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921.
This study examined the levels of seven heavy metals (namelyzinc, copper, cadmium, chromium, lead, manganese and iron) andtheir associations with magnetic properties in playground dustof Hong Kong. Results showed that the playground dust containedhigh concentrations of Zn (mean = 1883 g g-1), Cu(mean = 143 g g-1) and Cr (mean = 263 g g-1).Qualitative examination of dust samples under microscope indicated local traffic as one of the important pollutant sources. Magnetic measurements indicated that these anthropogenicpollutants mainly consisted of coarse-grained multidomain (MD) ferrimagnetic minerals. Superparamagnetic (SP), stable single domain (SSD) ferrimagnetic grains and non-ferrimagnetic mineralswere present in relatively small amounts. Significant correlations between heavy metals and various magnetic parametersindicated a strong affinity of heavy metals to magnetic minerals hence pointed out the potential of magnetic properties for simpleand rapid proxy indications of heavy metal pollution in playground dust.  相似文献   
922.
This study reported the test done on ash-sludge mixture foramendment of soil in pot experiments. Ash-sludge mixture ratiostudies revealed that 1:5 fly ash-sludge mixture and 1:10 bottom ash-sludge mixture were the optimum mixture ratio thatminimized toxic element and provided sufficient nutrients. Experiments indicated that ash-sludge mixtures is more suitablefor amendment of acid soil than neutral soil which can increasesoil pH and reduce available heavy metal toxicity. The maximumheavy metal adsorption occurred in a pH range of 4 to 6 for allsoil studied. The finding also revealed that fly ash applicationseemed more effective than bottom ash, due to its higher loadingrate and metal contents. Heavy metal toxicity was monitored usingseed germination test. Marigold and tomato seeds were the two crops selected for this test. Seed germination test result showsthat percentage of seed germination increased in pot experimentswith sludge only and ash-sludge mixtures. In addition, higherpercentages of seed germination were observed to vary with longer incubation time (1–8 weeks). After week 12 of the incubation period, percentage of seed germination began to decline, as a result of reduced soil pH and release of toxic heavy metals.  相似文献   
923.
The use of different moss species – Hylocomium splendens,Pleurozium schreberi, Eurhynchium angustirete, Sphagnum and Rhytidiadelphus – was tested for the investigation of atmosphericheavy metal deposition. Maps representing heavy metal depositionpattern in Lithuania are presented for Cd, Cr, Cu, Fe, Ni, Pb and V.The most suitable species for heavy metal deposition studies was Hylocomium splendens in which the concentrations of metalswere found to be up to 25% higher than in other species. Interspeciesand interelemental comparison was also performed. Several well definedlocal pollution sources were identified.  相似文献   
924.
The Niepoomice Forest is a large forestcomplex (110 km2) situated in southern Poland 10 to 30 kmto the east of the urban industrial Kraków agglomeration andsteelworks, which was built up on the outskirts of the city in1950. Due to prevailing westerly winds, the forest is affectedby pollutants emitted by both the steelworks and the city. Thelevel of heavy metal contamination in the Niepoomice Forestwas described using a sensitive bioindicator – the moss Pleurozium schreberi. Mean concentrations of metals in mosscollected in the Niepoomice Forest were Cd – 0.71, Cr – 2.4,Cu – 8.6, Fe – 673, Pb – 12.7, and Zn – 61 mg/kg.Concentrations of heavy metals in moss in the NiepoomiceForest decreased in time. As compared with the relatively cleanarea in north-eastern Poland (Puszcza Biaowieska), the concentration of Fe was 2–9 fold and Pb 4–6 fold higher in theNiepoomice Forest in 1975, while in 1998 4 fold and 2 fold,respectively. In both 1975 and 1998 the most polluted by heavymetals was the western part of the Niepoomice Forest (closestto the pollution sources) and the area along the roads insidethe forest complex.  相似文献   
925.
