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51.
A total of 200 Jordanian children were classified into two groups: 100 Fe replete and 100 Fe deficient with ages ranging between 3.0 and 12.0 years (6.9 ± 2.7 years). All participants were chosen according to proper selection criteria followed by the sample collection: the samples were analyzed for hemoglobin and red blood cells; ferritin, an immunoassays-based instrument; and levels of Pb, Cu, and Zn. There were no significant differences between genders regarding Fe-deficiency (p = 0.57 and χ2 = 0.33), with a significant association of younger individuals (3.0–9.1 years) with Fe-deficiency (p < 0.05 and χ2 = 22.7).

In addition, there is a significant positive correlation between Fe-deficiency with blood levels of Pb, Cu, and Zn (p < 0.05), (r = 0.43, 0.35, and 0.42, respectively) as compared to control group, this findings supported, by comparing the levels of the examined metals in both groups, in individuals whom close to heavy metals source (highway traffic or oil gas station), and found that the mean of the heavy metals level in close Fe-deficient group higher than in close Fe-replete group.  相似文献   
52.
Penicillium chrysogenum was immobilized on silica to develop a simple and cost effective method for solid phase extraction of Cd(II) and determination using flame atomic absorption spectrometry (FAAS). The sorbent was characterized by Fourier transform infrared spectroscopy and packed into a column. The conditions for quantitative sorption and desorption of Cd(II) were optimized. The preconcentration factor was 100 while detection limit was 0.61 µg L?1 with a relative standard deviation of 1.0%. The method was applied for determination of Cd in herbal medicine and tap water.  相似文献   
53.
The hypotheses on the de novo syntheses of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo‐p‐dioxins (PCDDs), based on known literature, are presented. Polychlorinated benzenes and polychlorinated phenols are probably key intermediates.

In the present article, hypotheses that may account for the presence of polychlorinated dibenzofurans (PCDFs) and dibenzo‐p‐dioxins (PCDDs) in the effluents from municipal and industrial incinerators are put forward. These hypotheses are based on the previously surveyed literature (Ref. 203–206) and experimental results on laboratory scale and thermodynamic calculations are considered. The interconnections of various reaction steps are speculative and no technological information was added to account for conditions in real incinerators. Conclusion of the discussions on the related subject matter, presented in the Parts I‐IV (Ref. 203–206), are also described in this paper.  相似文献   
54.
An accurate, simple and cheap extraction and cleanup procedure for capillary GC analysis of organo‐chlorine insecticides (OCs) in vegetables (cabbage and carrots) at the ng/g level, and for soil at the μg/g level is presented. The cleanup is carried out on solid‐phase extraction (SPE) cartridges, filled with 500 mg silica, 1 g of deactivated Florisil (10% w/w water), and 100 mg of anhydrous sodium sulphate. Recoveries >90% are obtained. The cleanup of OCs in fatty samples on an HPLC LiChrosorb Si 100 column is evaluated for subsequent capillary GC analysis. Fractionation of OCs and Aroclor 1254 and 1260 on an HPLC Nucleosil 100 column appears to be satisfactory.  相似文献   
55.
Ambient air samples at ten sites in an iron and steel industrial complex were collected from June to December for analyzing polycyclic aromatic hydrocarbons (PAHs). Sixteen species of PAH components in air samples were identified. The results indicate that both gaseous phase and particle‐bound PAHs at the top of the cokemaking plants are unusually high. The profiles of particle‐bound PAHs indicate that the predominant species at the top of, the coke oven batteries are those of high molecular weight components. The major components of particle‐bound PAHs at sampling sites near the fenceline, however, include the medium molecular weight components. The PAH profiles of air samples within the industrial complex show a strong similarity to those of cokemaking plant samples. The concentrations and the specific content of benzo(a)pyrene in the iron and steel industrial complex are higher than those values measured in urban area, petrochemical industry park, and open‐air burning area.  相似文献   
56.
Bioavailabilities of metals in sediment to aquatic organisms depend on the strength of metal bonding to particulates. The accumulation tests of Cu and Cd in carp and in snails have been studied in vitro with the solution containing semisynthetic sediment samples in which the contents of various speciation of metal in sediment have been extended. For carp, the accumulation of Cu and Cd is related to the concentration of dissolved metal which in turn is affected by the distributions of speciations in sediment under given environmental conditions. It is another pattern for snails, various speciations of metal in sediment can contribute indirectly to metal accumulation. The contribution ratio, or relative importance of various speciations of metal in sediment can be expressed by multiple linear regression formulas. The contribution of ion‐exchangable speciation and coprecipition with carbonate speciation is 105 times larger than that of residue speciation in sediment.  相似文献   
57.
The linear alkylbenzenesulfonate (LAS) sorption on environmental sediments has been known long ago. Their high concentrations reflect the massive input of these chemicals from household and industrial uses. However few attempts were made to identify biodegradation metabolites of LAS in sediment. In this report, a method for the determination of these compounds in sediment samples by high‐performance liquid chromatography (HPLC) is described. The first step of our work was performed by solid‐phase extraction with octadecyl‐bonded silica (C18) mini‐columns and provided a suitable recovery of LAS (90 ± 5%) and most metabolites. Furthermore, laboratory investigations led to study the behaviour of LAS in sediment. The environmental samples used for this purpose were collected from a pond (named étang de Bolmon) located in the French Mediterranean coast. Our results were in agreement with an aerobic biodegradation process of LAS that occurred only with high values of sediment redox potential and needed the samples to be vigorously shaken to ensure adequate mixing and suspension of particulate material. In a stagnant sediment or under anaerobic conditions, LAS is not degraded. p‐Sulfophenylacetic acid and p‐sulfocinnamic acid were evidenced as predominant metabolites and were found not to be persistent.  相似文献   
58.
Abstract

