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Environmental fate and ecological risks of nonylphenols and bisphenol A in the Cape D’Aguilar Marine Reserve, Hong Kong Texto completo
2015
Xu, Elvis G.B. | Morton, Brian | Lee, Joseph H.W. | Leung, Kenneth M.Y.
Nonylphenols (NPs) and bisphenol A (BPA) are the most common endocrine disruptors detected in the coastal waters of Hong Kong. The Cape D’Aguilar Marine Reserve (CAMR), the only marine reserve in Hong Kong is close to urbanized areas, thus the resident marine organisms are inevitably influenced by partially treated wastewater from adjacent sewage treatment plants (STPs). Elevated levels of NPs and BPA were detected in all seawater, sediment and biota samples collected from the CAMR. Estrogenic activities of seawater from the CAMR, and sludge and sewage from a nearby STP were assessed using yeast estrogen screen assay. We found aromatase, estrogen receptor and vitellogenin genes in the marine medaka fish Oryzias melastigma were significantly up-regulated after exposure to the reserve’s seawater. According to a tissue-residue-based probabilistic risk assessment, the marine species living in the CAMR are having 35% and 21% of chance to be at risk due to exposure to NPs and BPA, respectively.
Mostrar más [+] Menos [-]A three-dimensional water quality model to evaluate the environmental capacity of nitrogen and phosphorus in Jiaozhou Bay, China Texto completo
2015
Li, Keqiang | Zhang, Li | Li, Yan | Zhang, Longjun | Wang, Xiulin
Jiaozhou Bay has recently suffered from serious problems with pollution and eutrophication. Thus, land-based pollutant load must be reduced through a national control program. In this study, we developed a 3D water quality model to determine the environmental capacity of nitrogen and phosphorus in Jiaozhou Bay. A 3D hydrodynamic model (the estuarine, coastal, and ocean modeling system with sediments) was coupled with a water quality model, which was adapted from the dynamic model of nitrogen and phosphorus for a mesocosm near Jiaozhou Bay. The water quality model is divided into seven components: dissolved inorganic nitrogen, phosphate, phytoplankton, zooplankton, detritus, dissolved organic nitrogen, and dissolved organic phosphorus. Furthermore, it was calibrated based on data collected from Jiaozhou Bay in 2003. The proposed model effectively reproduced the spatiotemporal variability in nutrient concentration, thus suggesting that a reasonable numerical representation of the prototype system must be developed for further evaluation of environmental capacity.
Mostrar más [+] Menos [-]Application of Stabilized Nanoparticles for In Situ Remediation of Metal-Contaminated Soil and Groundwater: a Critical Review Texto completo
2015
Liu, Wen | Tian, Shuting | Zhao, Xiao | Xie, Wenbo | Gong, Yanyan | Zhao, Dongye
Remediation of soil and groundwater contaminated with toxic metals has been a major environmental challenge for decades. Yet, cost-effective and sustainable in situ remediation technologies remain lacking. Over the last 15 years or so, an innovative in situ remediation strategy has shown promising by means of stabilized nanoparticles. Stabilized nanoparticles are prepared using novel stabilizers that facilitate the deliverability and transport of nanoparticles in the subsurface. This study reviews synthesis and characterization of some model stabilized nanoparticles and their application for remediation of metal-contaminated soil and water. Fate and transport of these stabilized nanoparticles in groundwater and soil are also examined. Lastly, this review identifies the key knowledge gaps such as lack of field data pertaining to the long-term effectiveness of the immobilized metals and impacts of the delivered nanoparticles on the biogeochemical conditions in the subsurface. The information may facilitate further development of this promising remediation technology.
