WorldWideScience

Sample records for airborne toxic metals

  1. Risk assessment of inhalation exposure for airborne toxic metals using instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    In order to study the effects of air pollution, about 1,300 samples of airborne particulate matter (APM) were collected at suburban and industrial sites, in Daejeon, Korea from 1998 to 2006. The concentrations of carcinogenic (As and Cr) and non-carcinogenic metals (Al, Mn, and Zn) were determined by using instrumental neutron activation analysis (INAA). These long-term metal concentration data were applied to a risk assessment of inhalation exposure using Monte Carlo analysis (MCA). (author)

  2. Metal metabolism and toxicity

    International Nuclear Information System (INIS)

    This research focuses on the role of pregnancy and lactation in susceptibility to the toxic effects of cadmium and lead. Responses under investigation include lead-induced changes in pathways for vitamin D and calcium metabolism and cadmium-induced alterations in kidney function and skeletal structure. The second area focuses on the gastrointestinal absorption of plutonium and other actinide elements. Studies currently being conducted in nonhuman primates to develop a procedure to determine GI absorption values of uranium and plutonium that does not require sacrifice of the animal. 6 refs

  3. Pollution Characteristics and Health Risk Assessment of Airborne Heavy Metals Collected from Beijing Bus Stations

    OpenAIRE

    Xiaoxia Zheng; Wenji Zhao; Xing Yan; Tongtong Shu; Qiulin Xiong; Fantao Chen

    2015-01-01

    Airborne dust, which contains high levels of toxic metals, is recognized as one of the most harmful environment component. The purpose of this study was to evaluate heavy metals pollution in dustfall from bus stations in Beijing, and to perform a risk assessment analysis for adult passengers. The concentrations of Cd, Co, Cr, Cu, Mo, Ni, Pb, V and Zn were determined by inductively coupled plasma mass spectroscopy (ICP-MS). The spatial distribution, pollution level and potential health risk of...

  4. Biomonitoring of Toxic Compounds of Airborne Particulate Matter in Urban and Industriel Areas

    DEFF Research Database (Denmark)

    Klumpp, Andreas; Ro-Poulsen, Helge

    The toxicity and ecotoxicity of airborne particulate matter is determined by its physical features, but also by its chemical composition. The standardised exposure of accumulative bioindicator plants is suggested as an efficient and reliable tool to assess and monitor effects of particulate matter...... on man and environment. Two widely applied biomonitoring procedures, namely the standardised ryegrass exposure for monitoring of trace metals, and the standardised exposure of curly kale for monitoring of PAH compounds, is presented taking examples from a Europe-wide biomonitoring study conducted in...... these methods in environmental monitoring programmes are made...

  5. SIZE DISTRIBUTION AND RATE OF PRODUCTION OF AIRBORNE PARTICULATE MATTER GENERATED DURING METAL CUTTING

    International Nuclear Information System (INIS)

    During deactivation and decommissioning activities, thermal cutting tools, such as plasma torch, laser, and gasoline torch, are used to cut metals. These activities generate fumes, smoke and particulates. These airborne species of matter, called aerosols, may be inhaled if suitable respiratory protection is not used. Inhalation of the airborne metallic aerosols has been reported to cause ill health effects, such as acute respiratory syndrome and chromosome damage in lymphocytes. In the nuclear industry, metals may be contaminated with radioactive materials. Cutting these metals, as in size reduction of gloveboxes and tanks, produces high concentrations of airborne transuranic particles. Particles of the respirable size range (size < 10 microm) deposit in various compartments of the respiratory tract, the fraction and the site in the respiratory tract depending on the size of the particles. The dose delivered to the respiratory tract depends on the size distribution of the airborne particulates (aerosols) and their concentration and radioactivity/toxicity. The concentration of airborne particulate matter in an environment is dependent upon the rate of their production and the ventilation rate. Thus, measuring aerosol size distribution and generation rate is important for (1) the assessment of inhalation exposures of workers, (2) the selection of respiratory protection equipment, and (3) the design of appropriate filtration systems. Size distribution of the aerosols generated during cutting of different metals by plasma torch was measured. Cutting rates of different metals, rate of generation of respirable mass, as well as the fraction of the released kerf that become respirable were determined. This report presents results of these studies. Measurements of the particles generated during cutting of metal plates with a plasma arc torch revealed the presence of particles with mass median aerodynamic diameters of particles close to 0.2 micro

  6. Toxicity to chicken embryos of organic extracts from airborne particulates separated into five sizes

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, H.

    1988-07-01

    The chicken embryo assay has been used for research on the toxicity of complex extracts derived from different environmental sources, as well as of individual compounds. However, only a few studies have been made on the toxicological effects of extracts derived from airborne particulate matter in chicken embryo. These studies showed that the toxic effect was due to the polycyclic aromatic hydrocarbons (PAHs) in the particles, although their structure and quantity were the factors determining the extent of the toxicity. Airborne particulate matter is composed of particles of different sizes, which can be separated into five classes according to their size by an Andersen high-volume sampler. Each class contained many kinds of compounds such as PAHs. In this study, airborne particulate matter was extracted according to particle size, the extracts analyzed for PAHs, and tested for embryotoxicity.

  7. Toxic heavy metals: materials cycle optimization.

    OpenAIRE

    Ayres, R U

    1992-01-01

    Long-term ecological sustainability is incompatible with an open materials cycle. The toxic heavy metals (arsenic, cadmium, chromium, copper, lead, mercury, silver, uranium/plutonium, zinc) exemplify the problem. These metals are being mobilized and dispersed into the environment by industrial activity at a rate far higher than by natural processes. Apart from losses to the environment resulting from mine wastes and primary processing, many of these metals are utilized in products that are in...

  8. Metal oxide nanoparticles with low toxicity.

    Science.gov (United States)

    Ng, Alan Man Ching; Guo, Mu Yao; Leung, Yu Hang; Chan, Charis M N; Wong, Stella W Y; Yung, Mana M N; Ma, Angel P Y; Djurišić, Aleksandra B; Leung, Frederick C C; Leung, Kenneth M Y; Chan, Wai Kin; Lee, Hung Kay

    2015-10-01

    A number of different nanomaterials produced and incorporated into various products are rising. However, their environmental hazards are frequently unknown. Here we consider three different metal oxide compounds (SnO2, In2O3, and Al2O3), which have not been extensively studied and are expected to have low toxicity. This study aimed to comprehensively characterize the physicochemical properties of these nanomaterials and investigate their toxicity on bacteria (Escherichia coli) under UV illumination and in the dark, as well as on a marine diatom (Skeletonema costatum) under ambient illumination/dark (16-8h) cycles. The material properties responsible for their low toxicity have been identified based on comprehensive experimental characterizations and comparison to a metal oxide exhibiting significant toxicity under illumination (anatase TiO2). The metal oxide materials investigated exhibited significant difference in surface properties and interaction with the living organisms. In order for a material to exhibit significant toxicity, it needs to be able to both form a stable suspension in the culture medium and to interact with the cell walls of the test organism. Our results indicated that the observed low toxicities of the three nanomaterials could be attributed to the limited interaction between the nanoparticles and cell walls of the test organisms. This could occur either due to the lack of significant attachment between nanoparticles and cell walls, or due to their tendency to aggregate in solution. PMID:26143160

  9. Behavior as a sentry of metal toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, B.

    1978-01-01

    Many of the toxic properties of metals are expressed as behavioral aberrations. Some of these arise from direct actions on the central nervous system. Others arise from primary events elsewhere, but still influence behavior. Toxicity may be expressed either as objectively measurable phenomena, such as ataxia, or as subjective complaints, such as depression. In neither instance is clinical medicine equipped to provide assessments of subtle, early indices of toxicity. Reviewers of visual disturbances, paresthesia, and mental retardation exemplify the potential contribution of psychology to the toxicology of metals. Behavior and nervous system functions act as sensitive mirrors of metal toxicity. Sensitivity is the prime aim in environmental health assessments. Early detection of adverse effects, before they progress to irreversibility, underlies the strategy for optimal health protection. Some of the toxic actions of metals originate in direct nervous system dysfunction. Others may reflect disturbances of systems less directly linked to behavior than the central nervous system. But behavior, because it expresses the integrated functioning of the organism, can indicate flaws in states and processes outside the nervous system.

  10. Removal of soluble toxic metals from water

    International Nuclear Information System (INIS)

    The removal of selected, soluble toxic metals from aqueous solutions has been accomplished using a combination of chemical treatment and ultrafiltration. The process has been evaluated at the bench-scale and is undergoing pilot-scale testing. Removal efficiencies in excess of 95-99% have been realized. The test program at the bench-scale investigated the limitations and established the optimum range of operating parameters for the process, while the tests conducted with the pilot-scale process equipment are providing information on longer-term process efficiencies, effective processing rates, and fouling potential of the membranes. With the typically found average concentrations of the toxic metals in groundwaters at Superfund sites used as the feed solution, the process has decreased levels up to 100-fold or more. Experiments were also conducted with concentrated solutions to determine their release from silica-based matrices. The solidified wastes were subjected to EP Toxicity test procedures and met the criteria successfully. The final phase of the program involving a field demonstration at a uranium tailings site will be outlined

  11. A new approach for determination of soluble trace metal fractions in airborne particulate matter using a dynamic extraction procedure coupled to ICP-AES

    International Nuclear Information System (INIS)

    Complete text of publication follows. The current interest in atmospheric particulate matter (PM) is mainly due to its effect on human health. A fraction that is associated with several adverse health effects - including cancer - is the metallic portion. For this reason, a great deal of research has focused on the metal composition of airborne particulate matter. Until now in most studies total elemental concentrations were determined. However, toxic effects of trace metals in airborne PM are only expected if the metals are biologically available. Thus for risk assessment detailed knowledge about the solubility of the investigated metals is required since bioavailability depends thereon. Recently various extraction schemes have been developed for batch-wise fractionation of various metals in airborne particulate matter. Although these batch-wise liquid/solid extraction methods have gained widespread acceptance in literature the eco-toxicological relevance of the information provided with these techniques is questionable, since naturally occurring processes occur always under dynamic conditions. In this study a procedure for the sequential extraction of airborne particulate matter with various leaching solutions and the subsequent on-line ICP-AES measurement of selected trace metals in the derived extracts is presented. For analysis several punches of the filter substrate were packed into indigenously developed micro-columns and treated successively with the different extraction solutions. Evaluation of the derived elution profiles provided information about the kinetics of the extraction process and allowed differentiation between individual soluble fractions.

  12. Compositions and methods for removal of toxic metals and radionuclides

    Science.gov (United States)

    Cuero, Raul G. (Inventor); McKay, David S. (Inventor)

    2007-01-01

    The present invention relates to compositions and methods for the removal of toxic metals or radionuclides from source materials. Toxic metals may be removed from source materials using a clay, such as attapulgite or highly cationic bentonite, and chitin or chitosan. Toxic metals may also be removed using volcanic ash alone or in combination with chitin or chitosan. Radionuclides may be removed using volcanic ash alone or in combination with chitin or chitosan.

  13. Characterizing toxicity of metal-contaminated sediments from mining areas

    International Nuclear Information System (INIS)

    Highlights: • We review methods for testing toxicity of sediments affected by metals. • Toxicity testing provides site-specific assessment of impacts on resident biota. • Goals are to document extent of toxicity and associations with metal exposure. • Need to characterize bioavailability of metals in sediment and pore water. • Toxicity data is basis for guidelines used to predict hazards of metal toxicity. - Abstract: This paper reviews methods for testing the toxicity of metals associated with freshwater sediments, linking toxic effects with metal exposure and bioavailability, and developing sediment quality guidelines. The most broadly applicable approach for characterizing metal toxicity is whole-sediment toxicity testing, which attempts to simulate natural exposure conditions in the laboratory. Standard methods for whole-sediment testing can be adapted to test a wide variety of taxa. Chronic sediment tests that characterize effects on multiple endpoints (e.g., survival, growth, and reproduction) can be highly sensitive indicators of adverse effects on resident invertebrate taxa. Methods for testing of aqueous phases (pore water, overlying water, or elutriates) are used less frequently. Analysis of sediment toxicity data focuses on statistical comparisons between responses in sediments from the study area and responses in one or more uncontaminated reference sediments. For large or complex study areas, a greater number of reference sediments is recommended to reliably define the normal range of responses in uncontaminated sediments – the ‘reference envelope’. Data on metal concentrations and effects on test organisms across a gradient of contamination may allow development of concentration-response models, which estimate metal concentrations associated with specified levels of toxic effects (e.g. 20% effect concentration or EC20). Comparisons of toxic effects in laboratory tests with measures of impacts on resident benthic invertebrate

  14. Insights into the superhydrophobicity of metallic surfaces prepared by electrodeposition involving spontaneous adsorption of airborne hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Peng; Cao, Ling; Zhao, Wei; Xia, Yue; Huang, Wei; Li, Zelin, E-mail: lizelin@hunnu.edu.cn

    2015-01-01

    Graphical abstract: - Highlights: • Several superhydrophobic metallic surfaces were fabricated by fast electrodeposition. • Both micro/nanostructures and adsorption of airborne hydrocarbons make contributions. • XPS analyses confirm presence of airborne hydrocarbons on these metallic surfaces. • The adsorption of airborne hydrocarbons on the clean metal Au surface was very quick. • UV-O{sub 3} treatment oxidized the hydrocarbons to hydrophilic oxygen-containing organics. - Abstract: Electrochemical fabrication of micro/nanostructured metallic surfaces with superhydrophobicity has recently aroused great attention. However, the origin still remains unclear why smooth hydrophilic metal surfaces become superhydrophobic by making micro/nanostructures without additional surface modifications. In this work, several superhydrophobic micro/nanostructured metal surfaces were prepared by a facile one-step electrodeposition process, including non-noble and noble metals such as copper, nickel, cadmium, zinc, gold, and palladium with (e.g. Cu) or without (e.g. Au) surface oxide films. We demonstrated by SEM and XPS that both hierarchical micro/nanostructures and spontaneous adsorption of airborne hydrocarbons endowed these surfaces with excellent superhydrophobicity. We revealed by XPS that the adsorption of airborne hydrocarbons at the Ar{sup +}-etched clean Au surface was rather quick, such that organic contamination can hardly be prevented in practical operation of surface wetting investigation. We also confirmed by XPS that ultraviolet-O{sub 3} treatment of the superhydrophobic metal surfaces did not remove the adsorbed hydrocarbons completely, but mainly oxidized them into hydrophilic oxygen-containing organic substances. We hope our findings here shed new light on deeper understanding of superhydrophobicity for micro/nanostructured metal surfaces with and without surface oxide films.

  15. Role of Calcium Channels in Heavy Metal Toxicity

    OpenAIRE

    Carla Marchetti

    2013-01-01

    Cellular membranes are basically impermeable to ions and have developed specific pathways (channels, transporters or pumps) to facilitate metal translocation. These physiological carriers are not ideally selective and their specificity spectrum may include xenobiotic species, such as toxic metals whose availability in the environment has increased enormously in industrial times. I have studied the pathways of influx of two toxic metals, lead (Pb) and cadmium (Cd) in mammalian cells. Both meta...

  16. Toxic metals in aquatic ecosystems: a microbiological perspective.

    Science.gov (United States)

    Ford, T; Ryan, D

    1995-02-01

    Microbe-metal interactions in aquatic environments and their exact role in transport and transformations of toxic metals are poorly understood. This paper will briefly review our understanding of these interactions. Ongoing research in Lake Chapala, Mexico, the major water source for the City of Guadalajara, provides an opportunity to study the microbiological aspects of metal-cycling in the water column. Constant resuspension of sediments provides a microbiologically rich aggregate-based system. Data indicate that toxic metals are concentrated on aggregate material and bioaccumulate in the food chain. A provisional model is presented for involvement of microbial aggregates in metal-cycling in Lake Chapala. PMID:7621793

  17. A Prospective Analysis of Airborne Metal Exposures and Risk of Parkinson Disease in the Nurses’ Health Study Cohort

    Science.gov (United States)

    Fitzgerald, Kathryn; Roberts, Andrea L.; Hart, Jaime E.; Weisskopf, Marc G.; Schwarzschild, Michael A.; Ascherio, Alberto; Laden, Francine

    2014-01-01

    Background: Exposure to metals has been implicated in the pathogenesis of Parkinson disease (PD). Objectives: We sought to examine in a large prospective study of female nurses whether exposure to airborne metals was associated with risk of PD. Methods: We linked the U.S. Environmental Protection Agency (EPA)’s Air Toxics tract-level data with the Nurses’ Health Study, a prospective cohort of female nurses. Over the course of 18 years of follow-up from 1990 through 2008, we identified 425 incident cases of PD. We examined the association of risk of PD with the following metals that were part of the first U.S. EPA collections in 1990, 1996, and 1999: arsenic, antimony, cadmium, chromium, lead, manganese, mercury, and nickel. To estimate hazard ratios (HRs) and 95% CIs, we used the Cox proportional hazards model, adjusting for age, smoking, and population density. Results: In adjusted models, the HR for the highest compared with the lowest quartile of each metal ranged from 0.78 (95% CI: 0.59, 1.04) for chromium to 1.33 (95% CI: 0.98, 1.79) for mercury. Conclusions: Overall, we found limited evidence for the association between adulthood ambient exposure to metals and risk of PD. The results for mercury need to be confirmed in future studies. Citation: Palacios N, Fitzgerald K, Roberts AL, Hart JE, Weisskopf MG, Schwarzschild MA, Ascherio A, Laden F. 2014. A prospective analysis of airborne metal exposures and risk of Parkinson disease in the Nurses’ Health Study Cohort. Environ Health Perspect 122:933–938; http://dx.doi.org/10.1289/ehp.1307218 PMID:24905870

  18. Biokinetics and tolerance development of toxic metals in Daphnia magna.

    Science.gov (United States)

    Tsui, Martin Tsz-Ki; Wang, Wen-Xiong

    2007-05-01

    Daphnia magna is widespread in many freshwater systems of temperate regions and frequently is used to test metal toxicity. Recently, studies have been performed to determine metal biokinetics and development of tolerance in this important zooplankton species. In the present paper, we review the recent progress in these areas and suggest possible directions for future studies. Substantial differences exist in aqueous uptake, dietary assimilation, and elimination of several metals (Cd, Se, Zn, Ag, Hg, and MeHg) by D. magna. The routes of uptake are metal-specific, with Se and MeHg being accumulated predominantly through diet. All metals except Ag can be biomagnified from algae to D. magna, providing that metal concentrations in algae and algal food density are relatively low. Methylmercury is biomagnified in all situations. As a route for metal elimination in D. magna, maternal transfer is especially important for Se, Zn, and MeHg. On the other hand, the effect of single-generation exposure to metals on D. magna is very different from multigeneration exposure, which often results in a significantly higher metal tolerance. Moreover, D. magna easily loses metal tolerance developed through long-term exposure. Recovery from metal stress can temporarily increase the sensitivity of D. magna to metal toxicity. Finally, metallothionein-like protein is responsible for minimizing metal toxicity in D. magna. The results inferred from these studies can be extrapolated to other aquatic invertebrates as well as to other pollutants in the aquatic environment. PMID:17521151

  19. Principles for prevention of toxic effects from metals

    DEFF Research Database (Denmark)

    Landrigan, Philip J.; Kotelchuk, David; Grandjean, Philippe

    2007-01-01

    Toxic Effects of Metals Aluminum Antimony Arsenic Barium Beryllium Bismuth Cadmium Chromium Cobalt Copper Gallium and Semiconductor Compounds Germanium Indium Iron Lead Manganese Mercury Molybdenum Nickel Palladium Platinum Selenium Silver Tellurium Thallium Tin Titanium Tungsten Uranium Vanadium Zinc...

  20. Semen quality and heavy metal and pesticides toxicity

    OpenAIRE

    Lidia Mínguez-Alarcón; Jaime Mendiola Olivares; Alberto Manuel Torres-Cantero

    2014-01-01

    Male reproductive function has deteriorated significantly in the past 50 years and this change could be related to an exposure to occupational and environmental pollutants and toxicants. The purpose of this paper is to summarize the negative impact of human exposure to heavy metals and pesticides on the male reproductive function. Most pesticides and heavy metals are considered reproductive toxicants and may adversely harm the male reproductive system due to their disrupting effect on the hyp...

  1. Heavy metals, PAHs and toxicity in stormwater wet detention ponds

    DEFF Research Database (Denmark)

    Wium-Andersen, Tove; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild;

    2011-01-01

    Concentrations of 6 different heavy metals and total Polycyclic Aromatic Hydrocarbons (PAH) were determined in stormwater runoff and in the pond water of two Danish wet detention ponds. The pond water samples were analyzed for toxic effects, using the algae Selenastrum capricornutum as a test...... organism. Stormwater and pond water from a catchment with light industry showed high levels of heavy metals, especially zinc and copper. The pond water showed high toxic effects and copper were found to be the main toxicant. Additionally, a large part of the copper was suspected to be complex bound...

  2. Microchip Analysis of Toxic Metal Ions in Support of DOE's EMSP

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Greg E.; Lu, Qin; Deng, Gang

    2003-09-10

    The DoE currently has the daunting task of deactivating 7,000 contaminated buildings and decommissioning 900 contaminated buildings that remain from the United States' involvement in nuclear weapons development over the last 50 years. The Environmental Management team has highlighted the need for revolutionizing technologies capable of improving characterization, monitoring and certification of contaminated equipment and facilities with emphasis on real time characterization in the field. We will discuss our efforts to develop a portable, compact microchip capillary electrophoresis unit for rapid characterization and certification of ppb levels of surface and airborne toxic metal contaminants found or originating from scrap metal and building materials in real time within the field.

  3. Beneficial effect of sesame oil on heavy metal toxicity.

    Science.gov (United States)

    Chandrasekaran, Victor Raj Mohan; Hsu, Dur-Zong; Liu, Ming-Yie

    2014-02-01

    Heavy metals become toxic when they are not metabolized by the body and accumulate in the soft tissue. Chelation therapy is mainly for the management of heavy metal-induced toxicity; however, it usually causes adverse effects or completely blocks the vital function of the particular metal chelated. Much attention has been paid to the development of chelating agents from natural sources to counteract lead- and iron-induced hepatic and renal damage. Sesame oil (a natural edible oil) and sesamol (an active antioxidant) are potently beneficial for treating lead- and iron-induced hepatic and renal toxicity and have no adverse effects. Sesame oil and sesamol significantly inhibit iron-induced lipid peroxidation by inhibiting the xanthine oxidase, nitric oxide, superoxide anion, and hydroxyl radical generation. In addition, sesame oil is a potent inhibitor of proinflammatory mediators, and it attenuates lead-induced hepatic damage by inhibiting nitric oxide, tumor necrosis factor-α, and interleukin-1β levels. Because metal chelating therapy is associated with adverse effects, treating heavy metal toxicity in addition with sesame oil and sesamol may be better alternatives. This review deals with the possible use and beneficial effects of sesame oil and sesamol during heavy metal toxicity treatment. PMID:23744838

  4. Toxicity of and metals in coal combustion ash leachate

    International Nuclear Information System (INIS)

    Land disposal of coal combustion ash can have a potential impact on the ecosystem due to the leaching of metals with increasing acidity of precipitation. The effect of pH on the concentration of metals leached from coal combustion ash was studied and the toxicity of the leachate measured. Bottom coal combustion ash was leached with hydrochloric acid (HCl) or acetic acid (CH3COOH) at pH 4,5,6 or 7. The toxicity of the aqueous leachates and concentrations of the metals (arsenic, cadmium, chromium, copper, iron, lead, nickel, silver and zinc) therein were measured using Microtox (Vibrio fischeri-EC50%) and atomic absorption spectrophotometry, respectively. Toxicity and metal concentrations of the leachates were highest when ash was leached with HCl at pH 4. Toxicity and metal concentrations of ash leached with CH3COOH were significantly lower compared with ash leached with HCl. A high correlation was observed between the toxicity and the metal concentrations in both the acid leachates

  5. Toxicity from Metals, Old Menaces and New Threats

    Directory of Open Access Journals (Sweden)

    Wayne Briner

    2010-12-01

    Full Text Available Metals make up the bulk of the periodic table and range from the very light (e.g., beryllium to the very heavy (e.g., the actinides. Metals are important constituents of life, drive economic activity and industry, but can also be a hazard to human health. The metals can be roughly divided into three groups. The first being those metals, such as iron and zinc, that are essential to human life and have a wide therapeutic dose range. The second group of metals, such as lead, mercury, and uranium, has no known biological role and are toxic even at low doses. The third group of metals, such as selenium and manganese, has a role in maintaining human health but has a very narrow dose range that, when exceeded, produces toxic effects. [...

  6. Anaerobic microbial transformations of uranium and toxic metals in wastes

    International Nuclear Information System (INIS)

    The effects of anaerobic microbial activity on the dissolution and immobilization of uranium and toxic metals from uranium processing wastes were investigated. The wastes contained As, Cd, Cr, Cu, Hg, Pb, Ni, U and Zn. A substantial quantity of the toxic metals associated with exchangeable, carbonate, and iron oxide fractions were solubilized by indirect action due to production of organic acid metabolites or by direct enzymatic action. Several of the solubilized metals were immobilized due to biosorption by bacterial biomass, reduction and precipitation, and redistribution to a more stable form with the minerals in the waste. Anaerobic bacterial treatment of wastes resulted in the removal of a large fraction of soluble non-toxic metals such as calcium and iron and also volume and mass reduction

  7. Toxic Metals in Aquatic Ecosystems: A Microbiological Perspective

    OpenAIRE

    Ryan, David P; Ford, Timothy

    1995-01-01

    Microbe-metal interactions in aquatic environments and their exact role in transport and transformations of toxic metals are poorly understood. This paper will briefly review our understanding of these interactions. Ongoing research in Lake Chapala, Mexico, the major water source for the City of Guadalajara, provides an opportunity to study the microbiological aspects of metal-cycling in the water column. Constant resuspension of sediments provides a microbiologically rich aggregate-based sys...

  8. Heavy Metal Bioaccumulation and Toxicity with Special Reference to Microalgae

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The bioaccumulation and toxicity of heavy metals were reviewed with special reference to microalgae, the key component of the food web in aquatic ecosystems. Heavy metals enter algal cells either by means of active transport or by endocytosis through chelating proteins and affect various physiological and biochemical processes of the algae. The toxicity primarily results from their binding to the sulphydryl groups in proteins or disrupting protein structure or displacing essential elements. Metals can break the oxidative balance of the algae, inducing antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and ascorbate peroxidase (APX). The amount of oxidized proteins and lipids in the algal cells thus indicates the severity of the stress. Algal tolerance to heavy metal is highly dependent upon the defense response against the probable oxidative damages. Production of binding factors and proteins, exclusion of metals from cells by ion-selective transporters and excretion or compartmentalization have been suggested with regard to reducing heavy metal toxicity. However, a comprehensive description on the mechanisms underlining metal toxicity of microalgae and gaining tolerance is yet to be elaborated.

  9. Accumulation rates of airborne heavy metals in wetlands

    Science.gov (United States)

    Souch, C.J.; Filippelli, G.M.; Dollar, N.; Perkins, S.; Mastalerz, Maria

    2002-01-01

    Accumulation rates of heavy metals (Cd, Cr, Cu, Mn, Pb, and Zn) retained in wetland sediments in northwest Indiana-downwind of the Chicago-Gary-Hammond industrial area-are quantified to assess anthropogenic influences on atmospheric fluxes. Metal concentrations for 22 sediment cores are determined by ICP-AES after ashing and strong acid extraction. Relations between organic content and metal concentrations at depth are used to separate natural and anthropogenic sources. Accumulation rates over the lifetime of the wetlands (???4500 years) have averaged 0.2 (Cd), 1.4 (Cu), 1.7 (Cr), 13.4 (Mn), 4.8 (Pb), and 18.7 (Zn) mg m-2 y-1. Rates for the last 100 years have increased on average by factors of 6 (Cd), 8 (Cu), 10 (Mn), 15 (Pb), and 30 (Zn), remaining effectively constant for Cr. Where the wetlands have been drained, metals have been lost from the sediments, owing to changes in organic content and local hydrochemistry (exposure to acidic rainfall). Sediment-based accumulation rates at the undrained sites are higher, though generally consistent, with measured and modeled atmospheric fluxes documented by short-term studies conducted over the last three decades. The fraction of the total metals in the wetlands estimated to be of anthropogenic origin ranges from approximately 3% for Cr, up to approximately 35% for Pb, and 70% for Zn. This historic legacy of contamination must be considered in land management decisions, particularly when wetlands are drained.

  10. Chlorine-heavy metals interaction on toxicity and metal accumulation

    International Nuclear Information System (INIS)

    The primary objectives of this study with rainbow trout (Salmo gairdneri) were: to determine whether acute toxic interaction of chlorine, nickel, and temperature is additive, synergistic, antagonistic, or if no interaction occurs; to provide a biological explanation of the mechanisms of the toxic interactions; and to develop a mortality model of the toxic interaction. Twenty chlorine-nickel toxicity tests and a bioaccumulation study, both with and without chlorine, were conducted to accomplish these objectives. Studies using 63Ni were conducted to monitor the effects of chlorine on nickel accumulation in the tissues of trout under conditions similar to those of multiple toxicant studies. The presence of 0.018 ppM TRC (total residual chlorine) increased nickel accumulation in tissues from fish exposed to chlorine and 63Ni. This may be due to an increase in the permeability of the gill to nickel during chlorine exposure. Chlorine and nickel had a synergistic toxic interaction. Mortality in these groups was significantly higher. Temperature did not influence toxicity as strongly

  11. Assessment of Metal Toxicity in Marine Ecosystems: Comparative Toxicity Potentials for Nine Cationic Metals in Coastal Seawater

    DEFF Research Database (Denmark)

    Dong, Yan; Rosenbaum, Ralph K.; Hauschild, Michael Zwicky

    2016-01-01

    ecotoxicity data and take account of metal speciation and bioavailability. CTPs were developed for nine cationic metals (Cd, Cr(III), Co, Cu(II), Fe(III), Mn, Ni, Pb and Zn) in 64 Large Marine Ecosystems (LMEs) covering all coastal waters in the world. The results showed that the CTP of a specific metal...... occurring in coastal seawaters, Fe acts not as a toxic agent but an essential nutrient and thus has CTPs of zero....

  12. Metal toxicity and the respiratory tract.

    Science.gov (United States)

    Nemery, B

    1990-02-01

    The type of lung disease caused by metal compounds depends on the nature of the offending agent, its physicochemical form, the dose, exposure conditions and host factors. The fumes or gaseous forms of several metals, e.g. cadmium (Cd), manganese (Mn), mercury (Hg), nickel carbonyl (Nl(CO)4, zinc chloride (ZnCl2), vanadium pentoxide (V2O5), may lead to acute chemical pneumonitis and pulmonary oedema or to acute tracheobronchitis. Metal fume fever, which may follow the inhalation of metal fumes e.g. zinc (Zn), copper (Cu) and many others, is a poorly understood influenza-like reaction, accompanied by an acute self-limiting neutrophil alveolitis. Chronic obstructive lung disease may result from occupational exposure to mineral dusts, including probably some metallic dusts, or from jobs involving the working of metal compounds, such as welding. Exposure to cadmium may lead to emphysema. Bronchial asthma may be caused by complex platinum salts, nickel, chromium or cobalt, presumably on the basis of allergic sensitization. The cause of asthma in aluminium workers is unknown. It is remarkable that asthma induced by nickel (Ni) or chromium (Cr) is apparently infrequent, considering their potency and frequent involvement as dermal sensitizers. Metallic dusts deposited in the lung may give rise to pulmonary fibrosis and functional impairment, depending on the fibrogenic potential of the agent and on poorly understood host factors. Inhalation of iron compounds causes siderosis, a pneumoconiosis with little or no fibrosis. Hard metal lung disease is a fibrosis characterized by desquamative and giant cell interstitial pneumonitis and is probably caused by cobalt, since a similar disease has been observed in workers exposed to cobalt in the absence of tungsten carbide. Chronic beryllium disease is a fibrosis with sarcoid-like epitheloid granulomas and is presumably due to a cell-mediated immune response to beryllium. Such a mechanism may be responsible for the pulmonary fibrosis

  13. Investigation of metal-polyelectrolyte complex toxicity.

    Science.gov (United States)

    Karahan, Mesut; Mustafaeva, Zeynep; Koç, Rabia Çakır; Bağırova, Melahat; Allahverdiyev, Adil M

    2014-05-01

    Water-soluble binary and ternary copper complexes of polyelectrolytes were synthesized, and the toxicity of these complexes was tested in mouse fibroblast cell line (L929) in vitro. Both the binary and ternary complexes were prepared at the ratio of 0.4 mole copper(II) ions per monomer of acrylic acid and 0.5 mole copper(II) ions per monomer of methyl vinyl ether maleic anhydride, furthermore at the ratio of 1 and 2 mole bovine serum albumin per mole of polyacrylic acid and poly(methyl vinyl ether-co-maleic anhydride), respectively. Compared to binary copper(II)-polyelectrolyte complexes, these ternary complexes have been determined to be of least toxicity. PMID:22914259

  14. MicroRNAs as regulators in plant metal toxicity response

    Directory of Open Access Journals (Sweden)

    Ana Belen Mendoza-Soto

    2012-05-01

    Full Text Available Metal toxicity is a major stress affecting crop production. This includes metals that are essential for plants (copper, iron, zinc, manganese, and non-essential metals (cadmium, aluminum, cobalt, mercury. A primary common effect of high concentrations of metals such as aluminum, cooper, cadmium or mercury, is root growth inhibition. Metal toxicity triggers the accumulation of reactive oxygen species leading to damage of lipids, proteins and DNA. The plants response to metal toxicity involves several biological processes that require fine and precise regulation at transcriptional and post-transcriptional levels. MicroRNAs (miRNAs are 21 nucleotides non-coding RNAs that regulate gene expression at the post-transcriptional level. A miRNA, incorporated into a RNA induced silencing complex, promotes cleavage of its target mRNA that is recognized by an almost perfect base complementarity. In plants miRNA regulation has been involved in development and also in biotic and abiotic stress responses. We review novel advances in identifying miRNAs related to metal toxicity responses and their potential role according to their targets. Most of the targets for plant metal-responsive miRNAs are transcription factors. Information about metal-responsive miRNAs in different plants points to important regulatory roles of miR319, miR390, miR393 and miR398. The target of miR319 is the TCP transcription factor, implicated in growth control. MiR390 exerts its action through the biogenesis of trans-acting small interference RNAs that, in turn, regulate auxin responsive factors. MiR393 targets the auxin receptors TIR1/AFBs and a bHLH transcription factor. Increasing evidence points to the crucial role of miR398 and its targets Cu/Zn superoxide dismutases in the control of the oxidative stress generated after high metal copper or iron exposure.

  15. Toxicity and mutagenicity of low-metallic automotive brake pad materials.

    Science.gov (United States)

    Malachova, Katerina; Kukutschova, Jana; Rybkova, Zuzana; Sezimova, Hana; Placha, Daniela; Cabanova, Kristina; Filip, Peter

    2016-09-01

    Organic friction materials are standardly used in brakes of small planes, railroad vehicles, trucks and passenger cars. The growing transportation sector requires a better understanding of the negative impact related to the release of potentially hazardous materials into the environment. This includes brakes which can release enormous quantities of wear particulates. This paper addresses in vitro detection of toxic and mutagenic potency of one model and two commercially available low-metallic automotive brake pads used in passenger cars sold in the EU market. The model pad made in the laboratory was also subjected to a standardized brake dynamometer test and the generated non-airborne wear particles were also investigated. Qualitative "organic composition" was determined by GC/MS screening of dichloromethane extracts. Acute toxicity and mutagenicity of four investigated sample types were assessed in vitro by bioluminescence assay using marine bacteria Vibrio fischeri and by two bacterial bioassays i) Ames test on Salmonella typhimurium His(-) and ii) SOS Chromotest using Escherichia coli PQ37 strain. Screening of organic composition revealed a high variety of organic compounds present in the initial brake pads and also in the generated non-airborne wear debris. Several detected compounds are classified by IARC as possibly carcinogenic to humans, e. g. benzene derivatives. Acute toxicity bioassay revealed a response of bacterial cells after exposure to all samples used. Phenolic resin and wear debris were found to be acutely toxic; however in term of mutagenicity the response was negative. All non-friction exposed brake pad samples (a model pad and two commercial pad samples) were mutagenic with metabolic activation in vitro. PMID:27179608

  16. Airborne peptidoglycans as a supporting indicator of bacterial contamination in a metal processing plant

    OpenAIRE

    Marcin Cyprowski; Anna Ławniczek-Wałczyk; Górny, Rafał L.

    2016-01-01

    Objectives: The aim of this study was to assess exposure to airborne endotoxins and peptidoglycans (PGs) as well as possibility of using PGs as a surrogate measure of bacterial exposure in workplaces in a metal processing plant. Material and Methods: Personal dosimetry (N = 11) was used to obtain data on concentrations of viable bacteria, total number of bioaerosol particles, endotoxins and peptidoglycans. To investigate the size distributions of aerosol particles responsible for transport of...

  17. Acute toxicity of 50 metals to Daphnia magna.

    Science.gov (United States)

    Okamoto, Akira; Yamamuro, Masumi; Tatarazako, Norihisa

    2015-07-01

    Metals are essential for human life and physiological functions but may sometimes cause disorders. Therefore, we conducted acute toxicity testing of 50 metals in Daphnia magna: EC50s of seven elements (Be, Cu, Ag, Cd, Os, Au and Hg) were Mo) were > 100,000 µg l(-1) ; and. 7 elements (Ti, Zr, Bi, Nb, Hf, Re and Ta) did not show EC50 at the upper limit of respective aqueous solubility, and EC50s were not obtained. Ga, Ru and Pd adhered to the body of D. magna and physically retarded the movement of D. magna. These metals formed hydroxides after adjusting the pH. Therefore, here, we distinguished this physical effect from the physiological toxic effect. The acute toxicity results of 40 elements obtained in this study were not correlated with electronegativity. Similarly, the acute toxicity results of metals including the rare metals were also not correlated with first ionization energy, atomic weight, atomic number, covalent radius, atomic radius or ionic radius. PMID:25382633

  18. Short-term mechanisms of toxic action of airborne particulates underlie dose-rate dependent health risks and support control of one-hour airborne particle levels

    Energy Technology Data Exchange (ETDEWEB)

    Michaels, R.A.; Kleinman, M.T.

    1999-07-01

    Twenty-four-hour airborne particle mass levels permissible under the NAAQS have been associated with mortality and morbidity in communities, motivating reconsideration of the standard. Reports of shorter-term mechanisms of toxic action exerted by airborne PM and PM constituents are emerging. The mechanisms are diverse, but have in common a short time frame of toxic action, from minutes to hours. In view of documented PM excursions also lasting minutes to hours, this study inquires whether such short-term mechanisms might contribute to explaining daily morbidity and mortality. Toxicology experiments have demonstrated the harmfulness of brief exposure to PM levels in the range of observed excursions. This suggests that toxicological processes initiated by short-term inhalation of PM may exert clinically important effects, and that weak associations of 24-hour-average particle mass with mortality and morbidity may represent artifacts of stronger, shorter-term associations whose full magnitude remains to be quantified. In one study, the area of lung surface developing lesions was elevated in rats breathing the same four-hour dose of aerosols, when the four-hour average rate of aerosol delivery included a short-term (five-minute) burst fifty percent above the average dose rate. Elevations were observed with each of two aerosols tested. The magnitude of the effect was higher with one of the two aerosols, whose dose rate included four excursions rather than just one excursion. Particulate matter inhaled or instilled intratracheally has produced morbidity in animals, including apnea and electrophysiological effects in dogs. Other studies reveal that PM can kill rats via electrophysiological and possibly other mechanisms. PM has also adversely affected asthmatic people in controlled clinical settings during exercise or, in one study, at rest.

  19. Pyrogenic Remobilization And Transport Of Toxic Metals

    OpenAIRE

    Odigie, Kingsley O.

    2014-01-01

    The effects of wildfires and deforestation on the remobilization of persistent inorganic contaminants are not completely understood. In forests, trace metal contaminants (e.g., lead) are sequestered in terrestrial sediment, soil organic matter, and vegetation, where they are relatively immobile. However, the combustion of soil organic matter and vegetation releases these contaminants in more labile forms. The associated deforestation and accelerated weathering increase the mobilization of tra...

  20. Airborne Release of Particles in Overheating Incidents Involving Plutonium Metal and Compounds

    International Nuclear Information System (INIS)

    Ever-increasing utilization of nuclear fuels will result in wide-scale plutonium recovery processing, reconstitution of fuels, transportation, and extensive handling of this material. A variety of circumstances resulting in overheating and fires involving plutonium may occur, releasing airborne particles. This work describes the observations from a study in which the airborne release of plutonium and its compounds was measured during an exposure of the material of interest containing plutonium to temperatures which may result from fires. Aerosol released from small cylinders of metallic plutonium ignited in air at temperatures from 410 to 650°C ranged from 3 x 10-6 to 5 x 10-5 wt%. Particles smaller than 15μm in diameter represented as much as 0.03% of the total released. Large plutonium pieces weighing from 456 to 1770 g were ignited and allowed to oxidize completely in air with a velocity of around 500 cm/sec. Release rates of from 0.0045 to 0.032 wt% per hour were found. The median mass diameter of airborne material was 4 μm. Quenching the oxidation with magnesium oxide sand reduced the release to 2.9 X 10-4 wt% per hour. Many experiments were carried out in which plutonium compounds as powders were heated at temperatures ranging from 700 to 1000°C with several air flows. Release rates ranged from 5 x 10-8 to 0.9 wt% per hour, depending upon the compound and the conditions imposed. The airborne release from boiling solutions of plutonium nitrate were roughly related to energy of boiling, and ranged from 4 x 10-4 to 2 x 10-1 % for the evaporation of 90% of the solution. The fraction airborne when combustibles contaminated with plutonium are burned is under study. The data reported can be used in assessing the consequences of off-standard situations involving plutonium and its compounds in fires. (author)

  1. The airborne sound insulations of metal-framed partitions

    Science.gov (United States)

    Plumb, G. D.

    The sound insulation performances of several lightweight, metal-framed partitions were measured. The aim was to produce a design for a new type of partition which was cheaper than the 'Camden', which is currently used throughout the British Broadcasting Corporation (BBC), while maintaining a comparable sound insulation. As a result of the studies, a partition is recommended for use as an alternative to the Camden. It is provisionally named the 'Warren'. It is much cheaper to build than the Camden and should be more tolerant of poor building practices. It has comparable overall sound insulation properties to that of Camden, but its sound insulation curve is much smoother. Mineral wool in the cavities of the leaves of single or double leaf partitions appreciably increases the sound insulation properties. Adding extra layers of plaster board to single or double Warrens increases the mean sound insulation by an amount that is approximately equal to the increase that would be expected from the increase in mass. Adding mineral wool to these increased mass partitions had only a small effect on their sound insulation.

  2. Heavy metal speciation and toxicity characteristics of tannery sludge

    Science.gov (United States)

    Juel, Md. Ariful Islam; Chowdhury, Zia Uddin Md.; Ahmed, Tanvir

    2016-07-01

    Heavy metals present in tannery sludge can get mobilized in the environment in various forms and can be a cause for concern for the natural ecosystem and human health. The speciation of metals in sludge provides valuable information regarding their toxicity in the environment and determines their suitability for land application or disposal in landfills. Concentrations of seven heavy metals (Cr, Pb, Cd, Ni, Zn, As and Cu) in tannery sludge were determined to evaluate their toxicity levels. Metal contents ranged over the following intervals: As: 1.52-2.07 mg/kg; Pb: 57.5-67 mg/kg; Cr: 15339-26501 mg/kg; Cu: 261.3-579.5 mg/kg; Zn: 210.2-329.1 mg/kg and Ni: 137.5-141.3 mg/kg (dry weight basis). The concentrations of all heavy metals in the sludge samples were lower compared to EPA guidelines except chromium which was found to be several orders of magnitude higher than the guideline value. Toxicity Characteristics Leaching Procedure (TCLP) test indicated that the leaching potential of chromium was higher compared to the other heavy metals and exceeded the EPA land disposal restriction limits. To quantitatively assess the environmental burden of the chromium associated with tannery sludge, the IMPACT 2002+ methodology was adopted under the SimaPro software environment. Considering the USEPA limit for chromium as the baseline scenario, it was found that chromium in the tannery sludge had 6.41 times higher impact than the baseline in the categories of aquatic ecotoxicity, terrestrial ecotoxicity and non-carcinogens. Chromium has the highest contribution to toxicity in the category of aquatic ecotoxicity while copper is the major contributor to the category of terrestrial ecotoxicity in the tannery sludge.

  3. Determination of Toxic Metals in Indian Smokeless Tobacco Products

    Directory of Open Access Journals (Sweden)

    Dhanashri Dhaware

    2009-01-01

    Full Text Available This study targets the lesser-known ingredients of smokeless tobacco products, i.e., the toxic metals, in Indian brands. The metals selected in the study included lead (Pb, cadmium (Cd, arsenic (As, copper (Cu, mercury (Hg, and selenium (Se. The differential pulse anodic stripping voltammetry (DPASV technique was used for estimating the metals Pb, Cd, and Cu; square wave voltammetry for As; and the cold vapor atomic absorption technique for Hg. The resulting levels of the metals were compared to the daily consumption of the smokeless tobacco products. It was observed that almost 30% of gutkha brand samples exceeded the permissible levels of metals Pb and Cu, when compared to the provisional tolerable intake limits determined by the FAO/WHO. The reliability of data was assured by analyzing standard reference materials.

  4. The use of nuclear and related techniques for the studies of possible health impact of airborne particulate matter in a metal industry

    International Nuclear Information System (INIS)

    Various processes in an industry may produce gases and fine airborne particulate matters. Elements and hazardous chemicals in the fine particulate matters may enter the human body through inhalation and direct contact with the skin. Excessive inhalation and contact with the fine airborne particulate matter may lead to intoxication due to excessive intake of the hazardous chemicals and toxic elements. The elements will be accumulated in human organs, such as liver, kidneys and brain, manifest in clinical syndromes such as hypertension, renal failure and neurological symptoms and signs. The absorbed elements are excreted through the urinary tract as urine. They also can be excreted through hair and nails. Elevated blood and urinary aluminum levels have been observed after occupational exposure to various aluminum compounds. This phenomenon indicates the absorption through inhalation, as there are no data indicating significant dermal absorption for aluminum. Absorption of chromium compounds in the workplace occurs mainly through inhalation. The absorption is dependent on the valence and solubility of the particular chromium species. Some elements such as trivalent chromium ions are readily cleared from the blood, but hexavalent chromium ions are retained much longer in the blood. The aluminum compounds vary greatly in their toxic and carcinogenic effects. Although the trivalent chromium is readily excreted, continuous intake may cause the blood chromium level to be higher than normal. These elements may either have an deleterious effect on, or be considered essential for human health. In this study, the levels and health effects of airborne particulate matter in the workplace are assessed by elemental quantification of blood, hair and nail of workers in a metal industry and in airborne particulate samples that are collected at the workplace. The present report represents progress of activities following the first Research Co-ordination Meeting 1997 in Vienna

  5. Recovery of toxic metal ions from washing effluent containing excess aminopolycarboxylate chelant in solution

    OpenAIRE

    Hasegawa, Hiroshi; Rahman, Ismail M. M.; Nakano, Masayoshi; Begum, Zinnat A.; Egawa, Yuji; Maki, Teruya; Furusho, Yoshiaki; Mizutani, Satoshi

    2011-01-01

    Aminopolycarboxylate chelants (APCs) are extremely useful for a variety of industrial applications, including the treatment of toxic metal-contaminated solid waste materials. Because non-toxic matrix elements compete with toxic metals for the binding sites of APCs, an excess of chelant is commonly added to ensure the adequate sequestration of toxic metal contaminants during waste treatment operations. The major environmental impacts of APCs are related to their ability to solubilize toxic hea...

  6. Toxic effects of indoor and outdoor airborne particles relevant to carcinogenesis.

    NARCIS (Netherlands)

    Heussen, G.A.H.

    1993-01-01

    The mutagenicity of indoor and outdoor airborne particulate matter (APM) has been demonstrated by previous in vitro studies (Alink et al., 1983; Van Houdt et al., 1984, 1986, 1987). The aim of the present thesis was to contribute to a better understanding of the mode of action of AIM in the pathogen

  7. Exposure to airborne metals and particulate matter and risk for youth adjudicated for criminal activity

    International Nuclear Information System (INIS)

    Antisocial behavior is a product of multiple interacting sociohereditary variables, yet there is increasing evidence that metal exposure, particularly, manganese and lead, play a role in its epigenesis. Other metals, such as arsenic, cadmium, chromium, and mercury, and exposure to traffic-related air pollution, such as fine particulate matter (≤2.5 μm) have been associated with neurological deficits, yet largely unexplored with respect to their relationship with delinquent behavior. The purpose of this study is to evaluate the ecological relationship between county-wide reported airborne emissions of air metals, particulate matter, and youth adjudicated for criminal activity. Metal exposure data were collected from the Environmental Protection Agency AirData. Population statistics were obtained from the United States Census 2000 and adjudication data was obtained from the Courts of Common Pleases from each Ohio County. Simple correlations were calculated with the percentage of adjudications, all covariates, and estimated metal air emissions. Separate negative binomial regression models for each pollutant were used to provide an estimated risk ratio of pollutant emissions on the risk of adjudication for all Ohio counties adjusting for urban–rural residence, percentage of African Americans, median family income, percentage of family below poverty, percentage of high school graduation in 25 years and older populations, and population density. Metal emissions and PM in 1999 were all correlated with adjudication rate (2003–2005 average). Metal emissions were associated with slightly higher risk of adjudication, with about 3–4% increased risk per natural log unit of metal emission except chromium. The associations achieved statistical significance for manganese and mercury. The particulate matter ≤2.5 and ≤10 μm emissions had a higher risk estimate, with 12% and 19% increase per natural log unit emission, respectively, and also achieved statistical

  8. Exposure to airborne metals and particulate matter and risk for youth adjudicated for criminal activity

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, Erin N., E-mail: Erin.Haynes@uc.edu [College of Medicine, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267 (United States); Chen, Aimin, E-mail: Aimin.Chen@uc.edu [College of Medicine, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267 (United States); Ryan, Patrick, E-mail: Patrick.Ryan@uc.edu [College of Medicine, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267 (United States); Succop, Paul, E-mail: Paul.Succop@uc.edu [College of Medicine, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267 (United States); Wright, John, E-mail: John.Wright@uc.edu [College of Education, Criminal Justice, and Human Services, University of Cincinnati, Cincinnati, OH 45221 (United States); Dietrich, Kim N., E-mail: Kim.Dietrich@uc.edu [College of Medicine, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267 (United States)

    2011-11-15

    Antisocial behavior is a product of multiple interacting sociohereditary variables, yet there is increasing evidence that metal exposure, particularly, manganese and lead, play a role in its epigenesis. Other metals, such as arsenic, cadmium, chromium, and mercury, and exposure to traffic-related air pollution, such as fine particulate matter ({<=}2.5 {mu}m) have been associated with neurological deficits, yet largely unexplored with respect to their relationship with delinquent behavior. The purpose of this study is to evaluate the ecological relationship between county-wide reported airborne emissions of air metals, particulate matter, and youth adjudicated for criminal activity. Metal exposure data were collected from the Environmental Protection Agency AirData. Population statistics were obtained from the United States Census 2000 and adjudication data was obtained from the Courts of Common Pleases from each Ohio County. Simple correlations were calculated with the percentage of adjudications, all covariates, and estimated metal air emissions. Separate negative binomial regression models for each pollutant were used to provide an estimated risk ratio of pollutant emissions on the risk of adjudication for all Ohio counties adjusting for urban-rural residence, percentage of African Americans, median family income, percentage of family below poverty, percentage of high school graduation in 25 years and older populations, and population density. Metal emissions and PM in 1999 were all correlated with adjudication rate (2003-2005 average). Metal emissions were associated with slightly higher risk of adjudication, with about 3-4% increased risk per natural log unit of metal emission except chromium. The associations achieved statistical significance for manganese and mercury. The particulate matter {<=}2.5 and {<=}10 {mu}m emissions had a higher risk estimate, with 12% and 19% increase per natural log unit emission, respectively, and also achieved statistical

  9. Extraction of toxic and valuable metals from foundry sands

    International Nuclear Information System (INIS)

    There were extracted valuable metals from foundry sands such as: gold, platinum, silver, cobalt, germanium, nickel and zinc among others, as well as highly toxic metals such as chromium, lead, vanadium and arsenic. The extraction efficiency was up to 100% in some cases. For this reason there were obtained two patents at the United States, patent number 5,356,601, in October 1994, given for the developed process and patent number 5,376,000, in December 1994, obtained for the equipment employed. Therefore, the preliminary parameters for the installation of a pilot plant have also been developed. (Author)

  10. Fluorescent bioassays for toxic metals in milk and yoghurt

    Directory of Open Access Journals (Sweden)

    Siddiki Mohammad Shohel

    2012-10-01

    Full Text Available Abstract Background From a human health viewpoint, contaminated milk and its products could be a source of long-term exposure to toxic metals. Simple, inexpensive, and on-site assays would enable constant monitoring of their contents. Bioassays that can measure toxic metals in milk or yoghurt might reduce the risk. For this purpose, the green fluorescent protein (GFP-tagged trans factors, ArsR-GFP and CadC-GFP, together with their cis elements were used to develop such bioassays. Results ArsR-GFP or CadC-GFP, which binds either toxic metal or DNA fragment including cis element, was directly mixed with cow’s milk or yoghurt within a neutral pH range. The fluorescence of GFP, which is reflected by the association/dissociation ratio between cis element and trans factor, significantly changed with increasing externally added As (III or Cd (II whereas smaller responses to externally added Pb (II and Zn (II were found. Preparation and dilution of whey fraction at low pH were essential to intrinsic zinc quantification using CadC-GFP. Using the extraction procedure and bioassay, intrinsic Zn (II concentrations ranging from 1.4 to 4.8 mg/l for milk brands and from 1.2 to 2.9 mg/kg for yoghurt brands were determined, which correlated to those determined using inductively coupled plasma atomic emission spectroscopy. Conclusions GFP-tagged bacterial trans factors and cis elements can work in the neutralized whole composition and diluted whey fraction of milk and yoghurt. The feature of regulatory elements is advantageous for establishment of simple and rapid assays of toxic metals in dairy products.

  11. Regional monitoring of metals in the Munich metropolitan area: Comparison of biomonitoring (standardized grass culture) with deposition and airborne particles

    International Nuclear Information System (INIS)

    In the Munich metropolitan area a close association of lead (Pb) and antimony (Sb) impacts with traffic was observed in 1992 and 1993. The intercorrelation of both metals was found by samples of standardised grass cultures and was reflected by deposition sampling, too. With respect to location-specific variations, however, both methods revealed differing gradients of Pb and Sb concentrations with increasing distance from traffic. It appeared that Sb variations according to traffic implications were particularly well indicated by means of biomonitoring, while Pb variations were not indicated adequately. As a result, a special qualification of grass to selectively collect metals on airborne dust according to particle sizes was suggested. Further investigations on the correlations between metal biomonitoring, metal deposition and airborne metals in 1994 - 1996 corroborated method-specific sampling features. They in turn showed that one interference is the individual prevalence of the metals on different particle sizes. (author)

  12. Enhancing toxic metal removal from acidified sludge with nitrite addition.

    Science.gov (United States)

    Du, Fangzhou; Freguia, Stefano; Yuan, Zhiguo; Keller, Jürg; Pikaar, Ilje

    2015-05-19

    The production of sludge (biosolids) during wastewater treatment is a major issue for water utilities. A main issue limiting its beneficial reuse on agricultural lands is the presence of toxic metals. The currently used metal reduction technologies achieve insufficient removal of metals that are bound to the organic fraction of the sludge. In this study, we propose and demonstrate a novel method that involves the addition of nitrite during sludge acidification to enhance metal removal. Using waste activated sludge collected from three full-scale wastewater treatment plants, we found that acidification to pH 2.0 achieved good Zn solubilization of around 70%, but only 3-7% of Cu was being dissolved. Nitrite addition to the acidified sludge at a concentration of 20 mg NO2(-)-N/L (equals to 19.2 mg HNO2-N/L), substantially enhanced Cu removal to 45-64%, while Zn removal was also increased to over 81%. Metal distribution analysis using sequential chemical extraction revealed that the improvement of Cu and Zn removal was mainly due to the release of the organically bound metal fraction. We hypothesize that free nitrous acid (HNO2, FNA) may assist in the (partial) disruption of extracellular polymeric substances (EPS) and the subsequent release and solubilization of fixed metals. PMID:25872418

  13. Metal toxicity- a possible cause of idiopathic pulmonary fibrosis

    International Nuclear Information System (INIS)

    Idiopathic pulmonary fibrosis is a fatal disease of unknown etiology. Attempts are being made in the world to understand the disease mechanism by knowing its causes. Present research is a part to that contribution. Concentrations of some toxic metals were estimated in the blood and lung tissues of the persons diagnosed to be the subject of idiopathic pulmonary fibrosis. IPF subjects were selected for this purpose which was admitted in different hospitals in Lahore. Blood samples were taken directly from the patients whereas lung tissue samples were collected from the relevant biopsy labs. Three control blood samples were also collected from healthy persons. The samples were digested with Conc. HNO/sub 3/ to make their solutions for the estimation of metals. The metals selected were Cu, Pb, Cd, Cr, Be, Zn, Al, As and Co. Atomic Absorption Spectrophotometer (AAS) was used to estimate the metal concentrations in the sample solutions. The mean values of the concentrations (ppm) of these metals in the blood samples were Cu (0.65), Pb(0.69), Cd(1.17), Cr(0.21), Be(0.67), Zn(6.31), Al(1.33), As(0.46) and Co(0.46). The mean values of the concentrations (ppm) of these metals in the lung tissue samples were Cu (1.57), Pb(1.01), Cd(1.70), Cr(0.46), Be(2.02), Zn(10.20), Al(1.68), As(0.83) and Co(0.65). The concentrations of these metals were also estimated in the blood samples of control healthy persons and compared with the subjects. The difference of concentrations (ppm) in the blood samples of IPF subjects and Control Maximum (Mean Subjects - Control Max.) were Cu (0.50), Pb(0.62), Cd(1.17), Cr(0.21), Be(0.56), Zn(5.06), Al(1.31), As(0.46) and Co(0.46). Comparison of the mean values of concentrations of metals in blood samples of IPF subjects with the maximum concentration of metals in the blood samples of control healthy persons shows that metals levels are higher in the subjects than the control ones. i.e. Cu(76.92%), Pb(89.6%), Cd(100%), Cr(100%), Be(83.58%), Zn(80

  14. Acute toxicity of heavy metals towards freshwater ciliated protists

    International Nuclear Information System (INIS)

    The acute toxicity of five heavy metals to four species of freshwater ciliates (Colpidium colpoda, Dexiotricha granulosa, Euplotes aediculatus, and Halteria grandinella) was examined in laboratory tests. After exposing the ciliates to soluble compound of cadmium, copper, chromium, lead, and nickel at several selected concentrations, the mortality rate was registered and the LC5 values (with 95% confidence intervals) were calculated. Large differences appeared in sensitivities of the four species to the metals. H. grandinella showed the highest sensitivity for cadmium (0.07 mg l-1, LC5) and lead (0.12 mg l-1, LC5), whilst E. aediculatus showed the highest sensitivity for nickel (0.03 mg l-1, LC5). The comparison with data obtained with other species indicate that Halteria grandinella and Euplotes aediculatus are excellent and convenient bioindicator for evaluating the toxicity of waters and wastewaters polluted by heavy metals. The short time (24 h) and simplicity of the test procedure enable this test to be used in laboratory studies. - Ciliated protozoa are suitable bioindicators of heavy metal pollution in freshwater environments

  15. Identifying airborne metal particles sources near an optoelectronic and semiconductor industrial park

    Science.gov (United States)

    Chen, Ho-Wen; Chen, Wei-Yea; Chang, Cheng-Nan; Chuang, Yen-Hsun; Lin, Yu-Hao

    2016-06-01

    The recently developed Central Taiwan Science Park (CTSP) in central Taiwan is home to an optoelectronic and semiconductor industrial cluster. Therefore, exploring the elemental compositions and size distributions of airborne particles emitted from the CTSP would help to prevent pollution. This study analyzed size-fractionated metal-rich particle samples collected in upwind and downwind areas of CTSP during Jan. and Oct. 2013 by using micro-orifice uniform deposited impactor (MOUDI). Correlation analysis, hierarchical cluster analysis and particle mass-size distribution analysis are performed to identify the source of metal-rich particle near the CTSP. Analyses of elemental compositions and particle size distributions emitted from the CTSP revealed that the CTSP emits some metals (V, As, In Ga, Cd and Cu) in the ultrafine particles (pollution index for optoelectronic and semiconductor emission in the CTSP. Meanwhile, the ratios of As/Ga concentration at the particle size of 0.32 μm demonstrates that humans near the CTSP would be potentially exposed to GaAs ultrafine particles. That is, metals such as Ga and As and other metals that are not regulated in Taiwan are potentially harmful to human health.

  16. Semen quality and heavy metal and pesticides toxicity

    Directory of Open Access Journals (Sweden)

    Lidia Mínguez-Alarcón

    2014-06-01

    Full Text Available Male reproductive function has deteriorated significantly in the past 50 years and this change could be related to an exposure to occupational and environmental pollutants and toxicants. The purpose of this paper is to summarize the negative impact of human exposure to heavy metals and pesticides on the male reproductive function. Most pesticides and heavy metals are considered reproductive toxicants and may adversely harm the male reproductive system due to their disrupting effect on the hypothalamus- pituitary gland-gonads axis or by directly affecting spermatogenesis, resulting in impaired semen quality. The negative effects of these compounds have been linked to the main sperm parameters (concentration, normal morphology and motility, semen volume and total sperm count and DNA sperm damage, as well as to changes in serum reproductive hormone levels. Some of these substances have already been banned, whereas others are still on the market. Stricter laws are needed to completely prevent exposure to these toxicants given their proven deleterious effect on male reproductive health.

  17. Assessment of toxic metals in waste personal computers

    International Nuclear Information System (INIS)

    Highlights: • Waste personal computers were collected and dismantled in their main parts. • Motherboards, monitors and plastic housing were examined in their metal content. • Concentrations measured were compared to the RoHS Directive, 2002/95/EC. • Pb in motherboards and funnel glass of devices released <2006 was above the limit. • Waste personal computers need to be recycled and environmentally sound managed. - Abstract: Considering the enormous production of waste personal computers nowadays, it is obvious that the study of their composition is necessary in order to regulate their management and prevent any environmental contamination caused by their inappropriate disposal. This study aimed at determining the toxic metals content of motherboards (printed circuit boards), monitor glass and monitor plastic housing of two Cathode Ray Tube (CRT) monitors, three Liquid Crystal Display (LCD) monitors, one LCD touch screen monitor and six motherboards, all of which were discarded. In addition, concentrations of chromium (Cr), cadmium (Cd), lead (Pb) and mercury (Hg) were compared with the respective limits set by the RoHS 2002/95/EC Directive, that was recently renewed by the 2012/19/EU recast, in order to verify manufacturers’ compliance with the regulation. The research included disassembly, pulverization, digestion and chemical analyses of all the aforementioned devices. The toxic metals content of all samples was determined using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The results demonstrated that concentrations of Pb in motherboards and funnel glass of devices with release dates before 2006, that is when the RoHS Directive came into force, exceeded the permissible limit. In general, except from Pb, higher metal concentrations were detected in motherboards in comparison with plastic housing and glass samples. Finally, the results of this work were encouraging, since concentrations of metals referred in the RoHS Directive were found in

  18. Assessment of toxic metals in waste personal computers

    Energy Technology Data Exchange (ETDEWEB)

    Kolias, Konstantinos; Hahladakis, John N., E-mail: john_chach@yahoo.gr; Gidarakos, Evangelos, E-mail: gidarako@mred.tuc.gr

    2014-08-15

    Highlights: • Waste personal computers were collected and dismantled in their main parts. • Motherboards, monitors and plastic housing were examined in their metal content. • Concentrations measured were compared to the RoHS Directive, 2002/95/EC. • Pb in motherboards and funnel glass of devices released <2006 was above the limit. • Waste personal computers need to be recycled and environmentally sound managed. - Abstract: Considering the enormous production of waste personal computers nowadays, it is obvious that the study of their composition is necessary in order to regulate their management and prevent any environmental contamination caused by their inappropriate disposal. This study aimed at determining the toxic metals content of motherboards (printed circuit boards), monitor glass and monitor plastic housing of two Cathode Ray Tube (CRT) monitors, three Liquid Crystal Display (LCD) monitors, one LCD touch screen monitor and six motherboards, all of which were discarded. In addition, concentrations of chromium (Cr), cadmium (Cd), lead (Pb) and mercury (Hg) were compared with the respective limits set by the RoHS 2002/95/EC Directive, that was recently renewed by the 2012/19/EU recast, in order to verify manufacturers’ compliance with the regulation. The research included disassembly, pulverization, digestion and chemical analyses of all the aforementioned devices. The toxic metals content of all samples was determined using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The results demonstrated that concentrations of Pb in motherboards and funnel glass of devices with release dates before 2006, that is when the RoHS Directive came into force, exceeded the permissible limit. In general, except from Pb, higher metal concentrations were detected in motherboards in comparison with plastic housing and glass samples. Finally, the results of this work were encouraging, since concentrations of metals referred in the RoHS Directive were found in

  19. Using metal-ligand binding characteristics to predict metal toxicity: quantitative ion character-activity relationships (QICARs).

    OpenAIRE

    Newman, M C; McCloskey, J T; Tatara, C P

    1998-01-01

    Ecological risk assessment can be enhanced with predictive models for metal toxicity. Modelings of published data were done under the simplifying assumption that intermetal trends in toxicity reflect relative metal-ligand complex stabilities. This idea has been invoked successfully since 1904 but has yet to be applied widely in quantitative ecotoxicology. Intermetal trends in toxicity were successfully modeled with ion characteristics reflecting metal binding to ligands for a wide range of ef...

  20. Newer systems for bacterial resistances to toxic heavy metals.

    OpenAIRE

    Silver, S; Ji, G.

    1994-01-01

    Bacterial plasmids contain specific genes for resistances to toxic heavy metal ions including Ag+, AsO2-, AsO4(3-), Cd2+, Co2+, CrO4(2-), Cu2+, Hg2+, Ni2+, Pb2+, Sb3+, and Zn2+. Recent progress with plasmid copper-resistance systems in Escherichia coli and Pseudomonas syringae show a system of four gene products, an inner membrane protein (PcoD), an outer membrane protein (PcoB), and two periplasmic Cu(2+)-binding proteins (PcoA and PcoC). Synthesis of this system is governed by two regulator...

  1. Phytoextraction of toxic metals by sunflower and corn plants

    Czech Academy of Sciences Publication Activity Database

    Soudek, Petr; Petrová, Šárka; Benešová, Dagmar; Vaněk, Tomáš

    2010-01-01

    Roč. 8, 3-4 (2010), s. 383-390. ISSN 1459-0255 R&D Projects: GA MŠk 2B08058; GA MŠk 1M06030; GA MŠk OC09082 Institutional research plan: CEZ:AV0Z50380511 Keywords : Toxic metals * lead * zinc Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides Impact factor: 0.425, year: 2010 www.isfae.org/scientficjournal/2010/issue3/abstracts/abstract68.php

  2. An application of the biotic ligand model to predict the toxic effects of metal mixtures.

    Science.gov (United States)

    Kamo, Masashi; Nagai, Takashi

    2008-07-01

    The rapidly developing biotic ligand model (BLM) allows us to predict the toxicity of heavy metals in water of various chemistries; however, the current BLM predicts the toxicity of a single metal and not the toxic effects of metal mixtures. The toxic mechanisms of heavy metals are not yet completely understood, but hypocalcemia is suggested to be the most likely toxic mechanism for some metals. The BLM, which predicts the toxicity of metals by the amount of metals binding to ligand, is modified to predict the toxicity by the proportion of nonmetal binding ligand that is available for calcium uptake under the assumption that the organisms die because of hypocalcemia when so few ligands are available for calcium uptake. Because the proportion can be computed when multiple metals are present, the toxic effects of metal mixtures can be predicted. Zinc, copper, and cadmium toxicity to rainbow trout (Oncorhynchus mykiss) are considered. All data are collected from the literature, and a meta-analysis using the modified version of the BLM is conducted. The present study found that the proportion of nonmetal binding ligand is a constant value for any test condition. The proportion is not influenced by water chemistry or by metal species. Using the nature of constant proportion, toxicities of metals are well estimated. In addition, the toxic effects of metal mixtures are the simple sum of the toxicities of each metal (additive effect) corresponding to the bioavailable form of the metals. In terms of total concentration of metals in water, however, nonadditive effects, such as antagonism and synergism, are possible. PMID:18260697

  3. Analysis of toxic metals in branded Pakistani herbal products

    International Nuclear Information System (INIS)

    The present study was designed to estimate the concentration of heavy toxic metals in Pakistani herbal products frequently used for the treatment of various ailments. For this purpose, twenty five herbal products of well reputed herbal manufacturers were selected. The results of our investigation revealed that the concentrations of lead, cadmium, nickel and chromium were far beyond the permissible limits proposed by the International Regulatory Authorities for herbal drugs. Therefore, this study conveys a strong message to the ministry of health to establish proper rules and regulations for the validation of herbal products on scientific grounds in order to protect the general public from the harmful effects of these heavy metals in herbal products. (author)

  4. Competitive transport of toxic metal ions by polymer inclusion membranes

    International Nuclear Information System (INIS)

    A short overview of application of polymer inclusion membranes (PIMs) for separation and removal of metal ions is given. Investigation of the selective removal of toxic metal ions, i.e. Cr(VI), Cd(II), Zn(II) from acidic chloride aqueous solutions, as well as trace radionuclides, i.e., 137Cs, 90Sr and 60Co from wastewaters using transport across polymer inclusion membranes was studied. The carriers, i.e., tri-n-octylamine for anionic metal species, as well as dibenzo-21-crown-7, tertbutyl-dibenzo-21-crown-7, and dinonylnaphtalenesulfonic acid for metal cations were incorporated into polymer inclusion membranes composed of cellulose triacetate as a support and o-nitrophenyl pentyl ether as a plasticizer. Selective transport of chromium(VI) over zinc(II) and cadmium(II) chloride complexes through PIMs was observed. Competitive transport of trace radionuclide ions, i.e., 137Cs, 90Sr, and 60Co from NaNo3 aqueous solutions across polymer inclusion membranes containing a mixture of dinonylnaphtalenesulfonic acid, and dibenzo-21-crown-7 as the carrier provide the selectivity order Cs(I)>Sr(II)>Co(II). (author)

  5. Delayed luminescence of microalgae as an indicator of metal toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Scordino, A; Musumeci, F; Gulino, M; Lanzano, L; Grasso, R; Triglia, A [Dipartimento di Metodologie Fisiche e Chimiche per l' Ingegneria, Universita di Catania, v.le Andrea Doria, 6, 95125 Catania (Italy); Tudisco, S; Sui, L [Laboratori Nazionali del Sud - Istituto Nazionale di Fisica Nucleare, Via S Sofia 44, 95123 Catania (Italy)], E-mail: ascordin@dmfci.unict.it, E-mail: fmusumec@dmfci.unict.it, E-mail: mgulino@dmfci.unict.it, E-mail: lanzano-l@lns.infn.it, E-mail: tudisco@lns.infn.it, E-mail: lisui@ciae.ac.cn, E-mail: rgrasso@dmfci.unict.it, E-mail: atriglia@dmfci.unict.it

    2008-08-07

    The delayed luminescence (DL) (i.e. the photo-induced photon emission long after the illumination is switched off) of unicellular green algae samples has been measured when different concentrations of heavy metals are added to the standard culture medium, with the aim of assessing the DL as a promising approach for assaying the toxicity of contaminants such as metals. In particular, samples of freshwater green micro-algae Selenastrum capricornutum have been used. Concentrations of cadmium, chromium, lead and copper, ranging from 10{sup -5} to 10{sup -2} M, have been tested. The analysis of the decay trends, in the time interval from tens of microseconds to seconds, of the DL spectral components demonstrates that the DL parameters are sensitive to the presence of such pollutants. More precisely, the performed analysis allowed us to determine phenomenological relationships between the DL parameters and the metal concentration that could be used in view of the possibility of realizing a biosensor for water pollution detection. Attempts to distinguish between different contaminants are also described. Results of this preliminary study show that the DL measure based technique is suitable as a general bioassay of metal contamination and it could also be used to test the efficiency in bioavailability studies.

  6. Delayed luminescence of microalgae as an indicator of metal toxicity

    International Nuclear Information System (INIS)

    The delayed luminescence (DL) (i.e. the photo-induced photon emission long after the illumination is switched off) of unicellular green algae samples has been measured when different concentrations of heavy metals are added to the standard culture medium, with the aim of assessing the DL as a promising approach for assaying the toxicity of contaminants such as metals. In particular, samples of freshwater green micro-algae Selenastrum capricornutum have been used. Concentrations of cadmium, chromium, lead and copper, ranging from 10-5 to 10-2 M, have been tested. The analysis of the decay trends, in the time interval from tens of microseconds to seconds, of the DL spectral components demonstrates that the DL parameters are sensitive to the presence of such pollutants. More precisely, the performed analysis allowed us to determine phenomenological relationships between the DL parameters and the metal concentration that could be used in view of the possibility of realizing a biosensor for water pollution detection. Attempts to distinguish between different contaminants are also described. Results of this preliminary study show that the DL measure based technique is suitable as a general bioassay of metal contamination and it could also be used to test the efficiency in bioavailability studies

  7. Daphnia magna ecotoxicogenomics provides mechanistic insights into metal toxicity.

    Science.gov (United States)

    Poynton, Helen C; Varshavsky, Julia R; Chang, Bonnie; Cavigiolio, Giorgio; Chan, Sarah; Holman, Patricia S; Loguinov, Alexandre V; Bauer, Darren J; Komachi, Kelly; Theil, Elizabeth C; Perkins, Edward J; Hughes, Owen; Vulpe, Chris D

    2007-02-01

    Toxicogenomics has provided innovative approaches to chemical screening, risk assessment, and predictive toxicology. If applied to ecotoxicology, genomics tools could greatly enhance the ability to understand the modes of toxicity in environmentally relevant organisms. Daphnia magna, a small aquatic crustacean, is considered a "keystone" species in ecological food webs and is an indicator species for toxicant exposure. Our objective was to demonstrate the potential utility of gene expression profiling in ecotoxicology by identifying novel biomarkers and uncovering potential modes of action in D. magna. Using a custom D. magna cDNA microarray, we identified distinct expression profiles in response to sublethal copper, cadmium, and zinc exposures and discovered specific biomarkers of exposure including two probable metallothioneins, and a ferritin mRNA with a functional IRE. The gene expression patterns support known mechanisms of metal toxicity and reveal novel modes of action including zinc inhibition of chitinase activity. By integrating gene expression profiling into an environmentally important organism, this study provides experimental support for the utility of ecotoxicogenomics. PMID:17328222

  8. Characterization of Airborne Particles in an Electronic Waste Recycling Facility and Their Toxicity Assessment

    Science.gov (United States)

    Improper disposal of electronic waste (e-waste) can lead to release of toxic chemicals into the environment and also may pose health risks. Thus, recycling e-waste, instead of landfilling, is considered to be an effective way to reduce pollutant release and exposure. However, lit...

