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1.
Samples of humic substances were obtained from a waterworks at Fuhrberg, Germany. The material had a bimodal molecular size distribution with 40% of the total carbon in the 50,000–100,000-D (nominal molecular weight, NMW, in daltons) size fraction and 50% of the carbon in the <10,000-D (NMW) size fraction. The fulvic and humic acids isolated from the bulk humic substances were low in nitrogen content and had low H/C atomic ratios. Furthermore, the fulvic and humic acids had very similar elemental, spectral and copper binding characteristics. Over 70% of the carbon in both the fulvic and humic acids was present in aromatic or aliphatic groups, with 13C NMR analyses indicating approximately even distribution among the two types. Competitive elemental binding studies indicated that Ca2+, Mg2+, Al3+ and Fe3+ do not effectively compete for copper binding sites on these compounds. In humic acids, these cations are predominantly bond by carboxylic groups.  相似文献   

2.
The decline of cadmium pollution in fish farms is needed by any adequate method. The present study was designed to explore the effect of dietary cadmium contamination and its amelioration by using dietary clay, probiotic (Bactocell®), vitamin C, and vitamin E supplementation in Nile tilapia fish diet on growth rate, feed efficiency, blood components, and cadmium residues. Fish were separated into 15 groups, each group of fish was stocked into three aquaria and each contains 20 fishes. The fish of the first five groups were fed the basal diet, the second five groups were fed the basal diet contaminated with 25 mg cadmium/kg, and the third five groups were fed the same diet contaminated with 50 mg cadmium/kg. Within each dietary cadmium level, the first group was fed the diet without any supplementation, the second was fed the diet supplemented with natural clay (bentonite) at level 3%, the third group was fed the diet supplemented with 1 g Bactocell®/kg, the fourth group was fed the diet supplemented 50 mg vitamin E/kg, and the fifth group was fed the diet supplemented with 100 mg vitamin C/kg. Live body weight, daily body weight gain, and feed intake of Nile tilapia decreased significantly (P < 0.001) with increasing dietary cadmium level, while feed conversion was impaired. Fish group fed on diets contaminated with 50 mg cadmium/kg recorded the lowest live body weight and weight gain. Serum total protein and albumin concentration significantly (P < 0.001) decreased, while serum creatinine, AST, and ALT significantly (P < 0.001) increased with increasing cadmium level in fish diets. Blood hemoglobin and total erythrocyte (RBCs) significantly (P < 0.001 or 0.05) decreased with cadmium contamination in fish diets, while leukocytes were insignificantly affected. Body cadmium residues increased significantly (P < 0.001) by increasing cadmium level in fish diets. Live body weight, daily body weight gain, and feed intake of Nile tilapia increased significantly (P < 0.001) with feed additive supplementation in diets, also while feed conversion improved. Fish group fed on diets supplemented with probiotic Bactocell® or natural clay recorded higher body weight and gain rate than the other experimental groups. Serum total protein, blood hemoglobin, and total erythrocyte increased, while urea-N, creatinine, ALT, AST, and leukocytes decreased as affected with the feed additive supplementation. Feed additive supplementation in fish diets significantly (P < 0.001) decreased cadmium residues in fish bodies. Irrespective of dietary cadmium level, feed additive supplementation in fish diet improved the growth rate and decreased the concentrations of serum creatinine and ALT. The obtained results indicated that feed additive supplementation could modify the function of the kidney and liver in fish exposed to the cadmium toxicity.  相似文献   

3.
A reverse-phase high pressure liquid chromatography/mass spectrometry (HPLC/MS method was developed for estimating n-octanol/water partition coefficients (Kow) of anthropogenic molecules in complex chemical mixtures (e.g., complex effluents and solid waste leachates). The average error for an estimated log Kow was ca. 0.5 and this error was similar for both aliphatic and aromatic compounds. The minimum level of detection using the total ion current profile generally decreased with increasing molecular weight between 100 and 600 daltons. Results obtained demonstrate that the HPLC/MS method is a viable technique for estimating log Kow's of anthropogenic chemicals in complex environmental samples.  相似文献   

