Metal Tolerance Capability of <Emphasis Type="Italic">Helichrysum microphyllum</Emphasis> Cambess. subsp. <Emphasis Type="Italic">tyrrhenicum</Emphasis> Bacch., Brullo &amp; Giusso: A Candidate for Phytostabilization in Abandoned Mine Sites

Sardinia was known as an important mine pole in Europe during his history. Still after decades from mine closure, 75.000.000 m³ of mine waste, rich in heavy metals, were left abandoned causing a huge environmental legacy on the mine district area. Consequently, cost effective remediation is required. In this frame, phytoremediation is considered a feasible candidate. This research was focused on Helichrysum microphyllum subsp. tyrrhenicum, which is pioneer in xeric soils with low-functions, like mine tailings. The aim of this study was to evaluate its ability to extract heavy metals from mine soils and accumulate them in plant tissues and its suitability for phytostabilization. Sundry samples of soil, roots and epigean organ were collected through field sampling and analysed in order to obtain metals concentration and mineralogical characteristics. Our results indicate that this species tolerates high concentration of zinc, lead and cadmium, behaving as a species suitable for phytostabilization.     

山东省某轻稀土矿区粮食中稀土元素含量与健康风险

目的了解山东某轻稀土矿区与非矿区粮食中稀土元素含量及其健康风险。方法于2014年7—10月,采集调查区域内村民自己种植的粮食(小麦、玉米和大豆)样品339份,采用电感藕合等离子体质谱仪(ICP-MS)测定15种稀土元素的含量。结果矿区粮食中总稀土元素含量为9.85~4 268.39μg/kg,中位数为82.47μg/kg;非矿区粮食中总稀土元素含量为1.55~2 662.31μg/kg,中位数为54.75μg/kg。矿区和非矿区粮食中稀土元素含量差异无统计学意义(P0.05)。矿区和非矿区均为小麦稀土元素含量最高(128.79μg/kg和85.14μg/kg),玉米最低(44.89μg/kg和37.95μg/kg)。粮食中稀土元素以富集轻稀土元素为特征。通过粮食摄入的稀土元素远小于健康指导值。结论矿区和非矿区粮食中稀土元素含量无差异,以轻稀土元素为主,通过小麦、玉米、大豆摄入的稀土元素不会危害人体健康。     

The Enchytraeid Reproduction Test (ERT): A Potentially Quick and Affordable Tool for the Assessment of Metal Contaminated Soils in Emerging Economies

The enchytraeid reproduction test (ERT) was used to assess the ecotoxicity of selected mine tailings and agricultural soils from South Africa. The mine tailings had higher cumulative metal concentrations than agricultural soils. The most contaminated mine tailings significantly reduced the survival of the oligochaete Enchytraeus doerjesi whose reproduction was suppressed in all mine waste substrates. Because it reliably singled out the most contaminated substrate and was found easy to perform, we suggest that the ERT could be a quick and affordable tool for assigning intervention values for soil remediation in emerging economies such as South Africa.     

深圳近岸海域海洋动物稀土元素组成特征及配分模式研究

目的建立定量测定深圳近岸海域海洋动物稀土元素(REE)的方法,并对REE组成特征以及配分模式进行分析研究。方法在深圳近岸海域采集60份海洋动物样本,采用电感耦合等离子体质谱法(ICP-MS)测定钇、镧、铈、镨、钕、钐、铕、钆、铽、镝、铒、钬、铥、镱、镥等15种稀土元素,并选择国家一级标准物质茶叶(GBW10016)进行定量分析的质量控制。结果软体动物、藤壶、鱼类及虾类的REE平均测定值分别为(2.66±2.28)、(4.69±1.32)、(0.03±0.03)和(0.07±0.02)μg/g;所测海洋动物的稀土配分特征总体上都表现为轻稀土元素的富集。结论(1)球粒陨石标准化处理表明,藤壶、软体动物和虾类与南海北部陆坡海洋沉积物、香港土壤以及中国大陆土壤稀土平均值配分模式较接近,而鱼类的则有所差异;(2)双壳类软体动物由于体内REE总量较高而存在食用安全风险;(3)由REE富集能力、与海洋沉积物相似的REE配分模式以及附着生长特性等方面的特征显示,藤壶及牡蛎是较好的海洋环境REE指示动物。     

