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Sample records for twa lead concentration

  1. Additional TWA Members? Spectroscopic verification of kinematically selected TWA candidates

    CERN Document Server

    Song, I; Zuckerman, B; Song, Inseok

    2002-01-01

    We present spectroscopic measurements of the 23 new candidate members of the TW Hydrae Association from Makarov & Fabricius (2000). Based on Halpha and Li 6708 A strengths together with location on a color-magnitude diagram for Hipparcos TWA candidates, we found only three possible new members (TYC 7760-0835-1, TYC 8238-1462-1, and TYC 8234-2856-1) in addition to the already known member, TWA 19. This eliminated most of the candidates more distant than 100 pc. Three Tycho stars, almost certainly members of the Lower Centaurus Crux association, are the most distant members of the TWA. A claim of isotropic expansion of TWA has to be re-evaluated based on our new results. Generally, one cannot identify new members of a diffuse nearby stellar group based solely on kinematic data. To eliminate interlopers with similar kinematics, spectroscopic verification is essential.

  2. Theoretical comments on reproducibility and normalization of TWA measures.

    Science.gov (United States)

    Sassi, Roberto; Mainardi, Luca T

    2013-01-01

    Using a simple stochastic model of ventricular repolarization and the equivalent surface source (ESS) model, an electrophysiological formulation relating surface ECG to variations at the myocytes' level, we recently pointed out a few theoretical results regarding T-wave alternans (TWA). In this paper, stimulated by the comments of John E. Madias on our paper (J Electrocardiol, 2012), we further explored the consequences implied by the theoretical model. First, we verified the reproducibility of TWA measures, in clinically stable patients repeatedly tested. The sensitivity to displacement was evaluated simulating lead mislocations of up to 20mm. The numerical simulations were performed on data obtained solving the inverse electrocardiographically problem from three subjects (ECGSIM). The results showed that TWA sensitivity varies across leads, being maximal in V1 and decreases towards V6. Globally, the maximal percent error found was 6.1%. Thus, TWA measures do not seem to add more stringent requirements on lead placement's precision, than the usual diagnostic practice. Finally, we further discussed the implications of normalizing TWA measures. While clinical studies are necessary to sort out the issue, the theoretical model suggests that normalization might be appropriate only is certain cases.

  3. Combined processing of lead concentrates

    Science.gov (United States)

    Kubasov, V. L.; Paretskii, V. M.; Sidorin, G. N.; Travkin, V. F.

    2013-06-01

    A combined scheme of processing of lead concentrates with the production of pure metallic lead and the important components containing in these concentrates is considered. This scheme includes sulfating roasting of the lead concentrates and two-stage leaching of the formed cinder with the formation of a sulfate solution and lead sulfate. When transformed into a carbonate form, lead sulfate is used for the production of pure metallic lead. Silver, indium, copper, cadmium, nickel, cobalt, and other important components are separately extracted from a solution. At the last stage, zinc is extracted by either extraction followed by electrolytic extraction of a metal or the return of the forming solution of sulfuric acid to cinder leaching.

  4. Individual variability in human tibia lead concentration.

    OpenAIRE

    Todd, A. C.; Parsons, P J; Tang, S.; Moshier, E L

    2001-01-01

    Our aims in this study were to determine proximal-distal variability in adult human tibia lead concentration via electrothermal atomization atomic absorption spectrometry (ETAAS) and to determine whether there were any differences between core and surface tibia lead concentrations. We analyzed duplicate core and surface tibia samples for lead at multiple proximal-distal sections on 10 adult human cadaver legs. Dried bone samples were digested in nitric acid using microwave-assisted heating, a...

  5. Pattern of crescendo TWA may disclose the underlying cardiac pathology.

    Science.gov (United States)

    Nieminen, Tuomo; Verrier, Richard L; Nikus, Kjell; Viik, Jari; Lehtinen, Rami; Lehtimäki, Terho; Kaiser, Willi; Kähönen, Mika

    2010-01-01

    We present an exercise test case in which crescendo TWA preceded ventricular tachycardia (VT). The patient was examined due to suspicion of ischemic heart disease. The ST-segment became elevated simultaneously with a distinct alternation in the ST-segment and the first half of the T-wave, and the patient developed polymorphic VT. Coronary angiography disclosed marked stenoses. Earlier reports of TWA in patients with congenital long QT syndrome show a pattern in which the T wave frequently alternates above and below the isoelectric line without concomitant ST-segment changes. In Brugada syndrome patients, the signature ST-T wave pattern is the locus of alternation. Future investigation should elucidate whether specific TWA morphologies may expose underlying heart disease.

  6. Orbits and masses in the young triple system TWA 5

    CERN Document Server

    Köhler, R; Petr-Gotzens, M G; Correia, S

    2013-01-01

    We aim to improve the orbital elements and determine the individual masses of the components in the triple system TWA 5. Five new relative astrometric positions in the H band were recorded with the adaptive optics system at the Very Large Telescope (VLT). We combine them with data from the literature and a measurement in the Ks band. We derive an improved fit for the orbit of TWA 5Aa-b around each other. Furthermore, we use the third component, TWA 5B, as an astrometric reference to determine the motion of Aa and Ab around their center of mass and compute their mass ratio. We find an orbital period of 6.03+/-0.01 years and a semi-major axis of 63.7+/-0.2 mas (3.2+/-0.1 AU). With the trigonometric distance of 50.1+/-1.8 pc, this yields a system mass of 0.9+/-0.1 Msun, where the error is dominated by the error of the distance. The dynamical mass agrees with the system mass predicted by a number of theoretical models if we assume that TWA5 is at the young end of the age range of the TW Hydrae association. We fin...

  7. Comparison of Spot and Time Weighted Averaging (TWA Sampling with SPME-GC/MS Methods for Trihalomethane (THM Analysis

    Directory of Open Access Journals (Sweden)

    Don-Roger Parkinson

    2016-02-01

    Full Text Available Water samples were collected and analyzed for conductivity, pH, temperature and trihalomethanes (THMs during the fall of 2014 at two monitored municipal drinking water source ponds. Both spot (or grab and time weighted average (TWA sampling methods were assessed over the same two day sampling time period. For spot sampling, replicate samples were taken at each site and analyzed within 12 h of sampling by both Headspace (HS- and direct (DI- solid phase microextraction (SPME sampling/extraction methods followed by Gas Chromatography/Mass Spectrometry (GC/MS. For TWA, a two day passive on-site TWA sampling was carried out at the same sampling points in the ponds. All SPME sampling methods undertaken used a 65-µm PDMS/DVB SPME fiber, which was found optimal for THM sampling. Sampling conditions were optimized in the laboratory using calibration standards of chloroform, bromoform, bromodichloromethane, dibromochloromethane, 1,2-dibromoethane and 1,2-dichloroethane, prepared in aqueous solutions from analytical grade samples. Calibration curves for all methods with R2 values ranging from 0.985–0.998 (N = 5 over the quantitation linear range of 3–800 ppb were achieved. The different sampling methods were compared for quantification of the water samples, and results showed that DI- and TWA- sampling methods gave better data and analytical metrics. Addition of 10% wt./vol. of (NH42SO4 salt to the sampling vial was found to aid extraction of THMs by increasing GC peaks areas by about 10%, which resulted in lower detection limits for all techniques studied. However, for on-site TWA analysis of THMs in natural waters, the calibration standard(s ionic strength conditions, must be carefully matched to natural water conditions to properly quantitate THM concentrations. The data obtained from the TWA method may better reflect actual natural water conditions.

  8. On the physical properties of TWA-2M1207

    Directory of Open Access Journals (Sweden)

    A. Bayo

    2007-01-01

    Full Text Available We have studied some physical properties of 2M1207 (member of TWA. Previously es- timated age for this moving group is 10 Myr. The chronology has been carried out by analysing different properties of this object (Teff, gravity, accretion/activity and lithium in the optical and IR and comparing them with well-known star-forming regions and open clusters, as well as theoretical models.

  9. An evaluation of lead concentrations in imported hot sauces.

    Science.gov (United States)

    Berger Ritchie, Jennifer A; Gerstenberger, Shawn L

    2013-01-01

    In the last decade, the U.S. Food and Drug Administration (FDA) has issued several warnings and recalls for food products that exceed FDA standards for lead. Products containing chili peppers and salt were often suspected as sources of lead contamination, and included items such as candy that are routinely investigated. However, products such as hot sauces that contain similar ingredients have not been the focus of evaluations. This study quantified lead concentrations in imported hot sauces, evaluated product compliance to existing United States standards, and calculated potential dietary lead exposure for children using the Integrated Exposure Uptake Biokinetic Model. Finally, recommendations for reducing the risk of lead exposure from hot sauces are provided. Twenty-five (25) bottles of imported hot sauces manufactured in Mexico and South America were purchased in Clark County, Nevada. All hot sauces were analyzed for lead concentrations, pH, and leaded packaging. Hot sauces were analyzed by inductively coupled plasma mass spectrometry and packaging was analyzed using x-ray fluorescence technology. Four brands of hot sauces (16%) exceeded 0.1 ppm lead, the current FDA action level for lead in candy. Hot sauces with lead concentrations >0.1 ppm lead contained salt and were manufactured in Mexico. Subsequent analysis of additional lots of hot sauces exceeding 0.1 ppm lead revealed inconsistent lead concentrations between and within manufacturer lots. The lead concentrations of the plastic hot sauce lids ranged from below the limit of detection to 2,028 ppm lead. There was no association between lead concentrations in hot sauces and pepper type. These results indicate the need for more rigorous screening protocols for products imported from Mexico, the establishment of an applicable standard for hot sauce, and resources to allow for the enforcement of existing food safety policies. The data reported herein represent the first known investigation of lead

  10. Relationship between soil lead and airborne lead concentrations at Springfield, Missouri, USA

    Energy Technology Data Exchange (ETDEWEB)

    Sheets, R.W.; Kyger, J.R.; Biagioni, R.N.; Probst, S. [Department of Chemistry, Southwest Missouri State University, 65804 Springfield, MO (United States); Boyer, R.; Barke, K. [Greene County Health Department, 65802 Springfield, MO (United States)

    2001-04-23

    This study tests whether lead deposited to soil from automobiles during past years in a medium-sized US city (population 150000) may present a current health risk. It examines the relationship between current soil lead concentrations at nine locations within the city of Springfield, Missouri, and airborne lead levels measured at the same locations during years (1975-1981) when lead emissions from automobiles were much greater than at present. A strong, significant correlation is found between soil and airborne lead levels at eight of the sites (r=0.91, P<0.005 for soil lead vs. 1979 airborne lead), in low-traffic areas as well as in areas adjacent to heavy traffic flow. Residual lead concentrations in these soils are relatively low, even for the high-traffic sites, as expected for a medium sized city.

  11. Lead pellet ingestion and liver-lead concentrations in upland game birds from southern Ontario, Canada.

    Science.gov (United States)

    Kreager, N; Wainman, B C; Jayasinghe, R K; Tsuji, L J S

    2008-02-01

    One-hundred twenty-three gizzards from upland game birds (chukar, Alectoris chukar; and common pheasant, Phasianus colchicus) harvested by hunters in southern Ontario, Canada, were examined for lead pellet ingestion by manual examination of gizzard contents and by radiography. Lead pellets were found to be ingested by chukars (6/76; 8%) and the common pheasant (16/47; 34%). Further, 13% (17/129) of the bird (wild turkey, Meleagris gallopavo; Hungarian partridge, Perdix perdix; chukar; and common pheasant) livers analyzed had elevated lead concentrations (> or =6 microg/g wet weight [ww]). Liver-lead concentrations above Health Canada's guideline for human consumption of fish protein (shotshell for hunting.

  12. Impacts of converting from leaded to unleaded gasoline on ambient lead concentrations in Jakarta metropolitan area

    Institute of Scientific and Technical Information of China (English)

    Akira KONDO; Esrom HAMONANGAN; Satoshi SODA; Akikazu KAGA; Yoshio INOUE; Masaharu EGUCHI; Yuta YASAKA

    2007-01-01

    Total suspended particulate mater (TSP) concentrations were monitored for one year from July 2000 and for one year from April 2003 in Jakarta City. Thirteen elemental TSP components, aluminum (Al), sodium (Na), iron (Fe), lead (Pb), potassium (K), zinc (Zn), titanium (Ti), manganese (Mn), bromine (Br), copper (Cu), chromium (Cr), nickel (Ni), and vanadium (Ⅴ) were analyzed by a sequential X-ray fluorescence spectrometer. Al, Na, Fe, K, and Pb were major components at most of the sampling locations in 2000. However, only Pb in 2003 dramatically decreased to one tenth. The phase-out of leaded gasoline began on July 1, 2001 in Jakarta City and lead content in gasoline decreased to one tenth, too. The decrease in Pb concentration was a result of the phase-out of leaded gasoline, as lead emissions mainly are exhaust gas from vehicles.

  13. Impacts of converting from leaded to unleaded gasoline on ambient lead concentrations in Jakarta metropolitan area.

    Science.gov (United States)

    Kondo, Akira; Hamonangan, Esrom; Soda, Satoshi; Kaga, Akikazu; Inoue, Yoshio; Eguchi, Masaharu; Yasaka, Yuta

    2007-01-01

    Total suspended particulate mater (TSP) concentrations were monitored for one year from July 2000 and for one year from April 2003 in Jakarta City. Thirteen elemental TSP components, aluminum (Al), sodium (Na), iron (Fe), lead (Pb), potassium (K), zinc (Zn), titanium (Ti), manganese (Mn), bromine (Br), copper (Cu), chromium (Cr), nickel (Ni), and vanadium (V) were analyzed by a sequential X-ray fluorescence spectrometer. Al, Na, Fe, K, and Pb were major components at most of the sampling locations in 2000. However, only Pb in 2003 dramatically decreased to one tenth. The phase-out of leaded gasoline began on July 1, 2001 in Jakarta City and lead content in gasoline decreased to one tenth, too. The decrease in Pb concentration was a result of the phase-out of leaded gasoline, as lead emissions mainly are exhaust gas from vehicles.

  14. Breathing zone particle size and lead concentration from sanding operations to remove lead based paints.

    Science.gov (United States)

    Alexander, W K; Carpenter, R L; Kimmel, E C

    1999-02-01

    The relationship between lead concentration in the dry film of lead based paints applied to steel bulkheads aboard ship, the lead concentration found in the air when the paint is removed by mechanical means, and blood lead concentrations of workers involved in lead based paint removal has not been well characterized. Intuitively a direct relationship must exist but confounding factors confuse the issue. Simultaneous sampling procedures from the same paint removal operation may differ by several orders of magnitude. The process from dried film to aerosol (airborne dust) exposure, and on to dose can be separated into two major phases; (1) generation of the dust and its transport through the air to the worker and (2) uptake and dose related factors within the body. Both phases involve complex interactions and there are a number of factors within each phase that significantly affect the potential lead dose for the worker. This study attempts to clarify the mechanisms involved in the generation and transportation of the dust to the worker by evaluating the relationship of a number of key factors on particle size and lead distribution within the aerosol dust generated when lead based paint is removed by sanding. The study examined the relationship between particle size in the dust and grit size of the abrasive. It also examined the distribution of lead within selected particle sizes. The Mass Median Aerodynamic Diameter (MMAD) was used as an indicator of change in the particle size distribution. Particle size distributions were evaluated using a TSI Aerodynamic Particle Sizer, a five stage cyclone and scanning electron microscopy. Lead distribution was determined using the five stage cyclone, and personal or area samples analyzed using inductively coupled plasma (ICP). Mass concentrations were evaluated using a MIE Mass Concentration Analyzer and gravimetric analysis of filter samples collected in the breathing zone. Student's t-tests were used to evaluate changes in

  15. Australian atmospheric lead deposition reconstructed using lead concentrations and isotopic compositions of archival lichen and fungi.

    Science.gov (United States)

    Wu, Liqin; Taylor, Mark Patrick; Handley, Heather K; Wu, Michael

    2016-01-01

    Lead concentrations and their isotopic compositions were measured in lichen genera Cladonia and Usnea and fungi genus Trametes from the Greater Sydney region (New South Wales, Australia) that had been collected and archived over the past 120 years. The median lead contents were elevated in lichens and fungi prior to the introduction of leaded petrol (Cladonia 12.5 mg/kg; Usnea 15.6 mg/kg; Trametes 1.85 mg/kg) corresponding to early industrial development. During the use of leaded petrol for automobiles in Australia from 1932 to 2002, total median lead concentrations rose: Cladonia 18.8 mg/kg; Usnea 21.5 mg/kg; Trametes 4.3 mg/kg. Following the cessation of leaded petrol use, median total lead concentrations decreased sharply in the 2000s: Cladonia 4.8 mg/kg; Usnea 1.7 mg/kg. The lichen and fungi isotopic compositions reveal a significant decrease in (206)Pb/(207)Pb values from the end of 19th century to the 1970s. The following decades were characterised by lower allowable levels of lead additive in fuel and the introduction of unleaded petrol in 1985. The environmental response to these regulatory changes was that lichen and fungi (206)Pb/(207)Pb values increased, particularly from 1995 onwards. Although the lead isotope ratios of lichens continued to increase in the 2000s they do not return to pre-leaded petrol values. This demonstrates that historic leaded petrol emissions, inter alia other sources, remain a persistent source of anthropogenic contamination in the Greater Sydney region.

  16. A systematic review on food lead concentration and dietary lead exposure in China

    Institute of Scientific and Technical Information of China (English)

    Jin Yingliang; Liu Pei; Wu Yongning; Min Jie; Wang Cannan; Sun Jinfang; Zhang Yafei

    2014-01-01

    Background By synthesizing results from primary studies,systematic review can provide empirical information of concerned problems.This study aimed to review the available surveillance data from studies reporting the contamination surveillance of food lead in China.Methods Relevant studies were identified by systematically searching Chinese Biological Medicine Database and China National Knowledge Infrastructure using the key term of "lead" for surveillance data published in Chinese between 2006 and 2012.To avoid potential selection bias,all articles were evaluated by two independent reviewers,and the disagreements were resolved by discussion or the third author was asked to arbitrate.Results Among 269 identified publications on surveillance data of lead in food,43 articles met the defined inclusion criteria.The food samples were divided into 11 groups (cereal grains and pulses,fish,eggs,vegetables,meat,edible fungi,milk and dairy products,fruits,offal,tea and preserved egg).Surveillance data of publications were reviewed to calculate the weighted mean and rate exceeding maximum levels.Our results indicated that the highest lead concentration was 1.937 mg/kg in tea.The total pementage of samples exceeding the maximum levels was 5.57%.Dietary exposure to lead was assessed by combining the weighted mean concentration of surveillance data with national consumption data in 2002.In this review,dietary intake of lead was 1.232 μg/kg b.w./day.Conclusion Further control measures should be taken to reduce exposure to lead,from both dietary and non-dietary sources.

  17. Rumen fermentation and acetogen population changes in response to an exogenous acetogen TWA4 strain and Saccharomyces cerevisiae fermentation product.

    Science.gov (United States)

    Yang, Chun-lei; Guan, Le-luo; Liu, Jian-xin; Wang, Jia-kun

    2015-08-01

    The presence of yeast cells could stimulate hydrogen utilization of acetogens and enhance acetogenesis. To understand the roles of acetogens in rumen fermentation, an in vitro rumen fermentation experiment was conducted with addition of acetogen strain (TWA4) and/or Saccharomyces cerevisiae fermentation product (XP). A 2×2 factorial design with two levels of TWA4 (0 or 2×10(7) cells/ml) and XP (0 or 2 g/L) was performed. Volatile fatty acids (VFAs) were increased (P<0.05) in XP and TWA4XP, while methane was increased only in TWA4XP (P<0.05). The increase rate of microorganisms with formyltetrahydrofolate synthetase, especially acetogens, was higher than that of methanogens under all treatments. Lachnospiraceae was predominant in all acetogen communities, but without close acetyl-CoA synthase (ACS) amino acid sequences from cultured isolates. Low-Acetitomaculum ruminis-like ACS was predominant in all acetogen communities, while four unique phylotypes in XP treatment were all amino acid identified low-Eubacterium limosum-like acetogens. It differs to XP treatment that more low-A. ruminis-like and less low-E. limosum-like sequences were identified in TWA4 and TWA4XP treatments. Enhancing acetogenesis by supplementation with an acetogen strain and/or yeast cells may be an approach to mitigate methane, by targeting proper acetogens such as uncultured low-E. limosum-like acetogens.

  18. Using Lead Concentrations and Stable Lead Isotope Ratios to Identify Contamination Events in Alluvial Soils

    Directory of Open Access Journals (Sweden)

    Diane Saint-Laurent

    2010-01-01

    Full Text Available Soils contaminated with hydrocarbons (C10–C50, polycyclic aromatic hydrocarbons (PAHs, and other contaminants (e.g., As, Cd, Cu, Pb were recently discovered on the banks of the Saint-François and Massawippi rivers. Alluvial soils are contaminated over a distance of 100 kilometers, and the level of the contaminated-hydrocarbon layer in the soil profiles is among the highest at the Windsor and Richmond sites. Concentrations of lead and stable lead isotope ratios (204Pb/206Pb, 207Pb/206Pb, 208Pb/206Pb are also used to identify contamination events. The maximum and minimum values detected in soil profiles for arsenic, cadmium, and lead vary from 3.01 to 37.88 mg kg-1 (As, 0.11 to 0.81 mg kg-1 (Cd 12.32 to 149.13 mg kg-1 (Pb, respectively, while the 207Pb/206Pb isotopic ratio values are between 0.8545 and 0.8724 for all the profiles. The highest values of trace elements (As, Pb and Zn were detected in the hydrocarbon layer (C10–C50, most often located at the bottom of the profiles (160, 200, and 220 cm in depth. The various peaks recorded in the soils and the position of the profiles suggest that various contaminants were transported by the river on several occasions and infiltrated the soil matrix or deposited on floodplains during successive floods. Atmospheric particles which entered the river or deposited on riverbanks must also be considered as another source of pollution recorded in soils.

