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Bioremediation potential of microorganisms derived from petroleum reservoirs Полный текст
2014
Dellagnezze, Bruna Martins | de Sousa, Gabriel Vasconcelos | Martins, Laercio Lopes | Domingos, Daniela Ferreira | Limache, Elmer E.G. | de Vasconcellos, Suzan Pantaroto | da Cruz, Georgiana Feitosa | de Oliveira, Valéria Maia
Bacterial strains and metagenomic clones, both obtained from petroleum reservoirs, were evaluated for petroleum degradation abilities either individually or in pools using seawater microcosms for 21days. Gas Chromatography–Flame Ionization Detector (GC–FID) and Gas Chromatography-Mass Spectrometry (GC–MS) analyses were carried out to evaluate crude oil degradation. The results showed that metagenomic clones 1A and 2B were able to biodegrade n-alkanes (C14 to C33) and isoprenoids (phytane and pristane), with rates ranging from 31% to 47%, respectively. The bacteria Dietzia maris CBMAI 705 and Micrococcus sp. CBMAI 636 showed higher rates reaching 99% after 21days. The metagenomic clone pool biodegraded these compounds at rates ranging from 11% to 45%. Regarding aromatic compound biodegradation, metagenomic clones 2B and 10A were able to biodegrade up to 94% of phenanthrene and methylphenanthrenes (3-MP, 2-MP, 9-MP and 1-MP) with rates ranging from 55% to 70% after 21days, while the bacteria Dietzia maris CBMAI 705 and Micrococcus sp. CBMAI 636 were able to biodegrade 63% and up to 99% of phenanthrene, respectively, and methylphenanthrenes (3-MP, 2-MP, 9-MP and 1-MP) with rates ranging from 23% to 99% after 21days. In this work, isolated strains as well as metagenomic clones were capable of degrading several petroleum compounds, revealing an innovative strategy and a great potential for further biotechnological and bioremediation applications.
Показать больше [+] Меньше [-]The distribution of heavy metals including Pb, Cd and Cr in Kendari Bay surficial sediments Полный текст
2014
Armid, Alrum | Shinjo, Ryuichi | Zaeni, Ahmad | Sani, Asrul | Ruslan, Ruslan
The surficial coastal sediments in Kendari Bay are sampled in the field to determine the concentration and pollution level of three heavy metals (Pb, Cd and Cr). Twenty-five sampling points ranging from the inner (Wanggu River) to the outer area of the bay have been chosen. The physicochemical properties, such as temperature, pH, salinity and TDS of the overlying water, as well as the sediment type and TOC of the surficial sediments, are also measured. The total concentrations of the Pb, Cd and Cr in the sediment samples are quantified using inductively-coupled plasma mass spectrometry (ICP-MS). The concentrations of the heavy metals (Pb, Cd and Cr) ranged from 0.84 to 17.02μg/g, 0.02 to 0.17μg/g and 1.92 to 40.11μg/g (dry weight), respectively, following the Cr>Pb>Cd sequence. To assess the degree of contamination, a geoaccumulation index (Igeo) is measured. Kendari Bay is not a contaminated area regarding Pb, Cd and Cr.
Показать больше [+] Меньше [-]Fishing down the largest coral reef fish species Полный текст
2014
Fenner, Douglas
Studies on remote, uninhabited, near-pristine reefs have revealed surprisingly large populations of large reef fish. Locations such as the northwestern Hawaiian Islands, northern Marianas Islands, Line Islands, U.S. remote Pacific Islands, Cocos-Keeling Atoll and Chagos archipelago have much higher reef fish biomass than islands and reefs near people. Much of the high biomass of most remote reef fish communities lies in the largest species, such as sharks, bumphead parrots, giant trevally, and humphead wrasse. Some, such as sharks and giant trevally, are apex predators, but others such as bumphead parrots and humphead wrasse, are not. At many locations, decreases in large reef fish species have been attributed to fishing. Fishing is well known to remove the largest fish first, and a quantitative measure of vulnerability to fishing indicates that large reef fish species are much more vulnerable to fishing than small fish. The removal of large reef fish by fishing parallels the extinction of terrestrial megafauna by early humans. However large reef fish have great value for various ecological roles and for reef tourism.