电感耦合等离子体质谱法测定化妆品中15种稀土元素

目的建立电感耦合等离子体质谱法同时测定化妆品中15种稀土元素的方法。方法样品经HNO3+H2O2微波消解后,应用电感耦合等离子体质谱技术检测。每个稀土元素选择一个不受同质异位素干扰的同位素89Y、139La、140Ce、141Pr、146Nd、147Sm、153Eu、157Gd、159Tb、163Dy、165Ho、166Er、169Tm、172Yb、175Lu共15种元素。结果15种稀土元素混合标准液浓度0.5～100.0μg/L时,相关系数达到0.9998以上。方法的回收率在89.3%～114.6%;样品精密度为1.45%～7.93%。实际样品测定,膏状样品检出La、Ce、Nd、Y,粉状样品除Tm、Lu外,其他13种元素均检出。结论电感耦合等离子体质谱法,操作简便,灵敏度高,准确度高,线性范围宽,适合化妆品中15种稀土元素的同时测定。     

山东省某轻稀土矿区水果和鸡蛋中稀土元素含量及健康风险

目的 了解山东轻稀土矿区与对照区水果和鸡蛋中稀土元素含量的差异及其健康风险。方法 分别采集稀土矿区和对照区附近村民自己种植的水果及自家家禽生产的鸡蛋样品,用电感藕合等离子体质谱法(ICP-MS)测定16种稀土元素含量。结果 矿区和对照区水果中总稀土元素含量分别为142.5 μg/kg和16.1 μg/kg,差异具有统计学意义;矿区核果、仁果、浆果中稀土元素含量分别为47.0 μg/kg、146 μg/kg和279 μg/kg,对照区分别为17.6 μg/kg、18.9 μg/kg和11.0 μg/kg,矿区和对照区仁果、浆果类水果中稀土元素差异均有统计学意义。矿区和对照区鸡蛋中总稀土元素平均值分别为4.32 μg/kg和3.25 μg/kg,差异无统计学意义。矿区和对照区样品中稀土元素均以轻稀土元素为主。矿区和对照区通过水果估计的每日稀土元素摄入量为0.58 μg/(kg·d)和0.067μg/(kg·d),通过鸡蛋估计的每日稀土元素摄入量为0.003 μg/(kg·d)和0.002 μg/(kg·d)。结论 矿区水果中稀土元素高于对照区,鸡蛋中稀土元素含量无差异,水果和鸡蛋均以富集轻稀土元素为特征,通过水果和鸡蛋摄入的稀土元素不会危害人体健康。     

Identification of Sesbania sesban (L.) Merr. as an Efficient and Well Adapted Phytoremediation Tool for Cd Polluted Soils

A pot experiment was carried out to assess Cd uptake and accumulation efficiency of Sesbania sesban. Plants were grown in soil spiked with 25, 50, 100, 150, 200, 250, and 300 mg/kg Cd. After 120 days, plants were harvested and analyzed for Cd content. A steady increase in Cd accumulation with increasing metal concentration in soil was observed for all treatments. Accumulation of Cd was greatest in roots (86.7 ± 6.3 mg/kg), followed by stem (18.59 ± 1.9 mg/kg), and leaf (3.16 ± 1.1 mg/kg). Chlorophyll content declined with increasing Cd concentration, while proline and protein content increased as compared to control. At higher Cd levels, root, shoot length, and biomass were all significantly reduced (p ≤ 0.001). An increase in total protein along with greater A₂₅₀/A₂₈₀ value suggested an increase in metal-protein complexes. Considering the rapid growth, high biomass, accumulation efficiency, and adaptive properties, this plant could be used as a valuable tool for the phytoremediation of Cd contaminated soils.