  19. The Feasibility of Using Lead in Hair Concentration in Monitoring Environmental Exposure in Children

    NARCIS (Netherlands)

    Wibowo, A.A.E.; Brunekreef, B.; Lebret, E.; Pieters, H.

    1980-01-01

    The feasibility of lead in hair as an indicator of lead exposure has been compared to that of lead in blood and zinc protoporphyrin in blood levels in 1-3 year-old children living within 1 km of a lead smelter. Lead exposure was measured as lead in house dust, outdoor and indoor lead in air concentr

  20. Vitamin D receptor Fok1 polymorphism and blood lead concentration in children.

    OpenAIRE

    Haynes, Erin N.; Kalkwarf, Heidi J; Hornung, Richard; Wenstrup, Richard; Dietrich, Kim; Lanphear, Bruce P

    2003-01-01

    Variation in blood lead concentration is caused by a complex interaction of environmental, social, nutritional, and genetic factors. We evaluated the association between blood lead concentration and a vitamin D receptor (VDR) gene polymorphism. Environmental samples and blood were analyzed for lead, nutritional and behavioral factors were assessed, and VDR -Fok1 genotype was determined in 245 children. We found a significant interaction between floor dust lead and genotype on blood lead conce...

  1. The Construction, Enactment, and Maintenance of Power-as-Domination through an Acquisition: The Case of TWA and Ozark Airlines.

    Science.gov (United States)

    Pierce, Tamyra; Dougherty, Debbie S.

    2002-01-01

    Explores how domination was created, enacted, and maintained in the acquisition of Ozark Airlines by TWA. Uses the concepts of resources, hegemony, and resistance from the functionalist, Marxist, and postmodern traditions, respectively, to understand power-as-domination as a complex communication process. Reveals how communication practices were…

  2. Asian industrial lead inputs to the North Pacific evidenced by lead concentrations and isotopic compositions in surface waters and aerosols.

    Science.gov (United States)

    Gallon, Céline; Ranville, Mara A; Conaway, Christopher H; Landing, William M; Buck, Clifton S; Morton, Peter L; Flegal, A Russell

    2011-12-01

    Recent trends of atmospheric lead deposition to the North Pacific were investigated with analyses of lead in aerosols and surface waters collected on the fourth Intergovernmental Oceanographic Commission Contaminant Baseline Survey from May to June, 2002. Lead concentrations of the aerosols varied by 2 orders of magnitude (0.1-26.4 pmol/m(3)) due in part to variations in dust deposition during the cruise. The ranges in lead aerosol enrichment factors relative to iron (1-119) and aluminum (3-168) were similar, evidencing the transport of Asian industrial lead aerosols across the North Pacific. The oceanic deposition of some of those aerosols was substantiated by the gradient of lead concentrations of North Pacific waters, which varied 3-fold (32.7-103.5 pmol/kg), were highest along with the Asian margin of the basin, and decreased eastward. The hypothesized predominance of Asian industrial lead inputs to the North Pacific was further corroborated by the lead isotopic composition of ocean surface waters ((206)Pb/(207)Pb = 1.157-1.169; (208)Pb/(206)Pb = 2.093-2.118), which fell within the range of isotopic ratios reported in Asian aerosols that are primarily attributed to Chinese industrial lead emissions.

  3. The gold contained in imported lead ore concentrate is exempted from import value-added tax

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>According to the No. 14 proclamation issued by Customs Service, as from April 1st 2007, the importation of galena and the lead ore concentrate will enjoy the favorable policy intended for associated gold deposits, i.e. the value-added tax for gold component in the imported galena and lead ore concentrate is exempted,

  4. A geospatial analysis of soil lead concentrations around regional Oklahoma airports.

    Science.gov (United States)

    McCumber, Alexander; Strevett, K A

    2017-01-01

    Lead has been banned from automobile gasoline since 1995; however, lead is still used as an additive to aviation gasoline (avgas). Airports are now one of the greatest sources of lead air emission in the US. The objectives of this study were (1) to evaluate soil lead levels radially from three regional airports; (2) collect historical meteorological data; (3) examine the soil organic matter content and (4) develop correlation coefficients to evaluate correlations among variables. Soil samples were collected from 3 different airports in Oklahoma and the soil lead concentration was measured using x-ray fluorescence (XRF). The measured soil lead concentrations were plotted with the corresponding GPS location in ArcGIS and Inverse Distance Weight spatial analysis was used to create modeled isopleths of soil lead concentrations. One of the three airports was found to have soil lead concentrations that correlate with soil organic matter with one other showing correlation between soil lead concentration and distance from the airport. The spatial modeled isopleths showed elevated soil lead concentrations in the direction of prevailing winds with "hot spots" near the avgas fueling stations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Impact of the Decontrol of Silver Concentrate Processing Trade on China’s Lead Market

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    In early June,two lead factories of Henan Jinli,and Yuguang Gold&Lead announced they have obtained silver concentrate Processing Handbook.Market analysts considered that decontrol on contract processing of silver ore will aggravate the pressure on lead ingot supply in China.

  6. Comparison of blood lead and blood and plasma δ-aminolevulinic acid concentrations as biomarkers for lead poisoning in cattle.

    Science.gov (United States)

    Kang, Hwan Goo; Bischoff, Karyn; Ebel, Joseph G; Cha, Sang Ho; McCardle, James; Choi, Cheong Up

    2010-11-01

    Lead (Pb) concentrations in whole blood and δ-aminolevulinic acid (ALA) concentrations in plasma and whole blood from 37 cattle with suspected Pb exposure were determined in order to investigate the usefulness of ALA as a biological indicator for Pb poisoning in cattle. Cows were divided into 4 groups based on blood Pb, as follows: ppb (group 1), 30-100 ppb (group 2), 100-300 ppb (group 3), and >300 ppb (group 4). The derivatization reaction for ALA was improved by a greater than 2-fold measure in whole blood and by a 10-fold measure in plasma by adding 75 and 50 µl of 0.1 N HCl, respectively. Blood Pb concentrations ranged from ppb to 1,006 ppb (185.5 ± 254.9 ppb), with 17 samples containing >50 ppb Pb. Delta-aminolevulinic acid concentrations in whole blood and plasma ranged from ppb to 96.9 ppb (77.4 ± 8.4 ppb) and from ppb to 24.0 ppb (4.6 ± 3.8 ppb), respectively. Whole blood ALA did not correlate with blood lead concentrations in any group. Increase in plasma ALA concentration was dependent on blood Pb concentration. There was no correlation between blood Pb concentration and plasma ALA concentration in group 2 (n  =  4), but correlation coefficients were 0.736 in group 3 and 0.807 in group 4, respectively. The correlation coefficient was increased to 0.851 when groups 3 and 4 were combined. Based on these observations, in cattle, plasma ALA is a more reliable biological biomarker for Pb exposure than is blood ALA.

  7. Lead concentration in meat from lead-killed moose and predicted human exposure using Monte Carlo simulation.

    Science.gov (United States)

    Lindboe, M; Henrichsen, E N; Høgåsen, H R; Bernhoft, A

    2012-01-01

    Lead-based hunting ammunitions are still common in most countries. On impact such ammunition releases fragments which are widely distributed within the carcass. In Norway, wild game is an important meat source for segments of the population and 95% of hunters use lead-based bullets. In this paper, we have investigated the lead content of ground meat from moose (Alces alces) intended for human consumption in Norway, and have predicted human exposure through this source. Fifty-two samples from different batches of ground meat from moose killed with lead-based bullets were randomly collected. The lead content was measured by atomic absorption spectroscopy. The lead intake from exposure to moose meat over time, depending on the frequency of intake and portion size, was predicted using Monte Carlo simulation. In 81% of the batches, lead levels were above the limit of quantification of 0.03 mg kg(-1), ranging up to 110 mg kg(-1). The mean lead concentration was 5.6 mg kg(-1), i.e. 56 times the European Commission limit for lead in meat. For consumers eating a moderate meat serving (2 g kg(-1) bw), a single serving would give a lead intake of 11 µg kg(-1) bw on average, with maximum of 220 µg kg(-1) bw. Using Monte Carlo simulation, the median (and 97.5th percentile) predicted weekly intake of lead from moose meat was 12 µg kg(-1) bw (27 µg kg(-1) bw) for one serving per week and 25 µg kg(-1) bw (45 µg kg(-1) bw) for two servings per week. The results indicate that the intake of meat from big game shot with lead-based bullets imposes a significant contribution to the total human lead exposure. The provisional tolerable weekly intake set by the World Health Organization (WHO) of 25 µg kg(-1) bw is likely to be exceeded in people eating moose meat on a regular basis. The European Food Safety Authority (EFSA) has recently concluded that adverse effects may be present at even lower exposure doses. Hence, even occasional consumption of big game meat with lead levels as

  8. Effectiveness of leaded petrol phase-out in Tianjin, China based on the aerosol lead concentration and isotope abundance ratio

    Energy Technology Data Exchange (ETDEWEB)

    Wang Wan [Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Liu Xiande [Chinese Research Academy of Environmental Sciences, Beijing 100012 (China)]. E-mail: liuxdlxd@hotmail.com; Zhao Liwei [Tianjin Environmental Monitoring Center, Tianjin, 300190 (China); Guo, Dongfa [Beijing Research Institute of Uranium Geology, Beijing 100029 (China); Tian Xiaodan [University of Antwerp, UA, B-2610 Wilrijk-Antwerpen (Belgium); Adams, Freddy [University of Antwerp, UA, B-2610 Wilrijk-Antwerpen (Belgium)

    2006-07-01

    The phase-out of leaded petrol has been a measure widely used to reduce atmospheric lead pollution. Since the 1980s, China began to promote unleaded petrol. In order to assess the effectiveness of the measure an isotope fingerprint technique was applied for aerosol samples in the city of Tianjin. After dilute acid leaching, the lead concentration and isotope abundance ratios were determined for 123 samples collected in Tianjin during eight years (1994-2001). The {sup 206}Pb / {sup 207}Pb ratio was lower in summer, when coal combustion emission was low and vehicle exhaust became more important, indicating that the {sup 206}Pb / {sup 207}Pb ratio of leaded petrol in Tianjin is lower than that of aerosol samples. The {sup 206}Pb / {sup 207}Pb ratio gradually increased from 1994 to 2001, a trend that suggests that the contribution from vehicle exhaust was diminishing. Overall, the measurements matched well with national statistical data of leaded and unleaded petrol production. After the nationwide switch to unleaded gasoline, comprehensive control measures are urgently needed to reduce air lead pollution in China, as aerosol lead reduced slightly but remains at a relatively high level.

  9. Effectiveness of leaded petrol phase-out in Tianjin, China based on the aerosol lead concentration and isotope abundance ratio

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wan; Liu, Xiande [Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Zhao, Liwei [Tianjin Environmental Monitoring Center, Tianjin, 300190 (China); Guo, Dongfa [Beijing Research Institute of Uranium Geology, Beijing 100029 (China); Tian, Xiaodan; Adams, Freddy [University of Antwerp, UA, B-2610 Wilrijk-Antwerpen (Belgium)

    2006-07-01

    The phase-out of leaded petrol has been a measure widely used to reduce atmospheric lead pollution. Since the 1980s, China began to promote unleaded petrol. In order to assess the effectiveness of the measure an isotope fingerprint technique was applied for aerosol samples in the city of Tianjin. After dilute acid leaching, the lead concentration and isotope abundance ratios were determined for 123 samples collected in Tianjin during eight years (1994-2001). The {sup 206}Pb/{sup 207}Pb ratio was lower in summer, when coal combustion emission was low and vehicle exhaust became more important, indicating that the {sup 206}Pb/{sup 207}Pb ratio of leaded petrol in Tianjin is lower than that of aerosol samples. The {sup 206}Pb/{sup 207}Pb ratio gradually increased from 1994 to 2001, a trend that suggests that the contribution from vehicle exhaust was diminishing. Overall, the measurements matched well with national statistical data of leaded and unleaded petrol production. After the nationwide switch to unleaded gasoline, comprehensive control measures are urgently needed to reduce air lead pollution in China, as aerosol lead reduced slightly but remains at a relatively high level. (author)

  10. Autism spectrum disorder prevalence and associations with air concentrations of lead, mercury, and arsenic.

    Science.gov (United States)

    Dickerson, Aisha S; Rahbar, Mohammad H; Bakian, Amanda V; Bilder, Deborah A; Harrington, Rebecca A; Pettygrove, Sydney; Kirby, Russell S; Durkin, Maureen S; Han, Inkyu; Moyé, Lemuel A; Pearson, Deborah A; Wingate, Martha Slay; Zahorodny, Walter M

    2016-07-01

    Lead, mercury, and arsenic are neurotoxicants with known effects on neurodevelopment. Autism spectrum disorder (ASD) is a neurodevelopmental disorder apparent by early childhood. Using data on 4486 children with ASD residing in 2489 census tracts in five sites of the Centers for Disease Control and Prevention's Autism and Developmental Disabilities Monitoring (ADDM) Network, we used multi-level negative binomial models to investigate if ambient lead, mercury, and arsenic concentrations, as measured by the US Environmental Protection Agency National-Scale Air Toxics Assessment (EPA-NATA), were associated with ASD prevalence. In unadjusted analyses, ambient metal concentrations were negatively associated with ASD prevalence. After adjusting for confounding factors, tracts with air concentrations of lead in the highest quartile had significantly higher ASD prevalence than tracts with lead concentrations in the lowest quartile (prevalence ratio (PR) = 1.36; 95 '% CI: 1.18, 1.57). In addition, tracts with mercury concentrations above the 75th percentile (>1.7 ng/m(3)) and arsenic concentrations below the 75th percentile (≤0.13 ng/m(3)) had a significantly higher ASD prevalence (adjusted RR = 1.20; 95 % CI: 1.03, 1.40) compared to tracts with arsenic, lead, and mercury concentrations below the 75th percentile. Our results suggest a possible association between ambient lead concentrations and ASD prevalence and demonstrate that exposure to multiple metals may have synergistic effects on ASD prevalence.

  11. Association of prenatal and childhood blood lead concentrations with criminal arrests in early adulthood.

    Directory of Open Access Journals (Sweden)

    John Paul Wright

    2008-05-01

    Full Text Available BACKGROUND: Childhood lead exposure is a purported risk factor for antisocial behavior, but prior studies either relied on indirect measures of exposure or did not follow participants into adulthood to examine the relationship between lead exposure and criminal activity in young adults. The objective of this study was to determine if prenatal and childhood blood lead concentrations are associated with arrests for criminal offenses. METHODS AND FINDINGS: Pregnant women were recruited from four prenatal clinics in Cincinnati, Ohio if they resided in areas of the city with a high concentration of older, lead-contaminated housing. We studied 250 individuals, 19 to 24 y of age, out of 376 children who were recruited at birth between 1979 and 1984. Prenatal maternal blood lead concentrations were measured during the first or early second trimester of pregnancy. Childhood blood lead concentrations were measured on a quarterly and biannual basis through 6.5 y. Study participants were examined at an inner-city pediatric clinic and the Cincinnati Children's Hospital Medical Center in Cincinnati, Ohio. Total arrests and arrests for offenses involving violence were collected from official Hamilton County, Ohio criminal justice records. Main outcomes were the covariate-adjusted rate ratios (RR for total arrests and arrests for violent crimes associated with each 5 microg/dl (0.24 micromol/l increase in blood lead concentration. Adjusted total arrest rates were greater for each 5 microg/dl (0.24 micromol/l increase in blood lead concentration: RR = 1.40 (95% confidence interval [CI] 1.07-1.85 for prenatal blood lead, 1.07 (95% CI 0.88-1.29 for average childhood blood lead, and 1.27 (95% CI 1.03-1.57 for 6-year blood lead. Adjusted arrest rates for violent crimes were also greater for each 5 microg/dl increase in blood lead: RR = 1.34 (95% CI 0.88-2.03 for prenatal blood lead, 1.30 (95% CI 1.03-1.64 for average childhood blood lead, and 1.48 (95% CI 1

  12. The lead accumulation and hematological findings in juvenile rock fish Sebastes schlegelii exposed to the dietary lead (II) concentrations.

    Science.gov (United States)

    Kim, Jun-Hwan; Kang, Ju-Chan

    2015-05-01

    Juvenile rockfish (mean length 14.2 ± 1.9 cm, and mean weight 57.3 ± 5.2g) were exposed for 4 weeks with the different levels of dietary lead (Pb(2+)) at 0, 30, 60, 120 and 240 mg/L. The exposure concentration and period of Pb have induced significant amount of it the specific tissues of rockfish. The highest Pb accumulation was observed in the kidney tissue by the dietary lead exposure. The growth rate and hepatosomatic index were considerably inhibited over 120 mg/kg. The hematological parameters such as red blood cell (RBC) counts, hematocrit (Ht) value, and hemoglobin (Hb) concentration were significantly decreased over 60 mg/kg Pb concentration. In the inorganic components, the values of calcium and magnesium in plasma were significantly decreased. The glucose and cholesterol values were notably increased, whereas total protein was decreased. The enzyme components, glutamic oxalate transaminase (GOT) and glutamic pyruvate transaminase (GPT), were significantly elevated by the dietary lead exposure, but no change was observed in alkaline phosphatase (ALP).

  13. Deficits in cognitive function and achievement in Mexican first-graders with low blood lead concentrations.

    Science.gov (United States)

    Kordas, Katarzyna; Canfield, Richard L; López, Patricia; Rosado, Jorge L; Vargas, Gonzalo García; Cebrián, Mariano E; Rico, Javier Alatorre; Ronquillo, Dolores; Stoltzfus, Rebecca J

    2006-03-01

    Elevated blood lead levels in children are associated with lower scores on tests of cognitive functioning. Recent studies have reported inverse relations between lifetime exposure and intellectual functioning at blood lead concentrations below 10 microg/dL, the Centers for Disease Control and Prevention's (CDC) level of concern. We report associations between blood lead and cognitive performance for first-grade Mexican children living near a metal foundry. Using a cross-sectional design, we examined the relation between children's concurrent blood lead concentrations (mean (SD) 11.4 microg/dL (6.1)) and their performance on 14 tests of global or specific cognitive functions. The blood lead-cognition relations were modeled using both linear and nonlinear methods. After adjustment for covariates, a higher blood lead level was associated with poorer cognitive performance on several cognitive tests. Segmented linear regressions revealed significant effects of lead but only for the segments defined by a concurrent blood lead concentration below 10-14 microg/dL. One implication of these findings is that at the age of 7 years, even in the absence of information on lead exposure in infancy and early childhood, a test result with blood lead < 10 microg/dL should not be considered safe. Together with other recent findings, these results add to the empirical base of support available for evaluating the adequacy of current screening guidelines and for motivating efforts at primary prevention of childhood lead exposure.

  14. The effect of lead and zinc concentrations on the growth of four ...

    African Journals Online (AJOL)

    The effect of lead and zinc concentrations on the growth of four species of bryophytes. ... duration, intensity of precipitation and plant species affect accumulation of heavy metal. ... International Journal of Biological & Chemical Sciences Vol.

  15. Impact of low blood lead concentrations on IQ and school performance in Chinese children.

    Directory of Open Access Journals (Sweden)

    Jianghong Liu

    Full Text Available Examine the relationships between blood lead concentrations and children's intelligence quotient (IQ and school performance.Participants were 1341 children (738 boys and 603 girls from Jintan, China. Blood lead concentrations were measured when children were 3-5 years old. IQ was assessed using the Chinese version and norms of the Wechsler Preschool and Primary Scale of Intelligence - Revised when children were 6 years old. School performance was assessed by standardized city tests on 3 major subjects (Chinese, Math, and English [as a foreign language] when children were age 8-10 years.Mean blood lead concentration was 6.43 µg/dL (SD = 2.64. For blood lead concentrations, 7.8% of children (n = 105 had ≥10.0 µg/dL, 13.8% (n = 185 had 8.0 to <10.0 µg/dL, and 78.4% (n = 1051 had <8.0 µg/dL. Compared to children with blood lead concentrations <8 µg/dL, those with blood lead concentrations ≥8 µg/dL scored 2-3 points lower in IQ and 5-6 points lower in school tests. There were no significant differences in IQ or school tests between children with blood lead concentrations groups 8-10 and ≥10 µg/dL. After adjustment for child and family characteristics and IQ, blood lead concentrations ≥10 µg/dL vs <8 µg/dL at ages 3-5 years was associated with reduced scores on school tests at age 8-10 years (Chinese, β = -3.54, 95%CI = -6.46, -0.63; Math, β = -4.63, 95%CI = -7.86, -1.40; English, β = -4.66, 95%CI = -8.09, -1.23. IQ partially mediated the relationship between elevated blood lead concentrations and later school performance.Findings support that blood lead concentrations in early childhood, even <10 µg/dL, have a long-term negative impact on cognitive development. The association between blood lead concentrations 8-10 µg/dL and cognitive development needs further study in Chinese children and children from other developing countries.

