Prevalence of microplastics in the marine environment of Qatar's exclusive economic zone

Microplastics are now firmly recognized as a ubiquitous and growing global threat to marine biota, as well as their associated ecology and habitats. The prevalence of microplastics in the marine waters within Qatar’s Exclusive Economic Zone (EEZ) was investigated. Following sample extraction, microplastics were characterized using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, and the polymer type then verified using OMNIC Spectra Library. Synthetic polymer microplastics were identified in seawater sampled from ten out of twelve marine monitoring stations, with varying shapes and sizes. Granular shaped microplastics present ranged from 120µm to 1.2mm in size, and fibrous microplastic ranged from 150µm to 10mm. Polypropylene (PP), low density polyethylene (LDPE), polyethylene (PE), polystyrene (PS), polyamide (PA), acrylonitrile butadiene styrene (ABS), polymethyl methacrylate (PMMA) and cellophane microplastic particles were identified. Copolymers were also identified from the collected samples, including poly(styrene:vinylidene chloride), poly(ethylene:propylene:diene) and alkyd resin e.g. paint debris. The most numerous type of synthetic polymer microplastic identified was polypropylene, with the greatest concentration found near Halul Island in the north east of the Qatar EEZ, where nearby anthropogenic activities include oil-rig installations and shipping operations. In addition, as par to the investigation, an optimized method was also developed for the extraction of microplastics from seawater samples rich in phytoplankton. The use of 1M NaOH proved to be more efficient digestion treatment than 10M NaOH and 22.5M HNO3 solutions, as the latter two solutions resulted in structural damage and discoloration of the reference polymers: polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polystyrene (PS), polyethylene (PE), and nylon

Prevalence of microplastics in the marine waters of Qatar

The issue of plastic pollution in the marine environment is of increasing global concern. As plastics typically have an intrinsic durability, water insolubility and slow degradation rates, debris has now become both ubiquitous and persistent in the marine environment. Overtime, plastic ultimately result in the generation of microplastics via photolytic, thermal and biological degradation processes. Although the potential threat of microplastics on marine ecosystems is well recognized, there is no baseline data available for the Arabian Gulf. The Environmental Science Center of Qatar University has now documented the first evidence for the prevalence of microplastics within the Arabian Gulf, specifically in the marine waters of Qatar Exclusive Economic Zone (EEZ). Qatar has an arid climate and is situated midway along the western coast of the semi-enclosed Arabian Gulf. Qatar's coastline is particularly susceptible to marine debris due to the county's rapid urbanization and economic development. Surface seawater samples were collected from 12 stations during May 2015 research cruise of the RV Janan. An optimized and validated protocol was developed for the extraction of microplastics from plankton-rich samples without loss of microplastics present. Plankton present in seawater samples may readily mask the identification of microplastics and lead to an underestimation of the quantity of microplastics present. The protocol involved sample digestion using solutions of 1M NaOH, 10M NaOH, and 16M HNO3 in conjunction at different temperatures. Twenty mL of each solution was spiked with known quantities of reference polymer pellets, of varying diameters (63 μm to 4.70 mm) and used to digest the plankton biomass. The use of 1M NaOH proved to be a more efficient digestion treatment than 10M NaOH and 16M HNO3 solutions. Although 10M NaOH, and 16M HNO3 have been proven effective to mineralize plankton biomass, these solutions also resulted in some structural damage and discoloration of reference polymers with a low pH tolerance: polyvinyl alcohol, polyvinyl chloride, polystyrene, polyethylene, and nylon. After extraction, the microplastics were characterized using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy. In total 30 microplastics were isolated from the mineralized samples, with an average concentration of 0.71 particles m− 3 (range 0–3 particles m− 3). Nine out of 30 were identified as polypropylene, with the majority either granular, sizes ranging from 125 μm to 1.82 mm, or fibrous, sizes from 150 μm to 15.98 mm. Microplastics were more prevalent in areas where nearby anthropogenic activities, including oil-rig installations and shipping operations, are present.qscienc

Androgenic and Estrogenic Response of Green Mussel Extracts from Singapore’s Coastal Environment Using a Human Cell-Based Bioassay

