Application of fish index of biological integrity (FIBI) in the Sanmenxia Wetland with water quality implications

Long-term changes of fish biotic integrity in the Sanmenxia Wetland,North China,since the 1950 s were assessed using the fish index of biological integrity（FIBI）. The water and sediment quality was evaluated by the water quality index（WQI） and sediment pollution index（SPI）. The results showed that FIBI continuously decreased from 46 to 20 during the past 5 decades,which indicated that the fish community state shifted from fair to very poor conditions,and damming by itself did not affect the fish biotic integrity. At the same time,WQI fell from 83 to 44.1,and SPI increased from 0.99 to 2.14 since the 1960 s,resulting from fast regional socio-economic development and insufficient wastewater treatment. Correlation analysis suggested that water quality significantly affected biotic integrity（r = 0.867,p 〈 0.05） through direct effects on the fish community. As a representative example of many wetlands in North China,our study clearly demonstrated that the biological integrity was degraded,induced both by water quality deterioration and sediment pollution,further driven by the contradiction between rapid development of regional economy and lagging development of sewage treatment facilities,which were thought to be the main factor responsible for the degradation of biological integrity.     

电镀厂周边环境中重金属分布特征及人体健康暴露风险评价

以广州市白云区两电镀厂为研究对象,采集电镀厂车间废气和周围空气及土壤样品,分析了样品中重金属(包括Cd、Cr、Cu、Ni、Pb、Zn和类重金属As、Hg)含量分布,分别应用地累积指数(Igeo)和US EPA的RAGS风险评估模型,对土壤中重金属污染程度、空气和土壤中重金属人体健康风险进行评价.结果表明,车间废气中Hg和Pb,空气中Cr分别高于相应标准限值,土壤中Cd、Hg和Zn达到中等污染程度.土壤和空气中重金属暴露的非致癌风险指数HQ和HI均1,非致癌健康风险可忽略.土壤中As和Cr的致癌风险10-4,高于最大可接受风险水平,CRCr对TCR贡献率81%.空气中Cr和Ni的致癌风险CR和TCR在10-6~10-4,存在致癌风险可能但低于最大可接受风险水平.土壤中重金属对儿童暴露的CR明显高于成人,而空气中重金属对成人暴露的CR值明显较高.相关分析表明土壤中重金属与废气中重金属含量密切相关,主成分分析表明土壤中达到中等污染的重金属来源可能不同于其它重金属.     

Determination and Evaluation of Cadmium, Copper, Nickel, and Zinc in Agricultural Soils of Western Macedonia, Greece

The objective of this study was to determine the levels of major phytotoxic metals―including cadmium (Cd), copper (Cu), nickel (Ni), and zinc (Zn)―in agricultural soils of Western Macedonia, Greece. We also wanted to determine the possible relationships among elements and between soil properties and elemental concentrations. Surface soil samples, n = 570, were collected and analyzed. The results of the elemental analysis showed that the mean metal concentrations were consistent with reported typical concentrations found in Greek agricultural soils in the cases of Zn and Cu. Cd exhibited lower and Ni higher mean concentrations than the typical levels reported in the literature. Metal concentrations in the majority of the examined samples (>69%) were found to be higher than the respective critical plant-deficiency levels. However, only 0.4% and 0.2% of the analyzed soil samples, respectively, exhibited Cd and Ni concentrations higher than the levels that cause plant toxicity, as referenced by other investigators. These results suggest that the soils studied can be considered as unpolluted with respect to the examined food-chain metal contaminants. However, the levels of the metal concentrations in some of the soil samples, and the low correlation of the metals with soil properties, suggest an anthropogenic rather that lithogenic origin.     