  9. Toxic metals in WEEE: Characterization and substance flow analysis in waste treatment processes

    International Nuclear Information System (INIS)

    Waste electrical and electronic equipment (WEEE) has received extensive attention as a secondary source of metals. Because WEEE also contains toxic substances such as heavy metals, appropriate management of these substances is important in the recycling and treatment of WEEE. As a basis for discussion toward better management of WEEE, this study characterizes various types of WEEE in terms of toxic metal contents. The fate of various metals contained in WEEE, including toxic metals, was also investigated in actual waste treatment processes. Cathode-ray tube televisions showed the highest concentration and the largest total amount of toxic metals such as Ba, Pb, and Sb, so appropriate recycling and disposal of these televisions would greatly contribute to better management of toxic metals in WEEE. A future challenge is the management of toxic metals in mid-sized items such as audio/visual and ICT equipment because even though the concentrations were not high in these items, the total amount of toxic metals contained in them is not negligible. In the case of Japan, such mid-sized WEEE items as well as small electronic items are subject to municipal solid waste treatment. A case study showed that a landfill was the main destination of toxic metals contained in those items in the current treatment systems. The case study also showed that changes in the flows of toxic metals will occur when treatment processes are modified to emphasize resource recovery. Because the flow changes might lead to an increase in the amount of toxic metals released to the environment, the flows of toxic metals and the materials targeted for resource recovery should be considered simultaneously. - Highlights: ► Appropriate management of toxic metals contained in WEEE is important during recycling and treatment of WEEE. ► CRT TVs contain large amount of toxic metals with high concentration and thus appropriate management is highly important. ► Mid-sized equipment is a future target for

  10. Toxicity assessment due to sub-chronic exposure to individual and mixtures of four toxic heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Cobbina, Samuel J.; Chen, Yao [School of the Environment, Jiangsu University, Xuefu Rd. 301, Zhenjiang 212013, Jiangsu (China); Zhou, Zhaoxiang; Wu, Xueshan; Zhao, Ting [School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Rd. 301, Zhenjiang 212013 (China); Zhang, Zhen [School of the Environment, Jiangsu University, Xuefu Rd. 301, Zhenjiang 212013, Jiangsu (China); Feng, Weiwei; Wang, Wei [School of Food and Biological Engineering, Jiangsu University, Xuefu Rd. 301, Zhenjiang 212013, Jiangsu (China); Li, Qian [School of Pharmacy, Jiangsu University, Xuefu Rd. 301, Zhenjiang 212013, Jiangsu (China); Wu, Xiangyang, E-mail: wuxy@ujs.edu.cn [School of the Environment, Jiangsu University, Xuefu Rd. 301, Zhenjiang 212013, Jiangsu (China); Yang, Liuqing, E-mail: yangliuqing@ujs.edu.cn [School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Rd. 301, Zhenjiang 212013 (China)

    2015-08-30

    Highlights: • Low dose single and mixtures of toxic metals had adverse effect on mice. • Metal mixtures exhibited higher toxicities compared to individual metals. • Mixtures of low dose Pb + Hg + Cd induced neuronal degeneration in brain of mice. • Exposure to Pb + Hg + As + Cd showed renal tubular necrosis in kidney. - Abstract: Humans are exposed to a cocktail of heavy metal toxicants in the environment. Though heavy metals are deleterious, there is a paucity of information on toxicity of low dose mixtures. In this study, lead (Pb) (0.01 mg/L), mercury (Hg) (0.001 mg/L), cadmium (Cd) (0.005 mg/L) and arsenic (As) (0.01 mg/L) were administered individually and as mixtures to 10 groups of 40 three-week old mice (20 males and 20 females), for 120 days. The study established that low dose exposures induced toxicity to the brain, liver, and kidney of mice. Metal mixtures showed higher toxicities compared to individual metals, as exposure to low dose Pb + Hg + Cd reduced brain weight and induced structural lesions, such as neuronal degeneration in 30-days. Pb + Hg + Cd and Pb + Hg + As + Cd exposure induced hepatocellular injury to mice evidenced by decreased antioxidant activities with marginal increases in MDA. These were accentuated by increases in ALT, AST and ALP. Interactions in metal mixtures were basically synergistic in nature and exposure to Pb + Hg + As + Cd induced renal tubular necrosis in kidneys of mice. This study underlines the importance of elucidating the toxicity of low dose metal mixtures so as to protect public health.

  11. Toxic metals in WEEE: characterization and substance flow analysis in waste treatment processes.

    Science.gov (United States)

    Oguchi, Masahiro; Sakanakura, Hirofumi; Terazono, Atsushi

    2013-10-01

    Waste electrical and electronic equipment (WEEE) has received extensive attention as a secondary source of metals. Because WEEE also contains toxic substances such as heavy metals, appropriate management of these substances is important in the recycling and treatment of WEEE. As a basis for discussion toward better management of WEEE, this study characterizes various types of WEEE in terms of toxic metal contents. The fate of various metals contained in WEEE, including toxic metals, was also investigated in actual waste treatment processes. Cathode-ray tube televisions showed the highest concentration and the largest total amount of toxic metals such as Ba, Pb, and Sb, so appropriate recycling and disposal of these televisions would greatly contribute to better management of toxic metals in WEEE. A future challenge is the management of toxic metals in mid-sized items such as audio/visual and ICT equipment because even though the concentrations were not high in these items, the total amount of toxic metals contained in them is not negligible. In the case of Japan, such mid-sized WEEE items as well as small electronic items are subject to municipal solid waste treatment. A case study showed that a landfill was the main destination of toxic metals contained in those items in the current treatment systems. The case study also showed that changes in the flows of toxic metals will occur when treatment processes are modified to emphasize resource recovery. Because the flow changes might lead to an increase in the amount of toxic metals released to the environment, the flows of toxic metals and the materials targeted for resource recovery should be considered simultaneously. PMID:22921510

  12. Metal and proton toxicity to lake zooplankton: A chemical speciation based modelling approach

    International Nuclear Information System (INIS)

    The WHAM-FTOX model quantifies the combined toxic effects of protons and metal cations towards aquatic organisms through the toxicity function (FTOX), a linear combination of the products of organism-bound cation and a toxic potency coefficient for each cation. We describe the application of the model to predict an observable ecological field variable, species richness of pelagic lake crustacean zooplankton, studied with respect to either acidification or the impacts of metals from smelters. The fitted results give toxic potencies increasing in the order H+ TOX to relate combined toxic effects of protons and metal cations towards lake crustacean zooplankton. • The fitted results give toxic potencies increasing in the order H+ TOX model has been applied to field data for pelagic lake crustacean zooplankton. The fitted results give metal toxic potencies increasing in the order H+ < Al < Cu < Zn < Ni

  13. Joint toxic action of binary metal mixtures of copper, manganese and nickel to Paronychiurus kimi (Collembola).

    Science.gov (United States)

    Son, Jino; Lee, Yun-Sik; Kim, Yongeun; Shin, Key-Il; Hyun, Seunghun; Cho, Kijong

    2016-10-01

    The joint toxic effects of binary metal mixtures of copper (Cu), manganese (Mn) and nickel (Ni) on reproduction of Paronhchiurus kimi (Lee) was evaluated using a toxic unit (TU) approach by judging additivity across a range of effect levels (10-90%). For all metal mixtures, the joint toxic effects of metal mixtures on reproduction of P. kimi decreased in a TU-dependent manner. The joint toxic effects of metal mixtures also changed from less than additive to more than additive at an effect level lower than or equal to 50%, while a more than additive toxic effects were apparent at higher effect levels. These results indicate that the joint toxicity of metal mixtures is substantially different from that of individual metals based on additivity. Moreover, the close relationship of toxicity to effect level suggests that it is necessary to encompass a whole range of effect levels rather than a specific effect level when judging mixture toxicity. In conclusion, the less than additive toxicity at low effect levels suggests that the additivity assumption is sufficiently conservative to warrant predicting joint toxicity of metal mixtures, which may give an additional margin of safety when setting soil quality standards for ecological risk assessment. PMID:27318557

  14. Microbial removal of toxic metals from a heavily polluted soil

    Science.gov (United States)

    Nicolova, Marina; Spasova, Irena; Georgiev, Plamen; Groudev, Stoyan

    2015-04-01

    Samples of a leached cinnamonic forest soil heavily polluted with uranium and some toxic heavy metals (mainly copper, zinc and cadmium) were subjected to cleaning by means of bioleaching with acidophilic chemolithotrophic bacteria. The treatment was carried out in a green house in which several plots containing 150 kg of soil each were constructed. The effect of some essential environmental factors such as pH, humidity, temperature and contents of nutrients on the cleaning process was studied. It was found that under optimal conditions the content of pollutants were decreased below the relevant permissible levels within a period of 170 days. The soil cleaned in this way was characterized by a much higher production of biomass of different plants (alfalfa, clover, red fescue, vetch) than the untreated polluted soil.

  15. Biomphalaria alexandrina as a bioindicator of metal toxicity.

    Science.gov (United States)

    Habib, Mohamed R; Mohamed, Azza H; Osman, Gamalat Y; Mossalem, Hanan S; Sharaf El-Din, Ahmed T; Croll, Roger P

    2016-08-01

    Heavy metals are common environmental pollutants to the aquatic ecosystems. Several aquatic species have been used as bioindicators and biomonitoring subjects for heavy metals pollution. In the present study, the effects of cadmium (Cd) and manganese (Mn) on the survival, attachment, locomotion, and feeding behaviours of the gastropod snail Biomphalaria alexandrina were determined. The short-term (96 h) LC50 for Cd and Mn were found to be 0.219 and 154.2 mg/l, respectively. Long-term exposures (16-20 days) to ascending concentrations of Cd (0.01-1 mg/l) and Mn (50-500 mg/l) also caused gradual decreases in the survival rate of B. alexandrina in a dose-dependent manner. Attachment, locomotion and feeding behaviours of snails exposed to lethal and sublethal concentrations of Cd and Mn at acute (96 h) and chronic exposure (24 days) intervals, respectively, were also recorded. Compared to controls, a significant decrease (p ≤ 0.05) was recorded in the different behaviours of exposed snails. These changes in behaviour would potentially impact the snail's ability to survive in the wild. Although Cd caused a more severe decline in snail survivorship than Mn, the behavioural effects of Mn were much more severe than Cd when the metals were roughly matched for lethality. In sum, the present study demonstrates B. alexandrina to be a sensitive bioindicator and model organism to assess heavy metals risk factors for severe toxicity in freshwater ecosystems. PMID:27209558

  16. Airborne peptidoglycans as a supporting indicator of bacterial contamination in a metal processing plant

    Directory of Open Access Journals (Sweden)

    Marcin Cyprowski

    2016-03-01

    Full Text Available Objectives: The aim of this study was to assess exposure to airborne endotoxins and peptidoglycans (PGs as well as possibility of using PGs as a surrogate measure of bacterial exposure in workplaces in a metal processing plant. Material and Methods: Personal dosimetry (N = 11 was used to obtain data on concentrations of viable bacteria, total number of bioaerosol particles, endotoxins and peptidoglycans. To investigate the size distributions of aerosol particles responsible for transport of endotoxins and PGs, air samples (N = 5 were additionally collected using the 8-stage cascade impactor. Endotoxins and PGs were assayed with the Limulus amebocyte lysate (LAL test and a kinetic version of the silkworm larvae plasma (SLP test, respectively. Results: Median concentrations of airborne PGs (14.6 ng/m3, endotoxins (0.2 ng/m3, viable bacteria (1.16×103 CFU/m3 and the total number of bioaerosol particles (1.81×106 cells/m3 were determined. Qualitative analysis revealed presence of 19 bacterial species belonging to 14 genera. The calculations showed strong, significant correlations (p < 0.05 between endotoxins, viable bacteria (r = 0.75 and the total number of bioaerosol particle concentrations (r = 0.76 as well as between PGs and the total number of bioaerosol particle concentrations (r = 0.72. Size distribution analysis showed that the highest concentrations of bacterial aerosols occurred in the range of 2.1–3.3 μm. In the case of endotoxins, an increase of concentrations in 2 ranges of aerodynamic diameters: 1.1–3.3 μm and 5.8–9 μm was shown. For PGs there was a visible gradual increase of their concentrations in the range 2.1–9 μm. Conclusions: Peptidoglycans can be treated as a supporting indicator of bacterial contamination in metal processing plants, particularly when an assessment of an immunotoxic potential of microbiological hazards needs to be performed. However, to be extrapolated to other occupational and non

  17. TOF-SIMS measurements for toxic air pollutants adsorbed on the surface of airborne particles

    Science.gov (United States)

    Tomiyasu, Bunbunoshin; Hoshi, Takahiro; Owari, Masanori; Nihei, Yoshimasa

    2003-01-01

    Three kinds of particulate matter were collected: diesel and gasoline exhaust particles emitted directly from exhaust nozzle, and suspended particulate matter (SPM) near the traffic route. Soxhlet extraction was performed on each sample. By gas-chromatograph-mass spectrometer (GC-MS) analysis of these extracts, di-ethyl phthalate and di- n-butyl phthalate were detected from the extract of SPM and diesel exhaust particles (DEPs). Because these phthalates were sometimes suspected as contamination, time-of-flight secondary ion mass spectrometry (TOF-SIMS) measurements were also performed on the samples collected at the same environment. By comparing obtained spectra, it is clear that these environmental endocrine disrupters (EEDs) were adsorbed on DEP surface. Thus, we concluded that the combination of conventional method and TOF-SIMS measurement is one of the most powerful techniques for analyzing the toxic air pollutants adsorbed on SPM surface.

  18. Toxicity of metallic oxides nanoparticle suspensions to a freshwater sludge worm Tubifex tubifex Müller.

    Science.gov (United States)

    Verma, Surabhi; Das, Sangita; Khangarot, B S

    2011-02-01

    Toxic effects of selected metallic oxides nanoparticles were studied using the short-term static bioassays. Nanoparticles were more toxic than comparable bulk metallic oxides. Freshwater sludge worm Tubifex tubifex can be used as suitable test model for nanoecotoxicological studies in future studies. PMID:21485877

  19. Metal and pharmaceutical mixtures: Is ion loss the mechanism underlying acute toxicity and widespread additive toxicity in zebrafish?

    International Nuclear Information System (INIS)

    Highlights: •Zebrafish larvae were used to test the acute toxicity of contaminant mixtures. •Interactions were observed between metals, ammonia and pharmaceuticals. •Larval Na+ loss was observed with exposure to all acutely toxic contaminants tested. •Water quality criteria should recognize the toxic interactions between contaminants. -- Abstract: The acute toxicities and mechanisms of action of a variety of environmental contaminants were examined using zebrafish larvae (Danio rerio; 4–8 days post fertilization). Toxic interactions were observed between metals. For example, the addition of a sublethal level of nickel (15% of the LC50, one third of the LC01) to all copper treatments decreased the copper 96 h LC50 by 58%, while sublethal copper exposure (6% of the copper LC50, 13% of the LC01) decreased the cadmium 96 h LC50 by 47%. Two predictive models were assessed, the concentration addition (CA) model, which assumes similar mechanisms of action, and the independent action (IA) model, which assumes different mechanisms of action. Quantitative comparisons indicated the CA model performed better than the IA model; the latter tended to underestimate combined toxicity to a greater extent. The effects of mixtures with nickel or ammonia were typically additive, while mixtures with copper or cadmium were typically greater than additive. Larvae exposed to cadmium, copper or nickel experienced whole body ion loss. Decreases were greatest for Na+ followed by K+ (as high as 19% and 9%, respectively, in 24 h). Additive toxicity between copper and other pharmaceutical compounds such as fluoxetine (Prozac™), β-naphthoflavone, estrogen and 17α-ethinylestradiol were also observed. Similar to metals, acutely toxic concentrations of fluoxetine, β-naphthoflavone and ammonia all decreased whole body Na+ and K+. Overall, whole body Na+ loss showed the greatest correlation with mortality across a variety of toxicants. We theorize that a disruption of ion homeostasis

  20. Metal stoichiometry in predicting Cd and Cu toxicity to a freshwater green alga Chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    In this study, we quantified the accumulation and toxicity of cadmium and copper in a freshwater green alga, Chlamydomonas reinhardtii, under different phosphate conditions. The accumulated Cd and Cu concentrations increased significantly with increasing ambient P concentrations and free metal ion concentrations. The metal:P ratio remained independent of the ambient P concentration. For the three pulse-amplitude-modulated parameters, the median inhibition concentrations were 1.5-1.6x and 2.0x higher, but the medium inhibition cellular quota was 2.2x and 1.2x lower for cells maintained at 0.1 μM P than for cells maintained at 10 μM P for Cd and Cu, respectively. Furthermore, the difference in metal toxicity decreased (for Cd) or disappeared (for Cu) when the toxicity was expressed by the metal:P ratio in the cells, indicating that the stoichiometry of metals and P can be better used to predict the toxicity of metals. It is necessary to consider the stoichiometry of metals in predicting metal toxicity in phytoplankton. - The stoichiometry of metals and P can be used to predict metal toxicity to freshwater phytoplankton under different P conditions

  1. Gender differences in the disposition and toxicity of metals

    International Nuclear Information System (INIS)

    There is increasing evidence that health effects of toxic metals differ in prevalence or are manifested differently in men and women. However, the database is small. The present work aims at evaluating gender differences in the health effects of cadmium, nickel, lead, mercury and arsenic. There is a markedly higher prevalence of nickel-induced allergy and hand eczema in women compared to men, mainly due to differences in exposure. Cadmium retention is generally higher in women than in men, and the severe cadmium-induced Itai-itai disease was mainly a woman's disease. Gender differences in susceptibility at lower exposure are uncertain, but recent data indicate that cadmium has estrogenic effects and affect female offspring. Men generally have higher blood lead levels than women. Lead accumulates in bone and increased endogenous lead exposure has been demonstrated during periods of increased bone turnover, particularly in women in pregnancy and menopause. Lead and mercury, in the form of mercury vapor and methylmercury, are easily transferred from the pregnant women to the fetus. Recent data indicate that boys are more susceptible to neurotoxic effects of lead and methylmercury following exposure early in life, while experimental data suggest that females are more susceptible to immunotoxic effects of lead. Certain gender differences in the biotransformation of arsenic by methylation have been reported, and men seem to be more affected by arsenic-related skin effect than women. Experimental studies indicate major gender differences in arsenic-induced cancer. Obviously, research on gender-related differences in health effects caused by metals needs considerable more focus in the future

  2. Acute toxicity of four heavy metals to benthic fish food organisms from the River Khan, Ujjain

    Energy Technology Data Exchange (ETDEWEB)

    Qureshi, S.A.; Saksena, A.B.; Singh, V.P.

    1980-01-01

    The acute toxicity of four heavy metals (Hg, Zn, Cd and Pb) to two benthic invertebrates viz. Tubifex tubifex and 4th instar larvae of chironomous sp. from the River Khan (Ujjain) have been determined by static bioassay experiments. Although both Tubifex tubifex and chironomous larvae have been found to be resistant to heavy metals (Hg, Zn, Cd and Pb), the experiments led to an observation that chironomous larvae are comparatively less tolerant than Tubifex tubifex. However, when the individual toxicity of heavy metals is considered it seems that the toxicity of metals is in the following order viz. Hg>Zn>Cd>Pb. The investigations reveal variation in the sensitivity of different organisms to the same toxicant and the same organisms to different toxicants.

  3. Soil Washing and Effluent Treatment for Contaminated Soil with Toxic Metals

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jung-Seok; Kwon, Man Jae [KIST Gangneung Institute, Gangneung (Korea, Republic of); Hwang, Jin-Min [Gangneung-Wonju National University, Gangneung (Korea, Republic of); Baek, Kitae [Chonbuk National University, Jeonju (Korea, Republic of)

    2013-12-15

    This study evaluated the optimal soil washing conditions for toxic metals considering the removal efficiency of toxic metals from contaminated soils as well as from soil washing effluents. In the contaminated soils, As was the major contaminant and extracted by sodium hydroxide solution better than by sulfuric acid. However, in the case of the treatment of soil washing effluents, sodium hydroxide was less effective extractant because soil organic matter extracted by sodium hydroxide prevented the solid-liquid phase separation and toxic metal removal. In the treatment of soil washing effluents with sulfuric acid, toxic metals in the effluents were mostly precipitated at the pH above 6.5. In addition, granular ferric oxide (GFO) as an adsorbent enhanced the removal of As and Pb indicating that toxic metals in the washing effluents can be removed almost completely by the use of combined adsorption-neutralization process. This study suggests that soil washing techniques for toxic metals should be optimized based on the physical and chemical properties of the contaminated soils, the nature of chemical extractant, and the removal efficiency and effectiveness of toxic metals from the soils as well as soil washing effluents.

  4. A review of toxicity and mechanisms of individual and mixtures of heavy metals in the environment.

    Science.gov (United States)

    Wu, Xiangyang; Cobbina, Samuel J; Mao, Guanghua; Xu, Hai; Zhang, Zhen; Yang, Liuqing

    2016-05-01

    The rational for the study was to review the literature on the toxicity and corresponding mechanisms associated with lead (Pb), mercury (Hg), cadmium (Cd), and arsenic (As), individually and as mixtures, in the environment. Heavy metals are ubiquitous and generally persist in the environment, enabling them to biomagnify in the food chain. Living systems most often interact with a cocktail of heavy metals in the environment. Heavy metal exposure to biological systems may lead to oxidation stress which may induce DNA damage, protein modification, lipid peroxidation, and others. In this review, the major mechanism associated with toxicities of individual metals was the generation of reactive oxygen species (ROS). Additionally, toxicities were expressed through depletion of glutathione and bonding to sulfhydryl groups of proteins. Interestingly, a metal like Pb becomes toxic to organisms through the depletion of antioxidants while Cd indirectly generates ROS by its ability to replace iron and copper. ROS generated through exposure to arsenic were associated with many modes of action, and heavy metal mixtures were found to have varied effects on organisms. Many models based on concentration addition (CA) and independent action (IA) have been introduced to help predict toxicities and mechanisms associated with metal mixtures. An integrated model which combines CA and IA was further proposed for evaluating toxicities of non-interactive mixtures. In cases where there are molecular interactions, the toxicogenomic approach was used to predict toxicities. The high-throughput toxicogenomics combines studies in genetics, genome-scale expression, cell and tissue expression, metabolite profiling, and bioinformatics. PMID:26965280

  5. Assessment of toxicity in waters due to heavy metals derived from atmospheric deposition using Vibrio fischeri.

    Science.gov (United States)

    Cukurluoglu, Sibel; Muezzinoglu, Aysen

    2013-01-01

    Water toxicity originating from the atmospheric deposition of six heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) was investigated on Vibrio fischeri activity in Izmir, Turkey. A LUMIStox® test was applied to dry and wet deposition samples and metal solutions. The inhibition levels and effective toxicity concentrations of these samples and solutions were determined. Interactive toxicity effects among the metals were investigated. When the impacts of the synthetic single heavy metal solutions were compared with each other, a toxicity ranking of Cr>Cd>Pb>Cu>Zn>Ni was obtained in order of decreasing severity. The total effective concentrations of these six metals were in the ranges of 0.074-0.221 mg/L and 0.071-0.225 mg/L for receiving aqueous solutions of dry and wet atmospheric depositions, respectively. The toxicity data showed that the wet deposition samples were 15% more toxic than the dry deposition samples. The interactive toxicity effects of the heavy metals in both dry and wet deposition samples were classified as antagonistic. High levels of heavy metals deposited in dissolved form may constitute an important input in the biochemical cycle and may have significant impacts. PMID:23030388

  6. Risk assessment of toxic heavy metals in the abandoned metal mine areas, Korea

    Science.gov (United States)

    Lee, J. S.; Chon, H. T.

    2003-04-01

    The purpose of this study is to assess the risk of adverse health effects on human exposure to toxic heavy metals influenced by past mining activities. Environmental geochemical survey was undertaken in the abandoned metal mine areas (Dongil Au-Ag-Cu-Zn mine, Okdong Cu-Pb-Zn mine, Myungbong Au-Ag mine). After appropriate sample preparation, tailings, soils, crop plants and groundwaters were analyzed for As, Cd, Cu, Pb and Zn by ICP-AES and ICP-MS. Health risk assessment of toxic heavy metals has been performed with chemical analytical data for environmental media. Arsenic and other heavy metals are highly elevated in the tailings from the Dongil mine (8,720 As mg/kg, 5.9 Cd mg/kg, 3,610 Cu mg/kg, 5,850 Pb mg/kg, 630 Zn mg/kg), but heavy metals except As from the Okdong mine (72 As mg/kg, 53.6 Cd mg/kg, 910 Cu mg/kg, 1,590 Pb mg/kg, 5,720 Zn mg/kg) and only As from the Myungbong mine (5,810 As mg/kg). These significant concentrations can impact on soils and waters around the tailing files. Also, elevated levels of As, Cd, Cu, Pb and Zn are found in agricultural soils from these mine areas. Risk assessment modeling is subdivided into main four stages, i.e. hazard identification, exposure assessment, toxicity (dose-response) assessment and risk characterization. In order to assess exposure it is necessary to calculate the average daily dose (ADD) of contaminant via the three identified pathways (soil, groundwater and food (rice grain) pathways). In dose-response assessment for non-carcinogens, reference doses (RfD) are calculated and that for carcinogens, slope factors (SF) are obtained by US-EPA IRIS database. In risk characterization, the results of toxicity assessment and exposure assessment are integrated to arrive at quantitative estimates of cancer risks and hazard quotients. Toxic (non-cancer) risks are indicated in terms of a hazard quotient (H.Q.) and this risk exists for H.Q.>1. The H.Q. values for only As from the Dongil and Myungbong mine areas are 2.1 and

  7. Assessment of airborne heavy metal pollution using plant parts and topsoil.

    Science.gov (United States)

    Serbula, Snezana M; Miljkovic, Dusanka Dj; Kovacevic, Renata M; Ilic, Ana A

    2012-02-01

    Robinia pseudoacacia L. (Fabaceae) was evaluated as a possible bioindicator of airborne heavy metal pollution, which originates from mining and pyrometallurgical copper production in Bor (Eastern Serbia). Concentrations of Cu, Zn, Pb, Cd, As and Hg were determined in different plant organs (washed/unwashed leaves, branches, roots) and topsoil of R. pseudoacacia by ICP-AES and by AAS. Sampling was carried out during 2008 at ten selected sites distributed in five zones with different levels of pollution. Concentrations of Pb, Cd and Hg did not exceeded the maximum allowed concentration (MAC) in soils at any of the sampling sites. Cu and As were present only at two sites within the MAC, whereas Zn exceeded the MAC at two sampling sites. Although present in the soil, As, Cd and Hg were below limit of detection in all parts of R. pseudoacacia. The rest of the studied elements, collected at the sites closest to the copper smelter or in the directions of the prevailing winds, were found to be at high levels. The higest Cu and Zn concentrations were detected in branches of R. pseudoacacia at the site Krivelj in the rural zone (6418.2±355.4 mg kg⁻¹ and 4699.8±320.8 mg kg⁻¹, respectively). Pb was present in similar amounts in all parts of R. pseudoacacia in the concentration ranging from 4.9 ± 0.3 mg kg⁻¹ (in washed leaves, at tourist zone) to 66.9±5.3 mg kg⁻¹ (in roots, at urban-industrial zone). According to the mobility ratio, leaves and branches of R. pseudoacacia acted as excluders of Cu, Zn and Pb, except for the branches which acted as indicators of Zn. Although As is present in high concentrations in the air and topsoil of the examined area, results show that R. pseudoacacia is not a suitable indicator of environmental pollution with As. PMID:22018546

  8. Toxicity and biosorption of metals by saccharomyces cerevisiae, amorphotheca resinae and azolla filiculoides

    OpenAIRE

    Fogarty, Robert V.

    1998-01-01

    The value of H+ efflux in assessing and understanding metal interactions with Saccharomyces cerevisiae was investigated for its potential use as a rapid means of toxicity assessment for a range of metals Toxicity decreased in the order Cu2+ > Cd2+ > Pb2+ > Co2+ > Sr2+. Toxic effects can be alleviated by external Ca2+. The effect of Cu2+ and Co2+ on S cerevisiae growth, and the intracellular localisation of Cu2+, were studied in order to gain a better understanding of their toxicity. S cer...

  9. Gas Exchange, Chlorophyll Fluorescence and Antioxidants as Bioindicators of Airborne Heavy Metal Pollution in Jeddah, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    I.A. Hassan

    2013-08-01

    Full Text Available Lettuce (Lactuca sativa L. cv. Romaine plants were exposed to different levels of urbanization in Jeddah city, Saudi Arabia. They showed different degrees of visible injury symptoms and dramatic changes in enzymatic activities as well as net photosynthetic rates (PN, variable to maximum chlorophyll fluorescence (Fv/Fm and stomatal conductance (gs.Visual symptoms of phytotoxicity of heavy metals were observed on plants grown at industrial and urban areas, where the concentrations of metals was about 36 times higher than in other sites. The decrease in chlorophyll reached 70 and 64% in plants cultivated in the industrial and urban regions, while lengths of shoots reduced by 50 and 41% in plants collected from the same locations, respectively. The reduction in chlorophyll and other physiological and biochemical parameters were correlated with the concentrations of airborne pollutants measured in the atmosphere of the locations examined. Moreover, lettuce plants cultivated in the industrial region accumulated more heavy metals than others, which can pass into the human food chain.Photosynthetic efficiency was significantly decreased and lipid peroxidation was enhanced. Antioxidant enzymes were significantly altered during exposure.The biochemical and physiological parameters measured in the present study clearly showed that they could form the basis of a plant biomarkers battery for monitoring and predicting early effects of exposure to airborne heavy metals.

  10. Review: Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops

    Institute of Scientific and Technical Information of China (English)

    ISLAM Ejaz ul; YANG Xiao-e; HE Zhen-li; MAHMOOD Qaisar

    2007-01-01

    Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants,particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely: inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil (total or bioavailable concentration) that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include: soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary

  11. Sulfur polymer cement encapsulation of RCRA toxic metals and metal oxides

    International Nuclear Information System (INIS)

    A study was conducted to determine the suitability of Sulfur Polymer Cement (SPC) encapsulation technology for the stabilization of RCRA toxic metal and metal oxide wastes. In a series of bench-scale experiments, the effects of sodium sulfide additions to the waste mixture, residence time, and temperature profile were evaluated. In addition, an effort was made to ascertain the degree to which SPC affords chemical stabilization as opposed to physical encapsulation. Experimental results have demonstrated that at the 25 wt % loading level, SPC can effectively immobilize Cr, Cr2O3, Hg, Pb, and Se to levels below regulatory limits. SPC encapsulation also has been shown to significantly reduce the leachability of other toxic compounds including PbO, PbO2, As2O3, BaO, and CdO. In addition, data has confirmed sulfide conversion of Hg, Pb, PbO, PbO2, and BaO as the product of their reaction with SPC

  12. Citrate coated silver nanoparticles change heavy metal toxicities and bioaccumulation of Daphnia magna.

    Science.gov (United States)

    Kim, Injeong; Lee, Byung-Tae; Kim, Hyun-A; Kim, Kyoung-Woong; Kim, Sang Don; Hwang, Yu-Sik

    2016-01-01

    Citrate-coated AgNPs (c-AgNPs) have negatively charged surfaces and their surface interactions with heavy metals can affect metal toxicity in aquatic environments. This study used Daphnia magna to compare the acute toxicities and bioaccumulation of As(V), Cd, and Cu when they interact with c-AgNPs. The 24-h acute toxicities of As(V) and Cu were not affected by the addition of c-AgNPs, while bioaccumulation significantly decreased in the presence of c-AgNPs. In contrast, both the 24-h acute toxicity and bioaccumulation of Cd increased in the presence of c-AgNPs. These toxicity and bioaccumulation trends can be attributed to the interactions between the AgNP surface and the heavy metals. As(V) and c-AgNPs compete by negative charge, decreasing As(V) toxicity. Copper adheres readily to c-AgNP citrate, decreasing Cu bioavailability, and thus reducing Cu toxicity and bioaccumulation. Citrate complexes with divalent cations such as Ca and Mg reduce the competition between divalent cations and Cd on biotic ligand, increasing toxicity and bioaccumulation of Cd. This study shows that surface properties determine the effect of c-AgNPs on heavy metal toxicities and bioaccumulations; hence, further studies on the effect of nanoparticle by it surface properties are warranted. PMID:26188498

  13. Bioremediation Of Heavy Metal Toxicity-With Special Reference To Chromium

    Directory of Open Access Journals (Sweden)

    Suranjana (Arora Ray and Manas Kanti Ray

    2009-12-01

    Full Text Available All metals are toxic and our bodies require special transport and handling mechanisms to keep them from harming us. The toxicity occurs in humans due to environmental pollution via soil or water contamination or due to occupational exposure. Some of these metals are useful to us in low concentrations but are highly toxic in higher concentrations. These metal toxicity cause serious morbidity and mortality. Among these heavy metals chromium toxicity can cause serious carcinogenic, genotoxic and immunotoxic effects in humans and animals. Of the two oxidative states in which chromium can be present Cr (III and Cr (VI, Cr (III is essential for the human system whereas Cr (VI has harmful effects. So, one of the ways of reducing Cr-toxicity in Cr-contaminated soil and water is to reduce soluble Cr (VI to insoluble Cr (III. This can be achieved by microbial activity and is a cost-effective and environment friendly method. Many genera of microbes like Bacillus, Enterobacter, Escherichia, Pseudomonas and also some yeasts and fungi help in bioremediation of metals and chromium-contaminated soil and water by bio-absorption and bioaccumulation of chromium. The potential of bioremediation of metal toxicity and its impact on the environment is discussed.

  14. Toxic Effects of Three Heavy Metallic Ions on Rana zhenhaiensis Tadpoles

    Institute of Scientific and Technical Information of China (English)

    Li WEI; Guohua DING; Sainan GUO; Meiling TONG; Wenjun CHEN; Jon FLANDERS; Weiwei SHAO; Zhihua LIN

    2015-01-01

    Heavy metal pollution is widespread in some areas of China and results in contamination of land, water, and air with which all living organisms interact. In this study, we used three heavy metallic ions (Cu2+, Pb2+ and Zn2+) to assess their toxicity effects on mortality, blood biomarker and growth traits (body length and body mass) of Rana zhenhaiensis tadpoles. The results showed that the toxicity levels of the three metallic ions were different when conducted with different experiment designs. For acute toxicity tests, Cu2+ was the most toxic with the highest tadpole mortality. The mortalities of tadpoles showed significant differences among the treatments at the same exposure time endpoints (24, 48, 72 and 96h). Results from repeated measures ANOVA indicated that metallic ion concentration, exposure time and their interactions significantly affected the mortalities of R. zhenhaiensis tadpoles. Also, the toxicity effects of all binary combinations of the three metallic ion treatments showed synergism. The half lethal concentrations (LC50) decreased with increasing exposure time during the experimental period, and the safe concentration (SC)values of Cu2+, Pb2+ and Zn2+ were different from each other. Combined and compared LC50 values with previous data reported, it is suggestes that the toxicity levels of metal pollution to anuran tadpoles should be species-and age-related. For blood biomarker tests, Zn2+ was the most toxic with the highest total frequencies of abnormal erythrocytic nucleus. All three metallic ions caused higher abnormal erythrocytic nucleus compared with control groups. In a chronic toxicity test, Pb2+ was the most toxic with lowest growth traits. Survival rate (except for 18 days), total body length and body mass showed significant differences among the treatments. These findings indicated that tadpoles of R. zhenhaiensis should be as a bioindicator of heavy metals pollution.

  15. Toxicity of certain heavy metals on fish in the aquatic environment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — On the earth's crust there are 59 heavy metals of which 17 are considered toxic to biological communities. Here in Alaska, we have thus far considered the following...

  16. Occupational and Community Exposures to Toxic Metals: Lead, Cadmium, Mercury and Arsenic

    OpenAIRE

    Landrigan, Philip J.

    1982-01-01

    Lead, cadmium, mercury and arsenic are widely dispersed in the environment. Adults are primarily exposed to these contaminants in the workplace. Children may be exposed to toxic metals from numerous sources, including contaminated air, water, soil and food.

  17. Portable Sensor for Rapid In Situ Measurement of Trace Toxic Metals in Water Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of a sensor to detect select trace toxic heavy metals (Ag, Cd, Mn, Ni, and Zn) in water is proposed. Using an automatic side-stream sampling technique,...

  18. Removal and recovery of toxic metal ions from aqueous waste sites using polymer pendant ligands

    Energy Technology Data Exchange (ETDEWEB)

    Fish, D. [Lawrence Berkeley National Lab., CA (United States)

    1996-10-01

    The purpose of this project is to investigate the use of polymer pendant ligand technology to remove and recover toxic metal ions from DOE aqueous waste sites. Polymer pendant lgiands are organic ligands, anchored to crosslinked, modified divinylbenzene-polystyrene beads, that can selectively complex metal ions. The metal ion removal step usually occurs through a complexation or ion exchange phenomena, thus recovery of the metal ions and reuse of the beads is readily accomplished.

  19. Metal and pharmaceutical mixtures: Is ion loss the mechanism underlying acute toxicity and widespread additive toxicity in zebrafish?

    Energy Technology Data Exchange (ETDEWEB)

    Alsop, Derek, E-mail: alsopde@mcmaster.ca; Wood, Chris M.

    2013-09-15

    Highlights: •Zebrafish larvae were used to test the acute toxicity of contaminant mixtures. •Interactions were observed between metals, ammonia and pharmaceuticals. •Larval Na{sup +} loss was observed with exposure to all acutely toxic contaminants tested. •Water quality criteria should recognize the toxic interactions between contaminants. -- Abstract: The acute toxicities and mechanisms of action of a variety of environmental contaminants were examined using zebrafish larvae (Danio rerio; 4–8 days post fertilization). Toxic interactions were observed between metals. For example, the addition of a sublethal level of nickel (15% of the LC{sub 50}, one third of the LC{sub 01}) to all copper treatments decreased the copper 96 h LC{sub 50} by 58%, while sublethal copper exposure (6% of the copper LC{sub 50}, 13% of the LC{sub 01}) decreased the cadmium 96 h LC{sub 50} by 47%. Two predictive models were assessed, the concentration addition (CA) model, which assumes similar mechanisms of action, and the independent action (IA) model, which assumes different mechanisms of action. Quantitative comparisons indicated the CA model performed better than the IA model; the latter tended to underestimate combined toxicity to a greater extent. The effects of mixtures with nickel or ammonia were typically additive, while mixtures with copper or cadmium were typically greater than additive. Larvae exposed to cadmium, copper or nickel experienced whole body ion loss. Decreases were greatest for Na{sup +} followed by K{sup +} (as high as 19% and 9%, respectively, in 24 h). Additive toxicity between copper and other pharmaceutical compounds such as fluoxetine (Prozac™), β-naphthoflavone, estrogen and 17α-ethinylestradiol were also observed. Similar to metals, acutely toxic concentrations of fluoxetine, β-naphthoflavone and ammonia all decreased whole body Na{sup +} and K{sup +}. Overall, whole body Na{sup +} loss showed the greatest correlation with mortality across a

  20. Fabrication of Metal and Metal Oxide Nanoparticles by Algae and their Toxic Effects.

    Science.gov (United States)

    Siddiqi, Khwaja Salahuddin; Husen, Azamal

    2016-12-01

    Of all the aquatic organisms, algae are a good source of biomolecules. Since algae contain pigments, proteins, carbohydrates, fats, nucleic acids and secondary metabolites such as alkaloids, some aromatic compounds, macrolides, peptides and terpenes, they act as reducing agents to produce nanoparticles from metal salts without producing any toxic by-product. Once the algal biomolecules are identified, the nanoparticles of desired shape or size may be fabricated. The metal and metal oxide nanoparticles thus synthesized have been investigated for their antimicrobial activity against several gram-positive and gram-negative bacterial strains and fungi. Their dimension is controlled by temperature, incubation time, pH and concentration of the solution. In this review, we have attempted to update the procedure of nanoparticle synthesis from algae, their characterization by UV-vis, Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, x-ray diffraction, energy-dispersive x-ray spectroscopy, dynamic light scattering and application in cutting-edge areas. PMID:27530743

  1. Multidrug-Resistance and Toxic Metal Tolerance of Medically Important Bacteria Isolated from an Aquaculture System

    OpenAIRE

    Resende, Juliana Alves; Silva, Vânia L.; Fontes, Cláudia Oliveira; Souza-Filho, Job Alves; de Oliveira, Tamara Lopes Rocha; Coelho, Cíntia Marques; César, Dionéia Evangelista; Diniz, Cláudio Galuppo

    2012-01-01

    The use of antimicrobials and toxic metals should be considered carefully in aquaculture and surrounding environments. We aimed to evaluate medically relevant bacteria in an aquaculture system and their susceptibility to antimicrobials and toxic metals. Selective cultures for enterobacteria (ENT), non-fermenting Gram-negative rods (NFR) and Gram-positive cocci (GPC) were obtained from water samples collected in two different year seasons. The isolated bacteria were biochemically identified an...

  2. Soil Invertebrates As Bio-Monitors of Toxic Metals Pollution in Impacted Soils

    OpenAIRE

    Imaobong I. Udousoro; I. U. Umoren; J. M. Izuagie; C. U. Ikpo; S. F. Ngeri; E. S. Shaibu

    2015-01-01

    The bio-indicator potentials of two invertebrate species, Eudrilus eugeniae (earthworm) and Pachybolus ligulatus (millipede) in toxic metals impacted soils in Akwa Ibom State, in the Niger Delta region of Nigeria were assessed. The study involved collection of Eudrilus eugeniae and Pachybolus ligulatus, and their site soil samples from different impacted and non-impacted soils in ten locations spread over four Local Government Areas. Toxic metals (Pb, Fe, Zn, Ni and Cd) in soils and in the bi...

  3. ATMOSPHERIC DEPOSITION OF TOXIC METALS TO LAKE MICHIGAN: PRELIMINARY ANNUAL MODEL CALCULATIONS

    Science.gov (United States)

    Concern is growing for the environmental water quality of the Great Lakes. tmospheric deposition of toxic substances is recognized as a major pathway of contaminants to the water medium. o estimate the annual atmospheric loadings of five toxic metals -- arsenic (As), cadmium (Cd)...

  4. A general mechanism for intracellular toxicity of metal-containing nanoparticles

    KAUST Repository

    Sabella, Stefania

    2014-04-09

    The assessment of the risks exerted by nanoparticles is a key challenge for academic, industrial, and regulatory communities worldwide. Experimental evidence points towards significant toxicity for a range of nanoparticles both in vitro and in vivo. Worldwide efforts aim at uncovering the underlying mechanisms for this toxicity. Here, we show that the intracellular ion release elicited by the acidic conditions of the lysosomal cellular compartment-where particles are abundantly internalized-is responsible for the cascading events associated with nanoparticles-induced intracellular toxicity. We call this mechanism a "lysosome-enhanced Trojan horse effect" since, in the case of nanoparticles, the protective cellular machinery designed to degrade foreign objects is actually responsible for their toxicity. To test our hypothesis, we compare the toxicity of similar gold particles whose main difference is in the internalization pathways. We show that particles known to pass directly through cell membranes become more toxic when modified so as to be mostly internalized by endocytosis. Furthermore, using experiments with chelating and lysosomotropic agents, we found that the toxicity mechanism for different metal containing NPs (such as metallic, metal oxide, and semiconductor NPs) is mainly associated with the release of the corresponding toxic ions. Finally, we show that particles unable to release toxic ions (such as stably coated NPs, or diamond and silica NPs) are not harmful to intracellular environments. The Royal Society of Chemistry 2014.

  5. Toxicity Assessment of Sediments with Natural Anomalous Concentrations in Heavy Metals by the Use of Bioassay

    Directory of Open Access Journals (Sweden)

    Francisco Martín

    2010-01-01

    Full Text Available The potential toxicity in riverbed sediments was assessed with a bioassay using the bioluminescent bacteria Vibrio fischeri. The selected area was characterized by the presence of ultramafic rocks (peridotites, and the sediments had high values in Ni, Cr, and Co. For the toxicity bioassay with Vibrio fischeri, water-soluble forms were used. The results indicated that most of the samples had a very low degree of toxicity, with 10% of reduction in luminescence in relation to the control; meanwhile 25% of the samples had a moderate degree of toxicity with a reduction in luminescence between 13 and 21% in relation to the control. The toxicity index correlated significantly with the concentrations of Ni and Cr in the water extracts. This toxicity bioassay was proved to be a sensitive and useful tool to detect potential toxicity in solutions, even with anomalous concentrations in heavy metals of natural origin.

  6. Lac Dufault sediment core trace metal distribution, bioavailability and toxicity to Hyalella azteca

    International Nuclear Information System (INIS)

    To determine changes in metal distribution, bioavailability and toxicity with sediment depth, two 20-cm-long replicate cores were collected from a lake historically subjected to the influence of metal mining and smelting activity. The vertical distribution of Pb, Cd and Cu in sediment was similar for all three metals, with the surface layers showing enrichment and the deeper (pre-industrial) layers showing lower concentrations. Toxicity of each sediment core section was determined in laboratory tests with the freshwater amphipod Hyalella azteca. Bioavailable metal in each sediment slice was estimated from metal concentrations in overlying water in these toxicity tests and, for Cd, also from metal bioaccumulation. The profile for Cd in tissue was comparable to Cd in sediment and overlying water, but relative Cd bioavailability from sediment increased with sediment depth. Survival increased with increasing sediment depth, suggesting that surface sediments were probably less or non-toxic before industrialization. - Toxicity and bioaccumulation tests with sediment cores provide more information on biological effects of metals than surface sediment tests

  7. Lac Dufault sediment core trace metal distribution, bioavailability and toxicity to Hyalella azteca

    Energy Technology Data Exchange (ETDEWEB)

    Nowierski, Monica [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Dixon, D. George [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Borgmann, Uwe [National Water Research Institute, Canada Centre for Inland Waters, 867 Lakeshore Road, PO Box 5050, Burlington, Ontario L7R 4A6 (Canada)]. E-mail: uwe.borgmann@ec.gc.ca

    2006-02-15

    To determine changes in metal distribution, bioavailability and toxicity with sediment depth, two 20-cm-long replicate cores were collected from a lake historically subjected to the influence of metal mining and smelting activity. The vertical distribution of Pb, Cd and Cu in sediment was similar for all three metals, with the surface layers showing enrichment and the deeper (pre-industrial) layers showing lower concentrations. Toxicity of each sediment core section was determined in laboratory tests with the freshwater amphipod Hyalella azteca. Bioavailable metal in each sediment slice was estimated from metal concentrations in overlying water in these toxicity tests and, for Cd, also from metal bioaccumulation. The profile for Cd in tissue was comparable to Cd in sediment and overlying water, but relative Cd bioavailability from sediment increased with sediment depth. Survival increased with increasing sediment depth, suggesting that surface sediments were probably less or non-toxic before industrialization. - Toxicity and bioaccumulation tests with sediment cores provide more information on biological effects of metals than surface sediment tests.

  8. Contamination, toxicity and speciation of heavy metals in an industrialized urban river: Implications for the dispersal of heavy metals.

    Science.gov (United States)

    Wu, Qihang; Zhou, Haichao; Tam, Nora F Y; Tian, Yu; Tan, Yang; Zhou, Song; Li, Qing; Chen, Yongheng; Leung, Jonathan Y S

    2016-03-15

    Urban rivers are often utilized by the local residents as water source, but they can be polluted by heavy metals due to industrialization. Here, the concentrations, toxicity, speciation and vertical profiles of heavy metals in sediment were examined to evaluate their impact, dispersal and temporal variation in Dongbao River. Results showed that the sediment in the industrialized areas was seriously contaminated with Cr, Cu and Ni which posed acute toxicity. Heavy metals, except Cr and Pb, were mainly associated with non-residual fractions, indicating their high mobility and bioavailability. The non-industrialized areas were also seriously contaminated, suggesting the dispersal of heavy metals along the river. The surface sediment could be more contaminated than the deep sediment, indicating the recent pollution events. Overall, when the point sources are not properly regulated, intense industrialization can cause both serious contamination and dispersal of heavy metals, which have far-reaching consequences in public health and environment. PMID:26856647

  9. Genetic basis and importance of metal resistant genes in bacteria for bioremediation of contaminated environments with toxic metal pollutants.

    Science.gov (United States)

    Das, Surajit; Dash, Hirak R; Chakraborty, Jaya

    2016-04-01

    Metal pollution is one of the most persistent and complex environmental issues, causing threat to the ecosystem and human health. On exposure to several toxic metals such as arsenic, cadmium, chromium, copper, lead, and mercury, several bacteria has evolved with many metal-resistant genes as a means of their adaptation. These genes can be further exploited for bioremediation of the metal-contaminated environments. Many operon-clustered metal-resistant genes such as cadB, chrA, copAB, pbrA, merA, and NiCoT have been reported in bacterial systems for cadmium, chromium, copper, lead, mercury, and nickel resistance and detoxification, respectively. The field of environmental bioremediation has been ameliorated by exploiting diverse bacterial detoxification genes. Genetic engineering integrated with bioremediation assists in manipulation of bacterial genome which can enhance toxic metal detoxification that is not usually performed by normal bacteria. These techniques include genetic engineering with single genes or operons, pathway construction, and alternations of the sequences of existing genes. However, numerous facets of bacterial novel metal-resistant genes are yet to be explored for application in microbial bioremediation practices. This review describes the role of bacteria and their adaptive mechanisms for toxic metal detoxification and restoration of contaminated sites. PMID:26860944

  10. Toxicity of Transition Metal Oxide Nanoparticles: Recent Insights from in vitro Studies

    Directory of Open Access Journals (Sweden)

    Robert S. Aronstam

    2010-10-01

    Full Text Available Nanotechnology has evolved to play a prominent role in our economy. Increased use of nanomaterials poses potential human health risk. It is therefore critical to understand the nature and origin of the toxicity imposed by nanomaterials (nanotoxicity. In this article we review the toxicity of the transition metal oxides in the 4th period that are widely used in industry and biotechnology. Nanoparticle toxicity is compellingly related to oxidative stress and alteration of calcium homeostasis, gene expression, pro-inflammatory responses, and cellular signaling events. The precise physicochemical properties that dictate the toxicity of nanoparticles have yet to be defined, but may include element-specific surface catalytic activity (e.g., metallic, semiconducting properties, nanoparticle uptake, or nanoparticle dissolution. These in vitro studies substantially advance our understanding in mechanisms of toxicity, which may lead to safer design of nanomaterials.

  11. Metals and cocoa products: a study on characterization of toxic and essential metals in chocolates (abstract)

    International Nuclear Information System (INIS)

    In this study, a sophisticated analytical technique, atomic absorption spectrometer (both with FAAS and GFAAS modes of atomization), was used for analyzing essential and toxic metal (Fe, Mn, Cu, Zn, Ni, Pb and Cd) contents in 32 commonly consumed cocoa products (chocolates) prepared by different national and multinational companies. Significant differences were observed between the micro element contents of the 32 varieties (P < 0.01). The risk posed by the quantity of heavy metals lead, cadmium and nickel present in cocoa products (chocolates) is of serious apprehension and weekly intake was calculated. The Concentration of Pb and Cd in cocoa powder is found to be highest 492 and 197 mu g/L followed by cocoa based chocolates 306 and 46.8 mu g/L, sugar based chocolates 209.8 and 40.3 mu g/L whereas it is least in milk based chocolates samples 88.3 and 33 mu g/L respectively. The concentration of Pb and Cd was found below the provisional tolerable weekly intake defined by FAO/WHO. All essential elements were assessed for their weekly intake with the dietary reference intakes. In order to validate our results, certified reference material (Wheat flour 1589, Milk powder A-11 and Milk Powder A-8) were analyzed for Fe, Mn, Cu, Zn, Ni, Pb and Cd levels. Determined concentrations were quite in good agreement with certified levels. Data was interpreted through cluster analysis and pattern recognition. (author)

  12. Toxicity and metal speciation in acid mine drainage treated by passive bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Neculita, C.M.; Vigneaul, B.; Zagury, G.J. [Ecole Polytechnic, Montreal, PQ (Canada)

    2008-08-15

    Sulfate-reducing passive bioreactors treat acid mine drainage (AMD) by increasing its pH and alkalinity and by removing metals as metal sulfide precipitates. In addition to discharge limits based on physicochemical parameters, however, treated effluent is required to be nontoxic. Acute and sublethal toxicity was assessed for effluent from 3.5-L column bioreactors filled with mixtures of natural organic carbon sources and operated at different hydraulic retention times (HRTs) for the treatment of a highly contaminated AMD. Effluent was first tested for acute (Daphnia magna and Oncorhynchus mykiss) and sublethal (Pseudokirchneriella subcapitata, Ceriodaphnia dabia, and Lemna minor) toxicity. Acute toxicity was observed for D. magna, and a toxicity identification evaluation (TIE) procedure was then performed to identify potential toxicants. Finally, metal speciation in the effluent was determined using ultrafiltration and geochemical modeling for the interpretation of the toxicity results. The 10-d HRT effluent was nonacutely lethal for 0. mykiss but acutely lethal for D. magna. The toxicity to D. magna, however, was removed by 2 h of aeration, and the TIE procedure suggested iron as a cause of toxicity. Sublethal toxicity of the 10-d HRT effluent was observed for all test species, but it was reduced compared to the raw AMD and to a 7.3-d HRT effluent. Data regarding metal speciation indicated instability of both effluents during aeration and were consistent with the toxicity being caused by iron. Column bioreactors in operation for more than nine months efficiently improved the physicochemical quality of highly contaminated AMD at different HRTs.

  13. Treatment of tunnel wash waters - experiments with organic sorbent materials. Part Ⅱ: Removal of toxic metals

    Institute of Scientific and Technical Information of China (English)

    PARUCH Adam M; ROSETH Roger

    2008-01-01

    In the first part of the article, the column and the bag experiments concerning removal of polycyclic aromatic hydrocarbons (PAHs) and nonpolar oil (NPO) from tunnel wash waters using organic sorbent materials have been described. This part presents the results of removal of toxic metals. The metals of concern (Al, As, Cd, Cr, Cu, Fe, Pb, Mo, Ni, and Zn) were selected based on the priority toxicant pollutants defined in surface water quality criteria. Concentrations of these metals in the collected effluents varied more than the concentrations of PAHs and NPO, and thus only metal contents were considered for statistical analyses. These analyses determined significant differences (P<0.05, P<0.01, and P<0.001) between the mean metal concentrations in the column effluents and those in applied wash water of road tunnel. The results obtained during both experiments revealed that the organic sorbents, and in particular their combination, removed toxic metals more effectively from wash water of road tunnel than from wash water of tunnel electrostatic filters. Among the investigated toxicants, Al and Fe showed the highest levels of reduction in the column experiment, 99.7% and 99.6%, respectively. The lowest reduction levels of 66.0% and 76.2% were found for Pb and Mo, respectively. The results of the bag experiment showed that even one day treatment of wash waters from tunnel electrostatic filters could reduce concentration of some toxicants by more than 70% (Al and Fe) and 80% (Cu).

  14. Metal Oxide Nanomaterial QNAR Models: Available Structural Descriptors and Understanding of Toxicity Mechanisms

    Directory of Open Access Journals (Sweden)

    Jiali Ying

    2015-10-01

    Full Text Available Metal oxide nanomaterials are widely used in various areas; however, the divergent published toxicology data makes it difficult to determine whether there is a risk associated with exposure to metal oxide nanomaterials. The application of quantitative structure activity relationship (QSAR modeling in metal oxide nanomaterials toxicity studies can reduce the need for time-consuming and resource-intensive nanotoxicity tests. The nanostructure and inorganic composition of metal oxide nanomaterials makes this approach different from classical QSAR study; this review lists and classifies some structural descriptors, such as size, cation charge, and band gap energy, in recent metal oxide nanomaterials quantitative nanostructure activity relationship (QNAR studies and discusses the mechanism of metal oxide nanomaterials toxicity based on these descriptors and traditional nanotoxicity tests.

  15. Modification of the in vitro hydra assay developmental toxicity screen for evaluation of airborne toxicants: Assessment of ammonium perchlorate and vapor expos. Final report, 15 December 1995-30 September 1996

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, R.E.

    1996-12-01

    When the Combat Exclusion Law was repealed, military women`s duties were expanded to include duties that formally were exclusively performed by men. These military women are occupationally exposed to chemicals, including airborne toxicants, for which no developmental or reproductive toxicity testing has been performed. The reproductive toxicity of these chemical compounds needs serious consideration so that military women can continue to perform their mission responsibilities and remain healthy. An in vitro developmental toxicity screen was performed to determine the developmental hazard index (A/D ratio) for ammonium perchlorate (AP), tricresyl phosphate vapor phase lubricant (TCP), and diethyleneglycol monomethylether (DGME) using the hydra assay. The screen employed exposing both adult Hydra attenuate and `artificial embryos` composed of disassociated hydra cells to these military compounds to investigate potential developmental toxicity. AID ratios of 1.71, <0.055, and 1.75, obtained for AP, TCP, and DGME, respectively, would indicate that these military compounds should not be considered primary developmental toxins in the context of this assay.

  16. Scoping analysis of toxic metal performance in DOE low-level waste disposal facilities

    International Nuclear Information System (INIS)

    This study provides a scoping safety assessment for disposal of toxic metals contained in Department of Energy (DOE) mixed low-level waste (MLLW) at six DOE sites that currently have low-level waste (LLW) disposal facilities--Savannah River Site, Oak Ridge Reservation, Los Alamos National Laboratory, Hanford Reservation, Nevada Test Site, and Idaho National Engineering Laboratory. The study has focused on the groundwater contaminant pathway, which is considered to be the dominant human exposure pathway from shallow land MLLW disposal. A simple and conservative transport analysis has been performed using site hydrological data to calculate site-specific ''permissible'' concentrations of toxic metals in grout-immobilized waste. These concentrations are calculated such that, when toxic metals are leached from the disposal facility by infiltrating water and attenuated in local ground-water system the toxic metal concentrations in groundwater below the disposal facility do not exceed the Maximum Contaminant Levels as stated in the National Primary Drinking Water Regulation. The analysis shows that and sites allow about I00 times higher toxic metal concentrations in stabilized waste leachate than humid sites. From the limited available data on toxic metal concentrations in DOE MLLW, a margin of protection appears to exist in most cases when stabilized wastes containing toxic metals are disposed of at the DOE sites under analysis. Possible exceptions to this conclusion are arsenic, chromium selenium, and mercury when disposed of at some humid sites such as the Oak Ridge Reservation. This analysis also demonstrates that the US Environmental Protection Agency's prescriptive regulatory approach that defines rigid waste treatment standards does not inherently account for the variety of disposal environments encountered nationwide and may result in either underprotection of groundwater resources (at humid sites) or an excessive margin of protection (at and sites)

  17. Potential risks of metal toxicity in contaminated sediments of Deule river in Northern France

    International Nuclear Information System (INIS)

    Research highlights: → A historical environmental pollution is evidenced with reference to background levels. → Sedimentary trace metals partitioning is examined under undisturbed conditions. → Anoxia and diagenetic processes induce geochemical and mineralogical variabilities. → Do metals present in particles and pore waters exhibit a potential toxicity risk? → Behaviour of binding fractions contributes to trace metals scavenging. - Abstract: The aim of this paper was to evaluate the potential sediment cumulative damage and toxicity due to metal contamination in a polluted zone of Deule river (in northern France) from nearby two smelters. Metal-enrichment factors and geoaccumulation indices measured with sediment depth revealed that - compared to background levels either in local reference soils or in world rivers sediments/suspended particulate matter - Cd contributed to the highest pollution levels, followed by Zn, Pb and to a much lesser extent Cu and Ni. A comparison of the vertical distribution of AVS (acid volatile sulfides), SEM (simultaneously extracted metals), TMC (total metal concentrations), TOC (total organic carbon) and interstitial water-metal concentrations in the sediment allowed us to highlight the extent of toxicity caused by Cd, Pb, Zn, Ni and Cu and to raise the possibility of their association with certain geochemical phases. To assess the actual environmental impacts of these metals in Deule river, numerical sediment quality guidelines were further used in the present work. Sedimentary Pb, Zn, and Cd contents largely exceeded PEC (probable effect concentration) values reported as consensus-based sediment quality guidelines for freshwater ecosystems. As for risks of toxicity from pore waters, metal concentrations reached their maxima at the surficial layers of the sediment (1-3 cm) and IWCTU (Interstitial Water Criteria Toxicity Unit) observed for Pb and to a lesser extent Cd, violated the corresponding water quality data recommended

  18. Thermal treatment of toxic metals of industrial hazardous wastes with fly ash and clay

    International Nuclear Information System (INIS)

    Waste generated from galvanizing and metal finishing processes is considered to be a hazardous due to the presence of toxic metals like Pb, Cu, Cr, Zn, etc. Thermal treatment of such types of wastes in the presence of clay and fly ash can immobilizes their toxic metals to a maximum level. After treatment solidified mass can be utilized in construction or disposed off through land fillings without susceptibility of re-mobilization of toxic metals. In the present investigation locally available clay and fly ash of particular thermal power plant were used as additives for thermal treatment of both of the wastes in their different proportions at 850, 900 and 950 deg. C. Observed results indicated that heating temperature to be a key factor in the immobilization of toxic metals of the waste. It was noticed that the leachability of metals of the waste reduces to a negligible level after heating at 950 deg. C. Thermally treated solidified specimen of 10% waste and remaining clay have shown comparatively a higher compressive strength than clay fired bricks used in building construction. Though, thermally heated specimens made of galvanizing waste have shown much better strength than specimen made of metal finishing waste. The lechability of toxic metals like Cr, Cu, Pb and Zn became far below from their regulatory threshold after heating at 950 deg. C. Addition of fly ash did not show any improvement either in engineering property or in leachability of metals from the solidified mass. X-ray diffraction (XRD) analysis of the solidified product confirmed the presence of mixed phases of oxides of metals

  19. Phytotoxicity of trace metals in spiked and field-contaminated soils: Linking soil-extractable metals with toxicity.

    Science.gov (United States)

    Hamels, Fanny; Malevé, Jasmina; Sonnet, Philippe; Kleja, Dan Berggren; Smolders, Erik

    2014-11-01

    Soil tests have been widely developed to predict trace metal uptake by plants. The prediction of metal toxicity, however, has rarely been tested. The present study was set up to compare 8 established soil tests for diagnosing phytotoxicity in contaminated soils. Nine soils contaminated with Zn or Cu by metal mining, smelting, or processing were collected. Uncontaminated reference soils with similar soil properties were sampled, and series of increasing contamination were created by mixing each with the corresponding soil. In addition, each reference soil was spiked with either ZnCl2 or CuCl2 at several concentrations. Total metal toxicity to barley seedling growth in the field-contaminated soils was up to 30 times lower than that in corresponding spiked soils. Total metal (aqua regia-soluble) toxicity thresholds of 50% effective concentrations (EC50) varied by factors up to 260 (Zn) or 6 (Cu) among soils. For Zn, variations in EC50 thresholds decreased as aqua regia > 0.43 M HNO3  > 0.05 M ethylenediamine tetraacetic acid (EDTA) > 1 M NH4 NO3  > cobaltihexamine > diffusive gradients in thin films (DGT) > 0.001 M CaCl2 , suggesting that the last extraction is the most robust phytotoxicity index for Zn. The EDTA extraction was the most robust for Cu-contaminated soils. The isotopically exchangeable fraction of the total soil metal in the field-contaminated soils markedly explained the lower toxicity compared with spiked soils. The isotope exchange method can be used to translate soil metal limits derived from soils spiked with metal salts to site-specific soil metal limits. PMID:25053440

  20. Characterization of trace metals in airborne carbonaceous aerosols by single-particle EDX – Scanning Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Pietrodangelo A.

    2013-04-01

    Full Text Available The presence of fine and ultrafine metal particles has been evidenced in size segregated airborne carbonaceous aerosols collected at one industrial and two background (urban and rural sites during an extended field campaign in Central Italy. Analysis of the backscattered electrons (BSE by SEM – EDX demonstrated an effective potential in evidencing main structural features of the metal content in identified carbon aerosols. Many observed ultrafine metal particles appear embedded in the skeleton of carbonaceous individual particles and aggregates in the coarse fraction, while the same is not evident in the case of mixed carbon-sulphates aerosol that has been detected in the submicron size. These carbon-sulphates formations include indeed nano-sized metal particles that appear physically combined but not embedded. Also, larger metal particles (ranging around 1 μm physical size were observed close to carbon materials, but not included in their structure. Main compositional differences of metal particles with size segregation could be evidenced by energy – dispersive X ray spectrometry (EDX. Larger particles are mainly rich in Fe, frequently in presence of Mn, Cu, Cr and Zn in variable proportions; either oxidized or elemental metals were detected. On the other hand, ultrafine particles associated with carbon–sulphates aerosol are enriched in Pb and Zn, although the presence of other trace elements not detectable by SEM – EDX technique cannot be excluded. Moreover, Ce-enriched ultrafine particles were clearly determined in cenospheres. Conversely, inclusion of fine and ultrafine metal particles was rarely or not observed in soot aggregates.

  1. Natural and active chemical remediation of toxic metals and radionuclides in the aquatic environment

    International Nuclear Information System (INIS)

    The focus of this research is the non-biological, chemical remediation of toxic heavy metals and radionuclides in aquatic environments. This Tulane/Xavier group includes researchers from Chemistry, Chemical Engineering, and Geology. Active methods using novel zeolites and ion exchange membranes are currently being evaluated for use in removing heavy metals from natural waters. In addition, field and laboratory studies of metal ion exchange reactions and competitive, heavy metal adsorption on clay substrates are underway to determine sediment metal sequestering capacity. A summary of progress to date and future work is presented

  2. Influences of sediment geochemistry on metal accumulation rates and toxicity in the aquatic oligochaete Tubifex tubifex.

    Science.gov (United States)

    Méndez-Fernández, Leire; De Jonge, Maarten; Bervoets, Lieven

    2014-12-01

    Metal bioaccumulation and toxicity in the aquatic oligochaete Tubifex tubifex exposed to three metal-contaminated field-sediments was studied in order to assess whether sediment-geochemistry (AVS, TOC) plays a major role in influencing these parameters, and to assess if the biodynamic concept can be used to explain observed effects in T. tubifex tissue residues and/or toxicity. An active autotomy promotion was observed in three studied sediments at different time points and reproduction impairment could be inferred in T. tubifex exposed to two of the tested sites after 28 days. The present study showed that sediment metal concentration and tissue residues followed significant regression models for four essential metals (Cu, Co, Ni and Zn) and one non-essential metal (Pb). Organic content normalization for As also showed a significant relationship with As tissue residue. Porewater was also revealed to be an important source of metal uptake for essential metals (e.g. Cu, Ni and Zn) and for As, but AVS content was not relevant for metal uptake in T. tubifex in studied sediments. Under the biodynamic concept, it was shown that influx rate from food (IF, sediment ingestion) in T. tubifex, in a range of sediment geochemistry, was able to predict metal bioaccumulation, especially of the essential metals Cu, Ni and Zn, and for the non-essential metal Pb. Additionally, IF appeared to be a better predictor for metal bioaccumulation in T. tubifex compared to sediment geochemistry normalization. PMID:25456225

  3. Toxicity of metals to roots of cowpea in relation to their binding strength.

    Science.gov (United States)

    Kopittke, Peter M; Blamey, F Pax C; McKenna, Brigid A; Wang, Peng; Menzies, Neal W

    2011-08-01

    Metal phytotoxicity is important in both environmental and agricultural systems. A solution culture study examined the toxicity of 26 metals to roots of cowpea (Vigna unguiculata (L.) Walp.); new data were collected for 15 metals and published data for 11 metals. Metal toxicity, calculated as causing a 50% reduction in root elongation rate, was determined based on either the measured concentration in the bulk solution (EC50(b)) or the calculated activity at the outer surface of the plasma membrane (EA50(0)°). The EC50(b) values ranged from 0.007 µM for Tl to 98,000 µM for K, with the order of rhizotoxicity to cowpea, from most to least toxic, being Tl = Ag > Cu > Hg = Ni = Ga = Ru = In > Sc = Cd = Gd = La = Co = Cs = Pb > Zn = Al = H > Mn > Ba = Sr > Li > Mg > Ca = Na > K. The EA50(0)° values suggest that the binding of metals to hard ligands is an important, general, nonspecific mechanism of toxicity, a hypothesis supported by the similar toxicity symptoms to roots of cowpea by many metals. However, additional mechanisms, such as strong binding to soft ligands, substantially increase rhizotoxicity of some metals, especially Tl, Ag, and Cs. Besides direct toxic effects, osmotic effects or reduced activity of Ca(2+) at the outer surface of the root plasma membrane (and resultant Ca deficiency) may decrease short-term root growth. PMID:21538487

  4. Dietary toxicity of field-contaminated invertebrates to marine fish: effects of metal doses and subcellular metal distribution.

    Science.gov (United States)

    Dang, Fei; Rainbow, Philip S; Wang, Wen-Xiong

    2012-09-15

    There is growing awareness of the toxicological effects of metal-contaminated invertebrate diets on the health of fish populations in metal-contaminated habitats, yet the mechanisms underlying metal bioaccumulation and toxicity are complex. In the present study, marine fish Terapon jurbua terepon were fed a commercial diet supplemented with specimens of the polychaete Nereis diversicolor or the clam Scrobicularia plana, collected from four metal-impacted estuaries (Tavy, Restronguet Creek, West Looe, Gannel) in southwest England, as environmentally realistic metal sources. A comparative toxicological evaluation of both invertebrates showed that fish fed S. plana for 21 d exhibited evident mortality compared to those fed N. diversicolor. Furthermore, a spatial effect on mortality was observed. Differences in metal doses rather than subcellular metal distributions between N. diversicolor and S. plana appeared to be the cause of such different mortalities. Partial least squares regression was used to evaluate the statistical relationship between multiple-metal doses and fish mortality, revealing that Pb, Fe, Cd and Zn in field-collected invertebrates co-varied most strongly with the observed mortality. This study provides a step toward exploring the underlying mechanism of dietary toxicity and identifying the potential causality in complex metal mixture exposures in the field. PMID:22579710

  5. Migration of Toxic Metals from Ceramic Food Packaging Materials into Acid Food Simulants

    Directory of Open Access Journals (Sweden)

    Zhanhua Dong

    2014-01-01

    Full Text Available Long-term extraction experiments were carried out on glazed tile specimens with 4 and 10% (v/v acetic acid, 1% (w/v citric acid, and 1% (v/v lactic acid solution in three temperature conditions (20, 40, and 60°C to investigate the effect of temperature and pH value on extraction of lead, cobalt, nickel, and zinc from ceramic food packaging materials and to study the extraction kinetics of toxic metals. Results showed that except at 60°C the amount of extraction of lead, cobalt, nickel, and zinc had linear dependence on time at longer times and removal of these toxic metals under other conditions increased linearly with the square root of the time, indicating a diffusion-controlled process. The amount of these toxic metals leached out from ceramic food packaging materials into the leachate, and the leaching rate increased with temperature and decreased with pH value of the food simulants. In addition, among these four toxic metals lead was the least leachable element, and nickel was the most leachable one. Disagreement between the ratios of the oxide of lead, cobalt, nickel, and zinc in the glaze and their release in the leachate suggested that extraction of these toxic metals was an incongruent dissolution process.

  6. The use of nuclear and related techniques for the studies of possible health impact of airborne particulate matter in a metal industry

    International Nuclear Information System (INIS)

    Possible health effects of airborne particulate matter in the workplace were investigated by searching the correlation between the enriched elements in the airborne particulate matter and elemental levels of blood, nail and hair of workers in a metal industry. Blood, hair and nail samples were collected from 58 workers of a metal industry, and airborne particulate matter (APM) samples were collected from halls or buildings where the workers were carrying out their work. The workers were subjected to medical examination comprising medical history recording, physical examination and routine blood check. The collected biological and APM samples were analysed for trace elements by neutron activation analysis. A general tendency of higher zinc levels in serum and erythrocytes in workers than in healthy individuals (controls) was observed. However, more examinations on a larger population need to be carried out in order to confirm this finding on a statistically sound basis. (author)

  7. Toxicity effects on metal sequestration by microbially-induced carbonate precipitation.

    Science.gov (United States)

    Mugwar, Ahmed J; Harbottle, Michael J

    2016-08-15

    Biological precipitation of metallic contaminants has been explored as a remedial technology for contaminated groundwater systems. However, metal toxicity and availability limit the activity and remedial potential of bacteria. We report the ability of a bacterium, Sporosarcina pasteurii, to remove metals in aerobic aqueous systems through carbonate formation. Its ability to survive and grow in increasingly concentrated aqueous solutions of zinc, cadmium, lead and copper is explored, with and without a metal precipitation mechanism. In the presence of metal ions alone, bacterial growth was inhibited at a range of concentrations depending on the metal. Microbial activity in a urea-amended medium caused carbonate ion generation and pH elevation, providing conditions suitable for calcium carbonate bioprecipitation, and consequent removal of metal ions. Elevation of pH and calcium precipitation are shown to be strongly linked to removal of zinc and cadmium, but only partially linked to removal of lead and copper. The dependence of these effects on interactions between the respective metal and precipitated calcium carbonate are discussed. Finally, it is shown that the bacterium operates at higher metal concentrations in the presence of the urea-amended medium, suggesting that the metal removal mechanism offers a defence against metal toxicity. PMID:27136729

  8. Toxicity of heavy metals to thermophilic anaerobic digestion

    Energy Technology Data Exchange (ETDEWEB)

    Ahring, B.K.; Westermann, P.

    1983-01-01

    The effects of heavy metals on the thermophilic digestion of sewage sludge was studied in three semicontinuous digesters step-fed with cadmium, copper and nickel, respectively. The daily gas production, gas composition, the quantitative accumulation of volatile fatty acids, and the distribution of the heavy metals were measured. The fermentations were carried out at 58 degrees C with a retention time of 10 days and an addition of 1.7 g volatile solids/l of reactor volume per day. Nickel was found to be 2-3 times more water soluble than cadmium and copper when the digesters were fed raw sludge containing heavy metals. The three digesters all showed tendencies to acclimate to the heavy metals up to a certain level. 200 mg nickel/l was completely inhibitory while the same response was observed for cadmium and copper at 300 mg/l. (Refs. 20).

  9. Nasal toxicity, carcinogenicity, and olfactory uptake of metals.

    Science.gov (United States)

    Sunderman, F W

    2001-01-01

    Occupational exposures to inhalation of certain metal dusts or aerosols can cause loss of olfactory acuity, atrophy of the nasal mucosa, mucosal ulcers, perforated nasal septum, or sinonasal cancer. Anosmia and hyposmia have been observed in workers exposed to Ni- or Cd-containing dusts in alkaline battery factories, nickel refineries, and cadmium industries. Ulcers of the nasal mucosa and perforated nasal septum have been reported in workers exposed to Cr(VI) in chromate production and chrome plating, or to As(III) in arsenic smelters. Atrophy of the olfactory epithelium has been observed in rodents following inhalation of NiSO4 or alphaNi3S2. Cancers of the nose and nasal sinuses have been reported in workers exposed to Ni compounds in nickel refining, cutlery factories, and alkaline battery manufacture, or to Cr(VI) in chromate production and chrome plating. In animals, several metals (eg, Al, Cd, Co, Hg, Mn, Ni, Zn) have been shown to pass via olfactory receptor neurons from the nasal lumen through the cribriform plate to the olfactory bulb. Some metals (eg, Mn, Ni, Zn) can cross synapses in the olfactory bulb and migrate via secondary olfactory neurons to distant nuclei of the brain. After nasal instillation of a metal-containing solution, transport of the metal via olfactory axons can occur rapidly, within hours or a few days (eg, Mn), or slowly over days or weeks (eg, Ni). The olfactory bulb tends to accumulate certain metals (eg, Al, Bi, Cu, Mn, Zn) with greater avidity than other regions of the brain. The molecular mechanisms responsible for metal translocation in olfactory neurons and deposition in the olfactory bulb are unclear, but complexation by metal-binding molecules such as carnosine (beta-alanyl-L-histidine) may be involved. PMID:11314863

  10. The Severity of Autism Is Associated with Toxic Metal Body Burden and Red Blood Cell Glutathione Levels

    International Nuclear Information System (INIS)

    This study investigated the relationship of children's autism symptoms with their toxic metal body burden and red blood cell (RBC) glutathione levels. In children ages 38 years, the severity of autism was assessed using four tools: ADOS, PDD-BI, ATEC, and SAS. Toxic metal body burden was assessed by measuring urinary excretion of toxic metals, both before and after oral dimercaptosuccinic acid (DMSA). Multiple positive correlations were found between the severity of autism and the urinary excretion of toxic metals. Variations in the severity of autism measurements could be explained, in part, by regression analyses of urinary excretion of toxic metals before and after DMSA and the level of RBC glutathione (adjusted R2 of 0.220.45, P<.005 in all cases). This study demonstrates a significant positive association between the severity of autism and the relative body burden of toxic metals.

