耕地土壤中交换态钙镁铁锰铜锌相关关系研究

应用主成份分析、聚类分析和相关性分析对沈阳市郊区1994个耕地土壤样本(0-20cm)的交换态钙、镁、铁、锰、铜、锌含量进行研究，结果表明，影响钙与镁、铁与锰、铜与锌分布的主因子分别在相同的主成份组中，钙与镁、铁与锰、铜与锌之间的相关系数较大，铁、锰、铜、锌之间均为极显著正相关关系，钙与铁、锰、铜、锌均为负相关关系，说明元素的生物地球化学属性对其地理分布有较大的影响。     

Fractionation of Mn, Fe, Zn and Cu in Sediments of Khor Kalabsha, Lake Nasser, Egypt

Khor Kalabsha is the second largest Khor in Lake Nasser, which is a freshwater side-branch of the main lake. Chemical analysis of the samples indicates that calcium carbonate and organic matter content in the surface sediments average 17.8 and 3.07%, respectively. Moreover, manganese, iron, zinc and copper concentrations are lower in Khor Kalabsha than in other lakes of Egypt. It has been found that both oxides and residual forms constitute the major part of the measured elements in the study area, while manganese and iron play an important role in building up clay minerals. It is noted that both zinc and copper fractions are controlled by biological and biochemical processes.     

Concentrations of Mn,Fe, Cu,Zn and Cd in the mesopelagic decapod Systellaspis debilis from the East Atlantic Ocean

Specimens of the oceanic decapod Systellaspis debilis were collected from six sites in the East Atlantic Ocean between 1970 and 1984, and were analysed for Mn, Fe, Cu, Zn and Cd. The data confirm that there are small but significant differences in mean metal concentrations from some sites which showed no obvious pattern in relation to geographic location of the samples. As a result, ranges of site means are quoted as baseline levels for each metal (g g^-1 dry wt): 2.3 to 2.9 g Mn g^-1, 31.2 to 77.8 g Fe g^-1, 25.9 to 83.4 g Cu g^-1, 41.9 to 92.9 gZn g^-1, 11.1 to 31.8 g Cd g^-1. The concentration of cadmium in S. debilis from all sites was raised relative to cadmium concentrations reported for coastal decapods, perhaps as a result of dietary enrichment. Metal accumulation may provide useful information for understanding the complex feeding behaviour of many oceanic animals.     

Fractionation of trace metals (Mn,Zn, Cu,Pb) in Red Sea sediments,Gulf of Aden,Yemen

A sequential extraction technique was applied to estimate the chemical association of Mn, Zn, Cu and Pb in five chemical phases (exchangeable, carbonate, Fe–Mn oxides, organic matter and residual) in sediments of the Gulf of Aden, Yemen. The results indicated that a higher level of Mn was associated with the residual fraction (natural sources) than the non-residual fraction (anthropogenic sources). Zn fractionations revealed that it was associated more with Fe–Mn oxides and organic fractions than exchangeable and carbonate fractions. Most of the Cu was present in the residual form (60–72%) except for in the main port area (zone III), where it was associated with the organic phase (77% of the total Cu content, the organic matter content was 5%). Similarly, most Pb was bound in the residual fraction (56–71%) except the main port area where ～ 62% of the total Pb was bound in non-residual fractions. It was also found that the Pb concentration in the exchangeable fraction was very high compared with other metals. The risk assessment code for the metals showed a low risk for Zn and Cu, but low to medium risk for Mn. Fractionation of Pb showed medium risk at most of the regions except at the eastern area, which revealed a high risk for the aquatic environment.     

磷胁迫对水稻基因型根系形态及吸收铁锰铜锌的影响

采用营养液培养方法研究了缺磷胁迫下4种水稻基因型(90-90—1、金23A、90-68-1、CDR22)的根系形态变化情况及其吸收微量元素铁、锰、铜、锌的影响。结果表明，(1)磷胁迫下，每个基因型在磷胁迫下其根系形态发生了明显变化、如根长、根冠比均呈增加趋势，并且根表有红棕色铁氧化物膜包被。(2)磷胁迫下根系形态的变化影响了水稻对生长介质中铁、锰、铜、锌的吸收：正常水稻植株中铁、锰、锌的含量高于磷胁迫植株，其中磷营养状况对水稻吸收铁、锰影响最明显；而磷营养状况对水稻植株铜含量的影响与铁、锰、锌正好相反，且影响程度较小。     