Mostrar más [+] Menos [-]Residents’ perception of air quality, pollution sources, and air pollution control in Nanchang, China Texto completo
2015
Liao, Xiong | Tu, Hong | Maddock, Jay E. | Fan, Si | Lan, Guilin | Wu, Yanyan | Yuan, Zhao Kang | Lu, Yuanan
To assess the public's understanding of the main sources of air pollution in Nanchang and factors influencing their perceptions of Nanchang's air quality status, a face–to–face survey data was collected at the provincial children's hospital and four kindergarten classes in Nanchang. A total of 989 parents with children between the ages of 2 to 10 years old participated in the survey. Among which 69% of respondents believed that the current air quality was worse than three years ago. This study reveals that parents who were under 40 years old of age with higher education level and international travel experience, had higher level awareness of air pollution. Men tend to have lower knowledge of air pollution as compared to women. The top three selected sources of air pollution were motor vehicles (78.5%), waste burning (56.3%) and industrial facilities (53.7%). In addition, 79.8% of respondents believed that the government did not spend enough on environmental protection and 96.8% suggested to increase government funding to improve air quality. The majority of respondents (>90%) strongly urges the Nanchang government to prioritize environmental protection. The findings from this study suggest the need for the government to improve the awareness of the main sources of air pollution, especially to residents of rural areas with lower levels of education, to more effectively and efficiently control air pollution in Nanchang.
Mostrar más [+] Menos [-]Paleo-Perspectives on Potential Future Changes in the Oxidative Capacity of the Atmosphere Due to Climate Change and Anthropogenic Emissions Texto completo
2015
Alexander, Becky | Mickley, Loretta J.
The oxidizing capacity of the atmosphere, defined as the global mean tropospheric abundance of the hydroxyl radical (OH·), strongly influences air pollution by controlling the lifetimes of gaseous pollutants and the production of particulate matter. Predicting future changes in OH· due to anthropogenic emissions and climate change is of interest to air quality managers, but it is difficult because of multiple competing effects. Models of atmospheric chemistry suggest that these competing effects buffer significant change in OH· in the past and in the near future. However, proxy-based observations for past changes in OH· and other oxidants over the preindustrial-industrial and glacial-interglacial time scales suggest much larger changes than models estimate. Model sensitivity studies show that variability in past and future OH· is highly sensitive to relative emissions of reactive nitrogen and carbon, water vapor, lightning, and stratospheric ozone, implying that one or more of these variables is highly sensitive to climate.
Mostrar más [+] Menos [-]δ13C and δ15N in deep-living fishes and shrimps after the Deepwater Horizon oil spill, Gulf of Mexico Texto completo
2015
Quintana-Rizzo, Ester | Torres, Joseph J. | Ross, Steve W. | Romero, Isabel | Watson, Kathleen | Goddard, Ethan | Hollander, David
The blowout of the Deepwater Horizon (DWH) drill-rig produced a surface oil layer, dispersed micro-droplets throughout the water column, and sub-surface plumes. We measured stable carbon and nitrogen isotopes in mesopelagic fishes and shrimps in the vicinity of DWH collected prior to, six weeks after, and one year after the oil spill (2007, 2010 and 2011). In 2010, the year of the oil spill, a small but significant depletion of δ13C was found in two mesopelagic fishes (Gonostoma elongatum and Chauliodus sloani) and one shrimp (Systellaspis debilis); a significant δ15N enrichment was identified in the same shrimp and in three fish species (G. elongatum, Ceratoscopelus warmingii, and Lepidophanes guentheri). The δ15N change did not suggest a change of trophic level, but did indicate a change in diet. The data suggest that carbon from the Deepwater Horizon oil spill was incorporated into the mesopelagic food web of the Gulf of Mexico.
Mostrar más [+] Menos [-]Impact of harbour, industry and sewage on the phosphorus geochemistry of a subtropical estuary in Brazil Texto completo
2015
Berbel, Glaucia B.B. | Favaro, Deborah I.T. | Braga, Elisabete S.
The distribution of different forms of phosphorus in surface sediment from 17 sites were investigated by SEDEX method. The sites were divided into three sectors: Santos Channel (SC – influenced by harbour, fertilizers plants and phosphogypsum mountains), São Vicente Channel (SVC– domestic waste) and Santos Bay (SB – sewage outfall). The average percentage of each P fraction of the surface sediments in this region followed the sequence P–Fe (38%)>Porg (27%)>Pexch (13%)>Detrital – P (12%)>Auth – P (10%). Ptotal varied from 3.57 to 74.11μmolg−1 in both seasons. In SVC, Pexch ranged from 13% to 27% and Porg varied from 12% to 56%. These high percentages of Pexch/Ptotal (greater than 20%) may be related to low oxygen resulting from oxygen consumed by intensive organic matter decomposition as well as the salty water that leads to cation and anion flocculation. Also, the possibility of an influence related to the industrial source of Pexch is not ruled out. No significant seasonal differences were found among sites, except for sewage outfall, with changing in the grain size and hence, the P geochemistry. During the summer in the sewage outfall station, Porg represented 37% of Ptotal, which decreased to 13% in the winter. These results suggest that high percentages of organic phosphorus cannot be attributed only to autochthonous and allochthonous organic matter, but also to detergents and/or domestic waste. In contrast, spatial differences among sectors were observed, with the highest values of each fraction associated with sites near industrial and domestic waste activities.