  11. Monitoring of heavy/toxic metals and halides in surface/ground water (abstract)

    International Nuclear Information System (INIS)

    Water is essential for maintaining physical and social life. Human and animal consumption is perhaps the most evident essential use of water. Water quality and quantity have become critical issues, affecting all life. The importance of water in our lives, combined with the threats, make water resources use a global problem. Among the different pollutants toxic metals, metalloids and halides have special significance. Industrial effluents and municipal wastewater are normally drained into water streams, rivers and other reservoirs thus polluting these significantly. Quality of our water resources especially is an issue, which continues to arouse the attention of concerned scientists, legislators and the general public. Among various pollutant chemicals, the heavy metals and metalloids are present at trace levels in various compartments of the environment. Some metals become toxic even at trace levels because of the important features that distinguishes metals from other pollutants is that they are not biodegradable. The halides like Cl, Br, and I from different sources can enter easily into water systems and then they make their way directly into the human body. The intake of toxic as wells as essential elements through water and other food items like vegetables, milk wheat flour etc. is significant. The abundance or deficiency of these meals as well as halides results in abnormal metabolic functions. Due to excessive demand for trace analysis in water and other materials a variety of techniques and instrumentation has been developed. Determination of heavy metals ions is of the highest interest in environmental analysis. Among the food materials water is most important because of their large consumption by man. Also toxic metals in water may be in dissolved ionic form, which directly go into human metabolism and start their toxic action. Presence of even small amounts of toxic metals in drinking water can produce serious health hazards. (author)

  12. Toxicity of metals to a freshwater tubificid worm Tubifex tubifex (Muller)

    Energy Technology Data Exchange (ETDEWEB)

    Khangarot, B.S. (Industrial Toxicology Research Centre, Lucknow (India))

    1991-06-01

    Salts of various metals are being released in ever increasing amounts into the aquatic environment from mining operations, metal processing facilities, chemical industries and other similar sources. Although there has been considerable study of the acute and chronic toxicities of metals to freshwater fishes, crustaceans and snails, little information is available on the effects of metals to tubificid worms which are widely distributed in the aquatic environment. Tubificid worms are useful indicators of varying degrees of aquatic pollution. It is suggested that tubificid worms are an important element in the aquatic environment and therefore their use as a bioassay organism is logical one. The present study was undertaken to determine the acute toxicities of various metals to a fresh-water tubificid worm, Tubifex tubifex (Muller), which form an important link in aquatic food chain(s).

  13. Solidification/stabilization of toxic metals in calcium aluminate cement matrices

    International Nuclear Information System (INIS)

    Highlights: • Reliable encapsulation and effective sorption of Pb, Zn and Cu on CAC was proved. • Cu and Pb were fully retained in the CAC mortar, while Zn was retained in 99.99%. •A maximum sorption capacity ca. 60 mg/g CAC was attained for Cu. • Three different PSD patterns were established as a function of XRD phase assemblage. • Some metal-loaded mortars achieved suitable mechanical strengths for landfilling. -- Abstract: The ability of calcium aluminate cement (CAC) to encapsulate toxic metals (Pb, Zn and Cu) was assessed under two curing conditions. Changes in the consistency and in the setting time were found upon the addition of the nitrates of the target metals. Both Pb and Cu caused a delay in CAC hydration, while Zn accelerated the stiffening of the mortar. Compressive strengths of the metal-doped mortars, when initially cured at 60 °C/100% RH, were comparable with that of the free-metal mortar. Three different pore size distribution patterns were identified and related to the compounds identified by XRD and SEM. Sorbent capacities of CAC for the toxic metals were excellent: a total uptake was achieved for up to 3 wt.% loading of the three metals. In this way, CAC mortars were perfectly able to encapsulate the toxic metals, allowing the use of CAC for waste management as proved by the leaching tests

  14. Toxicity and Bioaccumulation of Heavy Metals in Spinach (Spinacia oleracea Grown in a Controlled Environment

    Directory of Open Access Journals (Sweden)

    Naz Alia

    2015-06-01

    Full Text Available The impact of heavy metal toxicity on the shoot and root lengths, total protein, fiber characteristics, moisture content and nutrient composition of spinach (Spinacia oleracea was evaluated. Plants were grown in pots containing soil and treated with different concentrations (mg/kg of lead (Pb; 300, 400 and 500, cadmium (Cd; 0.5, 1 and 1.5 and zinc (Zn; 250, 500, and 700 as well as mixtures of Cd and Pb (0.5/300, 1/400, 1.5/500, Cd and Zn (0.5/250, 1/500, 1.5/700, and Pb and Zn (300/250, 400/500, 500/700. Soil contaminated by long-term irrigation with wastewater containing heavy metals was simulated. An increase in concentrations of heavy metals both individually and as mixtures significantly (p < 0.05 reduced the growth parameters and nutrient contents of S. oleracea. The uptake patterns of heavy metals in mixtures showed antagonistic impacts on each other. The toxicities of the mixtures Cd and Pb, Cd and Zn as well as Pb and Zn were higher than those observed in separate heavy metal applications but less than their additive sums. The toxicity caused by individual heavy metals was the highest for Cd followed by Pb and Zn. The highest toxicity was observed in plants grown in soil contaminated by Cd and Pb.

  15. Toxicity and Bioaccumulation of Heavy Metals in Spinach (Spinacia oleracea) Grown in a Controlled Environment

    Science.gov (United States)

    Alia, Naz; Sardar, Khan; Said, Muhammad; Salma, Khalid; Sadia, Alam; Sadaf, Siddique; Toqeer, Ahmed; Miklas, Scholz

    2015-01-01

    The impact of heavy metal toxicity on the shoot and root lengths, total protein, fiber characteristics, moisture content and nutrient composition of spinach (Spinacia oleracea) was evaluated. Plants were grown in pots containing soil and treated with different concentrations (mg/kg) of lead (Pb; 300, 400 and 500), cadmium (Cd; 0.5, 1 and 1.5) and zinc (Zn; 250, 500, and 700) as well as mixtures of Cd and Pb (0.5/300, 1/400, 1.5/500), Cd and Zn (0.5/250, 1/500, 1.5/700), and Pb and Zn (300/250, 400/500, 500/700). Soil contaminated by long-term irrigation with wastewater containing heavy metals was simulated. An increase in concentrations of heavy metals both individually and as mixtures significantly (p < 0.05) reduced the growth parameters and nutrient contents of S. oleracea. The uptake patterns of heavy metals in mixtures showed antagonistic impacts on each other. The toxicities of the mixtures Cd and Pb, Cd and Zn as well as Pb and Zn were higher than those observed in separate heavy metal applications but less than their additive sums. The toxicity caused by individual heavy metals was the highest for Cd followed by Pb and Zn. The highest toxicity was observed in plants grown in soil contaminated by Cd and Pb. PMID:26133131

  16. Immobilized materials for removal of toxic metal ions from surface/groundwaters and aqueous waste streams.

    Science.gov (United States)

    Zawierucha, Iwona; Kozlowski, Cezary; Malina, Grzegorz

    2016-04-20

    Heavy metals from industrial processes are of special concern because they produce chronic poisoning in the aquatic environment. More strict environmental regulations on the discharge of toxic metals require the development of various technologies for their removal from polluted streams (i.e. industrial wastewater, mine waters, landfill leachate, and groundwater). The separation of toxic metal ions using immobilized materials (novel sorbents and membranes with doped ligands), due to their high selectivity and removal efficiency, increased stability, and low energy requirements, is promising for improving the environmental quality. This critical review is aimed at studying immobilized materials as potential remediation agents for the elimination of numerous toxic metal (e.g. Pb, Cd, Hg, and As) ions from polluted streams. This study covers the general characteristics of immobilized materials and separation processes, understanding of the metal ion removal mechanisms, a review of the application of immobilized materials for the removal of toxic metal ions, as well as the impacts of various parameters on the removal efficiency. In addition, emerging trends and opportunities in the field of remediation technologies using these materials are addressed. PMID:27044908

  17. Assessment of heavy metals bioavailability and toxicity toward Vibrio fischeri in sediment of the Huelva estuary.

    Science.gov (United States)

    Rosado, Daniel; Usero, José; Morillo, José

    2016-06-01

    Relationship between toxicity and bioavailable metals in sediments from the Huelva estuary and its littoral of influence was analyzed. Toxicity was assessed with Microtox(®) bioassay using a marine luminescent bacterium: Vibrio fischeri. Bioavailable metals were considered as both, acid extractable fraction of BCR procedure and the sum of exchangeable and bound to carbonates fractions of Tessier sequential extraction. A bioavailable metals index was calculated to integrate results in a single figure. Toxicity and bioavailable metals showed a similar pattern. Higher levels were found in the estuary than in the littoral (140 TU/g). In Huelva estuary, highest levels were found in the Tinto estuary (5725 TU/g), followed by the Odiel estuary (5100 TU/g) and the Padre Santo Canal (2500 TU/g). Results in this area were well over than those in nearby estuaries. Furthermore, they are similar to or even higher than those in other polluted sediments around the world. Bioavailable metal index showed a stronger correlation with acid extractable fraction of BCR (R(2) = 0.704) than that for the sum of exchangeable and bound to carbonates fractions of Tessier (R(2) = 0.661). These results suggest that bioavailable metals are an important source of sediment toxicity in the Huelva estuary and its littoral of influence, an area with one of the highest mortality risks of Spain. PMID:27002282

  18. In Vitro Pulmonary Toxicity of Metal Oxide Nanoparticles

    OpenAIRE

    Cupi, Denisa; Dreher, Kevin

    2013-01-01

    Nanomaterials (NMs) encompass a diversity of materials with unique physicochemical characteristics which raise concerns about their potential risk to human health. Rapid predictive testing methods are needed to characterize NMs health effects as well as to screen and prioritize NMs for comprehensive toxicological assessments. BEAS2B human bronchial epithelial cells were employed to assess the in vitro pulmonary toxicity of 4 TiO2 and 4 CeO2 particles varying is size (6 - 1288nm) and crystalli...

  19. Influence of organism age on metal toxicity to Daphnia magna.

    Science.gov (United States)

    Hoang, Tham C; Klaine, Stephen J

    2007-06-01

    Aquatic organisms living in surface water experience contaminant exposure at different life stages. While some investigators have examined the influence of organism age on the toxicity of pollutants, the general assumption in toxicology has been that young organisms were more sensitive than older organisms. In fact, some standardized toxicity tests call for the use of organisms less than 24 h old. This research characterized the age sensitivity of the water flea Daphnia magna to copper, zinc, selenium, and arsenic. During 21-d toxicity tests, organisms were exposed to a single 12-h pulse of either 70 microg/L Cu, 750 microg/L Zn, 1000 microg/L Se, or 5000 microg/L As at different ages ranging from 3 h to 10 d old. Mortality and reproduction were compiled over 21 d. During the juvenile stage, mortality increased and cumulative reproduction decreased with age, respectively. However, mortality decreased and cumulative reproduction increased with age when organisms became adult. Peak sensitivity occurred in 4-d-old organisms exposed to Cu and Zn, while 2- to 3-d-old organisms were most sensitive to As and Se. Growth of D. magna over 21 d was not affected by the 12-h pulse of Cu, Zn, Se, or As given at any organism age. This indicates the recovery of the organisms after exposure termination. PMID:17571686

  20. Investigation of metal toxicity to tropical biota. Recommendations for revision of Australian water quality guidelines

    International Nuclear Information System (INIS)

    The specific objectives of this study were to: review available data on the toxicity of metals to aquatic biota in tropical Australia; identify metals considered to be priority toxicants to aquatic biota in tropical Australia; and employ previously developed toxicity testing protocols for two tropical freshwater species to obtain preliminary toxicity data for two priority metals. From the literature review, it was concluded that insufficient metal toxicity data exist for Australian tropical species. Data were absent for a range of metals (eg Ag, As, Al, Cr, Hg, Ni, Sb and Se) listed in the current Australian water quality guidelines. Aluminium, Cd, Co, Cu, Ni, Mn, Pb, U, V and Zn were identified as priority metals of potential ecotoxicological concern in aquatic ecosystems of tropical Australia, largely as a consequence of mining activities, but also from urban impacts. Instead of testing the toxicity of the priority metals for which data do not currently exist (ie Al, Co, Ni and V), it was deemed more important to conduct further experimental work on Cu and U, in the context of elucidating the relatively high variability in the toxic response of these two metals. As a result, Cu and U were selected and toxicity tests conducted using two tropical freshwater species (green hydra (Hydra viridissima) and gudgeon fish (Mogurnda mogurnda)) from the Australian wet/dry tropics using test protocols designed to maximise the greatest sensitivity of metal response in the shortest period of time. Hydra viridissima was about eight times more sensitive to Cu than U, whereas M. mogurnda was about twenty times more sensitive. Once differences between the sublethal and lethal endpoints of the two organisms were corrected by statistical extrapolation, H. viridissima was approximately seven times more sensitive than M. mogurnda to U, but only about three times more sensitive to Cu. Both species were more sensitive to Cu than U. These results are generally consistent with those from

  1. A general mechanism for intracellular toxicity of metal-containing nanoparticles

    Science.gov (United States)

    Sabella, Stefania; Carney, Randy P.; Brunetti, Virgilio; Malvindi, Maria Ada; Al-Juffali, Noura; Vecchio, Giuseppe; Janes, Sam M.; Bakr, Osman M.; Cingolani, Roberto; Stellacci, Francesco; Pompa, Pier Paolo

    2014-05-01

    The assessment of the risks exerted by nanoparticles is a key challenge for academic, industrial, and regulatory communities worldwide. Experimental evidence points towards significant toxicity for a range of nanoparticles both in vitro and in vivo. Worldwide efforts aim at uncovering the underlying mechanisms for this toxicity. Here, we show that the intracellular ion release elicited by the acidic conditions of the lysosomal cellular compartment - where particles are abundantly internalized - is responsible for the cascading events associated with nanoparticles-induced intracellular toxicity. We call this mechanism a ``lysosome-enhanced Trojan horse effect'' since, in the case of nanoparticles, the protective cellular machinery designed to degrade foreign objects is actually responsible for their toxicity. To test our hypothesis, we compare the toxicity of similar gold particles whose main difference is in the internalization pathways. We show that particles known to pass directly through cell membranes become more toxic when modified so as to be mostly internalized by endocytosis. Furthermore, using experiments with chelating and lysosomotropic agents, we found that the toxicity mechanism for different metal containing NPs (such as metallic, metal oxide, and semiconductor NPs) is mainly associated with the release of the corresponding toxic ions. Finally, we show that particles unable to release toxic ions (such as stably coated NPs, or diamond and silica NPs) are not harmful to intracellular environments.The assessment of the risks exerted by nanoparticles is a key challenge for academic, industrial, and regulatory communities worldwide. Experimental evidence points towards significant toxicity for a range of nanoparticles both in vitro and in vivo. Worldwide efforts aim at uncovering the underlying mechanisms for this toxicity. Here, we show that the intracellular ion release elicited by the acidic conditions of the lysosomal cellular compartment - where

  2. Bioremediation of Heavy Metals and Organic Toxicants by Composting

    Directory of Open Access Journals (Sweden)

    Allen V. Barker

    2002-01-01

    Full Text Available Hazardous organic and metallic residues or by-products can enter into plants, soils, and sediments from processes associated with domestic, municipal, agricultural, industrial, and military activities. Handling, ingestion, application to land or other distributions of the contaminated materials into the environment might render harm to humans, livestock, wildlife, crops, or native plants. Considerable remediation of the hazardous wastes or contaminated plants, soils, and sediments can be accomplished by composting. High microbial diversity and activity during composting, due to the abundance of substrates in feedstocks, promotes degradation of xenobiotic organic compounds, such as pesticides, polycyclic aromatic hydrocarbons (PAHs, and polychlorinated biphenyls (PCBs. For composting of contaminated soils, noncontaminated organic matter should be cocomposted with the soils. Metallic pollutants are not degraded during composting but may be converted into organic combinations that have less bioavailability than mineral combinations of the metals. Degradation of organic contaminants in soils is facilitated by addition of composted or raw organic matter, thereby increasing the substrate levels for cometabolism of the contaminants. Similar to the composting of soils in vessels or piles, the on-site addition of organic matter to soils (sheet composting accelerates degradation of organic pollutants and binds metallic pollutants. Recalcitrant materials, such as organochlorines, may not undergo degradation in composts or in soils, and the effects of forming organic complexes with metallic pollutants may be nonpermanent or short lived. The general conclusion is, however, that composting degrades or binds pollutants to innocuous levels or into innocuous compounds in the finished product.

  3. Separation and Extraction of Some Heavy and Toxic Metal Ions from Their Wastes by Ionic Membranes

    International Nuclear Information System (INIS)

    Preparation and characterisation of a series of ion-exchange membranes for the purpose of separation and extraction of some heavy and toxic metal ions from their wastes have been studied. Such ion exchange membranes prepared by γ-radiation grafting of acrylonitrile (AN) and vinyl acetate (VAc) in a binary monomers mixture onto low density polyethylene (LDPE) using direct technique of grafting. The reaction conditions at which grafting process proceeds successfully have been determined. Many modification treatments have been attempted for the prepared membranes to improve their ion-exchange properties. The possibility of their practical use in waste water treatment from some heavy and toxic metal ions such as Pb2+ , Cd2+ ,Cu2+ ,Fe3+ ,Sr2+ and Li+ have been investigated. These grafted membranes showed great promise for its use in the field of extraction and removal of some heavy and toxic metals from their wastes

  4. Electrospray Ionization Mass Spectrometry: From Cluster Ions to Toxic metal Ions in Biology

    Energy Technology Data Exchange (ETDEWEB)

    Nicholas B. Lentz

    2007-12-01

    This dissertation focused on using electrospray ionization mass spectrometry to study cluster ions and toxic metal ions in biology. In Chapter 2, it was shown that primary, secondary and quarternary amines exhibit different clustering characteristics under identical instrument conditions. Carbon chain length also played a role in cluster ion formation. In Chapters 3 and 4, the effects of solvent types/ratios and various instrumental parameters on cluster ion formation were examined. It was found that instrument interface design also plays a critical role in the cluster ion distribution seen in the mass spectrum. In Chapter 5, ESI-MS was used to investigate toxic metal binding to the [Gln{sup 11}]-amyloid {beta}-protein fragment (1-16). Pb and Cd bound stronger than Zn, even in the presence of excess Zn. Hg bound weaker than Zn. There are endless options for future work on cluster ions. Any molecule that is poorly ionized in positive ion mode can potentially show an increase in ionization efficiency if an appropriate anion is used to produce a net negative charge. It is possible that drug protein or drug/DNA complexes can also be stabilized by adding counter-ions. This would preserve the solution characteristics of the complex in the gas phase. Once in the gas phase, CID could determine the drug binding location on the biomolecule. There are many research projects regarding toxic metals in biology that have yet to be investigated or even discovered. This is an area of research with an almost endless future because of the changing dynamics of biological systems. What is deemed safe today may show toxic effects in the future. Evolutionary changes in protein structures may render them more susceptible to toxic metal binding. As the understanding of toxicity evolves, so does the demand for new toxic metal research. New instrumentation designs and software make it possible to perform research that could not be done in the past. What was undetectable yesterday will become

  5. Assessment of combined toxicity of heavy metals from industrial wastewaters on Photobacterium phosphoreum T3S

    Science.gov (United States)

    Zeb, BibiSaima; Ping, Zheng; Mahmood, Qaisar; Lin, Qiu; Pervez, Arshid; Irshad, Muhammad; Bilal, Muhammad; Bhatti, Zulfiqar Ahmad; Shaheen, Shahida

    2016-02-01

    This research work is focusing on the toxicities of heavy metals of industrial origin to anaerobic digestion of the industrial wastewater. Photobacterium phosphoreum T3S was used as an indicator organism. The acute toxicities of heavy metals on P. phosphoreum T3S were assessed during 15-min half inhibitory concentration (IC50) as indicator at pH 5.5-6. Toxicity assays involved the assessment of multicomponent mixtures using TU and MTI approaches. The results of individual toxicity indicated that the toxicity of Cd, Cu and Pb on P. phosphoreum increased with increasing concentrations and there was a linear correlation. The 15-min IC50 values of Cd, Cu and Pb were 0.537, 1.905 and 1.231 mg/L, respectively, and their toxic order was Cd > Pb > Cu. The combined effects of Cd, Cu and Pb were assayed by equivalent concentration mixing method. The results showed that the combined effects of Cd + Cu, Cd + Pb, Cu + Pb, Cd + Cu + Pb were antagonistic, antagonistic and partly additive. The combined effect of three heavy metals was partly additive.

  6. Sub-chronic toxicity and heavy metal toxicity study on Kappaphycus alvarezii in albino rats

    Institute of Scientific and Technical Information of China (English)

    AbiramiRG; KowsalyaS

    2012-01-01

    Objective: This study aimed to evaluate the toxicity of Kappaphycus alvarezii methanolic extracts in albino rats. Methods: Sub-chronic toxicity was tested with a single dose of intraperitonal administration of the extract as per the OECD guidelines in the experimental group rats and the control group rats was fed with standard diet and water ad libitum. Mortality, behaviour changes, clinical signs and symptoms, food intake, body weight and any abnormalities of the visceral organs were observed. Results: The results revealed that the algal extract resulted in neither mortality nor any abnormalities. The Most of the serum biochemical parameters and hematological values were similar in control and experimental groups, histopathological examination of the vital organs like liver, kidney, spleen, brain and heart revealed no obvious abnormality in the control group and Kappaphycus alvarezii treated group. Conclusion: It may be concluded that Kappaphycus alvarezii rich in nutrient and nutraceutial potentials and also safety food for human consumption.

  7. Assessment of metal releases and leachate toxicity of oil sands coke

    International Nuclear Information System (INIS)

    Large volumes of coke are produced as a by-product of thermal upgrading of oil sands bitumen in Alberta. This paper examined the feasibility of integrating this stored by-product at wetland reclamation sites. Coke leachate water toxicity was evaluated in this study since coke is known to releases trace amounts of metals when it comes in contact with water. The objective was to determine the cause of toxicity by performing toxicity identification evaluations (TIEs) on the leachate. The leachability of metals from coke was examined over a 45 day period in 2-L glass jars using reconstituted water with a hardness of 300 mg/L as calcium carbonate (CaCO3) at pH levels 5.5 and 9.5. Coke porewater samples and overlying water samples collected periodically were analyzed for trace metals using inductively coupled plasma mass spectroscopy (ICP-MS). The toxicity of coke leachate was evaluated at the end of the 45 day period using a Ceriodaphnia dubia standard three-brood chronic test with survival and reproduction as endpoints. Coke leachate water from both pH treatments had a negative effect on survival and reproduction of C. dubia. The coke leachate had high concentrations of vanadium, according to metal analysis of leachate water from both pH treatments. In order to identify the cause of toxicity, the coke leachate water will be subjected to several TIE processes

  8. Recovery of toxic metal ions from washing effluent containing excess aminopolycarboxylate chelant in solution.

    Science.gov (United States)

    Hasegawa, Hiroshi; Rahman, Ismail M M; Nakano, Masayoshi; Begum, Zinnat A; Egawa, Yuji; Maki, Teruya; Furusho, Yoshiaki; Mizutani, Satoshi

    2011-10-15

    Aminopolycarboxylate chelants (APCs) are extremely useful for a variety of industrial applications, including the treatment of toxic metal-contaminated solid waste materials. Because non-toxic matrix elements compete with toxic metals for the binding sites of APCs, an excess of chelant is commonly added to ensure the adequate sequestration of toxic metal contaminants during waste treatment operations. The major environmental impacts of APCs are related to their ability to solubilize toxic heavy metals. If APCs are not sufficiently eliminated from the effluent, the aqueous transport of metals can occur through the introduction of APCs into the natural environment, increasing the magnitude of associated toxicity. Although several techniques that focus primarily on the degradation of APCs at the pre-release step have been proposed, methods that recycle not only the processed water, but also provide the option to recover and reuse the metals, might be economically feasible, considering the high costs involved due to the chelants used in metal ion sequestration. In this paper, we propose a separation process for the recovery of metals from effluents that contain an excess of APCs. Additionally, the option of recycling the processed water using a solid phase extraction (SPE) system with an ion-selective immobilized macrocyclic material, commonly known as a molecular recognition technology (MRT) gel, is presented. Simulated effluents containing As(V), Cd(II), Cr(III), Pb(II) or Se(IV) in the presence of APCs at molar ratios of 1:50 in H2O were studied with a flow rate of 0.2 mL min(-1). The 'captured' ions in the SPE system were quantitatively eluted with HNO3. The effects of solution pH, metal-chelant stability constants and matrix elements were assessed. Better separation performance for the metals was achieved with the MRT-SPE compared to other SPE materials. Our proposed technique offers the advantage of a non-destructive separation of both metal ions and chelants

  9. Caddisflies as biomonitors identifying thresholds of toxic metal bioavailability that affect the stream benthos

    International Nuclear Information System (INIS)

    It has been proposed that bioaccumulated concentrations of toxic metals in tolerant biomonitors be used as indicators of metal bioavailability that could be calibrated against the ecological response to metals of sensitive biotic assemblages. Our hypothesis was that metal concentrations in caddisfly larvae Hydropsyche siltalai and Plectrocnemia conspersa, as tolerant biomonitors, indicate metal bioavailability in contaminated streams, and can be calibrated against metal-specific ecological responses of mayflies. Bioaccumulated concentrations of Cu, As, Zn and Pb in H. siltalai from SW English streams were related to the mayfly assemblage. Mayflies were always sparse where bioavailabilities were high and were abundant and diverse where bioavailabilities of all metals were low, a pattern particularly evident when the combined abundance of heptageniid and ephemerellid mayflies was the response variable. The results offer promise that bioaccumulated concentrations of metals in tolerant biomonitors can be used to diagnose ecological impacts on stream benthos from metal stressors. - Highlights: ► Metal concentrations in caddisfly larvae can be calibrated against mayfly ecological responses. ► Cu, As, Zn and Pb concentrations in Hydropsyche siltalai were related to stream mayfly assemblages. ► Mayflies were sparse in high metal bioavailabilities, and abundant in low bioavailabilities. ► Joint heptageniid and ephemerellid mayfly abundance was the most sensitive response variable. ► Copper, arsenic and, in one catchment, lead were the primary stressors limiting mayfly abundance. - Accumulated metal concentrations in tolerant biomonitors can be used to detect and diagnose ecological impacts on freshwater stream benthos from metal stressors.

  10. Suitability of Daphnia similis as an alternative organism in ecotoxicological tests: implications for metal toxicity.

    Science.gov (United States)

    Rodgher, Suzelei; Espíndola, Evaldo Luiz Gaeta; Lombardi, Ana Teresa

    2010-08-01

    The acute toxicity of metals to Daphnia similis was determined and compared to other daphnid species to evaluate the suitability of this organism in ecotoxicology bioassays. To verify the performance D. similis in toxicity tests, we also investigated the effect of Pseudokirchneriella subcapitata at 1 x 10(5) and 1 x 10(6) cells ml(-1) on Cd and Cr acute toxicity to the cladoceran. Daphnid neonates were exposed to a range of chromium and cadmium concentrations in the absence and presence of the algal cells. Metal speciation calculations using MINEQL(+) showed that total dissolved metal concentrations in zooplankton culture corresponded to 96.2% free Cd and 100% free Cr concentrations. Initial total dissolved metal concentrations were used for 48 h-LC(50) determination. LC(50) for D. similis was 5.15 x 10(-7) mol l(-1) dissolved Cd without algal cells, whereas with 1 x 10(5) cells ml(-1), it was significantly higher (7.15 x 10(-7) mol l(-1) dissolved Cd). For Cr, the 48 h-LC(50) value of 9.17 x 10(-7) mol l(-1) obtained for the cladoceran in tests with 1 x 10(6) cells ml(-1) of P. subcapitata was also significantly higher than that obtained in tests without algal cells (5.28 x 10(-7) mol l(-1) dissolved Cr). The presence of algal cells reduced the toxicity of metals to D. similis, as observed in other studies that investigated the effects of food on metal toxicity to standard cladocerans. Comparing our results to those of literature, we observed that D. similis is as sensitive to metals as other standardized Daphnia species and may serve as a potential test species in ecotoxicological evaluations. PMID:20306222

  11. Metal Oxide Nanoparticles: The Importance of Size, Shape, Chemical Composition, and Valence State in Determining Toxicity

    Science.gov (United States)

    Dunnick, Katherine

    Nanoparticles, which are defined as a structure with at least one dimension between 1 and 100 nm, have the potential to be used in a variety of consumer products due to their improved functionality compared to similar particles of larger size. Their small size is associated with increased strength, improved catalytic properties, and increased reactivity; however, their size is also associated with increased toxicity in vitro and in vivo. Numerous toxicological studies have been conducted to determine the properties of nanomaterials that increase their toxicity in order to manufacture new nanomaterials with decreased toxicity. Data indicates that size, shape, chemical composition, and valence state of nanomaterials can dramatically alter their toxicity profile. Therefore, the purpose of this dissertation was to determine how altering the shape, size, and chemical composition of various metal oxide nanoparticles would affect their toxicity. Metal oxides are used in variety of consumer products, from spray-sun screens, to food coloring agents; thus, understanding the toxicity of metal oxides and determining which aspects affect their toxicity may provide safe alternatives nanomaterials for continued use in manufacturing. Tungstate nanoparticles toxicity was assessed in an in vitro model using RAW 264.7 cells. The size, shape, and chemical composition of these nanomaterials were altered and the effect on reactive oxygen species and general cytotoxicity was determined using a variety of techniques. Results demonstrate that shape was important in reactive oxygen species production as wires were able to induce significant reactive oxygen species compared to spheres. Shape, size, and chemical composition did not have much effect on the overall toxicity of these nanoparticles in RAW 264.7 cells over a 72 hour time course, implicating that the base material of the nanoparticles was not toxic in these cells. To further assess how chemical composition can affect toxicity

  12. Metal toxicity in a sediment-dwelling polychaete: Threshold body concentrations or overwhelming accumulation rates?

    Energy Technology Data Exchange (ETDEWEB)

    Carmen Casado-Martinez, M., E-mail: c.casado-martinez@nhm.ac.u [Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Smith, Brian D. [Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Luoma, Samuel N. [John Muir Institute of the Environment, University of California at Davis, Davis, CA 95616 (United States); Rainbow, Philip S. [Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom)

    2010-10-15

    We followed the net accumulation of As, Cu and Zn in the deposit-feeding polychaete Arenicola marina exposed in the laboratory to natural metal-contaminated sediments, one exposure leading to mass mortality between day 10 and 20, and the other not causing lethality over a period of 60 days of exposure. The worms showed lower total accumulated metal concentrations just before mortality occurred (<20 days) at the lethal exposure, than after 30 days of exposure to sediments not causing mortality. Moreover rates of accumulation of As, Cu and Zn were significantly higher in the lethal exposure than in the sublethal exposure. Our results show that it is not possible to link mortality to a critical total body concentration, and we add to a growing body of literature indicating that metal toxicity occurs when organisms cannot cope with overwhelming influx and subsequent accumulation rates. - Laboratory exposures with the deposit-feeding polychaete Arenicola marina suggest that toxicity is not caused by the accumulated concentration of toxic metals in the body of the animal, but by the rate at which the toxic metal is accumulated.

  13. Preliminary assessment of metal toxicity in the middle Tisza river (Hungary) flood plain

    Energy Technology Data Exchange (ETDEWEB)

    Black, M.C.; Williams, P.L. [Dept. of Environmental Health Science, Univ. of Georgia, Athens, GA (United States)

    2001-07-01

    Cyanide and heavy metals were accidentally released from a mine waste lagoon in Romania into tributaries ultimately draining into the Tisza River. Within two months of the cyanide accident two subsequent heavy metal waste spills further contaminated the Tisza River, followed by severe spring flooding, which potentially spread the contamination to soils adjacent to the river. Flood plain soils and shoreline sediments were sampled from two locations on the middle Tisza River and a reference site to conduct a preliminary assessment of metal content and toxicity. Ten-day sediment toxicity tests were conducted with the amphipod, Hyalella azteca and 24 h soil toxicity tests were conducted with the nematode (Caenorhabditis elegans). High concentrations of cadmium, copper, zinc, lead and arsenic were detected in soil and sediment samples. However, no mortality was observed in Hyalella exposed to Tisza River sediments and only up to 27% mortality of C. elegans was observed in flood plain soils. Low mortalities are attributed to reduced metal bioavailability caused by high soil cation exchange capacities and possible interactions with sediment organic matter or sulfides. Future studies should focus on factors that alter metal bioavailability and their relationship to potential toxicity of organisms exposed to Tisza River sediments and flood plain soils. (orig.)

  14. Assessing time-integrated dissolved concentrations and predicting toxicity of metals during diel cycling in streams

    Science.gov (United States)

    Balistrieri, Laurie S.; Nimick, David A.; Mebane, Christopher A.

    2012-01-01

    Evaluating water quality and the health of aquatic organisms is challenging in systems with systematic diel (24 h) or less predictable runoff-induced changes in water composition. To advance our understanding of how to evaluate environmental health in these dynamic systems, field studies of diel cycling were conducted in two streams (Silver Bow Creek and High Ore Creek) affected by historical mining activities in southwestern Montana. A combination of sampling and modeling tools was used to assess the toxicity of metals in these systems. Diffusive Gradients in Thin Films (DGT) samplers were deployed at multiple time intervals during diel sampling to confirm that DGT integrates time-varying concentrations of dissolved metals. Site specific water compositions, including time-integrated dissolved metal concentrations determined from DGT, a competitive, multiple-toxicant biotic ligand model, and the Windemere Humic Aqueous Model Version 6.0 (WHAM VI) were used to determine the equilibrium speciation of dissolved metals and biotic ligands. The model results were combined with previously collected toxicity data on cutthroat trout to derive a relationship that predicts the relative survivability of these fish at a given site. This integrative approach may prove useful for assessing water quality and toxicity of metals to aquatic organisms in dynamic systems and evaluating whether potential changes in environmental health of aquatic systems are due to anthropogenic activities or natural variability.

  15. Metal toxicity in a sediment-dwelling polychaete: Threshold body concentrations or overwhelming accumulation rates?

    International Nuclear Information System (INIS)

    We followed the net accumulation of As, Cu and Zn in the deposit-feeding polychaete Arenicola marina exposed in the laboratory to natural metal-contaminated sediments, one exposure leading to mass mortality between day 10 and 20, and the other not causing lethality over a period of 60 days of exposure. The worms showed lower total accumulated metal concentrations just before mortality occurred (<20 days) at the lethal exposure, than after 30 days of exposure to sediments not causing mortality. Moreover rates of accumulation of As, Cu and Zn were significantly higher in the lethal exposure than in the sublethal exposure. Our results show that it is not possible to link mortality to a critical total body concentration, and we add to a growing body of literature indicating that metal toxicity occurs when organisms cannot cope with overwhelming influx and subsequent accumulation rates. - Laboratory exposures with the deposit-feeding polychaete Arenicola marina suggest that toxicity is not caused by the accumulated concentration of toxic metals in the body of the animal, but by the rate at which the toxic metal is accumulated.

  16. Investigation of Toxic Heavy Metals in Drinking Water of Agra City, India

    Directory of Open Access Journals (Sweden)

    P. Susan Verghese

    2015-09-01

    Full Text Available Water quality of Agra city is impaired by the presence of large number of industries in the city. From the observed data it is found that drinking water of Agra city is contaminated with toxic heavy metals like chromium, copper, cadmium, lead, and nickel. Among all these heavy metals, chromium is found to be in comparatively large amounts because most of the leather industries located in Agra city adopt chrome tanning procedure as their basic step for dehairing and dehiding. Presence of high concentration of chromium and other heavy metals in drinking water pose deleterious effects on the health of human beings therefore it becomes necessary to employ certain technological methods to keep the concentration of such toxic heavy metals within their desirable limits.

  17. Polyurethane and alginate immobilized algal biomass for the removal of aqueous toxic metals

    International Nuclear Information System (INIS)

    We describe the development of immobilized, processed algal biomass for use as an adsorptive filter in the removal of toxic metals from waste water. To fabricate an adsorptive filter from precessed biomass several crucial criteria must be met, including: (1) high metal binding capacity, (2) long term stability (both mechanical and chemical), (3) selectivity for metals of concern (with regard to ionic competition), (4) acceptable flow capacity (to handle large volumes in short time frames), (5) stripping/regeneration (to recycle the adsorptive filter and concentrate the toxic metals to manageable volumes). This report documents experiments with processed algal biomass (Spirulina platensis and Spirulina maxima) immobilized in either alginate gel or preformed polyurethane foam. The adsorptive characteristics of these filters were assessed with regard to the criteria listed above

  18. Bioremediation of Heavy Metals and Organic Toxicants by Composting

    OpenAIRE

    Allen V. Barker; Gretchen M. Bryson

    2002-01-01

    Hazardous organic and metallic residues or by-products can enter into plants, soils, and sediments from processes associated with domestic, municipal, agricultural, industrial, and military activities. Handling, ingestion, application to land or other distributions of the contaminated materials into the environment might render harm to humans, livestock, wildlife, crops, or native plants. Considerable remediation of the hazardous wastes or contaminated plants, soils, and sediments can be acco...

  19. Soil metal concentrations and toxicity: Associations with distances to industrial facilities and implications for human health

    Energy Technology Data Exchange (ETDEWEB)

    Aelion, C. Marjorie [Department of Environmental Health Sciences, University of South Carolina, 921 Assembly Street, Columbia, SC 29208 (United States); Department of Public Health, University of Massachusetts, 715 North Pleasant Street, Amherst, MA 01003 (United States)], E-mail: maelion@schoolph.umass.edu; Davis, Harley T. [Department of Environmental Health Sciences, University of South Carolina, 921 Assembly Street, Columbia, SC 29208 (United States); McDermott, Suzanne [Department of Family and Preventive Medicine, University of South Carolina, 3209 Colonial Drive, Columbia, SC 29203 (United States); Lawson, Andrew B. [Department of Biostatistics, Bioinformatics, and Epidemiology, Medical University of South Carolina, 135 Cannon Street, Charleston, SC 29425 (United States)

    2009-03-15

    Urban and rural areas may have different levels of environmental contamination and different potential sources of exposure. Many metals, i.e., arsenic (As), lead (Pb), and mercury (Hg), have well-documented negative neurological effects, and the developing fetus and young children are particularly at risk. Using a database of mother and child pairs, three areas were identified: a rural area with no increased prevalence of mental retardation and developmental delay (MR/DD) (Area A), and a rural area (Area B) and an urban area (Area C) with significantly higher prevalence of MR/DD in children as compared to the state-wide average. Areas were mapped and surface soil samples were collected from nodes of a uniform grid. Samples were analyzed for As, barium (Ba), beryllium (Be), chromium (Cr), copper (Cu), Pb, manganese (Mn), nickel (Ni), and Hg concentrations and for soil toxicity, and correlated to identify potential common sources. ArcGIS was used to determine distances between sample locations and industrial facilities, which were correlated with both metal concentrations and soil toxicity. Results indicated that all metal concentrations (except Be and Hg) in Area C were significantly greater than those in Areas A and B (p {<=} 0.0001) and that Area C had fewer correlations between metals suggesting more varied sources of metals than in rural areas. Area C also had a large number of facilities whose distances were significantly correlated with metals, particularly Cr (maximum r = 0.33; p = 0.0002), and with soil toxicity (maximum r = 0.25; p = 0.007) over a large spatial scale. Arsenic was not associated with distance to any facility and may have a different anthropogenic, or natural source. In contrast to Area C, both rural areas had lower concentrations of metals, lower soil toxicity, and a small number of facilities with significant associations between distance and soil metals.

  20. Potentially Toxic Metal and Metalloid Fractionation Contamination in Sediments of Daya Bay, South China Sea

    OpenAIRE

    Cao, L. L.; Yang, J; P. Wang; Wang, L.; Tian, H. T.; Zou, M. K.; Xie, J.

    2015-01-01

    The metal profiles in sediments of the Daya Bay (DYB) in China were established using sequential extraction protocols proposed by the European Community Bureau of Reference (BCR). The surface sediment samples from 23 representative stations were collected in 2011 and were analysed to evaluate the mobility and bioavailability of a suite of potentially toxic metals (Cr, Cu, Ni, Zn, Pb and Cd) and metalloid (As). The obtained ranking order of migration and transformation, and the degree of pollu...

  1. Depth Profiling (ICP-MS Study of Toxic Metal Buildup in Concrete Matrices: Potential Environmental Impact

    Directory of Open Access Journals (Sweden)

    Ghada Bassioni

    2010-10-01

    Full Text Available This paper explores the potential of concrete material to accumulate toxic trace elements using ablative laser technology (ICP-MS. Concrete existing in offshore structures submerged in seawater acts as a sink for hazardous metals, which could be gradually released into the ocean creating pollution and anoxic conditions for marine life. Ablative laser technology is a valuable tool for depth profiling concrete to evaluate the distribution of toxic metals and locate internal areas where such metals accumulate. Upon rapid degradation of concrete these “hotspots” could be suddenly released, thus posing a distinct threat to aquatic life. Our work simulated offshore drilling conditions by immersing concrete blocks in seawater and investigating accumulated toxic trace metals (As, Be, Cd, Hg, Os, Pb in cored samples by laser ablation. The experimental results showed distinct inhomogeneity in metal distribution. The data suggest that conditions within the concrete structure are favorable for random metal accumulation at certain points. The exact mechanism for this behavior is not clear at this stage and has considerable scope for extended research including modeling and remedial studies.

  2. Effect of toxic metals on indigenous soil {beta}-subgroup proteobacterium ammonia oxidizer community structure and protection against toxicity by inoculated metal-resistant bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Stephen, J.R.; Chang, Y.J.; MacNaughton, S.J.; Leung, K.T.; Flemming, C.A. [Univ. of Tennessee, Knoxville, TN (United States). Center for Environmental Biotechnology; Kowalchuk, G.A. [Netherlands Inst. of Ecology, Heteren (Netherlands); White, D.C. [Univ. of Tennessee, Knoxville, TN (United States). Center for Environmental Biotechnology]|[Oak Ridge National Lab., TN (United States). Biological Sciences Div.

    1999-01-01

    Contamination of soils with toxic metals is a major problem on military, industrial, and mining sites worldwide. Of particular interest to the field of bioremediation is the selection of biological markers for the end point of remediation. In this microcosm study, the authors focus on the effect of addition of a mixture of toxic metals (cadmium, cobalt, cesium, and strontium as chlorides) to soil on the population structure and size of the ammonia, oxidizers that are members of the beta subgroup of the Proteobacteria. In a parallel experiment, the soils were also treated by the addition of five strains of metal-resistant heterotrophic bacteria. Effects on nitrogen cycling were measured by monitoring the NH{sub 3} and NH{sub 4}{sup +} levels in soil samples. The gene encoding the {alpha}-subunit of ammonia monooxygenase (amoA) was selected as a functional molecular marker for the {beta}-subgroup ammonia oxidizing bacteria. Community structure comparisons were performed with clone libraries of PCR-amplified fragments of amoA recovered from contaminated and control microcosms for 8 weeks. Analysis was performed by restriction digestion and sequence comparison. The abundance of ammonia oxidizers in these microcosms was also monitored by competitive PCR. All amoA gene fragments recovered grouped with sequences derived from cultured Nitrosospira. These comprised four novel sequence clusters and a single unique clone. Specific changes in the community structure of {beta}-subgroup ammonia oxidizers were associated with the addition of metals. These changes were not seen in the presence of the inoculated metal-resistant bacteria. Neither treatment significantly altered the total number of {beta}-subgroup ammonia-oxidizing cells per gram of soil compared to untreated controls. Following an initial decrease in concentration, ammonia began to accumulate in metal-treated soils toward the end of the experiment.

  3. Assessment of metal contamination, bioavailability, toxicity and bioaccumulation in extreme metallic environments (Iberian Pyrite Belt) using Corbicula fluminea.

    Science.gov (United States)

    Bonnail, E; Sarmiento, A M; DelValls, T A; Nieto, J M; Riba, I

    2016-02-15

    The Iberian Pyrite Belt (SW Iberian Peninsula) has intense mining activity. Currently, its fluvial networks receive extremely acid lixiviate residue discharges that are rich in sulphates and metals in solution (acid mine drainage, AMD) from abandoned mines. In the current study, the sediment and water quality were analysed in three different areas of the Odiel River to assess the risk associated with the metal content and its speciation and bioavailability. Furthermore, sediment contact bioassays were performed using the freshwater clam Corbicula fluminea to determine its adequacy as a biomonitoring tool in relation to theoretical risk indexes and regulatory thresholds. Reburial activity and mortality were used as the toxic responses of clams when exposed to contaminated sediment. The results showed coherence between the water and sediment chemical contamination for most of the metals. The reburial activity was correlated with the metal toxicity, but no clam mortality was registered. The bioaccumulation of the studied metals in the clam did not have a significant correlation with the bioavailable fraction of the metal content in the environment, which could be related to a potential different speciation in this singular environment. The bioaccumulation responses were negative for As, Cd and Zn in highly contaminated environments and were characterized as severe, considerable and low potential environmental risks, respectively. The results show that C. fluminea is a good biomonitor of Cu and Pb. PMID:26774961

  4. Insights into aquatic toxicities of the antibiotics oxytetracycline and ciprofloxacin in the presence of metal: Complexation versus mixture

    International Nuclear Information System (INIS)

    Co-contamination of ligand-like antibiotics (e.g., tetracyclines and quinolones) and heavy metals prevails in the environment, and thus the complexation between them is involved in environmental risks of antibiotics. To understand toxicological significance of the complex, effects of metal coordination on antibiotics' toxicity were investigated. The complexation of two antibiotics, oxytetracycline and ciprofloxacin, with three heavy metals, copper, zinc, and cadmium, was verified by spectroscopic techniques. The antibiotics bound metals via multiple coordination sites and rendered a mixture of various complexation speciations. Toxicity analysis indicated that metal coordination did modify the toxicity of the antibiotics and that antibiotic, metal, and their complex acted primarily as concentration addition. Comparison of EC50 values revealed that the complex commonly was highest toxic and predominately correlated in toxicity to the mixture. Finally, environmental scenario analysis demonstrated that ignoring complexation would improperly classify environmental risks of the antibiotics. - Highlights: ► The complex of antibiotic with metal is a mixture of various complexation modes. ► Antibiotic and metal act as various combined interactions when their complexation is ignored. ► Antibiotic, metal, and their complex act as concentration addition interaction. ► Complex commonly is the highest toxicant. ► Neglecting complexation renders improper classification of risks for antibiotics. - Antibiotic, heavy metal and their complex act primarily as concentration addition interaction and the complex commonly is highest toxic.

  5. Selecting a sensitive battery of bioassays to detect toxic effects of metals in effluents.

    Science.gov (United States)

    de Paiva Magalhães, Danielly; da Costa Marques, Mônica Regina; Fernandes Baptista, Darcilio; Forsin Buss, Daniel

    2014-09-01

    The use of bioassay batteries is necessary to evaluate toxic effects at various biological levels. The selection of bioassays without prior testing and determination of the most sensitive/suitable groups for each impact may allow the discharge of effluents that pose a threat to the environment. The present study tested and selected a battery of sensitive ecotoxicological bioassays for detecting toxic effects of metals. The sensitivities of six organisms were evaluated (algae Pseudokirchneriella subcapitata and Chlorella vulgaris, Cladocera Daphnia similis and Ceriodaphnia dubia, and fish Poecilia reticulata and Danio rerio) after exposure to 10 individual metal species deemed toxic to the aquatic environment (Ag(+), Cd(2+), Cu(+), Cu(2+), Cr(3+), Cr(6+), Pb(2+), Ni(2+), Zn(2+), and Hg(2+)) and to real (steel-mill) and laboratory simulated effluents. In the bioassays, fish were the least sensitive; D. rerio showed no sensitivity to any of the effluents tested. P. subcapitata was a good bioindicator of Cr(3+) toxicity, and D. similis was the most sensitive organism to Hg(2+); but the toxic effect of effluents with higher levels of Hg(2+) was better detected by C. dubia. The most sensitive battery of bioassays to detect low concentrations of dissolved metals in effluents was the 72-h chronic test with C. vulgaris and the 48-h acute test with C. dubia. PMID:25199585

  6. Deposition of airborne radioiodine species on surfaces of metals and plastics

    International Nuclear Information System (INIS)

    In this study the deposition velocity of gaseous radioiodine species I2, HOI and CH3I on several materials, which are commonly used in nuclear industry, was experimentally evaluated. Materials were identified which cause minimal deposition loss of airborne radioiodine sample in remote sampling systems. It was found that carbon steel and stainless steel, both extensively used in the construction of sampling lines, have high affinity for elemental iodine vapour. This causes significant loss of iodine sample due to wall deposition, particularly at high humidities which prevail under emergency release conditions. Aluminum, polyethylene and teflon cause minimal loss of iodine sample in remote sampling applications under both normal and emergency release conditions in nuclear power plants

  7. Effects of particle composition and species on toxicity of metallic nanomaterials in aquatic organisms.

    Science.gov (United States)

    Griffitt, Robert J; Luo, Jing; Gao, Jie; Bonzongo, Jean-Claude; Barber, David S

    2008-09-01

    Metallic nanoparticles are among the most widely used types of engineered nanomaterials; however, little is known about their environmental fate and effects. To assess potential environmental effects of engineered nanometals, it is important to determine which species are sensitive to adverse effects of various nanomaterials. In the present study, zebrafish, daphnids, and an algal species were used as models of various trophic levels and feeding strategies. To understand whether observed effects are caused by dissolution, particles were characterized before testing, and particle concentration and dissolution were determined during exposures. Organisms were exposed to silver, copper, aluminum, nickel, and cobalt as both nanoparticles and soluble salts as well as to titanium dioxide nanoparticles. Our results indicate that nanosilver and nanocopper cause toxicity in all organisms tested, with 48-h median lethal concentrations as low as 40 and 60 microg/L, respectively, in Daphnia pulex adults, whereas titanium dioxide did not cause toxicity in any of the tests. Susceptibility to nanometal toxicity differed among species, with filter-feeding invertebrates being markedly more susceptible to nanometal exposure compared with larger organisms (i.e., zebrafish). The role of dissolution in observed toxicity also varied, being minor for silver and copper but, apparently, accounting for most of the toxicity with nickel. Nanoparticulate forms of metals were less toxic than soluble forms based on mass added, but other dose metrics should be developed to accurately assess concentration-response relationships for nanoparticle exposures. PMID:18690762

  8. Potential resource and toxicity impacts from metals in waste electronic devices.

    Science.gov (United States)

    Woo, Seung H; Lee, Dae Sung; Lim, Seong-Rin

    2016-04-01

    As a result of the continuous release of new electronic devices, existing electronic devices are quickly made obsolete and rapidly become electronic waste (e-waste). Because e-waste contains a variety of metals, information about those metals with the potential for substantial environmental impact should be provided to manufacturers, recyclers, and disposers to proactively reduce this impact. This study assesses the resource and toxicity (i.e., cancer, noncancer, and ecotoxicity) potentials of various heavy metals commonly found in e-waste from laptop computers, liquid-crystal display (LCD) monitors, LCD TVs, plasma TVs, color cathode ray tube (CRT) TVs, and cell phones and then evaluates such potentials using life cycle impact-based methods. Resource potentials derive primarily from Cu, Sb, Ag, and Pb. Toxicity potentials derive primarily from Pb, Ni, and Hg for cancer toxicity; from Pb, Hg, Zn, and As for noncancer toxicity; and from Cu, Pb, Hg, and Zn for ecotoxicity. Therefore, managing these heavy metals should be a high priority in the design, recycling, and disposal stages of electronic devices. PMID:27017840

  9. Assessment of Toxic Metals and feed habits of the snail Pomacea specie from the Amatitlan Lake

    International Nuclear Information System (INIS)

    In the present thesis an assesment of cadmium, cooper, cromium VI, and lead was made in samples of snail pomacea specie from the Amatitlan Lake. We conclude that the comsuption of this mollusk is toxic for human health. The concentration of heavy metals like cadmium, cooper shows that are not recomended for human comsuption according to Spanish and FAO/PAHO standards

  10. Imprinted Genes and the Environment: Links to the Toxic Metals Arsenic, Cadmium and Lead

    Directory of Open Access Journals (Sweden)

    Lisa Smeester

    2014-06-01

    Full Text Available Imprinted genes defy rules of Mendelian genetics with their expression tied to the parent from whom each allele was inherited. They are known to play a role in various diseases/disorders including fetal growth disruption, lower birth weight, obesity, and cancer. There is increasing interest in understanding their influence on environmentally-induced disease. The environment can be thought of broadly as including chemicals present in air, water and soil, as well as food. According to the Agency for Toxic Substances and Disease Registry (ATSDR, some of the highest ranking environmental chemicals of concern include metals/metalloids such as arsenic, cadmium, lead and mercury. The complex relationships between toxic metal exposure, imprinted gene regulation/expression and health outcomes are understudied. Herein we examine trends in imprinted gene biology, including an assessment of the imprinted genes and their known functional roles in the cell, particularly as they relate to toxic metals exposure and disease. The data highlight that many of the imprinted genes have known associations to developmental diseases and are enriched for their role in the TP53 and AhR pathways. Assessment of the promoter regions of the imprinted genes resulted in the identification of an enrichment of binding sites for two transcription factor families, namely the zinc finger family II and PLAG transcription factors. Taken together these data contribute insight into the complex relationships between toxic metals in the environment and imprinted gene biology.

  11. Immobilization of toxic metals in solidified systems of siloxo-sial networks

    Czech Academy of Sciences Publication Activity Database

    Hanzlíček, Tomáš; Steinerová, Michaela

    2006-01-01

    Roč. 89, č. 3 (2006), s. 968-970. ISSN 0002-7820 R&D Projects: GA AV ČR IBS3046004 Institutional research plan: CEZ:AV0Z30460519 Keywords : waste toxic metals * siloxo- sial network * anorganic polymer Subject RIV: JJ - Other Materials Impact factor: 1.396, year: 2006

  12. Toxic airborne S, PAH, and trace element legacy of the superhigh-organic-sulphur Raša coal combustion: Cytotoxicity and genotoxicity assessment of soil and ash.

    Science.gov (United States)

    Medunić, Gordana; Ahel, Marijan; Mihalić, Iva Božičević; Srček, Višnja Gaurina; Kopjar, Nevenka; Fiket, Željka; Bituh, Tomislav; Mikac, Iva

    2016-10-01

    This paper presents the levels of sulphur, polycyclic aromatic hydrocarbons (PAHs), and potentially toxic trace elements in soils surrounding the Plomin coal-fired power plant (Croatia). It used domestic superhigh-organic-sulphur Raša coal from 1970 until 2000. Raša coal was characterised by exceptionally high values of S, up to 14%, making the downwind southwest (SW) area surrounding the power plant a significant hotspot. The analytical results show that the SW soil locations are severely polluted with S (up to 4%), and PAHs (up to 13,535ng/g), while moderately with Se (up to 6.8mg/kg), and Cd (up to 4.7mg/kg). The composition and distribution pattern of PAHs in the polluted soils indicate that their main source could be airborne unburnt coal particles. The atmospheric dispersion processes of SO2 and ash particles have influenced the composition and distribution patterns of sulphur and potentially toxic trace elements in studied soils, respectively. A possible adverse impact of analysed soil on the local karstic environment was evaluated by cytotoxic and genotoxic methods. The cytotoxicity effects of soil and ash water extracts on the channel catfish ovary (CCO) cell line were found to be statistically significant in the case of the most polluted soil and ash samples. However, the primary DNA-damaging potential of the most polluted soil samples on the CCO cells was found to be within acceptable boundaries. PMID:27232961

  13. Acute toxicity of metals and reference toxicants to a freshwater ostracod, Cypris subglobosa Sowerby, 1840 and correlation to EC{sub 50} values of other test models

    Energy Technology Data Exchange (ETDEWEB)

    Khangarot, B.S., E-mail: bkhangarot@hotmail.com [Ecotoxicology Division, Indian Institute of Toxicology Research (Formerly: Industrial Toxicology Research Centre), Post Box No. 80, Mahatma Gandhi Marg, Lucknow 226001 (India); Das, Sangita [Ecotoxicology Division, Indian Institute of Toxicology Research (Formerly: Industrial Toxicology Research Centre), Post Box No. 80, Mahatma Gandhi Marg, Lucknow 226001 (India)

    2009-12-30

    The ostracod Cypris subglobosa Sowerby, 1840 static bioassay test on the basis of a 48 h of 50% of immobilization (EC{sub 50}) has been used to measure the toxicity of 36 metals and metalloids and 12 reference toxicants. Among the 36 metals and metalloids, osmium (Os) was found to be the most toxic in the test while boron (B), the least toxic. The EC{sub 50} values of this study revealed positive linear relationship with the established test models of cladoceran (Daphnia magna), sludge worm (Tubifex tubifex), chironomid larvae (Chironomus tentans), protozoan (Tetrahymena pyriformis), fathead minnow (Pimephales promelas), bluegill sunfish (Lepomis macrochirus), and aquatic macrophyte duckweed (Lemna minor). Correlation coefficients (r{sup 2}) for 17 physicochemical properties of metals or metal ions and EC{sub 50}s (as pM) were examined by linear regression analysis. The electronegativity, ionization potential, melting point, solubility product of metal sulfides (pK{sub sp}), softness parameter and some other physicochemical characteristics were significantly correlated with EC{sub 50}s of metals to C. subglobosa. The reproducibility of toxicity test was determined using 12 reference toxicants. The coefficient of variability of the EC{sub 50}s ranged from 6.95% to 55.37% and variability was comparable to that noticed for D. magna and other aquatic test models. The study demonstrated the need to include crustacean ostracods in a battery of biotests to detect the presence of hazardous chemicals in soils, sewage sludges, sediments and aquatic systems.

  14. Acute toxicity of metals and reference toxicants to a freshwater ostracod, Cypris subglobosa Sowerby, 1840 and correlation to EC(50) values of other test models.

    Science.gov (United States)

    Khangarot, B S; Das, Sangita

    2009-12-30

    The ostracod Cypris subglobosa Sowerby, 1840 static bioassay test on the basis of a 48h of 50% of immobilization (EC(50)) has been used to measure the toxicity of 36 metals and metalloids and 12 reference toxicants. Among the 36 metals and metalloids, osmium (Os) was found to be the most toxic in the test while boron (B), the least toxic. The EC(50) values of this study revealed positive linear relationship with the established test models of cladoceran (Daphnia magna), sludge worm (Tubifex tubifex), chironomid larvae (Chironomus tentans), protozoan (Tetrahymena pyriformis), fathead minnow (Pimephales promelas), bluegill sunfish (Lepomis macrochirus), and aquatic macrophyte duckweed (Lemna minor). Correlation coefficients (r(2)) for 17 physicochemical properties of metals or metal ions and EC(50)s (as pM) were examined by linear regression analysis. The electronegativity, ionization potential, melting point, solubility product of metal sulfides (pK(sp)), softness parameter and some other physicochemical characteristics were significantly correlated with EC(50)s of metals to C. subglobosa. The reproducibility of toxicity test was determined using 12 reference toxicants. The coefficient of variability of the EC(50)s ranged from 6.95% to 55.37% and variability was comparable to that noticed for D. magna and other aquatic test models. The study demonstrated the need to include crustacean ostracods in a battery of biotests to detect the presence of hazardous chemicals in soils, sewage sludges, sediments and aquatic systems. PMID:19683870

  15. Acute toxicity of metals and reference toxicants to a freshwater ostracod, Cypris subglobosa Sowerby, 1840 and correlation to EC50 values of other test models

    International Nuclear Information System (INIS)

    The ostracod Cypris subglobosa Sowerby, 1840 static bioassay test on the basis of a 48 h of 50% of immobilization (EC50) has been used to measure the toxicity of 36 metals and metalloids and 12 reference toxicants. Among the 36 metals and metalloids, osmium (Os) was found to be the most toxic in the test while boron (B), the least toxic. The EC50 values of this study revealed positive linear relationship with the established test models of cladoceran (Daphnia magna), sludge worm (Tubifex tubifex), chironomid larvae (Chironomus tentans), protozoan (Tetrahymena pyriformis), fathead minnow (Pimephales promelas), bluegill sunfish (Lepomis macrochirus), and aquatic macrophyte duckweed (Lemna minor). Correlation coefficients (r2) for 17 physicochemical properties of metals or metal ions and EC50s (as pM) were examined by linear regression analysis. The electronegativity, ionization potential, melting point, solubility product of metal sulfides (pKsp), softness parameter and some other physicochemical characteristics were significantly correlated with EC50s of metals to C. subglobosa. The reproducibility of toxicity test was determined using 12 reference toxicants. The coefficient of variability of the EC50s ranged from 6.95% to 55.37% and variability was comparable to that noticed for D. magna and other aquatic test models. The study demonstrated the need to include crustacean ostracods in a battery of biotests to detect the presence of hazardous chemicals in soils, sewage sludges, sediments and aquatic systems.

  16. In Vitro Pulmonary Toxicity of Metal Oxide Nanoparticles

    DEFF Research Database (Denmark)

    Cupi, Denisa; Dreher, Kevin

    completely inhibit 25nm TiO2 and 69nm CeO2 NM induction of IL-8, IL-6 and HO-1 gene expression indicating a role of NFκB in these responses. A cell-based ELISA for NFκB p65 phosphorylation revealed rapid Ser536 phosphorylation in BEAS2B cells following exposure to 50 μg/ml of TiO2 and CeO2 NMs with sizes >25...... comprehensive toxicological assessments. BEAS2B human bronchial epithelial cells were employed to assess the in vitro pulmonary toxicity of 4 TiO2 and 4 CeO2 particles varying is size (6 - 1288nm) and crystalline structure. Exposures were conducted over several concentrations for each endpoint examined. No BEAS......2B cytotoxicity was observed for any particle following a 24hr exposure to concentrations upto100 μg/ml. The ability of TiO2 and CeO2 particles to induce inflammation and oxidative stress was assessed by gene induction using RT-PCR. At 50 μg/ml maximal IL-8 and IL-6 gene induction by TiO2 and CeO2...

  17. Comparison of metal toxic impacts between aquatic and terrestrial organisms: is the free ion concentration a sufficient descriptor?

    DEFF Research Database (Denmark)

    Owsianiak, Mikolaj; Rosenbaum, Ralph K.; Larsen, Henrik Fred;

    2011-01-01

    Characterization of metal toxic impacts in comparative risk assessment and life cycle impact assessment (LCIA) should take into account metal speciation and interactions with soil/water organic constituents, because these mechanisms control metal bioavailability and may influence their toxic...... hypothesis that the free metal ion is an appropriate “general”descriptor of metal toxicity. Results for 128 laboratory tests on Daphnia magna exposed to copper ions (Cu2+) in water show that variation of several orders of magnitude are observed between the toxicity tests. These variations may be a result of...... organisms. Up to three orders of magnitude difference occur for the extreme case of barley (Hordeum vulgare). Given the scarcity of terrestrial effect data compared to aquatic data, reliable and transparent, mechanistic-based predictions of terrestrial toxic impacts from aquatic effect data would be an...

  18. Mycorrhizal fungi modulate phytochemical production and antioxidant activity of Cichorium intybus L. (Asteraceae) under metal toxicity.

    Science.gov (United States)

    Rozpądek, P; Wężowicz, K; Stojakowska, A; Malarz, J; Surówka, E; Sobczyk, Ł; Anielska, T; Ważny, R; Miszalski, Z; Turnau, K

    2014-10-01

    Cichorium intybus (common chicory), a perennial plant, common in anthropogenic sites, has been the object of a multitude of studies in recent years due to its high content of antioxidants utilized in pharmacy and food industry. Here, the role of arbuscular mycorrhizal fungi (AMF) in the biosynthesis of plant secondary metabolites and the activity of enzymatic antioxidants under toxic metal stress was studied. Plants inoculated with Rhizophagus irregularis and non-inoculated were grown on non-polluted and toxic metal enriched substrata. The results presented here indicate that AMF improves chicory fitness. Fresh and dry weight was found to be severely affected by the fungi and heavy metals. The concentration of hydroxycinnamates was increased in the shoots of mycorrhizal plants cultivated on non-polluted substrata, but no differences were found in plants cultivated on metal enriched substrata. The activity of SOD and H2O2 removing enzymes CAT and POX was elevated in the shoots of mycorrhizal plants regardless of the cultivation environment. Photochemical efficiency of inoculated chicory was significantly improved. Our results indicate that R. irregularis inoculation had a beneficial role in sustaining the plants ability to cope with the deleterious effects of metal toxicity. PMID:25048909

  19. pH-Dependent metal ion toxicity influences the antibacterial activity of two natural mineral mixtures.

    Directory of Open Access Journals (Sweden)

    Tanya M Cunningham

    Full Text Available BACKGROUND: Recent studies have demonstrated that several mineral products sold for medicinal purposes demonstrate antimicrobial activity, but little is known about the physicochemical properties involved in antibacterial activity. METHODOLOGY/PRINCIPAL FINDINGS: Using in vitro mineral suspension testing, we have identified two natural mineral mixtures, arbitrarily designated BY07 and CB07, with antibacterial activity against a broad-spectrum of bacterial pathogens. Mineral-derived aqueous leachates also exhibited antibacterial activity, revealing that chemical, not physical, mineral characteristics were responsible for the observed activity. The chemical properties essential for bactericidal activity against Escherichia coli were probed by testing antibacterial activity in the presence of metal chelators, the hydroxyl radical scavenger, thiourea, and varying pH levels. Chelation of the BY07 minerals with EDTA or desferrioxamine eliminated or reduced BY07 toxicity, respectively, suggesting a role of an acid-soluble metal species, particularly Fe(3+ or other sequestered metal cations, in mineral toxicity. This conclusion was supported by NMR relaxation data, which indicated that BY07 and CB07 leachates contained higher concentrations of chemically accessible metal ions than leachates from non-bactericidal mineral samples. CONCLUSIONS/SIGNIFICANCE: We conclude that the acidic environment of the hydrated minerals significantly contributes to antibacterial activity by increasing the availability and toxicity of metal ions. These findings provide impetus for further investigation of the physiological effects of mineral products and their applications in complementary antibacterial therapies.

  20. Toxicity of heavy metals and metal-containing nanoparticles on plants.

    Science.gov (United States)

    Mustafa, Ghazala; Komatsu, Setsuko

    2016-08-01

    Plants are under the continual threat of changing climatic conditions that are associated with various types of abiotic stresses. In particular, heavy metal contamination is a major environmental concern that restricts plant growth. Plants absorb heavy metals along with essential elements from the soil and have evolved different strategies to cope with the accumulation of heavy metals. The use of proteomic techniques is an effective approach to investigate and identify the biological mechanisms and pathways affected by heavy metals and metal-containing nanoparticles. The present review focuses on recent advances and summarizes the results from proteomic studies aimed at understanding the response mechanisms of plants under heavy metal and metal-containing nanoparticle stress. Transport of heavy metal ions is regulated through the cell wall and plasma membrane and then sequestered in the vacuole. In addition, the role of different metal chelators involved in the detoxification and sequestration of heavy metals is critically reviewed, and changes in protein profiles of plants exposed to metal-containing nanoparticles are discussed in detail. Finally, strategies for gaining new insights into plant tolerance mechanisms to heavy metal and metal-containing nanoparticle stress are presented. This article is part of a Special Issue entitled: Plant Proteomics - a bridge between fundamental processes and crop production, edited by Dr. Hans-Peter Mock. PMID:26940747

  1. Microencapsulated Aliivibrio fischeri in Alginate Microspheres for Monitoring Heavy Metal Toxicity in Environmental Waters

    Directory of Open Access Journals (Sweden)

    Dedi Futra

    2014-12-01

    Full Text Available In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxicity in waters based on the marine bacterium Aliivibrio fischeri (A. fischeri encapsulated in alginate microspheres is described. Cu(II, Cd(II, Pb(II, Zn(II, Cr(VI, Co(II, Ni(II, Ag(I and Fe(II were selected as sample toxic heavy metal ions for evaluation of the performance of this toxicity microbiosensor. The loss of bioluminescence response from immobilized A. fischeri bacterial cells corresponds to changes in the toxicity levels. The inhibition of the luminescent biosensor response collected at excitation and emission wavelengths of 287 ± 2 nm and 487 ± 2 nm, respectively, was found to be reproducible and repeatable within the relative standard deviation (RSD range of 2.4–5.7% (n = 8. The toxicity biosensor based on alginate micropsheres exhibited a lower limit of detection (LOD for Cu(II (6.40 μg/L, Cd(II (1.56 μg/L, Pb(II (47 μg/L, Ag(I (18 μg/L than Zn(II (320 μg/L, Cr(VI (1,000 μg/L, Co(II (1700 μg/L, Ni(II (2800 μg/L, and Fe(III (3100 μg/L. Such LOD values are lower when compared with other previous reported whole cell toxicity biosensors using agar gel, agarose gel and cellulose membrane biomatrices used for the immobilization of bacterial cells. The A. fischeri bacteria microencapsulated in alginate biopolymer could maintain their metabolic activity for a prolonged period of up to six weeks without any noticeable changes in the bioluminescence response. The bioluminescent biosensor could also be used for the determination of antagonistic toxicity levels for toxicant mixtures. A comparison of the results obtained by atomic absorption spectroscopy (AAS and using the proposed luminescent A. fischeri-based biosensor suggests that the optical toxicity biosensor can be used for quantitative microdetermination of heavy metal toxicity in environmental water samples.

  2. Assessment of occupational exposure to toxic metals in some paint and secondary iron and steel industries in Lagos, Nigeria using TXRF technique

    International Nuclear Information System (INIS)

    The concentration of PM2.5, PM10 and TSP in the work environments of a secondary iron and steel smelting and a paint industry in Lagos, Nigeria, were investigated using gravimetric sampling techniques and TXRF spectrometric analysis. The TXRF was used to analyse the concentration of toxic trace elements and heavy metals in the air-borne particulate. The elements detected included Ti, V, Cr, Mn, Fe, Co, Zn and Pb. Toxicity potentials of PM10 and PM2.5 suspended particulate matter and that of Pb were determined using USEPA national ambient air quality standards. Results were used to evaluate the possible occupational exposure for workers in the sampling areas, as well as those of the general public. These indicate that the concentrations of respirations dust and heavy metals in the work environments, especially the iron and steel smelter are high enough to affect the health of workers and the general public who reside in the neighbourhood. If combined with the effect of traffic pollution in this areas, the total air pollution load may be much higher than values recommended by WHO for general public protection. The need to investigate the options for emission reduction and the management of occupational and general public exposure was highlighted. (author)

  3. Analysis of toxic and heavy metals in cataract extraction from human eyes

    International Nuclear Information System (INIS)

    Surma and many other substances are frequently used for the treatment of eyes and for cosmetic purposes, which may contain large quantities of toxic and heavy metals particularly lead. Toxic metals may also enter into the body through different food chain system and also due to heavy traffic and contaminated dusts in the air of the overcrowded cities. Eyes being exposed part of human body has maximum chances to get in contact with polluted atmosphere. This study has been undertaken to find the role of toxic elements in the formation of cataract in eyes. Samples of eye lenses were collected and carefully digested in 3 ml of conc. HClO/sub 4/ and 1 ml of conc. HNO/sub 3/. Then analysis of Zn, Cd, Pb, Cu, was carried out in 0.02 m HClO/sub 4/ using differential pulse anodic stripping voltametry. Levels of Zn, Cd, Pb and Cu in eye lenses are from 324 - 5746 mug/g, 3 - 240 mug/g, 3 - 240 mug/g, 25 - 120 mug /g and 23 - 485 mug/g, respectively. Chemical composition of ocular fluid indicates that Pb, Cd, Cu, Zn are not present in it normally. In addition to other factors , role of heavy and toxic metals in the formation of cataract cannot be overlooked. Therefore, use of surma and other cosmetics should be discouraged. (author)

  4. Pollution by metals and toxicity assessment using Caenorhabditis elegans in sediments from the Magdalena River, Colombia.

    Science.gov (United States)

    Tejeda-Benitez, Lesly; Flegal, Russell; Odigie, Kingsley; Olivero-Verbel, Jesus

    2016-05-01

    The Magdalena River is the most important river in Colombia, supplying over 70% of the population of fish and drinking water, and it also is the main river transportation way of the country. It receives effluents from multiple sources along its course such as contaminant agricultural and industrial discharges. To evaluate the toxicity profile of Magdalena River sediments through endpoints such as survival, locomotion, and growth, wild type strains of Caenorhabditis elegans were exposed to aqueous extracts of the sediments. To identify changes in gene expression, GFP transgenic strains were used as reporter genes. Physiological and biochemical data were correlated with metal concentration in the sediments, identifying patterns of toxicity along the course of the river. Levels of some metals such as Cd, Cu, and Ni were above TEC and PEC limits. Effects in survival, growth, and locomotion were observed in most of the samples, and changes in gene expression were evident in the genes mtl-2, sod-4, and gst-1 using fluorescence expression. Cadmium and lead were the metals which were primarily associated with sediment toxicity, and the sampling sites with the highest increased expression of stress response genes were Barrancabermeja and Girardot. However, the diverse nature of toxic profiles observed in C. elegans in the study area showed the pervasiveness of different types of discharges throughout the river system. PMID:26851980

  5. Microalgal motility measurement microfluidic chip for toxicity assessment of heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Guoxia [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Department of Biotechnology, Dalian, Liaoning (China); Dalian University, Dalian, Liaoning (China); Wang, Yunhua [Dalian University, Dalian, Liaoning (China); Qin, Jianhua [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Department of Biotechnology, Dalian, Liaoning (China)

    2012-12-15

    A polydimethylsiloxane microfluidic chip has been developed for the estimation of toxic heavy metals based on measurement of mobility of marine microalgae. The chip is mainly composed of an upstream concentration gradient generator and a downstream perfusion-based chemotatic module. The processes of toxic liquid dilution and diffusion, microalgal culturing, cell stimulation, and online screening can be integrated in this chip, which makes it an attractive approach to simplify toxicity testing procedures. The microalgal motility was adopted as a microfluidic bioassay signal and was evaluated as the percentage of motile cells, curvilinear velocity, average path velocity, and straight line velocity. Two mobile marine microalgae, Platymonas subcordiformis and Platymonas helgolandica var. tsingtaoensis, were confined in the chemotatic module and stimulated by the eight concentration gradients of Cu and Cd generated by the concentration gradient generator. In all cases, a toxic response was detected (i.e., a dose-related inhibition of motility was observed). Only 1.5 h was needed to predict EC{sub 50} values. Thus, the microfluidic chip developed was proved to be useful as a simple and rapid approach in heavy metal detection and might be expanded as a conventional test method in environmental toxicity assessment. (orig.)