  16. Sulfide precursor concentration and lead source effect on PbS thin films properties

    Energy Technology Data Exchange (ETDEWEB)

    Beddek, L.; Messaoudi, M.; Attaf, N. [Laboratoire Couche Minces et Interfaces, Université frères Mentouri Constantine, 25000, Constantine (Algeria); Aida, M.S., E-mail: aida_salah2@yahoo.fr [Laboratoire Couche Minces et Interfaces, Université frères Mentouri Constantine, 25000, Constantine (Algeria); Bougdira, J. [Université de Lorraine, Institut Jean Lamour UMR 7198, Vandoeuvre 54506 (France)

    2016-05-05

    Lead sulfide (PbS) thin films were synthesized using chemical bath deposition (CBD). Bath solutions are formed of various concentrations of thiourea, sulfide source, ranged from 0.6 to 1.2 M and two different salts as Pb source (lead acetate and lead nitrate). From the growth mechanism, we inferred that PbS is formed through the ion by ion process when using acetate lead source, while, using nitrate source yields to films growth through the complex-decomposition process. Due to the difference in the involved growth process, lead acetate produces films with larger crystallite size (from 4 to 16 nm), smooth and dense films. However, lead nitrate produces rough films with smaller crystallite size (from 1 to 4 nm). Increasing the thiourea concentration results in crystallinity improvement when using lead acetate and, oppositely, in crystallinity degradation when using lead nitrate. Due to the quantum effect caused by the small crystallite sizes, the films optical gap is varied from 0.5 to 0.9 eV. - Highlights: • PbS thin films were synthesized by chemical bath deposition. • Ion by ion is the growth process when using the acetate lead source. • Deposition process is by complex-decomposition when using nitrate source. • Lead acetate yields to dense films with larger crystallite size. • Lead nitrate produces rough films with smaller crystallite size.

  17. Temporal variations in lead concentrations and isotopic composition in the Southern California Bight

    Energy Technology Data Exchange (ETDEWEB)

    Sanudo-Wilhelmy, S.A.; Flegal, A.R. (Univ. of California, Santa Cruz, CA (United States))

    1994-08-01

    Lead concentrations in surface waters of the Southern California Bight appear to have decreased threefold (from >170 to <60 pM) since they were initially measured by Clair Patterson and his associates in the 1970s. The decrease parallels a threefold decline in anthropogenic inputs of industrial lead to the bight over the past two decades. Moreover, mass balance calculations indicate that the primary source of lead to the bight now is upwelling. This is evidenced by the isotopic compositions of surface waters in the bight, which are most characteristic of Asian industrial lead aerosols (0.4793 [le] [sup 206]Pb/[sup 208]Pb [le] 0.4833) deposited in oceanic waters of the North Pacific. While the decrease in surface water lead concentrations in the bight reflects the reduction in industrial lead emissions from the United States, the isotopic compositions of surface waters in the southern reach of the bight reflect a concurrent increase in industrial lead emissions from Mexico (0.4852 [le] [sup 206]Pb/[sup 208]Pb [le] 0.4877). The isotopic composition ([sup 208]Pb/[sup 207]Pb [approximately] 2.427) of elevated lead concentrations of surface waters in San Diego Bay indicate that lead is being remobilized from contaminated sediments within that bay.

  18. Influence of paint chips on lead concentration in the soil of public playgrounds in Tokyo.

    Science.gov (United States)

    Takaoka, Michie; Yoshinaga, Jun; Tanaka, Atsushi

    2006-03-01

    Lead concentration in the surface soils from 31 playgrounds in a ward in Tokyo was measured to examine if paint chips, peeled off from playing equipment installed in the playgrounds, contribute to elevated Pb concentration in the soil of public playgrounds. Lead concentration in the paint chips sampled from playgrounds ranged from 0.003 to 8.9%. Lead concentration in the surface soil ranged from 15.2 to 237 mg kg(-1) (average, 55.5 mg kg(-1)) and higher Pb concentration was found in the soil near painted playing equipment indicating that paint chips from playing equipment contributed to increase soil Pb level of playgrounds in Tokyo. The degree of peeling-off of paint on the surface of playing equipment in the public playground (peeling-off index: POI) positively correlated with Pb concentration in the soil (Spearman rank-correlation coefficient, r = 0.366, p = 0.043). The stronger correlation between Pb concentration and isotope ratios (207Pb/206Pb and Pb conc., r = 0.536, p = 0.002, 208Pb/206Pb and Pb conc. r = 0.600, p playground-to-playground variation in soil Pb concentration. It was concluded that both gasoline Pb of the past and paint chips contributed to increased Pb concentration in the surface soil of playgrounds in Tokyo, though the contribution of paint chips is smaller than gasoline Pb.

  19. Correlation between blood lead concentration and iron deficiency in Iranian children

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Keramati

    2013-01-01

    Full Text Available Background: Iron deficiency anaemia is the most common nutritional anaemia among children. Lead toxicity is a serious health threat, especially in developing countries due to environmental pollution. It was thus aimed to investigate correlation between blood lead concentration and iron deficiency in children of Mashhad, Iran. Materials and Methods: This cross sectional study was performed on children between 1 year and 10 years, in Imam Reza teaching hospital of Mashhad, Iran, in 2010. Indeed during complete blood count (CBC, we measured iron and total iron binding capacity (TIBC by colorimetric methods, ferritin by radioimmune assay and blood lead concentration by atomic absorption method. Results were analysed by Statistical Package for Social Sciences (SPSS (version 11.5, using statistical tests including independent sample t-test, Mann-Whitney U test, Spearman′s test and analysis of variance (ANOVA and Pearson′s or Spearman′s correlation coefficient. P value ≤ 0.05 was considered as a significant level. Results: We studied 223 cases including 98 control children and 125 patients. All children had lead intoxication. Mean (±SD blood lead concentration in the control group was 57.1 ± 25.3 (ranged 20-212 μg/dl and in the patient group was 57 ± 20.4 (ranged 10.9-159 μg/dl with no significant difference (P value = 0.713. We also did not find any correlation between blood lead concentration and haemoglobin, ferritin, iron, TIBC, mean corpuscular volume (MCV, mean corpuscular haemoglobin (MCH, mean corpuscular haemoglobin concentration (MCHC, white blood cells (WBC and platelets. Conclusion: Based on these results, no correlation was found between blood lead concentration and iron deficiency in the children. Because all children had lead intoxication, further studies in highly polluted and a comparison with a low polluted area are necessary to make a general conclusion.

  20. Concentration of Lead, Mercury, Cadmium, Aluminum, Arsenic and Manganese in Umbilical Cord Blood of Jamaican Newborns

    Directory of Open Access Journals (Sweden)

    Mohammad H. Rahbar

    2015-04-01

    Full Text Available The objective of this study was to characterize the concentrations of lead, mercury, cadmium, aluminum, and manganese in umbilical cord blood of Jamaican newborns and to explore the possible association between concentrations of these elements and certain birth outcomes. Based on data from 100 pregnant mothers and their 100 newborns who were enrolled from Jamaica in 2011, the arithmetic mean (standard deviation concentrations of cord blood lead, mercury, aluminum, and manganese were 0.8 (1.3 μg/dL, 4.4 (2.4 μg/L, 10.9 (9.2 μg/L, and 43.7 (17.7 μg/L, respectively. In univariable General Linear Models, the geometric mean cord blood aluminum concentration was higher for children whose mothers had completed their education up to high school compared to those whose mothers had any education beyond high school (12.2 μg/L vs. 6.4 μg/L; p < 0.01. After controlling for maternal education level and socio-economic status (through ownership of a family car, the cord blood lead concentration was significantly associated with head circumference (adjusted p < 0.01. Our results not only provide levels of arsenic and the aforementioned metals in cord blood that could serve as a reference for the Jamaican population, but also replicate previously reported significant associations between cord blood lead concentrations and head circumference at birth in other populations.

  1. Total lead concentration in new decorative enamel paints in Lebanon, Paraguay and Russia.

    Science.gov (United States)

    Clark, C Scott; Speranskaya, Olga; Brosche, Sara; Gonzalez, Hebe; Solis, Daniela; Kodeih, Naji; Roda, Sandy; Lind, Caroline

    2015-04-01

    Lead concentrations in new enamel decorative paints were determined in three countries in different areas of the world where data were not previously available. The average total lead concentration of the enamel decorative paints purchased in Lebanon, Paraguay and Russia was 24,500ppm (ppm, dry weight), more than 270 times the current limit of 90ppm in Canada and in the United States. Sixty-three percent of these paints contained concentrations greater than 90ppm. Fifty-nine percent contained concentrations greater than 600ppm, the current limit in some countries. The maximum concentrations found were 236,000ppm in Lebanon, 169,000ppm in Paraguay and 52,900ppm in Russia. An average of 29% of the samples contained exceedingly high lead concentrations, >=10,000ppm. Five brands of paint were sampled in each of Lebanon and Paraguay and seven in Russia. Three colors from each brand were analyzed. For five of the six samples of the two brands in Lebanon with affiliations outside the country, the lead concentrations ranged from 1360ppm to 135,000ppm. In Lebanon the maximum concentration in the Egypt-affiliated brand (Sipes) was 135,000ppm and the maximum for the USA-affiliated brand (Dutch Boy) was 32,400ppm. Lead was not detected in any paints from the three of the four brands of paint purchased in Paraguay that had headquarters/affiliations in other countries (Brazil-Coralit), Germany (Suvinil) and USA (Novacor)). Two of the three paints from each of the other Paraguay brands contained high levels of lead with the maximum concentrations of 108,000 and 168,000ppm; one of these brands was manufactured under a license from ICI in the Netherlands. All of the paints purchased in Russia were from Russian brands and were manufactured in Russia. All three paints from one brand contained below detection levels of lead. The maximum levels of lead in the other six brands in Russia ranged from 3230 to 52,900ppm. The two brands with the highest lead concentration, TEKS and LAKRA

  2. Blood Lead Concentrations in Jamaican Children with and without Autism Spectrum Disorder

    Science.gov (United States)

    Rahbar, Mohammad H.; Samms-Vaughan, Maureen; Dickerson, Aisha S.; Loveland, Katherine A.; Ardjomand-Hessabi, Manouchehr; Bressler, Jan; Shakespeare-Pellington, Sydonnie; Grove, Megan L.; Pearson, Deborah A.; Boerwinkle, Eric

    2014-01-01

    Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder manifesting by early childhood. Lead is a toxic metal shown to cause neurodevelopmental disorders in children. Several studies have investigated the possible association between exposure to lead and ASD, but their findings are conflicting. Using data from 100 ASD cases (2–8 years of age) and their age- and sex-matched typically developing controls, we investigated the association between blood lead concentrations (BLC) and ASD in Jamaican children. We administered a questionnaire to assess demographic and socioeconomic information as well as exposure to potential lead sources. We used General Linear Models (GLM) to assess the association of BLC with ASD status as well as with sources of exposure to lead. In univariable GLM, we found a significant difference between geometric mean blood lead concentrations of ASD cases and controls (2.25 μg/dL cases vs. 2.73 μg/dL controls, p lead concentrations of ASD cases and controls (2.55 μg/dL vs. 2.72 μg/dL, p = 0.64). Our results do not support an association between BLC and ASD in Jamaican children. We have identified significant confounders when assessing an association between ASD and BLC. PMID:25546274

  3. Lead Concentration in Primary School Soil-Dust in Nigeria, Africa

    Directory of Open Access Journals (Sweden)

    Ekwumemgbo P. A.

    2013-04-01

    Full Text Available Lead in soil has been recognized as a public health problem, particularly among children. In recent years, attention has been directed to cumulative adverse effects of lead at low levels of intake. Leadcontaminated soil and dust have been identified as important contributors to blood lead levels. This work examines the total concentration of lead in primary school soil-dust in Nigeria. Soil-dusts were collected randomly from six geopolitical areas of Nigeria, digested and analysed for total lead concentration by Atomic Absorption Spectrophotometry. The mean lead concentration in the dry season for the North East (NE, North West (NW, North Central (NC, South South (SS, South East (SE, South West (SW were 131.60 ± 70.98 mg/kg, 108.04 ± 47.33 mg/kg, 72.94 ± 55.45 mg/kg, 66.14 ± 43.9 mg/kg, 45.98 ± 34.60 mg/kg and 67.98 ± 34.89 mg/kg respectively. In the raining season the mean lead concentration were 130.78 ± 70.80 mg/kg, 106.24 ± 47.02 mg/kg, 70.96 ± 55.52 mg/kg, 64.12 ± 48.00 mg/kg, 44.58 ± 28.90 mg/kg, and 66.26 ± 41.87 mg/kg respectively. This analysis is necessary to provide scientific data base for the loading of lead in classroom soil-dust in each zone. The authors recommend measurement and surveillance of lead blood level of the primary school children and a clean-up of both classrooms and the school environment.

  4. Temporal Variations in Surface Concentrations of Terrestrial Lead 210 and Uranium 235 Radionucleides

    Science.gov (United States)

    Yoshimori, M.

    We have started to measure the surface concentrations of terrestrial radionucleides of lead 210 and uranium 235 in Tokyo (N35, E139) in 2002. Lead 210 which is a daughter nucleus of Rn-222 (uranium series) emits 46 keV gamma-ray with a half-life of 22.4 years, while uranium 235 (actinium series) emits a gamma-ray at 186 keV with a half-life of 0.7 billion years. The present measurement of the surface concentration of lead 210 exhibits two peaks in spring and fall, similar to the beryllium 7 seasonal variations, while the uranium 235 concentration does not vary with time within statistical errors. These two terrestrial radionucleides exhibit different temporal variations on the surface. We discuss possible explanations for the differences in the temporal variations from a point of view of differences in their altitude distribution.

  5. Liver lead concentrations in raptors in New Jersey, USA, 2008-2010.

    Science.gov (United States)

    Stansley, William; Murphy, Lisa A

    2011-08-01

    Lead exposure in New Jersey raptors was assessed by analyzing liver samples from carcasses obtained from wildlife rehabilitators. Samples were collected from 221 individuals representing 13 species. Concentrations were within the range of normal background exposure in 12 species. One red-tailed hawk had a liver lead concentration consistent with clinical poisoning (7.4 μg/g wet weight), which represents an incidence of 1% (1/104) in that species and 0.5% (1/221) in the overall sample. A second red-tailed hawk had a liver lead concentration consistent with subclinical exposure (2.1 μg/g wet weight). The combined incidence of elevated exposure (subclinical exposure + clinical poisoning) was 2% (2/104) in red-tailed hawks and 1% (2/221) in the overall sample.

  6. Exposure to a Low Lead Concentration Impairs Contractile Machinery in Rat Cardiac Muscle.

    Science.gov (United States)

    Silva, Marito A S C; de Oliveira, Thiago F; Almenara, Camila C P; Broseghini-Filho, Gilson B; Vassallo, Dalton V; Padilha, Alessandra S; Silveira, Edna A

    2015-10-01

    Lead exposure has been considered to be a risk factor for hypertension and cardiovascular disease. Our purpose was to evaluate the effects of low plasma lead concentration on cardiac contractility in isolated papillary muscles. Wistar rats were divided in control group or group treated with 100 ppm of lead acetate in the drinking water for 15 days. Blood pressure (BP) was measured weekly. At the end of the treatment period, the animals were anesthetized and euthanized, and parameters related to isolated papillary muscle contractility were recorded. The lead concentrations in the blood reached 12.3 ± 2 μg/dL. The BP was increased in the group treated with 100 ppm of lead acetate. Lead treatment did not alter force and time derivatives of the force of left ventricular papillary muscles. In addition, the inotropic response induced by an increase in the extracellular Ca(2+) concentration was reduced in the Pb(2+) group. However, the uptake of Ca(2+) by the sarcoplasmic reticulum and the protein expression of SERCA and phospholamban remained unchanged. Postrest contraction was similar in the both groups, and tetanic peak and plateau tension were reduced in lead group. These results demonstrated that the reduction in the inotropic response to calcium does not appear to be caused by changes in the trans-sarcolemmal calcium flux but suggest that an impairment of the contractile machinery might be taking place. Our results demonstrate that even at a concentration below the limit considered to be safe, lead exerts deleterious effects on the cardiac contractile machinery.

  7. Effect of polysulfone concentration on the performance of membrane-assisted lead acid battery

    OpenAIRE

    Ahmad Fauzi Ismail; Wan Ahmad Hafiz

    2002-01-01

    The application of lead acid battery in tropical countries normally faces the problem of water decomposition. This phenomenon is due to the factor of charge-discharge reaction in the battery and heat accumulation caused by hot tropical climate and heat generated from engine compartment. The objective of this study is to analyze the effect of polysulfone concentration on the performance of membrane-assisted lead-acid battery. Gas separation membranes, prepared through wet-dry phase inversion m...

  8. Concentration and environmental significance of lead in surface snow of Antarctic ice sheet (III)

    Institute of Scientific and Technical Information of China (English)

    秦大河; 任贾文; 孙俊英; 陈瓞延; 文克玲; 李良权

    1995-01-01

    Lead as an ultra-trace heavy metal becomes one of popular topics in glaciochemistry of the Antarctic ice sheet, because of its very low concertration (pg·g-1) and background and its sensitivity to the quality of the environment. The lead concentration of surface snow of the Antarctic ice sheet (corresponding to modern precipitation) applying LEAF technique by Chinese scholars has systematically been studied for the first time in the world. The distribution principle of lead concentration of surface snow of the Antarctic ice sheet is "low in the west and high in the east" along the route of 1990 International Trans-Antarctic Expedition (ITAE). The concentration of lead in East Antarctica is 2 - 3 fold higher than that in Larsen ice shelf and Antarctic Peninsula, which majorly results from the activity of pre-Soviet Antarctic Expedition The concentration of lead in Larsen ice shelf and Antarctic Peninsula can be regarded as the background value of modern precipitation of the Antarctic ice sheet in the en

  9. Leaching Mechanism of Complicated Antimony-Lead Concentrate and Sulfur Formation in Slurry Electrolysis

    Institute of Scientific and Technical Information of China (English)

    WangChengyan; QiuDingfan; JiangPeihai

    2004-01-01

    Anodic reaction mechanism of complicated antimony-lead concentrate in slurry electrolysis was investigated by the anodic polarization curves determined under various conditions. The main reactions on the anode are the oxidations of FeCln(2-n) . Though the oxidation of jamesonite particle on the anode can occur during the whole process, it is less. With the help of mineralogy studies and relevant tests, the leaching reaction mechanism of jameson[to and gudmundite during slurry electrolysis was ascertained. Because of the oxidation reaction of FeCl3 produced by antimony-lead concentrate itself, the non-oxidation complex acid dissolution of jameson[re, the oxidation complex acid dissolution of gudmundite, and the oxidation of air carried by stirring, the leaching ratio of antimony reaches about 35% when HCl-NH4Cl solution is used to leach antimony-lead concentrate directly. So when the theoretical electric quantity is given to oxidation of antimony in slurry electrolysis, all of antimony, lead and iron containing in antimony-lead concentrate, are leached. The formation of sulfur is through the directly redox reaction of Fe3+ and jameson[re. The S2- in jamesonite is oxidized into S0 , and forms the crystals of sulfur again on the spot. The redox reaction of Fe3+ and H2S formed by non-oxidative acid dissolution of jamesonite is less.

  10. Lead uptake and the effects of EDTA on lead-tissue concentrations in the desert species mesquite (Prosopis spp.).

    Science.gov (United States)

    Aldrich, M V; Ellzey, l J T; Peralta-Videa, J R; Gonzalez, J H; Gardea-Torresdey, J L

    2004-01-01

    Experimental results have shown that the desert plant species mesquite (Prosopis spp.) is capable of accumulating high levels of lead in the roots, translocating it to the aerial portion of the plant. One-week-old mesquite seedlings were treated for 7 d in a hydroponic culture using a modified Hoagland solution. Six treatments were used; three treatments contained only Pb [as Pb(NO3)2] at 25-, 50-, and 75-mg L(-1) levels and three treatments contained the same levels of Pb, but with equimolar concentrations of disodium ethylenediamine tetraacetic acid (EDTA). Our results showed that the plants exposed to 25-, 50-, and 75-mg Pb L(-1) treatments without EDTA concentrated in stems 524, 3726, and 1417 mg kg(-1), respectively. However, the plants treated with Pb-EDTA concentrated in stems 480-, 607-, and 1247-mg Pb kg(-1) for the 25-, 50-, and 75-mg Pb L(-1) treatments, respectively. Results for the roots followed a similar trend; without EDTA the Pb levels ranged from 16,055, 89,935, and 63,396 for the 25-, 50-, and 75-mg Pb L(-1) treatments, respectively, and with EDTA these levels were 9,562, 49,902, and 39,181 mg kg(-1) for the three treatments. However, the addition of EDTA increased lead movement to the leaves. The levels of Pb without EDTA were 20, 35, and 51 mg kg(-1) for the 25-, 50-, and 75-mg Pb L(-1) levels, respectively. Treatments with EDTA showed uptake levels of 105, 124, and 313 for the 25-, 50-, and 75-mg Pb L(-1) treatments. Further, the percent Pb in dry leaf tissues for all EDTA treatments were greater than 0.1%. However, only the 25-mg Pb L(-1) treatment was greater than 0.1%, compared to 0.04 and 0.08% for the 50- and 75-mg Pb L(-1) treatments, respectively. Preliminary transmission and scanning electron microscopy corroborate the presence of lead.

