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891.
This case study was conducted to evaluate the use of reclaimed lake sediment as a growth media for vegetable production and to estimate whether accumulation of micronutrients and heavy metals in the vegetables would impact human nutrition or health, respectively. Five plant species, bean (Phaseolus vulgaris L.), broccoli (Brassica oleracea L.), carrot (Daucus carota L.), pepper (Capsicum annum L.), and tomato (Lycopersicon esculentum L.), were grown in pots containing either reclaimed sediment from the Illinois River or a reference soil. Edible and vegetative tissues from the plants were analyzed for 19 elements, including As, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se, and Zn. Tomato and pepper grown in sediment showed significantly greater biomass and yield as compared to plants from the reference soil. Elemental analysis of the tissues revealed that Zn and Mo were the only elements that were significantly greater in sediment-grown plants on a consistent basis. While significant, Zn concentrations were no more than 3-fold higher than those in plants from the reference soil. The same trend was observed for Mo, except for bean tissues, which showed a 10-fold greater concentration in sediment-grown plants. The projected dietary intake of Cu, Mo, and Zn from consumption of sediment-grown vegetable tissues was significantly higher than for soil-grown plants, although the contribution to the recommended dietary allowances (RDAs) for these elements was substantial only for Mo. Intake of sediment-grown beans would have provided 500% of the dietary Mo RDA. While this is below the lowest observable adverse effect level (LOAEL) value for this element, there is no evidence to indicate that there would be a nutritional or therapeutic benefit from the consumption of bean containing this level of Mo. The dietary exposures to Cd and Pb would have been below the pertinent limits for all age and gender groups with the exception of the cumulative dietary Cd exposure to the 1-3 year age group. The results from this study suggest that this reclaimed sediment can be utilized for the production of vegetables intended for human consumption. The results from this case study also suggest that sediment material with similar physicochemical characteristics and elemental concentrations that fall within the pertinent regulatory guidelines should also be a suitable and safe medium for vegetable production.  相似文献   
892.
The potential of soil microorganisms to enhance the retention of (137)Cs and (85)Sr in organic systems was assessed in a series of experiments. A biologically active, 'mineral-free', organic material, produced under laboratory conditions from leaves, was used as the uptake matrix in all experiments to minimise potential interference from competing clay minerals. Biological uptake and release were differentiated from abiotic processes by comparing the sorption of radionuclides in sterilised organic material with sterile material inoculated with soil extracts or single fungal strains. Our results show conclusively that living components of soil systems are of primary importance in the uptake of radionuclides in organic material. The presence of soil microorganisms significantly enhanced the retention of Cs in organic systems and approximately 70% of the Cs spike was strongly (irreversibly) bound (remained non-extractable) in the presence of microorganisms compared to only approximately 10% in abiotic systems. Sorption of (85)Sr was not significantly influenced by the presence of soil microorganisms. A non-linear temperature response was observed for the retention in biotic systems with increased uptake at between 10 and 30 degrees C and lower retention at temperatures above or below the optimum range. The optimum temperatures for biological uptake were between 15 and 20 degrees C for Cs, and 25 and 30 degrees C for Sr. Our results indicate that single strains of soil and saprotrophic fungi make an important contribution to the sorption of Cs and Sr in organic systems, but can only account for part of the strong, irreversible binding observed in biotic systems. Single strains of soil fungi increased the amount of non-extractable (137)Cs (by approximately 30%) and (85)Sr (by approximately 20%) in the organic systems as compared to abiotic systems, but the major fraction of (137)Cs and (85)Sr sorbed in systems inoculated with saprotrophic fungi remained extractable.  相似文献   
893.
The fish faunas of the outer basin (Nornalup Inlet), inner basin (Walpole Inlet) and saline region of the main tributary (Frankland River) of the permanently open Nornalup-Walpole Estuary on the southern coast of Western Australia, were sampled bimonthly for a year using seine and gill nets, and also during a further two months by the former method. Although the Nornalup-Walpole Estuary is permanently open, the catches of fish in its shallows were dominated (98.4%) by estuarine-spawning species, thereby paralleling the situation in the nearby and seasonally closed Wilson Inlet. In contrast, larger representatives of several marine species were present in appreciable numbers in the offshore, deeper waters of both of these estuaries. The delayed recruitment of marine species into these estuaries apparently reflects the distance that the juveniles of these species have to travel from the areas where they are believed predominantly to spawn. The larger representatives of marine species made a greater contribution to the fish faunas of the offshore, deeper waters in the Nornalup-Walpole Estuary than in Wilson Inlet (64.5 vs 36.9%) and, unlike the situation in the latter estuary, they included five species of elasmobranchs, two of which (Mustelus antarcticus and Myliobatis australis) were relatively abundant. Classification and ordination of the combined data for both estuaries demonstrated that the composition of the fish fauna in the offshore, deeper waters of the outer basin of the Nornalup-Walpole Estuary was particularly distinct, with some marine species being restricted to these waters. This is presumably related both to the presence of a permanently open entrance channel and the relatively deep waters found in Nornalup Inlet, which allow the ready exchange of water between the sea and estuary and the maintenance of high salinities in the deeper regions of the outer basin for much of the year. The fish faunas in Walpole Inlet and the tributaries of both the Nornalup-Walpole Estuary and Wilson Inlet were more similar to each other than they were to those in the more seawards end of either estuary. This similarity reflects the apparent preference of certain teleosts, such as the estuarine species Acanthopagrus butcheri and the marine species Mugil cephalus and Aldrichetta forsteri for reduced salinities and/or features associated with riverine environments.  相似文献   
894.
