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Distribution of cadmium, mercury, and lead in different body parts of Baltic herring (Clupea harengus) and perch (Perca fluviatilis): Implications for environmental status assessments Full text
2014
Boalt, Elin | Miller, Aroha | Dahlgren, Henrik
For heavy metals, quality standards indicating good environmental status are designed to evaluate concentrations in the whole fish body, whereas monitoring of metals is often conducted using muscle or liver tissue. As most metals accumulate at different rates in different parts of fish, data should be adjusted to reflect whole fish body concentrations; however, this requires knowledge on distribution of metal concentrations within fish. Here, concentrations of cadmium, mercury, and lead were analyzed in the liver, muscle and whole fish of herring and perch to create conversion factors for transformation of heavy metal concentrations between these tissues. Species-specific accumulation of metals between muscle, liver, and whole fish were observed. Relationships between different tissues were used to recalculate data from monitoring programs in the Baltic Sea region. Based on whole fish concentrations, environmental status for cadmium and mercury in herring improved compared to assessments based on muscle or liver concentrations alone.
Show more [+] Less [-]Detoxification of hazardous dust with marine sediment Full text
2014
Wei, Yu-Ling | Lin, Chang-Yuan | Wang, H Paul
Hazardous electric arc furnace dust containing dioxins/furans and heavy metals is blended with harbor sediment, fired at 950–1100°C to prepare lightweight aggregates. Dust addition can lower the sintering temperature by about 100°C, as compared to a typical industrial process. After firing at 950°C and 1050°C, more than 99.85% of dioxins/furans originally present in the dust have been removed and/or destructed in the mix containing a dust/sediment ratio of 50:100. The heavy metals leached from all fired mixes are far below Taiwan EPA legal limits. The particle density of the lightweight aggregates always decreases with increasing firing temperature. Greater addition of the dust results in a considerably lower particle density (mostly <2.0gcm−3) fired at 1050°C and 1100°C. However, firing at temperatures lower than 1050°C produces no successful bloating, leading to a denser particle density (>2.0gcm−3) that is typical of bricks.
Show more [+] Less [-]Using principal component analysis and fuzzy c–means clustering for the assessment of air quality monitoring Full text
2014
Dogruparmak, Senay Cetin | Keskin, Gulsen Aydin | Yaman, Selin | Alkan, Atakan
Determining whether a reduction can be made in the total number of monitoring stations within the Air Quality Monitoring Network is very important since in case of necessity, the devices at one group of stations having similar air pollution characteristics can be transferred to another zone. This would significantly decrease the capital investment and operational cost. Therefore, the objective of this study was grouping the monitoring stations that share similar air pollution characteristics by using the methods of principal component analysis (PCA) and fuzzy c– means (FCM). In addition, this study also enables determining the emission sources, evaluating the performances of the methods and examining the zone in terms of pollution. In the classification of monitoring stations, different groups were formed depending on both the method of analysis and the type of pollutants. As a result of PCA, 5 and 3 classes have been determined for SO2 and PM10, respectively. This shows that the number of monitoring stations can be decreased. When reduced classes were analyzed, it was observed that a clear distinction cannot be made considering the affected source type. During the implementation of the FCM method, in order to facilitate comparison with the PCA, the monitoring stations were classified into 5 and 3 groups for SO2 and PM10, respectively. When the results were analyzed, it was seen that the uncertainty in PCA was reduced. When the two methods are compared, FCM was found to provide more significant results than PCA. The evaluation in terms of pollution, the results of the study showed that PM10 exceeded the limit values at all the monitoring stations, and SO2 exceeded the limit values at only 3 of the 22 stations.
Show more [+] Less [-]An approach to detecting species diversity of microfaunas in colonization surveys for marine bioassessment based on rarefaction curves Full text
2014
Xu, Guangjian | Zhong, Xiaoxiao | Wang, Yangfan | Xu, Henglong
The objective of this study was to measure α-, β- and γ-diversity of microfaunas with different ages in colonization surveys using rarefaction-modeling methods. A dataset was complied based on a microperiphyton survey in coastal waters of the Yellow Sea, near Qingdao. The analyses showed that: (1) there was a strong residual influence of sampling effort on β- and γ-diversity after rarefaction, especially for the young communities; (2) the rarefaction curves were well fitted to the Michaelis–Menten equation, and allow modeling and removing the residual influence of sampling effort on β- and γ-diversity; and (3) the estimated values of α-, β- and γ-diversity of a community based on the rarefaction-modeling method were independent of the influence of sampling effort. The results suggest that this approach may be used as a feasible tool to detect α-, β- and γ-diversity without the influence of sampling effort in microfauna colonization surveys for marine bioassessment.