  6. Contribution of glutathione to the control of cellular redox homeostasis under toxic metal and metalloid stress.

    Science.gov (United States)

    Hernández, Luis E; Sobrino-Plata, Juan; Montero-Palmero, M Belén; Carrasco-Gil, Sandra; Flores-Cáceres, M Laura; Ortega-Villasante, Cristina; Escobar, Carolina

    2015-05-01

    The accumulation of toxic metals and metalloids, such as cadmium (Cd), mercury (Hg), or arsenic (As), as a consequence of various anthropogenic activities, poses a serious threat to the environment and human health. The ability of plants to take up mineral nutrients from the soil can be exploited to develop phytoremediation technologies able to alleviate the negative impact of toxic elements in terrestrial ecosystems. However, we must select plant species or populations capable of tolerating exposure to hazardous elements. The tolerance of plant cells to toxic elements is highly dependent on glutathione (GSH) metabolism. GSH is a biothiol tripeptide that plays a fundamental dual role: first, as an antioxidant to mitigate the redox imbalance caused by toxic metal(loid) accumulation, and second as a precursor of phytochelatins (PCs), ligand peptides that limit the free ion cellular concentration of those pollutants. The sulphur assimilation pathway, synthesis of GSH, and production of PCs are tightly regulated in order to alleviate the phytotoxicity of different hazardous elements, which might induce specific stress signatures. This review provides an update on mechanisms of tolerance that depend on biothiols in plant cells exposed to toxic elements, with a particular emphasis on the Hg-triggered responses, and considering the contribution of hormones to their regulation. PMID:25750419

  7. Acute toxicity modeling of rainbow trout and silver sea bream exposed to waterborne metals.

    Science.gov (United States)

    Liao, C M; Lin, M C

    2001-01-01

    Of three proposed acute toxicity models, the uptake-depuration (UD) model, the time-integrated concentration (TIC) model, and the concentration-time (CT) model are derived and verified with acute toxicity data to estimate the internal residues of waterborne metals in fish as a function of a few constants and variables. The main factors are the exposure time, the external exposure concentration, the bioconcentration factor (BCF), and the depuration rate constant (k2). The UD model is based on the concept of residue levels at the cell membrane well correlating with the whole-body concentrations, whereas the TIC and the CT models are based on the idea of irreversible inhibition of the enzyme acetylcholinesterase (AChE) governing the metal acute toxicity in that metals in the entire fish or in the aqueous phase can be described by the critical area under the time-concentration curve that is associated with a critical TIC of toxicant in the target tissue. A highly significant correlation (r2 > 0.9) was found between predictions and LC50(t) data for both the TIC and the CT models, indicating successfully describe 4- to 18-d LC50(t) data of arsenic (As), cobalt (Co), copper (Cu), and Co/Cu mixture in rainbow trout (Oncorhyuchus mykiss) and of Cu in fingerlings and subadults of silver sea bream (Sparus sarba). The time-dependent lethal internal concentration at the site of action that causes 50% mortality is also predicted for a given compound and species. It concludes that the TIC and the CT models can be applied to regulate the acute toxicity and to estimate incipient LC50 values and internal residues of waterborne metals in fish. PMID:11501285

  8. Airborne sulphur and heavy metal pollution in the environment of a thermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Mankovska, B. (Forestry Research Institute Zvolen, Zvolen (Slovak Republic))

    1994-01-01

    Concentrations of S, As and heavy metals were measured in the samples of spruce and pine needles, beach leaves and mosses at different distances in the study area. The concentrations of all elements are decreased in a coefficient of pollution charge which ranges from 1.5 to 2.2. By supplementing EDX analysis data with microscopy data in the area coal-fly-ash and oil-fly-ash were determined. Emissions of SO[sub 2], As, and heavy metals and solid particulates affected the health state of forest stands.

  9. Chemistry and pharmacological properties of some natural and synthetic antioxidants for heavy metal toxicity.

    Science.gov (United States)

    Flora, S J S; Shrivastava, Rupal; Mittal, Megha

    2013-01-01

    Heavy metals are known to cause oxidative deterioration of bio-molecules by initiating free radical mediated chain reaction resulting in lipid per-oxidation, protein oxidation and oxidation of nucleic acid like DNA and RNA. The development of effective dual functioning antioxidants, possessing both metal-chelating and free radical-scavenging properties should bring into play. Administration of natural and synthetic antioxidants like, quercetin, catechin, taurine, captopril, gallic acid, melatonin, N-acetyl cysteine, α- lipoic acid and others have been recognized in the disease prevention and clinical recovery against heavy metal intoxication. These antioxidants affect biological systems not only through direct quenching of free radicals but also via chelation of toxic metal(s). These antioxidants also, have the capacity to enhance cellular antioxidant defense mechanism by regenerating endogenous antioxidants, such as glutathione and vitamin C and E. They also influence cellular signaling and trigger redox sensitive regulatory pathways. The reactivity of antioxidants in protecting against heavy metal induced oxidative stress depends upon their structural properties, their partitioning abilities between hydrophilic and lipophilic environment and their hydrogen donation antioxidant properties. Herein, we review the structural, biochemical and pharmacological properties of selected antioxidants with particular reference to their ability to (i) chelate heavy metals from its complex (ii) ameliorate free radical (iii) terminate heavy metal induced free radical chain reaction (iv) regenerate endogenous antioxidants and, (v) excretion of metal without its redistribution. PMID:24206124

  10. Dynamics of Metal Partitioning at the Cell-Solution Interface: Implications for Toxicity Assessment under Growth-Inhibiting Conditions.

    Science.gov (United States)

    Duval, Jérôme F L; Paquet, Nathalie; Lavoie, Michel; Fortin, Claude

    2015-06-01

    Metal toxicity toward microorganisms is usually evaluated by determining growth inhibition. To achieve a mechanistic interpretation of such toxic effects, the intricate coupling between cell growth kinetics and metal partitioning dynamics at the cell-solution interface over time must be considered on a quantitative level. A formalism is elaborated to evaluate cell-surface-bound, internalized, and extracellular metal fractions in the limit where metal uptake kinetics is controlled by internalization under noncomplexing medium conditions. Cell growth kinetics is tackled using the continuous logistic equation modified to include growth inhibition by metal accumulation to intracellular or cell surface sites. The theory further includes metal-proton competition for adsorption at cell-surface binding sites, as well as possible variation of cell size during exposure to metal ions. The formalism elucidates the dramatic impacts of initial cell concentration on metal bioavailability and toxicity over time, in agreement with reported algae bioassays. It further highlights that appropriate definition of toxicity endpoints requires careful inspection of the ratio between exposure time scale and time scale of metal depletion from bulk solution. The latter depends on metal internalization-excretion rate constants, microorganism growth, and the extent of metal adsorption on nonspecific, transporter, and growth inhibitory sites. As an application of the theory, Cd toxicity in the algae Pseudokirchneriella subcapitata is interpreted from constrained modeling of cell growth kinetics and of interfacial Cd-partitioning dynamics measured under various exposure conditions. PMID:25945520

  11. Evaluation of toxic heavy metals in ayurvedic syrups sold in local markets of hazara, pakistan

    International Nuclear Information System (INIS)

    Herbal and Ayurvedic preparations, widely used in Pakistan and the developing world, present serious risk of heavy metal toxicity related to their medicinal content and prolonged use by patients. The objective of this study was to find out the concentration of heavy metals in Herbal and Ayurvedic liquid preparations commonly used for treatment of different diseases, from local markets of Hazara. Methods: The cross sectional survey of traditional herbal and Ayurvedic medicine shops included ten liquid preparations selected from local shops of Mansehra and Abbottabad after interviewing the shopkeepers; so as to select the most commonly sold preparations along with their indications. All samples were analysed on standard Atomic Absorption Spectroscopy for qualitative and quantitative study of toxic heavy metals (Mercury, Iron, Zinc, Lead, Manganese and Arsenic). Results: Toxic levels of Mercury were present in seven syrups, i.e., (Kashneeze, Akseer e Pachas, Tankar, Sharbat e folad, Urosinal, Akseer e Jigar and Amrat dhara) while Arsenic was present only in Urosinal. Iron, Zinc, Manganese and Lead were present in permissible limits in all syrups. Conclusion: Mercury and Arsenic are present in local Herbal and Ayurvedic liquid preparations far beyond the permissible limits as proposed by the International Regulatory Authorities for health drugs while the rest of metals, i.e., Zinc, Manganese, and Iron are within the therapeutic limits. (author)

  12. Assessment of toxicity reduction after metal removal in bioleached sewage sludge.

    Science.gov (United States)

    Renoux, A Y; Tyagi, R D; Samson, R

    2001-04-01

    Sewage sludge can be applied to land to supply and recycle organic matter and nutrients. Trace elements in sludge, however, may accumulate in the soil with repeated sludge applications. Reducing metal content may therefore reduce the adverse effects of sludge application. The objective of this study was to evaluate the efficiency of bioleaching technology in reducing metal content and toxicity as measured by a battery of terrestrial and liquid-phase bioassays. Sludge-soil mixtures simulating the application of sludge to land were tested by means of terrestrial bioassays, barley (Hordeum vulgare L.) seed germination (5 d) and sprout growth (14 d), lettuce (Lactuca sativa) seed germination (5 d), and worm (Eisenia andrei) mortality (14 d). Liquid-phase bioassays, Microtox (Vibrio fischeri, 15 min), lettuce root elongation (L. sativa, 5 d), cladoceran mortality (Daphnia magna, 48 h), and SOS Chromotest (Escherichia coli) were used after elutriation of the sludge. Comparison of the bioassay results (except for D. magna) before and after treatment demonstrated that this bioleaching process reduced both sludge toxicity and metal content. In addition, lower Cu and Zn concentrations found in barley sprouts following treatment supported the assumption that the bioleaching process, by decreasing metal content and bioavailability, reduced sewage sludge toxicity. This study also emphasized the interest of using ecotoxicological bioassays for testing biosolids. In particular, the terrestrial bioassays after simulation of land application and the Microtox test after sludge elutriation proved to be the most appropriate procedures. PMID:11317888

  13. Airborne heavy metal pollution in the environment of a danish steel plant

    DEFF Research Database (Denmark)

    Vestergaard, N. K.; Stephansen, U.; Rasmussen, L.;

    1986-01-01

    to electric-arc furnaces. The samples were analyzed for Cd, Cr, Cu, Fe, Mn, Pb and Zn.The results show that heavy metal pollution from the steelworks still is severe and that it follows a decreasing power curve when the distance to the steelworks is increased. However, a reduction in the deposition of heavy...

  14. Platinum group metals in airborne particulate matter of Ostrava city, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Sikorová, L.; Šucmanová, M.; Mikuška, Pavel; Wiltsche, H.; Štěpnička, J.

    Sofia: STEF92 Technology Ltd., 2013, s. 741-748. ISBN 978-619-7105-03-2. ISSN 1314-2704. [International Multidisciplinary Scientific Geoconference SGEM 2013 /13./. Albena (BG), 16.06.2013-22.06.2013] Institutional support: RVO:68081715 Keywords : platinum group metals * transport * air pollution * urban Subject RIV: CB - Analytical Chemistry, Separation

  15. An in vitro method to assess toxicity of waterborne metals to fish

    International Nuclear Information System (INIS)

    The transcription of metal-responsive genes in the rainbow trout (Oncorhynchus mykiss) gill tissue can be used to detect effects of bioreactive metals in natural waters. Here we take advantage of an in vitro gill epithelium, which can be directly exposed to test water samples. The in vitro gill epithelial model mimics the molecular response of in vivo gill epithelial cells to waterborne contaminants. The same culture system can detect trace metals and organic waterborne contaminants. Furthermore, combining this epithelial model with transcriptomic profiling yields an extremely discriminatory biomonitoring tool able to detect and differentiate waterborne metal contaminants. The bioreactive fraction of metal in the water sample is detected using the cells naturally occurring metal sensor, metal-responsive transcription factor 1 (MTF1), which acts upon Metal Response Elements (MRE's) in the enhancer region of metal regulated genes. Induction of the MTF1 responsive genes, metallothionein-A (MTA), metallothionein-B (MTB), and zinc transporter 1 (ZnT-1) in the cell culture was strongly dependent of the concentrations of bioreactive zinc and silver in the test water. Importantly, gene expression in cell culture reflected animal toxicity, measured as inhibition of Ca2+ and Na+ influx, in live rainbow trout exposed to the same waters. A cDNA microarray was deployed to determine the differential profiles of transcripts characteristic of exposure to silver, copper or cadmium within this in vitro system. These experiments illustrated the potential power of combining the in vitro gill model epithelium with genetic profiling for accurate characterisation and identification of bioreactive toxicants in waterborne samples

  16. Assessment of toxicity of heavy metal contaminated soils for Collembola in the field and laboratory

    DEFF Research Database (Denmark)

    Xu, Jie; Krogh, Paul Henning; Luo, Yongming;

    2008-01-01

    We present a field and laboratory investigation of effects of increasing levels of heavy metal contamination on the biodiversity and performance of collembolans. A 40 year old pollution with Cu, Zn, Pb and Cd pollution due to Cu smelting over 40 years was investigated in a paddy field area of...... Zhejiang province, Fuyang county. We addressed the questions: 1) how do different collembolan life-forms respond to heavy metals in long-time pollution field site. 2) Are laboratory toxicity testing of field collected polluted soil predictable for the population effects observed in aged heavy metal...... pollutions. Effects of the heavy metals in the soil from the paddy fields were assessed for growth, survival and reproduction under laboratory conditions. For the tests we used two soil arthropod species: the parthenogenetic, Folsomia candida Willem 1902, and the sexually reproducing, Sinella curviseta Brook...

  17. Natural airborne dust and heavy metals: a case study for kermanshah, Western iran (2005-2011.

    Directory of Open Access Journals (Sweden)

    Meghdad Pirsaheb

    2015-04-01

    Full Text Available Dust pollution has become a serious environmental problem especially in recent decades. The present study aim was the investigation of the levels of PM10 concentration in Kermanshah, western Iran and also measured five important heavy metals (Pb, Cd, As, Hg and Cr in some samples during 2005 to 2011.A total 2277 samples were collected from air pollution measurement station belonging to the Department of Environment in Kermanshah. Furthermore, four samples were collected during dusty days to determine the selected heavy metals concentration. The samples were analyzed statistically using the SPSS Ver.16.The highest seasonal average concentration in spring was recorded in 2008 with 216.63μg/m(3, and the maximum values of 267.79 and 249.09μg/m(3 were observed in summer and winter in 2009, respectively. The maximum concentration of 127.1μg/m(3 was in autumn in 2010. The metals concentration (Pb, Cd, As, Hg and Cr of samples were 42.32±5.40, 37.45±9.29, 3.51±2.07, 1.88±1.64 and 0μg/g in July, 2009, respectively.According to National Ambient Air Quality of USEPA guidelines, the most days with non-standard, warning, emergency and critical conditions were related to 2009 (120 days while the least polluted days were recorded in 2006 (16 days. There are concerns about the increasing frequency and intensity trend of dust storms in recent years as a result of special condition in neighboring Western countries which it could endanger public health and environment. All measured heavy metals except mercury was higher than the standard level of WHO and USEPA.

  18. Determination of toxic metals in different brand of chocolates and candies, marketed in Pakistan

    International Nuclear Information System (INIS)

    In present study three toxic metals, cadmium (Cd), nickel (Ni) and lead (Pb) were determined in chocolates and candy samples available in local markets of Hyderabad, Pakistan. Concentrations of understudy toxic metals (TMs) were determined by electro thermal atomic absorption spectrometry (ETAAS) prior to microwave assisted acid digestion. Validation of the methodology was performed by standard addition method and conventional acid digestion on electric hot plate to obtained TMs concentration, for comparative purpose to obtain results within the 95% confidence level. No significant differences were observed for TMs obtained from both methods (P 0.05). The concentration of Cd, Ni and Pb were observed in chocolates and candy samples is ranged as of 0.099 - 0.353, 1.45 - 4.33 and 1.11 - 2.48 mu g/g, respectively. The results indicated that cocoa-based chocolates have higher contents of TMs than milk- based chocolates and candies. (author)

  19. The Liquid-Liquid Extraction of Toxic Metals (Cd, Hg and Pb by Calixarenes

    Directory of Open Access Journals (Sweden)

    D. Max Roundhill

    2009-12-01

    Full Text Available Toxic metals (Cd, Hg and Pb are mostly present in the environment due to natural phenomenon and human activities as well. Exposure of these non-essential elements in the environment causes severe effects. They are known to cause problems in humans as well as in aquatic life. In this work, we demonstrate various studies regarding liquid-liquid extraction of selected ions with different functionalized calixarenes. This review article briefly discusses several molecular designs of calixarenes for divalent ion (Cd2+, Hg2+ and Pb2+ recognition; as well as the relationship between structure and selectivity of the macrocycles is elaborated. The article does not, however, attempt to cover all of the different approaches to these toxic metal ions extraction.

  20. Liposomes as biological carriers: new therapeutic approaches to metal toxicity and malignant tumors

    International Nuclear Information System (INIS)

    This section contains a summary of research on the development of a new technique of drug encapsulation within liposomes to deliver metal chelating agents and antitumor drugs to specified target organs in order to enhance the therapeutic effect and reduce the effective dosage and toxicity of the drug. It has been demonstrated, that by manipulating the size and lipid composition of liposomes, selective delivery of liposome-encapsulated metal chelators to either the parenchymal or the Kupffer cells of the liver can be achieved

  1. The fate of airborne lead pollution in boreal forest soils

    OpenAIRE

    Klaminder, Jonatan

    2005-01-01

    Lead has a more than three-millennia-long pollution history in Europe. Metal production, burning of coal and use of leaded petrol resulted in a significant pollution of the atmosphere. As a consequence of atmospheric fallout, the Swedish boreal forest is strongly contaminated by airborne lead pollution. High levels of lead in the soil and soil pore water are of concern because the soil fauna, plants and aquatic biota may respond negatively to this toxic element. The fate of the accumulated po...

  2. Novel Strategies for the Removal of Toxic Metals from Soils and Waters

    Science.gov (United States)

    Roundhill, D. Max

    2004-02-01

    This article surveys the toxicities of mercury, cadmium, lead, copper, cadmium, and the actinides. Strategies for the removal of these metals include surfactants, aqueous biphasic systems, and liquid membranes. For soils, both in situ stabilization and detection are discussed. For extraction from soils, electrokinetic extraction, phytoremediation, and bioremediation methods are critically evaluated. This article provides an educator with the resources to set up a series of lectures on inorganic aspects of environmental chemistry.

  3. Leaching assessments of toxic metals in waste plasma display panel glass

    OpenAIRE

    M. Chen; Jiang, P.; Chen, H.; Ogunseitan, OA; Li, Y.

    2015-01-01

    © 2015 A&WMA. The plasma display panel (PDP) is rapidly becoming obsolete, contributing in large amounts to the electronic waste stream. In order to assess the potential for environmental pollution due to hazardous metals leached from PDP glass, standardized leaching procedures, chemical speciation assessments, and bioavailability tests were conducted. According to the Toxicity Characteristic Leaching Procedure (TCLP), arsenic in back glass was present at 4.46 ± 0.22 mg/L, close to its regula...

  4. Assessment of levels and 'health-effects' of airborne particulate matter in mining, metal refining and metal working industries using nuclear and related analytical techniques

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) has been supporting, over the years, several coordinated research programmes (CRPs) on various research topics related to environmental issues impacting human health. The primary aim of these CRPs has been to help enhance the research and development capabilities in the Member States, particularly among developing countries; to identify the sources of various environmental contaminants and evaluate their fate; and to provide for the basis of improved health among human populations by the use of nuclear and related analytical techniques. The CRP on Assessment of Levels and Health-Effects of Airborne Particulate Matter in Mining, Metal Refining and Metal Working Industries using nuclear and related analytical techniques focused on improving the competence for research on workplace monitoring in a variety of industrial environments. The personal monitoring of the APM (airborne particulate matter) of the exposed workforce was carried out for the first time by many participants. Nuclear and related analytical techniques, including the application of proton micro-beam, were used to generate the trace element concentration profiles in various biomarkers tissues of the exposed workers. The quality assurance/quality control (QA/QC) aspects related to the CRP were addressed through intercomparison analyses of APM on filter paper samples and freeze dried human urine samples to generate validated data. These data have helped to generate correlations between the occupational exposure measured and the magnitude of the biological response. Such new information is essential to evolve procedures to considerably reduce/eliminate the pollutants in the workplace environment and to make informed decisions on the evolution of standards in working environments aimed at preserving the health of workers. The purpose of this TECDOC is to provide an overview of the activities performed under the CRP by the participants. The overall achievements

  5. Effects of artificial sweeteners on metal bioconcentration and toxicity on a green algae Scenedesmus obliquus.

    Science.gov (United States)

    Hu, Hongwei; Deng, Yuanyuan; Fan, Yunfei; Zhang, Pengfei; Sun, Hongwen; Gan, Zhiwei; Zhu, Hongkai; Yao, Yiming

    2016-05-01

    The ecotoxicity of heavy metals depends much on their speciation, which is influenced by other co-existing substances having chelating capacity. In the present study, the toxic effects of Cd(2+) and Cu(2+) on a green algae Scenedesmus obliquus were examined in the presence of two artificial sweeteners (ASs), acesulfame (ACE) and sucralose (SUC) by comparing the cell specific growth rate μ and pulse-amplitude-modulated (PAM) parameters (maximal photosystem II photochemical efficiency Fv/Fm, actual photochemical efficiency Yield, and non-photochemical quenching NPQ) of the algae over a 96-h period. Simultaneously, the bioconcentration of the metals by the algal cells in the presence of the ASs was measured. The presence of ACE enhanced the growth of S. obliquus and promoted the bioconcentration of Cd(2+) in S. obliquus, while the impacts of SUC were not significant. Meanwhile, EC50 values of Cd(2+) on the growth of S. obliquus increased from 0.42 mg/L to 0.54 mg/L and 0.48 mg/L with the addition of 1.0 mg/L ACE and SUC, respectively. As for Cu(2+), EC50 values increased from 0.13 mg/L to 0.17 mg/L and 0.15 mg/L with the addition of 1.0 mg/L ACE and SUC, respectively. In summary, the two ASs reduced the toxicity of the metals on the algae, with ACE showing greater effect than SUC. Although not as sensitive as the cell specific growth rate, PAM parameters could disclose the mechanisms involved in metal toxicity at subcellular levels. This study provides the first evidence for the possible impact of ASs on the ecotoxicity of heavy metals. PMID:26915590

  6. Toxicity of metal-contaminated sediments from Keswick Reservoir, California, USA

    Energy Technology Data Exchange (ETDEWEB)

    Finlayson, B.; Fujimura, R.; Huang, Z.Z.

    2000-02-01

    Keswick Reservoir, California, USA, receives metal-laden acid-mine drainage (AMD) from the abandoned Iron Mountain Mine. Mixing of the AMD with reservoir water causes precipitation and deposition of metal-rich sludge in the reservoir. Hydroelectric generation activities can scour the sediments and mobilize trace metals cadmium, copper, and zinc into the water column, thus creating potentially toxic conditions to fish and aquatic invertebrates. Sediment samples collected from Keswick Reservoir in 1993 and 1994 were analyzed for acid-volatile sulfides and for simultaneously extractable metals (SEM), and whole sediments and sediment elutriates were tested for toxicity to rainbow trout (Oncorhynchus mykiss), amphipods (Hyalella azteca), and cladocerans (Ceriodaphnia dubia). Acid-volatile sulfide concentrations in the sediments were low (<10 {micro}mol/g H{sub 2}S), indicating that dissolved metals in the sediment pore water were not limited by sulfide. The SEM concentrations were generally high (up to 11 {micro}g/g Cd, 4,800 {micro}g/g Cu, and 1,600 {micro}g/g Zn, dry weight) in the sediments. Whole sediments and 20% w/w sediment elutriates from 16 sites were tested for toxicity. Low survival (as low as 0{degree}) in whole sediments was generally associated with copper and zinc, and to a lesser extent cadmium, concentrations that exceeded probable effect level values for freshwater sediments; survival also may have been influenced by low pH and alkalinity conditions. Low survival (as low as 0%) in sediment elutriates was also generally associated with higher concentrations of dissolved zinc. Further study is required to formulate sediment cleanup levels that are protective of fish and wildlife. Source control in the Iron Mountain Mine drainage will eventually significantly lessen the production of sediments.

  7. Influence of glyphosate and its formulation (Roundup[reg]) on the toxicity and bioavailability of metals to Ceriodaphnia dubia

    International Nuclear Information System (INIS)

    This study examined the toxicological interaction between glyphosate (or its formulation, Roundup[reg]) and several heavy metals to a freshwater cladoceran, Ceriodaphnia dubia. We demonstrated that all binary combinations of Roundup[reg] and metals (Cd, Cu, Cr, Ni, Pb, Se and Zn) exhibited 'less than additive' mixture toxicity, with 48-h LC50 toxic unit>1. Addition of glyphosate alone could significantly reduce the acute toxicity of Ag, Cd, Cr, Cu, Ni, Pb and Zn (but not Hg and Se). The ratio between glyphosate and metal ions was important in determining the mitigation of metal toxicity by glyphosate. A bioaccumulation study showed that in the presence of glyphosate the uptake of some metals (e.g. Ag) was halted but that of others (e.g. Hg) was increased significantly. Therefore, our study strongly suggests that glyphosate and its commercial formulations can control the toxicity as well as the bioavailability of heavy metals in aquatic ecosystems where both groups of chemicals can co-occur. - Glyphosate can control the toxicity and bioavailability of many heavy metals in the aquatic environment

  8. Heavy Metals and Human Health: Mechanistic Insight into Toxicity and Counter Defense System of Antioxidants

    Science.gov (United States)

    Jan, Arif Tasleem; Azam, Mudsser; Siddiqui, Kehkashan; Ali, Arif; Choi, Inho; Haq, Qazi Mohd. Rizwanul

    2015-01-01

    Heavy metals, which have widespread environmental distribution and originate from natural and anthropogenic sources, are common environmental pollutants. In recent decades, their contamination has increased dramatically because of continuous discharge in sewage and untreated industrial effluents. Because they are non-degradable, they persist in the environment; accordingly, they have received a great deal of attention owing to their potential health and environmental risks. Although the toxic effects of metals depend on the forms and routes of exposure, interruptions of intracellular homeostasis include damage to lipids, proteins, enzymes and DNA via the production of free radicals. Following exposure to heavy metals, their metabolism and subsequent excretion from the body depends on the presence of antioxidants (glutathione, α-tocopherol, ascorbate, etc.) associated with the quenching of free radicals by suspending the activity of enzymes (catalase, peroxidase, and superoxide dismutase). Therefore, this review was written to provide a deep understanding of the mechanisms involved in eliciting their toxicity in order to highlight the necessity for development of strategies to decrease exposure to these metals, as well as to identify substances that contribute significantly to overcome their hazardous effects within the body of living organisms. PMID:26690422

  9. Pollution of the Begej Canal sediment--metals, radioactivity and toxicity assessment.

    Science.gov (United States)

    Dalmacija, B; Prica, M; Ivancev-Tumbas, I; van der Kooij, A; Roncevic, S; Krcmar, D; Bikit, I; Teodorovic, I

    2006-07-01

    The Begej Canal is one among a large number of canals in Vojvodina (Northern Province of Serbia and Montenegro). The paper describes a study of metal and radioactivity contamination of the Begej Canal sediment. It is also concerned with the evaluation of sediment acute toxicity based on standard test species Daphnia magna and simultaneously extracted metals and acid volatile sulfides. The quality of sediment was assessed according to Dutch standards, but the results were also compared with some Canadian and USEPA (United States Environmental Protection Agency) guidelines for sediment quality. The results showed severe pollution with chromium, copper, cadmium and zinc, whereby the anthropogenic origin of these contaminants was indicated. The tests of toxicity of sediment pore water to D. magna, gave no indication of the presence of substances in acutely toxic concentrations to this species. It can be speculated that, despite of high metal contents, the observed toxicity was low because of the high contents of clay and iron, as well as sulphide. Also, based on a comparison with the Danube sediment and Vojvodina soil in general, the data of the Begej sediment contamination with 238U and 137Cs. The 137Cs data were used for approximate dating of the sediment. No traces of contamination by nuclear power plants in the region were found, while the presence of technologically enhanced naturally occurring radioactive materials (TENORM) was proved. Conclusions based on different criteria for sediment quality assessment were in some cases contradictory. Study also showed that radioactivity aspects can be useful in sediment quality surveys. The obtained results will be invaluable for the future activities regarding integrated water management based on EC Water Framework Directive (2000/60/EC) in the Danube basin, and particularly in the region of crossborder water body of the Begej Canal. PMID:16527352

  10. Seawater temperature effect on metal accumulation and toxicity in the subantarctic Macquarie Island isopod, Exosphaeroma gigas.

    Science.gov (United States)

    Lewis, Alexander; King, Catherine K; Hill, Nicole A; Cooper, Ashley; Townsend, Ashley T; Mondon, Julie A

    2016-08-01

    Very little is currently known of subantarctic nearshore invertebrates' sensitivity to environmental metals and the role of temperature in this relationship. This study investigated Cu and Zn toxicity in the common subantarctic intertidal isopod, Exosphaeroma gigas, and the influence of temperature on Cu toxicity and bioaccumulation kinetics. Adult E. gigas are insensitive to Cu and Zn at concentrations of 3200 and 7400μg/L respectively in non-renewal tests at 5.5°C (ambient subtidal temperature) over 14days. Under renewed exposures over the same temperature and time period the LC50 for copper was 2204μg/L. A 10-fold increase in Cu body burden occurred relative to zinc, indicating E. gigas has different strategies for regulating the two metals. Copper toxicity and time to mortality both increased with elevated temperature. However, temperature did not significantly affect Cu uptake rate and efflux rate constants derived from biodynamic modelling at lower Cu concentrations. These results may be attributable to E. gigas being an intertidal species with physiological mechanisms adapted to fluctuating environmental conditions. Cu concentrations required to elicit a toxicity response indicates that E. gigas would not be directly threatened by current levels of Cu or Zn present in Macquarie Island intertidal habitats, with the associated elevated temperature fluctuations. This study provides evidence that the sensitivity of this subantarctic intertidal species to metal contaminants is not as high as expected, and which has significance for the derivation of relevant guidelines specific to this distinct subpolar region of the world. PMID:27367827

  11. Evaluation of the factors governing metal biosorption and metal toxicity in acidic soil isolates

    International Nuclear Information System (INIS)

    This research project was designed to determine the feasibility of microbial biosorption processes for removing metal ions from aqueous systems. A culture of acidic soil actinomycetes, grown in an aerobic environment in a completely mixed, semibatch culture reactor, was used for the study. The experiments were based on removal of copper and lead from test solutions. The anionic systems tested were nitrate, sulfate, and chloride. To determine the factors influencing biosorption and to characterize metal uptake by cellular and extracellular components of the microbial system, a dialysis testing procedure was developed. The effectiveness of biosorption was influenced by pH, initial concentration of metals, type of anionic system, and organic content of the system. respirometric runs were carried out to identify potential inhibitory effects of metal accumulation on microbial activities. In general, metal accumulation resulted in a decrease in the microbial oxygen uptake rate. Also, a lag phase was observed before the onset of the respiratory activity particularly at concentrations of copper and lead greater than 100 ppM

  12. Bio-functionalized silver nanoparticles for selective colorimetric sensing of toxic metal ions and antimicrobial studies

    Science.gov (United States)

    Vinod Kumar, V.; Anbarasan, S.; Christena, Lawrence Rene; SaiSubramanian, Nagarajan; Philip Anthony, Savarimuthu

    2014-08-01

    Hibiscus Sabdariffa (Gongura) plant extracts (leaves (HL) and stem (HS) were used for the first time in the green synthesis of bio-functionalized silver nanoparticles (AgNPs). The bio-functionality of AgNPs has been successfully utilized for selective colorimetric sensing of potentially health and environmentally hazardous Hg2+, Cd2+ and Pb2+ metal ions at ppm level in aqueous solution. Importantly, clearly distinguishable colour for all three metal ions was observed. The influence of extract preparation condition and pH were also explored on the formation of AgNPs. Both selectivity and sensitivity differed for AgNPs synthesized from different parts of the plant. Direct correlation between the stability of green synthesized AgNPs at different pH and its antibacterial effects has been established. The selective colorimetric sensing of toxic metal ions and antimicrobial effect of green synthesized AgNPs demonstrated the multifunctional applications of green nanotechnology.

  13. Occurrence of Multidrug-Resistant and Toxic-Metal Tolerant Enterococci in Fresh Feces from Urban Pigeons in Brazil

    OpenAIRE

    da Silva, Vânia Lúcia; Caçador, Natália Cândido; dos Santos Fernandes da Silva, Carolina; Fontes, Cláudia Oliveira; Garcia, Gizele Duarte; Nicoli, Jacques Robert; Diniz, Cláudio Galuppo

    2011-01-01

    Enterococcus are emerging as important putative pathogens resistant to chemicals that are widely released into the environment, and urban pigeons might act as a natural reservoir contributing to the spread of resistant strains. This study aimed to evaluate the occurrence of Enterococcus in pigeon feces and their antimicrobial and toxic metal susceptibility. Bacteria were isolated and identified from 150 fresh feces by phenotypic and genetic techniques. Antimicrobial and toxic metal susceptibi...

  14. Influences of sediment geochemistry on metal accumulation rates and toxicity in the aquatic oligochaete Tubifex tubifex

    OpenAIRE

    Mendez-Fernandez, L; De Jonge, M.; Bervoets, L.

    2014-01-01

    Metal bioaccumulation and toxicity in the aquatic oligochaete Tubifex tubifex exposed to three metal-contaminated field-sediments was studied in order to assess whether sediment-geochemistry (AVS, TOC) plays a major role in influencing these parameters, and to assess if the biodynamic concept can be used to explain observed effects in T. tubifex tissue residues and/or toxicity. An active autotomy promotion was observed in three studied sediments at different time points and reproduction impai...

  15. A high-performance "sweeper" for toxic cationic herbicides: an anionic metal-organic framework with a tetrapodal cage.

    Science.gov (United States)

    Jia, Yan-Yuan; Zhang, Ying-Hui; Xu, Jian; Feng, Rui; Zhang, Ming-Shi; Bu, Xian-He

    2015-12-21

    This communication reports a novel metal-organic framework exhibiting an excellent performance in adsorbing small toxic cationic herbicides, i.e. methyl viologen and diquat, with large adsorption capacities and ultratrace residue levels. To the best of our knowledge, this is the first example of high-performance MOFs trapping toxic cationic herbicides. PMID:26468513

  16. Metals in sediments: bioavailability and toxicity in a tropical reservoir used for public water supply.

    Science.gov (United States)

    Cardoso-Silva, Sheila; Da Silva, Daniel Clemente Vieira Rego; Lage, Fernanda; de Paiva, Teresa Cristina Brazil; Moschini-Carlos, Viviane; Rosa, André Henrique; Pompêo, Marcelo

    2016-05-01

    Sediments may be a repository of contaminants in freshwater ecosystems. One way to assess the quality of this compartment, in terms of potentially bioavailable metals, is by the analysis of acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM). In order to investigate the bioavailability, toxicity, and compartmentalization of different metals (Cd, Cr, Cu, Ni, Pb, Zn), sampling of surface sediments was performed at nine stations along the Paiva Castro reservoir (São Paulo, Brazil). The metals were analyzed using atomic absorption spectroscopy. Sediment organic matter (OM), organic carbon (OC), and grain size were also measured. The parameters pH, EH, temperature, and dissolved oxygen were determined at the sediment-water interface. Chronic and acute toxicological tests were performed with sediments from the area where water was extracted for the public water supply. Low levels of OM, associated with loss of stratification in the water column, explained the relatively low AVS values. The molar ratio ∑[SEM]-[AVS]/fOC was less than 130 mmol/kg(-1) for all the sampling stations, indicating that the metals were not bioavailable. With the exception of Cd, metal levels were in accordance with background concentrations and the threshold effect level (TEL) established by the Canadian Council of Ministers of the Environment. The ecotoxicological tests confirmed the absence of toxic effects to biota. Application of principal component analysis indicated the presence of four compartments along the reservoir: (1) a riverine zone, potentially threatened by contamination with Cd; (2) an intermediate zone; (3) a limnic area; and (4) the area where water was taken for the public water supply. PMID:27117444

  17. Comparison of heavy metal toxicity in continuous flow and batch reactors

    Science.gov (United States)

    Sengor, S. S.; Gikas, P.; Moberly, J. G.; Peyton, B. M.; Ginn, T. R.

    2009-12-01

    The presence of heavy metals may significantly affect microbial growth. In many cases, small amounts of particular heavy metals may stimulate microbial growth; however, larger quantities may result in microbial growth reduction. Environmental parameters, such as growth pattern may alter the critical heavy metal concentration, above which microbial growth stimulation turns to growth inhibition. Thus, it is important to quantify the effects of heavy metals on microbial activity for understanding natural or manmade biological reactors, either in situ or ex situ. Here we compare the toxicity of Zn and Cu on Arthrobacter sp., a heavy metal tolerant microorganism, under continuous flow versus batch reactor operations. Batch and continuous growth tests of Arthrobacter sp. were carried out at various individual and combined concentrations of Zn and Cu. Biomass concentration (OD) was measured for both the batch and continuous reactors, whereas ATP, oxygen uptake rates and substrate concentrations were additionally measured for the continuous system. Results indicated that Cu was more toxic than Zn under all conditions for both systems. In batch reactors, all tested Zn concentrations up to 150 uM showed a stimulatory effect on microbial growth. However, in the case of mixed Zn and Cu exposures, the presence of Zn either eliminated (at the 50 uM level both Zn and Cu) or reduced by ~25% (at the 100 and 150 uM levels both Zn and Cu) the Cu-induced inhibition. In the continuous system, only one test involved combined Cu (40uM) and Zn (125uM) and this test showed similar results to the 40uM Cu continuous test, i.e., no reduction in inhibition. The specific ATP concentration, i.e., ATP/OD, results for the continuous reactor showed an apparent recovery for both Cu-treated populations, although neither the OD nor glucose data showed any recovery. This may reflect that the individual microorganisms that survived after the addition of heavy metals, kept maintaining the usual ATP

  18. Bioavailability assessment of essential and toxic metals in edible nuts and seeds.

    Science.gov (United States)

    Moreda-Piñeiro, Jorge; Herbello-Hermelo, Paloma; Domínguez-González, Raquel; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2016-08-15

    Bioavailability of essential and toxic metals in edible nuts and seeds has been assessed by using an in vitro dialyzability approach. The samples studied included walnuts, Brazil nuts, Macadamia nuts, pecans, hazelnuts, chestnuts, cashews, peanuts, pistachios and seeds (almond, pine, pumpkin and sunflower). Metals were measured by inductively coupled plasma-mass spectrometry in dialyzates and also in samples after a microwave assisted acid digestion pre-treatment. Low dialyzability percentages were found for Al, Fe and Hg; moderate percentages were found for Ba, Ca, Cd, Co, Cu, K, Li, Mg, Mn, Mo, P, Pb, Se, Sr, Tl and Zn; and high dialyzability ratios were found for As, Cr and Ni. The highest dialyzability percentages were found in raw chestnuts and raw hazelnuts. Metal dialyzability was found to be negatively affected by fat content. Positive correlation was found between carbohydrate content and metal dialyzability ratios. Protein and dietary fibre content did not influence metal bioavailability. Predicted dialyzability for some metals based on fat and protein content could also be established. PMID:27006225

  19. An integrated model describing the toxic responses of Daphnia magna to pulsed exposures of three metals.

    Science.gov (United States)

    Hoang, Tham C; Tomasso, Joseph R; Klaine, Stephen J

    2007-01-01

    Some toxicology research in which toxicant exposures are continual (pulsed) rather than continuous have been reported. A number of toxicity models have been developed for pulsed and continuous exposures. Most of these models were developed based on one- or two-compartment, first-order toxicokinetics and were calibrated with organic compounds. In the present study, the relationship between mortality (after 21 d) of Daphnia magna in response to pulsed and continuous exposures to Cu, Zn, and Se was used to develop a model that integrated the effects of single and multiple pulsed metal exposures based on first-order uptake and depuration kinetics. Mortality was a function of exposure concentration, duration, and recovery time between exposures. The model was successfully validated using an independent data set. It is applicable to risk assessment and, potentially, may be incorporated with other models (e.g., the biotic ligand model) to predict the toxicity of pulsed metal exposures under a range of environmental conditions. PMID:17269470

  20. Effect of stress at dosing on organophosphate and heavy metal toxicity

    International Nuclear Information System (INIS)

    This paper reviews recent studies assessing the effect of well-defined, severe, transient stress at dosing on two classical models of toxicity. These are the acute (anticholinesterase) toxicity seen following exposure to the organophosphate insecticide chlorpyrifos, and the nephrotoxicity elicited by the heavy metal depleted uranium, in rats. Stress was induced by periods of restraint and forced swimming in days to weeks preceding toxicant exposure. Forced swimming was far more stressful, as measured by marked, if transient, elevation of plasma corticosterone. This form of stress was administered immediately prior to administration of chlorpyrifos or depleted uranium. Chlorpyrifos (single 60 mg/kg subcutaneously) elicited marked inhibition of brain acetylcholinesterase 4-day post-dosing. Depleted uranium (single intramuscular doses of 0.1, 0.3 or 1.0 mg/kg uranium) elicited dose-dependent increase in kidney concentration of the metal, with associated injury to proximal tubular epithelium and increases in serum blood urea nitrogen and creatinine during the 30-day post-dosing period. Stress at dosing had no effect on these toxicologic endpoints

  1. The study of acute toxicity and antihypoxic activity of new metal complexes of iron

    Directory of Open Access Journals (Sweden)

    Shakhmardanova S.A.

    2015-03-01

    Full Text Available The Purpose: to determine the acute toxicity of new metal complexes of iron derived vinylimidazole and to reveal their antihypoxic activity in comparison with Acyzol and other known antihypoxic etomersol and hypoxen. Material and methods. Antihypoxic activity was studied in experiments on nonlinear white mice-males 4 models of acute hypoxia (hypobaric, hypoxia with hypercapnia, hemic, histotoxic. Rates of acute toxicity (LD16, LD LD were calculated graphically by the method of Miller and Tainter. Changes in oxidative metabolism in mice under the influence of the most active compounds were assessed by the values of oxygen consumption and rectal temperature. Results. The studied metal complexes of iron are small and moderately toxic. The connection under the code of Tetravim on the severity of antihypoxic effect (the increase in life expectancy male mice compared to control groups on 20-127% in the range of doses studied (5-250 mg/kg, i/p is superior to other derivatives of vinylimidazole known and antihypoxic: etomersol (25-100mg/kg, i/p and hypoxen (50-150 mg/kg, i/p. Conclusion. The obtained data on the pharmacological activity of Tetravim require further clarification of the mechanism of antihypoxic effect and clinical trials with the aim of putting it on the drugs market as a promising antihypoxic agent.

  2. Investigation of Hyporheic Microbial Biofilms as Indicators of Heavy Metal Toxicity in the Clark Fork Basin, Montana

    Science.gov (United States)

    Barnhart, E. P.; Hwang, C.; Bouskill, N.; Hornberger, M.; Fields, M. W.

    2015-12-01

    Water-saturated sediments that underlie a stream channel contain microbial biofilms that are often responsible for the majority of the metabolic activity in river and stream ecosystems. Metal contamination from mining effluent can modify the biofilm community structure, diversity, and activity. Developing a mechanistic understanding of the biofilm response to metal contamination could provide a useful bioindicator of metal toxicity due to the ease of standard biofilm sampling, environmental ubiquity of biofilms and the rapid response of biofilms to environmental perturbation and metal toxicity. Here we present data on the structure of the biofilm community (e.g., microbial population composition and diversity) and trace metal concentrations in water, bed sediment and biota (benthic insects) across 15 sites in the Clark Fork Basin. Sample sites were selected across a historically-monitored metal pollution gradient at shallow riffles with bed sediment predominantly composed of pebbles, cobbles, and sand. Bed-sediment samples (for biofilm analysis) were obtained from the top 20 centimeters of the hyporheic zone and sieved using sterile sieves to obtain homogeneous sediment samples with particle sizes ranging from 1.70 to 2.36 millimeters. Linear discriminant analysis and effect size statistical methods were used to integrate the metals concentration data (for water and benthic-insects samples) with the microbial community analysis to identify microbial biomarkers of metal toxicity. The development of rapid microbial biomarker tools could provide reproducible and quantitative insights into the effectiveness of remediation activities on metal toxicity and advances in the field of environmental biomonitoring.

  3. Where does the toxicity of metal oxide nanoparticles come from: The nanoparticles, the ions, or a combination of both?

    Science.gov (United States)

    Wang, Dali; Lin, Zhifen; Wang, Ting; Yao, Zhifeng; Qin, Mengnan; Zheng, Shourong; Lu, Wei

    2016-05-01

    The toxicity of metal oxide nanoparticles (NPs) has aroused great concern over the past few years. However, there still remains the question whether the toxicity of the metal oxide NPs originates from the released ions or the NPs themselves. In this study, the metal ion release of CuO, Fe2O3, ZnO, Co3O4, Cr2O3, and NiO NPs in aqueous media was investigated, and their contributions to the metal oxide NPs' inhibition on the bioluminescence of Photobacterium phosphoreum were studied. It was found that the ions release of the metal oxide NPs in aqueous media was complex, depending on both the dissolution and adsorption processes of the metal oxide NPs. The relationships between the metal oxide NPs' antibacterial effects and their released metal ions could be divided into three categories: (1) the ZnO NPs' antibacterial effect was due solely to the released Zn(2+); (2) the CuO NPs' antibacterial effect originated from both the released Cu(2+),and the CuO particles; and (3) the antibacterial effects of Fe2O3, Co3O4, Cr2O3, and NiO NPs were caused by the NPs themselves. Our findings suggest that the ions release and their contributions to the NPs' toxicity should be considered in the toxicity evaluations of the metal oxide NPs. PMID:26852208

  4. Toxicity of metal oxide nanoparticles in Escherichia coli correlates with conduction band and hydration energies.

    Science.gov (United States)

    Kaweeteerawat, Chitrada; Ivask, Angela; Liu, Rong; Zhang, Haiyuan; Chang, Chong Hyun; Low-Kam, Cecile; Fischer, Heidi; Ji, Zhaoxia; Pokhrel, Suman; Cohen, Yoram; Telesca, Donatello; Zink, Jeffrey; Mädler, Lutz; Holden, Patricia A; Nel, Andre; Godwin, Hilary

    2015-01-20

    Metal oxide nanoparticles (MOx NPs) are used for a host of applications, such as electronics, cosmetics, construction, and medicine, and as a result, the safety of these materials to humans and the environment is of considerable interest. A prior study of 24 MOx NPs in mammalian cells revealed that some of these materials show hazard potential. Here, we report the growth inhibitory effects of the same series of MOx NPs in the bacterium Escherichia coli and show that toxicity trends observed in E. coli parallel those seen previously in mammalian cells. Of the 24 materials studied, only ZnO, CuO, CoO, Mn2O3, Co3O4, Ni2O3, and Cr2O3 were found to exert significant growth inhibitory effects; these effects were found to relate to membrane damage and oxidative stress responses in minimal trophic media. A correlation of the toxicological data with physicochemical parameters of MOx NPs revealed that the probability of a MOx NP being toxic increases as the hydration enthalpy becomes less negative and as the conduction band energy approaches those of biological molecules. These observations are consistent with prior results observed in mammalian cells, revealing that mechanisms of toxicity of MOx NPs are consistent across two very different taxa. These results suggest that studying nanotoxicity in E. coli may help to predict toxicity patterns in higher organisms. PMID:25563693

  5. Toxic metals in children's toys and jewelry: Coupling bioaccessibility with risk assessment

    International Nuclear Information System (INIS)

    A total of 45 children's toys and jewelry were tested for total and bioaccessible metal concentrations. Total As, Cd, Sb, Cr, Ni, and Pb concentrations were 0.22–19, 0.01–139, 0.1–189, 0.06–846, 0.14–2894 and 0.08–860,000 mg kg−1. Metallic products had the highest concentrations, with 3–7 out of 13 samples exceeding the European Union safety limit for Cd, Pb, Cr, or Ni. However, assessment based on hazard index >1 and bioaccessible metal showed different trends. Under saliva mobilization or gastric ingestion, 11 out of 45 samples showed HI >1 for As, Cd, Sb, Cr, or Ni. Pb with the highest total concentration showed HI <1 for all samples while Ni showed the most hazard with HI up to 113. Our data suggest the importance of using bioaccessibility to evaluate health hazard of metals in children's toys and jewelry, and besides Pb and Cd, As, Ni, Cr, and Sb in children's products also deserve attention. - Highlights: • Contamination of toxic metals in children's toys and jewelry (TJ) were studied. • Metals including Pb, Cd, Cr, and Ni in some TJ exceeded the EU safety limits. • Hazard index of TJ was assessed based on bioaccessible metals via saliva mobilization and oral ingestion. • Hazard index was >> 1 for Ni, and unacceptable for As, Cd, Cr, and Sb in some TJ. - Assessment of health hazard of children's toys and jewelry based on bioaccessible metals suggested that besides Pb and Cd, As, Ni, Cr, and Sb in children's products deserve attention

  6. Phytoremediation of the toxic effluent generated during recovery of precious metals from polymetallic sea nodules.

    Science.gov (United States)

    Vaseem, Huma; Banerjee, T K

    2012-01-01

    Recovery of metals from the polymetallic sea nodules at the pilot plant at National Metallurgical Laboratory, Jamshedpur, India has generated a highly toxic effluent. This effluent contains several metals like Mn, Cu, Zn, Fe, Pb, Cr, and Cd that pollute the neighboring water bodies when discharged. Hence detoxification of this effluent was practiced using two plants: Lemna minor and Azolla pinnata for 7 days. During investigation A. pinnata removed 96% of Mn, 97% of Cu, 98% of Zn, 70% of Fe, 96% of Pb, 93% of Cr, 78% of Cd, and was comparatively more effective than L. minor which removed 94% of Mn, 86% of Cu, 62% of Zn, 74% of Fe, 84% of Pb, 63% of Cr, 78% of Cd. During the 7 days of experiment chlorophyll content decreased by 51% and 59% in A. pinnata and L. minor respectively. Based on our findings we can suggest that these two plants have wide range of metal retention potentialities hence can be of routine use for purification of toxic effluents. PMID:22567724

  7. Heavy-metal toxicity phenomena in laboratory-scale ANFLOW bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, A.L.

    1982-04-01

    An energy-conserving wastewater treatment system was developed based on an anaerobic, upflow (ANFLOW) bioreactor. Since many applications of the ANFLOW process could involve the treatment of wastewaters containing heavy metals, the potentially toxic effects of these metals on the biological processes occurring in ANFLOW columns (primarily acetogenesis and methanogenesis) were investigated. Both step and pulse inputs of zinc ranging from 100 to 1000 mg/L were added to synthetic wastewaters being treated in ANFLOW columns with 0.057-m/sup 3/ volumes. Column responses were used to develop descriptive models for toxicity phenomena in such systems. It was found that an inhibition function could be defined and used to modify a model based on plugflow with axial dispersion and first-order kinetics for soluble substrate removal. The inhibitory effects of zinc on soluble substrate removal were found to be predominantly associated with its sorption by biosolids. Sorption initially occurred in the lower regions of the column, but was gradually observed in higher regions as the sorption capacity of the lower regions was exhausted. Sorption phenomena could be described with the Freundlich equation. Sorption processes were accompanied by shifts of biological processes to regions higher in the columns. A regenerative process was observed when feeding of wastewaters without zinc was resumed. It was postulated that regeneration could be based on sloughing of layers of biofilms, or other biosolids involved in zinc sorption, followed by continued growth of lower layers of biofilms not involved in heavy-metal sorption.

  8. Determination of toxic heavy metals and speciation of arsenic in seaweeds from South Korea.

    Science.gov (United States)

    Khan, Naeem; Ryu, Keun Yeoung; Choi, Ji Yeon; Nho, Eun Yeong; Habte, Girum; Choi, Hoon; Kim, Mee Hye; Park, Kyung Su; Kim, Kyong Su

    2015-02-15

    This study aimed at determining the levels of toxic heavy metals including As, Pb, Cd, Al, Hg and As species, such as, As-III, As-V, MMA, DMA, AsB, and AsC in various edible species of seaweeds from South Korea. ICP-MS was used for determination of As, Pb and Cd, ICP-OES was used for Al, DMA was used for Hg, and LC-ICP-MS was used for As speciation. The analytical methods were validated by linearity, detection limits, precision, accuracy and recovery experiments, obtaining satisfactory results in all cases. From the results toxic heavy metals were found in the decreasing order of: Al>As>Pb-Cd>Hg. Generally concentrations of all analysed heavy metals and both organic and inorganic species of As were very low compared to PTWIs specified by JECFA and EC. Their contribution to the overall intake by the subject seafoods was found very low and thus would not pose any threat to consumers. PMID:25236252

  9. In vivo monitoring of toxic metals: assessment of neutron activation and x-ray fluorescence techniques

    International Nuclear Information System (INIS)

    To date, cadmium, lead, aluminum, and mercury have been measured in vivo in humans. The possibilities of monitoring other toxic metals have also been demonstrated, but no human studies have been performed. Neutron activation analysis appears to be most suitable for Cd and Al measurements, while x-ray fluorescence is ideally suited for measurement of lead in superficial bone. Filtered neutron beams and polarized x-ray sources are being developed which will improve in vivo detection limits. Even so, several of the current facilities are already suitable for use in epidemiological studies of selected populations with suspected long-term low-level ''environmental'' exposures. Evaluation and diagnosis of patients presenting with general clinical symptoms attributable to possible toxic metal exposure may be assisted by in vivo examination. Continued in vivo monitoring of industrial workers, especially follow-up measurements, will provide the first direct assessment of changes in body burden and a direct measure of the biological life-times of these metals in humans. 50 refs., 4 figs., 2 tabs

  10. Application of ecological risk indicators for the assessment of Greek surficial sediments contaminated by toxic metals.

    Science.gov (United States)

    Hahladakis, John Ν; Vasilaki, Georgia; Smaragdaki, Eleftheria; Gidarakos, Evangelos

    2016-05-01

    Τhe present research investigates the partitioning of six selected toxic metals (Ni, Cr, Pb, Zn, Cu, and As) in eight sediment samples; half of them were collected from Elefsis Gulf, and the other half were taken from Koumoundourou Lake, Athens, Greece. Each one of them was treated by applying Tessier's five-step sequential extraction procedure. Regarding gulf sediments, the results indicated that Cu exhibits a strong affinity to the organic matter with percentages ranging from 65 to 78 %. Considerable amount of Zn (32-40 %) is bound to the Fe-Mn fraction and the non-residual fraction, while Cr and Ni are bound to the organic fraction, an observation that suits all toxic metals examined. Regarding lake sediments, Pb is the predominant metal bound to Fe-Mn (48-51 %). It is also noteworthy that the percentage of Zn bound to carbonated fraction (5-15 %), indicating biological availability. In conclusion, the application of several ecological risk indicators demonstrated that Elefsis Gulf sediments correspond to a moderate pollution level, with Pb and Ni being less bioavailable than in the lake's samples, in contrast to Zn which is more bioavailable. Finally, Koumoundourou Lakes' basin is characterized of "low risk." PMID:27052348

  11. Potentially Toxic Metal and Metalloid Fractionation Contamination in Sediments of Daya Bay, South China Sea

    Directory of Open Access Journals (Sweden)

    L. L. Cao

    2015-05-01

    Full Text Available The metal profiles in sediments of the Daya Bay (DYB in China were established using sequential extraction protocols proposed by the European Community Bureau of Reference (BCR. The surface sediment samples from 23 representative stations were collected in 2011 and were analysed to evaluate the mobility and bioavailability of a suite of potentially toxic metals (Cr, Cu, Ni, Zn, Pb and Cd and metalloid (As. The obtained ranking order of migration and transformation, and the degree of pollution was Pb > Cd > Cu > Zn > Ni > Cr > As. Among these elements, Pb is considered to pose a serious threat to human health and ecological environment due to its significant percentage in non-residual form. The ratios of secondary and primary phases showed that studied sediments are moderately to heavily polluted with Cu and Zn, and Cd and Pb respectively. The levels of association between the variables (metal-metalloid at each step of sequential extractions were evaluated with multivariate statistical analysis, including correlation analysis and principal components analysis. With these analyses, the possible sources of potential pollution were deduced. The correlation analysis revealed that Total Organic Carbon content is the most important influencing factor affecting the distribution of potentially toxic elements in Daya Bay. The principal components analysis (PCA suggested that the studied elements in DYB area originate primarily from natural weathering and secondly from industrial wastewater and aquaculture waste water.

  12. Speciation Methods Used to Assess Potential Health Effects of Toxic Metals in Environmental Materials

    Science.gov (United States)

    Wolf, Ruth E.; Morman, Suzette A.; Plumlee, Geoffrey S.

    2008-01-01

    Assessing potential exposures to toxic metals or metalloids such as arsenic and chromium in environmental materials is important in protecting public health. The chemical form of an element in, or released from, a material is also important, since some forms, such as Cr(VI), are more toxic than others, for example, Cr(III). We have used a variety of procedures to assess potential exposures to hexavalent chromium in ash and burned soils from October 2007 southern California wildfires. Synthetic lung-fluid and de-ionized water extractions simulate release in the lungs and potential environmental releases due to rainfall. Extracts were analyzed for specific chromium and arsenic species using HPLC-ICP-MS methodology. Results indicate that the highly oxidizing environment in wildfires promotes some chromium conversion to Cr(VI), and that the caustic alkalinity of ash enhances Cr(VI) release and stability in lung fluids and rainfall.

  13. Inorganic materials as ameliorants for soil remediation of metal toxicity to wild mustard (Sinapis arvensis L.).

    Science.gov (United States)

    Ribeiro Filho, Mateus Rosas; Siqueira, José Oswaldo; Vangronsveld, Jaco; Soares, Cláudio Roberto Fonsêca Sousa; Curi, Nilton

    2011-01-01

    The ameliorating effects of different inorganic materials were investigated on a soil originating from a zinc smelter dumping site contaminated by toxic metals. Wild mustard (Sinapis arvensis L.) was used as a test plant. The soil was amended with different doses of mining sludge, Perferric Red Latosol (LVj), steel shots, cyclonic ash, silifertil, and superphosphate. The most effective amendments improved plant growth with 45% and reduced metal uptake by over 70% in comparison to untreated soil. Reductions in availability as estimated by BaCl2-extractable metals reached up to 90% for Zn and 65% for Cd as compared to unamended soil. These reductions were associated with lower shoot and root metal contents. Shoot Zn content was reduced from 1,369 microg g(-1) in plants grown on untreated soil to 377 microg g(-1) when grown on cyclonic ash amended soil while Cd decreased from 267 to 44 microg g(-1) in steel shots amended soil. Superphosphate addition had no ameliorating effect. On the contrary, it increased BaCl2-extractable amounts of Zn. Considering all parameters we determined, steel shots, cyclonic ash and silifertil are the most promising for remediating metal contaminated soil in the tropics. Further studies evaluating impacts, cost-effectiveness and durability of effects will be conducted. PMID:21598779

  14. Dispersion and toxicity of metals from abandoned gold mine tailings at Goldenville, Nova Scotia, Canada

    International Nuclear Information System (INIS)

    As its name indicates, Goldenville was a famous gold mining area in Nova Scotia where large quantities of mercury were used in the gold recovery process. It is estimated that the 3 million tons of tailings left from the mining activities which lasted from 1860 to 1945 contain 470 kg of Cd, 37-300 kg of Pb, 6800 kg of Hg, 20-700 kg of As and 2600 kg of Tl. Analysis of metal contents of stream water, stream and lake sediments, tailings, and vegetation show that the tailings have been distributed over time across the stream basin to form a tailing field of approximately 2 km2. There is a continuous release of As, Hg, Pb, Tl and other metals from the tailing field, resulting in contamination of ecosystems downstream including the Gagogan Harbor of the Atlantic Ocean. Stream water and sediments of Lake Gagogan located downstream from the mine were found toxic to the benthic community. A loss of fish habitat was observed. Although the mines were closed over 50 years ago, sedimentary records of metal loadings into Lake Gagogan show that the release of metals from the tailings has not slowed down. Analysis of metal tolerant species in the area suggests that horsetails (Equisetum rubiaceae and E. sylvaticum) can be used in phytoremediation of sites contaminated with arsenic and mercury. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  15. Heavy metal accumulation and toxicity in smoothhound (Mustelus mustelus) shark from Langebaan Lagoon, South Africa.

    Science.gov (United States)

    Bosch, Adina C; O'Neill, Bernadette; Sigge, Gunnar O; Kerwath, Sven E; Hoffman, Louwrens C

    2016-01-01

    Together with several health benefits, fish meat could introduce toxins to consumers in the form of heavy metal contaminants. High levels of mercury (Hg), especially, are frequently detected in certain predatory fish species. Mustelus mustelus fillets were analysed for 16 metals and three individual Hg species (inorganic Hg, ehtylmercury, methylmercury) with inductively coupled plasma mass spectrometry (ICP-MS) and HPLC-ICP-MS respectively. Eleven of the 30 sharks had total Hg levels above the maximum allowable limit with toxic methylmercury found as the dominant mercury species with a strong correlation (r = 0.97; p < 0.001) to total mercury concentrations. Limited correlations between metals and shark size parameters were observed; therefore metal accumulation in M. mustelus is mostly independent of size/age. Average values for arsenic (28.31 ± 18.79 mg/kg) exceed regulatory maximum limits and Hg (0.96 ± 0.69 mg/kg) is close to the maximum limit with all other metals well below maximum limits. PMID:26213051

  16. Dispersion and toxicity of metals from abandoned gold mine tailings at Goldenville, Nova Scotia, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Wong, H.K.T. [National Water Research Institute, P.O. Box 5050, Burlington (Canada); Gauthier, A. [Environmental Protection Branch, Environment Canada, Dartmouth, Nova Scotia (Canada); Nriagu, J.O. [Department of Environmental and Industrial Health, School of Public Health, University of Michigan, Ann Arbor, MI (United States)

    1999-03-22

    As its name indicates, Goldenville was a famous gold mining area in Nova Scotia where large quantities of mercury were used in the gold recovery process. It is estimated that the 3 million tons of tailings left from the mining activities which lasted from 1860 to 1945 contain 470 kg of Cd, 37-300 kg of Pb, 6800 kg of Hg, 20-700 kg of As and 2600 kg of Tl. Analysis of metal contents of stream water, stream and lake sediments, tailings, and vegetation show that the tailings have been distributed over time across the stream basin to form a tailing field of approximately 2 km{sup 2}. There is a continuous release of As, Hg, Pb, Tl and other metals from the tailing field, resulting in contamination of ecosystems downstream including the Gagogan Harbor of the Atlantic Ocean. Stream water and sediments of Lake Gagogan located downstream from the mine were found toxic to the benthic community. A loss of fish habitat was observed. Although the mines were closed over 50 years ago, sedimentary records of metal loadings into Lake Gagogan show that the release of metals from the tailings has not slowed down. Analysis of metal tolerant species in the area suggests that horsetails (Equisetum rubiaceae and E. sylvaticum) can be used in phytoremediation of sites contaminated with arsenic and mercury. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  17. Optical nanosphere sensor based on shell-by-shell fabrication for removal of toxic metals from human blood.

    Science.gov (United States)

    El-Safty, S A; Abdellatef, S; Ismael, M; Shahat, A

    2013-06-01

    Because toxic heavy metals tend to bioaccumulate, they represent a substantial human health hazard. Various methods are used to identify and quantify toxic metals in biological tissues and environment fluids, but a simple, rapid, and inexpensive system has yet to be developed. To reduce the necessity for instrument-dependent analysis, we developed a single, pH-dependent, nanosphere (NS) sensor for naked-eye detection and removal of toxic metal ions from drinking water and physiological systems (i.e., blood). The design platform for the optical NS sensor is composed of double mesoporous core-shell silica NSs fabricated by one-pot, template-guided synthesis with anionic surfactant. The dense shell-by-shell NS construction generated a unique hierarchical NS sensor with a hollow cage interior to enable accessibility for continuous monitoring of several different toxic metal ions and efficient multi-ion sensing and removal capabilities with respect to reversibility, longevity, selectivity, and signal stability. Here, we examined the application of the NS sensor for the removal of toxic metals (e.g., lead ions from a physiological system, such as human blood). The findings show that this sensor design has potential for the rapid screening of blood lead levels so that the effects of lead toxicity can be avoided. PMID:23307510

  18. Heavy and toxic metals in the waste from some industrial facilities in the town of Skopje, Republic of Macedonia

    OpenAIRE

    Lepitkova, Sonja; BOEV, BLAZO

    1999-01-01

    This paper presents the results of several months' investigations carried out on the heavy metals and toxic metals in waste waters from the town of Skopje that flow into the River Vardar. The results discovered increased amounts of arsenic, manganese and silver in the waste waters that come from the activities in industrial facilities located in and around the town

  19. Removal of uranium, cesium, strontium, toxic metals and radioactive cesium by a photosynthetic bacteria

    International Nuclear Information System (INIS)

    Using immobilized Rhodobacter Sphaeroides SSI on porous silicate ceramics the authors have demonstrated the removal of about 100, 83, and 58% of radioactivity of uranium, strontium, and cobalt and also almost 100% of such toxic metals as mercury, chromium, and arsenic after two or three days treatment. Furthermore, the water sampling from the swimming pools and also the soils from the agricultural fields near Fukushima Daiichi Nuclear Power Plant were found to be decontaminated by using immobilized SSI and/or combined with Lactobacillus casei immobilized on porous glasses with satisfactory results which show the present method might be practical decontamination. (S. Ohno)

  20. Bioaccumulation of toxic metals by fish in a semi enclosed tropical ecosystem

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, M.; Jayalakshmy, K.V.; Balachandran, K.K.; Joseph, T.

    Forensics, 7:197–206, 2006 Copyright C© Taylor & Francis Group, LLC ISSN: 1527–5922 print / 1527–5930 online DOI: 10.1080/15275920600840438 Bioaccumulation of Toxic Metals by Fish in a Semi-Enclosed Tropical Ecosystem Maheswari Nair, K. V. Jayalakshmy, K. K... coefficient of linear correlation, r (Sokal and Rholf, 1981). The 17 fish species are clustered using Bray Curtis similarity index (Bray and Curtis, 1957) and den- drograms are drawn by applying a group linkage clustering tech- nique using the PRIMER v5 data...

  1. Migration of Toxic Metals from Ceramic Food Packaging Materials into Acid Food Simulants

    OpenAIRE

    Zhanhua Dong; Lixin Lu; Zhigang Liu; Yali Tang; Jun Wang

    2014-01-01

    Long-term extraction experiments were carried out on glazed tile specimens with 4 and 10% (v/v) acetic acid, 1% (w/v) citric acid, and 1% (v/v) lactic acid solution in three temperature conditions (20, 40, and 60°C) to investigate the effect of temperature and pH value on extraction of lead, cobalt, nickel, and zinc from ceramic food packaging materials and to study the extraction kinetics of toxic metals. Results showed that except at 60°C the amount of extraction of lead, cobalt, nickel, an...

  2. Down-Regulation of a Manganese Transporter in the Face of Metal Toxicity

    OpenAIRE

    Jensen, Laran T.; Carroll, Mark C.; Hall, Matthew D.; Harvey, Christopher J.; Beese, Sara E.; Culotta, Valeria C.

    2009-01-01

    The yeast Smf1p Nramp manganese transporter is posttranslationally regulated by environmental manganese. Smf1p is stabilized at the cell surface with manganese starvation, but is largely degraded in the vacuole with physiological manganese through a mechanism involving the Rsp5p adaptor complex Bsd2p/Tre1p/Tre2p. We now describe an additional level of Smf1p regulation that occurs with toxicity from manganese, but not other essential metals. This regulation is largely Smf1p-specific. As with p...

  3. Toxicity of binary mixtures of metal oxide nanoparticles to Nitrosomonas europaea.

    Science.gov (United States)

    Yu, Ran; Wu, Junkang; Liu, Meiting; Zhu, Guangcan; Chen, Lianghui; Chang, Yan; Lu, Huijie

    2016-06-01

    Although the widely used metal oxide nanoparticles (NPs) titanium dioxide NPs (n-TiO2), cerium dioxide NPs (n-CeO2), and zinc oxide NPs (n-ZnO) have been well known for their potential cytotoxicities to environmental organisms, their combined effects have seldom been investigated. In this study, the short-term binary effect of n-CeO2 and n-TiO2 or n-ZnO on a model ammonia oxidizing bacterium, Nitrosomonas europaea were evaluated based on the examinations of cells' physiological, metabolic, and transcriptional responses. The addition of n-TiO2 mitigated the negative effect of more toxic n-CeO2 and the binary toxicity (antagonistic toxicity) of n-TiO2 and n-CeO2 was generally lower than the single NPs induced one. While the n-CeO2/n-ZnO mixture exerted higher cytotoxicity (synergistic cytotoxicity) than that from single NPs. The increased addition of the less toxic n-CeO2 exaggerated the binary toxicity of n-CeO2/n-ZnO mixture although the solubility of n-ZnO was not significantly affected, which excluded the contribution of the dissolved Zn ions to the enhancement of the combined cytotoxicity. The cell membrane disturbances and NP internalizations were detected for all the NP impacted cultures and the electrostatic interactions among the two distinct NPs and the cells were expected to play a key role in mediating their direct contacts and the eventual binary nanotoxicity to the cells. PMID:27016814

  4. INAA of toxic heavy metals in solid wastes from Indian cities

    International Nuclear Information System (INIS)

    Solid wastes and sewage sludges in metropolitan cities are potential health hazards due to toxic heavy metal pollutants. Sewage sludges from six Indian cities viz., Ahmedabad, Bikaner, Bombay, Calcutta, Jaipur, Kanpur and solid wastes from six different disposal sites of the capital city of Delhi have been analyzed for 26 elements (As, Au, Ba, Br, Co, Cr, Cs, Cu, Eu, Fe, Hg, Hf, K, La, Mg, Mn, Mo, Na, P, Rb, Sb, Sc, Se, Sr, Th and Zn) by employing instrumental neutron activation analysis (INAA). Sewage sludges from Bombay after different treatments (settled, digested, aerobic, anaerobic) along with several environmental SRMs were also analyzed. An attempt has been made to attribute the pollutant sources to the degree of urbanisation and industrialization of the city. Role of treatment processes in the removal/retention of heavy metals is discussed. (author)

  5. Transport of toxic metals through the major river systems of Bangladesh

    International Nuclear Information System (INIS)

    Bangladesh having an area of about 144000 sq. km with a population of more than 120 millions is situated in the northeastern part of the south Asia subcontinent and a vast area to the south in the bay of Bengal. The largest delta in the world has a larger catchments area of about 1554000 sq. km spread over five countries namely Bhutan, Nepal, China, India and Bangladesh. Environmental pollution usually refers to biological, chemical and physical materials introduced largely as a result of human activities. Water is one of the main source of the environmental pollution and the contamination of water by the metal ions at the trace levels is generally occurred through natural processes or anthropogenic sources. Buriganga, Sitalaksma, Bramhaputra and Jamuna were selected for the present study. The toxic metal ions concentration in water samples of various region of different rivers were determined by ASS and GFAAS. The highest amount of As was found in the Karnafully River at KAFCOO (34.6 +-1.2 mug/L) in the dry season and lowest in the buriganga river at Badamtoli (5.3 +-0.1 mu g/L). the highest amount of Pb was found in the dry season at kalurghat (13. 0.05 mu g/L) in Karnafully River. The highest amount of Cd was found in the river of Karnafully at KAFCOO (27. 0.4 mu g/L) in dry season. These observations demand the need of regular monitoring of toxic metal ions concentration in different rivers especially Buriganga, Sitalaksma and Karnafully. The concentration of As, Pb and Cd determined in this study is below the recommended values of WHO (World Health Organization) and EQS (Environmental Quality Standards of Bangladesh). The methods that adopted to investigate these metals were in good agreement with standard solution (Merck, Germany, code no: J/4546/05), where +- .0% deviation was found. (author)

  6. The use of biogas plant fermentation residue for the stabilisation of toxic metals in agricultural soils

    Science.gov (United States)

    Geršl, Milan; Šotnar, Martin; Mareček, Jan; Vítěz, Tomáš; Koutný, Tomáš; Kleinová, Jana

    2015-04-01

    Our department has been paying attention to different methods of soil decontamination, including the in situ stabilisation. Possible reagents to control the toxic metals mobility in soils include a fermentation residue (FR) from a biogas plant. Referred to as digestate, it is a product of anaerobic decomposition taking place in such facilities. The fermentation residue is applied to soils as a fertiliser. A new way of its use is the in situ stabilisation of toxic metals in soils. Testing the stabilisation of toxic metals made use of real soil samples sourced from five agriculturally used areas of the Czech Republic with 3 soil samples taken from sites contaminated with Cu, Pb and Zn and 2 samples collected at sites of natural occurrence of Cu, Pb and Zn ores. All the samples were analysed using the sequential extraction procedure (BCR) (determine the type of Cu, Pb and Zn bonds). Stabilisation of toxic metals was tested in five soil samples by adding reagents as follows: dolomite, slaked lime, goethite, compost and fermentation residue. A single reagent was added at three different concentrations. In the wet state with the added reagents, the samples were left for seven days, shaken twice per day. After seven days, metal extraction was carried out: samples of 10 g soil were shaken for 2 h in a solution of 0.1M NH4NO3 at a 1:2.5 (g.ml-1), centrifuged for 15 min at 5,000 rpm and then filtered through PTFE 0.45 μm mesh filters. The extracts were analysed by ICP-OES. Copper The best reduction of Cu concentration in the extract was obtained at each of the tested sites by adding dolomite (10 g soil + 0.3 g dolomite). The concentration of Cu in the leachate decreased to 2.1-18.4% compare with the leachate without addition. Similar results were also shown for the addition of fermentation residue (10 g soil + 1 g FR). The Cu concentration in the leachate decreased to 16.7-26.8% compared with the leachate without addition. Lead The best results were achieved by adding

  7. Development of Comparative Toxicity Potentials of 14 cationic metals in freshwater.

    Science.gov (United States)

    Dong, Yan; Gandhi, Nilima; Hauschild, Michael Z

    2014-10-01

    Site-dependent and site-generic Comparative Toxicity Potentials (CTPs) (also known as Characterization Factors (CFs)) were calculated for 14 cationic metals (Al(III), Ba, Be, Cd, Co, Cr(III), Cs, Cu(II), Fe(II), Fe(III), Mn(II), Ni, Pb, Sr and Zn), to be applied in Life Cycle Impact Assessment. CTPs were calculated for 7 EU-archetypes, taking bioavailability and speciation pattern into account. The resulting site-dependent CTPs showed up to 2.4-6.5 orders of magnitude variation across archetypes for those metals that form stable hydroxyl compounds in slightly alkaline waters (Al(III), Be, Cr(III), Cu(II) and Fe(III)), emphasizing the importance of using site-dependent CTPs for these metals where possible. For the other metals, CTPs stayed within around 0.9 orders of magnitude, making spatial differentiation less important. In acidic waters (pHarchetype CTPs was recommended as site-generic CTP for use in LCA studies, where receiving location is unclear. Compared to previous studies by Gandhi et al. (2010, 2011a), new site-dependent CTPs were similar or slightly higher for Cd, Co, Ni, Pb and Zn, but 1-2 orders of magnitude higher for Cu. Compared to the default site-generic CTPs in the frequently used characterization models USES-LCA and USEtox, new site-generic CTPs were mostly higher or similar, within up to ∼2 orders of magnitude difference. PMID:25048884

  8. Development of Comparative Toxicity Potentials of 14 cationic metals in freshwater

    DEFF Research Database (Denmark)

    Dong, Yan; Gandhi, Nilima; Hauschild, Michael Zwicky

    2014-01-01

    . CTPs were calculated for 7 EUarchetypes, taking bioavailability and speciation pattern into account. The resulting site-dependent CTPs showed up to 2.4–6.5 orders of magnitude variation across archetypes for those metals that form stable hydroxyl compounds in slightly alkaline waters (Al(III), Be, Cr......Site-dependent and site-generic Comparative Toxicity Potentials (CTPs) (also known as Characterization Factors (CFs)) were calculated for 14 cationic metals (Al(III), Ba, Be, Cd, Co, Cr(III), Cs, Cu(II), Fe(II), Fe(III), Mn(II), Ni, Pb, Sr and Zn), to be applied in Life Cycle Impact Assessment......(III), Cu(II) and Fe(III)), emphasizing the importance of using site-dependent CTPs for these metals where possible. For the other metals, CTPs stayed within around 0.9 orders of magnitude, making spatial differentiation less important. In acidic waters (pH < 6.4), Al(III) and Cu(II) had the highest CTPs...