Air samples were collected from 4 field sites in Europe: 2 sites from the UK, Hazelrigg (semi-rural) and Manchester (urban); 1 site from Ireland: Mace Head (rural); and 1 site from Norway: Kjeller (rural). Additionally, air samples were taken from indoor locations in Troms?, Norway. Air samples were collected using high-volume air samplers employing sampling modules containing glass-fibre filters (GFFs, particle phase), and glass columns with a polyurethane foam (PUF)-XAD-2-PUF sandwich (gaseous phase). Typical outdoor air volumes required for the determination of per- and polyfluorinated alkyl substances (PFAS) ranged from 500-1800 m3. GFFs and PUF-XAD columns were analysed separately to obtain information on phase partitioning. All air samples were analysed for volatile, neutral PFAS, with selected GFF samples halved for analysis of both neutral and airborne particle-bound ionic PFAS. Volatile PFAS were extracted from air samples by cold-column immersion with ethyl acetate, and were analysed by gas chromatography-mass spectrometry in the positive chemical ionisation mode (GC-PCI-MS). Ionic PFAS were extracted from GFFs by sonication in methanol, and were analysed by liquid chromatography-time-of-flight-mass spectrometry (LC-TOF-MS) using electrospray ionisation in the negative ion mode (ESI-). Perfluorooctanoate (PFOA) was often the predominant analyte found in the particulate phase at concentrations ranging from 1-818 pg m(-3), and 8:2 fluorotelomer alcohol (FTOH) and 6:2 FTOH were the prevailing analytes found in the gas phase, at 5-243 pg m(-3) and 5-189 pg m(-3), respectively. These three PFAS were ubiquitous in air samples. Many other PFAS, both neutral and ionic, were also present, and levels of individual analytes were in the 1-125 pg m(-3) range. Levels of some PFAS exceeded those of traditional persistent organic pollutants (POPs). In this study, the presence of 12:2 FTOH and fluorotelomer olefins (FTolefins), and ionic PFAS other than perfluorooctane sulfonate (PFOS) and PFOA, are reported in air samples for the first time. Concentrations of neutral PFAS were several orders of magnitude higher in indoor air than outdoor air, making homes a likely important diffuse source of PFAS to the atmosphere. Our repeated findings of non-volatile ionic PFAS in air samples raises the possibility that they might directly undergo significant atmospheric transport on particles away from source regions, and more atmospheric measurements of ionic PFAS are strongly recommended.  相似文献   
895.
896.
897.
Environmental Science and Pollution Research - Oil spills are a significant stressor to coastal and maritime environments worldwide. The growth responses of Batis maritima and Avicennia germinans...  相似文献   
898.
Environmental Science and Pollution Research - In this study, six supervised classification algorithms were compared. The algorithms were based on cluster analysis, distance, deep learning, and...  相似文献   
899.
A central tenet of landscape ecology is that mobile species depend on complementary habitats, which are insufficient in isolation, but combine to support animals through the full annual cycle. However, incorporating the dynamic needs of mobile species into conservation strategies remains a challenge, particularly in the context of climate adaptation planning. For cold-water fishes, it is widely assumed that maximum temperatures are limiting and that summer data alone can predict refugia and population persistence. We tested these assumptions in populations of redband rainbow trout (Oncorhynchus mykiss newberrii) in an arid basin, where the dominance of hot, hyperproductive water in summer emulates threats of climate change predicted for cold-water fish in other basins. We used telemetry to reveal seasonal patterns of movement and habitat use. Then, we compared contributions of hot and cool water to growth with empirical indicators of diet and condition (gut contents, weight–length ratios, electric phase angle, and stable isotope signatures) and a bioenergetics model. During summer, trout occurred only in cool tributaries or springs (<20 °C) and avoided Upper Klamath Lake (>25 °C). During spring and fall, ≥65% of trout migrated to the lake (5–50 km) to forage. Spring and fall growth (mean [SD] 0.58% per day [0.80%] and 0.34 per day [0.55%], respectively) compensated for a net loss of energy in cool summer refuges (–0.56% per day [0.55%]). In winter, ≥90% of trout returned to tributaries (25–150 km) to spawn. Thus, although perennially cool tributaries supported thermal refuge and spawning, foraging opportunities in the seasonally hot lake ultimately fueled these behaviors. Current approaches to climate adaptation would prioritize the tributaries for conservation but would devalue critical foraging habitat because the lake is unsuitable and unoccupied during summer. Our results empirically demonstrate that warm water can fuel cold-water fisheries and challenge the common practice of identifying refugia based only on summer conditions.  相似文献   
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