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1.
Trace elements in coal   总被引:1,自引:0,他引:1  
Trace elements can have profound adverse effects on the health of people burning coal in homes or living near coal deposits, coal mines, and coal-burning power plants. Trace elements such as arsenic emitted from coal-burning power plants in Europe and Asia have been shown to cause severe health problems. Perhaps the most widespread health problems are caused by domestic coal combustion in developing countries where millions of people suffer from fluorosis and thousands from arsenism. Better knowledge of coal quality characteristics may help to reduce some of these health problems. For example, information on concentrations and distributions of potentially toxic elements in coal may help delineate areas of a coal deposit to be avoided. Information on the modes of occurrence of these elements and the textural relations of the minerals in coal may help to predict the behavior of the potentially toxic trace metals during coal cleaning, combustion, weathering, and leaching.  相似文献   

2.
Four selenium (Se) nonaccumulator plant species, including a forage grass species, Tall Fescue (Festuca arundinacea Schreb.), a forage legume species, Alfalfa (Medicago sativa L.), a wetland species, Rush (Juncus tenuis Wild.), and a dry-land alkaline soil species, Saltgrass (Distichlis spicata L.), were grown in soil contaminated by agricultural drainage sediment having elevated levels of Se and sulfur (S). The above-ground plant tissues were consecutively harvested five times and examined for Se and S accumulation. Plant tissue Se concentrations ranged from 23.0 mg kg-1 to 8.3 mg kg-1. Tissue S concentrations ranged from 3239 mg kg-1 to 7034 mg kg-1. Both tissue Se and S concentrations were significantly different between harvests, species, and species/harvest interactions. Total Se accumulation by the plant biomass harvested ranged from 0.3 to 1.3 mg per soil column and total S accumulations ranged from 87.5 to 321.1 mg per soil column. The reduction in the percentage of total soil Se after 24 weeks growth of the plant species ranged from 12.0% in the Tall Fescue planting to 17.3% in the Rush planting. Over 90% of the soil Se losses were unidentified losses and leaching of Se was prevented. The accumulations of Se and S in the plant biomass were very small compared with the total soil Se and S losses, but substantial amounts of total soil Se (12.0 to 15.0%) and S (28.0 to 50.9%) inventories were dissipated by the growing and harvesting of the plants. The soil S concentration was several hundred times higher than the soil Se concentration, but Se accumulation by the plants and Se dissipation from the soil were not impaired by the high level of soil sulfur. For natural grassland habitat restoration, such as at the Kesterson Wildlife Refuge in the Central Valley of California, or for restoration of large-scale Se contaminated agricultural lands, Se nonaccumulator plant species are favorable candidates, because the possibility of introducing Se toxicity into the food chain can be minimized.  相似文献   

3.
Significantly more information about trace element status can be obtained by investigating concentrations in blood cells instead of only evaluating the concentrations in plasma. This can be explained by the fact that essential trace elements such as zinc, copper, chromium and selenium take part in a variety of enzymatic processes on a molecular cellular level. Ignoring these important biochemical roles, trace element concentrations determined in whole blood or plasma very often lead to conclusions contrary to the actual intracellular concentration. Especially in metabolic diseases like diabetes mellitus, conclusions drawn from trace element concentrations in blood cells usually offer more valuable clinical information about the metabolic state than trace element concentrations in plasma or whole blood. In the present investigation copper and zinc concentrations were increased in all blood fractions of diabetic patients (IDDM). In insulin-dependent diabetic children significantly higher values of zinc in erythrocytes were also found, and they were higher in patients with poor metabolic control (HbA1c>9%). When different blood fractions in diabetic patients (NIDDM) were compared with a control group, chromium was significantly increased in plasma and polymorphonuclear cells. Patients with IDDM had pronounced decreased selenium concentrations in erythrocytes as compared to controls.  相似文献   

4.
This study evaluated Co, Cr, Mn, Ni, Se, Sn and V status in the soils of the PHA, as well as the vegetables produced on these soils. We also determined the agronomic sources of these elements to the soils in the PHA. Farmyard manures applied as fertilizer amendments to the soils in the PHA were found to be the major agronomic sources of the metal and metalloid elements. These elements were however, retained in significantly higher concentrations in the soils compared to the concentrations found in the edible portions of the vegetable crops collected. This, in turn, resulted in these vegetables being poor sources of several of the essential mineral nutrients. It is therefore suggested that: (1) a wider variety of crops are assessed for their mineral nutrient status, (2) to find ways to increase the availability of these mineral nutrients and (3), that the possibilities of micronutrient and trace element deficiencies be assessed in the communities surrounding the PHA.  相似文献   