  9. Metal toxicity and biodiversity in serpentine soils: application of bioassay tests and microarthropod index.

    Science.gov (United States)

    Visioli, Giovanna; Menta, Cristina; Gardi, Ciro; Conti, Federica Delia

    2013-01-01

    Eco-toxicological or bioassay tests have been intensively discussed as tools for the evaluation of soil quality. Tests using soil organisms, including microarthropods and plants, allow direct estimates to be made of important soil characteristics and functions. In this study we compared the results obtained by two in vitro standard bioassays following ISO or OECD guidelines: (i) the short term-chronic phytotoxicity germination and root elongation test using three different plant species Cucumis sativus L. (Cucurbitaceae), Lepidium sativum L. (Brassicaceae), and Medicago sativa L. (Fabaceae) and (ii) the inhibition of reproduction of Folsomia candida (Collembola) by soil pollutants to investigate the toxicity of a serpentine soil present in the Italian Apennines, rich in heavy metals such as Ni, Cr, and Co. In addition, microarthropod communities were characterised to evaluate the effects of metal contents on the soil fauna in natural conditions. Abundances, Acari/Collembola ratio, biodiversity indices and the QBS-ar index were calculated. Our results demonstrate that the two in vitro tests distinguish differences correlated with metal and organic matter contents in four sub-sites within the serpentinite. Soil fauna characterisation, not previously performed on serpentine soils, revealed differences in the most vulnerable and adapted groups of microarthropods to soil among the four sub-sites: the microarthropod community was found to be rich in term of biodiversity in the sub-site characterised by a lower metal content and a higher organic matter content and vegetation. PMID:23107056

  10. Engineering Metal Ion Coordination to Regulate Amyloid Fibril Assembly And Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Dong, J.; Canfield, J.M.; Mehta, A.K.; Shokes, J.E.; Tian, B.; Childers, W.S.; Simmons, J.A.; Mao, Z.; Scott, R.A.; Warncke, K.; Lynn, D.G.

    2009-06-02

    Protein and peptide assembly into amyloid has been implicated in functions that range from beneficial epigenetic controls to pathological etiologies. However, the exact structures of the assemblies that regulate biological activity remain poorly defined. We have previously used Zn{sup 2+} to modulate the assembly kinetics and morphology of congeners of the amyloid {beta} peptide (A{beta}) associated with Alzheimer's disease. We now reveal a correlation among A{beta}-Cu{sup 2+} coordination, peptide self-assembly, and neuronal viability. By using the central segment of A{beta}, HHQKLVFFA or A{beta}(13-21), which contains residues H13 and H14 implicated in A{beta}-metal ion binding, we show that Cu{sup 2+} forms complexes with A{beta}(13-21) and its K16A mutant and that the complexes, which do not self-assemble into fibrils, have structures similar to those found for the human prion protein, PrP. N-terminal acetylation and H14A substitution, Ac-A{beta}(13-21)H14A, alters metal coordination, allowing Cu{sup 2+} to accelerate assembly into neurotoxic fibrils. These results establish that the N-terminal region of A{beta} can access different metal-ion-coordination environments and that different complexes can lead to profound changes in A{beta} self-assembly kinetics, morphology, and toxicity. Related metal-ion coordination may be critical to the etiology of other neurodegenerative diseases.

  11. Metal mixture toxicity to aquatic biota in laboratory experiments: Application of the WHAM-F{sub TOX} model

    Energy Technology Data Exchange (ETDEWEB)

    Tipping, E., E-mail: et@ceh.ac.uk; Lofts, S.

    2013-10-15

    Highlights: •Metal accumulation by living organisms is successfully simulated with WHAM. •Modelled organism-bound metal provides a measure of toxic exposure. •The toxic potency of individual bound metals is quantified by fitting toxicity data. •Eleven laboratory mixture toxicity data sets were parameterised. •Relatively little variability amongst individual test organisms is indicated. -- Abstract: The WHAM-F{sub TOX} model describes the combined toxic effects of protons and metal cations towards aquatic organisms through the toxicity function (F{sub TOX}), a linear combination of the products of organism-bound cation and a toxic potency coefficient (α{sub i}) for each cation. Organism-bound, metabolically-active, cation is quantified by the proxy variable, amount bound by humic acid (HA), as predicted by the WHAM chemical speciation model. We compared published measured accumulations of metals by living organisms (bacteria, algae, invertebrates) in different solutions, with WHAM predictions of metal binding to humic acid in the same solutions. After adjustment for differences in binding site density, the predictions were in reasonable line with observations (for logarithmic variables, r{sup 2} = 0.89, root mean squared deviation = 0.44), supporting the use of HA binding as a proxy. Calculated loadings of H{sup +}, Al, Cu, Zn, Cd, Pb and UO{sub 2} were used to fit observed toxic effects in 11 published mixture toxicity experiments involving bacteria, macrophytes, invertebrates and fish. Overall, WHAM-F{sub TOX} gave slightly better fits than a conventional additive model based on solution concentrations. From the derived values of α{sub i}, the toxicity of bound cations can tentatively be ranked in the order: H < Al < (Zn–Cu–Pb–UO{sub 2}) < Cd. The WHAM-F{sub TOX} analysis indicates much narrower ranges of differences amongst individual organisms in metal toxicity tests than was previously thought. The model potentially provides a means to

  12. Extrapolating between toxicity endpoints of metal oxide nanoparticles: Predicting toxicity to Escherichia coli and human keratinocyte cell line (HaCaT) with Nano-QTTR.

    Science.gov (United States)

    Kar, Supratik; Gajewicz, Agnieszka; Roy, Kunal; Leszczynski, Jerzy; Puzyn, Tomasz

    2016-04-01

    Synthesis of novel nanoparticles should always be accompanied by a comprehensive assessment of risk to human health and to ecosystem. Application of in silico models is encouraged by regulatory authorities to fill the data gaps related to the properties of nanoparticles affecting the environment and human health. Interspecies toxicity correlations provide a tool for estimation of contaminant's sensitivity with known levels of uncertainty for a diverse pool of species. We propose here first interspecies cytotoxicity correlation models between Escherichia coli (prokaryotic system) and human keratinocyte cell line (HaCaT) (eukaryotic system) to assess the discriminatory features for cytotoxicity of metal oxide nanoparticles. The nano-QTTR models can be employed for extrapolating cytotoxicity to E. coli and human keratinocyte cell line (HaCaT) for metal nanoparticles when the data for the other species are available. Informative illustrations of the contributing mechanisms of toxic action of the metal oxide nanoparticles to the HaCaT cell line as well as to the E. coli are identified from the developed nano quantitative toxicity-toxicity relationship (nano-QTTR) models. PMID:26773833

  13. Toxicity and bioavailability of metals in the Missouri River adjacent to a lead refinery

    Science.gov (United States)

    Chapman, Duane C.; Allert, Ann L.; Fairchild, James F.; May, Thomas W.; Schmitt, Christopher J.; Callahan, Edward V.

    2001-01-01

    This study is an evaluation of the potential environmental impacts of contaminated groundwater from the ASARCO metals refining facility adjacent to the Missouri River in Omaha, Nebraska. Surface waters, sediments, and sediment pore waters were collected from the Burt-Izard drain, which transects the facility, and from the Missouri River adjacent to the facility. Groundwater was also collected from the facility. Waters and sediments were analyzed for inorganic contaminants, and the toxicity of the waters was evaluated with the Ceriodaphnia dubia 7-day test. Concentrations of several elemental contaminants were highly elevated in the groundwater, but not in river sediment pore waters. Lead concentrations were moderately elevated in whole sediment at one site, but lead concentrations in pore waters were low due to apparent sequestration by acid-volatile sulfides. The groundwater sample was highly toxic to C. dubia, causing 100% mortality. Even at the lowest groundwater concentration tested (6.25%) C. dubia survival was reduced; however, at that concentration, reproduction was not significantly different from upstream porewater reference samples. Sediment pore waters were not toxic, except reproduction in pore water collected from one downstream site was somewhat reduced. The decrease in reproduction could not be attributed to measured elemental contaminants.

  14. High antioxidative potential and low toxic effects of selenosemicarbazone metal complexes

    Directory of Open Access Journals (Sweden)

    Dekanski Dragana

    2013-01-01

    Full Text Available Novel metal-based compounds with therapeutic potential became the subject of intense investigation in inorganic chemistry and biomedical science. Recently, strong dose-dependent cytotoxic activity against several human cancer cell lines of selenosemicarbazone metal complexes was demonstrated. The aim of the present study was to investigate in vitro antioxidative potential of Ni(II, Cd(II and Zn(II selenosemicarbazone complexes. All three investigated complexes exhibited high ABTS radical scavenging capacity, comparable with ascorbic acid. In the acute toxicity study, administration of the compounds was performed orally to the mice at the single doses and they were observed for clinical signs, body weight effects, and mortality for 14 days after which they were sacrificed for gross organ necropsy. Body weight did not vary after administration, and the autoptic analysis failed to show appreciable macroscopic alterations of internal organs. Generally, the compounds exhibited low toxic effects as required for further in vivo therapeutic studies. [Projekat Ministarstva nauke Republike Srbije, br. 451-03-2372-IP type 1/79: Antioxidants based on selenium complex compounds - research and development

  15. Architecture of optical sensor for recognition of multiple toxic metal ions from water.

    Science.gov (United States)

    Shenashen, M A; El-Safty, S A; Elshehy, E A

    2013-09-15

    Here, we designed novel optical sensor based on the wormhole hexagonal mesoporous core/multi-shell silica nanoparticles that enabled the selective recognition and removal of these extremely toxic metals from drinking water. The surface-coating process of a mesoporous core/double-shell silica platforms by several consequence decorations using a cationic surfactant with double alkyl tails (CS-DAT) and then a synthesized dicarboxylate 1,5-diphenyl-3-thiocarbazone (III) signaling probe enabled us to create a unique hierarchical multi-shell sensor. In this design, the high loading capacity and wrapping of the CS-DAT and III organic moieties could be achieved, leading to the formation of silica core with multi-shells that formed from double-silica, CS-DAT, and III dressing layers. In this sensing system, notable changes in color and reflectance intensity of the multi-shelled sensor for Cu(2+), Co(2+), Cd(2+), and Hg(2+) ions, were observed at pH 2, 8, 9.5 and 11.5, respectively. The multi-shelled sensor is added to enable accessibility for continuous monitoring of several different toxic metal ions and efficient multi-ion sensing and removal capabilities with respect to reversibility, selectivity, and signal stability. PMID:23856314

  16. Toxic metals distribution in different components of Pakistani and imported cigarettes by electrothermal atomic absorption spectrometer.

    Science.gov (United States)

    Kazi, T G; Jalbani, N; Arain, M B; Jamali, M K; Afridi, H I; Sarfraz, R A; Shah, A Q

    2009-04-15

    It was extensively investigated that a significant flux of toxic metals, along with other toxins, reaches the lungs through smoking. In present study toxic metals (TMs) (Al, Cd, Ni and Pb) were determined in different components of Pakistani local branded and imported cigarettes, including filler tobacco (FT), filter (before and after normal smoking by a single volunteer) and ash by electrothermal atomic absorption spectrometer (ETAAS). Microwave-assisted digestion method was employed. The validity and accuracy of methodology were checked by using certified sample of Virginia tobacco leaves (ICHTJ-cta-VTL-2). The percentages (%) of TMs in different components of cigarette were calculated with respect to their total contents in FT of all branded cigarettes before smoking, while smoke concentration has been calculated by subtracting the filter and ash contents from the filler tobacco content of each branded cigarette. The highest percentage (%) of Al was observed in ash of all cigarettes, with range 97.3-99.0%, while in the case of Cd, a reverse behaviour was observed, as a range of 15.0-31.3% of total contents were left in the ash of all branded cigarettes understudy. PMID:18657905

  17. Toxic metals distribution in different components of Pakistani and imported cigarettes by electrothermal atomic absorption spectrometer

    International Nuclear Information System (INIS)

    It was extensively investigated that a significant flux of toxic metals, along with other toxins, reaches the lungs through smoking. In present study toxic metals (TMs) (Al, Cd, Ni and Pb) were determined in different components of Pakistani local branded and imported cigarettes, including filler tobacco (FT), filter (before and after normal smoking by a single volunteer) and ash by electrothermal atomic absorption spectrometer (ETAAS). Microwave-assisted digestion method was employed. The validity and accuracy of methodology were checked by using certified sample of Virginia tobacco leaves (ICHTJ-cta-VTL-2). The percentages (%) of TMs in different components of cigarette were calculated with respect to their total contents in FT of all branded cigarettes before smoking, while smoke concentration has been calculated by subtracting the filter and ash contents from the filler tobacco content of each branded cigarette. The highest percentage (%) of Al was observed in ash of all cigarettes, with range 97.3-99.0%, while in the case of Cd, a reverse behaviour was observed, as a range of 15.0-31.3% of total contents were left in the ash of all branded cigarettes understudy

  18. Determination of toxic metals in clay-minerals by X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    The presence of toxic elements such as Mn, Cr, Co, Ni, As, Se, Cd and Pb have been awakening great interest, because they are frequently found in environmental materials like soils, sediments and waters. The emission of those metals can be, mainly, attributed to industries, thermoelectric plants and urban occupation sources. The study of the contamination of the soils and sediments for toxic metals is important for the preservation and conservation of those resources, once the soil is a component key of the ecosystem for the growth of the plants, degradation and recycling of the dead biomass. A method for determination of those elements in clay minerals was established. It was used x-ray fluorescence spectrometry and fundamental parameters method. This method allows to calculate the theoretical fluorescent intensities from the measured intensities of the elements present in sample, using instrumental sensitivity. The clay fraction was obtained through mineral desegregation, being deposited by gravity on a quartz substrate. This kind of sample preparation allows to obtain thin film samples, reducing drastically the matrix effects. The fundamental parameters method does not need the single element calibration curves, carrying a very fast analysis. The method presented an accuracy lower than 10%, a precision between 0.3 to 2.4% and a determination limit at the 1μg/g (author)

  19. Autophagy as an ultrastructural marker of heavy metal toxicity in human cord blood hematopoietic stem cells

    International Nuclear Information System (INIS)

    Stem cells are a key target of environmental toxicants, but little is known about their toxicological responses. We aimed at developing an in-vitro model based on adult human stem cells to identify biomarkers of heavy metal exposure. To this end we investigated the responses of human CD34+ hematopoietic progenitor cells to hexavalent chromium (Cr[VI]) and cadmium (Cd). Parallel cultures of CD34+ cells isolated from umbilical cord blood were exposed for 48 h to 0.1 μM and 10 μM Cr(VI) or Cd. Cultures treated with 10 μM Cr(VI) or Cd showed marked cell loss. Ultrastructural analysis of surviving cells revealed prominent autophagosomes/autophagolysosomes, which is diagnostic of autophagy, associated with mitochondrial damage and replication, dilatation of the rough endoplasmic reticulum and Golgi complex, cytoplasmic lipid droplets and chromatin condensation. Treated cells did not show the morphologic hallmarks of apoptosis. Treatment with 0.1 μM Cr(VI) or Cd did not result in cell loss, but at the ultrastructural level cells showed dilated endoplasmic reticulum and evidence of mitochondrial damage. We conclude that autophagy is implicated in the response of human hematopoietic stem cells to toxic concentrations of Cr(VI) and Cd. Autophagy, which mediates cell survival and death under stress, deserves further evaluation to be established as biomarker of metal exposure

  20. The behavior and toxicity of metal oxide nanoparticles in aqueous solution

    Science.gov (United States)

    Mwaanga, Phenny

    The dissolution and aggregation of metal oxides nanoparticles (NPs) in aqueous solution not only alter the abundance and toxicology of NPs, but also makes the effective assessment and the correct interpretation of effects of NPs on organisms challenging. The extent to which these processes (dissolution and aggregation) occur largely depend on pH, ionic strength, dissolved natural organic matter (NOM) and NPs characteristics. This study investigated the dissolution and aggregation behavior of the four metal oxide NPs (nZnO, nCuO, nFe2O3 and nTiO2) in aqueous solution as influenced by pH, ionic strength and NOM and examined the toxicity of these NPs to Daphnia magna and interpreted the toxicity in terms of NPs' behavior in aqueous solution. The dissolution of NPs in distilled and dionized (DDI) water, culture (FETAX) solution, solutions of varying pH, ionic strength and NOM content was investigated. Differences in the dissolution patterns in different solution conditions were observed among the NPs, with some NPs (nTiO2.) showing low dissolution under all solution conditions. Visual Minteq model showed that the distribution of dissolved metal oxides NPs species was regulated by pH and NOM. The experimental dissolution data were corroborated by Visual Minteq and by the empirical double exponent dissolution rate model. In the aggregation investigation, the aggregation behavior and fractal dimensions of the metal oxides NPs were studied in solutions such as DDI, FETAX solution, solutions of varying pH, ionic strength and NOM content. The rate of aggregation was found to increase with ionic strength and to decrease with increase in NOM concentration. Increased aggregation corresponded to lower fractal dimensions and increased sedimentation. Arising from the dissolution and aggregation investigations, the interaction of NOM with NPs in aqueous solution was examined. Specifically, the influence of the NOM on NPs dispersion at different pH values was investigated using TiO2

  1. Pelletized ponderosa pine bark for adsorption of toxic heavy metals from water

    Directory of Open Access Journals (Sweden)

    Tshabalala, M. A.

    2007-02-01

    Full Text Available Bark flour from ponderosa pine (Pinus ponderosa was consolidated into pellets using citric acid as cross-linking agent. The pellets were evaluated for removal of toxic heavy metals from synthetic aqueous solutions. When soaked in water, pellets did not leach tannins, and they showed high adsorption capacity for Cu(II, Zn(II, Cd(II, and Ni(II under both equilibrium and dynamic adsorption conditions. The experimental data for Cd(II and Zn(II showed a better fit to the Langmuir than to the Freundlich isotherm. The Cu(II data best fit the Freundlich isotherm, and the Ni(II data fitted both Freundlich and Langmuir isotherms equally. According to the Freundlich constant KF, adsorption capacity of pelletized bark for the metal ions in aqueous solution, pH 5.1 ± 0.2, followed the order Cd(II > Cu(II > Zn(II >> Ni(II; according to the Langmuir constant b, adsorption affinity followed the order Cd(II >> Cu(II ≈ Zn(II >> Ni(II. Although data from dynamic column adsorption experiments did not show a good fit to the Thomas kinetic adsorption model, estimates of sorption affinity series of the metal ions on pelletized bark derived from this model were not consistent with the series derived from the Langmuir or Freundlich isotherms and followed the order Cu(II > Zn(II ≈ Cd(II > Ni(II. According to the Thomas kinetic model, the theoretical maximum amounts of metal that can be sorbed on the pelletized bark in a column at influent concentration of ≈10 mg/L and flow rate = 5 mL/min were estimated to be 57, 53, 50, and 27 mg/g for copper, zinc, cadmium, and nickel, respectively. This study demonstrated the potential for converting low-cost bark residues to value-added sorbents using starting materials and chemicals derived from renewable resources. These sorbents can be applied in the removal of toxic heavy metals from waste streams with heavy metal ion concentrations of up to 100 mg/L in the case of Cu(II.

  2. Assessment of sediment metal contamination in the Mar Menor coastal lagoon (SE Spain: Metal distribution, toxicity, bioaccumulation and benthic community structure

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available The Mar Menor coastal lagoon is one of the largest of the Mediterranean Sea. Ancient mining activities in the mountains near its southern basin have resulted in metal contamination in the sediment. The metal bioavailability of these sediments was determined through laboratory toxicity bioassays using three Mediterranean sea urchin species and two amphipod species, and by means of field bioaccumulation measurements involving the seagrass Cymodocea nodosa. The effect of sediment metal contamination on benthic communities was assessed through benthic infaunal analyses, applying classical descriptive parameters and multivariate techniques. The sediments affected by the mining activities presented high levels of toxicity and metals were also accumulated in the seagrass tissues, pointing to metal bioavailability. Although the classical benthic indices were not clear indicators of disturbance, the multivariate techniques applied provided more consistent conclusions.

  3. Residual organic matter and microbial respiration in bottom ash: Effects on metal leaching and eco-toxicity.

    Science.gov (United States)

    Ilyas, A; Persson, K M; Persson, M

    2015-09-01

    A common assumption regarding the residual organic matter, in bottom ash, is that it does not represent a significant pool of organic carbon and, beyond metal-ion complexation process, it is of little consequence to evolution of ash/leachate chemistry. This article evaluates the effect of residual organic matter and associated microbial respiratory processes on leaching of toxic metals (i.e. arsenic, copper, chromium, molybdenum, nickel, lead, antimony and zinc), eco-toxicity of ash leachates. Microbial respiration was quantified with help of a respirometric test equipment OXITOP control system. The effect of microbial respiration on metal/residual organic matter leaching and eco-toxicity was quantified with the help of batch leaching tests and an eco-toxicity assay - Daphnia magna. In general, the microbial respiration process decreased the leachate pH and eco-toxicity, indicating modification of bioavailability of metal species. Furthermore, the leaching of critical metals, such as copper and chromium, decreased after the respiration in both ash types (fresh and weathered). It was concluded that microbial respiration, if harnessed properly, could enhance the stability of fresh bottom ash and may promote its reuse. PMID:25999368

  4. Testing an application of a biotic ligand model to predict acute toxicity of metal mixtures to rainbow trout.

    Science.gov (United States)

    Iwasaki, Yuichi; Kamo, Masashi; Naito, Wataru

    2015-04-01

    The authors tested the applicability of a previously developed biotic ligand model (BLM) to predict acute toxicity of single metals and metal mixtures (cadmium, lead, and zinc) to rainbow trout fry (Oncorhynchus mykiss) from a single available dataset. The BLM used in the present study hypothesizes that metals inhibit an essential cation (calcium) and organisms die as a result of its deficiency, leading to an assumption that the proportion of metal-binding ligand (f) is responsible for the toxic effects of metals on the survival of rainbow trout. The f value is a function of free-ion concentrations of metals computed by a chemical speciation model, and the function has affinity constants as model parameters. First, the survival effects of single metals were statistically modeled separately (i.e., f-survival relationship) by using the generalized linear mixed model with binomial distribution. The modeled responses of survival rates to f overlapped reasonably irrespective of metals tested, supporting the theoretical prediction from the BLM that f-survival relationships are comparable regardless of metal species. The authors thus developed the generalized linear mixed model based on all data pooled across the single-metal tests. The best-fitted model well predicted the survival responses observed in mixture tests (r = 0.97), providing support for the applicability of the BLM to predict effects of metal mixtures. PMID:25323464

  5. Quantitative analysis of potentially toxic metals in alginates for dental use

    Directory of Open Access Journals (Sweden)

    A. S. BRAGA

    2009-01-01

    Full Text Available

    Alginate is one the materials most employed in practice to make dental impressions. Substances like zinc, cadmium and lead silicate, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern as regards their toxicity. The most serious chronic effect of oral exposure to cadmium is renal toxicity. Assimilation of lead has deleterious effects on the gastrointestinal tract, hematopoietic system, cardiovascular system, central and peripheral nervous systems, kidneys, immune system, and reproductive system. Chronic oral exposures to zinc have resulted in hypochromic and microcyte anemia in some individuals. The aim of the present study was to measure the cadmium, lead and zinc contents of seven brands of alginate for dental use on sale in Brazil. The samples were weighed and placed in the Teflon cups of a closedsystem microwave oven. Aqua regia (4mL concentrated HCl:HNO3, 3:1 v/v and hydrofluoric acid (2mL concentrated HF were added to the samples, which were then subjected to heating. The samples were then cooled to room temperature and diluted to 25 mL in deionized water in a volumetric glass flask. The samples were diluted in duplicate and analyzed against a reagent blank. The analyses were performed in an atomic absorption flame spectrophotometer. Neither lead nor cadmium was detected. Zinc contents ranged from 0.001% to 1.36% by weight. The alginates exhibited low contents of the metals under study and gave no cause for concern regarding toxicity; even so, it is advisable to monitor potentially toxic materials continually and to analyze their plasmatic levels in the professionals working with them. Keywords: Cadmium, lead, zinc, alginates, intoxication, irreversible hydrocolloid.

  6. Some inferences from in vivo experiments with metal and metal oxide nanoparticles: the pulmonary phagocytosis response, subchronic systemic toxicity and genotoxicity, regulatory proposals, searching for bioprotectors (a self-overview

    Directory of Open Access Journals (Sweden)

    Katsnelson BA

    2015-04-01

    Full Text Available Boris A Katsnelson,1 Larisa I Privalova,1 Marina P Sutunkova,1 Vladimir B Gurvich,1 Nadezhda V Loginova,1 Ilzira A Minigalieva,1 Ekaterina P Kireyeva,1 Vladimir Y Shur,2 Ekaterina V Shishkina,2 Ya B Beikin,3 Oleg H Makeyev,4 Irene E Valamina4 1The Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Ekaterinburg, Russia; 2The Institute of Natural Sciences, The Ural Federal University, Ekaterinburg, Russia; 3The City Clinical Diagnostics Centre, Ekaterinburg, Russia; 4The Ural State Medical University, Ekaterinburg, Russia Abstract: The purpose of this paper is to overview and summarize previously published results of our experiments on white rats exposed to either a single intratracheal instillation or repeated intraperitoneal injections of silver, gold, iron oxide, copper oxide, nickel oxide, and manganese oxide nanoparticles (NPs in stable water suspensions without any chemical additives. Based on these results and some corroborating data of other researchers we maintain that these NPs are much more noxious on both cellular and systemic levels as compared with their 1 µm or even submicron counterparts. However, within the nanometer range the dependence of systemic toxicity on particle size is intricate and non-unique due to complex and often contra-directional relationships between the intrinsic biological aggressiveness of the specific NPs, on the one hand, and complex mechanisms that control their biokinetics, on the other. Our data testify to the high activity of the pulmonary phagocytosis of NPs deposited in airways. This fact suggests that safe levels of exposure to airborne NPs are possible in principle. However, there are no reliable foundations for establishing different permissible exposure levels for particles of different size within the nanometric range. For workroom air, such permissible exposure levels of metallic NP can be proposed at this stage, even if tentatively, based on a sufficiently

  7. Dioxins, metals, and fish toxicity in ash residue from space heaters burning used motor oil.

    Science.gov (United States)

    Delistraty, Damon; Stone, Alex

    2007-06-01

    Ash residue, generated from burning used motor oil, is a complex and ubiquitous waste stream. Ash samples were collected from space heaters and analyzed for dioxins (N=10), expressed as toxic equivalents (TEQ), and heavy metals (N=9). TEQ averaged 148-164 ng kg(-1) (standard deviation [SD] 385-416 ng kg(-1)), depending on methods used for non-detects (NDs) and toxic equivalency factors (TEFs). It is notable that median TEQ (2.89-3.49 ng kg(-1)) was about 50 fold lower, reflecting the influence of several high end values on the mean. The proportion of NDs among 17 polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in each sample averaged 38.2% (range 0-94.1%). Total metals averaged 103,000 mg kg(-1) (SD 26,600 mg kg(-1)), with Zn, Cu, and Pb contributing 89.3%, 6.4%, and 3.0% of the total, respectively. Rainbow trout bioassays resulted in median mortalities of 3.2% and 42.0% (respective SD 25.3% and 43.2%) at ash concentrations of 10 and 100 mg l(-1), respectively. Nominal concentrations of several metals (e.g., Cu, Zn) in the fish bioassay exceeded their reported median lethal concentrations (LC50s) for the test species. Multiple regressions (Bonferroni Pmetals (e.g., As, Cd, Pb), and TEQ. Mean TEQ concentration in used oil ash ranked on the high end of TEQ content in other environmental matrices, including wood ash, cement kiln dust, biosolids, and soils. Overall, these results suggest that suitable disposal methods are needed for ash generated from burning used motor oil. PMID:17350666

  8. Some inferences from in vivo experiments with metal and metal oxide nanoparticles: the pulmonary phagocytosis response, subchronic systemic toxicity and genotoxicity, regulatory proposals, searching for bioprotectors (a self-overview)

    Science.gov (United States)

    Katsnelson, Boris A; Privalova, Larisa I; Sutunkova, Marina P; Gurvich, Vladimir B; Loginova, Nadezhda V; Minigalieva, Ilzira A; Kireyeva, Ekaterina P; Shur, Vladimir Y; Shishkina, Ekaterina V; Beikin, Ya B; Makeyev, Oleg H; Valamina, Irene E

    2015-01-01

    The purpose of this paper is to overview and summarize previously published results of our experiments on white rats exposed to either a single intratracheal instillation or repeated intraperitoneal injections of silver, gold, iron oxide, copper oxide, nickel oxide, and manganese oxide nanoparticles (NPs) in stable water suspensions without any chemical additives. Based on these results and some corroborating data of other researchers we maintain that these NPs are much more noxious on both cellular and systemic levels as compared with their 1 μm or even submicron counterparts. However, within the nanometer range the dependence of systemic toxicity on particle size is intricate and non-unique due to complex and often contra-directional relationships between the intrinsic biological aggressiveness of the specific NPs, on the one hand, and complex mechanisms that control their biokinetics, on the other. Our data testify to the high activity of the pulmonary phagocytosis of NPs deposited in airways. This fact suggests that safe levels of exposure to airborne NPs are possible in principle. However, there are no reliable foundations for establishing different permissible exposure levels for particles of different size within the nanometric range. For workroom air, such permissible exposure levels of metallic NP can be proposed at this stage, even if tentatively, based on a sufficiently conservative approach of decreasing approximately tenfold the exposure limits officially established for respective micro-scale industrial aerosols. It was shown that against the background of adequately composed combinations of some bioactive agents (comprising pectin, multivitamin-multimineral preparations, some amino acids, and omega-3 polyunsaturated fatty acid) the systemic toxicity and even genotoxicity of metallic NPs could be markedly attenuated. Therefore we believe that, along with decreasing NP-exposures, enhancing organisms’ resistance to their adverse action with the help

  9. Protective action of low-intensity laser radiation relative to the toxic effect of metals (experimental study in vitro)

    Science.gov (United States)

    Dejneka, S. Y.

    1997-12-01

    The study of a possible cytotoxic effect of different doses of low-insensitive laser radiation and protective action of low-intensive laser radiation relative to the toxic effect of metals was carried out by means of the alternative method of investigation in vitro on cell cultura Hela. It was established that the investigated doses of low-intensive laser radiation had not produced any toxic effect on cell culture Hela, so the mentioned doses were not cytotoxic. It was revealed that laser radiation reduced the level of the cytotoxic effect of the studied metal salts on the cell culture, and possessed the protective action against the toxic effect of metals. This action has a clear-cut dose- related character.

  10. Microbial fuel cell driving electrokinetic remediation of toxic metal contaminated soils.

    Science.gov (United States)

    Habibul, Nuzahat; Hu, Yi; Sheng, Guo-Ping

    2016-11-15

    An investigation of the feasibility of in-situ electrokinetic remediation for toxic metal contaminated soil driven by microbial fuel cell (MFC) is presented. Results revealed that the weak electricity generated from MFC could power the electrokinetic remediation effectively. The metal removal efficiency and its influence on soil physiological properties were also investigated. With the electricity generated through the oxidation of organics in soils by microorganisms, the metals in the soils would mitigate from the anode to the cathode. The concentrations of Cd and Pb in the soils increased gradually through the anode to the cathode regions after remediation. After about 143days and 108 days' operation, the removal efficiencies of 31.0% and 44.1% for Cd and Pb at the anode region could be achieved, respectively. Soil properties such as pH and soil conductivity were also significantly redistributed from the anode to the cathode regions. The study shows that the MFC driving electrokinetic remediation technology is cost-effective and environmental friendly, with a promising application in soil remediation. PMID:27388419

  11. Multivariate analysis of potentially toxic metals in sediments of a tropical coastal lagoon.

    Science.gov (United States)

    Oyeyiola, A O; Davidson, C M; Olayinka, K O; Oluseyi, T O; Alo, B I

    2013-03-01

    Surface sediments collected from the Lagos Lagoon, Nigeria, and three adjoining rivers were analysed for their physicochemical properties and pseudo-total concentration of the potentially toxic metals (PTM) Cd, Cr, Cu, Pb and Zn. The concentration of the PTM varied seasonally and spatially. Odo-Iyaalaro was observed to be the most polluted river, with highest concentrations of 42.1 mg kg(-1), 102 mg kg(-1), 185 mg kg(-1), 154 mg kg(-1) and 1040 mg kg(-1) of Cd, Cr, Cu, Pb and Zn, respectively, while Ibeshe River was the least contaminated, apart from a site affected by Cu from the textile industry. Some of the sediments were found to be above the consensus-based probable effect concentrations and Dutch sediment guideline for metals. Overall metal concentrations were similar to those reported for other tropical lagoon and estuarine systems affected by anthropogenic inputs as a result of rapid urbanisation. Due to the large number of samples, principal component analysis was used to examine relationships within the data set. Generally, sediments collected during the dry season were observed to have higher concentration of PTM than those collected during the rainy season. This means that PTM could accumulate over a prolonged period and then be released relatively rapidly, on an annual basis, into tropical lagoon systems. PMID:22628107

  12. Metales pesados y toxicidad de aguas del Río Aconcagua en Chile Heavy metals and toxicity of waters of the Aconcagua River in Chile

    Directory of Open Access Journals (Sweden)

    Hernán Gaete

    2007-08-01

    Full Text Available The toxicity of surface waters in a zone with mining activity in the Aconcagua River was determined through growth inhibition bioassays of Pseudokirchneriella subcapitata, and correlated with heavy metal concentrations. Results show that the waters near the discharge of the mining effluent displayed toxicity during all periods of study; the molybdenum and copper concentration exceeded the norms of water quality. The correlations between the concentrations of metals and the growth rate of P. subcapitata varied in the different periods of the study; inverse and significant correlations with copper stand out in some periods.

  13. Seasonal variation of Sarpa salpa fish toxicity, as related to phytoplankton consumption, accumulation of heavy metals, lipids peroxidation level in fish tissues and toxicity upon mice.

    Science.gov (United States)

    Bellassoued, Khaled; Hamza, Asma; van Pelt, Jos; Elfeki, Abdelfatteh

    2013-02-01

    The aim of this work was to investigate for Sarpa salpa the seasonal trend in the food sources, heavy metals bioaccumulation and the oxidative stress in the organs. In addition, the toxicity was assessed by mouse bioassay of extract of the fish's organs collected in autumn, the peak of occurrence of hallucinatory syndrome. The toxicity was further studied for compounds present in epiphyte collected from the sea at the end of spring and in summer that are digested by the S. salpa in these seasons. We observed a higher lipid peroxydation in different tissues of S. salpa compared to the control fish Diplodus annularis. Furthermore, heavy metals accumulation in organs of these fish showed a significant variation between the two species (P ciguatoxin (neurotoxins) extracts of viscera, liver, brain and muscle of S. salpa were as follows: 1.217, 2.195, 14.395, 18.645 g/kg mouse, respectively. We noticed a significant correlation (P < 0.05) between the total amount of toxic dinoflagellates and the level of TBARS in the liver, the brain and the muscle, this for all seasons and all sizes. Moreover, the cytotoxic effect observed for epiphytes extract confirms the transfer of toxins originating from toxic dinoflagellates, which live as epiphytes on P. oceanica leaves, to the fish by grazing. Our work indicates that, toxic phytoplanktons and heavy metals accumulation are responsible for the increase of oxidative stress in the organs of S. salpa. Hence, the edible part of S. salpa, especially the viscera and liver, can cause a threat to human health, and consumption should, for this reason, be dissuaded. PMID:22535366

  14. Re-evaluation of metal bioaccumulation and chronic toxicity in Hyalella azteca using saturation curves and the biotic ligand model

    Energy Technology Data Exchange (ETDEWEB)

    Borgmann, U.; Norwood, W.P.; Dixon, D.G

    2004-10-01

    Bioaccumulation by Hyalella of all metals studied so far in our laboratory was re-evaluated to determine if the data could be explained satisfactorily using saturation models. Saturation kinetics are predicted by the biotic ligand model (BLM), now widely used in modelling acute toxicity, and are a pre-requisite if the BLM is to be applied to chronic toxicity. Saturation models provided a good fit to all the data. Since these are mechanistically based, they provide additional insights into metal accumulation mechanisms not immediately apparent when using allometric models. For example, maximum Cd accumulation is dependent on the hardness of the water to which Hyalella are acclimated. The BLM may need to be modified when applied to chronic toxicity. Use of saturation models for bioaccumulation, however, also necessitates the need for using saturation models for dose-response relationships in order to produce unambiguous estimates of LC50 values based on water and body concentrations. This affects predictions of toxicity at very low metal concentrations and results in lower predicted toxicity of mixtures when many metals are present at low concentrations.

  15. Metal toxicity differently affects the Iris pseudacorus-arbuscular mycorrhiza fungi symbiosis in terrestrial and semi-aquatic habitats.

    Science.gov (United States)

    Wężowicz, K; Turnau, K; Anielska, T; Zhebrak, I; Gołuszka, K; Błaszkowski, J; Rozpądek, P

    2015-12-01

    Phytoremediation offers an environmental friendly alternative to conventional cleanup techniques. In this study, mycorrhizal fungi isolated from the roots of Mentha longifolia grown in the basin of the Centuria River (S Poland) were used. Iris pseudacorus was grown in substratum from an industrial waste, enriched in Pb, Fe, Zn, and Cd in a terrestrial and water-logged habitat. Plant yield and photosynthetic performance was the highest in the aquatic environment; however, the presence of toxic metals (TM) negatively affected photosystem II (PSII) photochemistry as shown by the JIP test. Fungi colonization and Cd accumulation within plant tissues was decreased. In the terrestrial habitat, neither arbuscular mycorrhizal fungi (AMF) nor metal toxicity affected plant growth, although metal uptake, Cd in particular, as well as photosynthesis were affected. Inoculated plants accumulated significantly more Cd, and photosynthesis was downregulated. The results presented in this study clearly indicate that the I. pseudacorus-AMF symbiosis adapts itself to the presence of toxic metals in the environment, optimizing resource supply, energy fluxes, and possibly stress tolerance mechanisms. Plant/AMF consortia grown in terrestrial and water-logged habitats utilize different strategies to cope with metal toxicity. The use of AMF in improving the phytoremediation potential of I. pseudacorus needs, however, further research. PMID:26585452

  16. Evaluation of toxic metals in the industrial effluents and their segregation through peanut husk fence for pollution abatement

    International Nuclear Information System (INIS)

    The industrial pollution is exponentially growing in the developing countries due to the discharge of untreated effluents from the industries in the open atmosphere. This may cause severe health hazards in the general public. To reduce this effect, it is essential to remove the toxic and heavy metals from the effluents before their disposal into the biosphere. In this context, samples of the effluents were collected from the textile/yarn, ceramics and pulp/paper industries and the concentrations of the toxic metal ions were determined using neutron activation analysis (NAA) technique. The observed concentration values of the As, Cr and Fe ions, in the unprocessed industrial effluents, were 4.91 ± 0.8, 9.67 ± 0.7 and 9.71 ± 0.8 mg/L, respectively which was well above the standard recommended limits (i.e. 1.0, 1.0 and 2.0 mg/L, respectively). In order to remove the toxic metal ions from the effluents, the samples were treated with pea nut husk fence. After this treatment, 91.5% arsenic, 81.9% chromium and 66.5% iron metal ions were successfully removed from the effluents. Then the treated effluents contained concerned toxic metal ions concentrations within the permissible limits as recommended by the national environmental quality standards (NEQS). (author)

  17. Interference of CuO nanoparticles with metal homeostasis in hepatocytes under sub-toxic conditions

    Science.gov (United States)

    Cuillel, Martine; Chevallet, Mireille; Charbonnier, Peggy; Fauquant, Caroline; Pignot-Paintrand, Isabelle; Arnaud, Josiane; Cassio, Doris; Michaud-Soret, Isabelle; Mintz, Elisabeth

    2014-01-01

    Copper oxide nanoparticles (CuO-NP) were studied for their toxicity and mechanism of action on hepatocytes (HepG2), in relation to Cu homeostasis disruption. Indeed, hepatocytes, in the liver, are responsible for the whole body Cu balance and should be a major line of defence in the case of exposure to CuO-NP. We investigated the early responses to sub-toxic doses of CuO-NP and compared them to equivalent doses of Cu added as salt to see if there is a specific nano-effect related to Cu homeostasis in hepatocytes. The expression of the genes encoding the Cu-ATPase ATP7B, metallothionein 1X, heme oxygenase 1, heat shock protein 70, superoxide dismutase 1, glutamate cysteine ligase modifier subunit, metal responsive element-binding transcription factor 1 and zinc transporter 1 was analyzed by qRT-PCR. These genes are known to be involved in response to Cu, Zn and/or oxidative stresses. Except for MTF1, ATP7B and SOD1, we clearly observed an up regulation of these genes expression in CuO-NP treated cells, as compared to CuCl2. In addition, ATP7B trafficking from the Golgi network to the bile canaliculus membrane was observed in WIF-B9 cells, showing a need for Cu detoxification. This shows an increase in the intracellular Cu concentration, probably due to Cu release from endosomal CuO-NP solubilisation. Our data show that CuO-NP enter hepatic cells, most probably by endocytosis, bypassing the cellular defence mechanism against Cu, thus acting as a Trojan horse. Altogether, this study suggests that sub-toxic CuO-NP treatments induce successively a Cu overload, a Cu-Zn exchange on metallothioneins and MTF1 regulation on both Cu and Zn homeostasis.Copper oxide nanoparticles (CuO-NP) were studied for their toxicity and mechanism of action on hepatocytes (HepG2), in relation to Cu homeostasis disruption. Indeed, hepatocytes, in the liver, are responsible for the whole body Cu balance and should be a major line of defence in the case of exposure to CuO-NP. We investigated

  18. Stress and toxicity of biologically important transition metals (Co, Ni, Cu and Zn) on phytoplankton in a tropical freshwater system: An investigation with pigment analysis by HPLC

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Babu, P.V.R.; Acharyya, T.; Bandyopadhyay, D.

    Stress and toxicity of four biologically important transition metals (Co, Ni, Cu and Zn) on phytoplankton in Godavari River (a tropical freshwater system) were studied to understand the fate of phytoplankton of freshwater if it receives metal...

  19. Heavy and toxic metals in the ground water of the Prilep region from the Pelagonija valley

    International Nuclear Information System (INIS)

    The research presented in this study was carried out in order to test the quality of the ground water in the Prilep region within the Pelagonija valley. The investigations consisted of taking 12 individual samples of ground water and analysis of eleven elements from the group of toxic metals, such as: Mn, Fe, Zn, Pb, Cr, Cu, Cd, As, Al, Ni and Ag. Knowing the quality of ground water in this investigated region is of particular importance since the ground water from the analyzed wells is used by the locals of this region as drinking water and for irrigation of the surrounding arable land. The data we received indicates that in the majority of analyzed samples there were increased concentrations of Ni, As and Pb, which are most likely result of the composition of the geological environment where this ground water circulates. (Author)

  20. Toxic metals' concentration in water of Kriveljska Reka and its tributaries and influence of water there

    International Nuclear Information System (INIS)

    Kriveljska reka is near Bor, a big mining basin in East Serbia. This river is formed from two not so big rivers: Cerova reka and Valja Mare. Kriveljska reka flow past village Veliki Krivelj. Veliki Krivelj is one of the most important mining strip in Bor area. Therefore, Kriveljska reka is the reception for waste waters of some sections of Mining Basin Bor, situated on its banks. We will present to you concentrations of 7 toxic metals, pH-value and chemical oxygen demand in 8 points at Kriveljska reka and waste waters' influence on quality of this river's water. Based on our results, we can conclude that waste waters from Mining Basin Bor contaminate Kriveljska reka and at last we have a dead river. (author)

  1. Effects of a chelating resin on metal bioavailability and toxicity to estuarine invertebrates: Divergent results of field and laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Wilkie, Emma M., E-mail: ewilkie@bio.mq.edu.a [Department of Environmental Sciences, University of Technology Sydney, Broadway, NSW 2007 (Australia); Ecotoxicology and Environmental Contaminants Section, Department of Environment and Climate Change, Lidcombe, NSW 1825 (Australia); Roach, Anthony C. [Ecotoxicology and Environmental Contaminants Section, Department of Environment and Climate Change, Lidcombe, NSW 1825 (Australia); Micevska, Tina [Centre for Environmental Contaminants Research, CSIRO Land and Water, Menai, NSW 2234 (Australia); Kelaher, Brendan P.; Bishop, Melanie J. [Department of Environmental Sciences, University of Technology Sydney, Broadway, NSW 2007 (Australia)

    2010-05-15

    Benthic invertebrates can uptake metals through diffusion of free ion solutes, or ingestion of sediment-bound forms. This study investigated the efficacy of the metal chelating resin SIR 300{sup TM} in adsorbing porewater metals and isolating pathways of metal exposure. A field experiment (Botany Bay, Sydney, Australia) and a laboratory toxicity test each manipulated the availability of porewater metals within contaminated and uncontaminated sediments. It was predicted that within contaminated sediments, the resin would adsorb porewater metals and reduce toxicity to invertebrates, but in uncontaminated sediments, the resin would not significantly affect these variables. Whereas in the laboratory, the resin produced the predicted results, in the field the resin increased porewater metal concentrations of contaminated sediments for at least 34 days and decreased abundances of four macroinvertebrate groups, and richness in all sediments. These contrasting findings highlight the limits of extrapolating the results of laboratory experiments to the field environment. - Laboratory experiments do not predict the effects on porewater metals or macroinvertebrates of adding a chelating resin to metal-contaminated field sediments.

  2. Effects of a chelating resin on metal bioavailability and toxicity to estuarine invertebrates: Divergent results of field and laboratory tests

    International Nuclear Information System (INIS)

    Benthic invertebrates can uptake metals through diffusion of free ion solutes, or ingestion of sediment-bound forms. This study investigated the efficacy of the metal chelating resin SIR 300TM in adsorbing porewater metals and isolating pathways of metal exposure. A field experiment (Botany Bay, Sydney, Australia) and a laboratory toxicity test each manipulated the availability of porewater metals within contaminated and uncontaminated sediments. It was predicted that within contaminated sediments, the resin would adsorb porewater metals and reduce toxicity to invertebrates, but in uncontaminated sediments, the resin would not significantly affect these variables. Whereas in the laboratory, the resin produced the predicted results, in the field the resin increased porewater metal concentrations of contaminated sediments for at least 34 days and decreased abundances of four macroinvertebrate groups, and richness in all sediments. These contrasting findings highlight the limits of extrapolating the results of laboratory experiments to the field environment. - Laboratory experiments do not predict the effects on porewater metals or macroinvertebrates of adding a chelating resin to metal-contaminated field sediments.

  3. Phytochelatin synthase is required for tolerating metal toxicity in a basidiomycete yeast and is a conserved factor involved in metal homeostasis in fungi

    OpenAIRE

    Shine, Alaina M; Shakya, Viplendra PS; Idnurm, Alexander

    2015-01-01

    Background Phytochelatin synthase (PCS) is an enzyme that catalyzes the biosynthesis of phytochelatin from glutathione. Phytochelatins protect cells against the toxic effects of non-essential heavy metals, such as cadmium, and hence growth is restricted in the presence of these metals in mutants in PCS-encoding genes. PCS genes from fungi have been characterized in only two species in the Ascomycota, and these genes are considered sparsely distributed in the fungal kingdom. Results A gene enc...

  4. Simultaneous estimation of trace and toxic metals through drinking water from Tarapur using ICP-AES

    International Nuclear Information System (INIS)

    In the present paper the contamination levels of trace and toxic metals in drinking water collected from Tarapur industrial area, Thane were investigated. The concentrations of trace and toxic metals (Pb, Cd, Cu, Cr, Ni, Se, V, Zn, Mn, Mo, Co, As and Ba) were determined simultaneously using Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The results were compared with international water quality guidelines (WHO, 2008) and were found within the permissible limits. The quality assurance was checked by standard addition method and spike recovery. The concentration of Pb, Cd, Cu, Cr, Ni, Se, V, Zn, Mn, Mo, Co, As and Ba varies from 4.25-19.62 μg/L, 0.13-1.49 μg/L, 0.60-65.55 μg/L, 0.46-4.15 μg/L, <0.1 μg/L, 0.5- 9.35 μg/L, <0.5 μg/L, 3.41-99.64 μg/L, 0.80-9.62 μg/L, 0.30-1.48 μg/L, <0.1-0.90 μg/L, <0.63 μg/L and 0.71-9.0 μg/L respectively. Similarly Na, K, Ca and Mg varies from 8.83-61.54 mg/L, 0.40-27.66 mg/L, 14.63-223.75 mg/L and 9.56-67.06 mg/L in different places around Tarapur. (author)

  5. Microbial leaching of toxic metals and arsenic from a heap consisting of heavily polluted soil

    Science.gov (United States)

    Groudev, Stoyan; Georgiev, Plamen; Spasova, Irena; Nicolova, Marina

    2014-05-01

    Soil heavily polluted with toxic heavy metals (mainly Cu, Zn, Cd) and arsenic was subjected to microbial cleanup in a heap specially constructed for this purpose. The heap was located on an impermeable geomembrane, had the shape of a truncated pyramid and contained about 240 tons of soil collected mainly from the horizon A. The soil was highly acidic (with an initial pH of about 3.2) and was preliminarily crushed to minus 2.5 cm particle size. The pollutants were present mainly as the relevant sulphide minerals and the soil was inhabited by different microorganisms, including some acidophilic chemolithotrophic bacteria able to oxidize sulphides and to solubilize the relevant toxic elements. The heap possessed systems for irrigation and aeration and was surrounded by ditches to collect the drainage heap effluents containing the dissolved pollutants. The treatment of the soil was carried out by means of interrupted irrigation with leach solutions containing diluted sulphuric acid (to maintain pH in the heap within the range of about 2.5 - 2.8) and ammonium and phosphate ions to maintain the microbial growth. The treatment was carried out for a period of about two years during different climatic seasons. After the end of leaching the soil was subjected to some conventional melioration procedures such as liming, grassing, moulching, addition of fertilizers and animal manure and periodic ploughing and irrigation to increase its quality to levels suitable for agricultural utilization.

  6. Effect of Extraction Variables on the Biodegradable Chelant-Assisted Removal of Toxic Metals from Artificially Contaminated European Reference Soils

    OpenAIRE

    Begum, Zinnat A.; Rahman, Ismail M. M.; Sawai, Hikaru; Mizutani, Satoshi; Maki, Teruya; Hasegawa, Hiroshi

    2013-01-01

    Development of aminopolycarboxylate chelants (APCs) having enhanced biodegradability is gaining increasing focus to replace the EDTA and its homologs with those used widely for the ex situ treatment of contaminated soils and are potential eco-threats. The paper reports the chelant-assisted extraction of the toxic metals (Cd, Cu, Pb, and Zn) from the metal-spiked European reference soils (Eurosoil 1 and Eurosoil 4) using biodegradable APCs, namely EDDS, GLDA, and HIDS. The effects of chelant-t...

  7. Comparison of the extraction efficiencies of different leaching agents for reliable assessment of bio-accessible trace metal fractions in airborne particulate matter

    Directory of Open Access Journals (Sweden)

    Mukhtar A.

    2013-04-01

    Full Text Available In present study, an in-vitro physiologically based extraction test has been applied for extraction of bio-accessible trace metal fractions in airborne particulate matter (APM samples collected from different urban sites in Austria and Pakistan using the leaching agents H2O, sodium chloride, ammonium acetate, ammonium citrate, synthetic gastric juice and artificial lung fluids. Obtained extracts were then measured using an ETV-ICP-OES procedure which allowed highly sensitive measurement of dissolved analytes even in the presence of leaching agents. Derived results indicated that the investigated leaching agents extract different amounts of trace metals. In general, leaching agents with organic nature yielded comparatively greater extractable and thus bio-accessible trace metal fractions to that of simple solvents like H2O or aqueous NaCl solution. With water, only 26.3±4.0% of Cd was found to be bio-accessible whereas 88.4±24.8 of Cd was obtained as bio-accessible fraction with the use of synthetic gastric juice. The concentrations of bio-accessible metal fractions varied from 0.4 ng m−3 (Cd to 714 ng m−3 (Zn and 0.3 ng m−3 (Cd to 190 ng m−3 (Zn for PM10 samples collected from Karachi (Pakistan and Graz (Austria respectively.

  8. Spatial–temporal variations, sources, and transport of airborne inhalable metals (PM10 in urban and rural areas of northern China

    Directory of Open Access Journals (Sweden)

    X. S. Luo

    2014-05-01

    Full Text Available Atmospheric particle pollution is a serious environmental issue in China, especially the northern regions. Ambient air loadings (ng m−3, pollution sources and apportionment, and transport pathways of trace (Cd, Co, Cu, Ni, Pb, V, and Zn and major (Al, Ca, Fe, and Mg metals associated with inhalable particulate matters (PM10 aerosols were characterized in urban, rural village, and rural field areas of seven cities (from inland in the west to the coast in the east: Wuwei, Yinchuan, Taiyuan, Beijing, Dezhou, Yantai, and Dalian across northern China by taking one 72 h sample each site within a month for a whole year (April 2010 to March 2011. Ambient PM10 pollution in northern China is especially significant in the cold season (October–March due to the combustion of coal for heating and dust storms in the winter and spring. Owing to variations in emission intensity and meteorological conditions, there is a trend of decrease in PM10 levels in cities from west to east. Both air PM10 and the associated metal loadings for urban and rural areas were comparable, showing that the current pattern of regional pollution in China differs from the decreasing urban–rural-background transect that is usual in other parts of the world. The average metal levels are Zn (276 ng m−3 ≫ Pb (93.7 ≫ Cu (54.9 ≫ Ni (9.37 > V (8.34 ≫ Cd (2.84 > Co (1.76. Judging from concentrations (mg kg−1, enrichment factors (EFs, a multivariate statistical analysis (principal component analysis, PCA, and a receptor model (absolute principal component scores-multiple linear regression analysis, APCS-MLR, the airborne trace metals (Zn, Pb, Cu, and Cd in northern China were mainly anthropogenic, and mostly attributable to coal combustion and vehicle emissions with additional industrial sources. However, the Co was mostly of crustal origin, and the V and Ni were mainly from soil/dust in the western region and mostly from the petrochemical industry/oil combustion in the east

  9. Spatial-temporal variations, sources, and transport of airborne inhalable metals (PM10) in urban and rural areas of northern China

    Science.gov (United States)

    Luo, X. S.; Ip, C. C. M.; Li, W.; Tao, S.; Li, X. D.

    2014-05-01

    Atmospheric particle pollution is a serious environmental issue in China, especially the northern regions. Ambient air loadings (ng m-3), pollution sources and apportionment, and transport pathways of trace (Cd, Co, Cu, Ni, Pb, V, and Zn) and major (Al, Ca, Fe, and Mg) metals associated with inhalable particulate matters (PM10 aerosols) were characterized in urban, rural village, and rural field areas of seven cities (from inland in the west to the coast in the east: Wuwei, Yinchuan, Taiyuan, Beijing, Dezhou, Yantai, and Dalian) across northern China by taking one 72 h sample each site within a month for a whole year (April 2010 to March 2011). Ambient PM10 pollution in northern China is especially significant in the cold season (October-March) due to the combustion of coal for heating and dust storms in the winter and spring. Owing to variations in emission intensity and meteorological conditions, there is a trend of decrease in PM10 levels in cities from west to east. Both air PM10 and the associated metal loadings for urban and rural areas were comparable, showing that the current pattern of regional pollution in China differs from the decreasing urban-rural-background transect that is usual in other parts of the world. The average metal levels are Zn (276 ng m-3) ≫ Pb (93.7) ≫ Cu (54.9) ≫ Ni (9.37) > V (8.34) ≫ Cd (2.84) > Co (1.76). Judging from concentrations (mg kg-1), enrichment factors (EFs), a multivariate statistical analysis (principal component analysis, PCA), and a receptor model (absolute principal component scores-multiple linear regression analysis, APCS-MLR), the airborne trace metals (Zn, Pb, Cu, and Cd) in northern China were mainly anthropogenic, and mostly attributable to coal combustion and vehicle emissions with additional industrial sources. However, the Co was mostly of crustal origin, and the V and Ni were mainly from soil/dust in the western region and mostly from the petrochemical industry/oil combustion in the east. The

  10. Toxic Metals up taken by Cabbage Grown in Irrigated Farmlands of Kaduna Metropolis, Nigeria

    Directory of Open Access Journals (Sweden)

    W.L.O. Jimoh

    2012-12-01

    Full Text Available Heavy metals such as cadmium, lead, iron and zinc were investigated in soil and lettuce obtained from irrigated farmlands of Kaduna metropolis. Concentrations of heavy metals were determined using atomic absorption spectrophotometer. The results obtained were compared with limit recommended by FAO/WHO standard (2007 so as to ascertain the extent of their pollution. The level of cadmium in cabbage ranged from 0.04-1.20μg/g. The concentrations of lead was found to be in range of 0.61-3.87 μg/g ,these were above the limit stipulated by WHO while iron concentration ranged from 0.50-12.40μg/g and zinc 2.72:g/g-18.53μg/g were within the recommended limit given by the FAO/WHO standard. This suggests that consumers of cabbage grown in the studied areas might be liable to lead and cadmium toxicity as at the time of this research work. Pearson correlation shows positive correlation between soil and cabbage in these irrigation sites.

  11. The accumulation of metals and toxic effects in Nereis virens exposed to pulverised fuel ash.

    Science.gov (United States)

    Jenner, H A; Bowmer, T

    1992-05-01

    The marine polychaete worm Nereis virens was used to study the bioaccumulation patterns of metal exposures with pulverised fuel ash (PFA). Juvenile N. virens were exposed for 12 weeks to sediments comprised of 100% PFA, 50% PFA-50% clean sand, a reference sediment (contaminated harbour-dredged material) and a clean sand control. Mortality after the first 4 weeks was high at 32-45% in the four sediments. However, this declined to a few percent during the following 8 weeks. Growth expressed as biomass (wet weight) was reduced in bout PFA treatments and the reference sediment. Heavy metal accumulation in the tissues of N. virens was characterised as follows: a group of elements showed negligible to low accumulation (Cd, Cr, Ni, and Zn), As and Cu wich showed a definite, but moderate accumulation: and finally Se, which showed a low accumulation rate, where an uptake equilibrium was not reached after 9 weeks. It is concluded that acute toxic effects did not occur but a population of N. virens inhabiting a PFA dumping site could be affected by high Se concentrations. PMID:24234402

  12. Thermochemical Studies of the Toxic Action of Heavy Metal Ions on Escherichia coli by Microcalorimetry

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    By using an LKB2277 BioActivity Monitor (heat conduction microcalorimeter),stopped-flow method,the thermogenetic curves of Escherichia coli growth at 37℃ inhibited by four kinds of heavy metal ions are determined,and parameters such as growth rate constants,inhibitory ratio,half-inhibitory concentration etc.were obtained.The experimental results show that heavy metal ions can inhibit Escherichia coli growth obviously,but low concentration of Cu2+ has a promoting action.The half inhibitory concentrations of Zn2+,Cd2+,Hg2+and Cu2+ are 28.3,10.9,3.19 and 69.6μg.mL-1,respectively.Judged from the rate constant,the half-inhibitory concentration and the molecular mass,the inhibitory sequence is Hg2+>Cd2+>Zn2+>Cu2+.This microclorimetric bioassay for acute cellular toxicity is based on metabolic heat evolution from cultured cells.The assay is quantitative,inexpensive,and versatile;moreover,toxicological information can be obtained with cell from other species of interest.

  13. Examination of heavy and toxic metals in the Kozjak Lake and Treska River with protection measures

    International Nuclear Information System (INIS)

    The aim of our study was to examine the situation with heavy metals in water and stream sediment of Kozjak lake and Treska river, and to recommend measures to prevent pollution. Water quality and sediment was examined of aspect of the content of six very important chemical elements known as heavy and toxic metals, including: lead (Pb), cadmium (Cd), chromium (Cr), iron (Fe), copper (Cu) and arsenic (As). Modern methods of laboratory testing of chemical elements were applied: Atomic absorption spectroscopy, atomic emission spectrometry method with double plasma (AES-ICP) method and the atomic absorption spectrometry electro thermal (ETAAS). Total of 120 samples were analyzed in water and 48 samples in stream sediments. The paper will also indicate measures to protect the Kozjak lake and Treska river from possible contamination. Especially significant role for Kozjak Lake was building the Dam for production of electricity HPP ''Kozjak'', which is the biggest artificial dam in the country. But despite this, the Kozjak lake already used as protection from floods Skopje, fishing, eco-lake tourism but need to think and plan about using for potable water for irrigation of crops, but also as an alternative water supply of the city of Skopje. (Author)

  14. The history of airborne lead and other heavy metals as revealed from sediments of Lake Vähä-Pitkusta, SW Finland

    Directory of Open Access Journals (Sweden)

    Anu Hakala

    2004-01-01

    Full Text Available Lake Vähä-Pitkusta is a small, sheltered, relative deep and undisturbed lake in SW Finland. It was cored to investigate airborne deposition of heavy metals, which is not known in detail in this area. We analysed lake sediments to detect trends in the historicalload of lead, cadmium, zinc, copper, nickel and vanadium and compared the deposition pattern described earlier from other parts of Europe. Sediments were dated using AMS radiocarbon and 137Cs-dating techniques. The results indicate that lead emissions during Roman and Medieval times reached Finland; this was detected for the firsttime. Medieval deposition of lead was associated with that of cadmium and zinc, suggesting their origin as long distance airborne load. Copper, nickel and vanadium deposition patterns are recent, because their strong increase of accumulation was detected only in the sediments representing the last 50 years. Most probably they originate from local pollutant sources. Overall, the results emphasize the potential value of small, sheltered headwater lakes as archives of atmospheric environmental impacts.

  15. Building Toxic Metal Characterization and Decontamination Report: Area 6, Building 914

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Industrial Hygiene

    2011-08-15

    The purpose of this report is to outline the toxic metal characterization and decontamination efforts in Area 6, Building 914. This includes the initial building inspection, the hotspot sampling, results/findings, building cleanup, and the verification sampling. Building 914 is a steel light frame building that was constructed in 1992. It is about 16,454 square feet, and five employees are assigned to this building. According to the building's floor plan blueprints, it could be inferred that this building was once a Wiremen/Lineman shop. In 2002-2004, the National Nuclear Security Administration Nevada Site Office embarked on a broad characterization of beryllium (Be) surface concentrations throughout the North Las Vegas Facility, the Nevada National Security Site (NNSS), and ancillary facilities like the Special Technologies Laboratory, Remote Sensing Laboratory, etc. Building 914 was part of this characterization. The results of the 2002 study illustrated that the metal housekeeping limits were within acceptable limits and from a Be standpoint, the building was determined to be fit for occupancy. On March 2, 2011, based on a request from Building 914 users, National Security Technologies, LLC (NSTec) Industrial Hygiene (IH) collected bulk samples from the southwest corner of Building 914 at heights above 6 feet where black dust had been noticed on this particular wall. IH conducted surface swipe sampling of the area and analyzed the samples for toxic metals, namely, beryllium (Be), cadmium (Cd), chromium (Cr), lead (Pb), and manganese (Mn). The sample results indicated values two to four times above the housekeeping threshold for Be, Cd, Cr, Pb, and Mn. Subsequently, the facility was closed and posted; the necessary personnel were notified; and controls were instituted for ingress and egress of the building. On March 17, 2011, IH performed an extensive sampling event involving the entire warehouse in accordance with NSTec Organization Procedure OP-P250

  16. Bioaccumulation and tolerance characteristics of a submerged plant (Ceratophyllum demersum L.) exposed to toxic metal lead.

    Science.gov (United States)

    Chen, Min; Zhang, Ling-Lei; Li, Jia; He, Xiao-Jia; Cai, Jun-Chi

    2015-12-01

    A hydroponic study was conducted to investigate the lead bioaccumulation and tolerance characteristics of Ceratophyllum demersum L. exposed to various lead concentrations (5-80 μM) for 7, 14 or 21 days. Lead accumulation increased with increasing concentrations of metal in the solution, to a maximum accumulation of 4016.4 mg kg(-1) dw. Unexpectedly, the release of accumulated lead from the plants into solution was observed for all experimental groups except those exposed to 5 μM. Both the biomass and protein content of the plants responded significantly to lead stress. Malondialdehyde (MDA) levels increased substantially at lead concentrations below 20 μM, further indicating that this metal is toxic to the plants. To reveal the mechanism underlying the defense against lead stress, plants were also assayed for the activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), as well as other relevant enzymes such as phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO). The activities of both SOD and CAT increased at lower lead concentrations and with shorter exposure times, followed by a decline, but the activities of POD and its isoenzymes continued to increase under all conditions. Moreover, increases in the activities of PAL and PPO were observed only for the 14-day treatment, and these two enzymes were not sensitive to lead concentration. These results suggest that C. demersum exhibits strong tolerance within a specific concentration range of lead in solution; according to regression analysis, 40 μM is suggested to be this plant's tolerance threshold for lead in water. Furthermore, the malfunction of this tolerance mechanism might accelerate the metal-release process. These attributes are likely to be beneficial for utilizing C. demersum in phytoremediation applications. PMID:26300117

  17. Endothelial Function and Serum Concentration of Toxic Metals in Frequent Consumers of Fish

    Science.gov (United States)

    Buscemi, Silvio; Vasto, Sonya; Di Gaudio, Francesca; Grosso, Giuseppe; Bergante, Sonia; Galvano, Fabio; Massenti, Fatima Maria; Amodio, Emanuele; Rosafio, Giuseppe; Verga, Salvatore

    2014-01-01

    Background Endothelial dysfunction is involved in the pathogenesis of atherosclerosis. Consumption of fish is associated with reduced cardiovascular risk, but there is paucity of data concerning its effect on endothelial function. Furthermore, investigation of the effects of fish consumption on health must take into account the ingestion of contaminants, including transition metals and some metalloids, which may have unfavorable effects on health, including those on the cardiovascular system. We investigated the association between fish consumption, endothelial function (flow mediated dilation of the brachial artery), and serum concentration of some toxic metals in apparently healthy people. Methods Twenty-nine high fish consumers (at least 3 portions a week) were compared with 25 low fish consumers (less than 1 portion a week). All participants were free of diabetes, cardiovascular or other systemic diseases. Serum metal (antimonium, arsenic, mercury, lead, cobalt, copper, zinc, selenium, strontium) concentrations were measured in subgroups of 24 high fish consumers and 19 low fish consumers. Results Both groups exhibited similar habitual dietary patterns, age and anthropometric characteristics. The high fish consumers had higher flow mediated dilation (9.7±1.8 vs. 7.3±1.9%; P<0.001), but also higher serum concentrations of mercury (5.87±2.69 vs. 1.65±1.10 mcg/L; P<0.001) and arsenic (6.04±3.25 vs. 2.30±1.58 mcg/L; P<0.001). The fasting plasma glucose concentrations were significantly correlated with both mercury (r = 0.39; P = 0.01) and arsenic concentrations (r = 0.55; P<0.001). Conclusions Habitual consumption of high amounts of fish is associated with better endothelial function despite higher serum concentrations of mercury and arsenic. PMID:25401695

  18. Human health and ecological toxicity potentials due to heavy metal content in waste electronic devices with flat panel displays

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Seong-Rin [Department of Chemical Engineering and Materials Science, University of California, 2017 Kemper Hall, One Shields Avenue, Davis, CA 95616 (United States); Schoenung, Julie M., E-mail: jmschoenung@ucdavis.edu [Department of Chemical Engineering and Materials Science, University of California, 2017 Kemper Hall, One Shields Avenue, Davis, CA 95616 (United States)

    2010-05-15

    Display devices such as cathode-ray tube (CRT) televisions and computer monitors are known to contain toxic substances and have consequently been banned from disposal in landfills in the State of California and elsewhere. New types of flat panel display (FPD) devices, millions of which are now purchased each year, also contain toxic substances, but have not previously been systematically studied and compared to assess the potential impact that could result from their ultimate disposal. In the current work, the focus is on the evaluation of end-of-life toxicity potential from the heavy metal content in select FPD devices with the intent to inform material selection and design-for-environment (DfE) decisions. Specifically, the metals antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, mercury, molybdenum, nickel, selenium, silver, vanadium, and zinc in plasma TVs, LCD (liquid crystal display) TVs, LCD computer monitors and laptop computers are considered. The human health and ecotoxicity potentials are evaluated through a life cycle assessment perspective by combining data on the respective heavy metal contents, the characterization factors in the U.S. EPA Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI), and a pathway and impact model. Principal contributors to the toxicity potentials are lead, arsenic, copper, and mercury. Although the heavy metal content in newer flat panel display devices creates less human health toxicity potential than that in CRTs, for ecological toxicity, the new devices are worse, especially because of the mercury in LCD TVs and the copper in plasma TVs.

  19. Human health and ecological toxicity potentials due to heavy metal content in waste electronic devices with flat panel displays

    International Nuclear Information System (INIS)

    Display devices such as cathode-ray tube (CRT) televisions and computer monitors are known to contain toxic substances and have consequently been banned from disposal in landfills in the State of California and elsewhere. New types of flat panel display (FPD) devices, millions of which are now purchased each year, also contain toxic substances, but have not previously been systematically studied and compared to assess the potential impact that could result from their ultimate disposal. In the current work, the focus is on the evaluation of end-of-life toxicity potential from the heavy metal content in select FPD devices with the intent to inform material selection and design-for-environment (DfE) decisions. Specifically, the metals antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, mercury, molybdenum, nickel, selenium, silver, vanadium, and zinc in plasma TVs, LCD (liquid crystal display) TVs, LCD computer monitors and laptop computers are considered. The human health and ecotoxicity potentials are evaluated through a life cycle assessment perspective by combining data on the respective heavy metal contents, the characterization factors in the U.S. EPA Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI), and a pathway and impact model. Principal contributors to the toxicity potentials are lead, arsenic, copper, and mercury. Although the heavy metal content in newer flat panel display devices creates less human health toxicity potential than that in CRTs, for ecological toxicity, the new devices are worse, especially because of the mercury in LCD TVs and the copper in plasma TVs.

  20. Determination of heavy metals concentrations in airborne particulates matter (APM) from Manjung district, Perak using energy dispersive X-ray fluorescence (EDXRF) spectrometer

    Science.gov (United States)

    Arshad, Nursyairah; Hamzah, Zaini; Wood, Ab. Khalik; Saat, Ahmad; Alias, Masitah

    2015-04-01

    Airborne particulates trace metals are considered as public health concern as it can enter human lungs through respiratory system. Generally, any substance that has been introduced to the atmosphere that can cause severe effects to living things and the environment is considered air pollution. Manjung, Perak is one of the development districts that is active with industrial activities. There are many industrial activities surrounding Manjung District area such as coal fired power plant, quarries and iron smelting which may contribute to the air pollution into the environment. This study was done to measure the concentrations of Hg, U, Th, K, Cu, Fe, Cr, Zn, As, Se, Pb and Cd in the Airborne Particulate Matter (APM) collected at nine locations in Manjung District area within 15 km radius towards three directions (North, North-East and South-East) in 5 km intervals. The samples were collected using mini volume air sampler with cellulose filter through total suspended particulate (TSP). The sampler was set up for eight hours with the flow rate of 5 L/min. The filter was weighed before and after sample collection using microbalance, to get the amount of APM and kept in desiccator before analyzing. The measurement was done using calibrated Energy Dispersive X-Ray Fluorescence (EDXRF) Spectrometer. The air particulate concentrations were found below the Malaysia Air Quality Guidelines for TSP (260 µg/m3). All of the metals concentrations were also lower than the guidelines set by World Health Organization (WHO), Ontario Ministry of the Environment and Argonne National Laboratory, USA NCRP (1975). From the concentrations, the enrichment factor were calculated.

  1. A suite of recombinant luminescent bacterial strains for the quantification of bioavailable heavy metals and toxicity testing

    Directory of Open Access Journals (Sweden)

    Kahru Anne

    2009-05-01

    Full Text Available Abstract Background Recombinant whole-cell sensors have already proven useful in the assessment of the bioavailability of environmental pollutants like heavy metals and organic compounds. In this work 19 recombinant bacterial strains representing various Gram-positive (Staphylococcus aureus and Bacillus subtilis and Gram-negative (Escherichia coli, Pseudomonas fluorescens bacteria were constructed to express the luminescence encoding genes luxCDABE (from Photorhabdus luminescens as a response to bioavailable heavy metals ("lights-on" metal sensors containing metal-response elements, 13 strains or in a constitutive manner ("lights-off" constructs, 6 strains. Results The bioluminescence of all 13 "lights-on" metal sensor strains was expressed as a function of the sub-toxic metal concentrations enabling the quantitative determination of metals bioavailable for these strains. Five sensor strains, constructed for detecting copper and mercury, proved to be target metal specific, whereas eight other sensor strains were simultaneously induced by Cd2+, Hg2+, Zn2+and Pb2+. The lowest limits of determination of the "lights-on" sensor strains for the metals tested in this study were (μg l-1: 0.002 of CH3HgCl, 0.03 of HgCl2, 1.8 of CdCl2, 33 of Pb(NO32, 1626 of ZnSO4, 24 of CuSO4 and 340 of AgNO3. In general, the sensitivity of the "lights-on" sensor strains was mostly dependent on the metal-response element used while the selection of host bacterium played a relatively minor role. In contrast, toxicity of metals to the "lights-off" strains was only dependent on the bacterial host so that Gram-positive strains were remarkably more sensitive than Gram-negative ones. Conclusion The constructed battery of 19 recombinant luminescent bacterial strains exhibits several novel aspects as it contains i metal sensor strains with similar metal-response elements in different host bacteria; ii metal sensor strains with metal-response elements in different copies and iii

  2. Metal impurities provide useful tracers for identifying exposures to airborne single-wall carbon nanotubes released from work-related processes

    International Nuclear Information System (INIS)

    This study investigated the use of metal impurities in single-wall carbon nanotubes (SWCNT) as potential tracers to distinguish engineered nanomaterials from background aerosols. TEM and SEM were used to characterize parent material and aerosolized agglomerates collected on PTFE filters using a cascade impactor. SEM image analysis indicated that the SWCNT agglomerates contained about 45% amorphous carbon and backscatter electron analysis indicated that metal impurities were concentrated within the amorphous carbon component. Two elements present as impurities (Y and Ni) were selected as appropriate tracers in this case as their concentrations were found to be highly elevated in the SWCNT parent material (% range) compared to ambient air particles (μg/g range), and background air concentrations were below detection limits for both elements. Bioaccessibility was also determined using physiologically-based extractions at pH conditions relevant to both ingestion and inhalation pathways. A portable wet electrostatic precipitation system effectively captured airborne Y and Ni released during sieving processes, in proportions similar to the bulk sample. These observations support the potential for catalysts and other metal impurities in carbon nanotubes to serve as tracers that uniquely identify emissions at source, after an initial analysis to select appropriate tracers.

  3. Use of Azolla to assess toxicity and accumulation of metals from artificial and natural sediments containing cadmium, copper, and zinc

    Energy Technology Data Exchange (ETDEWEB)

    Powell, G.M. [S.M. Stoller Corp., Boulder, CO (United States); Nimmo, D.W.R.; Flickinger, S.A.; Brinkman, S.F.

    1998-12-31

    The aquatic macrophyte Azolla mexicana was studied to determine if it could indicate toxicity and bioavailability of cadmium, copper, and zinc in sediments. Plants were exposed to metal-fortified artificial sediment and to natural sediment contaminated with tailings from a Superfund site near Deer Lodge, Montana. Dry weights (mass) of biomass were used to determine effects of the metal concentrations and tissue metals were measured to determine metal uptake from the sediments. Plants exposed to artificial sediments fortified with cadmium and copper showed the greatest reduction in dry mass while zinc showed the least. And, plants exposed to copper singly in artificial sediments lost both zinc and cadmium for their tissues. Plants exposed to metal-contaminated natural sediment developed necrotic and chlorotic tissue within 24 hours in 75% and 100% dilutions but significant effects (P < 0.0001) using dry mass were found as low as 3.13%.

  4. Biotic ligand modeling approach: Synthesis of the effect of major cations on the toxicity of metals to soil and aquatic organisms.