Earlier papers indicated that the first incident of green discoloration in oysters (Crassostrea gigas) and the mass mortality observed in 1986 along the Taiwan Erhjin Chi coastal area were caused by the higher contents of total copper and copper species (mainly bioavailable and free ion) in sea water. the copper in sea water would be sorbed by suspended matter and transferred to sediments, and the copper in the sediments would also be desorbed to sea water. Processes of copper adsorption and desorption are the major factors influencing the contents of total copper and copper species in sea water and sediments. in this study, the Erhjin Chi sediments were mixed with sea water by a shaker technique. When the mixture was shaken for one hour, analogous to tidal mixing in estuaries, only copper desorption from sediments was observed. If the shaking time is increased for more than 3 hours, the copper released from the sediments was resorbed to the remaining solid phases. the higher the contents of mud (91.71%) and total copper (701 mg kg?1) in sediments, the higher the copper desorption rate (1.86 ppm hr?1) and copper adsorption rate (0.50 ppm hr?1) were observed. in sediments containing lower mud (0.80%) and lower copper (43.5 mg kg?1), the copper desorption and adsorption rates were 0.83 ppm hr?1 and 0.22 ppm hr?1, respectively. the interactions among the total copper and copper species in sea water and sediments, chemical and ecological parameters, and copper bioaccumulation in oysters in the Erhjin Chi estuarine and coastal area are also discussed.  相似文献   
59.
Metallurgical production is the largest polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) emission source in China. However, PCDD/F monitoring and research are rarely conducted on primary metallurgical production. In this study, a demonstration primary copper smelter in China was selected to investigate PCDD/F characteristics and control. Samples were collected from major PCDD/F release points in the smelter process (fly ashes and waste water sludge). Specific analysis of PCDD/F congeners was carried out using a high resolution gas chromatography/high resolution mass spectrometry method. The results showed that PCDD/Fs might be unintentionally produced in the primary copper smelter processes, with sample concentrations of 180–6110 pg/g dry wt; highly chlorinated PCDD/F homologues were predominant. The toxicity of all the samples was calculated to be 120 pg WHO TEQ/g, fly ashes from the refining process furnaces air pollution control device and sludge were hazardous waste with higher PCDD/F toxicity. Both precursor formation and de novo synthesis were found to contribute to PCDD/F formation in the smelter process. PCDD/F characteristics and formation were compared with reported secondary copper smelters. Life-cycle control of PCDD/F was proposed for retrofitting of this smelter and for similar plants in China's primary copper production sector, including control at the PCDD/F formation, removal and disposal stages.  相似文献   
60.
The overall effect of the number of boats on the copper (Cu) levels in the water column and sediment, along with their spatial variability within Shelter Island Yacht Basin (SIYB), San Diego Bay, California was examined. We identified a horizontal gradient of increasing dissolved Cu and Cu in sediment from outside to the head of SIYB which was coincident with the increasing number of boats. Spatial models of Cu distribution in water and sediment indicated the presence of ‘hotspots’ of Cu concentration. From outside to the head of SIYB, dissolved Cu ranged from 1.3 μ g L?1 to 14.6 μ g L?1 in surface water, and 2.0 μ g L?1 to 10.2 μ g L?1 in bottom water. Cu in sediment exceeded the Effect Range Low of 34 mg kg?1 (i.e. where adverse effects to fauna may occur), with a peak concentration of 442 mg kg?1 at the head of the basin. Free Cu++ in surface water was several orders of magnitude higher than in sediment porewater. High-resolution data of Cu species together with probability maps presented in this paper will allow managers to easily visualise and localise areas of impaired quality and to prioritise which areas should be targeted to improve Cu-related conditions.  相似文献   
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