4.
Nephrops norvegicus were exposed simultaneously to cadmium, copper and zinc over an 18-day period. Exposure concentrations were control, 1, 5 and 25 microg litre(-1) for cadmium and copper and 8, 40 and 200 microg litre(-1) for zinc. Concentrations of cadmium, copper, zinc and metallothionein were measured in homogenates of both the gill and the hepatopancreas. Quantification of metallothionein was carried out by differential pulse polarography. Cadmium concentrations increased significantly in the gill and hepatopancreas of both male and female animals in response to increases in exposure concentration. In contrast, the concentration of copper and zinc increased significantly in the gills of males, but not in females. In the hepatopancreas, neither copper nor zinc resulted in significant changes in concentrations of these metals. Metallothionein concentrations in the gill and hepatopancreas were increased significantly in relation to metal exposure in both males and females. Concentrations of cadmium and metallothionein in both the gill and hepatopancreas of males and females were positively correlated. Copper in the hepatopancreas also showed positive relationships with MT concentrations in males, but not in females. This study suggested that cadmium MTs in the gill and hepatopancreas of Nephrops norvegicus could be used as a sensitive tool to detect cadmium contamination in the lobsters, although this was not true for copper and zinc.  相似文献   

5.

The adverse impacts of lead and cadmium exposure on health outcomes have been reported in the past. Few studies have been conducted on the relationship between lead and cadmium exposures and disability. We evaluated whether lead and cadmium exposures were associated with functional dependence including the total number of disabilities, activities of daily living (ADL), instrumental activities of daily living (IADL), leisure and social activities (LSA), lower extremity mobility (LEM), and general physical activities (GPA) in an elderly population. A total of 5513 eligible subjects were enrolled in the study from the National Health and Nutrition Examination Survey 2001–2006. Serum lead and cadmium exposure assessments were performed using atomic absorption spectrometry. Functional dependence was assessed by 19 structured questions. The relationships between lead and cadmium exposures and functional dependence were investigated using by multivariable linear regression models. Q2, Q3, and Q4 of lead exposure were significantly associated with the total number of disabilities, with β coefficients of ??0.62 (95% CI ??0.99, ??0.24), ??0.64 (95% CI ??1.02, ??0.26), and ??0.81 (95% CI ??1.19, ??0.42), respectively. This relationship remained significant in males. Furthermore, we analyzed the relationships between lead and cadmium exposure quartiles and various functional dependence metrics, and we determined that lead content was significantly associated with decreased ADL, LEM, and GPA (p?<?0.05) and cadmium content was inversely associated with ADL (p?<?0.05). Our study demonstrated a strong relationship between exposure to lead and cadmium and functional dependence in an elderly population.

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6.
In this study we evaluated the differences between concentrations of copper, iron, zinc, manganese, lead and cadmium in three terrestrial gastropods: Helix pomatia, Helix aspersa and Arion rufus, collected in a semi-rural location in Northern Italy. Metal concentrations in the foot and in the digestive gland were measured. In the hepatopancreas, copper and zinc did not differ significantly in the three species; the levels of copper were also similar in the foot. In comparison to Helix sps., A. rufus demonstrated lower concentrations of manganese and cadmium in the hepatopancreas and higher concentrations in the foot. In the slug the mucus produced in the foot could represent an efficient elimination mechanism of some elements. We also investigated correlations between the trace element content in the soft tissues and the mollusk size (weight of the body and height of the shell).  相似文献   