Показать больше [+] Меньше [-]Persistent organic pollutants in liver of Brazilian sharpnose shark (Rhizoprionodon lalandii) from southeastern coast of Brazil Полный текст
2014
Cascaes, M.J. | Oliveira, R.T. | Ubarana, M.M. | Sato, R.M. | Baldassin, P. | Colabuono, F.I. | Leonel, J. | Taniguchi, S. | Weber, R.R.
In the present study, persistent organic pollutants (POPs) were determined in 14 livers from specimens of the Brazilian sharpnose shark (Rhizoprionodon lalandii), which is an important economic resource for small-scale fisheries on the southeastern coast of Brazil. The following concentrations (lipid weight) of POPs were found: ∑PCBs: 1019±267ngg−1; ∑DDTs: 111±40ngg−1 and ∑PBDEs: 10.4±4.78. PCB 153 made the greatest contribution to ∑PCB (21.4%), followed by PCB 138 (14.6%) and PCB 180 (9.94%). Among chlorinated pesticides, only the p,p′-DDE and p,p′-DDD isomers had concentrations above the detection limit. Moreover, levels above the detection limit were found only for PBDE congeners 47 and 100 (BDEs 47>99). On average, BDE 47 accounted for 88% of the total PBDE load. The feeding habits of the Brazilian sharpnose shark close to the Brazilian coastline are likely the most important difference regarding the accumulation of POPs in comparison to oceanic species that feed in deeper waters. Thus, this species may be used to evaluate the pollution of coastal areas as well as human exposure to contaminants, as the Brazilian sharpnose shark is a frequently used for human consumption. Further studies in other areas of Brazil and involving other species are needed to clarify the mechanisms and potential impact of POPs, which can affect the biology of different organisms and cause population declines.
Показать больше [+] Меньше [-]Distribution of resting cysts of the potentially toxic dinoflagellate Alexandrium pseudogonyaulax in recently-deposited sediment within Bizerte Lagoon (Mediterranean coast, Tunisia) Полный текст
2014
Triki, Habiba Zmerli | Daly-Yahia, Ons Kéfi | Malouche, Dhafer | Komiha, Yosr | Deidun, Alan | Brahim, Mouldi | laabir, Mohamed
This study investigated the spatial distribution of Alexandrium pseudogonyaulax resting cysts in recently-deposited sediment of Bizerte lagoon (South-Western Mediterranean, Tunisia). This lagoon is the subject of many anthropogenic impacts, such as holding important fishing and aquaculture activities. A. pseudogonyaulax has been shown to produce Goniodomin A, which is a biologically-active compound. We showed that this dinoflagellate produces two types of resting cysts, which could be distinguished by the presence or the absence of a paratabulate wall. The average cyst density across the whole lagoon was rather high, reaching 639cystsg−1 of dry sediment (DS). Cyst densities varied widely among the sampled stations, with the highest density of 1685cystg−1DS being recorded at station 51 near a mussel farm. With respect to sediment characteristics, the highest cyst densities were found within silty sediments with high water content values. The distribution of A. pseudongoyaulax cysts in Bizerte lagoon appears to be related to hydrodynamic factors.
Показать больше [+] Меньше [-]Organohalogen contaminants and trace metals in North-East Atlantic porbeagle shark (Lamna nasus) Полный текст
2014
Bendall, Victoria A. | Barber, Jonathan L. | Papachlimitzou, Alexandra | Bolam, Thi | Warford, Lee | Hetherington, Stuart J. | Silva, Joana F. | McCully, Sophy R. | Losada, Sara | Maes, Thomas | Ellis, Jim | Law, Robin J.
