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Results 201 - 250 of 593
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Stone Micheal - - 2008
Erosion experiments were conducted in an annular flume to determine the effect of bed age and shear stress on the particle morphology (fractal dimensions D, D(1), and D(k)) of eroded cohesive river sediment. Sediment beds were deposited under low shear and left to consolidate for one, two and seven days. ...
Butler Richard J - - 2008
Previous attempts to determine palaeoenvironmental preferences in dinosaurs have generally been qualitative assessments based upon data from restricted geographical areas. Here, we use a global database of Cretaceous herbivorous dinosaurs to identify significant associations between clades and broad palaeoenvironmental categories ('terrestrial', 'coastal', 'marine'). Nodosaurid ankylosaurs and hadrosaurids show significant positive ...
Praveena S M - - 2008
Spatial variations in estuarine intertidal sediment have been often related to such environmental variables as salinity, sediment types, heavy metals and base cations. However, there have been few attempts to investigate the difference condition between high and low tides relationships and to predict their likely responses in an estuarine environment. ...
Rantavaara A - - 2008
(90)Sr and (137)Cs in domestic foodstuffs and water have been analysed in Finland since the early 1960s, and (134)Cs since 1986. Using data on radionuclide deposition levels, agricultural production, and the processing and consumption of foodstuffs, the average intake and radiation dose from the ingestion of these radionuclides have been ...
Choi Min-Seok - - 2008
The concentrations of naturally occurring radioisotopes ((232)Th, (228)Th, (230)Th, (228)Ra, (226)Ra, and (40)K) in typical Korean foods were evaluated. The daily intakes of these radioisotopes were calculated by comparing concentrations in typical Korean foods and the daily consumption rates of these foods. Daily intakes were as follows: (232)Th, 0.00-0.23; (228)Th, ...
Prichard H M - - 2008
The Coisley Hill roundabout, a typical urban source for PGE in stream sediments, has anomalously high values of up to 408 ppb Pt, 444 ppb Pd and 113 ppb Rh in road dust, up to 416 ppb Pt and 278 ppb Pd in gulley sediment and up to 606 ppb ...
Van Geen A - - 2008
Whereas serious health consequences of widespread consumption of groundwater elevated in As have been documented in several South Asian countries, the mechanisms responsible for As mobilization in reducing aquifers remain poorly understood. We document here a previously unrecognized and consistent relationship between dissolved As concentrations in reducing groundwater and the ...
Lin Chitsan - - 2009
Sediment samples were analyzed for di-(2-ethylhexyl) phthalate (DEHP), an organic endocrine disruptor, in Houjing River in southern Taiwan. The average DEHP concentration at 10 sampling locations, spanning from upper, middle, and lower segments of the stream, was calculated at 3.81+/-6.36mgkg(-1)drywt. Highest concentration was recorded at the Jhongsing Bridge (20.22mgkg(-1)drywt.) near ...
Spadaro D A - - 2008
The amphipod Melita plumulosa is commonly used to assess the toxicity of contaminated sediments. Seven-day-old M. plumulosa are <1 mm in size, and during 10-day tests in sandy sediments with low nutritional value, starvation can cause >50% mortality. In sediment toxicity tests, therefore, it can be difficult to determine if ...
Misdaq M A - - 2008
U, Th, Rn, and Rn concentrations were measured in thirteen bottled mineral water samples from Morocco, France, and Italy widely consumed by the European population living in the city of Marrakech (Morocco) by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). K contents were also evaluated ...
Franić Zdenko - - 2009
The long-term behaviour of (137)Cs activity concentrations in air and fallout has been studied in the city of Zagreb for the post-Chernobyl period (1986-2006) as a part of an extended monitoring program of radioactive contamination of human environment in Croatia. Annual mean (137)Cs activity concentrations in air and annual total ...
Franić Zdenko - - 2008
Long-term investigations of radiocaesium activity concentrations in beef in the Republic of Croatia are presented. The radiocaesium levels in beef decreased exponentially and the effective ecological half-life of 137Cs was estimated to be 0.57+/-0.06 years for 1986-1990 period and 5.21+/-0.27 years for the 1991-2005 period. For 1986-1990 period, the effective ...