Heavy metals availability (Fe, Mn, Zn, Cu and Cr) in Aden Gulf sediments under aerobic and anaerobic conditions

The present study aims to analyse the chemical speciation of heavy metals in relation to aerobic and anaerobic conditions. Two sediment samples (from the Gulf of Aden, Yemen) were incubated under flooded conditions. In particular, the chemical forms of Fe, Mn, Zn, Cu and Cr under the experimental conditions were studied using a sequential chemical extraction method. The pH and Eh of the suspension were measured as critical parameters controlling the fate of the metals in the environment. The results showed that the metals concentration in the different forms varied with time incubation and affected by the variation of redox potential and pH value. Also, the changes in both redox potential (Eh) and pH values had evident effects on heavy metals transformation. It is obvious that the highest redox potential affected the amount of iron and manganese in the oxides form. When the redox potential decreased to-133 and-170 mV, it caused a significant transformation of the Fe-Mn oxide form to the water-soluble and exchangeable fractions. Under anaerobic conditions, the relative percentage of all five metals including the summation of four fractions (the water-soluble and exchangeable, carbonate, oxides and organic fractions) constituted 45-60% of the total amount of iron, 33-50% for manganese, 33-63% for Zn, 63-74% for Cu and 19-43% for Cr. Both zinc and copper among water-soluble and exchangeable fraction were high at the end of incubation period, this accompanied by a significant decrease in the content of the organically bound fraction. In general, the reducing conditions were more favorable for metal bound to water soluble and exchangeable fraction.     

Population health risk via dietary exposure to trace elements (Cu,Zn, Pb,Cd, Hg,and As) in Qiqihar,Northeastern China

The estimated daily intakes (EDIs) of six trace elements (Cu, Zn, Pb, Cd, Hg, and As) in vegetables (leafy vegetable, i.e., bok choy, fruit vegetables, i.e., cucumber and tomato, and other categories, i.e., mushroom, kidney bean, and potato), cereals (rice and wheat flour), and meats (pork, mutton, and beef) most commonly consumed by adult inhabitants of Qiqihar, Northeastern China, were determined to assess the health status of local people. The average EDIs of Cu, Zn, Pb, Cd, Hg, and As were with 20.77 μg (kg bw)^?1 day^?1 of Cu, 288 μg (kg bw)^?1 day^?1 of Zn, 2.01 μg (kg bw)^?1 day^?1 of Pb, 0.41 μg (kg bw)^?1 day^?1 of Cd, 0.01 μg (kg bw)^?1 day^?1 of Hg, and 0.52 μg (kg bw)^?1 day^?1 of As, respectively, which are below the daily allowance recommended by FAO/WHO. However, the maximum EDIs of Pb and Cd were 4.56 μg (kg bw)^?1 day^?1 and 1.68 μg (kg bw)^?1 day^?1, respectively, which are above the recommended levels [i.e., 3.58 μg (kg bw)^?1 day^?1 for Pb and 1.0 μg (kg bw)^?1 day^?1 for Cd] by FAO/WHO. This finding indicates that the potential health risk induced by daily ingestion of Pb and Cd for the local residents should receive a significant concern. Similarly, we detected elevated Pb and Cd concentrations, i.e., with average of 13.58 and 0.60 mg kg^?1 dw, respectively, in the adult scalp hairs. Consumption of rice, potato, bok choy, and wheat flour contributed to 75 and 82% of Pb and Cd daily intake from foodstuffs. Nevertheless, human scalp hair is inappropriate biological material for determination of the nutritional status of trace elements in this region.     