In the last decade, evidence of endocrine disruption in biota exposed to environmental pollutants has raised serious concern. Human cell-based bioassays have been developed to evaluate induced androgenic and estrogenic activities of chemical compounds. However, bioassays have been sparsely applied to environmental samples. In this study we present data on sex hormone activities in the green mussel, Perna viridis, in Singapore’s coastal waters. P. viridis is a common bioindicator of marine contamination, and this study is a follow-up to an earlier investigation that reported the presence of sex hormone activities in seawater samples from Singapore’s coastal environment. Specimens were collected from eight locations around the Singapore coastline and analyzed for persistent organic pollutants (POPs) and heavy metals. Tissue extracts were then screened for activities on androgen receptors (ARs) and estrogen receptors (ER-α and ER-β) using a reporter gene bio-assay based on a HeLa human cell line. Mussel extracts alone did not exhibit AR activity, but in the presence of the reference androgenic hormone dihydrotestosterone (DHT), activities were up to 340% higher than those observed for DHT alone. Peak activities were observed in locations adjacent to industrial and shipping activities. Estrogenic activities of the mussel extract both alone and in the presence of reference hormone were positive. Correlations were statistically investigated between sex hormone activities, levels of pollutants in the mussel tissues, and various biological parameters (specimen size, sex ratio, lipid and moisture content). Significant correlations exist between AR activities, in the presence of DHT, and total concentration of POPs (r = 0.725, p < 0.05)

Chlorinated paraffins : a review of analysis and environmental occurrences.

Chlorinated paraffins (CPs), as technical mixtures of polychlorinated alkanes (PCAs), are ubiquitous in the environment. CPs tend to behave in a similar way to persistent organic pollutants (POPs), leading several countries to impose regulations on the use of CPs. In this article, we review the literature on the properties of CPs, the current analytical tools available to determine CPs in various types of environmental matrices, and concentrations found in the environment. In particular, concentrations of CPs in environmental compartments including air, water, sediments, biota, human food products and human tissues are summarized. Priorities for future research are: improvements in analytical methodologies (reducing the complexity of the analysis, producing reference materials and performing interlaboratory studies); determining background levels of chlorinated paraffins in the environment and human populations (this question should be answered using quality assured analytical tools allowing the intercomparison of data); and investigating the sources of CPs to the environment and to humans. Chlorinated paraffins (CPs), as technical mixtures of polychlorinated alkanes (PCAs), are ubiquitous in the environment. CPs tend to behave in a similar way to persistent organic pollutants (POPs), leading several countries to impose regulations on the use of CPs. In this article, we review the literature on the properties of CPs, the current analytical tools available to determine CPs in various types of environmental matrices, and concentrations found in the environment. In particular, concentrations of CPs in environmental compartments including air, water, sediments, biota, human food products and human tissues are summarized. Priorities for future research are: improvements in analytical methodologies (reducing the complexity of the analysis, producing reference materials and performing interlaboratory studies); determining background levels of chlorinated paraffins in the environment and human populations (this question should be answered using quality assured analytical tools allowing the intercomparison of data); and investigating the sources of CPs to the environment and to humans

Prevalence of microplastics in the marine waters of Qatar

Microplastics are firmly recognized as a ubiquitous and growing threat to marine biota and their associated marine habitats worldwide. The evidence of the prevalence of microplastics was documented for the first time in the marine waters of Qatar's Exclusive Economic Zone (EEZ). An optimized and validated protocol was developed for the extraction of microplastics from plankton-rich seawater samples without loss of microplastic debris present and characterized using Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy. In total 30 microplastic polymers have been identified with an average concentration of 0.71 particles m− 3 (range 0–3 particles m− 3). Polypropylene, low density polyethylene, polyethylene, polystyrene, polyamide, polymethyl methacrylate, cellophane, and acrylonitrile butadiene styrene polymers were characterized with majority of the microplastics either granular shape, sizes ranging from 125 μm to 1.82 mm or fibrous with sizes from 150 μm to 15.98 mm. The microplastics are evident in areas where nearby anthropogenic activities, including oil-rig installations and shipping operations are present.Scopu