     

人肺癌和癌旁正常组织中稀土元素含量及分布

分析稀土元素 (REE)在肺癌及癌旁正常组织中的分布情况 ,比较肺癌患者与正常人肺组织中REE的含量及分布 ,为进一步研究REE与肿瘤的关系提供线索。用电感耦合等离子质谱仪 (ICP MS)方法测定了10例肺癌病人的癌及癌旁正常组织中 15种REE的含量 ,并与在同一实验室中用相同仪器条件测定的 13例正常人肺组织中REE的含量和分布进行了比较。样品在北京大学公共卫生学院中心仪器室测定 ,用光谱纯的铼 (Re)作为内标元素补偿 ,仪器可以自动校正氧化物的干扰。 15种REE的加标回收率在 92 9%～111 3%之间 ,变异系数在 0 96～ 3 0 7之间 ,方法的检出限为 0 0 0 5～ 0 0 2 5ng g。结果发现 :癌旁正常组织中15种REE的含量为癌组织中的 2 0 7～ 2 5 1倍 ;正常人肺组织中 ,除Ce外其他REE含量均低于癌旁正常组织 ,La、Pr、Nd的含量略高于肺癌组织 ,其他元素则低于肺癌组织。肺癌及癌旁正常组织REE的分布曲线基本一致 ,均有Ce的正异常 (δCe分别为 1 15 2和 1 2 37)和Eu的负异常 ((δEu分别为 0 5 72和 0 6 0 2 )。正常人肺组织REE的分布曲线Ce的正异常和Eu的负异常更明显 ,δCe=2 798,δEu=0 2 78。结果还显示正常人肺组织中轻稀土元素的配分显著高于肺癌和癌旁正常组织 ,中和重稀土配分则显著低于肺癌及癌旁正?     

Screening of Plant Species for Phytoremediation of Uranium,Thorium, Barium,Nickel, Strontium and Lead Contaminated Soils from a Uranium Mill Tailings Repository in South China

The concentrations of uranium, thorium, barium, nickel, strontium and lead in the samples of the tailings and plant species collected from a uranium mill tailings repository in South China were analyzed. Then, the removal capability of a plant for a target element was assessed. It was found that Phragmites australis had the greatest removal capabilities for uranium (820 μg), thorium (103 μg) and lead (1,870 μg). Miscanthus floridulus had the greatest removal capabilities for barium (3,730 μg) and nickel (667 μg), and Parthenocissus quinquefolia had the greatest removal capability for strontium (3,920 μg). In this study, a novel coefficient, termed as phytoremediation factor (PF), was proposed, for the first time, to assess the potential of a plant to be used in phytoremediation of a target element contaminated soil. Phragmites australis has the highest PFs for uranium (16.6), thorium (8.68), barium (10.0) and lead (10.5). Miscanthus floridulus has the highest PF for Ni (25.0). Broussonetia papyrifera and Parthenocissus quinquefolia have the relatively high PFs for strontium (28.1 and 25.4, respectively). On the basis of the definition for a hyperaccumulator, only Cyperus iria and Parthenocissus quinquefolia satisfied the criteria for hyperaccumulator of uranium (36.4 μg/g) and strontium (190 μg/g), and could be the candidates for phytoremediation of uranium and strontium contaminated soils. The results show that the PF has advantage over the hyperaccumulator in reflecting the removal capabilities of a plant for a target element, and is more adequate for assessing the potential of a plant to be used in phytoremediation than conventional method.     

微波消解/ICP-MS同时测定人参中15种稀土元素

目的:建立一种电感耦合等离子体质谱法测定人参中稀土元素的方法。方法:样品经HNO3+H2O2微波消解后,用ICP—MS测定89Y,139La,140Ce,141Pr,146Nd,147Sm,151Eu,157Gd,159Tb,163Dy,165Ho,166Er,169Tm,172Yb和175Lu共15种稀土元素。结果:15种稀土元素的检出限分别在0.24~2.46μg/kg之间,线性良好,相关系数≥0.9996。利用该方法分析了国家一级灌木枝叶标准物质(GBW 07604)、小麦粉标准物质(GBW 10011)和鸡肉标准物质(GBW 10018)中的稀土元素,结果与标准值一致,用该方法测定人参中的稀土元素,结果令人满意。结论:该方法质谱图简单,选择性和灵敏度好,定量准确,适用于人参中稀土元素的测定。     

Solubility of Trace Elements and Heavy Metals from Stabilized Sewage Sludge by Fly Ash