Seasonal variation and partition of trace metals (Fe, Zn, Cu, Mn, Cr, Cd and Pb) in surface sediments: relationship with physico-chemical variables of water from the Calabar River, South Eastern Nigeria

The seasonal variation and partition of trace metals (Fe, Cu, Zn, Mn, Cd, Cr and Pb) in the surface sediments of the Calabar River are reported. Chemical partition of the metals in the sediments reveals that 2–30% of the total metal load was contributed by the non-detrital (acid-soluble) fraction, while fine-grained host minerals/compounds are the main carriers of the detrital (acid-insoluble) fraction (70–98%). Using multivariate statistical analysis, the seasonal fluctuations in the distribution of some of the metals show significant influence by physio-chemical changes (dissolved oxygen, pH, salinity and conductivity) in the water column. Fe–Mn oxide grain coatings and sulphide materials have been identified as scavengers of some of the non-detrital and detrital trace metals in the sediments. On the basis of index of geoaccumulation (I-geo) and comparison with previous studies, the Calabar River surface sediments have been classified as unpolluted.     

肠道微生物对土壤中铜、锌、锰生物可给性的影响

为了更全面、准确地评价土壤中金属元素对人体的健康风险,研究土壤中金属元素在结肠阶段的生物可给性具有重要意义。通过采集我国一些地区的6种土壤,利用in vitro方法(PBET和SHIME联用)研究土壤中Cu、Zn、Mn在胃、小肠、结肠阶段的生物可给性。研究显示,土壤中Cu、Zn、Mn在胃阶段的生物可给性分别为23.8%~63.0%、21.2%~64.4%、11.7%~35.6%;从胃阶段到小肠阶段,土壤中Cu的生物可给性提高了0.4%~14.4%,而土壤中Zn在小肠阶段的生物可给性降低了6.7%~38.7%。结肠阶段,土壤中Cu、Zn、Mn的生物可给性分别为2.4%~12.9%、5.7%~18.7%、6.2%~18.9%,与小肠阶段相比,分别降低了21.7%~56.9%、0.4%~36.8%、4.5%~19.1%。结果表明,在肠道微生物存在的情况下,土壤中Cu、Zn、Mn在结肠阶段有较低的人体健康风险。     

Concentrations of V,Cr, Mn,Fe, Ni,Co, Cu,Zn, As and Cd in mesopelagic crustaceans from the North East Atlantic Ocean

Specimens of oceanic decapods, mysids and euphausiids, collected from the North East Atlantic Ocean during July 1985, were analysed for V, Cr, Mn, Fe, Ni, Co, Cu, Zn, As and Cd. Measurement of the metals was carried out using two techniques: inductively-coupled plasma-source mass spectrometry (ICP-MS) and atomic absorption (AAS). With the exception of the iron data, good agreement was observed between the data from the two techniques. Baseline-metal data are presented for the species measured, along with any effects of animal size on metal concentration. The data presented for oceanic animals from different trophic levels are important in studies of metal fluxes and for the assessment of markers within the food web in the oceans.     

The relationship between soil geochemistry and the bioaccessibility of trace elements in playground soil

A total of 32 samples of surficial soil were collected from 16 playground areas in Madrid (Spain), in order to investigate the importance of the geochemistry of the soil on subsequent bioaccessibility of trace elements. The in vitro bioaccessibility of As, Co, Cr, Cu, Ni, Pb and Zn was evaluated by means of two extraction processes that simulate the gastric environment and one that reproduces a gastric?+?intestinal digestion sequence. The results of the in vitro bioaccessibility were compared against aqua regia extractions (“total” concentration), and it was found that total concentrations of As, Cu, Pb and Zn were double those of bioaccessible values, whilst that of Cr was ten times higher. Whereas the results of the gastric?+?intestinal extraction were affected by a high uncertainty, both gastric methods offered very similar and consistent results, with bioaccessibilities following the order: As?=?Cu?=?Pb?=?Zn?>?Co?>?Ni?>?Cr, and ranging from 63 to 7?%. Selected soil properties including pH, organic matter, Fe and CaCO₃ content were determined to assess their influence on trace element bioaccessibility, and it was found that Cu, Pb and Zn were predominantly bound to organic matter and, to a lesser extent, Fe oxides. The former fraction was readily accessible in the gastric solution, whereas Fe oxides seemed to recapture negatively charged chloride complexes of these elements in the gastric solution, lowering their bioaccessibility. The homogeneous pH of the playground soils included in the study does not influence trace element bioaccessibility to any significant extent except for Cr, where the very low gastric accessibility seems to be related to the strongly pH-dependent formation of complexes with organic matter. The results for As, which have been previously described and discussed in detail in Mingot et al. (Chemosphere 84: 1386–1391, 2011), indicate a high gastric bioaccessibility for this element as a consequence of its strong association with calcium carbonate and the ease with which these bonds are broken in the gastric solution. The calculation of risk assessments are therefore dependant on the methodology used and the specific environment they address. This has impacts on management strategies formulated to ensure that the most vulnerable of society, children, can live and play without adverse consequences to their health.     

