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Uptake of polycyclic aromatic hydrocarbons and their cellular effects in the mangrove Bruguiera gymnorrhiza
2016
Naidoo, Gonasageran | Naidoo, Krishnaveni
The uptake of polycyclic aromatic hydrocarbons and their cellular effects were investigated in the mangrove Bruguiera gymnorrhiza. Seedlings were subjected to sediment oiling for three weeks. In the oiled treatment, the ƩPAHs was higher in roots (99%) than in leaves (1%). In roots, PAHs included phenanthrene (55%), acenaphthene (13%), fluorine (12%) and anthracene (8%). In leaves, PAHs possessed two to three rings and included acenaphthene (35%), naphthalene (33%), fluorine (18%) and phenanthrene (14%). In the roots, oil caused disorganization of cells in the root cap, meristem and conducting tissue. Oil contaminated cells were distorted and possessed large and irregularly shaped vacuoles. Ultrastructural changes included loss of cell contents and fragmentation of the nucleus and mitochondrion. In the leaves, oil caused dilation and distortion of chloroplasts and disintegration of grana and lamellae. Oil targets critical organelles such as nuclei, chloroplasts and mitochondria which are responsible for cell vitality and energy transformation.
Mostrar más [+] Menos [-]Hazards in hanging gardens: A report on failures of recognition by green turtles and their conservation implications
2016
de Carvalho-Souza, Gustavo Freire | de A. Miranda, Daniele | Pataro, Luciano
Marine species are experiencing unprecedented global impacts due to anthropogenic debris. Many recent studies have pointed out the hazards associated with marine litter ingestion, especially plastic debris – the most abundant and ubiquitous items in coastal and oceanic environments worldwide. In this study we provide the first in situ evidence of consumption of non-discarded synthetic rope fragments by green turtles. We explored the environmental risks to this endangered species associated with the grazing and consumption of anthropogenic debris in zones of human activity. Efforts to combat debris ingestion and reduce anthropogenic debris discharged into the world's oceans should be a priority for decision-makers and will need to involve multiple-approaches and the adoption of more environmentally friendly products and practices by the international community.
Mostrar más [+] Menos [-]Effect analysis on regeneration speed of continuous regeneration-diesel particulate filter based on NO2-assisted regeneration
2016
E, Jiaqiang | Xie, Longfu | Zuo, Qingsong | Zhang, Guiju
In order to improve the regeneration speed of Continuous Regeneration-Diesel Particulate Filter (CR-DPF) based on NO2-assisted regeneration, a mathematic model of the NO2-assisted regeneration is developed and verified by experiments and numerical simulation. Furthermore, the influences on regeneration speed from exhaust airflow and filter structure are studied in NO2-assisted regeneration process of CR-DPF. The results show that: the regeneration speed will be increased due to the increase of the volume of the exhaust gas, the temperature of the exhaust gas, the concentration of the NO2 and the concentration of the O2 in exhaust gas, but the regeneration speed will be decreased under other conditions such as m(NO2)/m(PM) being less than its threshold in exhaust gas, the increase of the filter length in CR-DPF or the increase of the channel density when initial amount of the carbon particles in filter being less than its threshold, moreover, thickness of channel wall has no effect on regeneration speed. And the suitable range of values for some key parameters being useful for enhancing regeneration speed and reducing pressure drop of CR-DPF has been provided.
Mostrar más [+] Menos [-]FTIR spectroscopy supported by statistical techniques for the structural characterization of plastic debris in the marine environment: Application to monitoring studies
2016
Mecozzi, Mauro | Pietroletti, Marco | Monakhova, Yulia B.
We inserted 190 FTIR spectra of plastic samples in a digital database and submitted it to Independent Component Analysis (ICA) to extract the “pure” plastic polymers present. These identified plastics were polypropylene (PP), high density polyethylene (HDPE), low density polyethylene (LDPE), high density polyethylene terephthalate (HDPET), low density polyethylene terephthalate (LDPET), polystyrene (PS), Nylon (NL), polyethylene oxide (OPE), and Teflon (TEF) and they were used to establish the similarity with unknown plastics using the correlation coefficient (r), and the crosscorrelation function (CC). For samples with r<0.8 we determined the Mahalanobis Distance (MD) as additional tool of identification. For instance, for the four plastic fragments found in the Carretta carretta, one plastic sample was assigned to OPE due to its r=0.87; for all the other three plastic samples, due to the r values ranging between 0.83 and0.70, the support of MD suggested LDPET and OPE as co-polymer constituents.
Mostrar más [+] Menos [-]Assessment of perfluorooctanoic acid and perfluorooctane sulfonate in surface water - Tamil Nadu, India
2016
Sunantha, Ganesan | Vasudevan, Namasivayam
As an emerging class of environmentally persistent organic pollutants, perfluorinated compounds (PFCs), particularly perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS); have been universally found in the environment. Wastewater and untreated effluents are likely the major causes for the accumulation of PFCs in surface water. There are very few reports on the contamination of PFCs in the developing countries, particularly in India. This study reports the quantitative analysis of PFOA and PFOS in Noyyal, Cauvery, and also lakes in and around Chennai, using Ultra-Fast liquid chromatograph. The concentration of PFOA and PFOS ranged from 4 to 93ng/L and 3 to 29ng/L, respectively. The concentration of PFOS was below detectable limit in Cauvery River. A reliable concentration of PFOA was recorded at all sites of River Cauvery (5ng/L). The present study could be useful for the assessment of future monitoring programs of PFOA and PFOS in the surface water.