  11. Mutagenesis of AS52 cells by low concentrations of lead(II) and mercury(II)

    Science.gov (United States)

    Ariza, M E; Williams, M V

    1996-01-01

    Little is known at the molecular level concerning the genotoxic effects following the acute exposure of eukaryotic cells to low concentrations of lead (II) or mercury (II). There have been conflicting reports concerning the mutagenic potential of these heavy metals, and there have not been any studies performed to determine the molecular mechanism(s) by which these metals are mutagenic. The Chinese hamster ovary cell line, AS52, contains a stably integrated single functional copy of the Escherichia coli xanthine-guanine phosphoribosyltransferase (gpt) gene. Mutations in the gpt gene confer resistance to 6-thioguanine (TG). There was little effect on viability, as measured by relative cloning efficiency, of AS52 cells exposed to lead (II) or mercury (II) up to concentrations of 0.5 microM and 0.3 microM, respectively. However, higher concentrations of the metals caused a significant increase in cell death. There was also a dose-dependent increase in the isolation of mutants resistant to TG in treated cells when compared to non-treated controls. Concentrations of the metals as low as 0.1 microM caused a significant increase in the number of mutants resistant to TG when compared to the number of spontaneous mutants obtained in nontreated controls. While the molecular mechanism(s) by which lead and mercury (II) are genotoxic is unknown, the results of this study demonstrate that low concentrations of lead (II) and mercury (II) are mutagenic in eukaryotic cells.

  12. Application of lead and strontium isotope ratio measurements for the origin assessment of uranium ore concentrates.

    Science.gov (United States)

    Varga, Zsolt; Wallenius, Maria; Mayer, Klaus; Keegan, Elizabeth; Millet, Sylvain

    2009-10-15

    Lead and strontium isotope ratios were used for the origin assessment of uranium ore concentrates (yellow cakes) for nuclear forensic purposes. A simple and low-background sample preparation method was developed for the simultaneous separation of the analytes followed by the measurement of the isotope ratios by multicollector inductively coupled plasma mass spectrometry (MC-ICPMS). The lead isotopic composition of the ore concentrates suggests applicability for the verification of the source of the nuclear material and by the use of the radiogenic (207)Pb/(206)Pb ratio the age of the raw ore material can be calculated. However, during data interpretation, the relatively high variation of the lead isotopic composition within the mine site and the generally high contribution of natural lead as technological contamination have to be carefully taken into account. The (87)Sr/(86)Sr isotope ratio is less prone to the variation within one mine site and less affected by the production process, thus it was found to be a more purposeful indicator for the origin assessment and source verification than the lead. The lead and strontium isotope ratios measured and the methodology developed provide information on the initial raw uranium ore used, and thus they can be used for source attribution of the uranium ore concentrates.

  13. Concentrations of polonium-210 and lead-210 in soil of the Shu river valley

    Directory of Open Access Journals (Sweden)

    Ilona Matveyeva

    2012-03-01

    Full Text Available Radioecological inspection of the Shu river valley is spent. Concentration of polonium-210 in soil makes no more than 33 Bk/kg and lead-210 - no more than 41 Bk/kg. By a method of mathematical modelling it is shown, activity investigated radionuclides in Shu river water during 50 years after pollution does not exceed maximum permissible level.

  14. Lead

    Science.gov (United States)

    ... found? Who is at risk? What are the health effects of lead? Get educational material about lead Get certified as a Lead Abatement Worker, or other abatement discipline Lead in drinking water Lead air pollution Test your child Check and maintain your home ...

  15. Impact of electronic waste disposal on lead concentrations in landfill leachate.

    Science.gov (United States)

    Spalvins, Erik; Dubey, Brajesh; Townsend, Timothy

    2008-10-01

    Lead is the element most likely to cause discarded electronic devices to be characterized as hazardous waste. To examine the fate of lead from discarded electronics in landfills, five columns were filled with synthetic municipal solid waste (MSW). A mix of electronic devices was added to three columns (6% by weight), while two columns served as controls. A sixth column contained waste excavated from an existing MSW landfill. Leachate quality was monitored for 440 days. In columns with the synthetic waste, leachate pH indicated that the simulated landfill environment was characteristic of the acid phase of waste decomposition; lead leachability should be greater in the acid phase of landfill degradation as compared to the methanogenic phase. Lead concentrations ranged from 7 to 66 microg/L in the columns containing electronic waste and ranged from electronic devices were greater than those in the controls, the difference was not found to be statistically significant when comparing the data sets over the entire monitoring period. Lead results from the excavated waste column suggest that lead concentrations in all columns will decrease as the pH increases toward more neutral methanogenic conditions.

  16. Blood lead exposure concentrations in mottled ducks (Anas fulvigula) on the upper Texas coast

    Science.gov (United States)

    McDowell, Stephen K.; Conway, Warren C.; Haukos, David A.; Moon, Jena A.; Comer, Christopher E.; Hung, I-Kuai

    2015-01-01

    The mottled duck (Anas fulvigula) is a non-migratory waterfowl species dependent upon coastal marsh systems, including those on the Texas Chenier Plain National Wildlife Refuge (NWR) Complex, and considered a regional indicator species of marsh habitat quality. Research from the early 1970s, 1990s, and early-2000s indicated that mottled ducks continued to exhibit elevated wing-bone lead (Pb) concentrations, decades after implementation of non-toxic shot regulations. However, wing-bone concentrations reflect lifetime accumulation of Pb, whereas blood Pb concentrations reflect more recent exposure. To identify current potentially relevant temporal windows of Pb exposure, we collected 260 blood samples from mottled ducks during summer (n=124) and winter (n=136) from 2010–2012 on the Texas Chenier Plain NWR Complex. We quantified baseline blood Pb concentrations for all ages of mottled ducks, and hypothesized that blood lead concentrations would remain elevated above background levels (200 µg L–1) despite the 1983 and 1991 lead shot bans. Blood Pb concentrations ranged from below detection limits to >12,000 µg L–1, where >200 µg L–1 was associated with exposure levels above background concentrations. Male mottled ducks had the greatest blood Pb concentrations (30 times greater than females) with concentrations greater during winter than summer. Likewise, the proportion of exposed (>200 µg L–1) females increased from 14%–47% from summer to winter, respectively. Regardless of sex, adult mottled duck blood Pb concentrations were five times greater than juveniles, particularly during winter. We identified five plausible models that influenced blood Pb levels where year, site, and interactions among age*sex*season and between age*season were included in the top-ranked models. Frequency of exposure was greatest during winter, increasing from 12% in summer to 55% in winter, indicating that a temporal exposure window to environmental Pb exists between nesting

  17. Blood lead concentrations in free-ranging Nile crocodiles (Crocodylus niloticus) from South Africa.

    Science.gov (United States)

    Warner, Jonathan K; Combrink, Xander; Myburgh, Jan G; Downs, Colleen T

    2016-07-01

    Generally crocodilians have received little attention with regard to the effects of lead toxicity despite their trophic status as apex, generalist predators that utilize both aquatic and terrestrial habitats, thereby exposing them to a potentially wide range of environmental contaminants. During July-October 2010 we collected whole blood from 34 sub-adult and adult free-ranging Nile crocodiles (Crocodylus niloticus) from three separate populations in northeastern South Africa in order to analyze their blood lead concentrations (BPb). Concentrations ranged from below detectability (crocodile size and population sampled. On average, crocodiles had higher BPbs at Lake St Lucia than at Ndumo Game Reserve or Kosi Bay, which we attribute to lead sinker ingestion during normal gastrolith acquisition. No clinical effects of lead toxicosis were observed in these crocodiles, even though the highest concentration (960 μg/dL) we report represents the most elevated BPb recorded to date for a free-ranging vertebrate. Although we suggest adult Nile crocodiles are likely tolerant of elevated Pb body burdens, experimental studies on other crocodilian species suggest the BPb levels reported here may have harmful or fatal effects to egg development and hatchling health. In light of recent Nile crocodile nesting declines in South Africa we urge further BPb monitoring and ecotoxicology research on reproductive females and embryos.

  18. Lead Concentration Levels in Water Samples Collected in Alameda County, CA

    Science.gov (United States)

    Sethy, D.; Hoang, R.; Yu, I.; Hernandez, N.; Fang, K.; Zhang, W.; Li, J.; Munui, K. N.; Sot, R.; Luong, K.; Bonzo, R.; Sankar, R.; Chiu, D.; Rodriguez, V. A.

    2016-12-01

    The recent health crisis in Flint, Michigan has attracted an amount of interest in other public utilities' water supplies and infrastructure with regards to concerns over the presence of lead. In an effort to begin assessing the potential for a health crisis similar to that experienced in Flynt, during 2016 our team measured lead concentration levels in water samples by collected in Alameda County. More than 12 sites were selected from which samples were collected. These sites included parks, schools, and private residences. At each site 500mL samples were collected and prepared for later analysis. Samples were subjected to an analytical chemistry technique designed to isolate and concentrate lead to detectable levels of 1 part per billion (ppb). All 8 samples yielded detectable levels of lead; all samples were also well below the EPA regulatory 15 ppb. Two samples collected in West Oakland parks were found to have the highest and lowest levels: DeFremery (4 ppb) and Raimondi (1ppb), respectively. Though preliminary in nature, results from this study suggest that further investigations should be undertaken to assess possible lead contamination associated with drinking water sources in Alameda County.

  19. Lead and cadmium concentrations in seawater and algae of the Tunisian coast.

    Science.gov (United States)

    El Ati-Hellal, M; Hedhili, A; Hellal, F; Boujlel, K; Dachraoui, M; Bousnina, M; Ghorbel, H; Ndhif, M

    2005-01-01

    Both lead and cadmium are toxic trace metals, even in very weak concentrations. The aim of this study was to estimate lead and cadmium pollution in various sites of the Tunisian coast and to verify the possibility of modification of the algae bioconcentration power according to water physico-chemical conditions. Our study concerned 99 samples of algae and 99 samples of seawater, taken in different sites of the Tunisian littoral. The analysis was realized by atomic absorption spectrophotometry (oven graphite). In algae, Sfax site presented the highest concentrations of lead when Sousse site showed the lowest ones. In seawater, the most amounts of lead were observed in Bizerte, Mahdia and Sfax sites, and those of cadmium in Bizerte and Medenine coasts. Bizerte's coast seems to be the most exposed zone to pollution. Indeed, the intensification of sea traffic may take place on this pollution because hydrocarbons derived from petroleum contain some tetraethylic lead characterised by its great toxicity. Sousse's region is the least polluted zone; it might be due to the development of tourism and a strict regulation of pollution in this district.

  20. Unique pattern of molt leads to low intraindividual variation in feather mercury concentrations in penguins.

    Science.gov (United States)

    Brasso, Rebecka L; Drummond, Bridgette E; Borrett, Stuart R; Chiaradia, André; Polito, Michael J; Rey, Andrea Raya

    2013-10-01

    The authors hypothesized that the catastrophic annual molt of penguins (Sphenisciformes) would lead to reduced intraindividual variation of mercury concentrations in body feathers. While mean mercury concentrations varied significantly among 8 penguin species, intraindividual variability did not differ among species and was 3 times lower than values observed in other seabirds. The findings of the present study suggest that a single body feather collected at random per individual can be adequate to estimate mercury exposure at the population level in penguins. © 2013 SETAC.

  1. Effect of polysulfone concentration on the performance of membrane-assisted lead acid battery

    Directory of Open Access Journals (Sweden)

    Ahmad Fauzi Ismail

    2002-11-01

    Full Text Available The application of lead acid battery in tropical countries normally faces the problem of water decomposition. This phenomenon is due to the factor of charge-discharge reaction in the battery and heat accumulation caused by hot tropical climate and heat generated from engine compartment. The objective of this study is to analyze the effect of polysulfone concentration on the performance of membrane-assisted lead-acid battery. Gas separation membranes, prepared through wet-dry phase inversion method and using various polysulfone concentrated formulations, were applied on the battery vent holes, for the purpose of preventing electrolyte from evaporating to the atmosphere. The best membrane, which retains the most electrolyte, will be chosen to be applied on the soon-to-be-developed “membrane-assisted maintenance- free battery”. This maintenance-free battery will need no topping up of deionized water every time the electrolyte level goes low.

  2. Insights into past atmospheric lead emissions using lead concentrations and isotopic compositions in historic lichens and fungi (1852-2008) from central and southern Victoria, Australia

    Science.gov (United States)

    Wu, Liqin; Taylor, Mark Patrick; Handley, Heather K.; Gulson, Brian L.

    2016-08-01

    Lead concentrations and lead isotopic compositions were determined in historic central and southern Victoria, Australia lichen (Cladonia and Usnea) and fungi (Trametes) samples collected between 1852 and 2008 to evaluate long-term atmospheric lead contamination sources. The data are grouped into four time intervals of 1850-1931, 1932-1984, 1985-2001 and 2002-2008 corresponding to the history of leaded petrol use in Australia. Elevated lichen and fungi lead concentrations and relatively high isotopic compositions from the period 1850-1931 are attributed to lithogenic sources, gold mining activities and early industrialisation. Significant increases in lichen and fungi lead concentrations and concomitant lower lead isotopic compositions correspond to the marked increase in lead emissions from leaded petrol use after 1932. Following the end of leaded petrol use in 2002 lead isotopic composition values 'recover' toward more lithogenic values. However, the lead isotopic composition data indicate that the environmental impact from leaded petrol emissions persists in contemporary samples dated to 2002-2008. Overall, the data reveal that herbarium lichens and fungi from central and southern Victoria can be used as proxies for environmental lead emissions over the past 150 years.

  3. The Effect of Acceptor and Donor Doping on Oxygen Vacancy Concentrations in Lead Zirconate Titanate (PZT

    Directory of Open Access Journals (Sweden)

    Christoph Slouka

    2016-11-01

    Full Text Available The different properties of acceptor-doped (hard and donor-doped (soft lead zirconate titanate (PZT ceramics are often attributed to different amounts of oxygen vacancies introduced by the dopant. Acceptor doping is believed to cause high oxygen vacancy concentrations, while donors are expected to strongly suppress their amount. In this study, La3+ donor-doped, Fe3+ acceptor-doped and La3+/Fe3+-co-doped PZT samples were investigated by oxygen tracer exchange and electrochemical impedance spectroscopy in order to analyse the effect of doping on oxygen vacancy concentrations. Relative changes in the tracer diffusion coefficients for different doping and quantitative relations between defect concentrations allowed estimates of oxygen vacancy concentrations. Donor doping does not completely suppress the formation of oxygen vacancies; rather, it concentrates them in the grain boundary region. Acceptor doping enhances the amount of oxygen vacancies but estimates suggest that bulk concentrations are still in the ppm range, even for 1% acceptor doping. Trapped holes might thus considerably contribute to the charge balancing of the acceptor dopants. This could also be of relevance in understanding the properties of hard and soft PZT.

  4. The Effect of Acceptor and Donor Doping on Oxygen Vacancy Concentrations in Lead Zirconate Titanate (PZT)

    Science.gov (United States)

    Slouka, Christoph; Kainz, Theresa; Navickas, Edvinas; Walch, Gregor; Hutter, Herbert; Reichmann, Klaus; Fleig, Jürgen

    2016-01-01

    The different properties of acceptor-doped (hard) and donor-doped (soft) lead zirconate titanate (PZT) ceramics are often attributed to different amounts of oxygen vacancies introduced by the dopant. Acceptor doping is believed to cause high oxygen vacancy concentrations, while donors are expected to strongly suppress their amount. In this study, La3+ donor-doped, Fe3+ acceptor-doped and La3+/Fe3+-co-doped PZT samples were investigated by oxygen tracer exchange and electrochemical impedance spectroscopy in order to analyse the effect of doping on oxygen vacancy concentrations. Relative changes in the tracer diffusion coefficients for different doping and quantitative relations between defect concentrations allowed estimates of oxygen vacancy concentrations. Donor doping does not completely suppress the formation of oxygen vacancies; rather, it concentrates them in the grain boundary region. Acceptor doping enhances the amount of oxygen vacancies but estimates suggest that bulk concentrations are still in the ppm range, even for 1% acceptor doping. Trapped holes might thus considerably contribute to the charge balancing of the acceptor dopants. This could also be of relevance in understanding the properties of hard and soft PZT. PMID:28774067

  5. Spatial distribution of lead concentrations in urban surface soils of New Orleans, Louisiana USA.

    Science.gov (United States)

    Abel, Michael T; Suedel, Burton; Presley, Steven M; Rainwater, Thomas R; Austin, Galen P; Cox, Stephen B; McDaniel, Les N; Rigdon, Richard; Goebel, Timothy; Zartman, Richard; Leftwich, Blair D; Anderson, Todd A; Kendall, Ronald J; Cobb, George P

    2010-10-01

    Immediately following hurricane Katrina concern was raised over the environmental impact of floodwaters on the city of New Orleans, especially in regard to human health. Several studies were conducted to determine the actual contaminant distribution throughout the city and surrounding wetlands by analyzing soil, sediment, and water for a variety of contaminants including organics, inorganics, and biologics. Preliminary investigations by The Institute of Environmental and Human Health at Texas Tech University concluded that soils and sediments contained pesticides, semi-volatiles, and metals, specifically arsenic, iron, and lead, at concentrations that could pose a significant risk to human health. Additional studies on New Orleans floodwaters revealed similar constituents as well as compounds commonly found in gasoline. More recently, it has been revealed that lead (Pb), arsenic, and vanadium are found intermittently throughout the city at concentrations greater than the human health soil screening levels (HHSSLs) of 400, 22 (non-cancer endpoint) and 390 μg/g, respectively. Of these, Pb appears to present the greatest exposure hazard to humans as a result of its extensive distribution in city soils. In this study, we spatially evaluated Pb concentrations across greater New Orleans surface soils. We established 128 sampling sites throughout New Orleans at approximately half-mile intervals. A soil sample was collected at each site and analyzed for Pb by ICP-AES. Soils from 19 (15%) of the sites had Pb concentrations exceeding the HHSSL threshold of 400 μg/g. It was determined that the highest concentrations of Pb were found in the south and west portions of the city. Pb concentrations found throughout New Orleans in this study were then incorporated into a geographic information system to create a spatial distribution model that can be further used to predict Pb exposure to humans in the city.

  6. Preliminary indications of blood lead concentrations, among occupationally exposed and non exposed Palestinians

    Directory of Open Access Journals (Sweden)

    Mutaz A. Al-Qutob

    2012-08-01

    Full Text Available Despite the lower rate of exposure to leaded compounds in the past ten years, due to reducedlead petrol concentrations in the ambient air and improvement in environmental control measures, leadpoisoning is still an occupational and environmental disease of great concern in public health. Thepresence of other sources of lead exposure after the ban of leaded gasoline could be a risk factor forelevated blood lead concentrations. In this study blood lead levels (BLL were screened in bothoccupationally and non-occupationally exposed groups in the Palestinian Territories by inductive coupledplasma-mass spectrometry (Agilent 7500 ICP-MS. The non-occupationally exposed groups included 18normal healthy smoker males, 18 non smoker males, and 18 females. Occupationally exposed groupsinclude 25 workers in the assaying and refining of gold and 19 workers in auto-repair garages. Data wasanalyzed using the statistical computer package (SPSS. Mean blood lead levels of all groups were belowthe action level according to Centers for Disease Control (CDC and Occupational Safety and HealthAdministration (OSHA (<10 μg/dL. No statistical significant differences were found between workersgroup and control groups. In the control group, a paired t-test showed a statistically significant difference(p<0.05 between the female group and smoker male group. There was no correlation with age for allgroups except the female group and auto-repair workers which showed significant correlation (p<0.05with both age and years of work. This could be contributed to differences in genetic make-up, chemicalexposure history and age related decreased function of the detoxification processes. Since mean BLL(3.66 μg/dL of the control group was comparable to economically advantaged countries like USA (1.6μg/dL and those with low mean of (1.96 μg/dL like Jordan, lead is not considered a majorenvironmental pollutant in Palestine and the screening is recommended only at the workers in

  7. Effective radium concentration in topsoils contaminated by lead and zinc smelters

    Energy Technology Data Exchange (ETDEWEB)

    Girault, Frédéric, E-mail: girault@ipgp.fr [Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, CNRS, Paris, France. (France); Perrier, Frédéric; Poitou, Charles; Isambert, Aude [Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, CNRS, Paris, France. (France); Théveniaut, Hervé; Laperche, Valérie [Bureau de Recherches Géologiques et Minières, Orléans, France. (France); Clozel-Leloup, Blandine [Bureau de Recherches Géologiques et Minières, Villeurbanne, France. (France); Douay, Francis [Laboratoire Génie Civil et géo Environnement, ISA Lille, Lille, France. (France)

    2016-10-01

    Trace elements (TE) are indicative of industrial pollution in soils, but geochemical methods are difficult to implement in contaminated sites with large numbers of samples. Therefore, measurement of soil magnetic susceptibility (MS) has been used to map TE pollutions, albeit with contrasted results in some cases. Effective radium concentration (EC{sub Ra}), product of radium concentration by the emanation factor, can be measured in a cost-effective manner in the laboratory, and could then provide a useful addition. We evaluate this possibility using 186 topsoils sampled over about 783 km{sup 2} around two former lead and zinc smelters in Northern France. The EC{sub Ra} values, obtained from 319 measurements, range from 0.70 ± 0.06 to 12.53 ± 0.49 Bq·kg{sup −1}, and are remarkably organized spatially, away from the smelters, in domains corresponding to geographical units. Lead-contaminated soils, with lead concentrations above 100 mg·kg{sup −1} < 3 km from the smelters, are characterized on average by larger peak EC{sub Ra} values and larger dispersion. At large scales, away from the smelters, spatial variations of EC{sub Ra} correlate well with spatial variations of MS, thus suggesting that, at distance larger than 5 km, variability of MS contains a significant natural component. Larger EC{sub Ra} values are correlated with larger fine fraction and, possibly, mercury concentration. While MS is enhanced in the vicinity of the smelters and is associated with the presence of soft ferrimagnetic minerals such as magnetite, it does not correlate systematically with metal concentrations. When multiple industrial and urban sources are present, EC{sub Ra} mapping, thus, can help in identifying at least part of the natural spatial variability of MS. More generally, this study shows that EC{sub Ra} mapping provides an independent and reliable assessment of the background spatial structure which underlies the structure of a given contamination. Furthermore, EC{sub Ra

  8. Correlation Between Surface Area and Dissolving Properties of Lead - A Step in the Investigation of Higher than Standard Lead Concentration in Drinking Water in Washington, D.C.