7.
The consumption of halieutic products has many health benefits. However, their contaminants loads need to be addressed to better understand the risk from consuming these products. The aquatic biota from the Baie des Chaleurs in New Brunswick is contaminated by cadmium, zinc and lead. In spite of this, no study has examined the heavy metal concentrations in commercial halieutic products sold in this Canadian region. The objective of this pilot study was to characterize the species and origin of fish and seafood sold in the Baie des Chaleurs region by using an ecosystemic approach. Additionally, a baseline picture of the heavy metal levels found in these products has been determined. In 2008, interviews were carried out in markets located in the Baie des Chaleurs area. Species that were identified as the most purchased were then bought for analysis. Samples were freeze-dried and homogenized before nitric acid digestions. Aluminum, copper, cadmium, iron, manganese, and zinc concentrations were determined by inductively coupled plasma optical emission spectrometry. Results show that 36 % of seafood species sold in markets were caught in the Baie des Chaleurs. Lobsters, shrimps, scallops and oysters are the most purchased species regardless of the season. High amounts of cadmium exceeding tolerable daily intake are found in lobster hepatopancreas and can cause deleterious effects on health, in particular in vulnerable populations such as children and heavy consumers. The ecosystemic approach to health used in this pilot study shows the feasibility of an exhaustive study on the exposure of coastal population to heavy metal from fish and seafood consumption and the source of halieutic products sold in markets.  相似文献   

8.
Polychlorinated naphthalenes (PCNs) and non-ortho chlorinated biphenyls (non-ortho CBs) were analysed in blubber, nuchal fat, liver, muscle, kidney and brain of three male harbour porpoises (Phocoena phocoena) from the west coast of Sweden. To estimate spatial variation, PCNs and non-ortho CBs were analysed in six blubber samples collected at different anatomical sites of each animal. Highest wet weight concentrations of ΣPCNs were detected in the lipid rich tissues (blubber and nuchal fat) and liver (520–730 and 520 pg/g, respectively) and lowest in brain (22 pg/g). TetraCNs were most abundant in muscle, kidney and brain, while the hexaCNs were most abundant in the lipid rich tissues and liver. The highest lipid weight concentration recorded (11 ng/g) was for the hexaCN congeners no. 66/67 in liver. These coeluting hexaCN congeners accounted for 80–100% of total hexaCNs in all tissues examined.Concentrations of Σnon-ortho CBs were highest in lipid rich tissues (220–280 pg/g wet weight). Non-ortho CB no. 77 and 169 constituted between 62–86% and 4.9–9.3%, respectively, of total Σnon-ortho CBs. No major variation of Σnon-ortho CB concentrations was found between the six different blubber sites but higher ΣPCN concentrations (wet weight) were found dorsally at the peduncle. Toxic equivalent concentrations (TEQs) showed that non-ortho CB no. 126 was the main contributor to total TEQs in all tissues, except liver in which hexaCN congener nos. 66/67 contributed to about 50% of total TEQs.  相似文献   

9.
Tissue cadmium levels and the amount of metal associated with the various protein fractions thereof have been determined in specimens of Mytilus edulis exposed to cadmium in the water and by direct injection. In addition to metallothionein, heavy-molecular weight proteins are involved in cadmium retention.  相似文献   

10.
Wu CC  Pu YS  Wu HC  Yang CY  Chen YC 《Chemosphere》2011,83(8):1188-1191
Prostate cancer associated with cadmium exposure may indicate a link between prostate specific antigen (PSA) and levels of blood cadmium (BCd) and urinary cadmium (UCd). Thus, these associations were investigated. We recruited 295 men, 50 years of age and above from a health check-up program at a health center as subjects of the study. They completed a self-reported questionnaire and provided fasting samples of blood and urine for cadmium assay. The assay was performed using atomic absorption spectrophotometry. Blood samples were also collected for the assays of total cholesterol and high-density lipoprotein measures. The means of BCd and UCd increased with age and the means of all subjects were 1.19 ± 1.04 μg L−1 and 1.37 ± 1.76 μg g−1 creatinine, respectively. The PSA levels were positively associated with the lipid levels, but reversely associated with BCd and UCd levels. The multivariate logistic regression analysis showed that men with PSA ? 4.0 ng mL−1 had an odds ratio (OR) of 0.4 (95% CI = 0.1-0.9) to have BCd > 0.49 μg L−1, and an OR of 0.4 (95% CI = 0.2-1.0) to have UCd > 0.45 μg g−1 creatinine. In conclusion, the PSA levels are reversely associated with BCd and UCd levels.  相似文献   