Tissue and sub-cellular distribution of Fe,Cu, Zn and 210Po in the abalone Haliotis rubra

The tissue and sub-cellular distribution of Fe, Cu, Zn and the naturally occurring radionuclide polonium-210 was determined in the gastropod mollusc Haliotis rubra collected from Western Port Bay, Australia, between March and July 1988. The highest concentrations of the metals, with the exception of Cu, were found in the digestive gland. Copper was more uniformly distributed, with tissues that are more vasculated having higher concentrations. Ultrastructural examination of the digestive gland, gill and kidney showed dense membrane-bound granules within the cytoplasm. Elemental analysis of the granules by electron probe x-ray microanalysis indicated that the granules in the digestive gland and gill contained high concentrations of iron, with small amounts of copper and zinc. In contrast, the metal-containing granules in the kidney were predominantly composed of iron, copper and phosphorus, with variable contributions of sodium potassium, and calcium. Homogenisation and fractionation of the digestive gland by differential centrifugation confirmed that approximately 80, 10, 90 and 50% of the total homogenate Fe, Cu, Zn and ²¹⁰Po, respectively, sedimented at 1200xg. In the haemolymph, all the elements studied were associated with the soluble high molecular weight component of the serum, not with the amoebocytes. ²¹⁰Po was present in the mucus-secreting hypobranchial glands at about half the concentration found in gill tissue.     

Strontium and its relationship with trace elements Mg,Cu, Co,and Mo in human blood and serum

The aim of the study was to assess the influence of exposure to strontium on human blood and serum concentrations of magnesium, copper, cobalt, and molybdenum. Inductively coupled plasma–mass spectrometry (ICP-MS) was used to analyze the elemental content of whole blood and blood serum of 97 healthy men including 70 workers in a thermal power plant and 27 control subjects from the rural area of Dragash (Kosovo), an environment without pollution. The results showed that chronic moderate exposure to strontium decreases the levels of copper in blood (BCu) and serum (SCu), of cobalt in blood (BCo) and serum (SCo), and of molybdenum in blood (BMo). All changes in blood and serum concentrations of these essential elements were significant but remained within the normal range. The results suggest that strontium may induce adverse health effects in humans.     

Study of the ambient air metallic elements Cr,Cu, Zn,Cd and Pb at HAF sampling sites

This study characterized diurnal variations in the compositions of total suspended particulates (TSP) and dry deposits of particulates from ambient air, and the metallic elements that are contained in them at harbor, airport and farmland (HAF) sampling sites from August, 2013 to July, 2014. Two-way ANOVA of the amounts of metallic elements in the TSP and dry deposits was carried out in all four seasons at the HAF sampling sites. The metallic elements Cr and Cu originated in local emission sources at the airport. Metallic elements Zn and Pb originated in local emission sources at the harbor. Finally, metallic element Cd originated in local emissions form farmland. The following results were also obtained. (1) The metallic composition of the TSP differed significantly from that of the dry deposits in all four seasons at the harbor and farmland sampling sites, but not at the airport sampling site. (2) High correlations coefficients were found between the amounts of metallic elements Cr and Cu in the TSP and those in the dry deposits at the airport sampling site. (3) Pb was present in the TSP and the dry deposits at the harbor sampling site.     

Molecular dynamics of stability and structures in phytochelatin complexes with Zn,Cu, Fe,Mg, and Ca: Implications for metal detoxification