    Science.gov (United States)

    Hua, M.; Garduno, L.; Mondragon, J. D.; Cuff, K. E.

    2004-12-01

    Several recently published articles by the Washington Post exposing the alarming concentration of lead in drinking water from schools and homes in the Washington D.C. area sparked our interest in the correlation between lead-containing materials used in plumbing and rate of lead solubility. Elementary children who attend schools in various regions of the District were contacted by San Francisco Bay Area- based high school students who are participants in the NSF-sponsored Environmental Science Information Technology Activities (ESITA) project. After receiving a thorough explanation of required sampling procedures, the elementary school children sent 500 ml water samples from their homes and schools to Berkeley along with information on the locations from which the water samples were collected. These water samples were analyzed for lead content at the Environmental Science Research Program laboratory at Lawrence Hall of Science. The majority of the samples contained more than 15 ppb of lead, which is the EPA action level. We hypothesize that there are three possible sources of lead in the drinking water: 1) lead pipes in the water main; 2) lead pipes in the service main; and 3) lead soldering that was often previously used to connect piping. We chose to investigate the effect of lead-based solder on the overall lead concentration in water. Using a soldering iron, we melted lead solder to create discs ranging from one to five centimeter diameter and one to thirty-six grams of mass. These discs were then placed into a beaker with 500 ml of 7.1pH distilled water and allowed to stand for 48 hours. At the end of 48 hours, the water samples were prepared for analysis using the EPA approved lead-dithizone procedure. Results showed an exponential relationship between disc surface area and the concentration of dissolved lead measured in the sample. Therefore, lead-based solder can represent a possible major source of lead contamination.

  9. Evidence for Variable, Correlated X-ray and Optical/IR Extinction toward the Nearby, Pre-main Sequence Binary TWA 30

    CERN Document Server

    Principe, David A; Kastner, Joel H; Stelzer, Beate; Alcala, Juan

    2016-01-01

    We present contemporaneous XMM-Newton X-ray and ground-based optical/near-IR spectroscopic observations of the nearby ($D \\approx 42$ pc), low-mass (mid-M) binary system TWA 30A and 30B. The components of this wide (separation $\\sim$3400 AU) binary are notable for their nearly edge-on disk viewing geometries, high levels of variability, and evidence for collimated stellar outflows. We obtained XMM-Newton X-ray observations of TWA 30A and 30B in 2011 June and July, accompanied (respectively) by IRTF SpeX (near-IR) and VLT XSHOOTER (visible/near-IR) spectroscopy obtained within $\\sim$20 hours of the X-ray observations. TWA 30A was detected in both XMM-Newton observations at relatively faint intrinsic X-ray luminosities ($L_{X}$$\\sim$$8\\times10^{27}$ $erg$ $s^{-1}$) compared to stars of similar mass and age . The intrinsic (0.15-2.0 keV) X-ray luminosities measured in 2011 had decreased by a factor 20-100 relative to a 1990 (ROSAT) X-ray detection. TWA 30B was not detected, and we infer an upper limit of ($L_{X}...

  10. Critical scattering of synchrotron radiation in lead zirconate-titanate with low titanium concentrations

    Science.gov (United States)

    Andronikova, D. A.; Bosak, A. A.; Bronwald, Iu. A.; Burkovsky, R. G.; Vakhrushev, S. B.; Leontiev, N. G.; Leontiev, I. N.; Tagantsev, A. K.; Filimonov, A. V.; Chernyshov, D. Yu.

    2015-12-01

    Diffuse scattering in the lead zirconate-titanate single crystal with a titanium concentration of 0.7 at % has been studied by the synchrotron radiation scattering method. Measurements have been performed both in the vicinity of the Brillouin zone center and at the M-point. Highly anisotropic diffuse scattering has been revealed in the paraelectric phase near the Brillouin zone center; diffuse scattering anisotropy is similar to that previously observed in pure lead zirconate. The temperature dependence of this diffuse scattering obeys a critical law with T c ≈ 480 K. Diffuse scattering in the vicinity of the M-point weakly depends on temperature; this dependence behaves differently at M-points with various indices.

  11. On the potential contribution of open lead particle emissions to the central Arctic aerosol concentration

    Directory of Open Access Journals (Sweden)

    A. Held

    2010-10-01

    Full Text Available During the ice-breaker borne ASCOS expedition (Arctic Summer Cloud Ocean Study direct eddy covariance measurements of aerosol number fluxes were carried out in August 2008 on the edge of an ice floe drifting in the central Arctic Ocean between 2°–10° W longitude and 87°–87.5° N latitude. The median aerosol transfer velocities over different surface types (open water leads, ice ridges, snow and ice surfaces ranged from 0.27 to 0.68 mm s−1 during deposition-dominated episodes. Emission periods were observed more frequently over the open lead, while the snow behaved primarily as a deposition surface. Directly measured aerosol fluxes were compared with particle deposition parameterizations in order to estimate the emission flux from the observed net aerosol flux. Finally, the contribution of the open lead particle source to atmospheric variations in particle number concentration was evaluated and compared with the observed temporal evolution of particle number. The direct emission of aerosol particles from the open lead can only explain 5–10% of the observed particle number variation in the mixing layer close to the surface.

  12. DDE, PCBs, cadmium, lead, and mercury concentrations in rhinoceros auklets from Washington

    Science.gov (United States)

    Blus, L.J.; Fitzner, R.E.; Leschner, L.L.; Wilson, U.W.

    1999-01-01

    In July 1981, 5 adult rhinoceros auklets (Cerorhinca monocerata) were captured on the ground near nesting areas on each of Protection and Destruction Islands, Washington. The birds were euthanized, and their livers and kidneys removed and analyzed. Levels (I?g / g wet weight) of DDE (0.11 to 0.95), polychlorinated biphenyls (no residue detected [ND] to 1.1), mercury (0.60 to 1.8), and lead (ND to 0.85) in livers and cadmium (9.1 to 21.9) in kidneys were similar in each colony. All concentrations were less than known effect levels.

  13. Blood lead concentrations in Alaskan tundra swans: linking breeding and wintering areas with satellite telemetry

    Science.gov (United States)

    Ely, Craig R.; Franson, Christian

    2014-01-01

    Tundra swans (Cygnus columbianus) like many waterfowl species are susceptible to lead (Pb) poisoning, and Pb-induced mortality has been reported from many areas of their wintering range. Little is known however about Pb levels throughout the annual cycle of tundra swans, especially during summer when birds are on remote northern breeding areas where they are less likely to be exposed to anthropogenic sources of Pb. Our objective was to document summer Pb levels in tundra swans throughout their breeding range in Alaska to determine if there were population-specific differences in blood Pb concentrations that might pose a threat to swans and to humans that may consume them. We measured blood Pb concentrations in tundra swans at five locations in Alaska, representing birds that winter in both the Pacific Flyway and Atlantic Flyway. We also marked swans at each location with satellite transmitters and coded neck bands, to identify staging and wintering sites and determine if winter site use correlated with summer Pb concentrations. Blood Pb levels were generally low ( Blood Pb levels varied significantly across the five breeding areas, with highest concentrations in birds on the North Slope of Alaska (wintering in the Atlantic Flyway), and lowest in birds from the lower Alaska Peninsula that rarely migrate south for winter.

  14. Lead

    Science.gov (United States)

    ... Chapter 6 Chapter 7 Chapter 8 Chapter 9 Appendix I Appendix II Tables Figures State Programs Alabama Alaska Arizona ... Tool Kit Resources Healthy Homes and Lead Poisoning Prevention Training Center (HHLPPTC) Training Tracks File Formats Help: ...

  15. Evidence for variable, correlated X-ray and optical/IR extinction towards the nearby, pre-main-sequence binary TWA 30

    Science.gov (United States)

    Principe, David A.; Sacco, G.; Kastner, J. H.; Stelzer, B.; Alcalá, J. M.

    2016-06-01

    We present contemporaneous XMM-Newton X-ray and ground-based optical/near-IR spectroscopic observations of the nearby (D ≈ 42 pc), low-mass (mid-M) binary system TWA 30A and 30B. The components of this wide (separation ˜3400 au) binary are notable for their nearly edge-on disc viewing geometries, high levels of variability, and evidence for collimated stellar outflows. We obtained XMM-Newton X-ray observations of TWA 30A and 30B in 2011 June and July, accompanied (respectively) by Infrared Telescope Facility SpeX (near-IR) and VLT XSHOOTER (visible/near-IR) spectroscopy obtained within ˜20 h of the X-ray observations. TWA 30A was detected in both XMM-Newton observations at relatively faint intrinsic X-ray luminosities (LX ˜ 8 × 1027 erg s-1) compared to stars of similar mass and age. The intrinsic (0.15-2.0 keV) X-ray luminosities measured in 2011 had decreased by a factor 20-100 relative to a 1990 (ROSAT) X-ray detection. TWA 30B was not detected, and we infer an upper limit on its X-ray Luminosity of LX ≲ 3.0 × 1027 erg s-1. We measured a decrease in visual extinction towards TWA 30A (from AV ≈ 14.9 to AV ≈ 4.7) between the two 2011 observing epochs, and we find evidence for a corresponding significant decrease in X-ray absorbing column (NH). The apparent correlated change in AV and NH is suggestive of variable obscuration of the stellar photosphere by disc material composed of both gas and dust. However, in both observations, the inferred NH to AV ratio is lower than that typical of the interstellar medium, suggesting that the disc is either depleted of gas or is deficient in metals in the gas phase.

  16. Urgent percutaneous coronary intervention leads to a decrease in serum concentrations of soluble CD40 ligand

    Directory of Open Access Journals (Sweden)

    Ratković Nenad

    2010-01-01

    Full Text Available Background/Aim. Inflammation as a consequence of vascular injury after percutaneous coronary intervention (PCI is a pathological substrate of restenosis and of its complications. The aim of the study was to examine perprocedural inflammatory response expressed by soluble CD40 ligand (sCD40L and C-reactive protein (CRP in patients treated with PCI and dual antiplatelet therapy. Methods. The experimental group included 52 patients (80.8% men, age 60 ± 9 years with angina pectoris treated by PCI (22 urgent PCI with stent implantation, and dual antiplatelet therapy (tienopiridins and aspirin, according to the current recommendations for the execution of the intervention. The control group consisted of 8 patients (70.5% men, age 59 ± 7 years with angina pectoris, who had undergone coronarography taking aspirin 3 days prior to it. In all the patients 24 hours before and after the PCI concentrations of CRP and sCD40L in the blood were determined. Results. In the experimental group, the concentration of sCD40L was lower as compared to the control (p < 0.02. In 34 (65% patients postprocedural decrease in sCD40L was recorded, in 18 (34.6% of them increase, while in 50 (96% patients there was a rise in CRP. The patients with postprocedural fall in sCD40L hod greater preprocedural concentration of sCD40L (p < 0.001, and less postprocedural concentration of sCD40L (p < 0.001, compared to the group with an increase in sCD40L after the PCI, while CRP levels tients treated with emergency PCI compared to elective patietns had a postprocedural decrease in sCD40L (p = 0.02. Increase in the level of CRP was higher in the group with emergency PCI in relation to elective PCI (p < 0.01. Conclusion. Emergency PCI procedures in the treatment of patients with unstable angina pectoris lead to a postprocedural fall in the serum concentration of sCD40L. Dual antiplate therapy with tienopiridins and aspirin inhibits the release of sCD40L. Regardless a clinical presentation

  17. Regional and long-term patterns of lead concentrations in fluvial, marine and terrestrial systems and humans in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Hagner, C. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Hydrophysik

    2000-07-01

    Lead contamination of abiotic and biotic systems has been studied closely since the early 1970s, when lead was firstly perceived as an environmental problem. Lead emission reduction policies were implemented throughout Europe during that time. Nonetheless, analyses of lead loads in aquatic systems, such as the river Elbe, showed no decline over time in either suspended matter or surface sediments. Regional differences in lead concentrations of fluvial systems were found, due to tidal influence, runoff and local emissions. Lead contamination of sediments from the North Sea was highest in estuaries. Concentrations in sediment cores were quite stable down to the depth of background values, due to bioturbation, flow, waves and meandering channels. Terrestrial soils in Europe were highly polluted in industrial and ore mining areas and large cities. No decline in lead concentrations was evident in foraminifers, bladder wrack or fish. It was found that contamination in sediments, mammals and fish was higher in coastal zones than in the open sea. In contrast to in aquatic organisms, positive impacts of lead reduction regulations were detected in terrestrial plants, which adsorbed or took up lead mainly through atmospheric lead deposition. European lead concentrations in plants decreased coincidently with lead emissions. That trend could also be identified in the blood lead levels of the human population in Europe: since 1979 they have declined in every group of the population. Mainly influenced by age, sex and the living environment, overall, the lead loads of humans had never been high enough to cause health danger. (orig.)

  18. Biosynthesis of lead nanoparticles by the aquatic water fern, Salvinia minima Baker, when exposed to high lead concentration.

    Science.gov (United States)

    Castro-Longoria, E; Trejo-Guillén, K; Vilchis-Nestor, A R; Avalos-Borja, M; Andrade-Canto, S B; Leal-Alvarado, D A; Santamaría, J M

    2014-02-01

    Salvinia minima Baker is a small floating aquatic fern that is efficient for the removal and storage of heavy metals such as lead and cadmium. In this study, we report that lead removal by S. minima causes large accumulation of lead inside the cells in the form of nanoparticles (PbNPs). The accumulation pattern of lead was analyzed in both, submerged root-like modified fronds (here named "roots"), and in its aerial leaf-like fronds ("leaves"). Analysis by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) confirmed the biosynthesis of PbNPs by the plant. In both, roots and leaves, PbNPs were found to accumulate almost exclusively at the cell wall and closely associated to the cell membrane. Two types of PbNPs shapes were found in cells of both tissues, those associated to the cell wall were quasi-spherical with 17.2±4.2 nm of diameter, while those associated to the cell membrane/cytoplasm were elongated. Elongated particles were 53.7±29.6 nm in length and 11.1±2.4 nm wide. Infrared spectroscopy (IR) results indicate that cellulose, lignin and pectin are the major components that may be acting as the reducing agents for lead ions; these findings strongly suggest the potential use of this fern to further explore the bio-assisted synthesis of heavy metal nanostructures.

  19. The Feasibility of Using Lead in Hair Concentration in Monitoring Environmental Exposure in Children

    NARCIS (Netherlands)

    Wibowo, A.A.E.; Brunekreef, B.; Lebret, E.; Pieters, H.

    1980-01-01

    The feasibility of lead in hair as an indicator of lead exposure has been compared to that of lead in blood and zinc protoporphyrin in blood levels in 1-3 year-old children living within 1 km of a lead smelter. Lead exposure was measured as lead in house dust, outdoor and indoor lead in air

  20. EDXS and XRD Analyses of Coleus with Different Concentration Selenium Supplements Under Lead Stress

    Directory of Open Access Journals (Sweden)

    QIN Hui-yuan

    2014-04-01

    Full Text Available In order to study the changes of the morphologies and element composition in Coleus hlumei Benth(Coleusroots and leaves under1.0 mmol·L-1 Pb2+ stress with selenium ( Setreatments, and to preliminarily investigate the relief mechanism of Se level on lead toxicity from the perspective of spectroscopy, Coleus was cultivated in nutrient solutions with different concentrations of Se. The results showed that the content of C, K and Ca elements in roots decreased, while 0, Mg, Al, Si, Fe and Pb elements increased under Pb stress with Se treatments. In addi-tion, the content of C, Mg, Al, Si, K, Ca and Fe elements in leaves decreased, while 0 and Cl elements increased. The element species and its contents in roots were changed obviously under Pb stress with Se treatments, and crystalline solid and crystal phase in roots were correspond-ingly changed.

  1. Utilization of polysaccharides as depressants for the flotation separation of copper/lead concentrate

    Institute of Scientific and Technical Information of China (English)

    Qin Wenqing; Wei Qian; Jiao Fen; Yang Congren; Liu Ruizeng; Wang Peipei; Ke Lifang

    2013-01-01

    The interaction mechanism between dextrin and minerals has been investigated through micro-flotation,adsorption density measurements,Fourier transform infrared ray (FTIR) spectroscopic studies and dissolution tests.Dextrin shows a good depressing action towards galena but not chaicopyrite.FTIR spectroscopic studies indicate that dextrin chemically adsorbed on galena surface in alkaline pH range.Dissolution tests confirm leaching action of metal ions from chalcopytite and galena surfaces,and dextrin-lead ion interaction.Adsorption measurements present that the higher adsorption density of O-isopropyl-N-ethyl thionocarbamate (IPETC) onto chalcopyrite than that onto galena,and IPETC adsorbed on galena decrease with increasing dextrin concentrations in the presence of dextrin,attesting the flotation results.

  2. An integrated temperature-compensated flexible shear-stress sensor microarray with concentrated leading-wire.

    Science.gov (United States)

    Tang, Jian; Liu, Wu; Zhang, Weiping; Sun, Yongming; Chen, Honghai

    2016-02-01

    Flexible shear stress sensor is quite important for characterizing curved surface flows. In this work, a novel integrated shear stress sensor microarray is designed with twenty parallel channels, which share the concentrated leading-wire to transmit the ground signal. Electrical pads in rows are easily connected to the circuits with two separate Wheatstone bridges and constant-temperature-difference mode operation is provided for the hot-wires. Temperature crosstalk between adjacent hot-wires is prevented well and the effectiveness of the temperature compensated circuits is verified. Relatively large output response is obtained as the shear stress varies and the sensitivity of the sensors is measured about 0.086 V(2)/Pa(1/3) with nonlinearity lower than 1%, revealing high performance characteristic of the sensors.

  3. Measuring the mass of a pre-main sequence binary star through the orbit of TWA5A

    Energy Technology Data Exchange (ETDEWEB)

    Konopacky, Q; Ghez, A; Duchene, G; McCabe, C; Macintosh, B

    2007-01-18

    We present the results of a five year monitoring campaign of the close binary TWA 5Aab in the TW Hydrae association, using speckle and adaptive optics on the W.M. Keck 10 m telescopes. These measurements were taken as part of our ongoing monitoring of pre-main sequence (PMS) binaries in an effort to increase the number of dynamically determined PMS masses and thereby calibrate the theoretical PMS evolutionary tracks. Our observations have allowed us to obtain the first determination of this system's astrometric orbit. We find an orbital period of 5.94 {+-} 0.09 years and a semi-major axis of 0.''066 {+-} 0.''005. Combining these results with a kinematic distance, we calculate a total mass of 0.71 {+-} 0.14 M{sub {circle_dot}} (D/44 pc){sup 3}. for this system. This mass measurement, as well as the estimated age of this system, are consistent to within 2{sigma} of all theoretical models considered. In this analysis, we properly account for correlated uncertainties, and show that while these correlations are generally ignored, they increase the formal uncertainties by up to a factor of five and therefore are important to incorporate. With only a few more years of observation, this type of measurement will allow the theoretical models to be distinguished.

  4. Lead concentration and isotope chronology in two coastal environments in Western and South East Asia

    Science.gov (United States)

    Carrasco, G. G.; Chen, M.; Boyle, E. A.; Zhao, N.; Nurhati, I. S.; Gevao, B.; al Ghadban, A.; Switzer, A.; Lee, J. M.

    2014-12-01

    Lead is a trace metal that is closely related to anthropogenic activity, mainly via leaded gasoline and coal combustion. The study of lead concentrations and isotopes in seawater, sediments, corals and aerosols allows for a systematic look at its sources and their time evolution in a natural environment. We will discuss results from two projects in Western and South East Asia, regions that have seen dramatic socio-economical changes over the past half-century that may have left environmental signals. These results highlight the usefulness of the method, indicate the degree of complexity of these systems, and point to the need for a continuous monitoring of anthropogenic trace metals in the small-medium coastal scale to be able to asses the larger scale effects of human activity. On the one hand, coastal Kuwait is heavily influenced by the Shat al-Arab river and shows a clear anthropogenic signature from Kuwait city. A mix of two sources can be tracked through the coral and sediment chronological records, with Pb206/Pb207 ratios (1.202 and 1.151) that approach the suspected source values (1.21 and 1.12) and eliminate the possibility of other sources. Through a wide sediment geographic distribution, the strength of the anthropogenic signature is modulated. On the other hand, Singapore offers a more complex system, where an apparent mix of two sources (extreme isotope ratios 1.215 and ~1.14) occurs also, but where either an unresolved potentially important third source (isotope ratio ~1.18), or an isotope exchange process should be invoked. The sediment and coral records allows us to track the changes through time; however, there seems to be incongruence with the aerosol isotope record. Further potential sources are being explored currently and will be discussed.