We provide an overview of research related to environmental effects of disposal of coal combustion residues (CCR) in sites in the United States. Our focus is on aspects of CCR that have the potential to negatively influence aquatic organisms and thehealth of aquatic ecosystems. We identify major issues of concern, as well as areas in need of further investigation.Intentional or accidental release of CCR into aquatic systemshas generally been associated with deleterious environmental effects. A large number of metals and trace elements are presentin CCR, some of which are rapidly accumulated to high concentrations by aquatic organisms. Moreover, a variety of biological responses have been observed in organisms following exposure to and accumulation of CCR-related contaminants. In some vertebrates and invertebrates, CCR exposure has led to numerous histopathological, behavioral, and physiological (reproductive, energetic, and endocrinological) effects. Fish kills and extirpation of some fish species have been associatedwith CCR release, as have indirect effects on survival and growth of aquatic animals mediated by changes in resource abundance or quality. Recovery of CCR-impacted sites can be extremely slow due to continued cycling of contaminants withinthe system, even in sites that only received CCR effluents forshort periods of time. The literature synthesis reveals important considerations for future investigations of CCR-impacted sites. Many studies have examined biological responses to CCR with respect to Se concentrations and accumulation because of teratogenic andreproductively toxic effects known to be associated with thiselement. However, the complex mixture of metals and traceelements characteristic of CCR suggests that biologicalassessments of many CCR-contaminated habitats should examine avariety of inorganic compounds in sediments, water, and tissuesbefore causation can be linked to individual CCR components. Most evaluations of effects of CCR in aquatic environments havefocused on lentic systems and the populations of animalsoccupying them. Much less is known about CCR effects in loticsystems, in which the contaminants may be transported downstream,diluted or concentrated in downstream areas, and accumulated bymore transient species. Although some research has examinedaccumulation and effects of contaminants on terrestrial and avianspecies that visit CCR-impacted aquatic sites, more extensiveresearch is also needed in this area. Effects in terrestrial orsemiaquatic species range from accumulation and maternal transferof elements to complete recruitment failure, suggesting that CCReffects need to be examined both within and outside of theaquatic habitats into which CCR is released. Requiring specialattention are waterfowl and amphibians that use CCR-contaminatedsites during specific seasons or life stages and are highlydependent on aquatic habitat quality during those periods.Whether accidentally discharged into natural aquatic systems or present in impoundments that attract wildlife, CCR appears topresent significant risks to aquatic and semiaquatic organisms. Effects may be as subtle as changes in physiology or as drasticas extirpation of entire populations. When examined as a whole,research on responses of aquatic organisms to CCR suggests thatreducing the use of disposal methods that include an aquaticslurry phase may alleviate some environmental risks associatedwith the waste products.  相似文献   
926.
Animal hair is a good biomonitoring tool for heavy metals assessment and reflects the content of heavy metals in the forage and soil. Heavy metals Fe, Mn, Co and Ni as well as toxic metals Cd and Pb were determined in goat, sheep and camel hair, forage and soil collected from four different environmental urban and rural regions. These regions are Aswan city farms, Allaqi desert pasture, Kalabsha farms and Halaiub desert pasture at far south of Egypt. The results reveal that sheep hair contains the highest levels of Fe and Mn (879 and 55 μg/g, respectively), camel hair contains the highest Pb, whereas for goat Cd and Ni were the highest. Heavy metal concentrations in the studied hair reflect the presence of these metals in the surrounding forage and soil and vary from one area to another, and give knowledge of pollution in the area. Correlation statistics analysis and cluster analysis show a good and significant value between metals in hair and plants.  相似文献   
927.