Show more [+] Less [-]Occurrence and fate of triclosan and triclocarban in a subtropical river and its estuary Full text
2014
Lv, Min | Sun, Qian | Xu, Haili | Lin, Lifeng | Chen, Meng | Yu, Chang-Ping
The occurrence of triclosan (TCS) and triclocarban (TCC) in a subtropical river (Jiulong River) and its estuary was investigated for two years. TCS and TCC were ubiquitously detected in the Jiulong River and its estuary. The levels of TCS and TCC ranged from less than the method detection limit to 64ng/L and from 0.05 to 14.1ng/L in the river, respectively. The levels of TCS and TCC in the estuary ranged from 2.56 to 27.25ng/L and 0.38 to 5.76ng/L, respectively. Temporal and spatial variations of TCS and TCC in the Jiulong River and its estuary were observed during the investigation. The weather conditions did not show significant correlations with TCS and TCC, whereas several water quality parameters showed high correlations with TCS and TCC. The microcosm studies showed that both direct photolysis and biodegradation contributed to TCS removal, whereas indirect photolysis was important for TCC removal in the surface water.
Show more [+] Less [-]Analysis of total column ozone in Peninsular Malaysia retrieved from SCIAMACHY Full text
2014
Tan, Kok Chooi | Lim, Hwee San | Mat Jafri, Mohd Zubir
Due to lack of observational studies on greenhouse gases in Malaysia, most studies in this field were carried out based on ground station data. These studies did not utilize satellite data from the equatorial area. Satellite remote sensing is one of the most effective approaches for greenhouse gas distribution monitoring on a global scale. As such, satellite remote sensing exhibits a very high spatial and temporal resolution. Variations of ozone concentrations in Peninsular Malaysia were observed and investigated by means of data retrieved from the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY). The aim of this study was to determine the monthly and seasonal ozone concentrations in Peninsular Malaysia from January 2003 to December 2009. We utilized total column ozone at level 2 of the WFMD version 1.0. A spatial resolution value of 1°×1.25° was used. Analysis indicated that the five selected sites exhibited strong seasonal atmospheric ozone concentration variations. These variations resulted from the significant differences between the northeast monsoon (NEM) and the southwest monsoon (SWM). As the NEM prevails, cold air breaks out from Siberia and spreads to the equatorial region in the form of northeasterly cold surge winds. These winds manifest in low–level anticyclones over Southeast Asia. Inversely, the air masses from the southwest contribute to long–range air pollution. During SWM, the transport of atmospheric ozone by wind is associated with biomass burning in Sumatra, Indonesia. HYSPLIT was also utilized to identify the air pollutant transport between NEM and SWM toward Peninsular Malaysia. Comparisons were made between the ozone data from five sites in 2009. Data were retrieved from SCIAMACHY and the Atmospheric Infrared Sounder (AIRS). The relative difference average of the ozone data measured by SCIAMACHY and AIRS was approximately 6%.
Show more [+] Less [-]The traffic linked urban ambient air superfine and ultrafine PM1 mass concentration, contents of pro–oxidant chemicals, and their seasonal drifts in Lucknow, India Full text
2014
Verma, Mukesh Kumar | Singh Chauhan, Lalit Kumar | Sultana, Sarwat | Kumar, Sushil
The anthropogenic PM2.5 in ambient air is implicated in the increased health risks and morbidities of urban subjects. However in the literature, there is a limited information on mass concentrations and size segregated chemical profile of ultrafine and superfine PM1 fractions of traffic linked urban ambient air. The size, and the adsorbed chemicals, and response to seasonal change in this submicron range of particles have seldom been studied so far. We have looked into these aspects in urban ambient air of Lucknow Uttar Pradesh India. A 10–stage MOUDI cascade impactor sampled the superfine (PM0.56, PM0.32, PM0.18) and ultrafine particles (PM0.1, PM0.056) distributed in traffic linked ambient air. We studied their morphology, mass concentrations, the adsorbed metal contents and organic chemical moieties using TEM, gravimetric analyses, AAS, and FTIR spectroscopy. A change in their contents and profile with season was also examined. Results revealed spherical and fractal shapes of PM0.1, 50nm–2μm size range of PM0.56 fractions, and 10–100nm size range of constituent spherules. Gravimetric analyses disclosed mass concentrations and multifold increases in their levels in winter. Cr, Cd, Ni, Pb and transition element Cu, Fe were found to be present in the studied particles. The presence of aliphatic and aromatic hydrocarbons with hydroxyl, carbonyl, and ketone groups were also found and displayed changes in their levels with season. Presence of organonitrate compounds indicated the role of submicron and nanosize particulates in secondary aerosol formation also. Results are important for epidemiological studies and public policy on superfine and ultrafine particulate matter in urban ambient air for identification of toxicity risk or health hazard, air quality monitoring and regulation.