Mostrar más [+] Menos [-]Absence of selenium protection against methylmercury toxicity in harbour seal leucocytes in vitro
2016
Dāsa, Kr̥shṇā | Dupont, Aurélie | De Pauw-Gillet, Marie- Claire | Debier, Cathy | Siebert, Ursula
Previous studies described high concentrations of mercury (Hg) and selenium (Se) in the blood of harbour seals, Phoca vitulina from the North Sea. In the present study, we evaluated the in vitro potential protective effects of sodium selenite (Na2SeO3) and selenomethionine (SeMet) on cell proliferation of harbour seal lymphocytes exposed to MeHgCl 0.75μM. In vitro exposure of ConA-stimulated T lymphocytes resulted in severe inhibition of DNA synthesis, likely linked to severe loss of mitochondrial membrane potential at 0.75μM. Neither selenite nor SeMet showed a protective effect against MeHg toxicity expressed at the T lymphocyte proliferation level for harbour seals. Selenite and SeMet did not show negative effects regarding lymphocyte proliferation and mitochondrial membrane potential.To conclude, our results clearly demonstrated that MeHg affected in vitro immune cells exposure with no protective effects of selenium at a molar ratio Hg:Se of 1:10 in harbour seals from the North Sea.
Mostrar más [+] Menos [-]Addressing aquatic hazard classification for metals, metal compounds and alloys in marine systems
2016
Huntsman-Mapila, P. | Skeaff, J.M. | Pawlak, M. | Beaudoin, R.
New International Maritime Organization regulations require shippers to classify all solid bulk cargo to indicate whether they are Harmful to the Marine Environment (HME). The objective of this work was to adapt the freshwater Transformation/Dissolution Protocol (T/DP) to marine water to provide a method to determine, when compared with marine Ecotoxicity Reference Values (ERVs), whether a metal-bearing substance is HME. The substances examined were: Cu2O powder; Ni metal powder; Co3O4 powder; and a Ni–Co–Fe alloy, as wire cuttings, which were the same substances examined in the freshwater T/D validation study and afforded comparisons of the reactivity, or measure of the rate and extent of metal release from the metal-bearing substances in freshwater versus marine conditions. The marine T/D method is suitable for conducting examinations of metal-bearing substances with a wide range of reactivities, from the relatively reactive Cu2O powder and the alloy to the Co3O4 powder, which was the least reactive.
Mostrar más [+] Menos [-]Baseline concentration of Polonium-210 (210Po) in tuna fish
2016
Khan, M Feroz | Wesley, S Godwin
Several species of tuna fish were analyzed for 210Po content in their edible muscle tissues. This study was carried out as a part of baseline data generation around a large nuclear power plant situated at Kudankulam, southeast coast of India. The concentration of 210Po in the muscle tissue ranged from 40.9±5.2 to 92.5±7.9Bq/kg of fresh fish, and the highest activity was recorded for the tuna Euthynnus affinis and the lowest for Auxis thazard. The committed effective dose to the local residents was calculated to be 62.7–141.8μSvyear−1.
Mostrar más [+] Menos [-]Cadmium concentration in liver and muscle of silky shark (Carcharhinus falciformis) in the tip of Baja California south, México
2016
Terrazas-López, Rafael | Arreola-Mendoza, Laura | Galván-Magaña, Felipe | Anguiano-Zamora, Marlene | Sujitha, S.B. | Jonathan, M.P.
Cadmium concentrations were determined in the tissues of muscle and liver of Carcharhinus falciformis (silky shark) sampled in Todos Santos, Baja California South, Mexico. This is one of the main shark species for human consumption in Mexico. Results indicate that accumulation of Cd varied in both sexes, based on its metabolism, sex, maturity and other biological characteristics. High Cd values were observed in the liver of adults of male (529.61μgg−1) and female (457.43μgg−1), whereas, in muscular tissues it was low (0.37μgg−1) than the prescribed permissible limits for seafood (0.5μgg−1). Substantial correlations were observed between body length and Cd values in adults except young male due to faster growth rate and its metabolism. The study indicated the impact of environmental conditions in the accumulation of Cd and its risk to the food web structure in the marine environment and health hazard for humans.
Mostrar más [+] Menos [-]Factors controlling the origin of Cochlodinium polykrikoides blooms along the Goheung coast, South Korea
2016
Lee, Moon Ock | Kim, Jong Kyu | Kim, Byeong Kuk
We investigated the factors influencing the origin of Cochlodinium polykrikoides blooms along the Goheung coast (GH), and compared them to those along the Geoje (GJ) coast and in the East China Sea (ECS) which were used as reference sites. Stratification did not develop in GH during C. polykrikoides blooms, unlike that in GJ. The surface salinity during summer in ECS was equivalent to that of GH, whereas surface temperature and concentration of nutrients in ECS were markedly higher than those in GH or GJ. Thermohaline (or thermal) fronts appeared between the Korea Southern Coastal Water (KSCW) and the outer seawater during C. polykrikoides blooms. The result of numerical simulation models indicated that freshwater from the Yangtze River clearly affected KSCW. As a result, the origin of C. polykrikoides blooms in GH during summer could be attributed to the inflow of seawater from ECS with high water temperature and abundant nutrients.
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