Seventeen fog events were sampled in Baton Rouge, Louisiana during 2002–2004 as part of characterizing wet deposition by fogwater in the heavily industrialized corridor along the Louisiana Gulf Coast in the United States. These samples were analyzed for chemical characteristics such as pH, conductivity, total organic and inorganic carbon, total metals and the principal ion concentrations. The dominant ionic species in all samples were NH4+, NO3, Cl and SO42−. The pH of the fogwater sampled had a mean value of 6.7 with two cases of acidic pH of 4.7. Rainwater and fogwater pH were similar in this region. The acidity of fogwater was a result of NO3 but partly offset by high NH4+. The measured gaseous SO2 accounted for a small percentage of the observed sulfate concentration, indicating additional gas-to-particle conversion of SO2 to sulfate in fogwater. The gaseous NOx accounted for most of the dissolved nitrate and nitrite concentration in fogwater. The high chloride concentration was attributable to the degradation of chlorinated organics in the atmosphere. The metal composition was traced directly to soil-derived aerosol precursors in the air. The major metals observed in fogwater were Na, K, Ca, Fe, Al, Mg and Zn. Of these Na, K, Ca and Mg were predominant with mean concentrations > 100 μM. Al, Fe and Zn were present in the samples, at mean concentrations < 100 μM. Small concentrations of Mn (7.8 μM), Cu (2 μM), Pb (0.07 μM) and As (0.32 μM) were also observed in the fogwaters, and these were shown to result from particulates (PM2.5) in the atmosphere. The contribution to both ions and metals from the marine sources in the Louisiana Gulf Coast was minimal. The concentrations of all principal ionic species and metals in fogwater were 1–2 orders of magnitude larger than in rainwater. Several linear alkane organic compounds were observed in the fogwater, representing the contributions from petroleum products at concentrations far exceeding their aqueous solubility. A pesticide (atrazine) was also observed in fogwater, representing the contribution from the agricultural activities nearby.  相似文献   
928.
The spill at `Los Frailes caused a large input of metals intothe riverine, estuarine and coastal ecosystems. Metal behaviourin natural waters can be studied both by performing fieldmeasurements, and by undertaking laboratory simulationexperiments. Here is described the behaviour of the heavymetals Zn, Cd, Pb and Cu in the Guadalquivir estuary usingincubation experiments and the results compared to thoseobtained during field assessments. If the toxic waste water hadbeen discharged untreated into the environment, it could haveraised the heavy metal concentrations in the estuary water tohigh values, such as 20.65 M for Zn and 40 × 10-3 M for Cd. These values are several times higher than thoseobtained in samples collected in the area during the monitoringof the early impact. The metals present a non-conservative behaviour, with a high loss to waters of low salinity values.  相似文献   
929.
One of India's major concerns is the increasing level of land pollution largely due to the uncontrolled disposal of industrialsolid and hazardous waste. With rapid industrialization, thegeneration of industrial solid and hazardous waste has increasedappreciably and the nature of waste generated has become complex.Their impacts on the ecological bodies are noticeable. The article describes the details of studies conducted using Toxicity Characteristics Leaching Procedure, to estimate the toxicity effects of the metals viz., chromium, zinc, manganese,iron, nickel, cobalt and copper by the Zero Headspace Extractorfor the sludges generated from effluent treatment plant of steeltube, wire and plating industries on environment constituentslike groundwater, surface water and land. Toxicity Characteristics Leaching Procedure determines the mobility of organic and inorganic analytes of liquid, solid or multiphase waste from hazardous solid wastes in the form of primary and secondary extracts. These extracts are mixed in equal volumeproportion and analyzed by Direct Reading 2000 spectrophotometer.The amount of heavy metals observed during the studies in theleachates were found and the results were compared with HazardousWaste categories as per Indian Standards, TCLP regulatory limitsgiven by United States Environment Protection Agency (USEPA) andGermany Leachate Quality Standards and it was observed that theywere on higher side, needing a proper preventive concept of sludge management including handling, treatment, recovery and disposal.  相似文献   
930.
Concentrations of heavy metals and major ions were measured in precipitation, snowpack, garden soils and vegetables from urban and rural sites in New Brunswick in Atlantic Canada. Atmospheric loading of mercury, lead, cadmium, arsenic, strontium, and vanadium need further assessment. Vanadium concentrations in precipitation, snowpack, soils and vegetables showed an urban influence. Vanadium concentrations in the snowpack ranged between <2.0 ppb at 50 kilometers from the city center to 31.4 ppb in the city. Concentrations of all heavy metals in urban soils were less than CCME remediation guidelines but selected metals exceeded the assessment benchmark non-regulatory guidelines. Major ions were consistently higher in event precipitation than the snowpack. The order of ion elution from the snowpack was NO3 > SO4 > NH4 > H > Mg > Cl > Na > K. Hydrogen ion equivalents were highest in the snowpack and precipitation from urban samples. Mean hydrogen ion concentrations ranged from 11 to 22 eq L-1 in the snowpack compared with 18 to 41 eq L-1 in event precipitation.  相似文献   
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