Phytochelatins, or (γ-glutamyl-cysteine) _n -glycine, are specialized peptides produced by plants and algae to mitigate toxic metal exposure, for instance in response to high levels of metals such as Cu, Cd, and Zn. Stability constants and structural characterization of metal–phytochelatin complexes are lacking. This information is required to gain mechanistic insights on the metal selectivity of phytochelatins. Here, we studied structural coordination and thermodynamic stability by performing molecular dynamics simulations of a fully hydrated phytochelatin molecule complexed with Ca²⁺, Mg²⁺, Fe²⁺, Zn²⁺, and Cu²⁺. Our results predict the following decreasing order for the thermodynamic stability of the phytochelatin complexes: Zn²⁺ ≥ Cu²⁺ ≥ Fe²⁺ > Mg²⁺ > Ca²⁺. The favorable binding energies with Zn²⁺ and Cu²⁺ over the other metal cations can be explained by shorter binding distances and greater coordination from carboxylate and keto O atoms. Conformational rearrangement of phytochelatin following metal chelation was captured by monitoring changes in the solvent-accessible volume. Accessibility of solvent molecules to the phytochelatin structure was inversely proportional to the distance between the coordinated ligands and the chelated metal. These new findings demonstrate the influence of the metal–phytochelatin structure on the metal-binding thermodynamics and the phytochelatin conformation, both of which are important to evaluate the intracellular role of phytochelatin in mediating algal response to toxic heavy metal exposure.     

Seedling growth responses to soil resources in the understory of a wet tropical forest

Plant growth responses to resources may be an important mechanism that influences species' distributions, coexistence, and community structure. Irradiance is considered the most important resource for seedling growth in the understory of wet tropical forests, but multiple soil nutrients and species have yet to be examined simultaneously with irradiance under field conditions. To identify potentially limiting resources, we modeled tree seedling growth as a function of irradiance and soil nutrients across five sites, spanning a soil fertility gradient in old-growth, wet tropical forests at La Selva Biological Station, Costa Rica. We measured an array of soil nutrients including total nitrogen (total N), inorganic N (nitrate [NO3-] and ammonium [NH4+]), phosphate (PO4-), and sum of base cations (SBC; potassium, magnesium, and calcium). Shade in the forest understory did not preclude seedling growth correlations with soil nutrients. Irradiance was a significant predictor of growth in 52% of the species, inorganic N in 54% (NO3- in 32%; NH4+ in 34%), total N in 47%, SBC in 39%, and PO4- in 29%. Overall, growth was correlated with both irradiance and soil nutrients in 45% of species and with soil nutrients only in an additional 48%; rarely was irradiance alone correlated with growth. Contrary to expectations, the magnitudes of growth effects, assessed as the maximum growth response to significant resources for each species, were similar for irradiance and most soil nutrients. Among species whose growth correlated with soil nutrients, the rank importance of nutrient effects was SBC, followed by N (total N, NO3-, and/or NH4+) and PO4-. Species' growth responsiveness (i.e., magnitudes of effect) to irradiance and soil nutrients was negatively correlated with species' shade tolerance (survival under 1% full sun). In this broad survey of species and resources, the nearly ubiquitous effects of soil nutrients on seedling growth challenge the idea that soil nutrients are less important than irradiance in the light-limited understory of wet tropical forests.     

Radionuclides,trace elements,and radium residence in phosphogypsum of Jordan

Voluminous stockpiles of phosphogypsum (PG) generated during the wet process production of phosphoric acid are stored at many sites around the world and pose problems for their safe storage, disposal, or utilization. A major concern is the elevated concentration of long-lived ²²⁶Ra (half-life = 1,600 years) inherited from the processed phosphate rock. Knowledge of the abundance and mode-of-occurrence of radium (Ra) in PG is critical for accurate prediction of Ra leachability and radon (Rn) emanation, and for prediction of radiation-exposure pathways to workers and to the public. The mean (±SD) of ²²⁶Ra concentrations in ten samples of Jordan PG is 601 ± 98 Bq/kg, which falls near the midrange of values reported for PG samples collected worldwide. Jordan PG generally shows no analytically significant enrichment (<10%) of ²²⁶Ra in the finer (<53 μm) grain size fraction. Phosphogypsum samples collected from two industrial sites with different sources of phosphate rock feedstock show consistent differences in concentration of ²²⁶Ra and rare earth elements, and also consistent trends of enrichment in these elements with increasing age of PG. Water-insoluble residues from Jordan PG constitute <10% of PG mass but contain 30–65% of the ²²⁶Ra. ²²⁶Ra correlates closely with Ba in the water-insoluble residues. Uniformly tiny (<10 μm) grains of barite (barium sulfate) observed with scanning electron microscopy have crystal morphologies that indicate their formation during the wet process. Barite is a well-documented and efficient scavenger of Ra from solution and is also very insoluble in water and mineral acids. Radium-bearing barite in PG influences the environmental mobility of radium and the radiation-exposure pathways near PG stockpiles.     