Assunta Meli Maria - - 2008
The aim of this study was to determine background levels of natural radionuclides such as uranium isotopes, (210)Pb, (210)Po, and (40)K in mussels Mytilus galloprovincialis, collected in the central Adriatic Sea along the Marche region as a mechanism to establish a biomonitoring model for human radiation exposure resulting from ingestion ...
Hadad Kamal - - 2008
Hundred and sixteen water resources including springs, wells, rivers and lakes in Ardabil province, northwest of Iran, were sampled and analyzed. The analysis included chemical analyses, (222)Rn and (226)Ra levels as well as total Uranium contents. (222)Rn levels were determined only for hot springs. The concentrations of Radium and Uranium ...
Liu Ruiping - - 2008
The explosion at a plant of the Jilin Petrochemical Corporation on 13 November, 2005, and the spill of an estimated 100 t of toxic substances (nitrobenzene as the main component) into the Songhua River received worldwide attention. This study has focused on the adsorption behavior of nitrobenzene that spilled onto ...
Tiegs Scott D - - 2008
Although species commonly modify habitats and thereby influence ecosystem structure and function, the factors governing the ecological importance of these modifications are not well understood. Pacific salmon have repeatedly been shown to positively influence the abundance of benthic biota by annually transferring large quantities of nutrients from marine systems to ...
Nasreddine L - - 2008
Since the primary factor contributing to the internal effective dose in the human organism is contaminated food, the control of radionuclides in food represents the most important means of protection. This study was conducted to determine the levels of the dietary exposure of the Lebanese population to gamma-emitting radioisotopes. The ...
Prado G R - - 2008
The Southwest region of the Bahia state in Brazil hosts the largest uranium reserve of the country (100 kton in uranium, only), plus the cities of Caetité, Lagoa Real and Igaporã. In this work, aim was at the investigation of uranium burdens on residents of these cities by using teeth ...
Yodnarasri Supaporn - - 2008
The sediment parameters and nematode assemblages in the intertidal zone of the Hichirippu shallow lagoon, Hokkaido, Japan, were investigated. The objectives of this study were to observe the seasonal variation in the nematodes in the sediment, and to investigate the relationships between the nematodes and environmental factors. Samples were collected ...
Fenoglio Stefano - - 2008
The Euthyplociidae are a tropical and subtropical Ephemeropteran group. The aim of this study was to augment knowledge on some aspects of the biology and ecology of Euthyplocia hecuba (Hagen, 1861) nymphs. Mayflies were collected in the Rio El Padre, located on the Caribbean slope of Honduras. Diet, microhabitat preference ...
Thorsson Maria H - - 2008
Settling organic matter (OM) is the major food source for heterotrophic benthic fauna. The high sorption affinity of many contaminants for OM implies that OM can influence both the distribution and bioavailability of contaminants. Here, we experimentally examine the role of settling OM of various nutritional qualities on the bioaccumulation ...
Ramírez-Alvarez Nancy - - 2007
We measured stable isotope ratios (delta(13)C and delta(15)N) of particulate organic matter (POM) sources and benthic organic matter compartments as well as sediment C to N ratios from the coastal area of the southern end of the Southern California Bight (SCB). We used the isotopic values to evaluate the relative ...
Dyson Kirstie E - - 2007
Despite the complexity of natural systems, heterogeneity caused by the fragmentation of habitats has seldom been considered when investigating ecosystem processes. Empirical approaches that have included the influence of heterogeneity tend to be biased towards terrestrial habitats; yet marine systems offer opportunities by virtue of their relative ease of manipulation, ...
Wyatt Shane A - - 2008
In May 2004, two groundwater wells in Dinwiddie County, Virginia were found to have natural uranium levels either at or above the EPA recommended limit of 30 microg/l. As a result, a stop drinking water advisory was issued until a water treatment system could be installed to remove the uranium. ...
de la Ossa Carretero J A - - 2008
Sewage discharge is a common source of pollution in coastal marine waters. Several municipal treatment plants dump treated water in medium to fine sand Spisula subtruncata communities. This bivalve is generally considered a major food source for demersal fishes, and it is important as a dominant species in structuring the ...