    Science.gov (United States)

    Ardestani, Masoud M; van Straalen, Nico M; van Gestel, Cornelis A M

    2015-10-01

    The biotic ligand model (BLM) approach is used to assess metal toxicity, taking into account the competition of other cations with the free metal ions for binding to the biotic ligand sites of aquatic and soil organisms. The bioavailable fraction of metals, represented by the free metal ion, is a better measure than the total concentration for assessing their potential risk to the environment. Because BLMs are relating toxicity to the fraction of biotic ligands occupied by the metal, they can be useful for investigating factors affecting metal bioaccumulation and toxicity. In the present review, the effects of major cations on the toxicity of metals to soil and aquatic organisms were comprehensively studied by performing a meta-analysis of BLM literature data. Interactions at the binding sites were shown to be species- and metal-specific. The main factors affecting the relationships between toxicity and conditional binding constants for metal binding at the biotic ligand appeared to be Ca(2+) , Mg(2+) , and protons. Other important characteristics of the exposure medium, such as levels of dissolved organic carbon and concentrations of other cations, should also be considered to obtain a proper assessment of metal toxicity to soil and aquatic organisms. PMID:25953362

  5. Pollution and health risk of potentially toxic metals in urban road dust in Nanjing, a mega-city of China

    International Nuclear Information System (INIS)

    Spatial variations in concentrations of a suite of potentially toxic metals (Ba, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and Ca in road dusts (n = 99) from urban trunk roads (TR) in Nanjing, a mega-city in China, were established. Metal pollution levels, sources and human health risk (non-carcinogenic) were studied. In contrast to previous studies, we labeled the indicative metals relating to non-exhaust traffic emissions by comparing metal pollution between crossroad and park road dusts, and then anthropogenic sources of metals in TR dusts were assessed combining their spatial pollution patterns, principal component analysis and Pb isotopic compositions. Results showed that the metals were enriched in TR dusts compared to background soil concentrations with mean enrichment factors (EFs) of 2.2–23, indicating considerable anthropogenic influence. The degrees of metal pollution ranged from minimal to extremely high and ranked by Ca > Cu > Pb ≈ Zn > Cr ≈ Fe > Ni ≈ Ba > Mn on average. Pollution of Cr, Cu, Fe, Mn, Ni, Pb and Zn in TR dusts resulted primarily from industrial emissions (e.g., coal combustion and smelting) and high pollution levels were found close to suburb industrial complexes, whereas pollution of Ba and Ca was mainly related to construction/demolition sources and was generally distributed homogeneously. The relatively minor contribution of non-exhaust traffic emissions to metal pollution in TR dusts was considered to be due to overwhelming industrial and construction/demolition contributions, as well as to the dilution effect of natural soil particles. Ingestion appears to be the major route of exposure for road dust for both adults and children, followed by dermal contact. The non-carcinogenic health risk resulting from exposure to the potentially toxic metals in TR dusts was within the safe level based on the Hazard Index (HI), except in pollution hotspots where exposure to Pb, Cr, and Cu may be hazardous to children. - Highlights: • Pollution and

  6. Pollution and health risk of potentially toxic metals in urban road dust in Nanjing, a mega-city of China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Enfeng, E-mail: efliu@niglas.ac.cn [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China); Yan, Ting [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Birch, Gavin [School of Geosciences, University of Sydney, Sydney, NSW 2006 (Australia); Zhu, Yuxin [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China)

    2014-04-01

    Spatial variations in concentrations of a suite of potentially toxic metals (Ba, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and Ca in road dusts (n = 99) from urban trunk roads (TR) in Nanjing, a mega-city in China, were established. Metal pollution levels, sources and human health risk (non-carcinogenic) were studied. In contrast to previous studies, we labeled the indicative metals relating to non-exhaust traffic emissions by comparing metal pollution between crossroad and park road dusts, and then anthropogenic sources of metals in TR dusts were assessed combining their spatial pollution patterns, principal component analysis and Pb isotopic compositions. Results showed that the metals were enriched in TR dusts compared to background soil concentrations with mean enrichment factors (EFs) of 2.2–23, indicating considerable anthropogenic influence. The degrees of metal pollution ranged from minimal to extremely high and ranked by Ca > Cu > Pb ≈ Zn > Cr ≈ Fe > Ni ≈ Ba > Mn on average. Pollution of Cr, Cu, Fe, Mn, Ni, Pb and Zn in TR dusts resulted primarily from industrial emissions (e.g., coal combustion and smelting) and high pollution levels were found close to suburb industrial complexes, whereas pollution of Ba and Ca was mainly related to construction/demolition sources and was generally distributed homogeneously. The relatively minor contribution of non-exhaust traffic emissions to metal pollution in TR dusts was considered to be due to overwhelming industrial and construction/demolition contributions, as well as to the dilution effect of natural soil particles. Ingestion appears to be the major route of exposure for road dust for both adults and children, followed by dermal contact. The non-carcinogenic health risk resulting from exposure to the potentially toxic metals in TR dusts was within the safe level based on the Hazard Index (HI), except in pollution hotspots where exposure to Pb, Cr, and Cu may be hazardous to children. - Highlights: • Pollution and

  7. The use of nuclear and related techniques for the studies of airborne particulate matter in workplace including tissue analysis and possible impacts on human health in a metal industry

    International Nuclear Information System (INIS)

    Various processes in a metal industry may produce gases and fine airborne particulate matter that hazardous to human health. The present study deals with assessment of levels and health effects of airborne particulate matter in a metal industry. The objective is achieved by determination of elemental levels in blood, nail and hair of workers and airborne particulate matter that are collected from their workplace. The elemental levels in blood, nail and hair of the workers will be compared to those of control. Their health condition are examined by medical examination and biochemical analysis of their blood. The blood was drawn following an overnight fast before breakfast, by means of I.V. catheter into three polyethylene tubes. The blood samples in the first tubes were sent to clinical laboratory for biochemical examination. Those in the second and third tubes, which are considered free from metal contamination by the needle of the catheter, are used for trace element study. Sera in the polyethylene tubes were separated from erythrocyte by centrifugation, then cooled by liquid nitrogen and freeze dried. Approximately 1 g of toe nail and hair samples were taken respectively from every worker. To eliminate grease and surface contamination the hair samples were rinse with acetone. Airborne particulate samples were collected from the workplace using Gent sampler. These samples are ready for elemental analysis. Results of biochemical analysis and medical examinations of the workers are presented in this report. The correlation among various parameters will be determined by statistical analysis. (author)

  8. Studies of toxic metals removal in industrial wastewater after electron-beam treatment

    International Nuclear Information System (INIS)

    The Advanced Oxidation Process, using electron-beam, have been studied by scientific community due to its capacity to mineralize the toxic organic compound from highly reactive radical's formation. The electron-beam treatment process has been adopted by several countries for organic compounds removal and to effluents and sewers biological degradation. In this work, studies of metals removal in the simulated aqueous solutions and in the actual industrial effluents were carried out, using electron-beam treatment. The effluents samples were collected at ETE/SABESP (Governmental Wastewater Treatment Plant) in Suzano, SP city. The sampling was outlined at three distinctive sites: Industrial Receiver Unit, Medium Bar, and Final Effluent. The effluents samples were irradiated using different irradiation doses (20, 50, 100, 200 and 500 kGy). The removal behavior of metals Ca, CI, S, P, K, Al, Fe, As, Ni, Cr, Zn, Si, Co, Mn, As, Se, Cd, Hg and Pb was verified. The elements determination was accomplished with the x-ray fluorescence (WD-XRFS) technique using Fundamental Parameters method and thin film samples. The elements Fe, Zn, Cr and Co presented a removal > 99% to 200 kGy of irradiation dose in industrial effluent. At the same dose, P, Al and Si presented a removal of 81.8%, 97.6% and 98.7%, respectively. Ca and S were removed more than 80% at 20 kGy and Na, CI and K did not presented any degree of removal. As, Se, Cd, Hg and Pb removal was studied in the simulated aqueous solutions and industrial effluents with scavengers addition (EDTA and HCOONa). The elements As and Hg presented a removal of 92% and 99%, respectively, with HCOONa, at 500 kGy irradiation dose. The Se presented a 96.5% removal at same irradiation dose without scavengers addition. The removal of Cd and Pb did not give a significant removal, once all of the assay were carried out in the oxidant medium. (author)

  9. Effects of acid-volatile sulfide on metal bioavailability and toxicity to midge (Chironomus tentans) larvae in black shale sediments

    Science.gov (United States)

    Ogendi, G.M.; Brumbaugh, W.G.; Hannigan, R.E.; Farris, J.L.

    2007-01-01

    Metal bioavailability and toxicity to aquatic organisms are greatly affected by variables such as pH, hardness, organic matter, and sediment acid-volatile sulfide (AVS). Sediment AVS, which reduces metal bioavailability and toxicity by binding and immobilizing metals as insoluble sulfides, has been studied intensely in recent years. Few studies, however, have determined the spatial variability of AVS and its interaction with simultaneously extracted metals (SEM) in sediments containing elevated concentrations of metals resulting from natural geochemical processes, such as weathering of black shales. We collected four sediment samples from each of four headwater bedrock streams in northcentral Arkansa (USA; three black shale-draining streams and one limestone-draining stream). We conducted 10-d acute whole-sediment toxicity tests using the midge Chironomus tentans and performed analyses for AVS, total metals, SEMs, and organic carbon. Most of the sediments from shale-draining streams had similar total metal and SEM concentrations but considerable differences in organic carbon and AVS. Zinc was the leading contributor to the SEM molar sum, averaging between 68 and 74%, whereas lead and cadmium contributed less than 3%. The AVS concentration was very low in all but two samples from one of the shale streams, and the sum of the SEM concentrations was in molar excess of AVS for all shale stream sediments. No significant differences in mean AVS concentrations between sediments collected from shale-draining or limestone-draining sites were noted (p > 0.05). Midge survival and growth in black shale-derived sediments were significantly less (p < 0.001) than that of limestone-derived sediments. On the whole, either SEM alone or SEM-AVS explained the total variation in midge survival and growth about equally well. However, survival and growth were significantly greater (p < 0.05) in the two sediment samples that contained measurable AVS compared with the two sediments from the

  10. Assessment of metal toxicity and bioavailability in metallophyte leaf litters and metalliferous soils using Eisenia fetida in a microcosm study.

    Science.gov (United States)

    Nirola, Ramkrishna; Megharaj, Mallavarapu; Venkateswarlu, Kadiyala; Aryal, Rupak; Correll, Ray; Naidu, Ravi

    2016-07-01

    The leaf litters of tree species, Acacia pycnantha (Ap) and Eucalyptus camaldulensis (Ec), predominantly growing at an abandoned copper (Cu) mine and mine soils including controls, were assessed for determining the metal toxicity and bioavailability using earthworm species Eisenia fetida, in a microcosm. Significant reduction in body weight as well as mortality were observed when the worms were introduced into mine soil or its combination with mine Ap litter. Virtually, there were no juveniles when the worms were fed on substratum that contained mine soil or mine leaf litter. The extent of bioaccumulation was dependent on water-soluble fraction of a metal in soil. The accumulation of cadmium, lead and copper in worm tissue was significantly more in treatments that received mine soil with or without mine leaf litter. However, the tissue concentration of zinc did not differ much in earthworms irrespective of its exposure to control or contaminated samples. Mine leaf litter from Ec, a known Cu hyperaccumulator, was more hospitable to earthworm survival and juvenile than that of Ap litter. Validation of the data on bioaccumulation of metals indicated that the mine leaf litter significantly contributed to metal bioavailability. However, it was primarily the metal concentration in mine soil that was responsible for earthworm toxicity and bioavailability. Our data also indicate that detrivores like earthworm is greatly responsible for heavy metal transfer from mines into the ecosystem. PMID:27057994

  11. Iron sulfide attenuates the methanogenic toxicity of elemental copper and zinc oxide nanoparticles and their soluble metal ion analogs.

    Science.gov (United States)

    Gonzalez-Estrella, Jorge; Gallagher, Sara; Sierra-Alvarez, Reyes; Field, Jim A

    2016-04-01

    Elemental copper (Cu(0)) and zinc oxide (ZnO) nanoparticle (NP) toxicity to methanogens has been attributed to the release of soluble metal ions. Iron sulfide (FeS) partially controls the soluble concentration of heavy metals and their toxicity in aquatic environments. Heavy metals displace the Fe from FeS forming poorly soluble metal sulfides in the FeS matrix. Therefore, FeS may be expected to attenuate the NP toxicity. This work assessed FeS as an attenuator of the methanogenic toxicity of Cu(0) and ZnO NPs and their soluble salt analogs. The toxicity attenuation capacity of fine (25-75μm) and coarse (500 to 1200μm) preparations of FeS (FeS-f and FeS-c respectively) was tested in the presence of highly inhibitory concentrations of CuCl2, ZnCl2 Cu(0) and ZnO NPs. FeS-f attenuated methanogenic toxicity better than FeS-c. The results revealed that 2.5× less FeS-f than FeS-c was required to recover the methanogenic activity to 50% (activity normalized to uninhibited controls). The results also indicated that a molar FeS-f/Cu(0) NP, FeS-f/ZnO NP, FeS-f/ZnCl2, and FeS-f/CuCl2 ratio of 2.14, 2.14, 4.28, and 8.56 respectively, was necessary to recover the methanogenic activity to >75%. Displacement experiments demonstrated that CuCl2 and ZnCl2 partially displaced Fe from FeS. As a whole, the results indicate that not all the sulfide in FeS was readily available to react with the soluble Cu and Zn ions which may explain the need for a large stoichiometric excess of FeS to highly attenuate Cu and Zn toxicity. Overall, this study provides evidence that FeS attenuates the toxicity caused by Cu(0) and ZnO NPs and their soluble ion analogs to methanogens. PMID:26803736

  12. Toxicity of proton-metal mixtures in the field: Linking stream macroinvertebrate species diversity to chemical speciation and bioavailability

    International Nuclear Information System (INIS)

    Understanding metal and proton toxicity under field conditions requires consideration of the complex nature of chemicals in mixtures. Here, we demonstrate a novel method that relates streamwater concentrations of cationic metallic species and protons to a field ecological index of biodiversity. The model WHAM-FTOX postulates that cation binding sites of aquatic macroinvertebrates can be represented by the functional groups of natural organic matter (humic acid), as described by the Windermere Humic Aqueous Model (WHAM6), and supporting field evidence is presented. We define a toxicity function (FTOX) by summing the products: (amount of invertebrate-bound cation) x (cation-specific toxicity coefficient, αi). Species richness data for Ephemeroptera, Plecoptera and Trichoptera (EPT), are then described with a lower threshold of FTOX, below which all organisms are present and toxic effects are absent, and an upper threshold above which organisms are absent. Between the thresholds the number of species declines linearly with FTOX. We parameterised the model with chemistry and EPT data for low-order streamwaters affected by acid deposition and/or abandoned mines, representing a total of 412 sites across three continents. The fitting made use of quantile regression, to take into account reduced species richness caused by (unknown) factors other than cation toxicity. Parameters were derived for the four most common or abundant cations, with values of αi following the sequence (increasing toxicity) H+ + and Al, FTOX shows a steady decline with increasing pH, crossing the lower threshold near to pH 7. Competition effects among cations mean that toxicity due to Cu and Zn is rare at lower pH values, and occurs mostly between pH 6 and 8.

  13. Toxicity of proton-metal mixtures in the field: Linking stream macroinvertebrate species diversity to chemical speciation and bioavailability

    Energy Technology Data Exchange (ETDEWEB)

    Stockdale, Anthony [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Tipping, Edward, E-mail: et@ceh.ac.uk [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Lofts, Stephen [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Ormerod, Stephen J. [Catchment Research Group, Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3US (United Kingdom); Clements, William H. [Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80523 (United States); Blust, Ronny [Ecophysiology, Biochemistry and Toxicology Group, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

    2010-10-01

    Understanding metal and proton toxicity under field conditions requires consideration of the complex nature of chemicals in mixtures. Here, we demonstrate a novel method that relates streamwater concentrations of cationic metallic species and protons to a field ecological index of biodiversity. The model WHAM-F{sub TOX} postulates that cation binding sites of aquatic macroinvertebrates can be represented by the functional groups of natural organic matter (humic acid), as described by the Windermere Humic Aqueous Model (WHAM6), and supporting field evidence is presented. We define a toxicity function (F{sub TOX}) by summing the products: (amount of invertebrate-bound cation) x (cation-specific toxicity coefficient, {alpha}{sub i}). Species richness data for Ephemeroptera, Plecoptera and Trichoptera (EPT), are then described with a lower threshold of F{sub TOX}, below which all organisms are present and toxic effects are absent, and an upper threshold above which organisms are absent. Between the thresholds the number of species declines linearly with F{sub TOX}. We parameterised the model with chemistry and EPT data for low-order streamwaters affected by acid deposition and/or abandoned mines, representing a total of 412 sites across three continents. The fitting made use of quantile regression, to take into account reduced species richness caused by (unknown) factors other than cation toxicity. Parameters were derived for the four most common or abundant cations, with values of {alpha}{sub i} following the sequence (increasing toxicity) H{sup +} < Al < Zn < Cu. For waters affected mainly by H{sup +} and Al, F{sub TOX} shows a steady decline with increasing pH, crossing the lower threshold near to pH 7. Competition effects among cations mean that toxicity due to Cu and Zn is rare at lower pH values, and occurs mostly between pH 6 and 8.

  14. Sediment quality in the Douro river estuary based on trace metal contents, macrobenthic community and elutriate sediment toxicity test (ESTT).

    Science.gov (United States)

    Mucha, Ana P; Bordalo, Adriano A; Vasconcelos, M Teresa S D

    2004-07-01

    The aim of this study was to evaluate the sediment quality in the mesotidal Douro River estuarine environment, in order to identify areas where sediment contamination could cause ecosystem degradation. Samples were obtained in five locations and sediment characterised for grain size, total organic matter, total-recoverable metals (Al, Fe, Cu, Pb, Cr, Ni, Cd, Zn and Mn), as well as acid volatile sulfide (AVS) and simultaneously extracted metals (SEM). In situ effects were evaluated by examining the macrobenthic community structure. An elutriate sediment toxicity test (ESTT) was used to estimate the amount of metals and nutrients that could be exchanged with the water column through resuspension, and its positive or negative effects on the growth of the micro-alga Emiliania huxleyi in a 10 day test. Anthropogenic metal contamination was identified at the north bank of the Douro estuary, with deleterious effects on the macrobenthic community, namely decrease in number of species and diversity. This contamination could possibly also be toxic for water column organisms, in case of resuspension, as shown by the ESTT. Sediments from the salt marsh at the south bank showed an impoverished macrobenthic community and elutriate toxicity, which appeared to be due to anaerobic conditions. This study clearly shows the usefulness of the ESST approach to assess the biological effect of resuspension of estuarine sediments. PMID:15237288

  15. Brains of Native and Alien Mesocarnivores in Biomonitoring of Toxic Metals in Europe

    Science.gov (United States)

    Kalisinska, Elzbieta; Lanocha-Arendarczyk, Natalia; Kosik-Bogacka, Danuta; Budis, Halina; Podlasinska, Joanna; Popiolek, Marcin; Pirog, Agnieszka; Jedrzejewska, Ewa

    2016-01-01

    Mercury (Hg), lead (Pb) and cadmium (Cd) are involved in mammalian brain damage. However, little is known about Pb and Cd brain levels in wildlife that reflect the geochemical background. The aims of the study include the estimation of Hg, Pb and Cd concentrations, and the determination of relationships between these elements in the brains of 94 mesocarnivores. Road-killed or hunted animals were obtained from north-western Poland near the Polish-German border. The investigation covered the native Eurasian otter Lutra lutra, badger Meles meles, pine marten Martes martes, beech marten M. foina, European polecat Mustela putorius, red fox Vulpes vulpes, and alien species: feral and ranch American mink Neovison vison, raccoon Procyon lotor and raccoon dog Nyctereutes procyonoides. Depending on the diet and environmental pollution, the carnivore brains accumulated toxic metals in varying amounts. The highest median Hg levels (in mg/kg dry weight, dw) were found in the piscivorous Eurasian otter and feral mink (2.44 and 3.96), Pb in the omnivorous raccoon (0.47), while Cd in minks (~0.06). We indicated that Pb-based ammunition is a significant source of the element in scavengers from hunting area, and we also found a significant correlation between Pb and Cd levels in the fox brain. Finally, this study is the first to suggest background levels for brain Pb and Cd in mesocarnivores (<0.50 and <0.04 mg/kg dw, respectively). PMID:27513467

  16. The Response of Artificial Aging to Sorption Properties of Biochar for Potentially Toxic Heavy Metals

    Directory of Open Access Journals (Sweden)

    Frišták Vladimír

    2014-12-01

    Full Text Available This paper evaluates the effect of simulated conditions of artificial aging on sorption capacity of two types of biochar. These were produced by slow pyrolysis from different feedstock - beech wood chips (BC A and garden green waste residues (BC B. Cadmium served as a model for potentially toxic metals. Twenty freeze-thaw cycles were used to simulate physical aging. The determination of biochar physicochemical properties showed main changes in CEC and SA values of aged sorbents. The maximum sorption capacities of aged BC A sorbent were higher by about 26 % and aged BC B sorbent by about 20% compared to Qmax of non-aged biochar. Qmax of aged BC B peaked at 9.4 mg g-1 whereas BC A sorbed significantly less Cd. FT-IR analyses confirmed the changes in structural composition and content of functional groups on biochar surfaces. The artificial physical aging model was assessed as an efficient tool for investigation of natural weathering conditions.

  17. Lead toxicity to Lemna minor predicted using a metal speciation chemistry approach.

    Science.gov (United States)

    Antunes, Paula M C; Kreager, Nancy J

    2014-10-01

    In the present study, predictive measures for Pb toxicity and Lemna minor were developed from bioassays with 7 surface waters having varied chemistries (0.5-12.5 mg/L dissolved organic carbon, pH of 5.4-8.3, and water hardness of 8-266 mg/L CaCO3 ). As expected based on water quality, 10%, 20%, and 50% inhibitory concentration (IC10, IC20, and IC50, respectively) values expressed as percent net root elongation (%NRE) varied widely (e.g., IC20s ranging from 306 nM to >6920 nM total dissolved Pb), with unbounded values limited by Pb solubility. In considering chemical speciation, %NRE variability was better explained when both Pb hydroxides and the free lead ion were defined as bioavailable (i.e., f{OH} ) and colloidal Fe(III)(OH)3 precipitates were permitted to form and sorb metals (using FeOx as the binding phase). Although cause and effect could not be established because of covariance with alkalinity (p = 0.08), water hardness correlated strongly (r(2)  = 0.998, p minor and highlight the importance of chemical speciation in Pb-based risk assessments for aquatic macrophytes. PMID:25044009

  18. Effect of gley formation on leaching of radionuclides and toxic metals from soils

    International Nuclear Information System (INIS)

    Radionuclides and toxic metals, entering the soil as a result of technogenic contamination, are not uniformly distributed throughout the soil body, but preferentially fixed on so-called gel films. The gel films represent colloid formations consisting of primarily amorphous iron hydroxides, coordination polymers of mixed Ca,Fe,Al fulvates and humates, and amorphous silica fixed on the muddy aluminosilicate fraction (238U, 239,240Pu, 152Eu, 232Th, 60Co) and stable elements (Co, Eu) leached from soil samples directly correlates with that of iron, suggesting that under reducing conditions the drainage solution contains a mixture of iron, radionuclides, and microelements of nearly constant composition. This result is consistent with the existing views that radionuclides and microelements in soils are concentrated in the gel films. Furthermore, it reveal that in the investigated system solubilisation of the gel films is accompanied by a combined transfer of radionuclides and stable microelements to the aqueous phase. The most significant effect of leaching was observed for plutonium. (author)

  19. Bio-leaching of toxic metals from geothermal waste. A preliminary engineering analysis

    Energy Technology Data Exchange (ETDEWEB)

    Dobryn, D.G.; Brisson, A.L.; Lee, C.M.; Roll, S.M.

    1986-02-01

    The feasibility of a biological facility to treat geothermal sludge from a base case 50-MW double-flash geothermal power plant in the Imperial Valley, California was evaluated. The effect of sludge and nutrient concentration, agitation air bubbling and sterility on the rate of metal solubilization by the bacteria Thiobacillus thiooxidans and ferrooxidans was examined. All experiments were performed in batch flasks and monitored daily for bacterial growth. T. Thiooxidans leached 36% of the zinc in the sludge after 288 hr but leached little chromium. T. ferrooxidans removed 60% of the chromium in the sludge after 250 hr but did not leach zinc. Sludge to medium ratios of greater than 10% were toxic to the microorganisms studied. the experimental results were used to design a biological solid-waste treatment plant. The design basis used was 5 wt % sludge in the leaching vessel with a residence time of 10 days. The non-regulated waste resulting from the treatment plant could be used for land fill or construction materials. The total capital cost for the bio-leaching plant is $3.3 million with an annual operating cost of $690,000. The total cost of this plant is about 0.2 cents/kWh of electricity produced, which is essentially the same cost as hauling the solid waste to a hazardous disposal site. This cost accounts for about 5% of the cost of producing electricity from geothermal power (4 cent/kWh).

  20. Effects of Cr III and Pb on the bioaccumulation and toxicity of Cd in tropical periphyton communities: Implications of pulsed metal exposures

    International Nuclear Information System (INIS)

    Metal exposure pattern, timing, frequency, duration, recovery period, metal type and interactions, has obscured effects on periphyton communities in lotic systems. The objective of this study was to investigate the effects of intermittent exposures of Cr III and Pb on Cd toxicity and bioaccumulation in tropical periphyton communities. Natural periphyton communities were transferred to artificial stream chambers and exposed to metal mixtures at different pulse timing, duration, frequency and recovery periods. Chlorophyll a, dry mass and metal accumulation kinetics were recorded. Cr and Pb decrease the toxic effects of Cd on periphyton communities. Periphyton has high Cd, Cr and Pb accumulation capacity. Cr and Pb reduced the levels of Cd sequestrated by periphyton communities. The closer the frequency and duration of the pulse is to a continuous exposure, the greater the effects of the contaminant on periphyton growth and metal bioaccumulation. Light increased toxic and accumulative effects of metals on the periphyton community. - Highlights: ► We investigated toxicity effects of pulsed metal exposures on bioaccumulation and toxicity in periphyton. ► High frequency of short duration pulses has effects equal to long duration exposures. ► Important role of light in modulating metal toxicity on periphyton demonstrated. ► Factors other than magnitude and duration must be considered in water quality criteria. ► Accurate prediction of metal effects on biofilms requires data on effluent variability. - The study highlights the importance of pulse timing, frequency, duration, recovery period and chemical type on aquatic life.

  1. Human health risk assessment based on toxicity characteristic leaching procedure and simple bioaccessibility extraction test of toxic metals in urban street dust of Tianjin, China.

    Science.gov (United States)

    Yu, Binbin; Wang, Yu; Zhou, Qixing

    2014-01-01

    The potential ecological and human health risk related with urban street dust from urban areas of Tianjin, China was quantitatively analyzed using the method of toxicity characteristic leaching procedure (TCLP) and simple bioaccessibility extraction test (SBET). In the study, Hakason index, Nemerow index (P), the hazard index (HI) and the cancer risk index (RI) were calculated to assess the potential risk. The sequence of potential ecological risk based on Hakason index was arsenic (As) > cadmium (Cd) > lead (Pb) > copper (Cu) > chromium (Cr), in particular, As and Cd were regarded as high polluted metals. While the results of extraction of TCLP were assessed using P, the sequence was As > Pb > Cd > Cr > Cu, which mean that As and Pb should be low polluted, and Cd, Cr and Cu would barely not polluted. For human health, total carcinogenic risk for children and adults was 2.01 × 10(-3) and 1.05 × 10(-3), respectively. This could be considered to be intolerable in urban street dust exposure. The sequence in the hazard quotient (HQ) of each element was As > Cr > Pb > Cu > Cd. The HI value of these toxic metals in urban street dust for children and adults was 5.88 × 10(-1) and 2.80 × 10(-1), respectively. According to the characters of chemistry, mobility, and bioavailability of metals in urban street dust, we estimated the hazards on the environment and human health, which will help us to get more reasonable information for risk management of metals in urban environment. PMID:24651129

  2. Human health risk assessment based on toxicity characteristic leaching procedure and simple bioaccessibility extraction test of toxic metals in urban street dust of Tianjin, China.

    Directory of Open Access Journals (Sweden)

    Binbin Yu

    Full Text Available The potential ecological and human health risk related with urban street dust from urban areas of Tianjin, China was quantitatively analyzed using the method of toxicity characteristic leaching procedure (TCLP and simple bioaccessibility extraction test (SBET. In the study, Hakason index, Nemerow index (P, the hazard index (HI and the cancer risk index (RI were calculated to assess the potential risk. The sequence of potential ecological risk based on Hakason index was arsenic (As > cadmium (Cd > lead (Pb > copper (Cu > chromium (Cr, in particular, As and Cd were regarded as high polluted metals. While the results of extraction of TCLP were assessed using P, the sequence was As > Pb > Cd > Cr > Cu, which mean that As and Pb should be low polluted, and Cd, Cr and Cu would barely not polluted. For human health, total carcinogenic risk for children and adults was 2.01 × 10(-3 and 1.05 × 10(-3, respectively. This could be considered to be intolerable in urban street dust exposure. The sequence in the hazard quotient (HQ of each element was As > Cr > Pb > Cu > Cd. The HI value of these toxic metals in urban street dust for children and adults was 5.88 × 10(-1 and 2.80 × 10(-1, respectively. According to the characters of chemistry, mobility, and bioavailability of metals in urban street dust, we estimated the hazards on the environment and human health, which will help us to get more reasonable information for risk management of metals in urban environment.

  3. Bioavailability and toxicity of trace metals to the cladoceran Daphnia magna in relation to cadmium exposure history

    Science.gov (United States)

    Guan, Rui

    The cladoceran Daphnia magna is widely used in freshwater bioassessments and ecological risk assessments. This study designed a series of experiments employing radiotracer methodology to quantify the trace metals (mainly Cd and Zn) biokinetics in D. magna under different environmental and biological conditions and to investigate the influences of different Cd exposure histories on the bioavailability and toxicity of trace metals to D. magna. A bioenergetic-based kinetic model was finally applied in predicting the Cd accumulation dynamics in D. magna and the model validity under non-steady state was assessed. Cd assimilation was found in this study to be influenced by the food characteristics (e.g., metal concentration in food particles), the metal exposure history of the animals, and the genetic characteristics. Some of these influences could be interpreted by the capacity and/or competition of those metal binding sites within the digestive tract and/or the detoxifying proteins metallothionein (MT). My study demonstrated a significant induction of MT in response to Cd exposure and it was the dominant fraction in sequestering the internal nonessential trace metals in D. magna. The ratio of Cd body burden to MT might better predict the Cd toxicity on the digestion systems of D. magna than the Cd tissue burden alone within one-generational exposure to Cd. It was found that metal elimination (rate constant and contribution of different release routes) was independent of the food concentration and the dietary metal concentration, implying that the elimination may not be metabolically controlled. The incorporation of the bioenergetic-based kinetic model, especially under non-steady state, is invaluable in helping to understand the fate of trace metals in aquatic systems and potential environmental risks. The dependence of biokinetic parameters on environmental factors rather than on genotypes implies a great potential of using biokinetics in inter-laboratory comparisons.

  4. ACUTE TOXICITY OF METALS: NICKEL AND ZINC TO PARAMECIUM BURSARIA AND ITS ENDOSYMBIONTS

    Directory of Open Access Journals (Sweden)

    Patrycja Zagata

    2015-02-01

    Full Text Available Paramecium bursaria is an unicellular organism, widely distributed in the freshwater environment, where heavy metals are common contaminants. The ciliates, also including Paramecium bursaria, are a very abundant group in aquatic ecosystems, what makes them effective biological indicators of water pollutants. Paramecium bursaria is the only Paramecium which has evolved a mutualistic relationship with algae and it harbors these endosymbionts in its own cytoplasm. The algae are also very effective bioindicators of some pollutants because of their ability to biosorption and bioaccumulation of heavy metals. The aim of this study was to determine the acute toxicity of two metals’ compounds: nickel chloride (NiCl2 and zinc chloride (ZnCl2 to Paramecium bursaria and its endosymbionts. The ciliates were incubated in solutions with 5x10-8 to 5x10-2g/dm3 of NiCl2 and with 5x10-8 to 5x10-2g/dm3 of ZnCl2, at the temperature of 180C, in the light/dark conditions (12L/12D. Microscopic observations of cell divisions rate, cell shape changes as well as the swimming behavior, were conducted after 24, 48, 72 and 120 hours of incubation in the tested solutions and were compared to the control sample. Microscopic observations revealed the lethal doses for both compounds, for nickel chloride 5x10-5g/dm3 and for zinc chloride 5x10-3. These observations also revealed that in lesser concentrations than the lethal one, the slowdown and characteristic movements occur after metal addition. The PEA measurements of Fv/Fm parameter were carried out within 4 days, the first one after 24 hours of incubations. The results of this investigation has given us a view of a fluorescence efficiency by revealing that both compounds solutions can have the stimulating effect on Photosystem II, because the lowest fluorescence efficiency was measured in control samples.

  5. A new tropical algal test to assess the toxicity of metals in freshwaters. Supervising Scientists Report 133

    International Nuclear Information System (INIS)

    Copper (Cu) and uranium (U) are of potential ecotoxicological concern to tropical Australian freshwater biota as a result of mining impacts. No local data on the toxicity of these metals to tropical freshwater algae are currently available. The aim of this study was to develop a toxicity test for an Australian tropical freshwater alga that can be added to the suite of tests currently available for tropical freshwater invertebrates and fish. This toxicity test was used to investigate the toxicity of Cu and U to the alga Chlorella sp (new species) in a synthetic softwater and to specifically determine the effect of pH on metal toxicity over the range typically found in soft fresh surface waters in tropical northern Australia. A growth inhibition toxicity test was successfully developed for this alga, which was isolated from Kakadu National Park, Northern Territory, prior to conducting the toxicity testing. Key environmental parameters including light, temperature and nutrients were optimised to obtain acceptable algal growth rates over 72 hours. HEPES buffer (2 mM at pH 6.5) was found to be a suitable and practical option for pH control that could be incorporated in the test protocol for Chlorella sp. The results obtained in this study confirmed a lack of toxic effects by HEPES on the algae, as well as negligible complexation with both Cu and U. Adequate pH control (ie -1) than U (13 μg L-1), and more sensitive than other Australian tropical freshwater species, with an order of sensitivity: Alga ≥Crustacea > Cnidaria > Mollusca > Chordata. The toxicity of Cu and U was highly pH-dependent. Copper concentrations needed to inhibit growth by 50% (72 h EC50) increased from 1.5 to 35 μg Cu L-1 as the pH decreased from 6.5 to 5.7. The 72 h EC50 for U increased from 44 to 78 μg U L-1 over the same pH range. Decreased toxicity at pH 5.7 was due to lower concentrations of cell-bound and intracellular Cu and U compared to that at pH 6.5. These results are explained in

  6. Assessing the influence of compost and biochar amendments on the mobility and toxicity of metals and arsenic in a naturally contaminated mine soil

    International Nuclear Information System (INIS)

    Amending contaminated soils with organic wastes can influence trace element mobility and toxicity. Soluble concentrations of metals and arsenic were measured in pore water and aqueous soil extracts following the amendment of a heavily contaminated mine soil with compost and biochar (10% v:v) in a pot experiment. Speciation modelling and toxicity assays (Vibrio fischeri luminescence inhibition and Lolium perenne germination) were performed to discriminate mechanisms controlling metal mobility and assess toxicity risk thereafter. Biochar reduced free metal concentrations furthest but dissolved organic carbon primarily controlled metal mobility after compost amendment. Individually, both amendments induced considerable solubilisation of arsenic to pore water (>2500 μg l−1) related to pH and soluble phosphate but combining amendments most effectively reduced toxicity due to simultaneous reductions in extractable metals and increases in soluble nutrients (P). Thus the measure–monitor-model approach taken determined that combining the amendments was most effective at mitigating attendant toxicity risk. -- Highlights: • Compost and biochar addition to a mine soil decreased metal solubility. • Inorganic arsenic solubility was increased furthest by compost alone. • Combining amendments most effectively reduced toxicity, assessed by bio-assays. • Field study should verify the efficacy of the amendment in the longer term. -- Individual compost and biochar amendments to a contaminated mine soil decreased metal and increased arsenic solubility, but combining amendments most effectively reduced toxicity

  7. Assessing metal toxicity in sediments using the equilibrium partitioning model and empirical sediment quality guidelines: A case study in the nearshore zone of the Bohai Sea, China

    International Nuclear Information System (INIS)

    Highlights: • Based on the EqP model, 35% samples had potential metal toxicity in sediments. • The empirical SQGs are not suitable for assessing sediment toxicity in Bohai Sea. • The EqP model is a much needed tool for metal toxicity assessment in coastal China. - Abstract: Surface sediments were collected from five nearshore (wastewater discharges, aquaculture facilities and a seaport) sites in Bohai Bay and Laizhou Bay, China. The equilibrium partitioning (EqP) model and empirical sediment quality guidelines (SQGs) were applied to assess the potential metal toxicity in the collected sediments. The results show that, based on the EqP model, 35% of stations exhibited potential metal toxicity. Several metals (Cu, Ni and Cr) exceeded the empirical SQGs (9–93% of the time), however these guidelines may not be suitable for use in the Bohai Sea owing to the background concentrations. The EqP model is a more useful method for assessing potential metal toxicity in Bohai Sea sediment than the empirical SQGs. Additionally, we have provided new understanding about methods for assessing sediment metal toxicity in the Bohai Sea that may be useful in other coastal areas in China

  8. Evaluation of Toxic Metals and Essential Elements in Children with Learning Disabilities from a Rural Area of Southern Brazil

    Directory of Open Access Journals (Sweden)

    Sabrina Nunes do Nascimento

    2014-10-01

    Full Text Available Children’s exposure to metals can result in adverse effects such as cognitive function impairments. This study aimed to evaluate some toxic metals and levels of essential trace elements in blood, hair, and drinking water in children from a rural area of Southern Brazil. Cognitive ability and δ-aminolevulinate dehydratase (ALA-D activity were evaluated. Oxidative stress was evaluated as a main mechanism of metal toxicity, through the quantification of malondialdehyde (MDA levels. This study included 20 children from a rural area and 20 children from an urban area. Our findings demonstrated increase in blood lead (Pb levels (BLLs. Also, increased levels of nickel (Ni in blood and increase of aluminum (Al levels in hair and drinking water in rural children were found. Deficiency in selenium (Se levels was observed in rural children as well. Rural children with visual-motor immaturity presented Pb levels in hair significantly increased in relation to rural children without visual-motor immaturity (p < 0.05. Negative correlations between BLLs and ALA-D activity and positive correlations between BLLs and ALA-RE activity were observed. MDA was significantly higher in rural compared to urban children (p < 0.05. Our findings suggest that rural children were co-exposed to toxic metals, especially Al, Pb and Ni. Moreover, a slight deficiency of Se was observed. Low performance on cognitive ability tests and ALA-D inhibition can be related to metal exposure in rural children. Oxidative stress was suggested as a main toxicological mechanism involved in metal exposure.

  9. CCQM key comparison CCQM-K75: Determination of toxic metals in algae

    Science.gov (United States)

    Shakhashiro, A.; Toervenyi, A.; Gaudino, S.; Rosamilia, S.; Belli, M.; Turk, G. C.

    2011-01-01

    The determination of mass fraction of toxic elements and especially platinum emitted from automobile catalytic converters in the air is a critical factor in assessing air quality and the potential impact of possible pollutants. Air is in fact one of the main pathways for human exposure to toxic elements. Biomonitors, such as lichen and algae, are examples of environmental samples that have been widely used by the scientific community to assess and monitor the level of environmental pollution. For this purpose, the IAEA-450 algae material containing heavy metals and platinum at low level was prepared by IAEA Seibersdorf Laboratories in collaboration with the Italian National Institute for Environmental Protection—ISPRA (former APAT). During the April meeting in 2009 of the Inorganic Analysis Working Group (IAWG) of the CCQM it was agreed to organize a key comparison K75 for Pt and Ni and a parallel pilot study P118 for As, Cd, Cr, Hg, Ni, Pb and Pt using this algae material. The key comparison CCQM-K75 was successfully organized. The participating NMIs demonstrated a high level of measurement capabilities and technical competence in analysing nickel and platinum at a low level of concentration in environmental samples such as algae. The between-laboratories reproducibility standard deviation for nickel and platinum was 1.9% and 3.6% respectively, which reflects an excellent agreement of between-laboratories measurement results. The ratio between the bias and its expanded uncertainty for nickel and platinum was below 2.0 for all reported results except in one case. This study was a practical demonstration of a CCQM comparison to use the 'core-capabilities' utilized by participants as a mean of providing evidence for Calibration and Measurement Capabilities (CMC) claims for Ni and Pt. Based on this CCQM international key comparison, the measurement capability of the NMIs which participated in the CCQM-K75 has been demonstrated directly for determination of Pt and Ni

  10. Layered Double Hydroxides as Effective Adsorbents for U(VI) and Toxic Heavy Metals Removal from Aqueous Media

    OpenAIRE

    G. N. Pshinko

    2013-01-01

    Capacities of different synthesized Zn,Al-hydrotalcite-like adsorbents, including the initial carbonate [Zn4Al2(OH)12]·CO3·8H2O and its forms intercalated with chelating agents (ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and hexamethylenediaminetetraacetic acid (HMDTA)) and heat-treated form Zn4Al2O7, to adsorb uranium(VI) and ions of toxic heavy metals have been compared. Metal sorption capacities of hydrotalcite-like adsorbents have been shown to corr...

  11. Comprehensive assessment of toxic metals in urban and suburban street deposited sediments (SDSs) in the biggest metropolitan area of China

    International Nuclear Information System (INIS)

    A set of toxic metals, i.e. As, Hg, Pb, Cd, Cu, Zn, Ni and Cr, in urban and suburban SDSs were investigated comparatively in the biggest metropolitan area of China, Shanghai. Results showed that all of the metals except As were accumulated greatly, much higher than background values. Geo-accumulation index indicated that metal contamination in urban SDSs was generally heavier than that in suburban SDSs. Potential ecological risk index demonstrated that overall risks caused by metals were considerable. Cd contributed 52% to the overall risk. Multivariate statistical analysis revealed that in urban SDSs, Zn, Ni, Cd, Pb, Cu and Cr were related to traffic and industry; coal combustion led to elevated levels of Hg; soil parent materials controlled As contents. In suburban SDSs, Pb, Cu, As and Cd largely originated from traffic pollution; Zn, Ni and Cr were associated with industrial contaminants; Hg was mainly from domestic solid waste. - Sources and contamination characteristics of toxic metals in urban and suburban SDSs were different due to the varied levels of human activity intensity.

  12. Gas Exchange, Chlorophyll Fluorescence and Antioxidants as Bioindicators of Airborne Heavy Metal Pollution in Jeddah, Saudi Arabia

    OpenAIRE

    Hassan, I. A.; J.M. Basahi; I.M. Ismail

    2013-01-01

    Lettuce (Lactuca sativa L. cv. Romaine) plants were exposed to different levels of urbanization in Jeddah city, Saudi Arabia. They showed different degrees of visible injury symptoms and dramatic changes in enzymatic activities as well as net photosynthetic rates (PN), variable to maximum chlorophyll fluorescence (Fv/Fm) and stomatal conductance (gs).Visual symptoms of phytotoxicity of heavy metals were observed on plants grown at industrial and urban areas, where the concentrations of metals...

  13. A sensitive whole-cell biosensor for the simultaneous detection of a broad-spectrum of toxic heavy metal ions.

    Science.gov (United States)

    Cerminati, S; Soncini, F C; Checa, S K

    2015-04-01

    Bacterial biosensors are simple, cost-effective and efficient analytical tools for detecting bioavailable heavy metals in the environment. This work presents the design, construction and calibration of a novel whole-cell fluorescent biosensory device that, simultaneously and with high sensitivity, reports the presence of toxic mercury, lead, cadmium and/or gold ions in aqueous samples. This bio-reporter can be easily applied as an immediate alerting tool for detecting the presence of harmful pollutants in drinking water. PMID:25730473

  14. IMPACT OF HEAVY METAL AND OTHERS POLLUTANTS ON HEALTH AND ROLE OF THE PLANT IN TOXIC REMEDIATION

    OpenAIRE

    Preeti Sonkar* and Vinit Kumar

    2013-01-01

    An increased uptake of toxic metals by food crops grown on such soils together with human health risks are often recorded. Environmental pollution affects the quality of pedosphere, hydrosphere, atmosphere, lithosphere and biosphere. Great efforts have been made in the last two decades to reduce pollution sources and remedy the polluted soil and water resources. Phytoremediation, being more cost-effective and fewer side effects than physical and chemical approaches, has gained increasing popu...

  15. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Jost O.L. Wendt

    2001-05-04

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NO{sub x} concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. To this end we shall use an existing 17kW downflow laboratory combustor, available with coal and sludge feed capabilities. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NO{sub x} and low NO{sub x} combustion conditions will be investigated (unstaged and staged combustion). The proposed work uses existing analytical and experimental facilities and draws on 20 years of research on NO{sub x} and fine particles that has been funded by DOE in this laboratory. Four barrels of dried sewage sludge are currently in the laboratory. Insofar as possible pertinent mechanisms will be elucidated. Tradeoffs between CO{sub 2} control, NO{sub x} control, and inorganic fine particle and toxic metal emissions will be determined.

  16. Estimating genetic potential of biofuel forest hardwoods to withstand metal toxicity in industrial effluent under dry tropical conditions.

    Science.gov (United States)

    Manzoor, S A; Mirza, S N; Zubair, M; Nouman, W; Hussain, S B; Mehmood, S; Irshad, A; Sarwar, N; Ammar, A; Iqbal, M F; Asim, A; Chattha, M U; Chattha, M B; Zafar, A; Abid, R

    2015-01-01

    Biofuel tree species are recognized as a promising alternative source of fuel to conventional forms. Additionally, these tree species are also effective in accumulating toxic heavy metals present in some industrial effluents. In developing countries such as Pakistan, the use of biofuel tree species is gaining popularity not only for harvesting economical and environmentally friendly biofuel, but also to sequester poisonous heavy metals from industrial wastewater. This study was aimed at evaluating the genetic potential of two biofuel species, namely, Jatropha curcas and Pongamia pinnata, to grow when irrigated with industrial effluent from the Pak-Arab Fertilizer Factory Multan, Southern Punjab, Pakistan. The growth performances of one-year-old seedlings of both species were compared in soil with adverse physiochemical properties. It was found that J. curcas was better able to withstand the toxicity of the heavy metals present in the fertilizer factory effluent. J. curcas showed maximum gain in height, diameter, and biomass production in soil irrigated with 75% concentrated industrial effluent. In contrast, P. pinnata showed a significant reduction in growth in soil irrigated with more than 50% concentrated industrial effluent, indicating that this species is less tolerant to higher toxicity levels of industrial effluent. This study identifies J. curcas as a promising biofuel tree species that can be grown using industrial wastewater. PMID:26345887

  17. Toxicity assessment of heavy metals and organic compounds using CellSense biosensor with E.coli

    Institute of Scientific and Technical Information of China (English)

    Hong Wang; Xue Jiang Wang; Jian Fu Zhao; Ling Chen

    2008-01-01

    A new strategy using an amperometric biosensor with Escherichia coli(E.coli)that provides a rapid toxicity determination of chemical compounds is described.The CellSense biosensor system comprises a biological component immobilized in intimate contact with a transducer which converts the biochemical signal into a quantifiable electrical signal.Toxicity assessment of heavy metals using E.coli biosensors could be finished within 30 min and the 50% effective concentrations(EC50)values of four heavy metals were determined.The results shows that inhibitory effects of four heavy metals to E.coli can be ranked in a decreasing order of Hg2+>Cu2+>Zn2+>Ni2+,which accords to the results of conventional bacterial counting method.The toxicity test of organic compounds by using CellSense biosensor was also demonstrated.The CellSense biosensor with E.coli shows a good,reproducible behavior and can be used for reproducible measurements.

  18. Local impacts of coal mines and power plants across Canada. II. Metals, organics and toxicity in sediments

    Energy Technology Data Exchange (ETDEWEB)

    Cheam, V.; Reynoldson, T.; Garbai, G.; Rajkumar, J.; Milani, D. [Environment of Canada, Burlington, ON (Canada). National Water Research Institute

    2000-07-01

    A Canada-wide survey was undertaken to study local impacts of coal mines and coal-fired electrical generating stations. The first part dealt with thallium in waters and sediments. This, Part II, deals with metals and organics in sediments as well as sediment toxicity to four different organisms. Several elevated metal and PAH concentrations as well as high toxicity (based on biological sediment guidelines) were observed compared to uncontaminated sites. Based on Ontario's sediment guidelines, most of the studied sediments fell in the 'marginally to significantly polluted' category of sediment quality, although two belonged to the 'grossly polluted' class due to the extremely high concentrations of some metals. The observed diversity of PAHs and near-unity carbon preference indices indicate non-biological origins of the studied sediments. In this initial study, four different organisms, Chironomus riparius, Hyalella azteca, Hexagenia spp. (Hexagenia limbata) and Tubifex tubifex were used to determine sediment toxicity, which showed 50% of the tested sites were highly stressed.

  19. Influence of dissolved organic matter on photogenerated reactive oxygen species and metal-oxide nanoparticle toxicity.

    Science.gov (United States)

    Li, Yang; Niu, Junfeng; Shang, Enxiang; Crittenden, John Charles

    2016-07-01

    The effect of humic acid (HA) or fulvic acid (FA) on reactive oxygen species (ROS) generation by six metal-oxide nanoparticles (NPs) and their toxicities toward Escherichia coli was investigated under UV irradiation. Dissolved organic matter (DOM) decreased OH generation by TiO2, ZnO, and Fe2O3, with FA inhibiting OH generation more than HA. The generated OH in NPs/DOM mixtures was higher than the measured concentrations because DOM consumes OH faster than its molecular probe. None of NPs/FA mixtures produced O2(-). The generated O2(-) concentrations in NPs/HA mixtures (except Fe2O3/HA) were higher than the sum of O2(-) concentrations that produced as NPs and HA were presented by themselves. Synergistic O2(-) generation in NPs/HA mixtures resulted from O2 reduction by electron transferred from photoionized HA to NPs. DOM increased (1)O2 generation by TiO2, CuO, CeO2, and SiO2, and FA promoted (1)O2 generation more than HA. Enhanced (1)O2 generation resulted from DOM sensitization of NPs. HA did not increase (1)O2 generation by ZnO and Fe2O3 primarily because released ions quenched (1)O2 precursor ((3)HA*). Linear correlation was developed between total ROS concentrations generated by NPs/DOM mixtures and bacterial survival rates (R(2) ≥ 0.80). The results implied the necessity of considering DOM when investigating the photoreactivity of NPs. PMID:27064207

  20. Toxicity and the fractional distribution of trace metals accumulated from contaminated sediments by the clam Scrobicularia plana exposed in the laboratory and the field

    Energy Technology Data Exchange (ETDEWEB)

    Kalman, J., E-mail: judit.kalman@uca.es [Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Bonnail-Miguel, E. [Department of Physical-Chemistry, University of Cadiz, Poligono Industrial Rio San Pedro s/n, 11,510 Puerto Real, Cadiz (Spain); Smith, B.D. [Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Bury, N.R. [Division of Diabetes and Nutritional Science, King' s College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH (United Kingdom); Rainbow, P.S. [Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom)

    2015-02-15

    The relationship between the subcellular distribution of accumulated toxic metals into five operational fractions (subsequently combined into presumed detoxified and non-detoxified components) and toxicity in the clam Scrobicularia plana was investigated under different laboratory exposures. Clams were exposed to metal contaminated media (water and diet) and analysed for the partitioning of accumulated As, Cu and Zn into subcellular fractions. In general, metallothionein-like proteins, metal-rich granules and cellular debris in different proportions acted as main storage sites of accumulated metals in the clam soft tissues for these three metals. No significant differences were noted in the accumulation rates of As, Cu and Zn of groups of individuals with or without apparent signs of toxicity after up to 30 days of exposure to naturally contaminated sediment mixtures. There was, however, an increased proportional accumulation of Cu in the non-detoxified fraction with increased Cu accumulation rate in the clams, suggesting that the Cu uptake rate from contaminated sediments exceeded the combined rates of elimination and detoxification of Cu, with the subsequent likelihood for toxic effects in the clams. - Highlights: • Scrobicularia plana accumulated As, Cu and Zn from naturally toxic sediments. • Toxic metals were accumulated in detoxified and non-detoxified components. • Cu accumulation in the non-detoxified pool increased with increased Cu uptake rate. • Cu uptake rate exceeded combined loss and detoxification rates to cause toxicity.

  1. Toxicity and the fractional distribution of trace metals accumulated from contaminated sediments by the clam Scrobicularia plana exposed in the laboratory and the field

    International Nuclear Information System (INIS)

    The relationship between the subcellular distribution of accumulated toxic metals into five operational fractions (subsequently combined into presumed detoxified and non-detoxified components) and toxicity in the clam Scrobicularia plana was investigated under different laboratory exposures. Clams were exposed to metal contaminated media (water and diet) and analysed for the partitioning of accumulated As, Cu and Zn into subcellular fractions. In general, metallothionein-like proteins, metal-rich granules and cellular debris in different proportions acted as main storage sites of accumulated metals in the clam soft tissues for these three metals. No significant differences were noted in the accumulation rates of As, Cu and Zn of groups of individuals with or without apparent signs of toxicity after up to 30 days of exposure to naturally contaminated sediment mixtures. There was, however, an increased proportional accumulation of Cu in the non-detoxified fraction with increased Cu accumulation rate in the clams, suggesting that the Cu uptake rate from contaminated sediments exceeded the combined rates of elimination and detoxification of Cu, with the subsequent likelihood for toxic effects in the clams. - Highlights: • Scrobicularia plana accumulated As, Cu and Zn from naturally toxic sediments. • Toxic metals were accumulated in detoxified and non-detoxified components. • Cu accumulation in the non-detoxified pool increased with increased Cu uptake rate. • Cu uptake rate exceeded combined loss and detoxification rates to cause toxicity

  2. Toxicity of binary mixtures of metals and pyrethroid insecticides to Daphnia magna Straus. Implications for multi-substance risks assessment.

    Science.gov (United States)

    Barata, Carlos; Baird, D J; Nogueira, A J A; Soares, A M V M; Riva, M C

    2006-06-10

    Two different concepts, termed concentration addition (CA) and independent action (IA), describe general relationships between the effects of single substances and their corresponding mixtures allowing calculation of an expected mixture toxicity on the basis of known toxicities of the mixture components. Both concepts are limited to cases in which all substances in a mixture influence the same experimental endpoint, and are usually tested against a "fixed ratio design" where the mixture ratio is kept constant throughout the studies and the overall concentration of the mixture is systematically varied. With this design, interaction among toxic components across different mixture ratios and endpoints (i.e. lethal versus sublethal) is not assessed. In this study lethal and sublethal (feeding) responses of Daphnia magna individuals to single and binary combinations of similarly and dissimilarly acting chemicals including the metals (cadmium, copper) and the pyrethroid insecticides (lambda-cyhalothrin and deltamethrin) were assayed using a composite experimental design to test for interactions among toxic components across mixture effect levels, mixture ratios, lethal and sublethal toxic effects. To account for inter-experiment response variability, in each binary mixture toxicity assay the toxicity of the individual mixture constituents was also assessed. Model adequacy was then evaluated comparing the slopes and elevations of predicted versus observed mixture toxicity curves with those estimated for the individual components. Model predictive abilities changed across endpoints. The IA concept was able to predict accurately mixture toxicities of dissimilarly acting chemicals for lethal responses, whereas the CA concept did so in three out of four pairings for feeding response, irrespective of the chemical mode of action. Interaction effects across mixture effect levels, evidenced by crossing slopes, were only observed for the binary mixture Cd and Cu for lethal effects

  3. Toxicity of binary mixtures of metals and pyrethroid insecticides to Daphnia magna Straus. Implications for multi-substance risks assessment

    Energy Technology Data Exchange (ETDEWEB)

    Barata, Carlos [Laboratory of Environmental Toxicology, Universitat Poltiecnica de Catalunya, CN 150 Km 14.5, Terrassa 08220 (Spain)]. E-mail: barata@intexter.upc.edu; Baird, D.J. [National Water Research Institute (Environment Canada) at Canadian Rivers Institute, 10 Bailey Drive, PO Box 45111, University of New Brunswick, Fredericton E3B 6E1, New Brunswick (Canada); Nogueira, A.J.A. [Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Soares, A.M.V.M. [Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Riva, M.C. [Laboratory of Environmental Toxicology, Universitat Poltiecnica de Catalunya, CN 150 Km 14.5, Terrassa 08220 (Spain)

    2006-06-10

    Two different concepts, termed concentration addition (CA) and independent action (IA), describe general relationships between the effects of single substances and their corresponding mixtures allowing calculation of an expected mixture toxicity on the basis of known toxicities of the mixture components. Both concepts are limited to cases in which all substances in a mixture influence the same experimental endpoint, and are usually tested against a 'fixed ratio design' where the mixture ratio is kept constant throughout the studies and the overall concentration of the mixture is systematically varied. With this design, interaction among toxic components across different mixture ratios and endpoints (i.e. lethal versus sublethal) is not assessed. In this study lethal and sublethal (feeding) responses of Daphnia magna individuals to single and binary combinations of similarly and dissimilarly acting chemicals including the metals (cadmium, copper) and the pyrethroid insecticides ({lambda}-cyhalothrin and deltamethrin) were assayed using a composite experimental design to test for interactions among toxic components across mixture effect levels, mixture ratios, lethal and sublethal toxic effects. To account for inter-experiment response variability, in each binary mixture toxicity assay the toxicity of the individual mixture constituents was also assessed. Model adequacy was then evaluated comparing the slopes and elevations of predicted versus observed mixture toxicity curves with those estimated for the individual components. Model predictive abilities changed across endpoints. The IA concept was able to predict accurately mixture toxicities of dissimilarly acting chemicals for lethal responses, whereas the CA concept did so in three out of four pairings for feeding response, irrespective of the chemical mode of action. Interaction effects across mixture effect levels, evidenced by crossing slopes, were only observed for the binary mixture Cd and Cu for

  4. Toxicity of binary mixtures of metals and pyrethroid insecticides to Daphnia magna Straus. Implications for multi-substance risks assessment

    International Nuclear Information System (INIS)

    Two different concepts, termed concentration addition (CA) and independent action (IA), describe general relationships between the effects of single substances and their corresponding mixtures allowing calculation of an expected mixture toxicity on the basis of known toxicities of the mixture components. Both concepts are limited to cases in which all substances in a mixture influence the same experimental endpoint, and are usually tested against a 'fixed ratio design' where the mixture ratio is kept constant throughout the studies and the overall concentration of the mixture is systematically varied. With this design, interaction among toxic components across different mixture ratios and endpoints (i.e. lethal versus sublethal) is not assessed. In this study lethal and sublethal (feeding) responses of Daphnia magna individuals to single and binary combinations of similarly and dissimilarly acting chemicals including the metals (cadmium, copper) and the pyrethroid insecticides (λ-cyhalothrin and deltamethrin) were assayed using a composite experimental design to test for interactions among toxic components across mixture effect levels, mixture ratios, lethal and sublethal toxic effects. To account for inter-experiment response variability, in each binary mixture toxicity assay the toxicity of the individual mixture constituents was also assessed. Model adequacy was then evaluated comparing the slopes and elevations of predicted versus observed mixture toxicity curves with those estimated for the individual components. Model predictive abilities changed across endpoints. The IA concept was able to predict accurately mixture toxicities of dissimilarly acting chemicals for lethal responses, whereas the CA concept did so in three out of four pairings for feeding response, irrespective of the chemical mode of action. Interaction effects across mixture effect levels, evidenced by crossing slopes, were only observed for the binary mixture Cd and Cu for lethal effects

  5. Heavy metals produce toxicity, oxidative stress and apoptosis in the marine teleost fish SAF-1 cell line.

    Science.gov (United States)

    Morcillo, Patricia; Esteban, María Á; Cuesta, Alberto

    2016-02-01

    The use of cell lines to test the toxicity of aquatic pollutants is a valuable alternative to fish bioassays. In this study, fibroblast SAF-1 cells from the marine gilthead seabream (Sparus aurata L.) were exposed for 24 h to the heavy metals Cd, Hg, MeHg (Methylmercury), As or Pb and the resulting cytotoxicity was assessed. Neutral red (NR), MTT-tetrazolio (MTT), crystal violet (CV) and lactate dehydrogenase (LDH) viability tests showed that SAF-1 cells exposed to the above heavy metals produced a dose-dependent reduction in the number of viable cells. Methylmercury showed the highest toxicity (EC50 = 0.01 mM) followed by As, Cd, Hg and Pb. NR was the most sensitive method followed by MTT, CV and LDH. SAF-1 cells incubated with each of the heavy metals also exhibited an increase in the production of reactive oxygen species and apoptosis cell death. Moreover, the corresponding gene expression profiles pointed to the induction of the metallothionein protective system, cellular and oxidative stress and apoptosis after heavy metal exposure for 24 h. This report describes and compares tools for evaluating the potential effects of marine contamination using the SAF-1 cell line. PMID:26363324

  6. Interference of nickel with copper and iron homeostasis contributes to metal toxicity symptoms in the nickel hyperaccumulator plant Alyssum inflatum.

    Science.gov (United States)

    Ghasemi, Rasoul; Ghaderian, S Majid; Krämer, Ute

    2009-11-01

    The divalent cations of several transition metal elements have similar chemical properties and, when present in excess, one metal can interfere with the homeostasis of another. To better understand the role of interactions between transition metals in the development of metal toxicity symptoms in plants, the effects of exposure to excess nickel (Ni) on copper (Cu) and iron (Fe) homeostasis in the Ni hyperaccumulator plant Alyssum inflatum were examined. Alyssum inflatum was hypertolerant to Ni, but not to Cu. Exposure to elevated subtoxic Ni concentrations increased Cu sensitivity, associated with enhanced Cu accumulation and enhanced root surface Cu(II)-specific reductase activity. Exposure to elevated Ni concentrations resulted in an inhibition of root-to-shoot translocation of Fe and concentration-dependent progressive Fe accumulation in root pericycle, endodermis and cortex cells of the differentiation zone. Shoot Fe concentrations, chlorophyll concentrations and Fe-dependent antioxidant enzyme activities were decreased in Ni-exposed plants when compared with unexposed controls. Foliar Fe spraying or increased Fe supply to roots ameliorated the chlorosis observed under exposure to high Ni concentrations. These results suggest that Ni interferes with Cu regulation and that the disruption of root-to-shoot Fe translocation is a major cause of nickel toxicity symptoms in A. inflatum. PMID:19691676

  7. Effect of calcium on RNA content in meristematic cells of pea (Pisum sativum L.) roots treated with toxic metals.

    Science.gov (United States)

    Lbik-Nowak, A; Gabara, B

    1997-01-01

    RNA content in nucleolus, nucleus and cytoplasm in meristematic cells of pea roots growing for 144 h in the presence of calcium and/or toxic metals (Cd2+, Cr3+, Pb2+) was examined using cytophotometric procedures, after staining with gallocyanine. The effect of treatment with tested metals was twofold: on the one hand, it considerably reduced RNA content in the nucleolus, on the other it enhanced RNA level in the nucleus and most visibly in the cytoplasm, resulting in the increase in total amount of RNA in cells of pea roots. The presence of calcium in metal solutions in different ways affected RNA content in meristematic cells of pea. In roots treated with cadmium, the addition of calcium ions diminished the toxic effect of that metal, as demonstrated by an increase in RNA content in the nucleolus, although reduction of RNA amount in the nucleus, cytoplasm and in whole cell was observed. A clearly stimulative effect of calcium was noted in material grown in the presence of chromium or lead, where a high increase in RNA content in nucleolus, nucleus and cytoplasm took place. PMID:9619424

  8. Reevaluating the free-ion activity model of trace metal toxicity toward higher plants: experimental evidence with copper and zinc.

    Science.gov (United States)

    Parker, D R; Pedler, J F; Ahnstrom, Z A; Resketo, M

    2001-04-01

    Across a diverse spectrum of organisms, the absorption and toxicity of trace elements are usually correlated with the activity of the free metal ion, but reported exceptions to this generalization are increasing. For the first time, we tested the validity of the free-ion activity model (FIAM) in the case of terrestrial plants and organic acids that may be abundant in the soil solution and rhizosphere. Short-term (48-h) root elongation of wheat (Triticum aestitvum L.) in a simple medium (2 mM CaCl2, pH 6.0) was used to probe the toxicity of Cu and Zn in the presence of malonate, malate, and citrate. Precautions were taken to prevent biodegradation of the organic acids, and its absence was confirmed by ion chromatography. Copper speciation was verified using a Cu-selective ion electrode, and published stability constants were modified to improve agreement between measured and calculated Cu2+ activities. With additions of both malonate and malate, Cu toxicity was alleviated but not to the extent predicted by the FIAM; the Cu-ligand complexes seemingly contributed to the toxicity. No such departures were observed with citrate and Cu nor with any of the three ligands in combination with Zn. Thus, exceptions to the FIAM occur with higher plants as well as with aquatic biota but do not seem to occur in a predictable or systematic fashion with respect to metal or organic acid under investigation. Several possible explanations for the observed departures from the FIAM are discussed, including the possibility of accidental cotransport of metal and ligand into the cytoplasm. PMID:11345467

  9. Clioquinol promotes the degradation of metal-dependent amyloid-β (Aβ) oligomers to restore endocytosis and ameliorate Aβ toxicity.

    Science.gov (United States)

    Matlack, Kent E S; Tardiff, Daniel F; Narayan, Priyanka; Hamamichi, Shusei; Caldwell, Kim A; Caldwell, Guy A; Lindquist, Susan

    2014-03-18

    Alzheimer's disease (AD) is a common, progressive neurodegenerative disorder without effective disease-modifying therapies. The accumulation of amyloid-β peptide (Aβ) is associated with AD. However, identifying new compounds that antagonize the underlying cellular pathologies caused by Aβ has been hindered by a lack of cellular models amenable to high-throughput chemical screening. To address this gap, we use a robust and scalable yeast model of Aβ toxicity where the Aβ peptide transits through the secretory and endocytic compartments as it does in neurons. The pathogenic Aβ 1-42 peptide forms more oligomers and is more toxic than Aβ 1-40 and genome-wide genetic screens identified genes that are known risk factors for AD. Here, we report an unbiased screen of ∼140,000 compounds for rescue of Aβ toxicity. Of ∼30 hits, several were 8-hydroxyquinolines (8-OHQs). Clioquinol (CQ), an 8-OHQ previously reported to reduce Aβ burden, restore metal homeostasis, and improve cognition in mouse AD models, was also effective and rescued the toxicity of Aβ secreted from glutamatergic neurons in Caenorhabditis elegans. In yeast, CQ dramatically reduced Aβ peptide levels in a copper-dependent manner by increasing degradation, ultimately restoring endocytic function. This mirrored its effects on copper-dependent oligomer formation in vitro, which was also reversed by CQ. This unbiased screen indicates that copper-dependent Aβ oligomer formation contributes to Aβ toxicity within the secretory/endosomal pathways where it can be targeted with selective metal binding compounds. Establishing the ability of the Aβ yeast model to identify disease-relevant compounds supports its further exploitation as a validated early discovery platform. PMID:24591589

  10. Content of toxic and essential metals in medicinal herbs growing in polluted and unpolluted areas of Macedonia.

    Science.gov (United States)

    Gjorgieva, Darinka; Kadifkova-Panovska, Tatjana; Baceva, Katerina; Stafilov, Trajce

    2010-09-01

    The aim of this study was to determine and compare Ba, Cr, Cd, Fe, Sr, Pb, and Zn content in medicinal herbs Urtica dioica L., Taraxacum officinale, and Matricaria recutita growing in polluted and unpolluted areas of the Republic of Macedonia. The metal content was determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES). In the unpolluted area of Mt. Plackovica the metal content in Taraxacum officinale was in the descending order: Fe>Sr>Zn>Ba>Cr, while Pb and Cd were below the limit of detection. In the polluted area of Veles, the order was as follows: Fe>Zn>Sr>Pb>Ba>Cd>Cr. Our results suggest that quality assurance and monitoring of toxic metals is needed for plants intended for human use and consumption. Medicinal plants should be picked in areas free of any contamination sources. PMID:20860970

  11. Colorimetric sensor array based on gold nanoparticles and amino acids for identification of toxic metal ions in water.

    Science.gov (United States)

    Sener, Gulsu; Uzun, Lokman; Denizli, Adil

    2014-01-01

    A facile colorimetric sensor array for detection of multiple toxic heavy metal ions (Hg(2+), Cd(2+), Fe(3+), Pb(2+), Al(3+), Cu(2+), and Cr(3+)) in water is demonstrated using 11-mercaptoundecanoic acid (MUA)-capped gold nanoparticles (AuNPs) and five amino acids (lysine, cysteine, histidine, tyrosine, and arginine). The presence of amino acids (which have functional groups that can form complexes with metal ions and MUA) regulates the aggregation of MUA-capped particles; it can either enhance or diminish the particle aggregation. The combinatorial colorimetric response of all channels of the sensor array (i.e., color change in each of AuNP and amino acid couples) enables naked-eye discrimination of all of the metal ions tested in this study with excellent selectivity. PMID:25330256

  12. Treatment of heterogeneous mixed wastes: Enzyme degradation of cellulosic materials contaminated with hazardous organics and toxic and radioactive metals

    International Nuclear Information System (INIS)

    The redirection and downsizing of the US Department of Energy's nuclear weapons complex requires that many facilities be decontaminated and decommissioned (D and D). At Los Alamos National Laboratory, much of the low-level radioactive, mixed, and hazardous/chemical waste volume handled by waste management operations was produced by D and D and environmental restoration activities. A combination of technologies--air stripping and biodegradation of volatile organics, enzymatic digestion of cellulosics, and metal ion extraction--was effective in treating a radiologically contaminated heterogeneous paint-stripping waste. Treatment of VOCs using a modified bioreactor avoided radioactive contamination of byproduct biomass and inhibition of biodegradation by toxic metal ions in the waste. Cellulase digestion of bulk cellulose minimized the final solid waste volume by 80%. Moreover, the residue passed TCLP for RCRA metals. Hazardous metals and radioactivity in byproduct sugar solutions were removed using polymer filtration, which employs a combination of water-soluble chelating polymers and ultrafiltration to separate and concentrate metal contaminants. Polymer filtration was used to concentrate RCRA metals and radioactivity into <5% of the original wastewater volume. Permeate solutions had no detectable radioactivity and were below RCRA-allowable discharge limits for Pb and Cr

  13. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Jost O.L. Wendt

    2002-08-15

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NOx concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NOx and low NOx combustion conditions will be investigated (unstaged and staged combustion). Tradeoffs between CO2 control, NOx control, and inorganic fine particle and toxic metal emissions will be determined. Previous research has yielded data on trace metal partitioning for MSS by itself, with natural gas assist, for coal plus MSS combustion together, and for coal alone. We have re-evaluated the inhalation health effects of ash aerosol from combustion of MSS both by itself and also together with coal. We have concluded that ash from the co-combustion of MSS and coal is very much worse from an inhalation health point of view, than ash from either MSS by itself or coal by itself. The reason is that ZnO is not the ''bad actor'' as had been suspected before, but the culprit is, rather, sulfated Zn. The MSS supplies the Zn and the coal supplies the sulfur, and so it is the combination of coal and MSS that makes that process environmentally bad. If MSS is to be burned, it should be burned without coal, in the absence of sulfur.

  14. Occupational exposure to airborne nanomaterials: An assessment of worker exposure to aerosolized metal oxide nanoparticles in a semiconductor fab and subfab.

    Science.gov (United States)

    Brenner, Sara A; Neu-Baker, Nicole M; Caglayan, Cihan; Zurbenko, Igor G

    2016-09-01

    This occupational exposure assessment study characterized potential inhalation exposures of workers to engineered nanomaterials associated with chemical mechanical planarization wafer polishing processes in a semiconductor research and development facility. Air sampling methodology was designed to capture airborne metal oxide nanoparticles for characterization. The research team obtained air samples in the fab and subfab areas using a combination of filter-based capture methods to determine particle morphology and elemental composition and real-time direct-reading instruments to determine airborne particle counts. Filter-based samples were analyzed by electron microscopy and energy-dispersive x-ray spectroscopy while real-time particle counting data underwent statistical analysis. Sampling was conducted during worker tasks associated with preventive maintenance and quality control that were identified as having medium to high potential for inhalation exposure based on qualitative assessments. For each sampling event, data was collected for comparison between the background, task area, and personal breathing zone. Sampling conducted over nine months included five discrete sampling series events in coordination with on-site employees under real working conditions. The number of filter-based samples captured was: eight from worker personal breathing zones; seven from task areas; and five from backgrounds. A complementary suite of direct-reading instruments collected data for seven sample collection periods in the task area and six in the background. Engineered nanomaterials of interest (Si, Al, Ce) were identified in filter-based samples from all areas of collection, existing as agglomerates (>500 nm) and nanoparticles (100-500 nm). Particle counts showed an increase in number concentration above background during a subset of the job tasks, but particle counts in the task areas were otherwise not significantly higher than background. Additional data is needed to

  15. Brown algae overproduce cell wall polysaccharides as a protection mechanism against the heavy metal toxicity

    International Nuclear Information System (INIS)

    Brown algae are often used as heavy metal biomonitors and biosorbents because they can accumulate high concentrations of metals. Cation-exchange performed by cell wall polysaccharides is pointed out as the main chemical mechanism for the metal sequestration. Here, we biochemically investigated if the brown alga Padina gymnospora living in a heavy metal contaminated area would modify their polysaccharidic content. We exposed non-living biomass to Cd and Pb and studied the metals adsorption and localization. We found that raw dried polysaccharides, sulfate groups, uronic acids, fucose, mannose, and galactose were significantly higher in contaminated algae compared with the control ones. Metal concentrations adsorbed by non-living biomass were rising comparatively to the tested concentrations. Electron microscopy showed numerous granules in the cell walls and X-ray microanalysis revealed Cd as the main element. We concluded that P. gymnospora overproduces cell wall polysaccharides when exposed to high metal concentrations as a defense mechanism.

  16. Endophytes and their Potential to Deal with Co-contamination of Organic Contaminants (Toluene) and Toxic Metals (Nickel) during Phytoremediation

    Energy Technology Data Exchange (ETDEWEB)

    Weyens, N.; van der Lelie, D.; Truyens, S.; Saenen, E.; Boulet, J.; Dupae, J.; Taghavi, S.; Carleer, R.; Vangronsveld, J.

    2011-01-15

    The aim was to investigate if engineered endophytes that are capable of degrading organic contaminants, and deal with or ideally improve uptake and translocation of toxic metals, can improve phytoremediation of mixed organic-metal pollution. As a model system, yellow lupine was inoculated with the endophyte Burkholderia cepacia VM1468 possessing (a) the pTOM-Bu61 plasmid, coding for constitutive toluene/TCE degradation, and (b) the chromosomally inserted ncc-nre Ni resistance/sequestration system. As controls, plants were inoculated with B. vietnamiensis BU61 (pTOM-Bu61) and B. cepacia BU72 (containing the ncc-nre Ni resistance/sequestration system). Plants were exposed to mixes of toluene and Ni. Only inoculation with B. cepacia VM1468 resulted in decreased Ni and toluene phytotoxicity, as measured by a protective effect on plant growth and decreased activities of enzymes involved in antioxidative defence (catalase, guaiacol peroxidase, superoxide dismutase) in the roots. Besides, plants inoculated with B. cepacia VM1468 and B. vietnamiensis BU61 released less toluene through the leaves than non-inoculated plants and those inoculated with B. cepacia BU72. Ni-uptake in roots was slightly increased for B. cepacia BU72 inoculated plants. These results indicate that engineered endophytes have the potential to assist their host plant to deal with co-contamination of toxic metals and organic contaminants during phytoremediation.