生活垃圾焚烧飞灰重金属在浸出柱中的浸出规律

通过浸出柱实验,研究生活垃圾焚烧飞灰中重金属的动态浸出规律.结果表明,浸出液中各种重金属的质量浓度均随浸取剂与飞灰比值(L/S)增大而减小,并在L/S＞2后趋于稳定.除Pb外,浸出质量浓度均低于污水综合排放标准(GB 8978-1996)限值.对比原灰与浸出残留物重金属多级提取结果表明,飞灰的重金属在浸出柱实验中释放能力由强到弱依次为:Cd、Ni、Cu、Pb、Zn和Cr.受浸取剂pH值和固液接触方式影响,浸出柱重金属累计浸出量都小于国家标准(GB 5086.2-1997)浸出量(Cd除外),尤其Cr、Hg和Pb的浸出柱累计浸出量分别是国标浸出量的23.25%、1.29%和14.29%     

垃圾焚烧飞灰基本性质的研究

分析了几种焚烧飞灰的基本性质,讨论了燃烧过程中可能影响飞灰中重金属分布的因素,研究表明:焚烧飞灰结构复杂性和性质多变,其主要的化学组成为Cl、Ca、K、Na、Si、Al、O等,主要的重金属为Zn、Pb、Cr、Cu等;飞灰多以不规则的无定形态和多晶聚合体的结构存在,浸出毒性一般超过危险废物鉴别标准;重金属主要以气溶胶小颗粒和富集于飞灰颗粒表面的形式存在于飞灰中.焚烧厂和焚烧时间的变化对于飞灰性质有较大影响,几种飞灰的Cl含量范围为6.93%～29.18%,SiO₂为4.48%～24.84%;浸出毒性则在0～163.10mg·L^-1(Pb)、0.049～164.90mg·L^-1(Zn)之间变化.     

Geochemistry of leachates from the El Fraile sulfide tailings piles in Taxco, Guerrero, southern Mexico

Leachates from the El Fraile tailings impoundment (Taxco, Mexico) were monitored every 2 months from October 2001 to August 2002 to assess the geochemical characteristics. These leachates are of interest because they are sometimes used as alternative sources of domestic water. Alternatively, they drain into the Cacalotenango creek and may represent a major source of metal contamination of surface water and sediments. Most El Fraile leachates show characteristics of Ca–SO₄, (Ca+Mg)–SO₄, Mg–SO₄ and Ca–(SO₄+HCO₃) water types and are near-neutral (pH=6.3–7.7). Some acid leachates are generated by the interaction of meteoric water with tailings during rainfall events (pH=2.4–2.5). These contain variable levels of SO₄ ²⁻ (280–29,500 mg l⁻¹) and As (<0.01–12.0 mg l⁻¹) as well as Fe (0.025–2352 mg l⁻¹), Mn (0.1–732 mg l⁻¹), Zn (<0.025–1465 mg l⁻¹) and Pb (<0.01–0.351 mg l⁻¹). Most samples show the highest metal enrichment during the dry seasons. Leachates used as domestic water typically exceed the Mexican Drinking Water Guidelines for sulfate, hardness, Fe, Mn, Pb and As, while acidic leachates exceed the Mexican Guidelines for Industrial Discharge Waters for pH, Cu, Cd and As. Speciation shows that in near-neutral solutions, metals exist mainly as free ions, sulfates and bicarbonates, while in acidic leachates they are present as sulfates and free ions. Arsenic appears as As^(V) in all samples. Thermodynamic and mineralogical evidence indicates that precipitation of Fe oxides and oxyhydroxides, clay minerals and jarosite as well as sorption by these minerals are the main processes controlling leachate chemistry. These processes occur mainly after neutralization by interaction with bedrock and equilibration with atmospheric oxygen.     

Distribution and mobility of metals in agricultural soils near a copper smelter in South China

The distribution and mobility of heavy metals in the paddy soils surrounding a copper smelting plant in south China was investigated. We assessed the degree of metal contamination using an index of geoaccumulation. The metals were divided into two groups: (1) Cu, Zn, Pb and Cd, whose concentrations were heavily affected by anthropogenic inputs, and (2) Ni, Co and Cr, which were mainly of geochemical origin. Concentrations of Cu, Cd, Zn, and Pb in the polluted soils were higher than the Chinese soil quality criteria. The chemical partitioning patterns of Pb, Zn and Cu indicated that Pb was largely associated with the residual and NH₂OH HCl extractable fractions. In contrast, Cd was predominantly associated with the MgCl₂ extractable fraction. A large proportion of Cu was bound to the acidic H₂O₂ extractable fractions, while Zn was predominantly found in the residual phase. The fraction of mobile species, which potentially is the most harmful to the environment, was found to be elevated compared to unpolluted soils in which heavy metals are more strongly bound to the matrix. The mobility of the metals was studied by water extraction using a modification of Tessier’s procedure, and the order of mobility was Zn > Cd > Cu  > Pb.     

