the contaminant vector effect. In this study, the priority microplastics identified in a mariculture farm in Xiangshan Bay, China, including polyethylene (PE) and nylon fibers (i.e., derived from new fishing ropes and nets), were examined for their sorption behaviors. The results indicate that both plastic fibers show linear isotherms towards phenanthrene, a common target hydrophobic organic contaminant (HOC), revealing the characteristics of a partitioning mechanism. The sorption capacity of PE fiber was found to be 1–2 orders of magnitude higher (evaluated by Freundlich parameter log KF) than that of nylon fiber, suggesting the importance of plastic surface functional groups (i.e., with or without hydrophilic groups). By comparing carbon normalized log KF with literature data, the organic affinity of PE fiber was found to be 1–2 orders of magnitude lower than that of vectors, such as carbonaceous geosorbents (CG), but was 1–2 orders of magnitude higher than that of marine sediments. Small size and rough surface tended to enhance the sorption of plastic fibers of phenanthrene. In addition, phenol (log KOW: 1.46), a low-hydrophobicity compound, showed approximately 3 orders of magnitude lower sorption amounts onto both fibers compared to phenanthrene (log KOW: 4.46), indicating the selectivity of hydrophobicity. The results of this study demonstrate that the high abundance of plastic fibers distributed in mariculture farms could lead to a higher contaminant transfer effect than marine sediments, and their effects on cultured seafood (e.g., crab and fish) need further investigation.

Science of The Total Environment, Volumes 628–629, 1 July 2018, Pages 1617–1626
Zheng Wang, Minglong Chen, Liwen Zhang and al., Science of The Total Environment, Volumes 628–629, 1 July 2018, Pages 1617–1626

Characterization of microplastic litter in the gastrointestinal tract of Solea solea from the Adriatic Sea

Micro-plastic particles in the world’s oceans represent a serious threat to both human health and marine ecosystems. Once released into the aquatic environment plastic litter is broken down to smaller pieces through photo-degradation and the physical actions of waves, wind, etc. The resulting particles may become so small that they are readily taken up by fish, crustaceans and mollusks. There is mounting evidence for the uptake of plastic particles by marine organisms that form part of the human food chain and this is driving urgent calls for further and deeper investigations into this pollution issue.

The present study aimed at investigating for the first time the occurrence, amount, typology of microplastic litter in the gastrointestinal tract of Solea solea and its spatial distribution in the northern and central Adriatic Sea. This benthic flatfish was selected as it is a species of high commercial interest within the FAO GFCM (General Fisheries Commission for the Mediterranean) area 37 (Mediterranean and Black Sea) where around 15% of the overall global Solea solea production originates.

The digestive tract contents of 533 individuals collected in fall during 2014 and 2015 from 60 sampling sites were examined for microplastics. These were recorded in 95% of sampled fish, with more than one microplastic item found in around 80% of the examined specimens. The most commonly found polymers were polyvinyl chloride, polypropylene, polyethylene, polyester, and polyamide, 72% as fragments and 28% as fibers. The mean number of ingested microplastics was 1.73 ± 0.05 items per fish in 2014 and 1.64 ± 0.1 in 2015. PVC and PA showed the highest densities in the northern Adriatic Sea, both inshore and off-shore while PE, PP and PET were more concentrated in coastal areas with the highest values offshore from the port of Rimini.

G. Pellini, A. Gomiero, T. Fortibuoni and al., Environmental Pollution, Volume 234, March 2018, Pages 943–952

The article

Baseline evaluation of sediment contamination in the shallow coastal areas of Saudi Arabian Red Sea

Despite the growing recognition of the importance of water and sediment quality there is still limited information on contamination levels in many regions globally including the Red Sea. This study provides a comprehensive assessment of three classes of contaminants (Polycyclic Aromatic Hydrocarbons – PAH; metals; plastics) in coastal sediments along the Saudi Arabian Red Sea mainly collected using grabs. Background concentrations are provided for metals in the region. Concentrations of metals and PAH were generally low in comparison to international guidelines. A clear relationship between the concentration of metals and anthropogenic sources was not always apparent and dust and vegetation may be relevant players in the region. Microplastic items (mainly polyethylene) were abundant (reaching up to 1 g m− 2 and 160 pieces m− 2) and in general associated with areas of high human activity. This study provides critical information for future monitoring and the development of national policies within the Red Sea region.