  17. Sequential application of chelating agents and innovative surfactants for the enhanced electroremediation of real sediments from toxic metals and PAHs.

    Science.gov (United States)

    Hahladakis, John N; Lekkas, Nikolaos; Smponias, Andreas; Gidarakos, Evangelos

    2014-06-01

    This study focused on the sequential application of a chelating agent (citric acid) followed by a surfactant in the simultaneous electroremediation of real contaminated sediments from toxic metals and Polycyclic Aromatic Hydrocarbons (PAHs). Furthermore, the efficiency evaluation of two innovative non-ionic surfactants, commercially known as Poloxamer 407 and Nonidet P40, was investigated. The results indicated a removal efficacy of approximately 43% and 48% for the summation of PAHs (SUM PAHs), respectively for the aforementioned surfactants, much better than the one obtained by the use of Tween 80 (nearly 21%). Individual PAHs (e.g. fluorene) were removed in percentages that reached almost 84% and 92% in the respective electrokinetic experiments when these new surfactants were introduced. In addition, the combined-enhanced sequential electrokinetic treatment with citric acid improved dramatically the removal of Zn and As, compared to the unenhanced run, but did not favor the other toxic metals examined. Since no improvement in metal removal percentages occurred when Tween 80 was used, significant contribution to this matter should also be attributed to the solubilization capacity of these innovative, in electrokinetic remediation, non-ionic surfactants. PMID:24321329

  18. Comparison of three-stage sequential extraction and toxicity characteristic leaching tests to evaluate metal mobility in mining wastes

    International Nuclear Information System (INIS)

    Abandoned mining sites contain residues from ore processing operations that are characterised by high concentrations of heavy metals. The form in which a metal exists strongly influences its mobility and, thus, the effects on the environment. Operational methods of speciation analysis, such as the use of sequential extraction procedures, are commonly applied. In this work, the modified three-stage sequential extraction procedure proposed by the BCR (now the Standards, Measurements and Testing Programme) was applied for the fractionation of Ni, Zn, Pb and Cd in mining wastes from old Pb-Zn mining areas located in the Val d'Aran (NE Spain) and Cartagena (SE Spain). Analyses of the extracts were performed by inductively coupled plasma atomic emission spectrometry and electrothermal atomic absorption spectrometry. The procedure was evaluated by using a certified reference material, BCR-701. The results of the partitioning study indicate that more easily mobilised forms (acid exchangeable) were predominant for Cd and Zn, particularly in the sample from Cartagena. In contrast, the largest amount of lead was associated with the iron and manganese oxide fractions. On the other hand, the applicability of lixiviation tests commonly used to evaluate the leaching of toxic species from landfill disposal (US-EPA Toxicity Characteristic Leaching Procedure and DIN 38414-S4) to mining wastes was also investigated and the obtained results compared with the information on metal mobility derivable from the application of the three-stage sequential extraction procedure

  19. FRAGMENTATION OF POLYTENE CHROMOSOMES OF CHIRONOMUS STRIATIPENNIS (KIEFFER AS A MARK OF HEAVY METAL TOXICITY IN AQUATIC HABITATS

    Directory of Open Access Journals (Sweden)

    A. MAZUMDAR

    2013-01-01

    Full Text Available The adults of Chironomids are though terrestrial, but in immature stages they pass their days in water. In aquaticbodies the flies at their larval stages live about 18-20 days and any incompatible situation in the habitats affectsgrowth and development of the larvae. A study on the polytene chromosomes of the salivary gland cells of thelarvae of C. striatipennis indicated that high level of toxicity due to heavy metals in the habitats led to fragmentationof their polytene chromosomes. Culturing of the larvae of this species in the laboratory with 30 mg/Kg of Cd withsoil in the culture bed exhibited fragmentation of their polytene chromosomes in certain cases. In this toxicityimpact the fourth polytene chromosome appeared to be more affected. Hence, a variation of response of differentchromosomes of the fly to toxicity may be suggested.

  20. NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Jost O.L. Wendt

    2002-02-05

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NO{sub x} concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. To this end work is progress using an existing 17kW downflow laboratory combustor, available with coal and sludge feed capabilities. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NO{sub x} and low NO{sub x} combustion conditions will be investigated (unstaged and staged combustion). The proposed work uses existing analytical and experimental facilities and draws on 20 years of research on NO{sub x} and fine particles that has been funded by DOE in this laboratory. Four barrels of dried sewage sludge are currently in the laboratory. Insofar as possible pertinent mechanisms will be elucidated. Tradeoffs between CO{sub 2} control, NO{sub x} control, and inorganic fine particle and toxic metal emissions will be determined. Progress in the Sixth Quarter (January 1, 2002 through March 31, 2002) was slow because of slagging problems in the combustor. These required the combustor to be rebuilt, a job that is not yet complete. A paper describing our results heretofore has been accepted by the Journal Environmental Science and Technology.

  1. Adsorption of Toxic Metals and Control of Mosquitos-borne Disease by Lysinibacillus sphaericus:Dual Benefits for Health and Environment

    Institute of Scientific and Technical Information of China (English)

    Javier Edo.Vargas; Jenny Dussán

    2016-01-01

    Objective Assessment of the bacteriumL. sphaericusas a dual-action candidate for biological control of mosquito-borne diseases and bioremediation of toxic metals. Methods Larvae of the mosquito,C. quinquefasciatus, were first evaluated for metal tolerance and then exposed to 5 ppm cadmium, chromium, arsenic, and lead in assays together with seven strains of L. sphaericus. A probit regression analysis was used to estimate the LC50 of Cd, Cr, As, and Pb toC. quinquefasciatus.An analysis of covariance and multifactorial ANOVA examined the metal biosorption and larvicidal properties of the seven strains of L. sphaericus. Results We found that L. sphaericus adsorbed the toxic metal ions and was toxic against mosquito larvae. The L. sphaericus strain Ⅲ(3)7 resulted in a larvae mortality of over 80% for all the tested metals. This strain also exhibited the capacity to adsorb 76% of arsenic, 32% of lead, 25% of chromium, and 7%of cadmium. Conclusion This study found combined metal adsorption and larval toxicity associated with three strains ofL. sphaericus[Ⅲ(3)7, OT4b.31, and CBAM5]. This suggests that a combination of these strains shows strong dual potential forbiological control of mosquitosin heavy metal-contaminated areas and remediate the heavy metal contamination as well.

  2. Evaluation of the Possible Sources and Controlling Factors of Toxic Metals/Metalloids in the Florida Everglades and Their Potential Risk of Exposure.

    Science.gov (United States)

    Li, Yanbin; Duan, Zhiwei; Liu, Guangliang; Kalla, Peter; Scheidt, Daniel; Cai, Yong

    2015-08-18

    The Florida Everglades is an environmentally sensitive wetland ecosystem with a number of threatened and endangered fauna species susceptible to the deterioration of water quality. Several potential toxic metal sources exist in the Everglades, including farming, atmospheric deposition, and human activities in urban areas, causing concerns of potential metal exposure risks. However, little is known about the pollution status of toxic metals/metalloids of potential concern, except for Hg. In this study, eight toxic metals/metalloids (Cd, Cr, Pb, Ni, Cu, Zn, As, and Hg) in Everglades soils were investigated in both dry and wet seasons. Pb, Cr, As, Cu, Cd, and Ni were identified to be above Florida SQGs (sediment quality guidelines) at a number of sampling sites, particularly Pb, which had a level of potential risk to organisms similar to that of Hg. In addition, a method was developed for quantitative source identification and controlling factor elucidation of toxic metals/metalloids by introducing an index, enrichment factor (EF), in the conventional multiple regression analysis. EFs represent the effects of anthropogenic sources on metals/metalloids in soils. Multiple regression analysis showed that Cr and Ni were mainly controlled by anthropogenic loading, whereas soil characteristics, in particular natural organic matter (NOM), played a more important role for Hg, As, Cd, and Zn. NOM may control the distribution of these toxic metals/metalloids by affecting their mobility in soils. For Cu and Pb, the effects of EFs and environmental factors are comparable, suggesting combined effects of loading and soil characteristics. This study is the first comprehensive research with a vast amount of sampling sites on the distribution and potential risks of toxic metals/metalloids in the Everglades. The finding suggests that in addition to Hg other metals/metalloids could also potentially be an environmental problem in this wetland ecosystem. PMID:26197026

  3. DETERMINATION OF MOBILITY AND BIOAVAILABILITY OF HEAVY METALS IN THE URBAN AIR PARTICULATES MATTER OF ISFAHAN

    OpenAIRE

    Kalantari, A.; M. Talebi; B BINA

    2001-01-01

    Introduction: In addition to, Carbohyrates, Lipids, Amino acids and vitamins, some of the trace metals are known vital for biological activity. But some of them not only are not necessary, but also they are very toxic and carcinogen. In this research the rate of Mobility and Bioavailability of heavy metals associated with airborne particulates matter such as Zn, Pb, Cd, Cu, Fe, Ni and Cr have been measured. Methods: The sequential extraction has been used for releasing of heavy metales f...

  4. Evaluation of effect of galvanic corrosion between nickel-chromium metal and titanium on ion release and cell toxicity

    OpenAIRE

    Lee, Jung-Jin; Song, Kwang-Yeob; Ahn, Seung-Geun; Choi, Jung-Yun; Seo, Jae-Min; Park, Ju-Mi

    2015-01-01

    PURPOSE The purpose of this study was to evaluate cell toxicity due to ion release caused by galvanic corrosion as a result of contact between base metal and titanium. MATERIALS AND METHODS It was hypothesized that Nickel (Ni)-Chromium (Cr) alloys with different compositions possess different corrosion resistances when contacted with titanium abutment, and therefore in this study, specimens (10×10×1.5 mm) were fabricated using commercial pure titanium and 3 different types of Ni-Cr alloys (T3...

  5. Impact of heavy metal toxicity and constructed wetland system as a tool in remediation.

    Science.gov (United States)

    Usharani, B; Vasudevan, N

    2016-01-01

    The objective of this review is to throw light upon the global concern of heavy metal-contaminated sites and their remediation through an ecofriendly approach. Accumulated heavy metals in soil and water bodies gain entry through the food chain and pose serious threat to all forms of life. This has engendered interest in phytoremediation techniques where hyperaccumulators are used. Constructed wetland has a pivotal role and is a cost-effective technique in the remediation of heavy metals. Metal availability and mobility are influenced by the addition of chelating agents, which enhance the availability of metal uptake. This review helps in identifying the critical knowledge gaps and areas to enhance research in the future to develop strategies such as genetically engineered hyperaccumulators to attain an environment devoid of heavy metal contamination. PMID:25454352

  6. Quantitative analysis and reduction of the eco-toxicity risk of heavy metals for the fine fraction of automobile shredder residue (ASR) using H2O2.

    Science.gov (United States)

    Singh, Jiwan; Yang, Jae-Kyu; Chang, Yoon-Young

    2016-02-01

    Automobile shredder residue (ASR) fraction (size sequential extraction procedure has also been used to determine the heavy metal speciation in the fine fraction of ASR before and after treatment. A risk analysis of the fine fraction of ASR before and after treatment was conducted to assess the bioavailability and eco-toxicity of heavy metals. These results showed that the recovery of heavy metals from ASR increased with an increase in the hydrogen peroxide concentration. A high concentration of heavy metals was found to be present in Cbio fractions (the sum of the exchangeable and carbonate fractions) in the fine fraction of ASR, indicating high toxicity risk. The Cbio rate of all selected heavy metals was found to range from 8.6% to 33.4% of the total metal content in the fine fraction of ASR. After treatment, Cbio was reduced to 0.3-3.3% of total metal upon a treatment with 2.0% hydrogen peroxide. On the basis of the risk assessment code (RAC), the environmental risk values for heavy metals in the fine fraction of ASR reflect high risk/medium risk. However, after treatment, the heavy metals would be categorized as low risk/no risk. The present study concludes that hydrogen peroxide combined with nitric acid is a promising treatment for the recovery and reduction of the eco-toxicity risk of heavy metals in ASR. PMID:26482807

  7. Enhanced Toxic Metal Accumulation in Engineered Bacterial Cells Expressing Arabidopsis thaliana Phytochelatin Synthase

    OpenAIRE

    Sauge-Merle, Sandrine; Cuiné, Stéphan; Carrier, Patrick; Lecomte-Pradines, Catherine; Luu, Doan-Trung; Peltier, Gilles

    2003-01-01

    Phytochelatins (PCs) are metal-binding cysteine-rich peptides, enzymatically synthesized in plants and yeasts from glutathione in response to heavy metal stress by PC synthase (EC 2.3.2.15). In an attempt to increase the ability of bacterial cells to accumulate heavy metals, the Arabidopsis thaliana gene encoding PC synthase (AtPCS) was expressed in Escherichia coli. A marked accumulation of PCs was observed in vivo together with a decrease in the glutathione cellular content. When bacterial ...

  8. The role of heavy metals and toxic materials in the physiological ecology of submersed macrophytes

    OpenAIRE

    Guilizzoni, Piero

    1991-01-01

    An overview of, and information from, a number of publications dealing with the availability, uptake rates and accumulation of metals (eg. Fe, Cu, Cr, Cd, Pb) and organic substrances (e.g. polychlorinated biphensyls (PCB) and pesticides) by submersed and floating macrophytes are provided. Differences in metal enrichment are reported to be dependent mainly on the plant species, the seasonal growth rate changes, the tissue age, and metal or compound type. A brief review of the possible sites of...

  9. Natural and active chemical remediation of toxic metals, organics, and radionuclides in the aquatic environment

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, G.; Pintauro, P.; O`Connor, S. [and others

    1996-05-02

    This project focuses on the chemical aspects of remediation, with the underlying theme that chemical remediation does occur naturally. Included are studies on the fate of heavy metal and organic contaminants discharged into aquatic environments; accurate assay metal contaminants partitioned into soils, water and tissue; development of novel polymeric membranes and microporous solids for the entrapment of heavy metals; and the development of hybrid chemo-enzymatic oxidative schemes for aromatics decontamination. 49 refs.

  10. Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops*

    OpenAIRE

    Islam, Ejaz ul; Yang, Xiao-e; He, Zhen-li; Mahmood, Qaisar

    2006-01-01

    Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely: inhalation and ingestion, ingestion being the main rou...

  11. Bioremediation of heavy metal toxicity from factory effluents by transconjugants bacteria.

    Science.gov (United States)

    El-Zahrani, Hind A; El-Saied, A I

    2011-12-01

    The presence of heavy metals in aquatic environments is known to cause severe damage to aquatic life, beside the fact that these metals kill microorganisms during biological treatment of wastewater with a consequent delay of the process of water purification. Most of the heavy metal salts are soluble in water and form aqueous solutions and consequently cannot be separated by ordinary physical means of separation. Five bacterial strains were used in this study. Bacterial strains were marking using 10 antibiotics and 7 heavy metals to be use as a selectable markes in conjugation process. Mating were performed using five bacterial strains. These strains were genetically marking in relation to their tolerance to the different antibiotics and heavy metals. All matings between bacterial strains were successes. The biosorption capacities for all heavy metals determined were higher for some metals than others. The transconjugants strain Tr5 resulted from mating between the parental bacterial strains (B-6bs X B-21) was more efficient in molybdenum uptake than all bacterial strains when supplementednutrient media wi th wastewater. Bacterial strains (B-21) appeared a good uptake of heavy metal ions (copper, cadmium, iron, cadmium and Lead) than other bacterial strains. This work highlights the potential of bacterial strains B-21 in uptake of heavy metals. The transconjugant strain Tr3 resulted from mating between parental bacterial strains (B-1584 X B-287) was more efficient in chromium uptake than all bacterial strains. PMID:22435157

  12. Evaluation of the toxicity of fluids employed in the metallic tool industrial machining using aquatic ecotoxicology

    International Nuclear Information System (INIS)

    Eco toxicological analyses have being used to monitor environmental samples, industrial effluents and complex substances. With the objective to analyze the toxicity of cutting fluids used in the machinery industry, acute toxicity test with species of three different trophic levels: Vibrio fischeri, Daphnia similis, Daphnia laevis e Danio rerio, were performing. The samples of fluids were analyzed by COD, phenol, pH, color, density and surfactants. The physical and chemical parameters are the according with the brazilian law, CONAMA 357 (D.O.U. 2005). The results of the toxicity tests showed that the cutting fluids have high toxicity to the organisms used in this study and the gamma radiation treatment was not efficient to decrease the matrix. The biodegradation in soil demonstrated be effective to the cutting fluids and the indigenous bacteria were identified and isolated to possible treatment of soils contaminated with these kinds of substances. The monitoring and management of residues of cutting fluids are necessary to preservation of aquatic live, in consequence of their high toxicity. (author)

  13. Molecular mechanisms of the epithelial transport of toxic metal ions, particularly mercury, cadmium, lead, arsenic, zinc, and copper. Comprehensive progress report, October 1, 1975--December 31, 1978

    International Nuclear Information System (INIS)

    Investigations were undertaken to elucidate the mode of transepithelial transport of potentially toxic metal ions across the gastrointestinal tract, with primary attention given to cadmium, zinc, and arsenic. In addition, the toxic effects of cadmium on the metabolism of vitamin D and calcium have been investigated in some detail. Several approaches have been taken, including studies on the localization of heavy metals in the intestinal mucosa, the effects of cadmium on various parameters of calcium metabolism, the modes of intestinal absorption of cadmium, arsenate, and zinc, and the interactions of heavy metals with each other and with calcium, phosphorus, and vitamin D. Details of these experiments are attached in the Comprehensive Progress Report

  14. Molecular mechanisms of the epithelial transport of toxic metal ions, particularly mercury, cadmium, lead, arsenic, zinc, and copper. Comprehensive progress report, October 1, 1975--December 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Wasserman, R. H.

    1978-10-01

    Investigations were undertaken to elucidate the mode of transepithelial transport of potentially toxic metal ions across the gastrointestinal tract, with primary attention given to cadmium, zinc, and arsenic. In addition, the toxic effects of cadmium on the metabolism of vitamin D and calcium have been investigated in some detail. Several approaches have been taken, including studies on the localization of heavy metals in the intestinal mucosa, the effects of cadmium on various parameters of calcium metabolism, the modes of intestinal absorption of cadmium, arsenate, and zinc, and the interactions of heavy metals with each other and with calcium, phosphorus, and vitamin D. Details of these experiments are attached in the Comprehensive Progress Report.

  15. Decontamination of aquatic vegetable leaves by removing trace toxic metals during pickling process with acetic acid solution.

    Science.gov (United States)

    Wu, Wenbiao; Yang, Yixing

    2011-01-01

    The heavy-metal content of aquatic plants is mainly dependent upon their ecological system. This study indicated that although the toxic heavy-metal contents could be above the recommended maximum levels depending upon their concentrations in growing water, they can be decontaminated by pickling with 5% acetic acid solution. Almost all Cd, Hg, Ba, or Sb and 99.5% Pb, 96.7% Ag, or 97.1% Al were removed from Water Spinach leaves by soaking in acetic acid solution. For Water-Shield leaves, almost all Cd, Hg, Pb, Ba, or Sb and 95.0% Ag or 96.1% Al were removed. For Watercress leaves, almost all Cd, Hg, Ba, or Sb and 99.0% Pb or 99.7% Ag were removed. For Water Hyacinth leaves, almost all Cd, Ba, or Sb and 99.0% Hg, 98.5% Pb, 95.0% Ag, or 98.7% Al were removed. PMID:21888602

  16. Influence of inorganic anions on metals release from oil sands coke and on toxicity of nickel and vanadium to Ceriodaphnia dubia.

    Science.gov (United States)

    Puttaswamy, Naveen; Liber, Karsten

    2012-02-01

    In a previous study it was shown that pH significantly influences the release of metals from oil sands coke, particularly Ni and V which were identified as the cause of coke leachate toxicity. Coke comes in contact with oil sands process water (OSPW) during its transport to and long term storage in reclamation landscapes. However, the influence of dominant inorganic anions present in OSPW (i.e. HCO(3)(-), Cl(-) and SO(4)(2-)) on metals release from coke and on speciation and toxicity of Ni and V, has not been characterized before. Coke was subjected to a 15-d batch leaching process at four levels of HCO(3)(-), Cl(-) and SO(4)(2-) to determine the influence on metals release and speciation. Further, the effects of each of the three anions on Ni and V toxicity, as well as the mixture toxicity of Ni and V, were assessed using the three-brood Ceriodaphnia dubia test. Inorganic anions had a significant influence on the type and amount of metals released from coke. Specifically, sulfate increased the mobilization of cationic metals (e.g. Ni, Fe, Mn and Zn), whereas bicarbonate enhanced the release of oxyanion forming metals (e.g. Al, As, Mo and V) from coke. Chloride had no particular effect on the type and amount of metals released. With respect to toxicity, elevated bicarbonate levels decreased the 7-d Ni IC50 from 6.3 to 2.3 μg L(-1), whereas sulfate showed an ameliorative effect against V toxicity to C. dubia. In combination, Ni and V acted additively at their highest sub-lethal concentrations. Aqueous chemistry and toxicity of Ni and V are discussed with the goal of informing reclamation efforts at the Athabasca oil sands. PMID:22138340

  17. Molecular Mechanism of Heavy Metal Toxicity and Tolerance in Plants: Central Role of Glutathione in Detoxification of Reactive Oxygen Species and Methylglyoxal and in Heavy Metal Chelation

    Directory of Open Access Journals (Sweden)

    Mohammad Anwar Hossain

    2012-01-01

    Full Text Available Heavy metal (HM toxicity is one of the major abiotic stresses leading to hazardous effects in plants. A common consequence of HM toxicity is the excessive accumulation of reactive oxygen species (ROS and methylglyoxal (MG, both of which can cause peroxidation of lipids, oxidation of protein, inactivation of enzymes, DNA damage and/or interact with other vital constituents of plant cells. Higher plants have evolved a sophisticated antioxidant defense system and a glyoxalase system to scavenge ROS and MG. In addition, HMs that enter the cell may be sequestered by amino acids, organic acids, glutathione (GSH, or by specific metal-binding ligands. Being a central molecule of both the antioxidant defense system and the glyoxalase system, GSH is involved in both direct and indirect control of ROS and MG and their reaction products in plant cells, thus protecting the plant from HM-induced oxidative damage. Recent plant molecular studies have shown that GSH by itself and its metabolizing enzymes—notably glutathione S-transferase, glutathione peroxidase, dehydroascorbate reductase, glutathione reductase, glyoxalase I and glyoxalase II—act additively and coordinately for efficient protection against ROS- and MG-induced damage in addition to detoxification, complexation, chelation and compartmentation of HMs. The aim of this review is to integrate a recent understanding of physiological and biochemical mechanisms of HM-induced plant stress response and tolerance based on the findings of current plant molecular biology research.

  18. Application of carbon foam for heavy metal removal from industrial plating wastewater and toxicity evaluation of the adsorbent.

    Science.gov (United States)

    Lee, Chang-Gu; Song, Mi-Kyung; Ryu, Jae-Chun; Park, Chanhyuk; Choi, Jae-Woo; Lee, Sang-Hyup

    2016-06-01

    Electroplating wastewater contains various types of toxic substances, such as heavy metals, solvents, and cleaning agents. Carbon foam was used as an adsorbent for the removal of heavy metals from real industrial plating wastewater. Its sorption capacity was compared with those of a commercial ion-exchange resin (BC258) and a heavy metal adsorbent (CupriSorb™) in a batch system. The experimental carbon foam has a considerably higher sorption capacity for Cr and Cu than commercial adsorbents for acid/alkali wastewater and cyanide wastewater. Additionally, cytotoxicity test showed that the newly developed adsorbent has low cytotoxic effects on three kinds of human cells. In a pilot plant, the carbon foam had higher sorption capacity for Cr (73.64 g kg(-1)) than for Cu (14.86 g kg(-1)) and Ni (7.74 g kg(-1)) during 350 h of operation time. Oxidation pretreatments using UV/hydrogen peroxide enhance heavy metal removal from plating wastewater containing cyanide compounds. PMID:26999028

  19. Layered Double Hydroxides as Effective Adsorbents for U(VI and Toxic Heavy Metals Removal from Aqueous Media

    Directory of Open Access Journals (Sweden)

    G. N. Pshinko

    2013-01-01

    Full Text Available Capacities of different synthesized Zn,Al-hydrotalcite-like adsorbents, including the initial carbonate [Zn4Al2(OH12]·CO3·8H2O and its forms intercalated with chelating agents (ethylenediaminetetraacetic acid (EDTA, diethylenetriaminepentaacetic acid (DTPA, and hexamethylenediaminetetraacetic acid (HMDTA and heat-treated form Zn4Al2O7, to adsorb uranium(VI and ions of toxic heavy metals have been compared. Metal sorption capacities of hydrotalcite-like adsorbents have been shown to correlate with the stability of their complexes with the mentioned chelating agents in a solution. The synthesized layered double hydroxides (LDHs containing chelating agents in the interlayer space are rather efficient for sorption purification of aqueous media free from U(VI irrespective of its forms of natural abundance (including water-soluble bi- and tricarbonate forms and from heavy metal ions. [Zn4Al2(OH12]·EDTA·nH2O is recommended for practical application as one of the most efficient and inexpensive synthetic adsorbents designed for recovery of both cationic and particularly important anionic forms of U(VI and other heavy metals from aqueous media. Carbonate forms of LDHs turned out to be most efficient for recovery of Cu(II from aqueous media with pH0≥7 owing to precipitation of Cu(II basic carbonates and Cu(II hydroxides. Chromate ions are efficiently adsorbed from water only by calcinated forms of LDHs.

  20. Batch and column studies of the stabilization of toxic heavy metals in dredged marine sediments by hematite after bioremediation.

    Science.gov (United States)

    Mamindy-Pajany, Yannick; Geret, Florence; Hurel, Charlotte; Marmier, Nicolas

    2013-08-01

    The management of dredged sediments is an important issue in coastal regions where the marine sediments are highly polluted by metals and organic pollutants. In this paper, mineral-based amendments (hematite, zero-valent iron and zeolite) were used to stabilize metallic pollutants (As, Cd, Cu, Mo, Ni, Pb, and Zn) in a contaminated marine sediment sample. Mineral-based amendments were tested at three application rates (5 %, 10 %, and 15 %) in batch experiments in order to select the best amendment to perform column experiments. Batch tests have shown that hematite was the most efficient amendment to stabilize inorganic pollutants (As, Cd, Cu, Mo, Ni, Pb, and Zn) in the studied sediment. Based on batch tests, hematite was used at one application rate equal to 5 % to conduct column experiments. Column tests confirmed that hematite was able to decrease metal concentrations in leachates from stabilized sediment. The stabilization rates were particularly high for Cd (67 %), Mo (80 %), and Pb (90 %). The Microtox solid phase test showed that hematite could decrease significantly the toxicity of stabilized sediment. Based on batch and column experiments, it emerged that hematite could be a suitable adsorbent to stabilize metals in dredged marine sediment. PMID:23370851

  1. Evaluation of Airborne Particulate Matter and Metals Data in Personal, Indoor and Outdoor Environments using ED-XRF and ICP-MS and Co-located Duplicate Samples

    Science.gov (United States)

    Factors and sources affecting measurement uncertainty in airborne particulate matter (PM) gravimetric measurements and elemental analyses were investigated as part of the Windsor Ontario Exposure Assessment Study (WOEAS). The assessment was made using co-located duplicate sample...

  2. Heavy metal uptake and toxicity in the presence of titanium dioxide nanoparticles: a factorial approach using Daphnia magna.

    Science.gov (United States)

    Rosenfeldt, Ricki R; Seitz, Frank; Schulz, Ralf; Bundschuh, Mirco

    2014-06-17

    Unintentionally released titanium dioxide nanoparticles (nTiO2) may co-occur in aquatic environments together with other stressors, such as, metal ions. The effects of P25-nTiO2 on the toxicity and uptake of the elements silver (Ag), arsenic (As) and copper (Cu) were assessed by applying a factorial test design. The test design consisted of two developmental stages of Daphnia magna, two levels of nTiO2 (0 versus 2 mg/L) as well as seven nominal test concentrations of the respective element. The presence of nTiO2 increased Ag toxicity for juveniles as indicated by a 40% lower 72-h EC50, while the toxicities of As and Cu were reduced by up to 80%. This reduction was even more pronounced for Cu in the presence of dissolved organic carbon (i.e., seaweed extract) and nTiO2. This outcome coincides with the body burden of the elements, which was elevated 2-fold for Ag and decreased 14-fold for Cu in the presence of nTiO2. Although the underlying mechanisms could not be uncovered, the data suggest that the carrier function of nTiO2 plays a central role. However, to understand the processes and mechanisms occurring in the field due to the presence of nTiO2 further systematic investigations considering environmental variables and nanoparticle characteristics are required. PMID:24847969

  3. FINE PARTICAL AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Jost O.L. Wendt; Wayne S. Seames; Art Fernandez

    2003-09-21

    This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and pulverized coal. The objective was to determine potential tradeoffs between CO{sub 2} mitigation through using a CO{sub 2} neutral fuel, such as municipal sewage sludge, and the emergence of other potential problems such as the emission of toxic fly ash particles. The work led to new insight into mechanisms governing the partitioning of major and trace metals from the combustion of sewage sludge, and mixtures of coal and sewage sludge. The research also showed that the co-combustion of coal and sewage sludge emitted fine particulate matter that might potentially cause greater lung injury than that from the combustion of either coal alone or municipal sewage sludge alone. The reason appeared to be that the toxicity measured required the presence of large amounts of both zinc and sulfur in particles that were inhaled. MSS provided the zinc while coal provided the sulfur. Additional research showed that the toxic effects could most likely be engineered out of the process, through the introduction of kaolinite sorbent downstream of the combustion zone, or removing the sulfur from the fuel. These results are consequences of applying ''Health Effects Engineering'' to this issue. Health Effects Engineering is a new discipline arising out of this work, and is derived from using a collaboration of combustion engineers and toxicologists to mitigate the potentially bad health effects from combustion of this biomass fuel.

  4. Occurrence of multidrug-resistant and toxic-metal tolerant enterococci in fresh feces from urban pigeons in Brazil.

    Science.gov (United States)

    da Silva, Vânia Lúcia; Caçador, Natália Cândido; da Silva, Carolina dos Santos Fernandes; Fontes, Cláudia Oliveira; Garcia, Gizele Duarte; Nicoli, Jacques Robert; Diniz, Cláudio Galuppo

    2012-01-01

    Enterococcus are emerging as important putative pathogens resistant to chemicals that are widely released into the environment, and urban pigeons might act as a natural reservoir contributing to the spread of resistant strains. This study aimed to evaluate the occurrence of Enterococcus in pigeon feces and their antimicrobial and toxic metal susceptibility. Bacteria were isolated and identified from 150 fresh feces by phenotypic and genetic techniques. Antimicrobial and toxic metal susceptibility was determined by the agar dilution method, and the multiple antibiotic resistance index (MAR) was calculated. Out of 120 isolates, no resistance was observed against penicillin and vancomycin, but was observed against gentamicin (55.8%), chloramphenicol (21.7%), tetracycline (13.3%), ciprofloxacin (8.4%) and rifampin (2.5%). 18.3% presented a MAR index ≥0.2, ranging between 0.14 to 0.57, indicating resistance to more than one antimicrobial. All samples were tolerant to >1024 µg mL⁻¹ zinc and chromium. Minimal inhibitory concentration (MIC) of 1,024 µg mL⁻¹ was observed for copper (100%) and nickel (71.4%). Mercury inhibited 88.4% at 32 µg mL⁻¹ and the MIC for cadmium ranged from 0.125-128 µg mL⁻¹. Since pigeons were found to harbor drug-resistant Enterococcus, our data support that their presence in the urban environment may contribute to the spread of resistance, with an impact on public health. PMID:22791051

  5. Comparison of toxic heavy metals concentration in medicinal plants and their respective branded herbal formulations commonly available in Khyber Pakhtunkhwa.

    Science.gov (United States)

    Shah, Waheed Ali; Zakiullah; Khuda, Fazli; Khan, Faridullah; Saeed, Muhammad

    2016-07-01

    The present study was conducted on fifteen medicinal plants and their respective branded formulations, commonly used in Khyber Pakhtunkhwa, for the evaluation of toxic heavy metals. The purpose of the study was to assess the toxic profile of the crude medicinal plants with respect to the worldwide permissible limits of metal concentrations and to correlate it with their respective herbal formulations available on the market. Chromium (Cr), Copper (Cu), Lead (Pb), Manganese (Mn) and Nickel (Ni) content were evaluated using wet digestion and Atomic Absorption Spectrophotometry technique. The results exhibited that in 100% of the analyzed medicinal plants Cr and Ni are present in excess of the maximum limits, Cu and Pb in 73% and 60% respectively, while Mn is in the normal range. Likewise in the respective branded formulations Cr and Ni exceed the normal limit in 100% of the products, Cu and Pb in 27% and 20% of the products respectively, while Mn is in the normal range. It indicates that majority of people in Pakistan who frequently use herbal drugs in various forms are exposed to the hazardous elements, which may pose serious health effects. Regulatory measures should therefore be taken to protect the general public from their hazardous health effects. PMID:27393438

  6. A multifunctional DNA origami as carrier of metal complexes to achieve enhanced tumoral delivery and nullified systemic toxicity.

    Science.gov (United States)

    Huang, Yanyu; Huang, Wei; Chan, Leung; Zhou, Binwei; Chen, Tianfeng

    2016-10-01

    The use of metal complexes in cancer treatment is hampered by the insufficient accumulation in tumor regions and observable systemic toxicity due to their nonspecificity in vivo. Herein we present a cancer-targeted DNA origami as biocompatible nanocarrier of metal complexes to achieve advanced antitumor effect. The formation of unique tetrahedral nanostructure of DNA cages effectively enhances the interaction between ruthenium polypyridyl complexes (RuPOP) and the cages, thus increasing the drug loading efficacy. Conjugation of biotin to the DNA-based nanosystem (Bio-cage@Ru) enhances its specific cellular uptake, drug retention and cytotoxicity against HepG2 cells. Different from free RuPOP and the cage itself, Bio-cage@Ru translocates to cell nucleus after internalization, where it undergoes self-immolative cleavage in response to DNases, leading to triggered drug release and induction of ROS-mediated cell apoptosis. Moreover, in the nude mice model, the nanosystem specifically accumulates in tumor sites, thus exhibits satisfactory in vivo antitumor efficacy, and alleviates the damage of liver, kidney, lung and heart function of nude mice induced by RuPOP and tumor xenografts. Collectively, this study demonstrates a strategy for construction of biocompatible and cancer-targeted DNA origami with enhanced anticancer efficacy and reduced toxicity for next-generation cancer therapy. PMID:27388944

  7. Removal and recovery of radionuclides and toxic metals from wastes, soils and materials

    Energy Technology Data Exchange (ETDEWEB)

    Francis, A.J.

    1993-07-01

    A process has been developed at Brookhaven National Laboratory (BNL) for the removal of metals and radionuclides from contaminated materials, soils, and waste sites (Figure 1). In this process, citric acid, a naturally occurring organic complexing agent, is used to extract metals such as Ba, Cd, Cr, Ni, Zn, and radionuclides Co, Sr, Th, and U from solid wastes by formation of water soluble, metal-citrate complexes. Citric acid forms different types of complexes with the transition metals and actinides, and may involve formation of a bidentate, tridentate, binuclear, or polynuclear complex species. The extract containing radionuclide/metal complex is then subjected to microbiological degradation followed by photochemical degradation under aerobic conditions. Several metal citrate complexes are biodegraded and the metals are recovered in a concentrated form with the bacterial biomass. Uranium forms binuclear complex with citric acid and is not biodegraded. The supernatant containing uranium citrate complex is separated and upon exposure to light, undergoes rapid degradation resulting in the formation of an insoluble, stable polymeric form of uranium. Uranium is recovered as a precipitate (uranium trioxide) in a concentrated form for recycling or for appropriate disposal. This treatment process, unlike others which use caustic reagents, does not create additional hazardous wastes for disposal and causes little damage to soil which can then be returned to normal use.

  8. Removal and recovery of radionuclides and toxic metals from wastes, soils and materials

    International Nuclear Information System (INIS)

    A process has been developed at Brookhaven National Laboratory (BNL) for the removal of metals and radionuclides from contaminated materials, soils, and waste sites (Figure 1). In this process, citric acid, a naturally occurring organic complexing agent, is used to extract metals such as Ba, Cd, Cr, Ni, Zn, and radionuclides Co, Sr, Th, and U from solid wastes by formation of water soluble, metal-citrate complexes. Citric acid forms different types of complexes with the transition metals and actinides, and may involve formation of a bidentate, tridentate, binuclear, or polynuclear complex species. The extract containing radionuclide/metal complex is then subjected to microbiological degradation followed by photochemical degradation under aerobic conditions. Several metal citrate complexes are biodegraded and the metals are recovered in a concentrated form with the bacterial biomass. Uranium forms binuclear complex with citric acid and is not biodegraded. The supernatant containing uranium citrate complex is separated and upon exposure to light, undergoes rapid degradation resulting in the formation of an insoluble, stable polymeric form of uranium. Uranium is recovered as a precipitate (uranium trioxide) in a concentrated form for recycling or for appropriate disposal. This treatment process, unlike others which use caustic reagents, does not create additional hazardous wastes for disposal and causes little damage to soil which can then be returned to normal use

  9. A geochemical study of toxic metal translocation in an urban brownfield wetland

    International Nuclear Information System (INIS)

    Rhizosphere soil and dominant plant samples were collected at a brownfield site in New Jersey, USA, during summer 2005 to evaluate plant metal uptake from the contaminated soils. Metal concentrations varied from 4.25 to 978 μg g−1 for As, 9.68–209 μg g−1 for Cr, 23.9–1870 μg g−1 for Cu, and 24.8–6502 μg g−1 for Zn. A wide range of metal uptake efficiencies in the roots, stems and leaves was found in this study. Data showed that (1) Betula populifolia has high Zn, Cu and As accumulations in the root, and high concentrations of Cu and Zn in the stem and the leaf; (2) Rhus copallinum has high accumulation of Zn and Cr in the leaf and Cu in the stem; (3) Polygonum cuspidatum has high accumulations of Cu and As in the root; and (4) Artemisia vulgaris shows high Cu accumulation in the leaf and the stem. - Highlights: ► Rhizosphere soil and dominant plant samples were studied at a brownfield. ► Plant roots showed exceptional capacity of heavy metal accumulation. ► Metal uptake efficiency decrease with the increases of pH and organic matter. ► Variations in metal uptake efficiency in the root, stem and leave were found. - Metal uptake by brownfield wetland plants in the New York/New Jersey metropolitan area.

  10. Physicochemical and spectroscopic properties of natural organic matter (NOM) from various sources and implications for ameliorative effects on metal toxicity to aquatic biota

    International Nuclear Information System (INIS)

    Natural organic matter (NOM), expressed as dissolved organic carbon (DOC in mg C L-1), is an ubiquitous complexing agent in natural waters, and is now recognized as an important factor mitigating waterborne metal toxicity. However, the magnitude of the protective effect, judged by toxicity measures (e.g. LC50), varies substantially among different NOM sources even for similar DOC concentrations, implying a potential role of NOM physicochemical properties or quality of NOM. This review summarizes some key quality parameters for NOM samples, obtained by reverse osmosis, and by using correlation analyses, investigates their contribution to ameliorating metal toxicity towards aquatic biota. At comparable and environmentally realistic DOC levels, molecular spectroscopic characteristics (specific absorbance coefficient, SAC, and fluorescence index, FI) as well as concentrations of fluorescent fractions obtained from mathematical mixture resolution techniques (PARAFAC), explain considerable variability in the protective effects. NOM quality clearly influences the toxicity of copper (Cu) and lead (Pb). NOM quality may also influence the toxicity of silver (Ag), cadmium (Cd) and inorganic mercury (Hg), but as yet insufficient data are available to unequivocally support the latter correlations between toxicity reduction and NOM quality predictors. Cu binding capacities, protein-to-carbohydrate ratio, and lipophilicity, show insignificant correlation to the amelioration offered by NOMs, but these conclusions are based on data for Norwegian NOMs with very narrow ranges for the latter two parameters. Certainly, various NOMs alleviate metal toxicity differentially and therefore their quality measures should be considered in addition to their quantity.

  11. Assessment of toxicity potential of metallic elements in discarded electronics:A case study of mobile phones in China

    Institute of Scientific and Technical Information of China (English)

    B. Y. Wu; Y. C. Chan; A. Middendorf; X. Gu; H. W. Zhong

    2008-01-01

    The electronic waste (e-waste) is increasingly flooding Asia, especially China. E-waste could precipitate a growing volume of toxic input to the local environment if it was not handed properly. This makes the evaluation of environmental impact from electronics an essentially important task for the life cycle assessment (LCA) and the end-of-life management of electronic products. This study presented a quantitative investigation on the environmental performance of typical electronics. Two types of disposed mobile phones (MPs), as a representative of consumer electronics, were evaluated in terms of toxicity potential indicator (TPI) with an assumption of worst-case scenario. It is found that the composition and the percentages of constituents in MPs are similar. More than 20 metallic elements make up 35 wt.%-40 wt.% of the total weight, of which 12 elements are identified to be highly hazardous and 12 are less harmful. With the TPI technique, the environmental performance of Pb is attributed to be 20.8 mg-1. The total TPIs of metallic elements in the old and new type MP is 255,403 and 127,639 units, respectively, which is equivalent to the effect of releasing 6.14 and 12.28g Pb into the environment. The average TPI of the old and new type MP is 4.1 and 4.5 mg-1, respectively, which suggests a similar eco-efficiency per unit mass. The new model of MP is more eco-effective than the old one, which is not due to a reduction in the type of hazardous elements, but rather due to a significant miniaturization of the package with less weight. A single MP can have a considerable toxicity to the environment as referred to Pb, which suggests a major concern for the environmental impact of the total e-waste with a huge quantity and a heavy mass in China.

  12. Geochemical characteristics and microbial community composition in toxic metal-rich sediments contaminated with Au-Ag mine tailings.

    Science.gov (United States)

    Kwon, Man Jae; Yang, Jung-Seok; Lee, Seunghak; Lee, Giehyeon; Ham, Baknoon; Boyanov, Maxim I; Kemner, Kenneth M; O'Loughlin, Edward J

    2015-10-15

    The effects of extreme geochemical conditions on microbial community composition were investigated for two distinct sets of sediment samples collected near weathered mine tailings. One set (SCH) showed extraordinary geochemical characteristics: As (6.7-11.5%), Pb (1.5-2.1%), Zn (0.1-0.2%), and pH (3.1-3.5). The other set (SCL) had As (0.3-1.2%), Pb (0.02-0.22%), and Zn (0.01-0.02%) at pH 2.5-3.1. The bacterial communities in SCL were clearly different from those in SCH, suggesting that extreme geochemical conditions affected microbial community distribution even on a small spatial scale. The clones identified in SCL were closely related to acidophilic bacteria in the taxa Acidobacterium (18%), Acidomicrobineae (14%), and Leptospirillum (10%). Most clones in SCH were closely related to Methylobacterium (79%) and Ralstonia (19%), both well-known metal-resistant bacteria. Although total As was extremely high, over 95% was in the form of scorodite (FeAsO4·2H2O). Acid-extractable As was only ∼118 and ∼14 mg kg(-1) in SCH and SCL, respectively, below the level known to be toxic to bacteria. Meanwhile, acid-extractable Pb and Zn in SCH were above toxic concentrations. Because As was present in an oxidized, stable form, release of Pb and/or Zn (or a combination of toxic metals in the sediment) from the sediment likely accounts for the differences in microbial community structure. The results also suggest that care should be taken when investigating mine tailings, because large differences in chemical/biological properties can occur over small spatial scales. PMID:25917692

  13. Heavy metals toxicity and bioaccumulation in vegetables from potentially polluted area

    OpenAIRE

    Balabanova, Biljana; Stafilov, Trajče; Baceva, Katerina; Vuckovic, Ivana

    2013-01-01

    Food safety and quality are a major public concern worldwide, regarding the risk associated with consumption of food stuffs contaminated with heavy metals as toxins. The levels of 8 elements contents were determined in various vegetables [garlic (Allium sativum), onion (Allium cepa) and parsley (Petroselinum crispum)], cultivated around copper mine environ. Bioaccumulation and mobility of heavy metals were determinate with three soil extraction methods: in 0.1 M HCl; in H2O and in a mixed buf...

  14. EFFECT OF INDUCED TOXIC PATHOLOGICAL EFFECT OF PHARMACEUTICAL AGENTS AND HEAVY METALS ON BROILER BIRDS

    Directory of Open Access Journals (Sweden)

    Ganguly Subha

    2013-06-01

    Full Text Available The indiscriminate and injudicious use of second generation fluoroquinolones viz., enrofloxacin produced anemia, leucopenia, hypoglycaemia, hypoproteinemia, increased enzymatic activity and hepatotoxic and nephrotoxic effects in broiler chickens. Exposure to heavy metals results in congestion and hemorrhages in the lungs, tubular degeneration in kidneys and occasional hemorrhages in the brain. The present article was conducted to review the various pharmaceutical, physiological and toxicopathological effects of different chemical agents and heavy metals due to environmental exposure and through feed on poultry birds.

  15. Dynamics of metal availability and toxicity in historically polluted floodplain sediments

    OpenAIRE

    Geest, van der, S.; León Paumen, M.

    2008-01-01

    Many floodplains contain high concentrations of sediment associated contaminants that might be subjected to large changes in terms of mobility, transformation and bioavailability. Therefore, this study describes 1) changes in the redox conditions and the mobility of metals in artificially uncovered polluted floodplain sediments, 2) metal uptake by organisms and 3) colonization, succession and functioning of benthic algae on these sediments. Flooding caused long term changes in redox potential...

  16. Removal of toxic metals from aqueous solutions by fungal biomass of Agaricus macrosporus

    Energy Technology Data Exchange (ETDEWEB)

    Melgar, M.J. E-mail: mjmelgar@lugo.usc.es; Alonso, J.; Garcia, M.A

    2007-10-15

    Fungi such as Agaricus macrosporus show potential for the removal of heavy metals from aqueous solutions contaminated by zinc, copper, mercury, cadmium or lead. This study investigated biosorption of these metals by living or non-living biomass of A. macrosporus from an acid solution, an acid solution supplemented with potassium and phosphorus, and an alkaline solution. Uptake showed a pH-dependent profile. Maximum percentage uptake of all metals was found to occur at alkaline pH (Cu 96%, Pb 89%). With living biomass, metal biosorption was greater and faster in K/P-supplemented acid medium than in non-supplemented acid medium, with equilibrium reached within 15 min for all metals, and the highest percentage uptake being of cadmium (96%). In general, the greatest differences in biosorption capacity were seen for living biomass, between supplemented and non-supplemented acid medium; the smallest differences were between living and dead biomass in alkaline medium. These results support the potential utility of A. macrosporus for heavy metal removal.

  17. Single and combined toxicity of copper and cadmium to H. vulgare growth and heavy metal bioaccumulation

    Directory of Open Access Journals (Sweden)

    Žaltauskaitė J.

    2013-04-01

    Full Text Available The single and combined effects of copper (Cu and cadmium (Cd (0.1-10 mg L−1 in spring barley (Hordeum vulgare L. plants grown in hydroponics are investigated. The aim of the study was to investigate the interactive effect of the binary mixture of Cu and Cd to the growth of H. vulgare and accumulation of these metals by the plants. Single and combined metal treatment led to major effects in the growth of roots and shoots and dry weight of barley. Exposure to metals altered the content of photosynthetic pigments and caused lipid peroxidation. It was observed that combined effects of heavy metals to plants are endpoint and concentration depending. The binary mixture Cu+Cd exhibited additive or less than additive interaction for dry weight, root length and shoot height. Analysis of tissue metal concentrations showed that Cu and Cd were mainly accumulated in the roots and the combination of Cu+Cd had less than additive response of metal bioaccumulation in the leaves and roots.

  18. 公路两侧大气颗粒物中的重金属污染特征及其影响因素%Pollution characterization and controlling factors of heavy metals in airborne particulate matter near expressway

    Institute of Scientific and Technical Information of China (English)

    邵莉; 肖化云

    2012-01-01

    Metal concentrations were measured in different size airborne particles collected near two expressways with different traffic densities from April 2009 to June 2009.The pollution characterization and distribution mode of Zn,Pb,Mn,Cu,Cd,Sb in airborne particles were studied to discuss the influence of traffic volume,particle size,weather and distance.The results show that Zn concentration in airborne particles was the highest,followed by Pb,Mn,Cu,Cd,and Sb concentration was the lowest.The metal concentration was highly dependent on traffic volume,indicating that traffic was the main source of these metals.The high concentrations of Zn and Mn in PM10(possibly originated from gas exhaust) and 10 μmDa50≤100 μm particles(possibly associated with tire wear) suggest that gas exhaust and tire wear were the main sources of Zn and Mn.Antimony(Sb) existed mostly in PM10 and originated mainly from the wear of brake linings.The concentration of Cu was high in both PM10 and 10 μmDa50≤100 μm particles,suggesting that Cu had other sources than the wear of brake linings.Lead(Pb) and Cd existed mainly in PM10.Weather mainly influenced the Zn concentration,but not other metals.Within 10 meters from the expressway,the metal concentration decreased little.The concentrations of Pb,Sb in the countryside was noticeably lower as compared with their concentrations near the expressway,which may be explained by the fact that the main source of airborne Pb,Sb was traffic.%选择昌九高速公路(赣粤高速公路南昌至九江段)、昌樟高速公路(赣粤高速公路南昌至樟树段)为研究对象,采集了公路两侧10μm

  19. Identifying Biomarkers and Mechanisms of Toxic Metal Stress with Global Proteomics

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Susan M.

    2012-04-16

    Hg is a wide-spread contaminant in the environment and is toxic in all of its various forms. Data suggest that RHg+ and Hg2+ are toxic in two ways. At low levels, Hg species appear to disrupt membrane-bound respiration causing a burst of reactive oxygen species (ROS) that further damage the cell. At higher Hg concentrations, RHg+ and Hg2+ may form adducts with cysteine- and selenocysteine-containing proteins in all cellular compartments resulting in their inactivation. Although these mechansims for toxicity are generally accepted, the most sensitive targets associated with these mechanisms are not well understood. In this collaborative project involving three laboratories at three institutions, the overall goal was to develop of a mass spectrometry-based global proteomics methodology that could be used to identify Hg-adducted (and ideally, ROS-damaged) proteins in order to address these types of questions. The two objectives of this overall collaborative project were (1) to identify, quantify, and compare ROS- and Hg-damaged proteins in cells treated with various Hg species and concentrations to test this model for two mechanisms of Hg toxicity, and (2) to define the cellular roles of the ubiquitous bacterial mercury resistance (mer) locus with regards to how the proteins of this pathway interact to protect other cell proteins from Hg damage. The specific objectives and accomplishments of the Miller lab in this project included: (1) Development of algorithms for analysis of the Hg-proteomic mass spectrometry data to identify mercury adducted peptides and other trends in the data. (2) Investigation of the role of mer operon proteins in scavenging Hg(II) from other mer pathway proteins as a means of protecting cellular proteins from damage.

  20. Air toxics from heavy oil production and consumption

    International Nuclear Information System (INIS)

    This report assesses the potential impact of recent Federal and state regulations for airborne toxic substances on the production and consumption of heavy fuel oils. Emissions of nickel from heavy oil production in California are considered in some detail, in conjunction with California state regulations for toxic emissions. Although the use of thermal energy from heavy crude oils could in theory be impacted by toxic air pollution regulations, recent trends towards the use of natural gas for the required extraction energy appear to provide substantial relief, in addition to reducing emissions of criteria air pollutants. However, the consumption of residual fuel oils containing toxic metals could result in higher population exposures to these substances and their attendant risks may be worthy of more detailed analysis

  1. The Role of the Component Metals in the Toxicity of Military-Grade Tungsten Alloy

    Directory of Open Access Journals (Sweden)

    Christy A. Emond

    2015-12-01

    Full Text Available Tungsten-based composites have been recommended as a suitable replacement for depleted uranium. Unfortunately, one of these mixtures composed of tungsten (W, nickel (Ni and cobalt (Co induced rhabdomyosarcomas when implanted into the leg muscle of laboratory rats and mice to simulate a shrapnel wound. The question arose as to whether the neoplastic effect of the mixture could be solely attributed to one or more of the metal components. To investigate this possibility, pellets with one or two of the component metals replaced with an identical amount of the biologically-inert metal tantalum (Ta were manufactured and implanted into the quadriceps of B6C3F1 mice. The mice were followed for two years to assess potential adverse health effects. Implantation with WTa, CoTa or WNiTa resulted in decreased survival, but not to the level reported for WNiCo. Sarcomas in the implanted muscle were found in 20% of the CoTa-implanted mice and 5% of the WTa- and WCoTa-implanted rats and mice, far below the 80% reported for WNiCo-implanted mice. The data obtained from this study suggested that no single metal is solely responsible for the neoplastic effects of WNiCo and that a synergistic effect of the three metals in tumor development was likely.

  2. Concentrations of toxic heavy metals in ambient particulate matter in an industrial area of northeastern China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper investigates concentrations of various heavy metals in ambient particulate matter(PM)and provide evidence for prevention from air pollution.The concentrations of heavy metal components in the PM were determined by inductively coupled plasma/Mass spectrometry(ICP/MS)from September 2000 to August 2002 in a northeast industrial city in China.Concentrations of Cd,Mn,Pb,Ni,Cr and As in the PM were 9.3,461.9,588.7,69.5,205.7 and 57.4 ng/m3 in the industrial area,and 5.7,245.5,305.0,31.4,58.8 and 32.5 ng/m3 in the main road,respectively.Concentrations of these heavy metals except Cd were significantly higher in the industrial area and main road than those in the suburban area(P<0.05 or P<0.01).The change curves of the six heavy metal concentrations show their concentrations increased in the winter and spring,but decreased in the summer and autumn.The results indicate that concentrations of the metals in the PM are relatively high in the indu.strial area and main road.

  3. A self-adjustable four-point probing system using polymeric three dimensional coils and non-toxic liquid metal

    Science.gov (United States)

    Oyunbaatar, Nomin-Erdene; Choi, Young Soo; Lee, Dong-Weon

    2015-12-01

    This paper describes a self-adjustable four-point probe (S4PP) system with a square configuration. The S4PP system consists of 3D polymer coil springs for the independent operation of each tungsten (W) probe, microfluidic channels filled with a nontoxic liquid metal, and a LabView-based control system. The 3D coil springs made by PMMA are fabricated with a 3D printer and are positioned in a small container filled with the non-toxic liquid metal. This unique configuration allows independent self-adjustment of the probe heights for precise measurements of the electrical properties of both flexible and large-step-height microsamples. The feasibility of the fabricated S4PP system is evaluated by measuring the specific resistance of Cr and Au thin films deposited on silicon wafers. The system is then employed to evaluate the electrical properties of a Au thin film deposited onto a flexible and easily breakable silicon diaphragm (spring constant: ˜3.6 × 10-5 N/m). The resistance of the Cr thin films (thickness: 450 nm) with step heights of 60 and 90 μm is also successfully characterized. These experimental results indicate that the proposed S4PP system can be applied to common metals and semiconductors as well as flexible and large-step-height samples.

  4. Heavy metal toxicity and bioavailability of dissolved nutrients to a bacterivorous flagellate are linked to suspended particle physical properties

    International Nuclear Information System (INIS)

    Many dissolved substances attach easily to sediment particles. In the presence of suspended sediments bioavailability of dissolved substances is therefore, usually reduced and clays are even applied to 'wash' natural waters upon pollution. In organisms which feed on food organisms in the size range of these suspended sediment particles, however, bioavailability of such substances may even increase. For microorganisms the interaction with dissolved substances and suspended sediment particles so far has hardly been investigated. We specifically tested: (1) the importance of suspended particles as an uptake route for dissolved substances; and (2) the significance of particle surface properties, i.e. surface load and mineralogy. As a model system we used an axenically cultured strain of a widespread and often abundant flagellate ('Spumella-like' flagellate strain JBM10). We tested the toxicity of cadmium (II) and mercury (II) as well as availability of dissolved organic matter (DOM) in the absence as well as in the presence of different natural clays, i.e. a kaolinite, a montmorillonite, and a mixed clay, and of artificial silicate particles of different surface charge. When applied separately the presence of the heavy metals cadmium and mercury as well as of suspended particles negatively affected the investigated flagellate but nutritive organics supported growth of the investigated flagellate. Toxic stress response comprises behavioral changes including enhanced swimming activity and stress egestion of ingested particles and was generally similar for a variety of different flagellate species. In combination with suspended particles, the respective effect of trace metals and nutritive substances decreased. Regarding the particle quality, cadmium toxicity increased with increasingly negative surface charge, i.e. increasing surface density of silanol groups (Pearson's product moment, P = 0.005). For mercury particle mineralogy still had a significant effect (P < 0

  5. In vitro profiling of epigenetic modifications underlying heavy metal toxicity of tungsten-alloy and its components

    International Nuclear Information System (INIS)

    Tungsten-alloy has carcinogenic potential as demonstrated by cancer development in rats with intramuscular implanted tungsten-alloy pellets. This suggests a potential involvement of epigenetic events previously implicated as environmental triggers of cancer. Here, we tested metal induced cytotoxicity and epigenetic modifications including H3 acetylation, H3-Ser10 phosphorylation and H3-K4 trimethylation. We exposed human embryonic kidney (HEK293), human neuroepithelioma (SKNMC), and mouse myoblast (C2C12) cultures for 1-day and hippocampal primary neuronal cultures for 1-week to 50-200 μg/ml of tungsten-alloy (91% tungsten/6% nickel/3% cobalt), tungsten, nickel, and cobalt. We also examined the potential role of intracellular calcium in metal mediated histone modifications by addition of calcium channel blockers/chelators to the metal solutions. Tungsten and its alloy showed cytotoxicity at concentrations > 50 μg/ml, while we found significant toxicity with cobalt and nickel for most tested concentrations. Diverse cell-specific toxic effects were observed, with C2C12 being relatively resistant to tungsten-alloy mediated toxic impact. Tungsten-alloy, but not tungsten, caused almost complete dephosphorylation of H3-Ser10 in C2C12 and hippocampal primary neuronal cultures with H3-hypoacetylation in C2C12. Dramatic H3-Ser10 dephosphorylation was found in all cobalt treated cultures with a decrease in H3 pan-acetylation in C2C12, SKNMC and HEK293. Trimethylation of H3-K4 was not affected. Both tungsten-alloy and cobalt mediated H3-Ser10 dephosphorylation were reversed with BAPTA-AM, highlighting the role of intracellular calcium, confirmed with 2-photon calcium imaging. In summary, our results for the first time reveal epigenetic modifications triggered by tungsten-alloy exposure in C2C12 and hippocampal primary neuronal cultures suggesting the underlying synergistic effects of tungsten, nickel and cobalt mediated by changes in intracellular calcium homeostasis and

  6. Impact of toxic heavy metals and pesticide residues in herbal products

    Directory of Open Access Journals (Sweden)

    Nema S. Shaban

    2016-03-01

    Full Text Available Medicinal plants have a long history of use in therapy throughout the world and still make an important part of traditional medicine. The World Health Organization (WHO estimates that 65%–80% of the world's populations depend on the herbal products as their primary form of health care. This review is conducted to provide a general idea about chemical contaminants such as heavy metals and pesticide residues as major common contaminants of the herbal medicine, which impose serious health risks to human health. Additionally, we aim to provide different analytical methods for analysis of heavy metals and pesticide residues in the herbal medicine.

  7. Quantitative assessment of atmospheric emissions of toxic heavy metals from anthropogenic sources in China: historical trend, spatial distribution, uncertainties, and control policies

    Science.gov (United States)

    Tian, H. Z.; Zhu, C. Y.; Gao, J. J.; Cheng, K.; Hao, J. M.; Wang, K.; Hua, S. B.; Wang, Y.; Zhou, J. R.

    2015-09-01

    Anthropogenic atmospheric emissions of typical toxic heavy metals have caused worldwide concern due to their adverse effects on human health and the ecosystem. By determining the best available representation of time-varying emission factors with S-shape curves, we establish the multiyear comprehensive atmospheric emission inventories of 12 typical toxic heavy metals (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu, and Zn) from primary anthropogenic activities in China for the period of 1949-2012 for the first time. Further, we allocate the annual emissions of these heavy metals in 2010 at a high spatial resolution of 0.5° × 0.5° grid with ArcGIS methodology and surrogate indexes, such as regional population and gross domestic product (GDP). Our results show that the historical emissions of Hg, As, Se, Cd, Cr, Ni, Sb, Mn, Co, Cu, and Zn, during the period of 1949-2012, increased by about 22-128 times at an annual average growth rate of 5.1-8.0 %, reaching about 526.9-22 319.6 t in 2012. Nonferrous metal smelting, coal combustion of industrial boilers, brake and tyre wear, and ferrous metal smelting represent the dominant sources of heavy metal emissions. In terms of spatial variation, the majority of emissions are concentrated in relatively developed regions, especially for the northern, eastern, and southern coastal regions. In addition, because of the flourishing nonferrous metal smelting industry, several southwestern and central-southern provinces play a prominent role in some specific toxic heavy metals emissions, like Hg in Guizhou and As in Yunnan. Finally, integrated countermeasures are proposed to minimize the final toxic heavy metals discharge on account of the current and future demand of energy-saving and pollution reduction in China.

  8. Quantitative analysis of potentially toxic metals in alginates for dental use

    OpenAIRE

    A. S. Braga; A. B.C.E.B. CATIRSE; VAZ, L. G.; A. C.C. Spadaro

    2009-01-01

    Alginate is one the materials most employed in practice to make dental impressions. Substances like zinc, cadmium and lead silicate, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern as regards their toxicity. The most serious chronic effect of oral exposure to c...

  9. Quantitative analysis of potentially toxic metals in alginates for dental use

    OpenAIRE

    VAZ, L. G.; A. C.C. Spadaro; A. B.C.E.B. CATIRSE; A. S. Braga

    2009-01-01

    Alginate is one the materials most employed in practice to make dental impressions. Substances like zinc, cadmium and lead silicate, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern as regards their toxicity. The most serious chronic effect of oral exposure to c...

  10. Heavy and toxic metals in staple foodstuffs and agriproduct from contaminated soils

    International Nuclear Information System (INIS)

    This article presents basic data on the content of Cr, Fe, Ni, Cu, Zn, As, Cd, Sb, Hg, and Pb in staple foodstuffs and agriproducts grown in Russia (Astrakhan region and the town of Belovo) and Egypt (Helwan region). The dependence of the concentration of metals in agriproducts on the content and chemical form of existence in irrigation water and soils is indicated

  11. Heavy and Toxic Metals in Staple Foodstuffs and Agriproduct from Contaminated Soils

    CERN Document Server

    Gorbunov, A V; Kistanov, A A; Lyapunov, S M; Okina, O I; Ramadan, A B

    2002-01-01

    This article presents basic data on the content of Cr, Fe, Ni, Cu, Zn, As, Cd, Sb, Hg, and Pb in staple foodstuffs and agriproduct grown in Russia (Astrakhan region and the town of Belovo) and Egypt (Helwan region). The dependence of the concentration of metals in agriproducts on the content and chemical form of existence in irrigation water and soils is indicated.

  12. EFFECT OF INDUCED TOXIC PATHOLOGICAL EFFECT OF PHARMACEUTICAL AGENTS AND HEAVY METALS ON BROILER BIRDS

    OpenAIRE

    Ganguly Subha

    2013-01-01

    The indiscriminate and injudicious use of second generation fluoroquinolones viz., enrofloxacin produced anemia, leucopenia, hypoglycaemia, hypoproteinemia, increased enzymatic activity and hepatotoxic and nephrotoxic effects in broiler chickens. Exposure to heavy metals results in congestion and hemorrhages in the lungs, tubular degeneration in kidneys and occasional hemorrhages in the brain. The present article was conducted to review the various pharmaceutical, physiological and toxicopath...

  13. Graphene-Based Microbots for Toxic Heavy Metal Removal and Recovery from Water.

    Science.gov (United States)

    Vilela, Diana; Parmar, Jemish; Zeng, Yongfei; Zhao, Yanli; Sánchez, Samuel

    2016-04-13

    Heavy metal contamination in water is a serious risk to the public health and other life forms on earth. Current research in nanotechnology is developing new nanosystems and nanomaterials for the fast and efficient removal of pollutants and heavy metals from water. Here, we report graphene oxide-based microbots (GOx-microbots) as active self-propelled systems for the capture, transfer, and removal of a heavy metal (i.e., lead) and its subsequent recovery for recycling purposes. Microbots' structure consists of nanosized multilayers of graphene oxide, nickel, and platinum, providing different functionalities. The outer layer of graphene oxide captures lead on the surface, and the inner layer of platinum functions as the engine decomposing hydrogen peroxide fuel for self-propulsion, while the middle layer of nickel enables external magnetic control of the microbots. Mobile GOx-microbots remove lead 10 times more efficiently than nonmotile GOx-microbots, cleaning water from 1000 ppb down to below 50 ppb in 60 min. Furthermore, after chemical detachment of lead from the surface of GOx-microbots, the microbots can be reused. Finally, we demonstrate the magnetic control of the GOx-microbots inside a microfluidic system as a proof-of-concept for automatic microbots-based system to remove and recover heavy metals. PMID:26998896

  14. A review of metal accumulation and toxicity in wild mammals. I. Mercury.

    Science.gov (United States)

    Wren, C D

    1986-06-01

    Release of Hg compounds into the environment from point sources has largely been curtailed due to the known impacts of Hg on biological systems. Mercury continues to be released into the environment, however, from nonpoint sources such as combustion of fossil fuels and smelting operations. While the accumulation and toxicity of Hg in aquatic biota, domestic animals, and humans is well documented, relatively little is understood about these processes in wild terrestrial mammals. The purpose of this paper is to review the available literature on Hg levels and toxicity in wild mammals (excluding marine mammals). It is clear that Hg levels are biomagnified within terrestrial food chains, where carnivores greater than omnivores greater than herbivores. Among carnivorous species, Hg levels are generally highest in fish-eating animals. There is usually a high degree of correlation of Hg levels between different animal tissues. The age and sex of an animal appear to influence observed Hg levels, but field data are conflicting for both factors. Tissue Hg levels are affected by location, with significant differences attributable to both local contamination and natural background variability. Experimental studies have shown many mammal species to sensitive to Hg intoxication, but documented incidents of Hg poisoning in wild mammals are rare. Such rarity may be more a function of our inability to observe and demonstrate Hg poisoning in wild populations, rather than an absence of the disease. PMID:3519207

  15. Comparative study of three oligochaete species as indicators of metals in a sediment toxicity bioassay

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, K.; Scheuerman, P.; Lanza, G.; Nelson, D. [East Tennessee State Univ., Johnson City, TN (United States); Brinkhurst, R. [Aquatic Resources Center, Franklin, TN (United States)

    1995-12-31

    Three oligochaete species, Tubifex tubifex, Branchiura sowerbyi and Lumbriculus variegatus, were analyzed for bioaccumulation and reproductive effects from reference sediment spiked with Cd or Cu. Sediment was spiked using the Sediment Suspension method to achieve concentrations of 4.0, 8.0 and 16.0 mg Cd/kg sediment (dry weight) and 25.0, 36.0, 50.0, 100.0 mg Cu/kg sediment (dry weight) . The bioassay was conducted under aerated, static conditions for 28 d at 22.5 C. Reproductive effects consisting of number of cocoons and eggs produced a negative linear regression with increasing Cd concentration. Cocoon volume remained consistent. Cu was more toxic to T. tubifex in this bioassay than results reported by the USEPA using similar concentrations. Lower concentrations of Cu also showed a negative linear regression with reproductive effects showing that oligochaetes could be a feasible indicator organism for sediment toxicity in a standardized ecological impact assay using reproduction as an endpoint.

  16. Threat of the Health Quality of Garden Produces Linked to Pollution by Toxic Metals on Some Gardening Sites of Benin

    Directory of Open Access Journals (Sweden)

    Koumolou Luc

    2012-01-01

    Full Text Available Problem statement: Water and soil are vital resources used in agriculture. Current data establish a link between the pollution of soil, water and public health. For this reason, this study attempted to establish a link between the level of pollution of garden sites in lead (Pb, Cadmium (Cd and Arsenic (As and the health quality of vegetables grown there, through the quality of soil and of the irrigation water. Approach: Composite samples of vegetables, irrigation water and soil taken in the same periods at two garden sites in the city of Cotonou and another one in the village of Aplahoue, were analyzed for Pb, Cd and As by atomic absorption spectrophotometer. The amounts (average ± SD have been compared by the statistical Student p test (T>t = 0.05. Results: The results show that all the vegetables grown on the three sites are differently contaminated with Pb, Cd and As, as well as their irrigation water and the soil. However, the link attempted to be established between pollution of soil, irrigation water and quality of vegetables, could not be obvious, it has been discussed. Soil pollution with toxic metals seems to be of minor importance and does not directly influence the contamination of vegetables Conversely to soil pollution, the levels of contamination of irrigation water by trace metals (Cd and As are much closer to that of vegetables, apart Pb. However, the high urban and atmospheric pressures in Cotonou have significantly influenced the contamination. For, it is in Aplahoue, farming environment, that the lowest amounts of metals in water and in the vegetables have been recorded. Conclusion/Recommendations: There is a risk of contamination in the food chain by heavy metals whose consumption through these gardening products could cause public health problems. Thus, the adoption of reasonable behavior and the development of new technologies are needed to associate food security, economic development, the preservation of the

  17. Daphnia magna's sense of competition: intra-specific interactions (ISI) alter life history strategies and increase metals toxicity.

    Science.gov (United States)

    Gust, Kurt A; Kennedy, Alan J; Melby, Nicolas L; Wilbanks, Mitchell S; Laird, Jennifer; Meeks, Barbara; Muller, Erik B; Nisbet, Roger M; Perkins, Edward J

    2016-08-01

    This work investigates whether the scale-up to multi-animal exposures that is commonly applied in genomics studies provides equivalent toxicity outcomes to single-animal experiments of standard Daphnia magna toxicity assays. Specifically, we tested the null hypothesis that intraspecific interactions (ISI) among D. magna have neither effect on the life history strategies of this species, nor impact toxicological outcomes in exposure experiments with Cu and Pb. The results show that ISI significantly increased mortality of D. magna in both Cu and Pb exposure experiments, decreasing 14 day LC50 s and 95 % confidence intervals from 14.5 (10.9-148.3) to 8.4 (8.2-8.7) µg Cu/L and from 232 (156-4810) to 68 (63-73) µg Pb/L. Additionally, ISI potentiated Pb impacts on reproduction eliciting a nearly 10-fold decrease in the no-observed effect concentration (from 236 to 25 µg/L). As an indication of environmental relevance, the effects of ISI on both mortality and reproduction in Pb exposures were sustained at both high and low food rations. Furthermore, even with a single pair of Daphnia, ISI significantly increased (p < 0.05) neonate production in control conditions, demonstrating that ISI can affect life history strategy. Given these results we reject the null hypothesis and conclude that results from scale-up assays cannot be directly applied to observations from single-animal assessments in D. magna. We postulate that D. magna senses chemical signatures of conspecifics which elicits changes in life history strategies that ultimately increase susceptibility to metal toxicity. PMID:27151402

  18. Toxicity of algal-derived aldehydes to two invertebrate species: Do heavy metal pollutants have a synergistic effect?

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Rebecca L. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)]. E-mail: r.l.taylor@ncl.ac.uk; Caldwell, Gary S. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom); Bentley, Matthew G. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2005-08-15

    The recent discovery of the production of anti-proliferative aldehydes in a variety of microalgal species has lead to considerable investigation into the effects of these toxins on aquatic invertebrates. Studies have, however, rarely considered the impact pollutants may have on grazer responses to algal toxins. In this study, the acute toxicities of five aldehydes to the rotifer Brachionus plicatilis and nauplii of the brine shrimp Artemia salina are examined using immersion assays. In addition, the effect of a representative of these aldehydes in the presence of sub-lethal levels of heavy metals was examined. B. plicatilis generally showed greater sensitivity to the aldehydes than A. salina. The polyunsaturated 2-trans,4-trans-decadienal was the most toxic to both species having 24 h LD{sub 50} values of 7 and 20 {mu}M for B. plicatilis and A. salina, respectively. The remaining aldehydes had different orders of toxicity for the two species with a stronger relationship observed between mortality and aldehyde carbon-chain length for A. salina whereas B. plicatilis mortality showed a stronger dependence on the presence of carbon-carbon double bonds in the aldehydes. The presence of 1 {mu}M of copper sulphate in solutions of decadienal resulted in the reduction of the 24 h LD{sub 50} of decadienal by approximately a third for both species. 1 {mu}M of copper chloride in solutions of decadienal reduced the 24 h LD{sub 50} of decadienal to A. salina nauplii by approximately 11% and 1 {mu}M zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 {mu}M copper sulphate had no significant impact on their subsequent mortality in decadienal. The ecological implications and the possible mechanisms for the action of copper sulphate on the response of organisms to decadienal are discussed.

  19. Toxicity of algal-derived aldehydes to two invertebrate species: Do heavy metal pollutants have a synergistic effect?

    International Nuclear Information System (INIS)

    The recent discovery of the production of anti-proliferative aldehydes in a variety of microalgal species has lead to considerable investigation into the effects of these toxins on aquatic invertebrates. Studies have, however, rarely considered the impact pollutants may have on grazer responses to algal toxins. In this study, the acute toxicities of five aldehydes to the rotifer Brachionus plicatilis and nauplii of the brine shrimp Artemia salina are examined using immersion assays. In addition, the effect of a representative of these aldehydes in the presence of sub-lethal levels of heavy metals was examined. B. plicatilis generally showed greater sensitivity to the aldehydes than A. salina. The polyunsaturated 2-trans,4-trans-decadienal was the most toxic to both species having 24 h LD50 values of 7 and 20 μM for B. plicatilis and A. salina, respectively. The remaining aldehydes had different orders of toxicity for the two species with a stronger relationship observed between mortality and aldehyde carbon-chain length for A. salina whereas B. plicatilis mortality showed a stronger dependence on the presence of carbon-carbon double bonds in the aldehydes. The presence of 1 μM of copper sulphate in solutions of decadienal resulted in the reduction of the 24 h LD50 of decadienal by approximately a third for both species. 1 μM of copper chloride in solutions of decadienal reduced the 24 h LD50 of decadienal to A. salina nauplii by approximately 11% and 1 μM zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 μM copper sulphate had no significant impact on their subsequent mortality in decadienal. The ecological implications and the possible mechanisms for the action of copper sulphate on the response of organisms to decadienal are discussed

  20. An exploration of spatial human health risk assessment of soil toxic metals under different land uses using sequential indicator simulation.