Stabilized sewage sludge (SS) by fly ash (FA) and alkaline mine tailing as artificial soil, to be applied on the ecological rehabilitation at mining junkyard, offers a potential viable utilization of the industrial by-product, as well as solves the shortage of soil resource in mine area. In this study, trace element and heavy metal soil solution concentrations arising from fly ash, sewage sludge, mine tailing, and artificial soil mixtures were investigated in a laboratory incubation. It was found that total Cd, Pb, and Zn contents in artificial soils were significantly lower than the control standards for pollutants in sludges from agricultural use (GB 4284-84). Soil solution Cd and Pb concentrations were obviously reduced by mixing sewage sludge with alkaline fly ash. Initial soil solution Cd, Pb, and Zn concentrations in artificial soils were 1.773–14.672, 4.05–24.95, and 133–608 μg L⁻¹, respectively, and after 35-days incubation, soil solution Cd, Pb, and Zn concentrations gradually decreased and were approaching control levels by the end of the experiment, and finial soil solution were decreased to 0.037–0.365, 2.12–7.34, and 29–509 μg L⁻¹, respectively.     

Distribution of Metals and Arsenic in Soils of Central Victoria (Creswick-Ballarat), Australia

A soil-sampling campaign was conducted to identify and map heavy-metal contamination in the Ballarat-Creswick area of Central Victoria, Australia, with respect to mining activities and natural background levels in soils. The distribution and concentrations of both lithology- (Fe, Al, and Mn) and pollution-sensitive elements (Zn, As, Pb, Cu, Cr, Ni, and Co) were documented in surface soils (approximately 0 to 10 cm, fraction <2 mm, n = 85). The total heavy-metal and metalloid contents in soils decreased in the order Fe >> Al >> Zn > Mn >> As > Pb > Cu ≈ Ni ≈ Cr > Co. Mean levels of Zn (273 mg/kg) and As (39 mg/kg) in soils were well above normal global ranges and could be of local importance as a source of contamination. Extreme soil levels of Ni, Cr, Pb, and Fe were found in old mining waste material and pointed to the anthropogenic influence on the environment. Most of the measured elements showed marked spatial variations except Co. As contents were significantly higher than the tolerable level (ANZECC (1992) guidelines), with values up to 395.8 mg/kg around the mine tailings site. Mn soil contents were strongly associated with Co and Ni contents in most soils. High Fe contents (average approximately 41,465 mg/kg) in soils developed on basalt bedrock were correlated with Zn contents (average 400 mg/kg), and it is highly likely that Fe-oxides serve as sinks for Zn under near-neutral soil pH (6.3) conditions. Between the two major bedrock lithologic units, Ordovician sediments and Tertiary basalt, a clear enrichment of metals was found in the latter that was reflected in high background levels of elements. Among the various size fractions, silt (average approximately 45.1%) dominated most of the soils. In general and with a few exceptions, the concentrations of measured elements did not show significant correlations to other measured soil parameters, e.g., clay, silt and sand size fractions, organic matter, soil pH, and cation exchange capacity.     

Prosopis pubescens (Screw Bean Mesquite) Seedlings are Hyperaccumulators of Copper

Due to health reasons, toxic metals must be removed from soils contaminated by mine tailings and smelter activities. The phytoremediation potential of Prosopis pubescens (screw bean mesquite) was examined by use of inductively-coupled plasma optical emission spectroscopy. Transmission electron microscopy was used to observe ultrastructural changes of parenchymal cells of leaves in the presence of copper. Elemental analysis was used to localize copper within leaves. A 600-ppm copper sulfate exposure to seedlings for 24 days resulted in 31,000 ppm copper in roots, 17,000 ppm in stems, 11,000 in cotyledons and 20 ppm in the true leaves. For a plant to be considered a hyperaccumulator, the plant must accumulate a leaf-to-root ratio <1. Screw bean mesquite exposed to copper had a leaf-to-root ratio of 0.355 when cotyledons were included. We showed that P. pubescens grown in soil is a hyperaccumulator of copper. We recommend that this plant should be field tested.     