Pedro Ruiz-Compean, Joanne Ellis, João Cúrdia, Richard Payumo, Ute Langner, Burton Jones, Susana Carvalho, Marine Pollution Bulletin, Available online 12 September 2017, In Press

The article

Impact of Polymer Colonization on the Fate of Organic Contaminants in Sediment

Plastic pellets and microbes are important constitutes in sediment, but the significance of microbes colonizing on plastic pellets to the environmental fate and transport of organic contaminants has not been adequately recognized and assessed. To address this issue, low-density polyethylene (LDPE), polyoxymethylene (POM) and polypropylene (PP) slices were preloaded with dichlorodiphenyltrichloroethanes (DDTs), polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) and incubated in abiotic and biotic sediment microcosms. Images from scanning electron microscope, Lysogeny Broth agar plates and confocal laser scanning microscope indicated that all polymer slices incubated in biotic sediments were colonized by microorganisms, particularly the LDPE slices. The occurrence of biofilms induced higher dissipation rates of DDTs and PAHs from the LDPE slice surfaces incubated in the biotic sediments than in the abiotic sediments. Plastic colonization on LDPE slice surfaces enhanced the biotransformation of DDT and some PAHs in both marine and river sediments, but had little impact on PCBs. By comparison, PP and POM with unique properties were shown to exert different impacts on the physical and microbial activities as compared to LDPE. These results clearly demonstrated that the significance of polymer surface affiliated microbes to the environmental fate and behavior of organic contaminants should be recognized.

Chen-Chou Wu, Lian-Jun Bao, Liang-Ying Liu, Lei Shi, Shu Tao, and Eddy Y. Zeng, Environ. Sci. Technol., 51 (18), pp 10555–10561, 2017

The article

Colour spectrum and resin-type determine the concentration and composition of Polycyclic Aromatic Hydrocarbons (PAHs) in plastic pellets

This study assessed the concentration and composition of Polycyclic Aromatic Hydrocarbons (PAHs) in plastic pellets, collected from sandy beaches and considered different resin and colour tones. Results showed that polyethylene pellets, while displaying a greater range of total PAH concentrations did not differ significantly from polypropylene pellets. More importantly, both resin types demonstrated predictable increases in total PAH across a spectrum of darkening colour tones. Multivariate comparisons of 36 PAH groups, further showed considerable variability across resin type and colour, with lighter coloured pellets comprising lower molecular weight, while darker pellets contained higher weight PAHs. Overall, we show predictable variation in PAH concentrations and compositions of plastic pellets of different ages and resin types that will directly influence the potential for toxicological effects. Our findings suggest that monitoring programs should take these attributes into account when assessing the environmental risks of microplastic contamination of marine and coastal habitats.

Mara Fisner, Alessandra Majer, Satie Taniguchi, Márcia Bícego, Alexander Turra, Daniel Gorman, Marine Pollution Bulletin, Available online 3 July 2017, In Press

The article

Acute water quality criteria for polycyclic aromatic hydrocarbons, pesticides, plastic additives, and 4-Nonylphenol in seawater

Probabilistic environmental quality criteria for Naphthalene (Nap), Phenanthrene (Phe), Fluoranthene (Flu), Pyrene (Pyr), Triclosan (TCS), Tributyltin (TBT), Chlorpyrifos (CPY), Diuron (DUR), γ-Hexaclorocyclohexane (γ-HCH), Bisphenol A (BPA) and 4-Nonylphenol (4-NP) were derived from acute toxicity data using saltwater species representative of marine ecosystems, including algae, mollusks, crustaceans, echinoderms and chordates. Preferably, data concerns sublethal endpoints and early life stages from bioassays conducted in our laboratory, but the data set was completed with a broad literature survey. The Water Quality Criteria (WQC) obtained for TBT (7.1·10−3 μg L−1) and CPY (6.6· 10−3 μg L−1) were orders of magnitude lower than those obtained for PAHs (ranging from 3.75 to 45.2 μg L−1), BPA (27.7 μg L−1), TCS (8.66 μg L−1) and 4-NP (1.52 μg L−1). Critical values for DUR and HCH were 0.1 and 0.057 μg L−1 respectively. Within this context, non-selective toxicants could be quantitatively defined as those showing a maximum variability in toxicity thresholds (TT) of 3 orders of magnitude across the whole range of marine diversity, and a cumulative distribution of the TT fitting to a single log-logistic curve, while for selective toxicants variability was consistently found to span 5 orders of magnitude and the TT distribution showed a bimodal pattern. For the latter, protective WQC must be derived taking into account the SSD of the sensitive taxa only.

I. Durán, R. Beiras, Environmental Pollution, Volume 224, May 2017, Pages 384–391

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