    Science.gov (United States)

    Huang, Jin-Hui; Liu, Wen-Chu; Zeng, Guang-Ming; Li, Fei; Huang, Xiao-Long; Gu, Yan-Ling; Shi, Li-Xiu; Shi, Ya-Hui; Wan, Jia

    2016-07-01

    A modified method was proposed which integrates the spatial patterns of toxic metals simulated by sequential indicator simulation, different exposure models and local current land uses extracted by remote-sensing software into a dose-response model for human health risk assessment of toxic metals. A total of 156 soil samples with a various land uses containing farm land (F1-F25), forest land (W1-W12) and residential land (U1-U15) were collected in a grid pattern throughout Xiandao District (XDD), Hunan Province, China. The total Cr and Pb in topsoil were analyzed. Compared with Hunan soil background values, the elevated concentrations of Cr were mainly located in the east of XDD, and the elevated concentrations of Pb were scattered in the areas around F1, F6, F8, F13, F14, U5, U14, W2 and W11. For non-carcinogenic effects, the hazard index (HI) of Cr and Pb overall the XDD did not exceed the accepted level to adults. While to children, Cr and Pb exhibited HI higher than the accepted level around some areas. The assessment results indicated Cr and Pb should be regarded as the priority pollutants of concern in XDD. The first priority areas of concern were identified in region A with a high probability (>0.95) of risk in excess of the accepted level for Cr and Pb. The areas with probability of risk between 0.85 and 0.95 in region A were identified to be the secondary priority areas for Cr and Pb. The modified method was proved useful due to its improvement on previous studies and calculating a more realistic human health risk, thus reducing the probability of excessive environmental management. PMID:27045920

  1. Effect of heavy metals induced toxicity on metabolic biomarkers in common carp (Cyprinus Carpio L.

    Directory of Open Access Journals (Sweden)

    Vinodhini Rajamanickam

    2008-02-01

    Full Text Available This research paper presents the pathological effects of a sub-lethal concentration of heavy metals (cadmium, lead, nickel, and chromium on common carp (Cyprinus carpio L.. Total protein and levels of alkaline phosphatase (ALP, alanine aminotransferase (ALT, aspartate aminotransferase (AST and lactate dehydrogenase (LDH in the liver tissue were measured. Compared with the control group a significant decrease of total protein (p < 0.001 was ascertained in the experimental group. The ALP on the other hand was significantly higher (p < 0.001. The values of ALT, AST, and LDH significantly decreased in the first day and then progressively increased afterwards (p < 0.001. The above results on the biochemical profile indicate marked hepatotoxic effects of heavy metals in common carp.

  2. Toxic metals in urban runoff: physico-chemical mobility assessment using speciation schemes

    OpenAIRE

    Flores-Rodrîguez, Julio; Bussy, Anne-Laure; Thevenot, Daniel,

    1994-01-01

    Physico-chemical characterization of lead, zinc and cadmium has been carried out on eight samples from both separate and combined sewers. Dissolved and particulate total metal levels have been determined. A speciation scheme has been used ta further divide these phases in two dissolved fractions, bioavailable and stable, and five particulate fractions, ion-exchangeable, acid-soluble, reducible, oxidizable and residual. TotaJ dissolved lead concentrations were found ta be largely below Europea...

  3. Dynamics of toxic heavy metals in different compartments of a highly urbanized closed aquatic system.

    Science.gov (United States)

    Gupta, Bina; Kumar, Rahul; Rani, Manviri; Agarwal, Tripti

    2012-03-01

    This paper deals with the dynamics of chromium, nickel, copper and lead among the different components namely water, surface sediments, submerged and free floating macrophytes and fish of the twin manmade lakes, Upper and Lower lakes, of Bhopal (M.P., India). Some basic parameters of water and sediment have also been studied. The basin of the lake system is densely populated and the water is used for various purposes including drinking. Ni and Pb along with nitrate in both lakes are significantly higher than the drinking water quality criteria of USEPA. The concentration of the metals in the sediments is noticeably higher than that present in the adjoining rock, particularly Ni and Pb. There is a significant uptake of metals by the macrophytes (Eichhornia crassipes and Hydrilla verticillata) and fish (Labeo rohita and Oreochromis niloticus) mainly in summer. The fish of Lower lake (O. niloticus) is unfit for human consumption. The data have been statistically treated. Principle component analysis and cluster analysis were performed to define the origin of metals and to assess the relationship among the sites. Overall the Lower lake is more polluted than the Upper lake. In aggregate, the lake system is under an environmental stress due to certain practices. PMID:22290427

  4. Effects of sucrose and sorbitol on cement-based stabilization/solidification of toxic metal waste.

    Science.gov (United States)

    Zhang, Linghong; Catalan, Lionel J J; Larsen, Andrew C; Kinrade, Stephen D

    2008-03-01

    The effects of sucrose or sorbitol addition on the hydration, unconfined compressive strength and leachability of Portland cement pastes containing 1% Pb and 1% Zn were studied as a function of time. Whereas Pb and Zn were found to shorten the time to achieve maximum hydration of Portland cement, the combination of these metals with 0.15 wt% sucrose or 0.40 wt% sorbitol retarded the setting of cement by at least 7 and 28 days, respectively, without affecting the strength at 56 days. The leachability of Pb and Zn evaluated by the TCLP 1311 protocol at 56 and 71 days was slightly reduced or unchanged by the addition of sucrose or sorbitol. SEM-EDS and XRD analyses revealed that ettringite precipitation was favored whereas the formation of CSH gel, which accounts for most of the strength of hydrated cement, was delayed in cement pastes containing both metals and sucrose or sorbitol. These results indicate that controlled additions of sucrose or sorbitol can add flexibility to the handling of cement-treated metal waste, particularly when it needs to be transported by truck or pipeline between the treatment plant and the disposal site, without affecting its long-term performance. PMID:17629400

  5. Dynamics of metal availability and toxicity in historically polluted floodplain sediments.

    Science.gov (United States)

    van der Geest, Harm G; León Paumen, Miriam

    2008-12-01

    Many floodplains contain high concentrations of sediment associated contaminants that might be subjected to large changes in terms of mobility, transformation and bioavailability. Therefore, this study describes 1) changes in the redox conditions and the mobility of metals in artificially uncovered polluted floodplain sediments, 2) metal uptake by organisms and 3) colonization, succession and functioning of benthic algae on these sediments. Flooding caused long term changes in redox potential (Eh) profiles. In top layers strong gradients in redox potential established quickly, while in deeper layers changes occurred more gradually. The availability of copper as measured by Diffusive Gradients in Thinfilms (DGT) showed a consistent relationship with fluctuations in Eh. However, this relationship was restricted to deeper layers in the sediment. Within 1 week high amounts of total copper were immobilized. Differences in total copper concentrations between polluted and clean sediments became only partially apparent when comparing the available copper fraction (DGT-Cu). Introduced Tubifex shows only marginal differences in levels of accumulated Cu. Colonization, growth and succession of algal communities on polluted sediments was not impaired, most likely due to low bioavailability. It is concluded that changing environmental conditions, such as flooding, can result in stable chemical conditions with low a availability of metals and hence in a diminution of actual ecological risks. PMID:18644615

  6. Quantitative assessment of atmospheric emissions of toxic heavy metals from anthropogenic sources in China: historical trend, spatial variation distribution, uncertainties and control policies

    Directory of Open Access Journals (Sweden)

    H. Z. Tian

    2015-04-01

    Full Text Available Anthropogenic atmospheric emissions of typical toxic heavy metals have received worldwide concerns due to their adverse effects on human health and the ecosystem. By determining the best available representation of time-varying emission factors with S-shape curves, we established the multiyear comprehensive atmospheric emission inventories of 12 typical toxic heavy metals (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu and Zn from primary anthropogenic activities in China for the period of 1949–2012 for the first time. Further, we allocated the annual emissions of these heavy metals in 2010 at a high spatial resolution of 0.5° × 0.5° grid with ArcGIS methodology and surrogate indexes, such as regional population and gross domestic product (GDP. Our results show that the historical emissions of Hg, As, Se, Cd, Cr, Ni, Sb, Mn, Co, Cu and Zn during the period of 1949–2012, have been increased by about 22–128 times at an annual average growth rate of 5.1–8.0%, amounting to about 79 570 t in 2012. Nonferrous metal smelting, coal combustion of industrial boilers, brake and tyre wear, and ferrous metals smelting represent the dominant sources for Hg / Cd, As / Se / Pb / Cr / Ni / Mn / Co, Sb / Cu, and Zn, respectively. In terms of spatial variation, the majority of emissions were concentrated in relatively developed regions, especially for the northern, eastern and southern coastal regions. In addition, because of the flourishing nonferrous metals smelting industry, several southwestern and central-southern provinces play a prominent role in some specific toxic heavy metals emissions, like Hg in Guizhou and As in Yunnan. Finally, integrated countermeasures are proposed to minimize the final toxic heavy metals discharge on accounting of the current and future demand of energy-saving and pollution reduction in China.

  7. Molecular mechanisms of the epithelial transport of toxic metal ions, particularly mercury, cadmium, lead, arsenic, zinc and copper. Progress report, January 1, 1980-December 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Wasserman, R H

    1980-01-01

    Investigations were continued to elucidate the mode of transepithelial transport of toxic metal ions across the gastrointestinal tract, as well as their interactions with biological processes and other metal ions. All experimental details that are either published, submitted for publication or in press during this report period are included in the Appendix. Primary attention for this report has been given to the intestinal absorption of lead and its interaction with other biological moieties.

  8. Molecular mechanisms of the epithelial transport of toxic metal ions, particularly mercury, cadmium, lead, arsenic, zinc and copper. Progress report, January 1, 1980-December 31, 1980

    International Nuclear Information System (INIS)

    Investigations were continued to elucidate the mode of transepithelial transport of toxic metal ions across the gastrointestinal tract, as well as their interactions with biological processes and other metal ions. All experimental details that are either published, submitted for publication or in press during this report period are included in the Appendix. Primary attention for this report has been given to the intestinal absorption of lead and its interaction with other biological moieties

  9. Bioaccumulation of Trace Metals in Mussel (Mytilus galloprovincialis from Mali Ston Bay during DSP Toxicity Episodes

    Directory of Open Access Journals (Sweden)

    Ivana Ujević

    2015-07-01

    Full Text Available The Croatian National Monitoring Program revealed the presence of Diarrhetic Shellfish Poisoning (DSP toxicity in Mediterranean blue mussel (Mytilus galloprovincialis from breeding farms in southern Adriatic Sea through January to June 2011. The mouse bioassay tests (MBA; at the time the official method for DSP toxins were accompanied by atypical symptomatology in the animals and this caused doubts about the assay results. Consequently, in parallel studies reported here, the concentration of Cd, Cr, Cu, Ni, Pb and Zn in soft tissue of DSP positive and negative mussels samples was determined. Cd, Cr, Zn and Ni show higher values in approximately 75% of the DSP positive samples, whereas for Pb and Cr the values were 26% and 34%, respectively. This trend was unchanged during the whole observation period.

  10. Protection against heavy metal toxicity by mucous and scales in fish

    Energy Technology Data Exchange (ETDEWEB)

    Coello, W.F.; Khan, M.A.Q. [Univ. of Illinois, Chicago, IL (United States). Dept. of Biological Sciences

    1995-12-31

    Fingerlings of three freshwater fish species showed differences in susceptibility to lethality of 250 mg/L lead suspension or lead nitrate solution in water. Among these the large mouth bass Micropterus salmoides seemed to be more tolerant than green sunfish Lepomis cyanellus and goldfish Carassius auratus. Mucous from large mouth bass, when added to jars containing lead, lowered the toxicity of lead to sunfish and goldfish. Adding scales, especially if these were pretreated with an alkaline solution of cysteine and glycine, made all these species become tolerant to otherwise lethal concentrations of lead nitrate. The scales and mucous together buffered the acidity of lead nitrate and mercuric nitrate solution and sequestered hydrogen ions and lead and mercury from water and then settled to the bottom of jars. Scales of younger fingerling were more efficient than those of older ones.

  11. Improvement of heavy metal stress and toxicity assays by coupling a transgenic reporter in a mutant nematode strain

    International Nuclear Information System (INIS)

    Previous studies have demonstrated that wild type Caenorhabditis elegans displays high sensitivity to heavy metals in a lethality test at a level comparable to that of other bioindicator organisms. Taking advantage of the genetics of this model organism, we have tested a number of mutant strains for enhanced sensitivity in heavy metal induced lethality and stress response. These mutants are defective in genes controlling dauer formation, longevity or response to reactive oxygen species (ROS). Among the tested mutants, a double mutant daf-16 unc-75 strain was identified to have superior sensitivity. It has a 6-, 3- and 2-fold increase in sensitivity to cadmium, copper and zinc, respectively, as compared with that of wild type animals. When a fluorescent reporter transgene was coupled with this double mutant for stress detection, a 10-fold enhancement of sensitivity to cadmium over the wild type strain was observed. These transgenic animals, superior to most of the model organisms currently used in bioassays for environmental pollutants, offer a fast and economic approach to reveal the bioavailability of toxic substance in field samples. This study also demonstrates that combination of genetic mutations and transgenesis is a viable approach to identify sensitive indicator animals for environmental monitoring

  12. Toxic effect of zinc nanoscale metal-organic frameworks on rat pheochromocytoma (PC12) cells in vitro

    International Nuclear Information System (INIS)

    Highlights: • Metal-organic frameworks (MOFs) represent a newborn family of hybrid materials. • MOFs have already shown promise in a number of biological applications. • The biological applications of MOFs raise concerns for potential cytotoxicity. • Substantial information about MOF's neurotoxicity is still quite scarce. • This study reveals for the first time the interaction of MOFs with neural cells. - Abstract: Metal-organic frameworks (MOFs) possess unique properties desirable for delivery of drugs and gaseous therapeutics, but their uncharacterized interactions with cells raise increasing concerns of their safety in such biomedical applications. We evaluated the adverse effects of zinc nanoscale MOFs on the cell morphology, cytoskeleton, cell viability and expression of neurotrophin signaling pathway-associated GAP-43 protein in rat pheochromocytoma PC12 cells. At the concentration of 25 μg/ml, zinc MOFs did not significantly affect morphology, viability and membrane integrity of the cells. But at higher concentrations (over 100 μg/ml), MOFs exhibited a time- and concentration-dependent cytotoxicity, indicating their entry into the cells via endocytosis where they release Zn2+ into the cytosol to cause increased intracellular concentration of Zn2+. We demonstrated that the toxicity of MOFs was associated with a disrupted cellular zinc homeostasis and down-regulation of GAP-43 protein, which might be the underlying mechanism for the improved differentiation in PC12 cells. These findings highlight the importance of cytotoxic evaluation of the MOFs before their biomedical application

  13. Toxic effect of zinc nanoscale metal-organic frameworks on rat pheochromocytoma (PC12) cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Fei, E-mail: paper_mail@126.com [Department of Pharmacy, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Yang, Baochun; Cai, Jing [Department of Pharmacy, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Jiang, Yaodong [Department of Urology, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Xu, Jun [Department of Health Economy Administration, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Wang, Shan [Department of Pharmacy, Winthrop University Hospital, Mineola, NY 11501 (United States)

    2014-04-01

    Highlights: • Metal-organic frameworks (MOFs) represent a newborn family of hybrid materials. • MOFs have already shown promise in a number of biological applications. • The biological applications of MOFs raise concerns for potential cytotoxicity. • Substantial information about MOF's neurotoxicity is still quite scarce. • This study reveals for the first time the interaction of MOFs with neural cells. - Abstract: Metal-organic frameworks (MOFs) possess unique properties desirable for delivery of drugs and gaseous therapeutics, but their uncharacterized interactions with cells raise increasing concerns of their safety in such biomedical applications. We evaluated the adverse effects of zinc nanoscale MOFs on the cell morphology, cytoskeleton, cell viability and expression of neurotrophin signaling pathway-associated GAP-43 protein in rat pheochromocytoma PC12 cells. At the concentration of 25 μg/ml, zinc MOFs did not significantly affect morphology, viability and membrane integrity of the cells. But at higher concentrations (over 100 μg/ml), MOFs exhibited a time- and concentration-dependent cytotoxicity, indicating their entry into the cells via endocytosis where they release Zn{sup 2+} into the cytosol to cause increased intracellular concentration of Zn{sup 2+}. We demonstrated that the toxicity of MOFs was associated with a disrupted cellular zinc homeostasis and down-regulation of GAP-43 protein, which might be the underlying mechanism for the improved differentiation in PC12 cells. These findings highlight the importance of cytotoxic evaluation of the MOFs before their biomedical application.

  14. Determination of atmospheric concentration of toxic metals along urban motorways in two Nigerian cities using TXRF technique

    International Nuclear Information System (INIS)

    The application of gravimetric sampling for PM2.5, PM10 and TSP along traffic corridors in Lagos and Ile-Ife, Nigeria, followed by the TD-XRF analysis of trace elements in the traffic corridors is reported. Results show the TD-XRF as a valuable tool for assessing heavy metal pollution in urban and rural areas. More than 15 trace elements were analysed in the urban traffic corridors. The study indicates that the transport sector is still contributing significantly to urban air quality deteriorations. The toxicity potentials (TP) for SPM and lead (Pb), determined for sites sampled in the two cities were high for all the sites in Lagos and all locations in Ile-Ife except for one residential site. For this site a TP value of 0.43 was obtained. For lead (Pb) the TP values were observed to be high for all the sites in Lagos and low (less than unity) for all the sites in Ile-Ife except for one commercial site. The results suggest the need for improved management of the transport sector, possibly through the introduction of integrated transport system to reduce the current over-dependence on road transport. The results for heavy metal pollution also suggests the need for gradual phase-out of leaded gasoline in Nigeria. (author)

  15. Assessing the impact of organic and inorganic amendments on the toxicity and bioavailability of a metal-contaminated soil to the earthworm Eisenia andrei.

    Science.gov (United States)

    González, Verónica; Díez-Ortiz, María; Simón, Mariano; van Gestel, Cornelis A M

    2013-11-01

    Metal-contaminated soil, from the El Arteal mining district (SE Spain), was remediated with organic (6% compost) and inorganic amendments (8% marble sludge) to reduce the mobility of metals and to modify its potential environmental impact. Different measures of metal bioavailability (chemical analysis; survival, growth, reproduction and bioaccumulation in the earthworm Eisenia andrei), were tested in order to evaluate the efficacy of organic and inorganic amendments as immobilizing agents in reducing metal (bio)availability in the contaminated soil. The inorganic amendment reduced water and CaCl2-extractable concentrations of Cd, Pb, and Zn, while the organic amendment increased these concentrations compared to the untreated soil. The inorganic treatment did not significantly reduce toxicity for the earthworm E. andrei after 28 days exposure. The organic amendment however, made the metal-contaminated soil more toxic to the earthworms, with all earthworms dying in undiluted soil and completely inhibiting reproduction at concentrations higher than 25%. This may be due to increased available metal concentrations and higher electrical conductivity in the compost-amended soil. No effects of organic and inorganic treatments on metal bioaccumulation in the earthworms were found and metal concentrations in the earthworms increased with increasing total soil concentrations. PMID:23677751

  16. Physiological profiling of indigenous aquatic microbial communities to determine toxic effects of metals

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, R.M.; Colwell, F.S. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States); Garland, J.L. [Dynamac, Kennedy Space Center, FL (United States)

    1997-11-01

    Conventional bioassays for environmental assessment frequently rely on nonindigenous single species. The authors employed an assay in which whole environmental samples were distinguished by the ability of the native heterotrophic microbial communities to oxidize 95 different sole carbon sources generating a community-level physiological profile (CLPP). The average metabolic response (AMR) to the 95 variables defining the CLPP was used in laboratory bioassay studies with copper to construct dose-response curves over several different periods of exposure: 1 h (acute), 1 d, 2 d, and 4 d. The acute dose-response of Snake River bacterioplankton communities measured by AMR was compared to the dose-response of Photobacterium phosphoreum (used in the Microtox test) and a proprietary mixed consortia (used in the Polytox test). In laboratory bioassay studies, CLPP, AMR exhibited acute dose-response behavior over a greater range in copper concentrations and with less variability (per dose) than Microtox and Polytox. The acute sensitivity of CLPP AMR to copper was roughly equal to Microtox and much greater than Polytox. After a longer exposure (1 d) to copper, Snake River communities became more sensitive to copper but no additional effect was observed when the exposure was increases to 2 and 4 d. Snake River communities pre-exposed to copper (1 mg/L) for 4 d prior to acute dose-response experiments showed no difference in AMR with respect to doses up to 10 mg/L, indicating the ability of the assay to detect adaptation. Several metal-contaminated streams in Idaho were used to field validate the CLPP approach for detecting impacts of metals in the environment. The response profiles of the bacterioplankton from two downstream sites receiving metal laden mine drainage were compared to those from reference sites upstream and further downstream of the location receiving the mine drainage.

  17. A test of the additivity of acute toxicity of binary-metal mixtures of ni with Cd, Cu, and Zn to Daphnia magna, using the inflection point of the concentration-response curves.

    Science.gov (United States)

    Traudt, Elizabeth M; Ranville, James F; Smith, Samantha A; Meyer, Joseph S

    2016-07-01

    Mixtures of metals are often present in surface waters, leading to toxicity that is difficult to predict. To provide data for development of multimetal toxicity models, Daphnia magna neonates were exposed to individual metals (Cd, Cu, Ni, Zn) and to binary combinations of those metals in standard 48-h lethality tests conducted in US Environmental Protection Agency moderately hard reconstituted water with 3 mg dissolved organic carbon (DOC)/L added as Suwannee River fulvic acid. Toxicity tests were performed with mixtures of Ni and 1) Cd, which is considerably more toxic than Ni; 2) Cu, which is less toxic than Cd but more toxic than Ni; and 3) Zn, which has a toxicity threshold similar to Ni. For each combination of metals in the binary mixtures, the concentration of 1 metal was held constant while the second metal was varied through a series that ranged from nonlethal to lethal concentrations; then the roles of the metals were reversed. Inflection points of the concentration-response curves were compared to test for additivity of toxicity. Sublethal concentrations of Ni caused less-than-additive toxicity with Cd, slightly less-than-additive toxicity with Zn, and greater-than-additive toxicity with Cu. One explanation of these results might be competition among the metals for binding to biological ligands and/or dissolved organic matter. Therefore, models might have to incorporate sometimes competing chemical interactions to accurately predict metal-mixture toxicity. Environ Toxicol Chem 2016;35:1843-1851. © 2015 SETAC. PMID:26681657

  18. Integrated chemical/biological treatment of paint stripper mixed waste: Metals toxicity and separation

    International Nuclear Information System (INIS)

    The DOE complex has generated vast quantities of complex heterogeneous mixed wastes. Paint stripper waste (PSW) is a complex waste that arose from decontamination and decommissioning activities. It contains paint stripper, cheesecloth, cellulose-based paints with Pb and Cr, and suspect Pu. Los Alamos National Laboratory has 150--200 barrels of PSW and other national laboratories such as Rocky Flats Plant have many more barrels of heterogeneous waste. Few technologies exist that can treat this complex waste. Our approach to solving this problem is the integration of two established technologies: biodegradation and metals chelation

  19. Effects of untreated hospital effluents on the accumulation of toxic metals in sediments of receiving system under tropical conditions: case of South India and Democratic Republic of Congo.

    Science.gov (United States)

    Mubedi, Josué Ilunga; Devarajan, Naresh; Le Faucheur, Séverine; Mputu, John Kayembe; Atibu, Emmanuel K; Sivalingam, Periyasamy; Prabakar, Kandasamy; Mpiana, Pius T; Wildi, Walter; Poté, John

    2013-10-01

    Physicochemical and ecotoxicological analyses have been performed to assess the quality of sediments receiving untreated hospital effluents from Indian and Democratic Republic of Congo (DRC) hospitals. The sediments were collected monthly and characterized for grain size, organic matter, total organic carbon, total carbon, nitrogen, phosphorus, toxic metals and ecotoxicity. The results highlight the high concentration of toxic metals from the Indian hospital effluent receiving systems, especially for Cr, Cu, As, Zn and Hg. On the other hand, the metal concentrations in the sediment receiving system from DRC are low (e.g. maximum Hg and Zn concentration were 0.46 and 48.84 mg kg(-1) respectively). Ostracods exposed to sediment samples H2 (September month sample) and H3 (June and September month samples) were found dead after 6d of exposure whereas the higher mortality rate for Congo sediments was 23% but was accompanied with 33 ± 7% of growth inhibition. The results of this study show the variation of sediment composition on toxic metal levels as well as toxicity related to both, the type of hospitals and the sampling period. Additionally, hospital effluent disposal practices at the study sites can lead to the pollution of water resources and may generate risks for aquatic organisms and human health. PMID:23816453

  20. Association of toxic and essential metals with atopy markers and ventilatory lung function in women and men

    International Nuclear Information System (INIS)

    The association of age, smoking, alcohol, superoxide dismutase (SOD), glutathione peroxidase (GPx), blood lead (BPb) and cadmium (BCd) levels, and serum levels of copper (SCu), zinc (SZn) and selenium (SSe) with atopic status and ventilatory function was examined in the groups of 166 women and 50 men with no occupational exposure to metals or other xenobiotics. Markers of atopy included serum total IgE, skin prick test (SPT) to common inhalatory allergens, non-specific nasal reactivity (NNR) and non-specific bronchial reactivity (NBR). Parameters of ventilatory function included forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1). Significantly higher BPb, SZn, IgE and prevalence of positive SPT, and lower SCu and NNR was found in men than in women. Fifteen women taking female sex hormones (HT) had significantly higher SCu than women without HT. Regression models showed significant inverse associations between IgE and SCu (P = 0.021) and NNR and SCu (P = 0.044) in women. When excluding women with HT, the association of SCu and total IgE became of borderline significance (P = 0.051), association between SCu and NNR disappeared, and significant positive association between total IgE and BPb emerged (P = 0.046). In men, significant inverse association was found between positive SPT and SSe, and between NBR and SSe. A decrease in FVC% and FEV1% was associated with an increase in smoking intensity (P < 0.001) and a decrease in SZn (P = 0.043 and P = 0.053, respectively). These results were observed at the levels of the metals comparable to those in general populations worldwide. The observed differences between men and women may partly be explained by different levels of relevant toxic and essential metals, and their combination. The role of female HT in associations of atopy markers and SCu should be further investigated

  1. Design and Development of Biosensors for the Detection of Heavy Metal Toxicity

    Directory of Open Access Journals (Sweden)

    Graziella L. Turdean

    2011-01-01

    Full Text Available Many compounds (including heavy metals, HMs used in different fields of industry and/or agriculture act as inhibitors of enzymes, which, as consequence, are unable to bind the substrate. Even if it is not so sensitive, the method for detecting heavy metal traces using biosensors has a dynamic trend and is largely applied for improving the “life quality”, because of biosensor's sensitivity, selectivity, and simplicity. In the last years, they also become more and more a synergetic combination between biotechnology and microelectronics. Dedicated biosensors were developed for offline and online analysis, and also, their extent and diversity could be called a real “biosensor revolution”. A panel of examples of biosensors: enzyme-, DNA-, imuno-, whole-cell-based biosensors were systematised depending on the reaction type, transduction signal, or analytical performances. The mechanism of enzyme-based biosensor and the kinetic of detection process are described and compared. In this context, is explainable why bioelectronics, nanotechnology, miniaturization, and bioengineering will compete for developing sensitive and selective biosensors able to determine multiple analytes simultaneously and/or integrated in wireless communications systems.

  2. Professional illnesses in miners caused by heavy metals and toxic substances

    Directory of Open Access Journals (Sweden)

    Veličkova N.

    2013-01-01

    Full Text Available The exposure of humans in an environment contaminated with heavy metals is associated with many diseases, characterized by pathological changes in the respiratory tract, lung function deterioration. The results of the research, conducted with miners working in the “Sasa” lead and zinc mine, were focused on validating the existing professional risk. Most affected are the miners engaged in drilling head and ore. Disease was verified by analysis of acute symptoms. According to the time of exposure, disease symptoms were most frequent after exposure from 1 to 3 years. This indicates that a short span of exposure can be dangerous for some organs, depending on individual hypersensitivity. The most common lung diseases in exposed workers are, chronic bronchitis and tracheitis, chronic obstructive lung disease, pneumoconiosis and silicosis. The multidisciplinary elaboration of the topic, suggests the need for a more serious approach to this important phenomenon (ecotoxicological impact of heavy metals in exposed workers, and also is a specific model that is capable of application and in other related research.

  3. Toxicity of two pulsed metal exposures to Daphnia magna: relative effects of pulsed duration-concentration and influence of interpulse period.

    Science.gov (United States)

    Hoang, Tham C; Gallagher, Jeffrey S; Tomasso, Joseph R; Klaine, Stephen J

    2007-11-01

    Aquatic organisms living in surface waters experience fluctuating contaminant exposures that vary in concentration, duration, and frequency. This study characterized the role of pulsed concentration, pulsed duration, and the interval between pulses on the toxicity of four metals (Cu, Zn, Se, and As) to Daphnia magna. During 21-d toxicity tests, neonatal D. magna were exposed to single or double pulses. Pulsed concentrations and durations ranged from 32 to 6000 microg/L and 8 to 96 h, respectively. Intervals between two pulses ranged from 24 to 288 h. Mortality, growth, and reproduction were characterized for exposures. For single-pulse exposures of Cu and As, metal concentration had a stronger effect on survival of D. magna than did pulsed duration: pulses with 2X concentration and 1Y duration resulted in more mortality than did pulses with 1X concentration and 2Y duration. In contrast, effects of pulsed duration were stronger than metal concentration for Zn. However, the effects of duration and concentration were similar for Se. The relative effects of pulsed concentration and duration found in the present study revealed that the common method using area under the curve (AUC = concentration x duration) may not always accurately estimate environmental risk from metals (e.g., for Cu, Zn, As). In addition, the occurrence of delayed mortality in the present study revealed that using continuous exposure bioassays might underestimate metal toxicity to aquatic biota. For double-pulse exposures, the toxicity of the second pulse was influenced by the first pulse for all four metals. This influence was dependent on the pulsed concentration and duration and the interval between pulses. Further, toxicity caused by the second pulse decreased as the time between the exposures increased. For all four metals, there existed an interval great enough that the toxicity of the two pulses was independent. This would result in less toxicity for multiple exposures than continuous

  4. METAL-CONTAINING CONJUGATED POLYMERS AS FLUORESCENT CHEMOSENSORS IN THE DETECTION OF TOXICANTS.

    Science.gov (United States)

    Fegley, Megan E A; Pinnock, Sherryllene S; Malele, Catherine N; Jones, Wayne E

    2012-02-15

    Fluorescent conjugated polymers have received a great deal of recent interest due to their ability to act as chemosensors to detect various chemical species in both environmental and biological systems with sensitivity and selectivity. Examples from the literature include polymer chemosensors that operate on either fluorescence "turn-on" or "turn-off" as mechanisms of sensor response. These responses can be related to either photoinduced electron transfer or electronic energy transfer mechanisms. Recently, a series of metal-containing polymers or metallopolymers have been explored by various research groups for their use as chemosensors. In many cases, these metallopolymers have been shown to be more sensitive and selective for specific chemical species. This review focuses on fluorescent conjugated polymers as chemosensors, with a specific concentration on recent advances in metallopolymer chemosensors. PMID:22711916

  5. Protection against heavy metal toxicity by mucus and scales in fish.

    Science.gov (United States)

    Coello, W F; Khan, M A

    1996-03-01

    Fingerlings of three freshwater fish showed differences in susceptibility to lethality of 250 mg/L lead suspension or lead nitrate solution in water. Among these, the largemouth bass (Micropterus salmoides) was more tolerant than green sunfish (Lepomis cyanellus) and goldfish (Carassius auratus). The addition of mucus from largemouth bass, when added to jars containing lead, increased the LT-50 value (time to kill 50% of fingerling exposed to 250 mg/L lead) in green sunfish and goldfish. However, adding scales, especially if the scales were treated with an alkaline solution of cysteine and glycine, made all of these species tolerant to otherwise lethal concentrations of lead or mercury. The scales buffered the pH of lead nitrate solution as well as removed lead (and mercury) from water (by settling down at the bottom after sequestering lead). Scales of younger fingerlings of largemouth bass were more efficient in chelating heavy metals than those of older ones. PMID:8854966

  6. Rapid screening of aquatic toxicity of several metal-based nanoparticles using the MetPLATE Trade-Mark-Sign bioassay

    Energy Technology Data Exchange (ETDEWEB)

    Pokhrel, Lok R.; Silva, Thilini [Department of Environmental Health, College of Public Health, East Tennessee State University, Johnson City, TN 37614 (United States); Dubey, Brajesh, E-mail: bdubey@uoguelph.ca [Environmental Engineering, School of Engineering, University of Guelph, 50 Stone Road East, Guelph, Ontario (Canada); El Badawy, Amro M. [Department of Civil and Environmental Engineering, University of Cincinnati, Cincinnati, OH (United States); Tolaymat, Thabet M. [USEPA, Office of Research and Development, National Risk Management Laboratory, 26 West Martin Luther King Drive, Cincinnati, OH 45224 (United States); Scheuerman, Phillip R. [Department of Environmental Health, College of Public Health, East Tennessee State University, Johnson City, TN 37614 (United States)

    2012-06-01

    Current understanding of potential toxicity of engineered nanomaterials to aquatic microorganisms is limited for risk assessment and management. Here we evaluate if the MetPLATE Trade-Mark-Sign test can be used as an effective and rapid screening tool to test for potential aquatic toxicity of various metal-based nanoparticles (NPs). The MetPLATE bioassay is a heavy metal sensitive test based on {beta}-galactosidase activity in Escherichia coli. Five different types of metal-based NPs were screened for toxicity: (1) citrate coated nAg (Citrate-nanosilver), (2) polyvinylpyrrolidone coated nAg (PVP-nAg), (3) uncoated nZnO, (4) uncoated nTiO{sub 2} and (5) 1-Octadecylamine coated CdSe Quantum Dots (CdSe QDs); and compared with their corresponding ionic salt toxicity. Citrate-nAg was further fractionated into clean Citrate-nAg, unclean Citrate-nAg and permeate using a tangential flow filtration (TFF) system to eliminate residual ions and impurities from the stock Citrate-nAg suspension and also to differentiate between ionic- versus nano-specific toxicity. Our results showed that nAg, nZnO and CdSe QDs were less toxic than their corresponding ionic salts tested, while nano- or ionic form of TiO{sub 2} was not toxic as high as 2.5 g L{sup -1} to the MetPLATE Trade-Mark-Sign bacteria. Although coating-dependent toxicity was noticeable between two types of Ag NPs evaluated, particle size and surface charge were not adequate to explain the observed toxicity; hence, the toxicity appeared to be material-specific. Overall, the toxicity followed the trend: CdCl{sub 2} > AgNO{sub 3} > PVP-nAg > unclean Citrate-nAg > clean Citrate-nAg > ZnSO{sub 4} > nZnO > CdSe QDs > nTiO{sub 2}/TiO{sub 2}. These results indicate that an evaluation of {beta}-galactosidase inhibition in MetPLATE Trade-Mark-Sign E. coli can be an important consideration for rapid screening of metal-based NP toxicity, and should facilitate ecological risk assessment of these emerging contaminants. - Highlights

  7. Protection against Mitochondrial and Metal Toxicity Depends on Functional Lipid Binding Sites in ATP13A2

    Directory of Open Access Journals (Sweden)

    Shaun Martin

    2016-01-01

    Full Text Available The late endo-/lysosomal P-type ATPase ATP13A2 (PARK9 is implicated in Parkinson’s disease (PD and Kufor-Rakeb syndrome, early-onset atypical Parkinsonism. ATP13A2 interacts at the N-terminus with the signaling lipids phosphatidic acid (PA and phosphatidylinositol (3,5 bisphosphate (PI(3,5P2, which modulate ATP13A2 activity under cellular stress conditions. Here, we analyzed stable human SHSY5Y cell lines overexpressing wild-type (WT or ATP13A2 mutants in which three N-terminal lipid binding sites (LBS1–3 were mutated. We explored the regulatory role of LBS1–3 in the cellular protection by ATP13A2 against mitochondrial stress induced by rotenone and found that the LBS2-3 mutants displayed an abrogated protective effect. Moreover, in contrast to WT, the LBS2 and LBS3 mutants responded poorly to pharmacological inhibition of, respectively, PI(3,5P2 and PA formation. We further demonstrate that PA and PI(3,5P2 are also required for the ATP13A2-mediated protection against the toxic metals Mn2+, Zn2+, and Fe3+, suggesting a general lipid-dependent activation mechanism of ATP13A2 in various PD-related stress conditions. Our results indicate that the ATP13A2-mediated protection requires binding of PI(3,5P2 to LBS2 and PA to LBS3. Thus, targeting the N-terminal lipid binding sites of ATP13A2 might offer a therapeutic approach to reduce cellular toxicity of various PD insults including mitochondrial stress.

  8. Inorganic–organic hybrids presenting high basic center content: SBA-15 incorporation, toxic metals sorption and energetic behavior

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Fernando J.V.E. [Departamento de Química, Universidade Federal da Paraíba, 58059-900 João Pessoa, PB (Brazil); Melo, Maurício A. [Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, São Paulo (Brazil); Airoldi, Claudio, E-mail: airoldi@iqm.unicamp.br [Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, São Paulo (Brazil)

    2013-03-15

    Highlights: ► Mesoporous SBA-15 silicas were organofunctionalized with new silylant agents. ► Thiocarbamate was used to enhance the silylating agent chains and basic centers. ► The synthesized pendant chains contain nitrogen and sulfur basic centers. ► The new hybrids sorb toxic cations from aqueous solutions with high efficiency. ► The thermodynamic data demonstrated favorable cation/basic center interactions. - Abstract: Mesoporous SBA-15 samples were organofunctionalized with mono, di- and tri-aminosilanes that previously reacted with thiocarbamide to enhance the organic chains and attach nitrogen and sulfur basic centers to the surface of the solids. These new organosilanes were synthesized through a non-solvent approach to reduce both cost and hazardous wastes. The high affinities for both hard and soft Lewis acids due to the combination of nitrogen and sulfur atoms attached to the same pendant chain enabled favorable sorption capacities for Cu{sup 2+}, Cd{sup 2+} and Pb{sup 2+} cations, with maximum capacities of 1.90, 3.48 and 5.30 mmol g{sup −1}, respectively, for the most efficient mesoporous silica. Microcalorimetric investigations allowed the calculation of the thermodynamic data at the solid/liquid interface. All Gibbs energy are negative as expected for spontaneous cation/basic center interactions and the positive entropic values from 49 ± 3 to 108 ± 5 J K{sup −1} mol{sup −1}, also reinforced this favorable interactive process in heterogeneous system. The designed organosilanes covalently bonded to the inorganic siliceous skeleton can be suggested as new materials for toxic metal removal from a wastewater with high efficiency.

  9. Effects of the interleukin-6 (IL-6) polymorphism on toxic metal and trace element levels in placental tissues

    International Nuclear Information System (INIS)

    The placenta is a crucial organ of fetal origin that functions in providing nutrients to the fetus from the mother. During pregnancy, the need for essential micronutrients, such as Fe and Zn, increases due to the requirements of the growing fetus. Maternal Fe deficiency induces an increase in Cu levels and can also affect cytokine levels in the placenta. On the other hand, Cu deficiency, although not as common, can also have destructive effects on the fetus. Interleukin-6 (IL-6) is a pleiotropic cytokine with a wide range of biological activities, including such as immune responses, acute-phase reactions, and inflammation. The placenta produces a significant amount of IL-6 during pregnancy. The effects of the IL-6 -174 G/C single nucleotide polymorphism (SNP) on IL-6 gene transcription and on plasma cytokine levels were assessed in the present study. We investigated the association between the IL-6 -174 G/C polymorphism and trace element/toxic metal levels in placental tissues. For the purposes of this study, 95 healthy volunteers were evaluated. Presence of the IL-6 polymorphism was determined using the standard polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique, and metal levels were analyzed by atomic absorption spectrometry (AAS). Based on our data, there were no significant associations between the IL-6 -174 G/C polymorphism and Pb, Cd, Fe, or Zn levels in the placental tissues (p > 0.05), but a statistically significant association was detected between the polymorphism and Cu levels (p = 0.016). We determined that the mean Cu levels in the placental tissues from individuals with GG, GC and CC genotypes were 5.62 ± 1.98, 6.22 ± 3.22 and 8.00 ± 1.32 ppm, respectively, whereas the overall mean Cu level from the placental tissues was 5.98 ± 2.51 ppm. - Highlights: → We studied between the association of IL-6 polymorphism and metal levels in the placenta tissues. → It was the first report evaluating the association

  10. Do weirs affect the physical and geochemical mobility of toxic metals in mining-impacted floodplain sediments?

    Science.gov (United States)

    Bulcock, Amelia; Coleman, Alexandra; Whitfield, Elizabeth; Andres Lopez-Tarazon, Jose; Byrne, Patrick; Whitfield, Greg

    2015-04-01

    Weirs are common river structures designed to modify river channel hydraulics and hydrology for purposes of navigation, flood defence, irrigation and hydrometry. By design, weirs constrain natural flow processes and affect sediment flux and river channel forms leading to homogenous river habitats and reduced biodiversity. The recent movement towards catchment-wide river restoration, driven by the EU Water Framework Directive, has recognised weirs as a barrier to good ecological status. However, the removal of weirs to achieve more 'natural' river channels and flow processes is inevitably followed by a period of adjustment to the new flow regime and sediment flux. This period of adjustment can have knock-on effects that may increase flood risk, sedimentation and erosion until the river reaches a state of geomorphological equilibrium. Many catchments in the UK contain a legacy of toxic metals in floodplain sediments due to historic metal mining activities. The consequences of weir removal in these catchments may be to introduce 'stored' mine wastes into the river system with severe implications for water quality and biodiversity. The purpose of this study is to investigate the potential impact of a weir on the physical and geochemical mobilisation of mine wastes in the formerly mined River Twymyn catchment, Wales. Our initial investigations have shown floodplain and riverbed sediments to be grossly contaminated (up to 15,500 mg/kg Pb) compared to soil from a pre-mining Holocene terrace (180 mg/kg Pb). Geomorphological investigations also suggest that weir removal will re-establish more dynamic river channel processes resulting in lateral migration of the channel and erosion of contaminated floodplain sediments. These data will be used as a baseline for more detailed investigations of the potential impact of weirs on the physical and geochemical mobilisation of contaminated sediments. We have two specific objectives. (1) Geomorphological assessments will use unmanned

  11. Airborne geoid determination

    DEFF Research Database (Denmark)

    Forsberg, René; Olesen, Arne Vestergaard; Bastos, L.; Gidskehaug, A.; Meyer, U.; Timmen, L.

    2000-01-01

    Airborne geoid mapping techniques may provide the opportunity to improve the geoid over vast areas of the Earth, such as polar areas, tropical jungles and mountainous areas, and provide an accurate "seam-less" geoid model across most coastal regions. Determination of the geoid by airborne methods...... relies on the development of airborne gravimetry, which in turn is dependent on developments in kinematic GPS. Routine accuracy of airborne gravimetry are now at the 2 mGal level, which may translate into 5-10 cm geoid accuracy on regional scales. The error behaviour of airborne gravimetry is well...

  12. The Bioaccumulation and Toxicity of Platinum Group Metals in Developing Chick Embryos

    Science.gov (United States)

    Pavel, Ioana; Monahan, Jennifer; Markopoulos, Marjorie; Gagnon, Zofia; Nejame, Britney; Cawley, Jacob; Reens, David

    2008-10-01

    Recent studies showed that platinum group metals (PGMs) such as Pt, Pd, and Rh from automobile catalytic converters, can accumulate in the soft tissues of a variety of living organisms. However, the effects of PGMs on bone and organs development of animals are not clearly understood. To examine these aspects, developing chick embryos were injected with 0.1, 1.0, 5, or 10 ppm solutions of Pt, Rh, Pd, or with a PGMs mixture. 1) Pathological Changes: were observed for all PGM treatments above 1 ppm. Bone Cells Assesment: Chondrocyte cells in thibiotarsus showed decreased diameter and length. 2) PGMs Accumulation in Tissues: was quantified by GFAAS spectrometry on finely ground tissue powder. 3) Bone Demineralization: was detected by micro-Raman spectroscopy imaging on paraffin embedded bone sections. 4) DNA Damage in Cells: was determined by using a Comet assay and fluorescence spectroscopy. Oxidative Damage in Tissues: was analyzed using a glutathione peroxidase assay. The overall results indicated that PGMs presence in our environment raises concerns about their long-term health effects on all organisms.

  13. Determination of toxic heavy metals in Echinodermata and Chordata species from South Korea.

    Science.gov (United States)

    Choi, Ji Yeon; Habte, Girum; Khan, Naeem; Nho, Eun Yeong; Hong, Joon Ho; Choi, Hoon; Park, Kyung Su; Kim, Kyong Su

    2014-01-01

    This study aimed at analysing concentrations of heavy metals including arsenic, lead, cadmium, aluminium and mercury in commonly consumed seafood species belonging to Echinodermata (Anthocidaris crassispina and Stichopus japonicus) and Chordata (Halocynthia roretzi and Styela plicata). The samples were digested by a microwave system and analysed for As, Cd and Pb by inductively coupled plasma mass spectrometer, for Al by inductively coupled plasma-optical emission spectrometer and Hg by Direct Mercury Analyser. The analytical method was validated by determining sensitivity, linearity, precision, spiking recoveries and analysis of the Standard Reference Material (SRM) NIST 1566-b, an Oyster Tissue. Results showed considerably higher accumulation of Al and As in analysed samples, compared to Pb and Cd, while Hg had the lowest contamination. On comparison, the obtained results with the recommended standards by the Food and Agriculture Organization, European Commission and Ministry of Food and Drug Safety of Korea, it was concluded that the analysed seafoods were safe and thus would not pose a threat to consumers. PMID:24916139

  14. Microorganism mediated biosynthesis of metal chalcogenides; a powerful tool to transform toxic effluents into functional nanomaterials.

    Science.gov (United States)

    Vena, M Paula; Jobbágy, Matías; Bilmes, Sara A

    2016-09-15

    Cadmium contained in soil and water can be taken up by certain crops and aquatic organisms and accumulate in the food-chain, thus removal of Cd from mining or industrial effluents - i.e. Ni-Cd batteries, electroplating, pigments, fertilizers - becomes mandatory for human health. In parallel, there is an increased interest in the production of luminescent Q-dots for applications in bioimaging, sensors and electronic devices, even the present synthesis methods are economic and environmentally costly. An alternative green pathway for producing Metal chalcogenides (MC: CdS, CdSe, CdTe) nanocrystals is based on the metabolic activity of living organisms. Intracellular and extracellular biosynthesis of can be achieved within a biomimetic approach feeding living organisms with Cd precursors providing new routes for combining bioremediation with green routes for producing MC nanoparticles. In this mini-review we present the state-of-the-art of biosynthesis of MC nanoparticles with a critical discussion of parameters involved and protocols. Few existing examples of scaling-up are also discussed. A modular reactor based on microorganisms entrapped in biocompatible mineral matrices - already proven for bioremediation of dissolved dyes - is proposed for combining both Cd-depletion and MC nanoparticle's production. PMID:27157896

  15. Metallo-Graphene Nanocomposite Electrocatalytic Platform for the Determination of Toxic Metal Ions

    Directory of Open Access Journals (Sweden)

    Emmanuel I. Iwuoha

    2011-04-01

    Full Text Available A Nafion-Graphene (Nafion-G nanocomposite solution in combination with an in situ plated mercury film electrode was used as a highly sensitive electrochemical platform for the determination of Zn2+, Cd2+, Pb2+ and Cu2+ in 0.1 M acetate buffer (pH 4.6 by square-wave anodic stripping voltammetry (SWASV. Various operational parameters such as deposition potential, deposition time and electrode rotation speed were optimized. The Nafion-G nanocomposite sensing platform exhibited improved sensitivity for metal ion detection, in addition to well defined, reproducible and sharp stripping signals. The linear calibration curves ranged from 1 µg L−1 to 7 µg L−1 for individual analysis. The detection limits (3σ blank/slope obtained were 0.07 µg L−1 for Pb2+, Zn2+ and Cu2+ and 0.08 µg L−1 for Cd2+ at a deposition time of 120 s. For practical applications recovery studies was done by spiking test samples with known concentrations and comparing the results with inductively coupled plasma mass spectrometry (ICP-MS analyses. This was followed by real sample analysis.

  16. Removal of toxic metals from aqueous effluents by electrodeposition in a spouted bed electrochemical reactor.

    Science.gov (United States)

    Martins, Rosimeire; Britto-Costa, Pedro H; Ruotolo, Luís Augusto M

    2012-06-01

    This work investigates the removal of metal ions from synthetic aqueous effluents using a spouted bed electrochemical reactor whose cathode was composed of 1.0 mm copper particles. Using a Box-Behnken factorial design, the effects of current (I), electrode thickness (L), draught distance (d) and support electrolyte concentration (C(s)) on current efficiency (CE), space-time yield (Y) and energy consumption (EC) were analysed. The results were statistically analysed and the effect of each variable was evaluated using the surface response methodology. The results showed that C(s) is the most important variable to consider in the process optimization. A current of 8.0 A can be applied in order to obtain high Y and CE with an acceptable EC. Electrode thicknesses greater than 1.3 cm are not recommended because the irregular potential distribution leads to a Y drop owing to the low CE observed for this condition. The draught distance does not have statistical significance; therefore, the particle circulation rate is not important in this kind of electrochemical reactor. PMID:22856281

  17. Roadside dust contamination with toxic metals along industrial area in Islamabad, Pakistan

    International Nuclear Information System (INIS)

    An investigation has been carried out to understand the contamination characteristics of roadside dust in the industrial area of Islamabad, Pakistan. The amounts of Si, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Pb, Zn, Ga, As, Se and Cd were determined from 95 roadside dust samples collected along the Islamabad industrial area using Proton Induced X-ray Emission (PIXE). The results indicated that concentrations of all elements, except Cd, in the roadside dust were significant. The results of the enrichment factor show that the elementary composition of the roadside dust could be categorized as soil elements from the crust of the earth and elements from anthropogenic pollution. The high enrichment factors imply that elements such Cr, Cu, Pb, Zn, As, Se, Cd, Ni, Co and S came from anthropogenic activities. The source of metal contamination was identified using multivariate statistical analysis. It has been concluded that Ca, Sc, Ti, V, Mn and Fe mainly originate from crustal sources, Cr, Cu, Ni, Pb, Zn and Ga are associated with point-sources from industrial pollution/traffic; and S, Cl, K, As and Se are mainly related to oil/coal combustion. (authors)

  18. Acute and reproductive toxicity of nano-sized metal oxides (ZnO and TiO₂) to earthworms (Eisenia fetida).

    Science.gov (United States)

    Cañas, Jaclyn E; Qi, Beibei; Li, Shibin; Maul, Jonathan D; Cox, Stephen B; Das, Sriya; Green, Micah J

    2011-12-01

    An increase in nanomaterial applications will likely lead to an increased probability of environmental exposures, raising concerns regarding the safety of these materials. Recent studies have indicated that manufactured nanomaterials, such as metal oxides, have the potential to be harmful to aquatic and terrestrial organisms. The majority of nano-metal oxide research addressing potential toxicological issues has been focused in aquatic environments with very little terrestrial data. This study characterized the acute and reproductive toxicity of zinc oxide (ZnO) and titanium dioxide (TiO(2)) to earthworms (Eisenia fetida) in a terrestrial system. Following a 14 d exposure, nano-sized ZnO on filter paper was acutely toxic to E. fetida, while nano-sized TiO(2) did not exhibit acute toxicity. In contrast, neither nano-sized ZnO nor TiO(2) exhibited acute toxicity to earthworms in sand. Both nano-sized ZnO and TiO(2), following a 4 week exposure, caused reproductive effects in earthworms in artificial soil. Overall, nano-sized ZnO exhibited greater toxicity than nano-sized TiO(2) in Eisenia fetida. PMID:22020256

  19. Toxic heavy metals in the muscle of roe deer (Capreolus capreolus)--food toxicological significance.

    Science.gov (United States)

    Lehel, József; Laczay, Péter; Gyurcsó, Adrienn; Jánoska, Ferenc; Majoros, Szilvia; Lányi, Katalin; Marosán, Miklós

    2016-03-01

    The study was performed on 20 (10 males, 10 females) roe deer (Capreolus capreolus) to investigate the concentration of cadmium, lead, mercury, and arsenic in the muscle tissue. They reside in forest and meadow, about 50 km distance from industrial activities and traffic. Samples were taken from the musculus biceps femoris of each deer without external contamination after shooting during the regular hunting season on a hunting area close to Eger in Hungary. The determination of heavy metal contents was carried out by inductively coupled plasma optical emission spectrometry (ICP-OES). The statistical analysis was performed by statistical package for the social sciences (SPSS) version 11.0. The measured residue concentration of cadmium was below the limit of detection in the roe deer meat indicating no health risk for the consumers. The average lead concentration (0.48 ± 0.21 mg/kg wet weight) exceeded the regulated maximum limit, but its calculated weekly intake was below the provisional tolerable weekly intake (PTWI). The residue level of mercury is not regulated and the average mercury content of roe deer meat (0.87 ± 0.40 mg/kg wet weight) was about half of PTWI, but the consumption of meat with the highest detected concentrations results in higher PTWI than recommended. The measured concentration of arsenic (0.27 ± 0.20 mg/kg wet weight) in the roe deer meat may not pose any health risk for the human consumers according to the PTWI set by the World Health Organization. PMID:26507733

  20. Bioavailability and Chronic Toxicity of Metal Sulfide Minerals to Benthic Marine Invertebrates: Implications for Deep Sea Exploration, Mining and Tailings Disposal.

    Science.gov (United States)

    Simpson, Stuart L; Spadaro, David A

    2016-04-01

    The exploration and proposed mining of sulfide massive deposits in deep-sea environments and increased use deep-sea tailings placement (DSTP) in coastal zones has highlighted the need to better understand the fate and effects of mine-derived materials in marine environments. Metal sulfide ores contain high concentrations of metal(loid)s, of which a large portion exist in highly mineralized or sulfidised forms and are predicted to exhibit low bioavailability. In this study, sediments were spiked with a range of natural sulfide minerals (including chalcopyrite, chalcocite, galena, sphalerite) to assess the bioavailability and toxicity to benthic invertebrates (bivalve survival and amphipod survival and reproduction). The metal sulfide phases were considerably less bioavailable than metal contaminants introduced to sediment in dissolved forms, or in urban estuarine sediments contaminated with mixtures of metal(loid)s. Compared to total concentrations, the dilute-acid extractable metal(loid) (AEM) concentrations, which are intended to represent the more oxidized and labile forms, were more effective for predicting the toxicity of the sulfide mineral contaminated sediments. The study indicates that sediment quality guidelines based on AEM concentrations provide a useful tool for assessing and monitoring the risk posed by sediments impacted by mine-derived materials in marine environments. PMID:26937684

  1. Remediation and reclamation of soils heavily contaminated with toxic metals as a substrate for greening with ornamental plants and grasses.

    Science.gov (United States)

    Jelusic, Masa; Lestan, Domen

    2015-11-01

    Soils highly contaminated with toxic metals are currently treated as waste despite their potential inherent fertility. We applied EDTA washing technology featuring chelant and process water recovery for remediation of soil with 4037, 2527, and 26 mg kg(-1) of Pb, Zn and Cd, respectively in a pilot scale. A high EDTA dose (120 mmol kg(-1) of soil) removed 70%, 15%, and 58% of Pb, Zn, and Cd, respectively, and reduced human oral bioaccessibility of Pb below the limit of quantification and that of Zn and Cd 3.4 and 3.2 times. In a lysimeters experiment, the contaminated and remediated soils were laid into two garden beds (4×1×0.15 m) equipped with lysimeters, and subjected to cultivation of ornamental plants: Impatiens walleriana, Tagetes erecta, Pelargonium×peltatum, and Verbena×hybrida and grasses: Dactylis glomerata, Lolium multiflorum, and Festuca pratensis. Plants grown on remediated soil demonstrated the same or greater biomass yield and reduced the uptake of Pb, Zn and Cd up to 10, 2.5 and 9.5 times, respectively, compared to plants cultivated on the original soil. The results suggest that EDTA remediation produced soil suitable for greening. PMID:25577699

  2. Quantitative analysis of toxic metals lead and cadmium in water jet by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Cheri, M. Sadegh; Tavassoli, S. H.

    2011-03-20

    Laser-induced breakdown spectroscopy (LIBS) has been applied to the analysis of toxic metals Pb and Cd in Pb(NO{sub 3}){sub 2} and Cd(NO{sub 3}){sub 2}.4H{sub 2}O aqueous solutions, respectively. The plasma is generated by focusing a nanosecond Nd:YAG ({lambda}=1064 nm) laser on the surface of liquid in the homemade liquid jet configuration. With an assumption of local thermodynamic equilibrium (LTE), calibration curves of Pb and Cd were obtained at different delay times between 1 to 5 {mu}s. The temporal behavior of limit of detections (LOD) was investigated and it is shown that the minimum LODs for Pb and Cd are 4 and 68 parts in 10{sup 6} (ppm), respectively. In order to demonstrate the correctness of the LTE assumption, plasma parameters including plasma temperature and electron density are evaluated, and it is shown that the LTE condition is satisfied at all delay times.

  3. Quantitative analysis of toxic metals lead and cadmium in water jet by laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Cheri, M Sadegh; Tavassoli, S H

    2011-03-20

    Laser-induced breakdown spectroscopy (LIBS) has been applied to the analysis of toxic metals Pb and Cd in Pb(NO3)2 and Cd(NO3)2.4H2O aqueous solutions, respectively. The plasma is generated by focusing a nanosecond Nd:YAG (λ=1064 nm) laser on the surface of liquid in the homemade liquid jet configuration. With an assumption of local thermodynamic equilibrium (LTE), calibration curves of Pb and Cd were obtained at different delay times between 1 to 5 μs. The temporal behavior of limit of detections (LOD) was investigated and it is shown that the minimum LODs for Pb and Cd are 4 and 68 parts in 10(6) (ppm), respectively. In order to demonstrate the correctness of the LTE assumption, plasma parameters including plasma temperature and electron density are evaluated, and it is shown that the LTE condition is satisfied at all delay times. PMID:21460994

  4. Toxic metal, micro and macronutrient assessment in fish most consumed by Iguape community, Sao Paulo state, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Favaro, Deborah I.T.; Vieira, Andre S.; Bordon, Isabella C.A.C., E-mail: defavaro@ipen.br, E-mail: isabella.bordon@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Farias, Luciana A., E-mail: lufarias2@yahoo.com.br [Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil); Braga, Elisabete S., E-mail: edsbraga@usp.br [Universidade de Sao Paulo (LABNUT/IO/USP), Sao Paulo, SP (Brazil). Instituto Oceanografico

    2013-07-01

    It is well-known that, fish is an important source of protein for populations around the world. As such, fish consumption has increased because it is a healthy and low cholesterol source of protein and other nutrients. The city of Iguape, in the extreme south of the Sao Paulo State coast, is located in a well-preserved Atlantic Forest region. During the last two centuries the city suffered from drastic environmental changes, reinforcing the importance of environmental monitoring in this region. In the present study, 23 samples of the three most consumed fish species by the Iguape city population were analyzed. Fish samples were bought at local markets, conditioned in isothermic boxes in crushed ice (-4 deg C) and then identified before registering the biometric information (total length, total weight and body weight). The following micro and macronutrients As, Br, Ca, Co, Fe, K, Na, Rb, Sc, Se and Zn concentration in muscle from 02 predatory fish species Macrodon ancylodon (King weakfish - Pescada) and Centropomus parallelus (Fat snook - Robalo peba) and one detritivorus species: Anchoviella lepidentostole (Broadband anchovy - Manjuba) were assessed by INAA. Toxic metals Cd, Hg and Pb were also evaluated by AAS. Statistical correlation between element concentrations and fish species were tested. (author)

  5. Contents and toxicity of heavy metals in soils of the zone affected by aerial emissions from the Severonikel Enterprise

    Science.gov (United States)

    Evdokimova, G. A.; Kalabin, G. V.; Mozgova, N. P.

    2011-02-01

    In 2009, the zoning of the terrestrial ecosystems in the area exposed to aerial emissions from the Severonikel Enterprise (Murmansk oblast) was performed on the basis of the parameters characterizing the state of the soils, including the contents of the main heavy metal pollutants and exchangeable calcium and magnesium, the soils' pH, the ratio of the organic to mineral soil components, and the state of the soils' microbiota. Three zones differing in the degree of the soil pollution were delimited. These were the zones of heavy, moderate, and weak pollution, which extended for up to 3, 25, and 50 km from the emission source in the prevailing wind direction. The data on the amount of bacterial and fungal biomass provided evidence of the profound degradation of the soils in the heavily polluted zone. In particular, the biomass of the soil microbiota, including its prokaryotic and eukaryotic components, was two to six times lower in this zone than in the background (control) area. The soils of the heavily polluted zone can be classified as strongly toxic for plants, and most of the soils of the moderately polluted zone also fall into the same category.

  6. Variations in Toxic Metal Levels of Two Fish Species, Pomatomus saltatrix and Dicentrarchus labrax, and Risk Estimation for Children

    Institute of Scientific and Technical Information of China (English)

    Mehmet Yaman; Ibrahim H. Yaman

    2014-01-01

    The concentrations of five toxic metals were monthly determined in two fish species ,obtained from fish markets in Turkey during 2010-2011 .For the determinations ,AAS and ICP-AES were used .The ob-tained lead concentrations for all studied Pomatomus saltatrix (mean 635 μg · kg -1 ) and Dicentrarchus labrax (mean 463 μg · kg -1 ) samples were found to be significantly higher than the maximum allowances concentra-tion (MAC) of 300 μg · kg -1 .Mean chromium (324 μg · kg -1 ) and Cu (940 μg · kg -1 ) concentrations in Pomatomus saltatrix were higher than in Dicentrarchus labrax (268 μg Cr · kg -1 and 600 μg Cu · kg -1 ) while Ni in Pomatomus saltatrix (216μg · kg -1 ) was lower in Dicentrarchus labrax (291μg · kg -1 ) .The estimated non-carcinogenic and carcinogenic health risks by the Target Hazard Quotient and target carcinogenic risk indi-cate that there are no sytemic effects ,and the risk of developing cancer over a human lifetime is between 2~9 in 1 000 000 .

  7. Toxic metal, micro and macronutrient assessment in fish most consumed by Iguape community, Sao Paulo state, Brazil

    International Nuclear Information System (INIS)

    It is well-known that, fish is an important source of protein for populations around the world. As such, fish consumption has increased because it is a healthy and low cholesterol source of protein and other nutrients. The city of Iguape, in the extreme south of the Sao Paulo State coast, is located in a well-preserved Atlantic Forest region. During the last two centuries the city suffered from drastic environmental changes, reinforcing the importance of environmental monitoring in this region. In the present study, 23 samples of the three most consumed fish species by the Iguape city population were analyzed. Fish samples were bought at local markets, conditioned in isothermic boxes in crushed ice (-4 deg C) and then identified before registering the biometric information (total length, total weight and body weight). The following micro and macronutrients As, Br, Ca, Co, Fe, K, Na, Rb, Sc, Se and Zn concentration in muscle from 02 predatory fish species Macrodon ancylodon (King weakfish - Pescada) and Centropomus parallelus (Fat snook - Robalo peba) and one detritivorus species: Anchoviella lepidentostole (Broadband anchovy - Manjuba) were assessed by INAA. Toxic metals Cd, Hg and Pb were also evaluated by AAS. Statistical correlation between element concentrations and fish species were tested. (author)

  8. Immune Alterations in Rats Exposed to Airborne Lunar Dust

    Science.gov (United States)

    Crucian, Brian; Quiriarte, Heather; Nelman, Mayra; Lam, Chiu-wing; James, John T.; Sams, Clarence

    2014-01-01

    The lunar surface is covered by a layer of fine, reactive dust. Very little is known regarding the toxicity of lunar dust on human physiology. This study assessed the toxicity of airborne lunar dust exposure in rats on pulmonary and systemic immune parameters.

  9. Airborne particulate matter, platinum group elements and human health: a review of recent evidence.

    Science.gov (United States)

    Wiseman, Clare L S; Zereini, Fathi

    2009-04-01

    Environmental concentrations of the platinum group elements (PGE) platinum (Pt), palladium (Pd) and rhodium (Rh) have been on the rise, due largely to the use of automobile catalytic converters which employ these metals as exhaust catalysts. It has generally been assumed that the health risks associated with environmental exposures to PGE are minimal. More recent studies on PGE toxicity, environmental bioavailability and concentrations in biologically relevant media indicate however that environmental exposures to these metals may indeed pose a health risk, especially at a chronic, subclinical level. The purpose of this paper is to review the most recent evidence and provide an up-to-date assessment of the risks related to environmental exposures of PGE, particularly in airborne particulate matter (PM). This review concludes that these metals may pose a greater health risk than once thought for several reasons. First, emitted PGE may be easily mobilised and solubilised by various compounds commonly present in the environment, thereby enhancing their bioavailability. Second, PGE may be transformed into more toxic species upon uptake by organisms. The presence of chloride in lung fluids, for instance, may lead to the formation of halogenated PGE complexes that have a greater potential to induce cellular damage. Third, a significant proportion of PGE found in airborne PM is present in the fine fraction that been found to be associated with increases in morbidity and mortality. PGE are also a concern to the extent that they contribute to the suite of metals found in fine PM suspected of eliciting a variety of health effects, especially in vulnerable populations. All these factors highlight the need to monitor environmental levels of PGE and continue research on their bioavailability, behaviour, speciation and associated toxicity to enable us to better assess their potential to elicit health effects in humans. PMID:19181366

  10. [Comparative Sensitivity of the Luminescent Photobacterium phosphoreum, Escherichia coli, and Bacillus subtilis Strains to Toxic Effects of Carbon-Based Nanomaterials and Metal Nanoparticles].

    Science.gov (United States)

    Deryabina, D G; Efremova, L V; Karimov, I F; Manukhov, I V; Gnuchikh, E Yu; Miroshnikov, S A

    2016-01-01

    A comparative analysis of the four commercially available and laboratory luminescent sensor strains to the toxic effect of 10 carbon-based nanomatherials (CBNs) and 10 metal nanoparticles (MNPs) was carried out in this study. The bioluminescence inhibition assays with marine Photobacterium phosphoreum and recombinant Escherichia coli strains were varied in minimal toxic concentrations and EC50 values but led to well correlated biotoxicity evaluation for the most active compounds were ranked as Cu > (MgO, CuO) > (fullerenol, graphene oxide). The novel sensor strain Bacillus subtilis EG 168-1 exhibited the highest sensitivity to CBNs and MNPs that increased significantly number of toxic compounds causing the bacterial bioluminescence inhibition effect. PMID:27476206

  11. Assessment of Individual and Combined Toxicities of Four Non-Essential Metals (As, Cd, Hg and Pb in the Microtox Assay

    Directory of Open Access Journals (Sweden)

    Paul B. Tchounwou

    2006-03-01

    Full Text Available Although most researches with non-essential metals (NEMs have been done with single or individual metals, in reality, organisms are often exposed to multiple contaminants at the same time through the air, food and water. In this study, we tested the toxicity of four NEMs, As, Cd, Pb, and Hg, individually and as a composite mixture using the microtox bioassay. This assay uses the reduction of bioluminescence of the bacterium Vibrio fischeri as a measure of toxicity. The concentrations of each chemical in the mixture were based on multiples of their maximum contaminant levels (MCLs set by the U.S. EPA. The highest concentration of exposure was 20 times the MCL, which translated into 200, 100, 40 and 300 ppb for As, Cd, Hg and Pb, respectively. The ratio for the mixture from these concentrations was 10:5:2:15 for As, Cd, Hg and Pb, respectively. Among the individual metals tested, the ranking of toxicity was Hg>Pb>Cd>As based on the EC50 values of 109, 455, 508 and 768 ppb for Hg, Pb, Cd and As, respectively. The EC50 for the composite mixture was 495% MCL which translated into nominal concentrations of 49, 25, 10 and 74 ppb for As, Cd, Hg, and Pb, respectively. Overall, the EC50 value of each NEM within the mixture was lower than the EC50 of the individual chemical; an evidence of synergism for the mixture. The individual toxic units (TU were 0.06, 0.05, 0.09, and 0.16 for As, Cd Hg, and Pb, respectively and the summed toxic unit (TU was 0.37 (less than 1. This study provides needed scientific data necessary for carrying out complete risk assessment of As, Cd, Hg, and Pb mixtures of some priority compounds.

  12. Application of tracer packet technique to the study of the bio-sorption of heavy and toxic metal radionuclides by algae

    International Nuclear Information System (INIS)

    The bio-sorption of heavy and toxic radionuclides by three genera of algae from different taxonomic groups was studied employing the recently developed 'Tracer Packet' technique. The 'tracer packet of heavy and toxic metals' contained 197Hg, 198,199,200,201Tl, 199,200,201Pb, 204Bi and 204,205Po radionuclides in carrier-free state and was produced by irradiating a gold metal foil with medium energy 7Li and 12C beams successively in a 12 MV Pelletron. Three genera, Spirulina from Cyanophyceae, Oedogonium from Chlorophyceae and Catenella from Rhodophyceae were cultured in laboratory condition and were used in the experiment. The radionuclide accumulation varied according to different genera at different pH levels. At basic pH Spirulina showed a maximum radionuclide accumulation in comparison to other genera. (author)

  13. Microwaves in Airborne Surveillance

    OpenAIRE

    Christopher, S.

    2013-01-01

    The use of microwave spectrum is widespread due to its convenience. Therefore, enormous amount of information is available in the free space channel. Obviously, mining this channel for surveillance is quite common. Airborne surveillance offers significant advantages in military operations. This paper talks of the usage of microwaves in airborne surveillance systems, in general, and in the Indian airborne early warning and control (AEW&C) System, in particular. It brings out the multiple s...

  14. Application of principal component analysis in the assessment of essential and toxic metals in vegetable and soil from polluted and referent areas

    OpenAIRE

    Balabanova, Biljana; Stafilov, Trajče; Baceva, Katerina

    2015-01-01

    The aim of the paper is to assess the 23 elements distribution in agricultural soil and vegetables [garlic (Allium sativum), onion (Allium cepa) and parsley (Petroselinum crispum)] widely used as food in areas contaminated with toxic metals due to long-lasting copper mining activities in the Republic of Macedonia. Principal components analysis (PCA) models were computed with different variables: elements contents in vegetables and soil samples collected from contaminated and uncontaminated...

  15. In Vitro Analyses of the Toxicity, Immunological, and Gene Expression Effects of Cobalt-Chromium Alloy Wear Debris and Co Ions Derived from Metal-on-Metal Hip Implants

    Directory of Open Access Journals (Sweden)

    Olga M. Posada

    2015-07-01

    Full Text Available Joint replacement has proven to be an extremely successful and cost-effective means of relieving arthritic pain and improving quality of life for recipients. Wear debris-induced osteolysis is, however, a major limitation and causes orthopaedic implant aseptic loosening, and various cell types including macrophages, monocytes, osteoblasts, and osteoclasts, are involved. During the last few years, there has been increasing concern about metal-on-metal (MoM hip replacements regarding adverse reactions to metal debris associated with the MoM articulation. Even though MoM-bearing technology was initially aimed to extend the durability of hip replacements and to reduce the requirement for revision, they have been reported to release at least three times more cobalt and chromium ions than metal-on-polyethylene (MoP hip replacements. As a result, the toxicity of metal particles and ions produced by bearing surfaces, both locally in the periprosthetic space and systemically, became a concern. Several investigations have been carried out to understand the mechanisms responsible for the adverse response to metal wear debris. This   review aims at summarising in vitro analyses of the toxicity, immunological, and gene expression effects of cobalt ions and wear debris derived from MoM hip implants.

  16. Trace elements and toxic metals in intensively produced tomatoes (lycopersicon esculentum Metales traza y metales tóxicos en tomates producidos intensivamente (lycopersicon esculentum

    Directory of Open Access Journals (Sweden)

    G. Luis

    2012-10-01

    Full Text Available Introduction: Tomato is considered a healthy food due to its high content in lycopene and other health-promoting natural compounds. Tomatoes have, undoubtedly, assumed the status of a food with functional properties, considering the epidemiological evidence of reducing the risk of certain types of cancers. Objective: Samples of tomatoes from Morocco were analyzed for the mineral composition. Methods: 94 tomato samples from Morocco were analyzed. Flame Atomic Absorption Spectrophotometry (FAAS was used to determine essential elements (Copper (Cu, iron (Fe, manganese (Mn and zinc (Zn and Atomic Absorption Spectrophotometry with Graphite Furnace (GAAS was used to analyzed cadmium (Cd and lead (Pb. Results: The mean concentrations were 0.17 mg/kg, 0.73 mg/kg, 0.20 mg/kg, 0.44 mg/kg, 7.58 μg/kg and 15.8 μg/kg for Cu, Fe, Mn, Zn, Cd and Pb, respectively. The highest contribution to the intakes was observed for Cu (0.67% for adults while that Zn showed the lowest contribution (0.14% for adult males and 0.20% for adult females. Conclusions: Tomatoes are a good source of essential elements for the diet, mainly iron and zinc. Tomatoes consumption does not significantly affect the intake of heavy metals.Introducción: El tomate es considerado un alimento saludable debido a su alto contenido en licopeno y otros componentes naturales promotores de salud. Indudablemente, los tomates han asumido el estatus de un alimento con propiedades funcionales, considerando desde un punto de vista epidemiológico reducir ciertos tipos de cánceres Objetivo: Analizar la composición mineral de muestras de tomates de Marruecos. Métodos: 94 muestras de tomates de Marruecos fueron analizadas. Espectrofotometría de Absorción Atómica por llama (FAAS se usó para determinar elementos esenciales (Cobre (Cu, hierro (Fe, manganeso (Mn y zinc (Zn y Espectrofotometría de Absorción Atómica con cámara de grafito (GAAS se usó para analizar cadmio (Cd y plomo (Pb. Resultados

  17. Assessment of occupational exposure to toxic metals in some paint and secondary iron and steel industries in Lagos, Nigeria using TXRF technique

    International Nuclear Information System (INIS)

    Full text: Lagos has remained one of the fastest growing cities especially in industrial infrastructure development. This has led to increased environmental problems. Yet there has been very little effort to monitor occupational exposure at various workplaces. Few selected paint industries and few secondary iron and steel industries in Lagos, Southwest Nigeria, were targeted for monitoring the heavy metal concentrations in their working environment. Ambient air at strategic locations within selected industries was sampled for twelve hour periods during the day time and the night time. Sampling was done using a stacked 'Gent' PM10 sampler and a twin-flow portable sampler, the latter for total suspended particulate matter. The filter holders were held at a height of 1.5 m above the ground. The filters were digested using ultra-pure acids and then analysed with a tube-excited Mo target x-ray source operating at 40 kV. Concentrations of toxic metal pollutants were measured using the total refection x-ray fluorescence technique. Quantification of concentrations of toxic metals was done using QXAS analysis package from IAEA. Ga was used as internal standard in the analysis. The elements of interest detected were Ca, Ti, V, Cr, Mn, Fe, Co, Zn and Pb. The ratios of the fine size fractions (dp p 3 to 36.2 μg/m3 for the inhalable fraction. Toxicity potentials for the various elements were determined. (author)

  18. Water treatment residual (WTR)-coated wood mulch for alleviation of toxic metals and phosphorus from polluted urban stormwater runoff.

    Science.gov (United States)

    Soleimanifar, Hanieh; Deng, Yang; Wu, Laying; Sarkar, Dibyendu

    2016-07-01

    Aluminum-based water treatment residual (WTR)-coated wood mulches were synthesized and tested for removal of heavy metals and phosphorus (P) in synthetic urban stormwater. WTRs are an industrial waste produced from coagulation in water treatment facilities, primarily composed of amorphous aluminum or iron hydroxides. Batch tests showed that the composite filter media could effectively adsorb 97% lead (Pb), 76% zinc (Zn), 81% copper (Cu) and 97% P from the synthetic stormwater (Pb = 100 μg/L, Zn = 800 μg/L, Cu = 100 μg/L, P = 2.30 mg/L, and pH = 7.0) within 120 min, due to the presence of aluminum hydroxides as an active adsorbent. The adsorption was a 2(nd)-order reaction with respect toward each pollutant. Column tests demonstrated that the WTR-coated mulches considerably alleviated the select pollutants under a continuous-flow condition over the entire filtration period. The effluent Pb, Zn, Cu, and P varied at 0.5-8.9%, 33.4-46.7%, 45.8-55.8%, and 6.4-51.9% of their respective initial concentrations with the increasing bed volume from 0 to 50. Synthetic precipitation leaching procedure (SPLP) and toxicity characteristic leaching procedure (TCLP) tests indicated that leached contaminants were all below the U.S. criteria, suggesting that the release of undesired chemicals under rainfall or landfilling conditions is not a concern during application. This study demonstrates that the WTR-coated mulches are a new, low-cost, and effective filter media for urban stormwater treatment. Equally important, this study