Normal value of resting energy expenditure in healthy neonates

OBJECTIVE: We investigated the value of resting energy expenditure (REE) in healthy neonates and evaluated the impact factors on REE. METHODS: One hundred eighty healthy neonates (95 boys and 85 girls) with birth weights above 2500 g were measured by indirect calorimetry, and the effect of birth weight evaluated. Measured and predicted REEs were compared, and the effects of sex and delivery method on REE were examined in 154 newborn infants with birth weights of approximately 2500 to 4000 g. RESULTS: Birth weight had a significant effect on REE. There was a negative relation between REE and birth weight (r = -0.289). The REEs of newborn infants weighing more than 4000 g were statistically lower than those of infants weighing 2500 to 4000 g (44.5 +/- 5.9 versus 48.3 +/- 6.1 kcal x kg(-1) x d(-1), P = 0.01). The measured and predicted REEs of 154 newborn infants were 48.3 +/- 6.1 and 54.1 +/- 1.1 kcal x kg(-1) x d(-1), respectively. There was a significant difference between the two values. Sex and delivery methods had no effect on REE in healthy neonates. CONCLUSIONS: The value from the predicted equation is not suitable for neonatal energy supplementation in clinical practice. The normal REE value for healthy neonates with birth weights of 2500 to 4000 g is 48.3 +/- 6.1 kcal x kg(-1) x d(-1).     

Nitrogen and Phosphorus Fertilizer Increases the Uptake of Soil Heavy Metal Pollutants by Plant Community

Soil heavy metal pollution is widespread around the world. Compared with hyperaccumulation plants, non-hyperaccumulator plant communities have many advantages in the remediation of heavy metals pollution in soil. The application of nitrogen (N) and phosphorus (P) is inexpensive and convenient, which can promote the growth of plant. N and P fertilizer might increase plant community remediation of heavy metal polluted soils. In our study, the effects of N and P fertilizer on remediation of soil Cd, Cu, Pb pollution by plant community were studied through a greenhouse experiment. Our results indicated that addition of N, P and N?+?P fertilizer increased plant community aboveground biomass. Simultaneously, addition of N and P fertilizer increased the accumulation of heavy metals in aboveground of the plant community and accelerated plants absorption soil heavy metals. Among them, N fertilizer had the best effect. Our results provide an inexpensive method for remediation heavy metal pollution of contaminated farmland, abandoned land and mine tailings, etc.

     

Phytotoxicity and phytoaccumulation of trivalent and hexavalent chromium in brake fern

A recently recognized hyperaccumulator plant, Chinese brake fern (Pteris vittata), has been found to extract very high concentration of arsenic from arsenic-contaminated soil. Chromium usually is a coexisting contaminant with arsenic in most contaminated soils. The potential application of ferns for phytoremediation of chromium(III)- and chromium(VI)-contaminated soils and their phytotoxicity to ferns has not been studied before. In this study, chromium distribution and phytotoxicity at the plant and cellular levels of brake ferns were studied using chemical analyses and scanning electron microscopy. The results show a higher phytotoxicity of Cr from Cr(VI)-contaminated soil to Chinese brake fern than from Cr(III)-contaminated soil. Phytotoxicity symptoms included significant decreases both in fresh biomass weight and relative water content (RWC), and also in leaf chlorosis during the late stage of growing. At higher concentrations (500 mg/kg Cr[VI] and 1,000 mg/kg Cr[III] addition), plants showed reduction in the number of palisade and spongy parenchyma cells in leaves. Compared with other plant species reported for phytoremediation of Cr(VI)-contaminated soil, brake fern took up and accumulated significant amounts of Cr (up to 1,145 mg/kg in shoots and 5,717 mg/kg in roots) and did not die immediately from phytotoxicity. Our study suggests that Chinese brake fern is a potential candidate for phytoremediation of Cr(VI)-contaminated soils, even though plants showed severe phytotoxic symptoms at higher soil Cr concentrations.     

Impact of the Combined Application of Biochar and Compost on Mine Soil Quality and Growth of Lady’s Finger (Abelmoschus esculentus)

Amelioration of mine soil is challenging because of the lack of biologically active organic matter. The study was aimed to recycle yard waste into compost and biochar and to use them to reclaim mine soil. Biochar prepared at 350 °C showed the highest stable organic matter yield index and was used for the experiments. Lady’s finger was grown on mine soil amended with biochar (1%–5%), compost (2%–10%), and biochar-compost mixtures (2%–10%). Mine soil pH increased in all treatments. Mine soil dehydrogenase activity (42%–224%), microbial biomass carbon (4%–257%), and hydrolase activity (3%–230%) increased by combined application of biochar and compost. Lady’s finger plant height, biomass, and fruit yield were superior in biochar–compost mixtures compared to biochar and compost alone treatment. Thus the use of compost along with biochar could be recommended for reclamation of mine soil.