Dousová Barbora - - 2007
Arsenic (As) occurs in atmospheric deposition both in soluble and insoluble forms, mainly bound to fine aerosol particles (less than 2.5 microm). Interception deposition (i.e. fog, dew and ice accretion) represents a specific type of atmospheric deposition, which has been much more contaminated with As than bulk deposition. This study ...
Zhao Yu - - 2007
The critical load concept has become widely accepted as an important theoretical basis for establishing effective acid deposition control strategies. In the critical load calculations, the influence of variation in base cation (BC) deposition, which plays an important role in mitigating acidification, was seldom considered. In this manner, high uncertainty ...
Turhan Seref - - 2007
Eleven different wild-growing edible mushroom species collected from various regions of Turkey were analysed for their content of 137Cs, 40K, 226Ra and 232Th using a high-resolution gamma-ray spectrometry. Specific activities of 226Ra and 232Th were generally below detection limits. The specific activities of 137Cs and 40K ranged from 2.4+/-0.3 to ...
Sousa Ana - - 2007
Organotin (OT) compounds have been used as biocide agents in antifouling paints since the mid 1960s and are now ubiquitous in the marine environment. Due to their high toxicity to non-target species they were banned from antifouling paints in the European Union in 2003 (2002/62/EC directive). The aim of the ...
Banas D - - 2008
Expansion of aquaculture has increased concern over its environmental impact. The composition of effluents from intensive aquaculture is well documented, but few data on extensive aquaculture are available. During 12 draining operations, 523 water samples were collected downstream from six extensively-managed fishponds in northeastern France. Study ponds had surface areas ...
Jackson Matthew G - - 2007
Substantial quantities of terrigenous sediments are known to enter the mantle at subduction zones, but little is known about their fate in the mantle. Subducted sediment may be entrained in buoyantly upwelling plumes and returned to the Earth's surface at hotspots, but the proportion of recycled sediment in the mantle ...
Fathivand A A - - 2007
Measures to protect the public following an accidental release of radionuclides to the environment will depend on the circumstances including the extent of the potential hazards. The projected level of risk is an important precondition in emergency planning. The levels can be expressed in terms of concentration levels in the ...
Fernandes Milena - - 2007
Farming of wild tuna in coastal areas is a relatively new aquaculture industry and little is known about the magnitude of nutrient discharges to the environment. In this work we present a preliminary model of nitrogen loads from southern bluefin tuna (Thunnus maccoyii) aquaculture in lower Spencer Gulf, South Australia. ...
Colosio F - - 2007
Beach nourishment (i.e. the addition of sediments transported from other source locations) is increasingly used to counteract erosion of coastal areas. We tested whether sediment descriptors (grain size structure and organic content) and macrobenthic assemblages (species composition and abundance) differed among replicated shores previously exposed to nourishment alone (N), nourishment ...
Ainslie Michael A - - 2007
Multipath ocean reverberation originating from the seabed in shallow isovelocity water, with particular attention to its information content in the cylindrical spreading and mode stripping regions, is considered. The reverberation is evaluated using Weston's flux integral method, both analytically with various simplifying approximations and numerically with all but one of ...
Cakal Arslan O - - 2007
Nonylphenol (NP) and octylphenol (OP), both of which are biodegradation products of alkylphenols, are widely used in industrial applications and in some domestic products. These chemicals are found widely in surface water and aquatic sediments. We have carried out a comparative embryotoxicity analysis of the effects of increasing concentrations of ...
Panatto Donatella - - 2007
In the years 2001-2004 the (137)Cs activity was investigated in a total of 336 samples of different varieties of honey harvested in the Liguria Region of Northern Italy. Our purpose was to define (a) residual radioactive contamination following the Chernobyl accident and (137)Cs long-term decline, (b) correlation between (137)Cs activity ...
Stock Naomi L - - 2007
Perfluorosulfonates (PFSAs) and perfluorocarboxylates (PFCAs) have been hypothesized to reach remote locations such as the Canadian Arctic either indirectly as volatile precursor chemicals that undergo atmospheric transport and subsequent degradation, or directly via oceanic and atmospheric transport of the PFSAs and PFCAs themselves. Water, sediment, and air samples were collected ...