  5. Lead concentrations and isotope ratios in street dust determined by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Nageotte, S M; Day, J P

    1998-01-01

    A major source of environmental lead, particularly in urban areas, has been from the combustion of leaded petrol. Street dust has previously been used to assess urban lead contamination, and the dust itself can also be a potential source of lead ingestion, particularly to children. The progressive reduction of lead in petrol, in recent years, would be expected to have been reflected in a reduction of lead in urban dust. We have tested this hypothesis by repeating an earlier survey of Manchester street dust and carrying out a comparable survey in Paris. Samples were collected from streets and parks, lead was extracted by digestion with concentrated nitric acid and determined by electrothermal atomic absorption spectrometry. Lead isotope ratios were measured by inductively coupled plasma mass spectrometry. Results for Manchester show that lead concentrations have fallen by about 40% (street dust averages, 941 micrograms g-1 (ppm) in 1975 down to 569 ppm in 1997). In Paris, the lead levels in street dust are much higher and significant differences were observed between types of street (not seen in Manchester). Additionally, lead levels in parks were much lower than in Manchester. Samples collected under the Eiffel Tower had very high concentrations and lead isotope ratios showed that this was unlikely to be fallout from motor vehicles but could be due to the paint used on the tower. Isotope ratios measurements also revealed that lead additives used in France and the UK come from different sources.

  6. Surface air concentration and deposition of lead-210 in French Guiana: two years of continuous monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Melieres, Marie-Antoinette E-mail: melieres@glaciog.ujf-grenoble.fr; Pourchet, Michel; Richard, Sandrine

    2003-07-01

    To make up for the lack of data on {sup 210}Pb aerosol deposition in tropical regions and to use this radionuclide as an aerosol tracer,a monitoring station was run for two years at Petit-Saut, French Guiana. Lead-210 concentration in air at ground level was monitored continuously together with atmospheric total deposition. The air concentration has a mean value of 0.23{+-}0.02 mBq m{sup -3} during both wet and dry seasons, and it is only weakly affected by the precipitation mechanism. This result was unexpected in a wet tropical region, with a high precipitation rate. In contrast, deposition clearly correlates with precipitation for low/moderate rainfall (<15 cm per 15-day), while this correlation is masked by strong fluctuations at high rainfall. The estimated mean annual deposition over the last ten years is 163{+-}75 Bq m{sup -2} y{sup -1}. This provides a procedure fo estimating this mean flux at other sites in French Guiana.

  7. Effect of Alginate Concentration on Alginate-TiO{sub 2} Hydrogel for Lead Ion Removal

    Energy Technology Data Exchange (ETDEWEB)

    Teoh, W T; Sato, K [Department of Environmental Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka 940-2188 (Japan); Saito, N, E-mail: teoh@vos.nagaokaut.ac.jp [Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka 940-2188 (Japan)

    2011-03-15

    Alginate-TiO{sub 2} hydrogel was investigated for lead ion (Pb(II)) removal. By immobilizing TiO{sub 2} powder onto an alginate biopolymer, it is possible to utilize the ion exchange properties of the alginate and the photoreducibility of TiO{sub 2} to recover Pb(II). However, these photocatalytic activities degrade the alginate biopolymer in addition to removing Pb(II). This study examines photolytic degradation of alginate-TiO{sub 2} hydrogels prepared with alginate concentrations of 1, 1.5, 2, and 2.5%w/v; the same amount (0.4%w/v) of TiO{sub 2} was added to each alginate solution. The alginate-TiO{sub 2} hydrogels were formed by dripping the alginate-TiO{sub 2} suspension into a 0.2 M calcium chloride solution. The samples were washed and dried and then photoirradiated. The samples with alginate concentrations of 1 and 1.5%w/v were depolymerized, whereas the surface morphology of the sample that prepared from the 2%w/v alginate solution remained unchanged. The samples prepared from 1.5, 2, and 2.5%w/v alginate solutions had Pb(II) uptakes of 24.0, 39.8, and 39.7 mg/g, respectively.

  8. The relationship between bone health and plasma zinc, copper lead and cadmium concentration in osteoporotic women.

    Science.gov (United States)

    Sadeghi, Naficeh; Oveisi, Mohammad Reza; Jannat, Behrooz; Hajimahmoodi, Mannan; Behzad, Masoomeh; Behfar, Abdolazim; Sadeghi, Fatemeh; Saadatmand, Sahereh

    2014-01-01

    Osteoporosis is a multi factorial disease with dimension of genetic and nutritional considerations. The aim of this study was to present data from the association of plasma zinc, copper and toxic elements of lead and cadmium levels with bone mineral density in Iranian women. 135 women gave their information and enrolled. Fasting plasma was used for measurement of trace elements and heavy metals by Differential Pulse Anodic Stripping Voltammetry. Control group (n = 51) were normal in both lumbar spine (L1-L4) and femoral neck density (T-score ≥ -1), but just femoral neck T-score was considered as criterion in selection of patient group (n = 49, Tscore T-score > -1.7), 1.463 ± 0.174, 1.327 ± 0.147 μg/ml in Severe patient group (T-score < -1.7); respectively. Mean ± SD plasma level of lead and cadmium was 168.42 ± 9.61 ng/l, 2.91 ± 0.18 ng/ml in control group, 176.13 ± 8.64 ng/l, 2.97 ± 0.21 ng/ml in TP, 176.43 ± 13.2 ng/l, 2.99 ± 0.1 ng/ml in mild patients, 221.44 ± 20 ng/l and 3.80 ± 0.70 ng/ml in severe patient group, respectively. In this study plasma zinc, copper, lead & cadmium concentrations were higher in the patients than in the control, though differences were not significant. However, differences were higher between the controls and patients with severe disease (T-score < -1.7). In addition adjusted T-score of femur with age and BMI showed negative significant correlation with plasma levels of zinc and lead in total participants (p < 0.05, r = -0.201, p = 0.044, r = -0.201). It seems that more extensive study with larger ample size might supply definite results about this association for copper and cadmium.

  9. Enhancing Potentially Plant-Available Lead Concentrations in Contaminated Residential Soils Using a Biodegradable Chelating Agent

    Science.gov (United States)

    Andra, S.; Datta, R.; Sarkar, D.; Saminathan, S.

    2007-12-01

    Chelation of heavy metals is an important factor in enhancing metal solubility and, hence, metal availability to plants to promote phytoremediation. In the present study, we compared the effects of application of a biodegradable chelating agent, namely, ethylenediaminedisuccinic acid (EDDS) on enhancing plant available form of lead (Pb) in Pb-based paint contaminated residential soils compared to that of a more commonly used, but non-biodegradable chelate, i.e., ethylenediaminetetraacetic acid (EDTA). Development of a successful phytoremediation model for metals such as Pb depends on a thorough understanding of the physical and chemical properties of the soil, along with the optimization of a chelate treatment to mobilize Pb from `unavailable' pools to potentially plant available fraction. In this context, we set out to perform batch incubation experiments to investigate the effectiveness of the two aforementioned chelates in enhancing plant available Pb at four different concentrations (0, 5, 10 and 15 mM/kg soil) and three treatment durations (0, 10 and 30 days). We selected 12 contaminated residential soils from two major metropolitan areas (San Antonio, TX and Baltimore, MD) with varying soil physico-chemical properties - the soils from San Antonio were primarily alkaline and those from Baltimore were typically acidic. Total soil Pb concentrations ranged between 256 mg/kg and 4,182 mg/kg. Our results show that both chelates increased the solubility of Pb, otherwise occluded in the complex soil matrix. For both EDTA and EDDS, the exchangeable concentrations of soil Pb also increased with increase in chelate concentration and incubation time. The most effective treatment was 15 mM chelate kg-1 soil incubated for 30 days, which caused many fold increase in potentially plant available Pb (a combination of the soluble and exchangeable fractions) relative to the unamended controls. Step wise multiple linear regression analysis using chelate-extractable Pb and soil

  10. Concentration trends for lead and calcium-normalized lead in fish fillets from the Big River, a mining-contaminated stream in southeastern Missouri USA

    Science.gov (United States)

    Schmitt, Christopher J.; McKee, Michael J.

    2016-01-01

    Lead (Pb) and calcium (Ca) concentrations were measured in fillet samples of longear sunfish (Lepomis megalotis) and redhorse suckers (Moxostoma spp.) collected in 2005–2012 from the Big River, which drains a historical mining area in southeastern Missouri and where a consumption advisory is in effect due to elevated Pb concentrations in fish. Lead tends to accumulated in Ca-rich tissues such as bone and scale. Concentrations of Pb in fish muscle are typically low, but can become elevated in fillets from Pb-contaminated sites depending in part on how much bone, scale, and skin is included in the sample. We used analysis-of-covariance to normalize Pb concentration to the geometric mean Ca concentration (415 ug/g wet weight, ww), which reduced variation between taxa, sites, and years, as was the number of samples that exceeded Missouri consumption advisory threshold (300 ng/g ww). Concentrations of Pb in 2005–2012 were lower than in the past, especially after Ca-normalization, but the consumption advisory is still warranted because concentrations were >300 ng/g ww in samples of both taxa from contaminated sites. For monitoring purposes, a simple linear regression model is proposed for estimating Ca-normalized Pb concentrations in fillets from Pb:Ca molar ratios as a way of reducing the effects of differing preparation methods on fillet Pb variation.

  11. Basic mechanism leading to stimulation of glycogenolysis by isoproterenol, EGF, elevated extracellular K+ concentrations, or GABA.

    Science.gov (United States)

    Xu, Junnan; Song, Dan; Bai, Qiufang; Cai, Liping; Hertz, Leif; Peng, Liang

    2014-04-01

    Glycogenolysis, in brain parenchyma an astrocyte-specific process, has changed from being envisaged as an emergency procedure to playing central roles during brain response to whisker stimulation, memory formation, astrocytic K(+) uptake and stimulated release of ATP. It is activated by several transmitters and by even very small increases in extracellular K(+) concentration, and to be critically dependent upon an increase in free cytosolic Ca(2+) concentration ([Ca(2+)]i), whereas cAMP plays only a facilitatory role together with increased [Ca(2+)]i. Detailed knowledge about the signaling pathways eliciting glycogenolysis is therefore of interest and was investigated in the present study in well differentiated cultures of mouse astrocytes. The β-adrenergic agonist isoproterenol stimulated glycogenolysis by a β1-adrenergic effect, which initiated a pathway in which cAMP/protein kinase A activated a Gi/Gs shift, leading to Ca(2+)-activated glycogenolysis. Inhibition of this pathway downstream of cAMP but upstream of the Gi/Gs shift abolished the glycogenolysis. However, inhibitors operating downstream of the Ca(2+)-sensitive step, but preventing transactivation-mediated epidermal growth factor (EGF) receptor stimulation, a later step in the activated pathway, also caused inhibition of glycogenolysis. For this reason the effect of EGF was investigated and it was found to be glycogenolytic. Large increases in extracellular K(+) activated glycogenolysis by a nifedipine-inhibited L-channel opening allowing influx of Ca(2+), known to be glycogenolysis-dependent. Small increases (addition of 5 mM KCl) caused a smaller effect by a similarly glycogenolysis-reliant opening of an IP3 receptor-dependent ouabain signaling pathway. The same pathway could be activated by GABA (also in brain slices) due to its depolarizing effect in astrocytes.

  12. A Large X-ray Flare from a Single Weak-lined T Tauri Star TWA-7 Detected with MAXI GSC

    CERN Document Server

    Uzawa, Akiko; Morii, Mikio; Yamazaki, Kyohei; Kawai, Nobuyuki; Matsuoka, Masaru; Nakahira, Satoshi; Serino, Motoko; Matsumura, Takanori; Mihara, Tatehiro; Tomida, Hiroshi; Ueda, Yoshihiro; Sugizaki, Mutsumi; Ueno, Shiro; Daikyuji, Arata; Ebisawa, Ken; Eguchi, Satoshi; Hiroi, Kazuo; Ishikawa, Masaki; Isobe, Naoki; Kawasaki, Kazuyoshi; Kimura, Masashi; Kitayama, Hiroki; Kohama, Mitsuhiro; Kotani, Taro; Nakagawa, Yujin E; Nakajima, Motoki; Negoro, Hitoshi; Ozawa, Hiroshi; Shidatsu, Megumi; Sootome, Tetsuya; Sugimori, Kousuke; Suwa, Fumitoshi; Tsunemi, Hiroshi; Usui, Ryuichi; Yamamoto, Takayuki; Yamaoka, Kazutaka; Yoshida, Atsumasa

    2011-01-01

    We present a large X-ray flare from a nearby weak-lined T Tauri star TWA-7 detected with the Gas Slit Camera (GSC) on the Monitor of All-sky X-ray Image (MAXI). The GSC captured X-ray flaring from TWA-7 with a flux of $3\\times10^{-9}$ ergs cm$^{-2}$ s$^{-1}$ in 2--20 keV band during the scan transit starting at UT 2010-09-07 18:24:30.The estimated X-ray luminosity at the scan in the energy band is 3$\\times10^{32}$ ergs s$^{-1}$,indicating that the event is among the largest X-ray flares fromT Tauri stars.Since MAXI GSC monitors a target only during a scan transit of about a minute per 92 min orbital cycle, the luminosity at the flare peak might have been higher than that detected. At the scan transit, we observed a high X-ray-to-bolometric luminosity ratio, log $L_{\\rm X}/L_{\\rm bol}$ = $-0.1^{+0.2}_{-0.3}$; i.e., the X-ray luminosity is comparable to the bolometric luminosity. Since TWA-7 has neither an accreting disk nor a binary companion, the observed event implies that none of those are essential to gene...

  13. Treatment of mine drainage generated by lead-zinc concentration plant

    Institute of Scientific and Technical Information of China (English)

    曾科; 覃文庆; 焦芬; 何名飞; 孔令强

    2014-01-01

    The purification efficiency in the treatment of the mine drainage generated by the mineral processing industry in Mengzi, Yunnan Project, China, was investigated, and the influences of the treated drainage on the mineral electrodes’ electrochemical behaviors were tested. Experiments with different doses of polyacrylamide (PAM) and polymeric ferric sulfate (PFS) at different pH values were carried out, and the advanced purification by activated carbon (AC) was conducted. Compared with PFS, the better coagulant for removal efficiency is PAM, under the optimal conditions, the removals of Pb2+, Zn2+, Cu2+and COD reduction from solution were 94.8%, 79.9%, 87.6% and 85%, respectively. In the advanced purification, the particle size of activated carbon and agitation time played important roles in the removal efficiency. Each pollute concentration could meet the emission standard of pollutants for lead and zinc industry (GB25466-2010). The wastewater without treatment affected galena and sphalerite electrochemical behaviors greatly, after treatment by the technology, the effects disappeared, which proved the reliability of the technology for wastewater treatment.

  14. Calorie restriction at increasing levels leads to augmented concentrations of corticosterone and decreasing concentrations of testosterone in rats.

    Science.gov (United States)

    Levay, Elizabeth A; Tammer, Amanda H; Penman, Jim; Kent, Stephen; Paolini, Antonio G

    2010-05-01

    The influence of calorie restriction (CR) on increasing life span, enhancing immunocompetence, and reducing the incidence of age-related diseases is well established. Evidence points to the involvement of neuroendocrine alterations in these beneficial effects. Accordingly, we hypothesized that CR will result in significant alterations to the hormones investigated. Little attention has been directed toward ascertaining the doses of CR required to obtain such alterations and, indeed, whether a dose-response exists. Adult rats were subjected to 1 of 5 dietary regimens: control, CR12.5%, CR25%, CR37.5%, or CR50%. Rats were decapitated 3 weeks following the onset of restriction; and trunk blood was collected and assayed for concentrations of serum adrenocorticotropic hormone, corticosterone, and testosterone, as well as plasma concentrations of noradrenalin and adrenalin. No effect was found as a result of dietary manipulation for serum concentrations of adrenocorticotropic hormone. However, all doses of CR resulted in increased serum corticosterone in a dose-response trend. A dose-response was also observed for serum testosterone, with higher doses of CR associated with lower testosterone. Concentrations of noradrenalin were not found to be altered by any CR dose, although a trend toward a down-regulation at CR50% was observed. Plasma adrenalin displayed a biphasic distribution with reductions observed at CR25% and CR50%, although the down-regulations only attained statistical significance relative to the CR37.5% and not the control group. As well as reporting the effect of CR on multiple hormones within individual animals, these results go some way in determining the optimal levels of CR needed to induce neuroendocrinologic alterations.

  15. Analysis of lead concentration in forager stingless bees Trigona sp. (hymenoptera: Apidae) and propolis at Cilutung and Maribaya, West Java

    Science.gov (United States)

    Safira, Nabila; Anggraeni, Tjandra

    2015-09-01

    Several studies had shown that lead (Pb) in the environment could accumulate in bees, which in turn could affect the quality of the resulting product. In this study, forager stingless bees (Trigona sp.) and its product (propolis) collected from a stingless bees apiculture. This apiculture had two apiary sites which were distinguished by its environmental setting. Apiary site in Cilutung had a forest region environmental setting, while apiary site in Maribaya was located beside the main road. The objective of this study was to determine the extent of lead concentration in propolis originated from both apiary sites and establish the correlation between lead concentration in propolis and lead level in forager stingless bees. Forager bees and propolis samples were originated from 50 bees colonies (Cilutung) and 44 bees colonies (Maribaya). They were analyzed using AAS-GF (Atomic Absorption Spectrometre-Graphite Furnace) to determine the level of lead concentration. The results showed that the average level of lead in propolis originated from Cilutung (298.08±73.71 ppb) was lower than the average level of lead in forager bees which originated from Maribaya (330.64±156.34 ppb). However, these values did not show significant difference (p>0.05). There was no significant difference (p>0.05) between the average level of lead in forager bees which originated from Cilutung (118.08±30.46 ppb) and Maribaya (128.82±39.66 ppb). However, these values did not show significant difference (p>0.05). In conclusion, the average level of lead concentration in propolis in both sites had passed the maximum permission standard of lead for food in Indonesia. There was no correlation between lead concentration in propolis and forager stingless bees.

  16. Analysis of lead concentration in forager stingless bees Trigona sp. (hymenoptera: Apidae) and propolis at Cilutung and Maribaya, West Java

    Energy Technology Data Exchange (ETDEWEB)

    Safira, Nabila, E-mail: safira.nabila@ymail.com; Anggraeni, Tjandra, E-mail: tjandra@sith.itb.ac.id [School of Life Science and Technology, Institut Teknologi Bandung – Jalan Ganesha 10, Bandung (Indonesia)

    2015-09-30

    Several studies had shown that lead (Pb) in the environment could accumulate in bees, which in turn could affect the quality of the resulting product. In this study, forager stingless bees (Trigona sp.) and its product (propolis) collected from a stingless bees apiculture. This apiculture had two apiary sites which were distinguished by its environmental setting. Apiary site in Cilutung had a forest region environmental setting, while apiary site in Maribaya was located beside the main road. The objective of this study was to determine the extent of lead concentration in propolis originated from both apiary sites and establish the correlation between lead concentration in propolis and lead level in forager stingless bees. Forager bees and propolis samples were originated from 50 bees colonies (Cilutung) and 44 bees colonies (Maribaya). They were analyzed using AAS-GF (Atomic Absorption Spectrometre–Graphite Furnace) to determine the level of lead concentration. The results showed that the average level of lead in propolis originated from Cilutung (298.08±73.71 ppb) was lower than the average level of lead in forager bees which originated from Maribaya (330.64±156.34 ppb). However, these values did not show significant difference (p>0.05). There was no significant difference (p>0.05) between the average level of lead in forager bees which originated from Cilutung (118.08±30.46 ppb) and Maribaya (128.82±39.66 ppb). However, these values did not show significant difference (p>0.05). In conclusion, the average level of lead concentration in propolis in both sites had passed the maximum permission standard of lead for food in Indonesia. There was no correlation between lead concentration in propolis and forager stingless bees.

  17. A Greenhouse Study on Lead Uptake and Antioxidant Enzyme Activities in Vetiver Grass (Vetiveria zizanioides) as a Function of Lead Concentration and Soil Physico-Chemical Properties

    Science.gov (United States)

    Andra, S. P.; Datta, R.; Sarkar, D.; Saminathan, S. K.