11.
Hexabromocyclododecanes (HBCDs) are now emerging ubiquitous contaminants due to their wide usage, persistence and toxicities. To investigate the bioaccumulative characteristics of HBCDs, sediments, Winkle (Littorina littorea), crucian carp (Carassius carassius) and loach (Misgurnus anguillicaudatus) were collected from two streams near an E-waste dismantling site in China, and HBCD exposure test was then conducted on Chinese rare minnow. The concentration of HBCDs was 14 ng g−1 dry weight in sediments, 186, 377 and 1791 ng g−1 lipid weight in winkle, crucian carp and loach, respectively. γ-HBCD was found to be the dominant diastereoisomer in the sediments (63% of total HBCDs). However, α-HBCD was selectively accumulated in the biotic samples and contributed to 77%, 63% and 63% of total HBCDs in winkle, crucian carp and loach, respectively. Moreover, an enrichment of (−)-enantiomers of α- and γ-HBCD were found in the winkle. The reverse results were observed in the crucian carp and loach. Similar observations of diastereoisomeric and enantiomeric composition were obtained in Chinese rare minnow with those found in the crucian carp and loach. These results indicate that the freshwater species from the streams are contaminated by HBCDs. α-HBCD can be selectively accumulated in organisms and the accumulative characteristics are enantioselective among species.  相似文献   

12.
A nationwide investigation into polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in market seafood was conducted for the first time in this study. Total PCDD/F concentrations in fatty fish ranged from 0.13 to 8.64 pg g−1 wet weight (mean 2.05 pg g−1 wet weight), total PCB concentrations ranged from 38.9 to 3514 pg g−1 wet weight (mean 1133 pg g−1 wet weight), and total PBDE concentrations ranged from 42.8 to 913 pg g−1 wet weight (mean 322 pg g−1 wet weight). Corresponding mean toxicity equivalent (TEQ) values for total PCDD/F and dioxin-like PCB were 0.25 pg g−1 wet weight (WHO 98-TEQ) and 0.32 pg g−1 wet weight (WHO 98-TEQ), respectively. OCDD, PCB-138 and PBDE-47 were the dominant compounds according to their respective congeners. WHO 98-TEQ PCDD/PCDF/PCB for fatty fish and shell fish were 0.60 and 0.070 pg g−1 wet weight, respectively, lower than the standard set by the European Commission. The contamination levels and profiles were compared with those documented in previous publications.  相似文献   

13.
The results of tests for the purification of fish oils with activated carbon for industrial use are presented. The optimum parameters for the process of purification (granulation of the activated carbon, its dosage, the oil temperature, and the duration of mixing the oil with activated carbon) were previously established for the laboratory scale. The optimization of the process consisted of selecting purification parameters that would allow for maximum reduction of the toxic polychlorinated dibenzo-para-dioxins and polychlorinated dibenzofurans (PCDD/Fs) content, while retaining the favorable high fatty acid content [C20:5 n−3, eicosapentaenoic acid (EPA) and C22:6 n−3, docosahexaenoic acid (DHA)]. The use of that optimum parameters in industrial conditions confirmed the satisfactory results obtained in laboratory tests. Five types of oil derived from various Baltic fish were purified. Reduction in the PCDD/Fs content was 77.0–93.6% on average, whereas in the dioxin-like polychlorinated biphenyls (dl-PCBs)—it was 42.7–50.5% on average, with insignificant changes in the total amount of EPA and DHA content. Furthermore, a significant reduction in the content of arsenic was noted (by about 62% on average), with insignificant changes in the content of organochlorine pesticides (OCPs), and marker polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), cadmium, lead, and mercury.Purification provided fish oil having standardized parameters that allow for its use as feed additives, whilst retaining its favorable fatty acid content.  相似文献   