Leaching-induced migration and compositional form change of Cu,Zn, and Cd from sludge to loess

Land utilization of sewage sludge has become one of the major issues in environmental mitigation in China. This is particularly important in the Loess Plateau of Northwest China. Sludge enriched with organic matter and nutrients might effectively help to resolve the problems of silty loess soils as evidenced by porosity defect, structural alterations and absence of fertility. After sludge flows into the loess, irrigation water contains heavy metals that leach and migrate into sludge and consequently related human health risks may occur that raise concerns; and this situation needs to be rectified. The characteristics of the vertical migration and composition form change of Cu, Zn, and Cd from composted sludge to loess, and corresponding influencing factors, were investigated by performing a soil column simulation test under the leaching treatment of a one-year irrigation water capacity. Results demonstrated that: (1) composted sludge significantly improved loess fertility, and irrigation leaching transported only a small quantity of organic matter in sludge in the plough layer; (2) although some of the Cu, Zn, and Cd in composted sludge migrated to and concentrated in the middle and upper layers of the soil column during leaching, these metals were mostly retained in the plough layer; and (3) after the leaching treatment of the one-year irrigation water capacity, the compositions of Cu, Zn, and Cd (particularly Cu and Zn) in both plough layer and loess began to stabilize with low concentrations in the exudate. These findings confirmed the applicability of composted sludge in loess regions. This study provided a new insight into the sludge reuse in alkaline soils in arid and semi-arid region.     

Geochemical anomalies in two sulfide-bearing waste disposal areas: Fe,Cu, Zn,Cd, Pb,and As in contaminated waters and snow,Kemerovo and Chelyabinsk regions,Russia

Sulfide-bearing mill wastes are sources of high concentrations of acid, soluble metals, Sb, and As. Contents of Cu, Zn, Fe, Pb, Cd, As, and Sb in wastes of the Belovo Zn-processing and the Karabash mineral-processing plants (Russia) exceed the average content in the upper continental crust and background soils. High-dissolved metal and As concentrations are found in acid drainages, which form as a result of interaction between sulfide wastes and water. Monitoring research using geochemical and geophysical methods was performed to evaluate the contamination of the surrounding area (water and bottom sediments in the contaminated rivers and snow cover). Zones of geochemical anomalies were identified where the concentrations of Fe, Cu, Zn, Cd, Pb, and As are 2–3 orders of magnitude higher than in drinking water standards (for rivers) and background levels (for snow). The use of geophysical methods allowed us to prove penetration of drainage solutions into the groundwaters. The total environmental damage caused by the pollution of water and land resources in the Belovo Zn-processing plant waste disposal area amounted to $156 million at the time of 2011, and could reach $480 million by 2030, if steps are not taken in recycling and remediation of disturbed areas.     

连续年龄序列桉树人工林土壤微量元素含量及其影响因素

对连续年龄序列(2 a、3 a、4 a、5 a、6 a)桉树人工林土壤三种微量元素(Fe、Mn、Zn)的含量及其影响因素进行了分析,探讨了土壤微量元素含量随林分年龄的变化规律.土壤养分之间的相关性分析表明,所有年龄阶段的桉树人工林中土壤Fe、Mn、Zn含量与土壤pH值之间呈极显著的正相关,说明土壤微量元素含量强烈受土壤酸度的影响.土壤三种微量元素含量与土壤全K、全ca、全Mg等大量养分元素含量之间均存在显著或极显著的正相关,而与土壤有机C、全N、全P的相关性不明显(0～20 cm表层土壤的Zn除外).总的来说,土壤微量元素含量随桉树人工林年龄的增加呈下降趋势,其中6 a生桉树人工林各土壤层(0～20 cm、20～40 cm、40～60 cm)的Fe、Mn、Zn含量分别比2a生林分下降13.7%～21.8%、55.6%～57.2%和71.0%～73.2%.在当前桉树人工林种植方式下,随着林分年龄的增加,应增施有机、无机肥和Fe、Mn、Zn等微量元素肥料,以有效控制土壤地力衰退和实现桉树人工林可持续经营.