    2006-05-01

    Lead (Pb) is a toxic non-essential metal that can cause permanent learning disabilities, retardation, mental and behavioral problems in children. Lead accumulation in soils result from weathering, chipping, scraping, sanding and sand blasting of housing structures constructed prior to 1978, bearing lead-based paint. The primary objective of this study is to develop a cost-effective, chelate-assisted phytoremediation for cleaning up lead contaminated soils. Soils are a unique environment of diverse physical and chemical characteristics that influence the extent of phytoavailable (labile) Pb forms. The success of phytoremediation strategy depends on the physiological/ biochemical tolerance of the plants to lipid peroxidation induced by Pb at sub-lethal levels. Oxidative challenge is alleviated by antioxidant compounds, but more importantly by the induction of antioxidant enzymes, which are crucial for scavenging reactive oxygen species (ROS) and terminating lipid peroxidation chain reaction. A column study was conducted in a temperature and humidity-controlled greenhouse setting to assess the extent of Pb phytoextraction and antioxidant response in a lead accumulator, vetiver grass (Vetiveria zizanioides). Treatments consisted of a randomized block arrangement of 4 soil types (Immokalee, Pahokee Muck, Tobosa, and Millhopper) and 3 soil Pb concentrations [normal - 400 mg/kg lead (following federal soil standards for lead), moderate - 800 mg/kg lead, and excessive - 1200 mg/kg lead] in 4 replicates. At the end of 6 months, selected columns were amended with a biodegradable chelating agent, ethylenediamene disuccinate (10 mmol/ kg EDDS), to mobilize Pb and enhance Pb uptake by vetiver. Total and exchangeable (labile) Pb were correlated with phytoextracted Pb, and levels of antioxidant enzymes viz., superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the root and shoot tissues of vetiver grass. Results indicate that Pb uptake and antioxidant

  18. Examination of lead concentrations in new decorative enamel paints in four countries with different histories of activity in lead paint regulation

    Energy Technology Data Exchange (ETDEWEB)

    Clark, C. Scott, E-mail: clarkcs@ucmail.uc.edu [Department of Environmental Health, University of Cincinnati (United States); International POPS Elimination Network (IPEN), San Francisco (United States); Kumar, Abhay; Mohapatra, Piyush; Rajankar, Prashant [Toxics Link, New Delhi (India); Nycz, Zuleica [APROMAC Environmental Protection Association and Toxisphera Environmental Health Association, Curitiba, Parana (Brazil); Hambartsumyan, Amalia [Greenwomen, Almaty (Kazakhstan); Astanina, Lydia [Khazer Ecological and Cultural Non-Governmental Organization, Yerevan (Armenia); Roda, Sandy; Lind, Caroline; Menrath, William; Peng, Hongying [Department of Environmental Health, University of Cincinnati (United States)

    2014-07-15

    Paints with high lead concentrations (ppm) continue to be sold around the world in many developing countries and those with economies in transition representing a major preventable environmental health hazard that is being increased as the economies expand and paint consumption is increasing. Prior lead paint testing had been performed in Brazil and India and these countries were selected to examine the impact of a new regulatory limit in Brazil and the impact of efforts of non-governmental organizations and others to stop the use of lead compounds in manufacturing paints. Armenia and Kazakhstan, in Central Asia, were selected because no information on lead concentration in those regions was available, no regulatory activities were evident and non-governmental organizations in the IPEN network were available to participate. Another objective of this research was to evaluate the lead loading (µg/cm{sup 2}) limit determined by X-Ray Fluorescence (XRF) for areas on toys that are too small to obtain a sample of sufficient size for laboratory analysis. The lead concentrations in more than three-fourths of the paints from Armenia and Kazakhstan exceeded 90 ppm, the limit in the United States, and 600 ppm, the limit in Brazil. The percentages were about one-half as high in Brazil and India. The average concentration in paints purchased in Armenia, 25,000 ppm, is among the highest that has been previously reported, that in Kazakhstan, 15,700 ppm, and India, 16,600, about median. The average concentration in Brazil, 5600 ppm, is among the lowest observed. Paints in Brazil that contained an average of 36,000 ppm before the regulatory limit became effective were below detection (<9 ppm) in samples collected in the current study. The lack of any apparent public monitoring of paint lead content as part of regulatory enforcement makes it difficult to determine whether the regulation was a major factor contributing to the decline in lead use in these paints. Using data from the

  19. Genotypic and environmental variation in cadmium, chromium, arsenic, nickel, and lead concentrations in rice grains

    Institute of Scientific and Technical Information of China (English)

    CHENG Wang-da; ZHANG Guo-ping; YAO Hai-gen; WU Wei; XU Min

    2006-01-01

    Genotypic and environmental variation in Cd, Cr, As, Ni and Pb concentrations of grains, and the relationships between these heavy metals and Fe, Zn were investigated using 9 rice genotypes grown in 6 locations for two successive years.Significant genotypic variation was detected in the five heavy metal concentrations in grains, indicating the possibility to reduce the concentration of these heavy metals in grains through breeding approach. The environmental effect varied with metal, with Pb and Ni having greater variation than the other three metals. There was significant genotype-environment (location) interaction of the concentrations of all five heavy metals in grains, suggesting the importance of cultivar choice in producing rice with low heavy metal concentrations in grains for a given location. Correlation analysis showed that Cd and As, Cr and Ni, and As and Pb concentrations in rice grains were closely associated, and that Ni concentration in grains was negatively correlated with Zn concentration.

  20. Concentrations of lead in blood, hair and saliva of German children living in three different areas of traffic density

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelm, M.; Pesch, A.; Rostek, U. [Institute of Hygiene, Social and Environmental Medicine, Ruhr-University, Bochum (Germany); Begerow, J.; Ranft, U. [Medical Institute of Environmental Hygiene at the Heinrich-Heine-University, Duesseldorf (Germany); Schmitz, N.; Idel, H. [Institute of Hygiene, Heinrich-Heine-University, Duesseldorf (Germany)

    2002-10-07

    Lead contents in hair, whole blood and saliva were determined for 245 healthy children (121 male, 124 female, age: 8-10 years) from three residential areas of Duesseldorf (North-Rhine-Westphalia, Germany) with different traffic densities. The geometric mean for the lead content in hair was found to be 0.87 {mu}g/g (range: 0.2-9.9 {mu}g/g) for the entire test group. While the levels of lead in hair in the suburban population were significantly lower than in the two city centre populations, no significant difference concerning the lead content in hair could be detected in the latter. The geometric mean for lead concentration in whole blood amounted to 25.0 {mu}g/l (range: 8.0-154 {mu}g/l). There was no significant difference between the sub-groups. The lead concentrations found in saliva were rather low (range: <1.5-47.0 {mu}g/l). Of the values, 89% were below the detection limit of 1.5 {mu}g/l. Due to reduced levels of lead in fuel, the present study exposes that the amount of lead in the children examined has further decreased compared to preceding surveys. The correlation between the lead content in hair and the road traffic density was not corroborated by the findings with regard to amounts of lead found in blood, indicating that residual lead from fuel does not result in a substantial burden of lead found in the whole body. In contrast to levels of lead found in blood, levels of lead found in hair may be influenced more by environmental conditions. Saliva is not a suitable material for biological monitoring with respect to lead exposure in children.

  1. Arsenic, Cadmium, Chromium, Lead, Mercury and Selenium Concentrations in Pine Snakes (Pituophis melanoleucus) from the New Jersey Pine Barrens.

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Zappalorti, Robert; Pittfield, Taryn; DeVito, Emile

    2017-05-01

    Top trophic level predators are at risk from bioaccumulation of heavy metals from their prey. Using nondestructively collected tissues as a method of assessing metal concentrations in snakes is useful for populations that are threatened or declining. This paper reports concentrations of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and selenium (Se) in tissues of Northern pine snakes (Pituophis melanoleucus) from the New Jersey Pine Barrens, a relatively pristine, undisturbed habitat. We also determined if skin is an appropriate indicator of internal concentrations and identified the factors (tissue, year of collection, length, sex) that might explain variations in metal concentrations. Because they can grow to 2-m long and live for 25 years, we suggest that these snakes might accumulate heavy metals. Multiple regression models were significant, explaining 16% (lead) to 61% (mercury) of variation by tissue type. For mercury and chromium, size also was significant. The highest concentrations were in liver and kidney for all metals, except chromium and lead. Mercury concentrations in tissues were within the range reported for other snakes and were below effects concentrations in reptiles. The concentrations in skin were correlated with all internal tissues for mercury and for all internal tissues except heart for cadmium. These data show that shed skin can be used as an indicator of metals in pine snakes and that, at present, concentrations of heavy metals in this population are within the range of those found in other snake species from uncontaminated sites.

  2. Relationship between blood lead concentrations and learning achievement among primary school children in Taiwan.

    Science.gov (United States)

    Wang, Chao-Ling; Chuang, Hung-Yi; Ho, Chi-Kung; Yang, Chun-Yuh; Tsai, Jin-Lian; Wu, Ting-Shan; Wu, Trong-Neng

    2002-05-01

    Over the past 20 years lead has been proven to exert an influence on the intelligence of children. Especially for children exposed to environmental lead, average blood lead was often lower than the officially recognized intoxication level. Because Kaohsiung is an industrial area in Taiwan and lead exposure is an important environmental issue, we attempted to ascertain the extent to which environmental lead influences the achievement of primary school children. We randomly selected 934 children from 32 primary schools in 11 districts of Kaohsiung City. Blood lead levels of the children were checked, and they were administered a questionnaire about their family information. Scores of several courses were used in this study on the relationship between a child's blood lead and his or her academic performance (Ranking with his or her classmates), including Chinese (reading and writing short Chinese articles), Mathematics, History and Society, and Natural Science. Multiple regression models were done with adjustments for the confounding effects of their parents' socioeconomic levels. The mean (SD) of 934 blood lead level was 5.50 (1.86) microg/dL. Spearman's coefficient showed that class rankings in Chinese, Mathematics, Natural Science, and History and Society were all strongly associated with blood lead levels (Pmultiple regression models revealed that blood lead level exerts a stronger influence on children's language ability (Chinese) than on their ability to calculate (Mathematics). Our results suggest that environmental lead exposure adversely affects a child's academic achievement, making a direct link between exposure to lead and academic attainment. 2002 Elsevier Science (USA)

  3. Concentration Mechanism of Ore-Forming Fluid in Huize Lead-Zinc Deposits, Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhenliang; Huang Zhilong; Rao Bing; Guan Tao; Yan Zaifei

    2005-01-01

    highly concentrated, and metallic minerals began to precipitate from the fluid on a great scale. The high-grade lead-zinc deposits were formed when the fluid was under saturation or over-saturation conditions.

  4. Concentration of China’s Lead & Zinc Industry Drops,Rather Than Rises

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>This year has seen China’s lead & zinc industry go up dramatically in sales revenue and fixed investment and its proportion in national GDP grow as well.In contrast to the global giants, however,China’s lead & zinc industry is still restrained by such problems as resource bottle- neck,less(ratber than more)industrial concen-

  5. Stunting is associated with blood lead concentration among Bangladeshi children aged 2-3 years.

    Science.gov (United States)

    Gleason, Kelsey M; Valeri, Linda; Shankar, A H; Hasan, Md Omar Sharif Ibne; Quamruzzaman, Quazi; Rodrigues, Ema G; Christiani, David C; Wright, Robert O; Bellinger, David C; Mazumdar, Maitreyi

    2016-11-04

    Lead toxicity is of particular public health concern given its near ubiquitous distribution in nature and established neurotoxicant properties. Similar in its ubiquity and ability to inhibit neurodevelopment, early childhood stunting affects an estimated 34 % of children under 5 in low- and middle-income countries. Both lead and stunting have been shown to be associated with decreased neurodevelopment, although the relationship between these childhood burdens is underexplored. The association between lead exposure and stunting has been previously established, yet limited data are available on susceptibility windows. Whole blood lead samples were collected from rural Bangladeshi children at delivery (umbilical cord blood) and at age 20-40 months (fingerstick blood). Stunting was determined using the Child Growth Standards developed from the World Health Organization Multicentre Growth Reference Study. Children with height for age lead levels were 3.1 (1.6-6.3) μg/dl and 4.2 (1.7-7.6) μg/dl, respectively. In adjusted multivariable regression models, the odds of stunting at 20-40 months increased by 1.12 per μg/dl increase in blood lead level (OR = 1.12, 95 % CI: 1.02-1.22). No association was found between cord blood lead level and risk of stunting (OR = 0.97, 95 % CI: 0.94-1.00). There is a significant association between stunting and concurrent lead exposure at age 20-40 months. This association is slightly attenuated after controlling for study clinic site. Additional research including more precise timing of lead exposure during these critical 20-40 months is needed.

  6. Blood lead concentrations in wild birds from a polluted mining region at Villa de La Paz, San Luis Potosi, Mexico.

    Science.gov (United States)

    Chapa-Vargas, Leonardo; Mejia-Saavedra, Jose J; Monzalvo-Santos, Karina; Puebla-Olivares, Fernando

    2010-01-01

    This investigation was undertaken to determine the concentrations of lead in bird blood samples from a mining region in central Mexico and to compare concentrations among several different feeding guilds. The study took place in the Mexican state of San Luis Potosi in a region known as "Villa de la Paz." This is one of the most intensely exploited mining regions in central Mexico and has been actively mined for over four centuries. Lead concentrations from bird blood samples taken from four polluted sites were significantly higher than those from a control, unpolluted site (F = 6.3, P birds from a highly polluted site were higher than those from a site that has intermediate pollution levels (P birds had significantly lower lead concentrations compared to granivores, frugivores-insectivores, and omnivores (F = 4.86, P = 0.004), and a large proportion of all individuals had blood lead concentrations indicative of low, sub-lethal toxic effects. Finally, in two polluted sites, remarkably small numbers of insectivore-frugivores, and granivores were trapped, and in one polluted site a large number of insectivores was trapped (X(2) = 29.9, P = 0.03), and no differences in proportions of migrants and non-migrants were found among sampling sites (X(2) = 0.6, P = 0.96). To date, it has not been determined to what extent constant exposure to these levels of pollution can influence health at the individual level, lifespan, and, therefore, population demography of birds from this region.

  7. Detection of lead ions in picomolar concentration range using underpotential deposition on silver nanoparticles-deposited glassy carbon electrodes.

    Science.gov (United States)

    Sivasubramanian, R; Sangaranarayanan, M V

    2011-09-30

    The efficacy of silver-deposited glassy carbon electrode for the determination of lead ions at the sub-nanomolar concentration ranges is investigated. The silver nanoparticles are electrodeposited on glassy carbon electrode using chronoamperometry and the electrode surface is characterized using SEM. Lead ions are detected in the region of underpotential deposition. The analysis is performed in square wave mode in the stripping voltammetry without the removal of oxygen. The detection limit of 10 pM has been obtained with a constant potential of -0.7 V during the electrodeposition step for a period of 50s. The interference of surfactants in the detection of lead ions is also studied.

  8. Lead and Cadmium Concentration in Agricultural Crops (Lettuce, Cabbage, Beetroot, and Onion of Isfahan Province, Iran

    Directory of Open Access Journals (Sweden)

    Reza Mohajer

    2014-07-01

    Conclusion: The findings of this study indicated that although most of the sampling plants were contaminated with lead and cadmium, the estimated daily intake of each metal (EDI showed that except lead in lettuce, other crops have EDI below the provisional tolerable daily intake (PTDI recommended by the Institute of Standards and Industrial Research of Iran. In order to better management, preventing pollution and also finding the origin of elements, analyzing heavy metals content in soil, water, and dust of this region is recommended.

  9. Postnatal adrenalectomy impairs urinary concentrating ability by increased COX-2 and leads to renal medullary injury

    DEFF Research Database (Denmark)

    Stubbe, Jane; Madsen, Kirsten; Nielsen, Finn T

    2007-01-01

    at postnatal day 10. Adrenalectomized rats were divided into no steroid substitution (ADX), corticosterone replacement (ADX-C), and corticosterone and DOCA substitution (ADX-CD) groups that received subcutaneous pellets with steroids. Without replacement, pups failed to thrive and exhibited impaired urinary...... deprivation, parecoxib attenuated weight loss and the increase in plasma Na+ concentration and osmolality. It is concluded that mineralocorticoid is required for normal postnatal development of the renal medulla. COX-2 contributes to impaired urine-concentrating ability, NaCl loss, and extracellular volume...

  10. Blood Metal Concentrations of Manganese, Lead, and Cadmium in Relation to Serum Ferritin Levels in Ohio Residents

    Science.gov (United States)

    The objectives of this study were to assess fcrritin-specific profiles of blood metal concentrations such as manganese, lead, and cadmium and to evaluate whether ferritin may affect the behavior of the blood metals in relation to menstruation, menopause, or sex in Ohio residents....

  11. Organic and inorganic amendments affect soil concentration and accumulation of cadmium and lead in wheat in calcareous alkaline soils

    Science.gov (United States)

    Irrigation with untreated effluent in periurban agriculture could result in accumulation and bioconcentrations of cadmium (Cd) and lead (Pb). Different amendments were used to investigate their effect on availability, concentration, and uptake of metals by wheat in texturally different soils. Crop w...

  12. Blood Metal Concentrations of Manganese, Lead, and Cadmium in Relation to Serum Ferritin Levels in Ohio Residents

    Science.gov (United States)

    The objectives of this study were to assess fcrritin-specific profiles of blood metal concentrations such as manganese, lead, and cadmium and to evaluate whether ferritin may affect the behavior of the blood metals in relation to menstruation, menopause, or sex in Ohio residents....

  13. Concentrations of lead, cadmium and barium in urban garden-grown vegetables: the impact of soil variables.

    Science.gov (United States)

    McBride, Murray B; Shayler, Hannah A; Spliethoff, Henry M; Mitchell, Rebecca G; Marquez-Bravo, Lydia G; Ferenz, Gretchen S; Russell-Anelli, Jonathan M; Casey, Linda; Bachman, Sharon

    2014-11-01

    Paired vegetable/soil samples from New York City and Buffalo, NY, gardens were analyzed for lead (Pb), cadmium (Cd) and barium (Ba). Vegetable aluminum (Al) was measured to assess soil adherence. Soil and vegetable metal concentrations did not correlate; vegetable concentrations varied by crop type. Pb was below health-based guidance values (EU standards) in virtually all fruits. 47% of root crops and 9% of leafy greens exceeded guidance values; over half the vegetables exceeded the 95th percentile of market-basket concentrations for Pb. Vegetable Pb correlated with Al; soil particle adherence/incorporation was more important than Pb uptake via roots. Cd was similar to market-basket concentrations and below guidance values in nearly all samples. Vegetable Ba was much higher than Pb or Cd, although soil Ba was lower than soil Pb. The poor relationship between vegetable and soil metal concentrations is attributable to particulate contamination of vegetables and soil characteristics that influence phytoavailability.

  14. COX-2 disruption leads to increased central vasopressin stores and impaired urine concentrating ability in mice

    DEFF Research Database (Denmark)

    Norregaard, Rikke; Madsen, Kirsten Morill; Hansen, Pernille Bl

    2011-01-01

    It was hypothesized that cyclooxygenase-2 (COX-2) activity promotes urine concentrating ability through stimulation of vasopressin (AVP) release after water deprivation (WD). COX-2-deficient (COX-2(-/-), C57BL/6) and wild-type (WT) mice were water deprived for 24 h, and water balance, central AVP...

  15. Investigation of Heavy Metals Concentrations in the Water Wells Close to Zanjan Zinc and Lead Smelting Plant

    Directory of Open Access Journals (Sweden)

    M Nourani

    2008-09-01

    Full Text Available Background and Objectives: Heavy metals processing industry has always been a major cause of concern which affects soils, surface waters, ground waters and river sediments contaminations. Thus, the Zanjan Zinc and Lead Smelting Plant has been considered as a potential source of contamination."nMterials and Methods: This cross-sectional study has been conducted in February 2008 in the site region .The concentrations of Lead, Zinc and Cadmium have been assessed. The samples have been taken from 17 wells and atomic absorption spectrophotometeric method has been used to assess the samples. In order to find out and locate the exact situation of the wells under study, Global Positioning System instrument has been used. The correlation between the concentration of each metal and the distance of studied well from the plant has been assessed too."nResults: The findings of this study showed that lead and cadmium concentrations were 53% and 59% respectively out of the guideline values of World Health Organization."nConclusion: The concentration of Zinc was lower than both national and international values in all samples. As the heavy metal concentration is very important for human health status, the other fields of study like heavy metal air pollution effects and related diseases and conditions should be studied and assessed.

  16. Deer exposed to exceptionally high concentrations of lead near the continental mine in Idaho, USA

    Science.gov (United States)

    Beyer, W.N.; Gaston, G.; Brazzle, R.; O'Connell, A.F.; Audet, D.J.

    2007-01-01

    Habitat surrounding the inactive Continental Mine in northern Idaho, USA, supports bear (Ursus arctos, Ursus americanus), moose (Alces alces), elk (Cervus elaphus), woodland caribou (Rangifer tarandus caribou), and abundant mule (Odocoileus hemionus) and white-tailed deer (Odocoileus virginianus). Tailings on the mining site were capped and remediated in 2003 to reduce environmental exposure of surrounding soil and sediments of Blue Joe Creek, downslope of the mine. Before capping, the mean Pb concentration in deer pellets collected on-site was 920 mg/kg of Pb (dry wt). This exposure, if chronic, would be comparable to an exposure that could be lethal to cattle or horses. Surprisingly, the mean pellet Pb concentration of 950 mg/kg in 2004 was as high as it was before remediation, and it was related to a high rate of soil ingestion. Mean soil content of the pellets collected from the capped site in 2004 was 22% dry weight, estimated from the acid-insoluble ash, a marker of soil ingestion. Clumps of sand and bits of rock were observed inside some of the pellets, and Pb concentrations in the pellets were correlated (p soil content. Although terrestrial risk assessments generally estimate exposure from diets and from incidentally ingested soil, the deer at this site were directly ingesting contaminated soil or mining waste. The mean Pb concentration of this ingested soil was estimated as 6,700 mg/kg and the maximum as 25,000 mg/kg, well above the Pb concentrations measured in the remediated cap. The deer seemed to be ingesting soil or mining waste from one or more small but highly contaminated sources located beyond the remediated cap.

  17. Screening for cardiovascular safety: a structure-activity approach for guiding lead selection of melanin concentrating hormone receptor 1 antagonists.

    Science.gov (United States)

    Kym, Philip R; Souers, Andrew J; Campbell, Thomas J; Lynch, John K; Judd, Andrew S; Iyengar, Rajesh; Vasudevan, Anil; Gao, Ju; Freeman, Jennifer C; Wodka, Dariusz; Mulhern, Mathew; Zhao, Gang; Wagaw, Seble H; Napier, James J; Brodjian, Sevan; Dayton, Brian D; Reilly, Regina M; Segreti, Jason A; Fryer, Ryan M; Preusser, Lee C; Reinhart, Glenn A; Hernandez, Lisa; Marsh, Kennan C; Sham, Hing L; Collins, Christine A; Polakowski, James S

    2006-04-06

    An inactin-anesthetized rat cardiovascular (CV) assay was employed in a screening mode to triage multiple classes of melanin-concentrating hormone receptor 1 (MCHr1) antagonists. Lead identification was based on a compound profile producing high drug concentration in both plasma (>40 microM) and brain (>20 microg/g) with optimization activities on multiple classes of MCHr1 antagonists were terminated. After providing evidence that the cardiovascular liabilities were not a function of MCHr1 antagonism, continued screening identified the chromone-substituted aminopiperidine amides as a class of MCHr1 antagonists that demonstrated a safe cardiovascular profile at high drug concentrations in both plasma and brain. The high incidence of adverse cardiovascular effects associated with an array of MCHr1 antagonists of significant chemical diversity, combined with the stringent safety requirements for antiobesity drugs, highlight the importance of incorporating cardiovascular safety assessment early in the lead selection process.