Ruberu Shiyamalie R - - 2007
Groundwater wells from across the State of California were sampled and analyzed for Pb and Po. The separation method involved Fe(OH)3 precipitation from a 5-L groundwater sample followed by electrodeposition of Po on a nickel disk. The resulting solution was passed through an ion-exchange resin column for the isolation of ...
Bennett Sean J - - 2007
Sediments impounded within flood control reservoirs are potentially important archives of environmental and geomorphic processes occurring within drainage basins. The concentrations of select sediment-associated trace elements were assessed within the impoundment of Grenada Lake, a relatively large flood control reservoir in Mississippi with a history of contaminant bioaccumulation in fish. ...
Törnqvist Torbjörn E - - 2007
Turner et al. (Reports, 20 October 2006, p. 449) measured sedimentation from Hurricanes Katrina and Rita in coastal Louisiana and inferred that storm deposition overwhelms direct Mississippi River sediment input. However, their annualized hurricane deposition rate is overestimated, whereas riverine deposition is underestimated by at least an order of magnitude. ...
Schoellhamer David H - - 2007
Water-quality managers desire information on the temporal and spatial variability of contaminant concentrations and the magnitudes of watershed and bed-sediment loads in San Francisco Bay. To help provide this information, the Regional Monitoring Program for Trace Substances in the San Francisco Estuary (RMP) takes advantage of the association of many ...
Xiang Cai-Hong - - 2007
Polybrominated diphenyl ethers (PBDEs) were analyzed in three invertebrate species, five fish species with different living and feeding habits, and surface sediments collected from the Pearl River Estuary, South China. The concentrations of 10 PBDE congeners (BDEs 28, 47, 66, 99, 100, 85, 154, 153, 138, and 183) ranged from ...
Diener Michael D - - 2007
Fullerenes could potentially play a valuable role in radioimmunotherapy by more stably encapsulating radionuclides, especially where conventional chelation chemistry is inadequate due to the physical and/or chemical properties of the radionuclide. One of the therapeutically useful radionuclides that requires improved containment in vivo is 212Pb (tau1/2 = 10.6 h), the ...
Ramaswamy V - - 2007
The macro-tidal Gulf of Kachchh, covering nearly 7000 km(2), is located about 150 km south of the Indus River mouth. In spite of semi-arid climate and lack of major rivers flowing into it, the Gulf is highly turbid with suspended sediment concentrations (SSC) during October-November 2002 ranging between 0.5 and ...
Gaskell Paul N - - 2007
Aquatic ecological risk assessment is primarily focused on aqueous exposure, but many hydrophobic contaminants bind to particulate material and accumulate in sediments. The risk posed by such contaminants is partially dependent on the importance of dietary exposure. Here, we describe the bioaccumulation of a highly hydrophobic compound (dioctadecyl-dimethyl ammonium chloride ...
Bouchet Vincent M P - - 2007
Sediment cores were collected from April to August 2004 on tidal mudflats of the macrotidal Marennes-Oléron Bay (SW France), famous for the cultivation of Pacific oysters (Crassostrea gigas). The response of living (stained) benthic foraminifera to short-term biogeochemical disturbances in the sediment and overlying water, which may be involved in ...
Murakami Michio - - 2007
Individual particles containing Cr and/or Pb and other major components were identified in road dust from a heavily used road (hereinafter 'heavy traffic road dust'), road dust from a residential area and soakaway sediment by electron probe microanalyser to locate their sources and carrier particles. Individual particles containing high levels ...
Inwood Sarah E - - 2007
We investigated controls on stream sediment denitrification in nine headwater streams in the Kalamazoo River Watershed, Michigan, USA. Factors influencing denitrification were determined by using experimental assays based on the chloramphenicol-amended acetylene inhibition technique. Using a coring technique, we found that sediment denitrification was highest in the top 5 cm ...
Karlsson Stefan - - 2007
The acid-leachable amount and pore water concentration of As, Bi and Ga in sediment cores from four remote lakes in a south to north transect in Sweden were used to recapitulate the pollution history of the elements. The diagenetic impact on the element distribution was elucidated from their solid/solution partition ...
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