     

Plant toxicity testing to derive ecological soil screening levels for cobalt and nickel

Phytotoxicity tests were performed to set ecological soil screening levels for cobalt (Co) and nickel (Ni) following the American Society for Testing and Materials international E1963-98 Standard Guide for Conducting Terrestrial Plant Toxicity Tests. Two soils (a modified artificial soil mixed with 5% organic matter, pH 5.01, and a native riverine sandy soil with 0.1% organic matter, pH 6.3) were treated with cobalt(II) chloride or nickel chloride and allowed to age for four weeks before initiating tests. Alfalfa, barley, radish, perennial rye, and brassica were used to determine the appropriate range of concentrations and to select the most sensitive plant species for definitive tests. The tests were designed to have one to three test concentrations below the 20% effects concentration (EC20), and five to six test concentrations above the EC20. Definitive tests for each chemical used two soil matrices, three plant species, and replicates at 10 nominal concentrations, including negative control. Soil chemical concentrations were determined before planting and on completion of the phytotoxicity tests. Threshold responses interpreted as the EC20 for each species endpoint were calculated from regression analyses. The geometric mean of the EC20 values (excluding emergence, mortality, and nodule numbers) for each species resulted in values of 30.6 mg/kg for Co and 27.9 mg/kg for Ni.     

Bioavailability and microbial adaptation to elevated levels of uranium in an acid, organic topsoil forming on an old mine spoil

An old mine spoil at a 19th-century mining site with considerable residues of uranium (400-800 mg U/kg) was investigated with respect to U concentrations in soil and plants and tolerance to U in the soil microbial community in order to describe the bioavailability of U. Measurements of soil fractions representing water-soluble U, easily exchangeable U, and U bound to humified organic matter showed that all fractions contained elevated concentrations of U. Plant U concentrations were only 10 times higher at the mine spoil site compared to the reference site (3 mg U/kg vs 0.3 mg U/kg), while the most easily available soil fractions contained 0.18 to 0.86 mg U/kg soil at the mine spoil. An ecotoxicity bioassay using incorporation of [3H]thymidine into the indigenous microbial communities of the two soils in the presence of increasing U concentrations showed that microorganisms at the mining site were sensitive to U but also that they had acquired a substantial tolerance toward U (EC50, the effective concentration reducing activity by 50% of UO2-citrate was approximately 120 microM as compared to 30 microM in the reference soil). In the assay, more than 40% of the microbial activity was maintained in the presence of 1 mM UO2-citrate versus 3% in the reference soil. We conclude that U-enriched mining waste can contain sufficiently elevated concentrations of bioavailable U to affect indigenous microorganisms and that bioavailable U imposes a selection pressure that favors the development of a highly uranium-tolerant microbial community, while plant uptake of U remains low.     

Modeling the toxicity of copper and zinc salts to wheat in 14 soils

Interest is mounting in developing and utilizing soil-specific soil quality guidelines. This requires quantifying the effects that soil physicochemical properties have on various ecotoxicological endpoints, including phytotoxicity. To this end, 14 agricultural soils from Australia with differing soil properties were spiked with copper (Cu) and zinc (Zn) salts and used to conduct 21-d plant growth inhibition tests using wheat (Triticum aestivum L.) in pot trials. The toxicity of Cu and Zn was similar with 10% effect concentration (EC10) values ranging from 110 to 945 and from 235 to 965 mg/kg, respectively, while the corresponding median effect concentration (EC50) values ranged from 240 to 1,405 and 470 to 1,745 mg/kg, respectively. Copper toxicity values (EC10, EC20, and EC50) were best modeled by the logarithm of cation exchange capacity (CEC) and either soil pH or electrical conductivity. Zinc EC50 and EC20 values were best modeled using the logarithm of CEC, while the EC10 data were best modeled using soil pH and the logarithm of organic carbon. These models generally estimated toxicity within a factor of two of the measured values.