Recovery and pre-treatment of fats, oil and grease from grease interceptors for biodiesel production

Fats, oil and grease (FOG) can be recovered efficiently from grease interceptors for biodiesel production. FOG is susceptible to hydrolysis because of its inherent high moisture content and the presence of lipases associated with food residuals in the grease interceptors. This study reveals that the FFA content of FOG derived from grease interceptors did not exceed 8% (w/w) due to constant influx of fresh FOG from wastewater. However, if the FOG is allowed to hydrolyze without dilution, the FFA content can reach 15% (w/w) in more than 20 days. Experiments were conducted to optimize reaction parameters for the esterification of FOG prior to the conventional alkali-catalyzed biodiesel production process. Sulphuric acid (H2SO4) was a more efficient catalyst than Fe2(SO4)3 in reducing the acid value to [less-than-or-equals, slant]1 mg KOH/g under identical reaction conditions. At reaction temperatures of [less-than-or-equals, slant]50 °C, only H2SO4 was capable of reaching the recommended acid value within 24 h. The optimum methanol to FFA ratio for an H2SO4-catalyzed reaction was 20:1, whereas for Fe2(SO4)3 it was above 26:1. Esterification occurred under static, non-mixed conditions, although conversion rates were low. The rate of conversion increased with mixing speed, with a 200 rpm orbital shaking speed as optimum.Biodiesel Fatty acid methyl esters Esterification Grease interceptors FOG

Organochlorine pesticides and heavy metals in Green Mussel, Perna viridis, in Singapore.

The green mussel, Perna viridis, was used to measure bioaccumulated levels of organochlorine pesticides (OCPs), together with various heavy metals, in the marine environment of Singapore. Samples were collected from eight different locations in the coastal waters of Singapore between April and May 2002. OCPs (i.e. DDT, Chlordane, Mirex, hexachlorobenzene (HCB), pentachloronitrobenzene (PCNB) and Heptachlor) were quantified by gas chromatography-mass spectrometry. Heavy metals (i.e. As, Cd, Cr, Cu, Ni, Pb and Zn) were quantified by induced coupled plasma spectrometry. The concentration ranged from 2.6 to 54 ng g-1 dw for DDTs (i.e. sum of p,p'-DDT, p,p'-DDD, o,p'-DDE and p,p'-DDE), 3.1 to 15 ng g-1 dw for Chlordanes (i.e. sum of α- and γ-chlordane) and 0.26 to 1.5 ng g-1 dw for Mirex. These levels can be considered low when compared to reported values from similar studies conducted elsewhere in the world. Other pesticides were not detected. All heavy metals analysed were detected in all P. viridis samples, but only Cu, Pb, Zn and As were close to existing safety standards. Samples taken from locations adjacent to the main shipyards on the coastline and busy shipping lanes demonstrated peak levels of heavy metals and pesticides in the mussel tissues

Occurrence of polychlorinated biphenyls and polybrominated diphenyl ethers in green mussels (Perna viridis) from Singapore, southeast Asia.

The green mussel, Perna viridis, was used in this study to measure levels of polychlorinated biphenyls (PCBs) and, for the first time, polybrominated diphenyl ethers (PBDE) in the marine environment. Samples were collected from eight different locations in the coastal waters of Singapore between April and May 2002. Forty-one PCB and 21 PBDE congeners were quantified by gas chromatography–mass spectrometry and were all positively detected in the mussel tissues. Total concentrations in green mussel tissues ranged from 6.1 to 82 ng/g and 2.0 to 38 ng/g on a dry-weight basis for PCBs and PBDEs, respectively. Such levels reflect the ubiquity of these persistent organic pollutants in a tropical marine environment. Principal component analysis was applied to the PCB data and revealed similarities in the congener composition of mussel tissues to that of the commercial PCB mixture, Aroclor 1254. The PBDE levels, to date, were approximately one order of magnitude greater than the upper concentrations reported for blue mussel (Mytilus edulis) tissues in Europe. At some sampling sites, the congener composition of PBDEs in P. viridis tissues indicated recent exposure to a commercial pentabrominated flame retardant