Mostrar más [+] Menos [-]Arsenic Contamination in Soil and Sediment in India: Sources, Effects, and Remediation Texto completo
2015
Shrivastava, Anamika | Ghosh, Devanita | Dash, Ayusman | Bose, Suatapa
Arsenic contamination is turning out to be a major problem these days with its area coverage and the number of people affected directly or indirectly. Now, the level of the contaminant has spread over the soil and sediments from groundwater and other natural sources. Arsenic poisoning in groundwater events is familiar to the world, but the consequences of soil contamination are still unrevealed to the community, specially the people of contaminated counties. Arsenic is a serious instantaneous concern for the people and other life forms regarding the poisoning through crops and vegetables. Many remediation technologies that mainly include physical, chemical, and a few biological methods have been evolved with time to check its effects. The physical and chemical methods for this purpose are often inefficient and/or very expensive, mainly limited to application in aqueous systems, and produce toxic sludge, which again becomes a matter of concern. But bioremediation relies on the fact that biological organisms have the ability to degrade, detoxify, and even accumulate harmful chemicals and offers attractive perspectives for biomonitoring (via biosensors), treatment of wastewater, and the recycling of polluted soils.
Mostrar más [+] Menos [-]Heavy metal contamination and ecological risk assessment in the surface sediments of the coastal area surrounding the industrial complex of Gabes city, Gulf of Gabes, SE Tunisia Texto completo
2015
El Zrelli, Radhouan | Courjault-Radé, Pierre | Rabaoui, Lotfi | Castet, Sylvie | Michel, Sylvain | Bejaoui, Nejla
In the present study, the concentrations of 6 trace metals (Hg, Cd, Cu, Pb, Cr and Zn) were assessed in the surface sediments of the central coastal area of Gabes Gulf to determine their contamination status, source, spatial distribution and ecological risks. The ranking of metal contents was found to be Zn>Cd>Cr>Pb>Cu>Hg. Correlation analysis indicated that Cd and Zn derived mainly from the Tunisian Chemical Group phosphogypsum. The other pollutants may originate from other industrial wastes. Metallic contamination was detected in the south of chemical complex, especially in the inter-harbor zone, where the ecological risk of surface sediments is the highest, implying potential negative impacts of industrial pollutants. The spatial distribution of pollutants seems to be due to the effect of harbor installations and coastal currents. The metallic pollution status of surface sediments of Gabes Gulf is obvious, very worrying and requires rapid intervention.
Mostrar más [+] Menos [-]Adaptability of free-floating green tide algae in the Yellow Sea to variable temperature and light intensity Texto completo
2015
Cui, Jianjun | Zhang, Jianheng | Huo, Yuanzi | Zhou, Lingjie | Wu, Qing | Chen, Liping | Yu, Kefeng | He, Peimin
In this study, the influence of temperature and light intensity on the growth of seedlings and adults of four species of green tide algae (Ulva prolifera, Ulva compressa, Ulva flexuosa and Ulva linza) from the Yellow Sea was evaluated. The results indicated that the specific growth rate (SGR) of seedlings was much higher than that of adults for the four species. The adaptability of U. prolifera is much wider: Adult daily SGRs were the highest among the four species at 15–20°C with 10–600μmol·m−2·s−1 and 25–30°C with 200–600μmol·m−2·s−1. SGRs were 1.5–3.5 times greater than the other three species at 15–25°C with 200–600μmol·m−2·s−1. These results indicate that U. prolifera has better tolerance to high temperature and light intensity than the other three species, which may in part explain why only U. prolifera undergoes large-scale outbreaks and floats to the Qingdao coast while the other three species decline and disappear at the early stage of blooming.
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