14.
Dwyer J  Kavanagh L  Lant P 《Chemosphere》2008,71(9):1745-1753
The aim of this study was to examine the simultaneous degradation of dissolved organic nitrogen (DON) and associated colour from wastewater containing melanoidins by an advanced oxidation process (AOP). UV irradiation of H2O2 was used as the mechanism to create the hydroxyl radical for oxidation. Melanoidins are large nitrogenous organic compounds that are refractory during biological wastewater treatment processes. The simultaneous degradation of DON and colour, present as a result of these compounds, was investigated using an AOP. The oxidation process was much more capable of removing colour (99% degradation), dissolved organic carbon (DOC) (50% degradation) and DON (25% degradation) at the optimal applied dose of hydrogen peroxide for the system (3300 mg l(-1)). This indicated that colour and DON removal were decoupled problems for the purpose of treating melanoidin by an AOP and thus colour removal can not be used as an indication of DON removal Colour was caused by organic molecules with molecular weight greater than 10 kDa. Oxidation caused a partial reduction of the DON (41-15% of the total dissolved nitrogen) and DOC (29-14% of the DOC) associated with the large molecular weight fraction (>10 kDa) and almost complete colour removal (87-3% of the total colour). The degraded DON was mostly accounted for by the formation of ammonia (31% of the nitrogen removed from the large fraction) and small molecular weight compounds (66% of the nitrogen removed from the large fraction). The degraded DOC appeared to be mostly mineralised (to CO2) with only 20% of the degraded compounds appearing as small molecular weight DOC.  相似文献   

15.
The natural background of cadmium content in meat, liver and kidney from 287 cattle from a non polluted area in the subalpine region of Bavaria has been analyzed during the period from 1972 to 1975. The cadmium content in meat was always below the detection limit of 0.005, in liver between < 0.005 to 1.65 (median 0.050) and in kidney 0.008 to 1.95 (median 0.229) ppm Cadmium in fresh weight. The cadmium contents are discussed and compared with preliminary suggestions for cadmium tolerance levels and their consequence for food inspection.  相似文献   

16.
During ovary maturation of crabs, vitellogenin (Vg), a precursor molecule of vitellin (Vn) needed for embryogenesis, can be produced in large quantities in the hepatopancreas and then transported to the ovary by the hemolymph. In the present study, effects of Cd on Vg accumulation in the hepatopancreas and Vg transportation of the freshwater crab Sinopotamon henanense were investigated. We also studied the impacts of Cd on the mRNA expression of genes involved in energy metabolism, protein metabolism, and metallothionein (MT) and glutathione (GSH) synthesis. After Cd treatment, the Vg concentration and the Vg mRNA expression in the hepatopancreas were downregulated. Pearson’s correlation coefficient showed that the Vg level in the hepatopancreas correlated positively with those of the ovary and hemolymph (correlation coefficients 0.844 and 0.749, respectively), suggesting that the Vg transport from the hepatopancreas to the ovary can be impaired by Cd. The levels of carbohydrate and protein in the hepatopancreas of Cd-exposed crabs were decreased, and an inhibited protein metabolism was also observed. Energy production related isocitrate dehydrogenase and cytochrome C oxidase mRNA expressions, and MT and GSH synthesis increased after 10 days of Cd treatment and decreased after 20 days. Cd also caused a time-dependent upregulation of malondialdehyde. Our findings showed that Cd decreased Vg accumulation in the hepatopancreas due to partially excessive energy consumption and an activated defense system in the hepatopancreas, suggesting a possible regulatory mechanism in S. henanense which is the competitive advantage of energy reserves in metabolic Cd stress responses over the high-energy flux during vitellogenesis to ensure a continuous supply of metabolic energy. Moreover, the damage of Vg accumulation in the hepatopancreas caused by Cd could lead to an insufficient accumulation of Vn in the ovary and cause a retardation of oocyte development.  相似文献   

17.
Using a novel sampler, particulate organic compounds were collected in Santiago de Chile from June 9 to August 10, 1997. This sampler consists of a diffusion denuder to remove gas-phase organics prior to particle collection, a Teflon filter, and a PUF cartridge downstream of the filter. PAHs and n-alkanes were measured using gas chromatography/mass spectrometry analysis. Volatilization of particles collected on the Teflon filter varied from 15 to 85% for both n-alkanes and PAHs, with strong dependence on molecular weight. The relative distribution of n-alkanes and the values of molecular diagnostic ratios, such as Carbon preference index, indicated a mixed origin with strong anthropogenic input. Indeed, CPI values ranged from 0.66 to 1.96 (for the whole range of n-alkanes). The percent contribution of leaf “wax” n-alkanes (4.55–20.83%) indicated the low contribution of biogenic sources. In addition, the distribution pattern of PAHs was characteristic of anthropogenic emissions. The dominant contribution of combustion-related PAHs (CPAHs), 74–84%, indicated that vehicular emissions was the major source of PAHs.  相似文献   