5.
6.
Abstract

The status of 13 trace elements’ (both essential and toxic) was investigated in individual parts of the winter wheat plant(Triticum aestivum) taken during its whole cultivation period. The study includes the determination of total concentrations, portions soluble in 0.02 mol L?1 Tris-HCI buffer solution (pH = 7.5), and the fractionation of soluble species of elements by SEC and ICP/MS. Ligands of trace elements from a low-molecular weight SEC fraction were isolated by affinity chromatography and characterised by MALDI/MS analyses and by amino acids composition. Inhomogeneous accumulation of trace elements was found in the analysed plant tissues. The concentrations of elements are also affected by the maturity of the plants. The distribution of the soluble species of the elements between chromatographic fractions exhibited some regularity in all the samples. Substantial amounts of trace elements are located in a low-molecular weight fraction (< 2 kDa). Only chromatograms of Zn (grain) and Cu (all samples) contain significant medium-molecular and high-molecular weight fractions. Compounds isolated from the low-molecular weight fractions are rich in cystein and dicarboxylic amino acids or their amides. MALDI/MS spectra of these compounds isolated from shoots, straw and grain confirmed the presence of the phytochelatin PC5.  相似文献   

7.
Question: How important are habitat configuration, quality, history and anthropic disturbance in determining nemoral plant species richness and distribution of fragmented forest patches in a Mediterranean region? Location: Agricultural landscape north of Rome, Italy. Methods: Sixty‐nine woodland patches, identified through a stratified random sampling, were sampled for nemoral plant species. The homogeneity of woodlands was tested through a hierarchical classification of the floristic data and a Mann‐Whitney test of dependent and independent variables. The importance of habitat configuration (area, isolation, shape), quality (soil properties, forest structure, anthropic disturbance) and history (age of woodland) in determining species richness was estimated through a Poisson regression model. Presence‐absence of each species was analysed by logistic regression. Differences among plant life‐trait types (life span, dispersal mode, habitat preference) were analysed by comparing their median β‐values through ANOVA models. Results: Through hierarchical classification, two woodland types were identified that differed in species composition, habitat quality and spatial configuration. Poisson regression showed that habitat configuration and history influenced species richness. Multiple logistic regression resulted in significant fits for 88 species/variable combinations: 38 are habitat quality variables, 25 are habitat configuration variables, and 13 are anthropic factors. Dispersal strategies varied significantly with respect to area, isolation and age, while generalist and specialist species differed according to age of the woodland. Conclusion: Our results show that habitat history and configuration are the key factors determining species richness of woodland. Together with habitat configuration, habitat quality (mainly soil acidity) appeared to influence species composition.  相似文献   

8.
Biominerals and metals of intertidal corals of two species (Heliofungia actiniformis, Quoy and Gaimard;Galaxea fascicularis, Linnaeus), collected from the Iriomote Island of Ryukyu, were examined with an inductively coupled plasma atomic emission spectrometer (ICP-AES). Twelve elements were detectable in the coralline skeletons dissected radially along the growth axis. The relative content (RC) of Hg periodically fluctuated and was minimum at the hollow sites of the coralline slab ofHeliofungia sp., corresponding to the cyclic growth. There were two types of elements: constant elements and variable elements along the growth axis. RCs of Ca, Mg, A1, Si, and P were nearly constant. RCs of Fe, Mn, Cu, and Ba were variable, but not as regularly changed as Hg. There were positive mass correlations of Hg to Mn, Cu and Zn, but not to Ba and Fe. In contrast, these relationships were not prominent and were likely degraded by aging in the skeleton ofGalaxea sp., suggesting a different mode from that of theHeliofungia sp.  相似文献   

9.
This study investigated the dissolved trace metal contamination levels of Zn, Sr, B, Al, Ba, Fe, Mn, Li, V, Be, Cd, Cr, Cu, Mo, Ni, Se, and Pb in 23 surface waters of the Yellow River Delta (YRD) in China. Coefficients of variation with 66–260% reflected large spatial variations of concentrations of metals. Compared to drinking water guidelines established by the World Health Organization and the U.S. Environmental Protection Agency, the primary trace metal pollution components (Al, B, V, and Zn) were above drinking water standard levels by 82.6%, 47.8%, 52.2%, and 52.2%, respectively. Preliminary risk assessments were determined via the Hazard Quotient (HQ) to evaluate the human health risk of these metals. HQingestion of V indicated potential deleterious health effects for residents. Hierarchical cluster results revealed that clusters 1, 2, and 3 were primarily affected by pollution from industrial and domestic activities, natural and agriculture activities, and oil fields, respectively. Principal component analysis results indicated Fe, Mn, Al, and Ba were controlled by natural sources, whereas anthropogenic activities led to high pollution levels of Al, B, V, Zn, and Sr.  相似文献   