The North-East Atlantic porbeagle (Lamna nasus) population has declined dramatically over the last few decades and is currently classified as ‘Critically Endangered’. As long-lived, apex predators, they may be vulnerable to bioaccumulation of contaminants. In this study organohalogen compounds and trace elements were analysed in 12 specimens caught as incidental bycatch in commercial gillnet fisheries in the Celtic Sea in 2011. Levels of organohalogen contaminants were low or undetectable (summed CB and BDE concentrations 0.04–0.85mgkg−1wet weight). A notably high Cd concentration (7.2mgkg−1wet weight) was observed in one mature male, whereas the range observed in the other samples was much lower (0.04–0.26mgkg−1wet weight). Hg and Pb concentrations were detected only in single animals, at 0.34 and 0.08mgkg−1wet weight, respectively. These contaminant levels were low in comparison to other published studies for shark species.
Показать больше [+] Меньше [-]Cryptosporidium and Giardia in tropical recreational marine waters contaminated with domestic sewage: Estimation of bathing-associated disease risks Полный текст
2014
Betancourt, Walter Q. | Duarte, Diana C. | Vásquez, Rosa C. | Gurian, Patrick L.
Sewage is a major contributor to pollution problems involving human pathogens in tropical coastal areas. This study investigated the occurrence of intestinal protozoan parasites (Giardia and Cryptosporidium) in tropical recreational marine waters contaminated with sewage. The potential risks of Cryptosporidium and Giardia infection from recreational water exposure were estimated from the levels of viable (oo) cysts (DIC+, DAPI+, PI−) found in near-shore swimming areas using an exponential dose response model. A Monte Carlo uncertainty analysis was performed in order to determine the probability distribution of risks. Microbial indicators of recreational water quality (enterococci, Clostridium perfringens) and genetic markers of sewage pollution (human-specific Bacteroidales marker [HF183] and Clostridium coccoides) were simultaneously evaluated in order to estimate the extent of water quality deterioration associated with human wastes. The study revealed the potential risk of parasite infections via primary contact with tropical marine waters contaminated with sewage; higher risk estimates for Giardia than for Cryptosporidium were found. Mean risks estimated by Monte Carlo were below the U.S. EPA upper bound on recreational risk of 0.036 for cryptosporidiosis and giardiasis for both children and adults. However, 95th percentile estimates for giardiasis for children exceeded the 0.036 level. Environmental surveillance of microbial pathogens is crucial in order to control and eradicate the effects that increasing anthropogenic impacts have on marine ecosystems and human health.
Показать больше [+] Меньше [-]Water solubility of metals in coarse PM and PM2.5 in typical urban environment in Hong Kong Полный текст
2014
Jiang, Sabrina Y.N. | Yang, Fenhuan | Chan, Ka Lok | Ning, Zhi
An investigation of abundance and solubility of metals in size–segregated particulate matter (PM) was conducted at a typical urban site during the winter between late 2011 and early 2012 in Kowloon Tong, Hong Kong. The samples were extracted by both strong acid and water, and fourteen elements including Al, Ca, Cd, Cr, Co, Cu, Fe, Pb, Mg, Mn, Mo, Ni, V, and Zn were analyzed using Inductively Coupled Plasma Optical Emission Spectrometry (ICP–OES) and Inductively Coupled Plasma Mass Spectrometry (ICP–MS). The metals in PM showed distinctly different profiles of their distribution between coarse particles (2.5μm<dp<10μm) and PM2.5 (dp<2.5μm). The upper continental crustal enrichment factors (CEFs) of the measured metals for two particle size fractions showed that CEFs for nine of fourteen metals in PM2.5 were higher than 10 while Cd, Pb, Zn, Mn and Cu were far above 100; whereas for coarse particles, the CEFs of most elements were lower than 10, except for Cd being higher than 100. Water and acid extractable fractions of coarse PM and PM2.5 were analyzed and compared to investigate the transition metals solubility. The water extractable fraction was found to be present mainly in the fine particles, whereas more of the coarse fraction mass remained as insoluble fraction. The results from this study demonstrated large variation of water solubility of metals in urban aerosols in different size fractions and highlighted solubility as an important metric for considering the relation between metals and adverse health effects in epidemiological and toxicological studies.