Comparison of trace element concentrations in livers of diseased, emaciated and non-diseased southern sea otters from the California coast

Infectious diseases have been implicated as a cause of high rates of adult mortality in southern sea otters. Exposure to environmental contaminants can compromise the immuno-competence of animals, predisposing them to infectious diseases. In addition to organic pollutants, certain trace elements can modulate the immune system in marine mammals. Nevertheless, reports of occurrence of trace elements, including toxic heavy metals, in sea otters are not available. In this study, concentrations of 20 trace elements (V, Cr, Mn, Co, Cu, Zn, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb, and Bi) were measured in livers of southern sea otters found dead along the central California coast (n = 80) from 1992 to 2002. Hepatic concentrations of trace elements were compared among sea otters that died from infectious diseases (n = 27), those that died from non-infectious causes (n = 26), and otters that died in emaciated condition with no evidence of another cause of death (n = 27). Concentrations of essential elements in sea otters varied within an order of magnitude, whereas concentrations of non-essential elements varied by two to five orders of magnitude. Hepatic concentrations of Cu and Cd were 10- to 100-fold higher in the sea otters in this study than concentrations reported for any other marine mammal species. Concentrations of Mn, Co, Zn, and Cd were elevated in the diseased and emaciated sea otters relative to the non-diseased sea otters. Elevated concentrations of essential elements such as Mn, Zn, and Co in the diseased/emaciated sea otters suggest that induction of synthesis of metallothionein and superoxide dismutase (SOD) enzyme is occurring in these animals, as a means of protecting the cells from oxidative stress-related injuries. Trace element profiles in diseased and emaciated sea otters suggest that oxidative stress mediates the perturbation of essential-element concentrations. Elevated concentrations of toxic metals such as Cd, in addition to several other organic pollutants, may contribute to oxidative stress-meditated effects in sea otters.     

Bioaccumulation of Hg, Cu, and Zn in the Azores triple junction hydrothermal vent fields food web

In this work, mercury (Hg), copper (Cu) and zinc (Zn) concentrations and tissue distribution are determined in seven benthic invertebrates species (the key species) from the Mid Atlantic Ridge (MAR) hydrothermal vent fields. The samples were collected from three hydrothermal vent fields – Menez Gwen, 840 m; Lucky Strike, 1700 m and Rainbow, 2300 m – near the Azores Triple Junction. These fields are characterized by different depths, geological context and chemical composition of the hydrothermal fluid, particularly the metal content, which is reflected by the metal concentrations in the organisms. Indeed, our results show that organisms from Menez Gwen presented the highest Hg concentrations, while those from Lucky Strike and Rainbow were richer in Cu and Zn. The potential transfer of these metals through two trophic links are also evaluated and include (1) the mussel Bathymodiolus azoricus and the commensal worm Branchipolynoe seepensis, and (2) three different species of shrimps and the crab Segonzacia mesatlantica. No evidence of Hg biomagnification in either of the vent food chains is clearly observed but an increase in Hg accumulation from prey to predator in the crustacean food chain. The same pattern was observed for Cu and Zn, even though these metals are not known to be generally biomagnified in food chains.     

不同湿地植物凋落物对汞铊矿废弃物浸出酸性废水中重金属的吸附研究

研究了不同湿地植物(稻草(Oryza sativa L.)、风车草(Cyperus involucratus Rottb.)、芦竹(Arundo donax L.)、美人蕉(Canna indica L.)、水葱(Scirpus validus Vahl.)、香蒲(Typha orientalis C.Presl)和鸢...