10.
Due to rapid industrialization and urbanization, human activities like industrial and agricultural production, transportation, aggravate heavy metal pollution in soil and continue to endanger vegetables and human health. In this study, three contaminated areas affected by heavy metal pollution in Guangdong Province were investigated in terms of Cu, Zn, Pb, and Cd concentrations in soil and vegetables. Further analyses of the contamination status and potential risks to the health of residents consuming these vegetables were conducted. Results showed the following average heavy metal concentrations in vegetables and soil: Shaoguan > Guangzhou > Dongguan, indicating that mining has caused massive soil-heavy metal pollution. The heavy metal concentrations and Bioconcentration factors (BCFs) showed the following trend: leaf-vegetables > fruit-vegetables > root-vegetables, and those of vegetable type were as follows: Cd > Zn > Cu > Pb. The Nemero pollution index (PI) of all research region soils and hazard index (HI) exceeded 1. Hence, more attention should be paid to the potential for adverse health effects caused by the consumption of vegetables produced in these sites . Thus, effective measures are encouraged, with a focus on children due to their vulnerability to these heavy metals.  相似文献   

11.
Contamination of freshwater bodies and consequently freshwater fish with toxic heavy metals is a serious environmental issue. The trophic transfer of potentially toxic heavy metals in the human food chains, especially in fish has important implications for human health. The present research study was designed to assess the concentrations of the heavy metals Cr, Ni, Cd, and Pb in the water, sediments, and different freshwater fish species of River Kabul, Pakistan. The heavy metals were quantified in the samples with Atomic Absorption Spectrophotometer. Heavy metal contamination in fish muscles was characterized in terms of metal pollution index and biota-sediments accumulation factor, while human health risk was assessed through calculation of estimated weekly intake. The average concentrations of Cr, Ni, Cd, and Pb in muscle samples of the analyzed fish species at different sampling sites of the river ranged from 12.3 to 33.0, 33.2 to 109.2, 0.98 to 1.5, and 13.9 to 29.6 mg kg?1 wet weight, respectively. Based on the current study data, consumption of the analyzed freshwater fish species from River Kabul was generally safe in terms of potential risk from Cd and Pb but the observed Ni accumulation may pose a potential health risk to regular/excessive fish consumers.  相似文献   

12.
选择乐安河—鄱阳湖湿地典型植物群落,采用重要值方法评价各样点植物群落特征并筛选出典型优势植物,通过室内理化测试分析不同生境中优势植物植株及其根区土壤中重金属Cu、Pb、Cd的含量;采用生物富集系数(BCF)方法评价不同优势植物对重金属Cu、Pb、Cd的富集特性。结果表明:研究区湿地植物以草本为主,在各样点共发现124种物种,包括蕨类植物2科2属2种,种子植物40科97属122种,并从中筛选出羊蹄、红蓼、鼠曲草、紫云英、苎麻等5种富集能力较强的优势植物;植物根区土壤中的Cu、Cd含量均超过土壤环境质量三级标准,而且Cu、Cd的最高含量分别为824.03、5.03 mg·kg-1;不同优势植物对Cu、Pb、Cd等3种重金属元素中的1种或2种表现出较强的富集能力,其中优势物种红蓼对Cu具有较强的富集能力,含Cu量最高为148.80 mg·kg-1,另一种优势物种鼠曲草对三种元素的生物富集系数均较高,且对Cd的最高富集含量为15.17 mg·kg-1,对Cd的生物富集系数最高值为19.14,高于其他植物10倍以上,鼠曲草对重金属Cd具有富集植物的基本特征,且对Cu和Cd具有共富集特征并具有较高的耐性,紫云英、羊蹄等对Cd的富集能力也较强。上述5种优势植物种群对鄱阳湖湿地Cu、Pb、Cd等重金属污染物的生态修复具有一定参考价值,可作为鄱阳湖湿地重金属污染修复植物的选择对象。  相似文献   

13.
Levels of Mo, As, Se, Fe, Cu, Zn, Ni, and Pb were determined in a vegetable commonly consumed in Pakistan. Samples were collected from three different sites (Ratokala, Phularwan, and Mailowal) supplied with three different water sources. Mo and Pb in water and Mo and As in C. sativum were higher than the suggested standards at the international level. Lower bioconcentration factor and pollution load index were seen at Site-I than at other sites. A positive association was found between the rhizosphere metals and those of the vegetable at all three sites. Enrichment factor at three sites ranged from 0.28 to 10.39. The highest value of daily intake of metals was found for Fe (0.245 mg/kg/day) and of the health risk index for As (70.41) at the wastewater inundated site. It is inferred that uptake of Mo, As, Cu, Ni, and Pb through C. sativum represents a high health danger to the individuals using this vegetable.  相似文献   

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