18.
镉胁迫对向日葵幼苗生长和生理特性的影响   总被引:7,自引:0,他引:7  
采用溶液培养方法,研究了不同浓度镉(0、0.05、0.1、0.5和1 mg/L)处理7 d对向日葵幼苗生长和生理特性的影响。结果表明:随着镉处理浓度的增加,向日葵幼苗对镉的吸收显著增加。1 mg/L镉浓度处理时,叶、茎和根中镉浓度分别为0.05 mg/L镉处理时的16.3、19.2和581倍;根中积累的镉含量明显高于叶和茎, 各浓度根部积累的镉分别为叶和茎的37.8~63倍和29.4~41倍。镉胁迫显著抑制向日葵幼苗生长和叶绿素合成,当镉浓度达1 mg/L时,整株植物生物量和总叶绿素含量分别为对照的55.9%和52.6%。镉胁迫下向日葵幼苗游离脯氨酸和丙二醛(MDA)含量显著增加,1 mg/L镉浓度时,根中含量分别为对照的4和5.8倍。向日葵幼苗可溶性蛋白含量和过氧化物酶(POD)活性变化与镉胁迫浓度呈明显的倒U字型关系,可溶性蛋白含量在0.05 mg/L镉浓度时达到最大值,叶、茎、根中的POD活性分别在0.1、0.1和0.05 mg/L镉浓度时达到最大值。  相似文献   

19.
石化综合污水处理厂出水溶解性微生物产物的特性   总被引:2,自引:0,他引:2  
溶解性微生物产物(soluble microbial products,SMP)是生化系统出水残留COD的主要组成部分,通过采用分子量截留超滤分离、有机物树脂分离等方法对某石化综合污水处理厂出水SMP的分子量分布、亲水特性进行了分析研究.结果表明,水样中的SMP占出水残留COD的85%左右。SMP中主要成分是蛋白质,出水中小于1 kDa的有机物是SMP中的主要物质。树脂分离实验表明,亲水性有机物和疏水酸性有机物分别约占出水SMP的50%和20%,是需要进一步处理削减的主要物质类别。  相似文献   

20.
Wu SP  Tao S  Liu WX 《Chemosphere》2006,62(3):357-367
The size distributions of 16 polycyclic aromatic hydrocarbons (PAHs) and particle mass less than 10 microm in aerodynamic diameter (Dp) were measured using a nine-stage low-volume cascade impactor at rural and urban sites in Tianjin, China in the winter of 2003-2004. The particles exhibited the trimodal distribution with the major peaks occurring at 0.43-2.1 and 9.0-10.0 microm for both urban and rural sites. The concentrations of the total PAH (sum of 16 PAH compound) at rural site were generally less than those of urban site. Mean fraction of 76.5% and 63.9% of the total PAH were associated with particles of 0.43-2.1 microm at rural and urban sites, respectively. Precipitation, temperature, wind speed and direction were the important meteorological factors influencing the concentration of PAHs in rural and urban sites. The distributions of PAHs concentration with respect to particle size were similar for rural and urban samples. The PAHs concentrations at the height of 40 m were higher than both of 20 and 60 m at urban site, but the mass median diameter (MMD) of total PAH increased with the increasing height. The mid-high molecular weight (278 >or= MW >or= 202) PAHs were mainly associated with fine particles (Dp or=MW >or=178) PAHs were distributed in both of fine and coarse particle. The fraction of PAHs associated with coarse particles (Dp>2.1 microm) decreased with increasing molecular weight. The relatively consistent distribution of PAHs seemed to indicate the similar combustion source of PAHs at both of rural and urban sites. The fine differences of concentration and distribution of PAHs at different levels at urban site suggested that the different source and transportation path of particulate PAHs.  相似文献   

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