Show more [+] Less [-]Quantifying and modelling the carbon sequestration capacity of seagrass meadows – A critical assessment Full text
2014
Macreadie, P.I. | Baird, M.E. | Trevathan-Tackett, S.M. | Larkum, A.W.D. | Ralph, P.J.
Seagrasses are among the planet’s most effective natural ecosystems for sequestering (capturing and storing) carbon (C); but if degraded, they could leak stored C into the atmosphere and accelerate global warming. Quantifying and modelling the C sequestration capacity is therefore critical for successfully managing seagrass ecosystems to maintain their substantial abatement potential. At present, there is no mechanism to support carbon financing linked to seagrass. For seagrasses to be recognised by the IPCC and the voluntary C market, standard stock assessment methodologies and inventories of seagrass C stocks are required. Developing accurate C budgets for seagrass meadows is indeed complex; we discuss these complexities, and, in addition, we review techniques and methodologies that will aid development of C budgets. We also consider a simple process-based data assimilation model for predicting how seagrasses will respond to future change, accompanied by a practical list of research priorities.
Show more [+] Less [-]The application of histo-cytopathological biomarkers in the mud crab Scylla serrata (Forskal) to assess heavy metal toxicity in Pulicat Lake, Chennai Full text
2014
Arockia Vasanthi, Lourduraj | Muruganandam, Azhagu | Revathi, Peranandam | Baskar, Balakrishnan | Jayapriyan, Kodhilmozhian | Baburajendran, Ramaswamy | Munuswamy, Natesan
The concentrations of heavy metals and their associated structural deformities in the gills, muscles and hepatopancreas of Scylla serrata from Pulicat Lake were determined and compared with crabs live along Kovalam coast. The concentrations of metals were high in the hepatopancreas and gills of crab from Pulicat Lake, whereas, low in crab from the Kovalam coast. Data were visualized using a principal component analysis (PCA). Significant differences were found for all variables at the plot scale; however, the overall variation was relatively low for muscle tissues in both stations. The structural deformities observed in the gills, hepatopancreas and muscle was due to metal toxicity, and the degree of damage was correlated with the elevated metal concentration. The results showed significant metal accumulation and histo-cytological lesions in the crabs from Pulicat Lake. The results suggest that these biomarkers are useful for assessing the impact of metal pollution in the coastal environments.
Show more [+] Less [-]Seasonal distribution of ultraphytoplankton and heterotrophic prokaryotes in relation to abiotic variables on the north coast of Sfax after restoration Full text
2014
Rekik, Amira | Denis, Michel | Dugenne, Mathilde | Barani, Aude | Maalej, Sami | Ayadi, Habib
The Taparura project was set up to restore the north Sfax coast (Tunisia) by shutting down the northern phosphate plant responsible for chronic pollution and uncontrolled phosphogypsum dumping. The restoration effect on coastal ultraphytoplankton (<10μm) and heterotrophic prokaryotes was investigated using conventional flow cytometry over four successive seasons during 2009–2010. Cell concentrations were generally higher than values reported for the open sea, both in the western and eastern Mediterranean basins. One striking point was that chl a concentration on the north Sfax coast was unchanged after restoration but was still one order of magnitude higher than in the Gulf of Gabès. Restoration of pH, following the shutdown of the phosphate processing plants on the north coast, appeared to reach normal levels for seawater during the study, whereas seawater acidification persisted on the south coast where plants are still in operation. The largest ultraphytoplankton biomass was from an unknown cell group, whose identity and role needs to be established.
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