Показать больше [+] Меньше [-]Airborne molds and mycotoxins in Serpula lacrymans–damaged homes Полный текст
2014
Pottier, Didier | André, Véronique | Rioult, Jean–Philippe | Bourreau, Alain | Duhamel, Chantal | Bouchart, Valerie Kientz | Richard, Estelle | Guibert, Mathieu | Verite, Philippe | Garon, David
For some years, the degradation of homes by the dry rot fungus Serpula lacrymans increased. This study described, for the first time, the fungal contamination in homes located in Low–Normandy (France) and damaged by Serpula lacrymans. Wood–decaying fungi, airborne molds, fungal species growing on building materials were investigated by cultural and molecular methods. Mycotoxins in the air were quantified by HPLC–MS/MS and the mutagenicity of fungal aerosols was also evaluated using the Ames test. The results showed that Serpula lacrymans was detected in the air for one third of homes with sometimes the co–occurrence of other ligninolytic basidiomycetes species like Donkioporia expansa. Various molds in the air and on materials (117 and 103 species, respectively) were also identified indicating the complexity of indoor mycoflora. Certain recurrent species like Aspergillus versicolor and Penicillium fellutanum were observed both on building materials and in the air. The presence of cellulolytic molds in fungal aerosols and on building materials could be used as an indicator of home degradation. Airborne culturable fungal levels were measured up to 5.8x105 Colony Forming Units (CFU) per cubic meter of the air (CFU/m3) depending on the home. Fungal concentrations also depended on the type of collector (filter or liquid) and were significantly correlated with the median of particles between 2–15μm in size. Two mycotoxins (alternariol and/or ochratoxin A) were observed in 4 homes but no mutagenic activity was found.
Показать больше [+] Меньше [-]Sulfur dioxide exposure and environmental justice: a multi–scale and source–specific perspective Полный текст
2014
Zou, Bin | Peng, Fen | Wan, Neng | Wilson, JGaines | Xiong, Ying
Recent studies examining racial and ethnic inequities in exposure to urban air pollution have led to advances in understanding the nature and extent of overall concentration exposures by pollutant, demarcated by disadvantaged groups. However, the stability of inequities at various spatial units and the exposure by air pollution sources are often neglected. In this case study from the Dallas–Fort Worth (Texas, USA) area, we used Geographic Information Systems (GIS) and an air dispersion model to estimate environmental justice impacts at different spatial scales (i.e., zip code, census tract, block group) and by source (i.e., industrial pollution sources, vehicle pollution sources, industry and vehicle pollution sources combined). Using whites as a reference, blacks and other races were more likely to be exposed to higher sulfur dioxide (SO2) concentrations although the Odds Ratio (OR) varied substantially by pollution source type [e.g., industrial pollution source based: (OR=1.80; 95% CI (Confidence Interval): 1.79–1.80) vs. vehicle pollution source based: (OR=2.70; 95% CI: 2.68–2.71)] and varied less between spatial scales [for vehicle pollution sources, (OR=2.70; 95% CI: 2.68–2.71) at the census tract level but was (OR=2.54; 95% CI: 2.53–2.55) at the block group scale]. Similar to the pattern of racial inequities, people with less education (i.e., less than 12 years of education) and low income (i.e., per capital income below $20 000) were more likely to be exposed to higher SO2 concentrations, and those ORs also varied greatly with the pollution sources and slightly with spatial scales. It is concluded that the type of pollution source plays an important role in SO2 pollution exposure inequity assessment, while spatial scale variations have limited influence. Future studies should incorporate source–specific exposure assessments when conducting studies on environmental justice.
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