  18. Effect of ash circulation in gasification melting system on concentration and leachability of lead in melting furnace fly ash.

    Science.gov (United States)

    Okada, Takashi; Suzuki, Masaru

    2013-11-30

    In some gasification-melting plants, generated melting furnace fly ash is returned back to the melting furnace for converting the ash to slag. This study investigated the effect of such ash circulation in the gasification-melting system on the concentration and leachability of lead in the melting furnace fly ash. The ash circulation in the melting process was simulated by a thermodynamic calculation, and an elemental analysis and leaching tests were performed on a melting furnace fly ash sample collected from the gasification-melting plant with the ash circulation. It was found that by the ash circulation in the gasification-melting, lead was highly concentrated in the melting furnace fly ash to the level equal to the fly ash from the ash-melting process. The thermodynamic calculation predicted that the lead volatilization by the chlorination is promoted by the ash circulation resulting in the high lead concentration. In addition, the lead extraction from the melting furnace fly ash into a NaOH solution was also enhanced by the ash circulation, and over 90% of lead in the fly ash was extracted in 5 min when using 0.5 mol l(-1) NaOH solution with L/S ratio of 10 at 100 °C. Based on the results, a combination of the gasification-melting with the ash circulation and the NaOH leaching method is proposed for the high efficient lead recovery. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Trace metal concentrations and lead isotopic composition in surface waters of the Northeast Pacific along the United States - Mexico boundary

    Energy Technology Data Exchange (ETDEWEB)

    Sanudo-Wilhelmy, S. (Inst. of Marine Science, Santa Cruz, CA (United States))

    1990-01-09

    To evaluate the magnitude of heavy metal contamination along the United States - Mexico boundary, trace metal concentrations (Pb, Cd, Mn, Fe, and Zn) and lead isotopic composition ([sup 204]Pb, [sup 206]Pb, [sup 207]Pb, and [sup 208]Pb) were measured along four surface water transects across the continental shelf off the Baja California Coast. The stations were located between 2 to 45 km offshore, including both coastal and open ocean locations. All the metal distributions along the transects were characterized by offshore concentration gradients. The highest trace metal concentrations occurred in coastal waters in association with high salinities and nutrient concentrations. There was also a longshore gradient in trace metal concentrations. Trace element concentrations were lower in the southern locations than along the United States - Mexico boundary, and were comparable to typical open ocean values. The relative enrichment of metals in surface waters off the northern part of Baja California was primarily associated with advection/upwelling processes, not with anthropogenic inputs. Mass balance calculations indicated that about 1% of Cd and 13% of Zn were from urban discharges. The low metal levels measured in coastal waters off the central part of Baja California were attributed to the intrusion of open ocean waters, based on hydrographic data, satellite images and lead isotopic compositions.

  20. Relationship between blood lead concentration and nutritional status among Malay primary school children in Kuala Lumpur, Malaysia.

    Science.gov (United States)

    Elias, S M; Hashim, Z; Marjan, Z M; Abdullah, A S; Hashim, J H

    2007-01-01

    A cross-sectional study was conducted to identify the relationship between blood lead concentration and nutritional status among primary school children in Kuala Lumpur. A total of 225 Malay students, 113 male and 112 female, aged 6.3 to 9.8 were selected through a stratified random sampling method. The random blood samples were collected and blood lead concentration was measured by a Graphite Furnace Atomic Absorption Spectrophotometer. The nutrient intake was determined by the 24-hour Dietary Recall method and Food Frequency Questionnaire. An anthropometric assessment was reported according to growth indices (z-scores of weight-for-age, height-for-age, and weight-for-height). The mean blood lead concentration was low (3.4 +/- 1.91 ug/dL) and was significantly different between gender. Only 14.7% of the respondents fulfilled the daily energy requirement. The protein and iron intakes were adequate for a majority of the children. However, 34.7% of the total children showed inadequate intake of calcium. The energy, protein, fat and carbohydrate intakes were significantly different by gender, that is, males had better intake than females. Majority of respondents had normal mean z-score of growth indices. Ten percent of the respondents were underweight, 2.8% wasted and 5.4% stunted. Multiple linear regression showed inverse significant relationships between blood lead concentration with children's age (beta = -0.647, p per capita income (beta = -0.001, p = 0.018). There were inverse significant relationships between blood lead concentration with children's age (beta = -0.877, p = 0.001) and calcium intake (beta = -0.011, p = 0.014) and positive significant relationship with weight-for-height (beta = 0.326, p = 0.041) among those with inadequate calcium intake. Among children with inadequate energy intake, children's age (beta = -0.621, p per capita income (beta = -0.001, p = 0.025) and protein intake (beta = -0.019, p = 0.027) were inversely and significantly related

  1. Observing the planet formation time-scale by ground-based direct imaging of planetary companions to young nearby stars Gemini\\/Hokupa'a image of TWA-5

    CERN Document Server

    Neuhäuser, R; Brandner, W; Neuhaeuser, Ralph; Potter, Dan; Brandner, Wolfgang

    2001-01-01

    Many extra-solar planets and a few planetary systems have been found indirectly by small periodic radial velocity variations around old nearby stars. The orbital characteristics of most of them are different from the planets in our solar system. Hence, planet formation theories have to be revised. Therefore, observational constraints regarding young planets would be very valuable. We have started a ground-based direct imaging search for giant planets in orbit around young nearby stars. Here, we will motivate the sample selection and will present our direct imaging observation of the very low-mass (15 to 40 Jupiter masses) brown dwarf companion TWA-5 B in orbit around the nearby young star TWA-5 A, recently obtained with the 36-element curvature-sensing AO instrument Hokupa'a of the University of Hawai'i at the 8.3m Gemini-North telescope on Mauna Kea. We could achieve a FWHM of 64 mas and 25 % Strehl. We find significance evidence for orbital motion of B around A.

  2. Effects of pH and carbonate concentration on dissolution rates of the lead corrosion product PbO(2).

    Science.gov (United States)

    Xie, Yanjiao; Wang, Yin; Singhal, Vidhi; Giammar, Daniel E

    2010-02-01

    Lead(IV) oxide is a corrosion product that can develop on lead pipes and affect lead concentrations in drinking water. Continuously stirred flow-though reactors were used to quantify the dissolution rates of plattnerite (beta-PbO(2)) at different pH values and dissolved inorganic carbon (DIC) concentrations. Organic pH buffers were not used, because several were found to be reductants for PbO(2) that accelerated its dissolution. Most plattnerite dissolution rates were on the order of 10(-10) mol/min-m(2). The rate of dissolution increased with decreasing pH and with increasing DIC. The effect of DIC is consistent with a reductive dissolution mechanism that involves the reduction of Pb(IV) to Pb(II) at the plattnerite surface followed by the formation of soluble Pb(II)-carbonate complexes that accelerate Pb(II) release from the surface. Under the experimental conditions, dissolved lead concentrations were controlled by the dissolution rate of plattnerite and not by its equilibrium solubility. A dissolution rate model was developed and can be used to predict dissolution rates of plattnerite as a function of pH and DIC.

  3. Effects of lead on Na+, K+-ATPase and hemolymph ion concentrations in the freshwater mussel Elliptio complanata

    Science.gov (United States)

    Mosher, Shad; Cope, W. Gregory; Weber, Frank X.; Shea, Damian; Kwak, Thomas J.

    2012-01-01

    Freshwater mussels are an imperiled fauna exposed to a variety of environmental toxicants such as lead (Pb) and studies are urgently needed to assess their health and condition to guide conservation efforts. A 28-day laboratory toxicity test with Pb and adult Eastern elliptio mussels (Elliptio complanata) was conducted to determine uptake kinetics and to assess the toxicological effects of Pb exposure. Test mussels were collected from a relatively uncontaminated reference site and exposed to a water-only control and five concentrations of Pb (as lead nitrate) ranging from 1 to 245 mu g/L in a static renewal test with a water hardness of 42 mg/L. Endpoints included tissue Pb concentrations, hemolymph Pb and ion (Na+, K+, Cl-, Ca2+) concentrations, and Na+, K+-ATPase enzyme activity in gill tissue. Mussels accumulated Pb rapidly, with tissue concentrations increasing at an exposure-dependent rate for the first 2 weeks, but with no significant increase from 2 to 4 weeks. Mussel tissue Pb concentrations ranged from 0.34 to 898 mu g/g dry weight, were strongly related to Pb in test water at every time interval (7, 14, 21, and 28 days), and did not significantly increase after day 14. Hemolymph Pb concentration was variable, dependent on exposure concentration, and showed no appreciable change with time beyond day 7, except for mussels in the greatest exposure concentration (245 mu g/L), which showed a significant reduction in Pb by 28 days, suggesting a threshold for Pb binding or elimination in hemolymph at concentrations near 1000 mu g/g. The Na+, K+-ATPase activity in the gill tissue of mussels was significantly reduced by Pb on day 28 and was highly correlated with tissue Pb concentration (R2 = 0.92; P = 0.013). The Na+, K+-ATPase activity was correlated with reduced hemolymph Na+ concentration at the greatest Pb exposure when enzyme activity was at 30% of controls. Hemolymph Ca2+ concentration increased significantly in mussels from the greatest Pb exposure and may

  4. HIV-1 resistance to neutralizing antibodies: Determination of antibody concentrations leading to escape mutant evolution.

    Science.gov (United States)

    Magnus, Carsten; Reh, Lucia; Trkola, Alexandra

    2016-06-15

    Broadly neutralizing antibodies against human immunodeficiency virus type 1 (HIV-1) are considered vital components of novel therapeutics and blueprints for vaccine research. Yet escape to even the most potent of these antibodies is imminent in natural infection. Measures to define antibody efficacy and prevent mutant selection are thus urgently needed. Here, we derive a mathematical framework to predict the concentration ranges for which antibody escape variants can outcompete their viral ancestors, referred to as mutant selection window (MSW). When determining the MSW, we focus on the differential efficacy of neutralizing antibodies against HIV-1 in two canonical infection routes, free-virus infection and cell-cell transmission. The latter has proven highly effective in vitro suggesting its importance for both in vivo spread as well as for escaping targeted intervention strategies. We observed a range of MSW patterns that highlight the potential of mutants to arise in both transmission pathways and over wide concentration ranges. Most importantly, we found that only when the arising mutant has both, residual sensitivity to the neutralizing antibody and reduced infectivity compared to the parental virus, antibody dosing outside of the MSW to restrict mutant selection is possible. Emergence of mutants that provide complete escape and have no considerable fitness loss cannot be prevented by adjusting antibody doses. The latter may in part explain the ubiquitous resistance to neutralizing antibodies observed in natural infection and antibody treatment. Based on our findings, combinations of antibodies targeting different epitopes should be favored for antibody-based interventions as this may render complete resistance less likely to occur and also increase chances that multiple escapes result in severe fitness loss of the virus making longer-term antibody treatment more feasible. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Blood Lead Concentration Is Not Altered by High Dose Vitamin D Supplementation in Children and Young Adults with HIV

    Science.gov (United States)

    Groleau, Veronique; Herold, Rachel A; Schall, Joan I; Wagner, Julia L; Dougherty, Kelly A; Zemel, Babette S; Rutstein, Richard M; Stallings, Virginia A

    2014-01-01

    OBJECTIVES Optimal vitamin D status is known to have beneficial health effects and vitamin D supplements are commonly used. It has been suggested that vitamin D supplementation may increase blood lead in children and adults with previous lead exposure. The objective was to determine the safety regarding lead toxicity during 12 weeks of high dose vitamin D3 supplementation in children and young adults with HIV. METHODS Subjects with HIV (age 8 to 24 yrs) were randomized to vitamin D3 supplementation of 4000 IU/day or 7000 IU/day and followed at 6 and 12 weeks for changes in 25D and whole blood lead concentration. This was a secondary analysis of a larger study of vitamin D3 supplementation in children and adolescents with HIV. RESULTS In 44 subjects (75% African American), the baseline mean ± SD serum 25D was 48.3 ± 18.6 nmol/L. 50% of subjects had baseline serum 25D 5.0 μg/dL at baseline or during subsequent visits. Whole blood lead and 25D were not correlated at baseline, and were negatively correlated after 12 weeks of supplementation (p= 0.014). Whole blood lead did not differ between those receiving 4000 IU versus 7000 IU of vitamin D3. CONCLUSION High dose vitamin D3 supplementation and the concomitant increased serum 25D did not result in increased whole blood lead concentration in this sample of children and young adults living in a northeastern urban city. PMID:23059649

  6. Toxic effects of lead on biochemical and histological alterations in green mussel (Perna viridis) induced by environmentally relevant concentrations.

    Science.gov (United States)

    Hariharan, G; Purvaja, R; Ramesh, R

    2014-01-01

    Acute and chronic toxicity tests were conducted on green mussel (Perna viridis) to determine the adverse effects of lead (Pb). Exposure of organisms to acute toxicity test for 96 h and lethal concentration (LC(50)) was the endpoint of the test. Acute toxicity for 96-h LC(50) and 95% confidence intervals of P. viridis was 2.62 ± 0.12 (2.62-3.24) mg/L Pb. Chronic toxicity tests revealed that survival of exposed organisms decreased with elevated exposure concentrations. No-observed-effect concentration (NOEC) and lowest-observed-effect concentration (LOEC) were calculated based on survival of test organisms. Results of this study demonstrated an increase in toxicity in test organisms with rise in exposure time and concentration. In this study, histology and biochemical enzymes, namely, catalase, reduced glutathione, glutathione S-transferase, and lipid peroxides, were correlated with chronic value and survival endpoints of P. viridis after chronic exposure to Pb. Biochemical and histological responses to different concentrations of Pb were assessed and significant differences were observed between control and increasing exposure concentrations. Biomarker studies in internal organs confirmed that the observed changes are due to adverse effects of Pb. This assessment of toxicity was the first step to determining the seawater quality criteria for marine organisms.

  7. High concentrations of NaCl induce cell swelling leading to senescence in human cells.

    Science.gov (United States)

    Yamakami, Yoshimi; Yonekura, Ryuzo; Matsumoto, Yuko; Takauji, Yuki; Miki, Kensuke; Fujii, Michihiko; Ayusawa, Dai

    2016-01-01

    Cell swelling and retardation in DNA replication are always observed in senescent cells. When DNA replication is slowed down with RNA and protein syntheses unchanged in proliferating cells, it causes a phenomenon known as unbalanced growth. The purpose of this study is to assess the role of cell swelling in unbalanced growth in terms of senescence and investigate the mechanism underlying this phenomenon. We tried to induce cell swelling with minimum damage to cells in this study. We perturbed the osmoregulatory functions to induce cell swelling under hypotonic and hypertonic conditions in normal human fibroblasts. Addition of excess NaCl was found to induce significant cell and nuclear swelling in dose- and time-dependent manners. Excess NaCl immediately retarded DNA replication, accumulated cells at G1 phase of the cell cycle, and eventually deprived division potential of the cells. Such cells showed typical senescent cell shape followed by expression of the typical senescence-associated genes. Excess NaCl also activated ERK1/2, p38, and JNK of the mitogen activated protein kinase family. Addition of U0126, an inhibitor of ERK1/2, prevented appearance of senescent features induced by excess NaCl. These results suggest that hypertonic conditions induce cell swelling due to unbalanced growth, thereby leading to cellular senescence.

  8. Effects of lead exposure on the concentration of cadmium, selenium and values of morphology in the blood

    Directory of Open Access Journals (Sweden)

    Agnieszka Kozłowska

    2015-06-01

    Full Text Available Introduction. Heavy metals, including cadmium and lead are both environmental and industrial toxins which cause metabolic disorders. Effects of these elements are long lasting and usually take a long time to show themselves. Also of importance is the active and passive exposure to tobacco smoke, which is also a source of heavy metals. Heavy metals exhibit nephrotoxic activity, hepatotoxic and neurotoxic, and mutagenic and carcinogenic activity. This study aimed to determine the relationship between occupational exposure to lead (Pb, cadmium (Cd and the level of selenium (Se, and values of morphology of employees of zinc and lead smelter. Material and methods. 334 occupationally exposed males (tested group and 60 males not exposed (control group were involved in the study. The men were between 19 and 62 years of age. The study population lived and/or worked in the industrial region of Upper Silesia. Blood cadmium concentration (Cd-B, blood lead concentration (Pb-B and serum concentrations of Se (Se-S were studied. The level of elements was determined by flameless atomic absorption spectrometry. Results. The average concentration of each metal in the exposed group was 2.42±2.20 µg/l (Cd-B, 33±9.6 µg/dl (Pb-B and 73.99±20.44 µg/l (Se-S. In the entire study population (exposed and control, a statistically significant negative linear relationship was found between Pb-B and Se-S (r=–0.16, p<0.05. There was no correlation between Cd-B and Se-S, whereas a statistically significant positive correlation was observed between Pb-B and Cd-B (r=0.48, p<0.05. Spearman Rank Correlation analysis showed that in the study population there was observed statistically significant (p<0.05 negative correlation between Se-S in smokers group. Conclusions. Higher concentrations of Cd and Pb were observed in the exposed group compared to the control group. Occupational exposure to cadmium and lead may be a factor lowering the blood Se in the tested group. The most

  9. Total lead (Pb) concentration in oil shale ash samples based on correlation to isotope Pb-210 gamma-spectrometric measurements

    Energy Technology Data Exchange (ETDEWEB)

    Vaasma, T.; Kiisk, M.; Tkaczyk, A.H. [University of Tartu (Estonia); Bitjukova, L. [Tallinn University of Technology (Estonia)

    2014-07-01

    Estonian oil shale consists of organic matter and mineral material and contains various amounts of heavy metals as well as natural radionuclides (from the U-238 and Th-232 series and K-40). Previous research has shown that burning oil shale in the large power plants causes these radionuclides to become enriched in different ash fractions and be partially emitted to the atmosphere via fly ash and flue gases. The activity concentrations (Bq/kg) of these nuclides in different oil shale ash fractions vary significantly. This is influenced by the boiler parameters and combustion conditions - prevailing temperatures, pressure, ash circulating mechanisms, fly ash particle size, chemical composition of ash and coexistence of macro and micro components. As with radionuclides, various heavy metals remain concentrated in the ash fractions and are released to the atmosphere (over 20 tons of Pb per year from Estonian oil shale power plants). Lead is a heavy metal with toxic influence on the nervous system, reproductive system and different organs in human body. Depending on the exposure pathways, lead could pose a long term health hazard. Ash samples are highly heterogeneous and exhibit great variability in composition and particle size. Determining the lead concentration in ash samples by modern methods like inductively coupled plasma mass spectroscopy (ICP-MS), flame atomic absorption spectrometry (FAAS), graphite furnace atomic absorption spectroscopy (GFAAS) and other techniques often requires time consuming, multistage and complex chemical sample preparation. The list of possible methods to use is lengthy, but it is a challenge to choose a suitable one to meet measurement needs and practical considerations. The detection limits, capital costs and maintenance expenses vary between the instruments. This work presents the development of an alternative measurement technique for our oil shale ash samples. Oil shale ash was collected from different boilers using pulverized fuel

  10. Concentrations of strontium, barium, cadmium, copper, zinc, manganese, chromium, antimony, selenium and lead in the equine liver and kidneys.

    Science.gov (United States)

    Paßlack, Nadine; Mainzer, Barbara; Lahrssen-Wiederholt, Monika; Schafft, Helmut; Palavinskas, Richard; Breithaupt, Angele; Neumann, Konrad; Zentek, Jürgen

    2014-01-01

    The concentrations of specific elements in the equine liver and kidneys are of practical relevance since horses are not only food-producing animals, but also partially serve as an indicator for the environmental pollution, as the basic feed includes plants like grass, grain and fruits. In this study, the concentrations of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se) and lead (Pb) were measured in the liver, renal cortex and renal medulla of 21 horses (8 male; 13 female; aged between 5 months-28 years), using inductively coupled plasma mass spectrometry. Comparable Cu and Zn concentrations were detected in the liver and renal cortex, while approximately 50% lower concentrations were measured in the renal medulla. The lowest Sr, Cd and Se, but the highest Mn, Sb and Pb concentrations were measured in the liver. The Ba concentrations were comparable in the renal cortex and medulla, but lower in the liver of the horses. Gender-related differences were observed for Cd, Mn and Cr, with higher Cd concentrations in the liver, but lower Mn concentrations in the renal cortex and lower Cr concentrations in the renal medulla of female horses. Age-related differences were detected for most measured elements, however, the animal number per age-group was only low. In conclusion, the present study provides important reference data for the storage of Sr, Ba, Cd, Cu, Zn, Mn, Cr, Sb, Se and Pb in the liver and kidneys of horses, which are of practical relevance for an evaluation of the exposure of horses to these elements, either via feed or the environment.

  11. Environmental tobacco smoke (ETS) exposure in children with asthma-relation between lead and cadmium, and cotinine concentrations in urine.

    Science.gov (United States)

    Willers, Stefan; Gerhardsson, Lars; Lundh, Thomas

    2005-12-01

    Exposure to heavy metals from environmental tobacco smoke (ETS) was investigated in 23 children with asthma (8.4+/-3.7 yr). ETS exposure was assessed by an inquiry data-based exposure index, the urinary concentration of cotinine (U-cotinine; a major nicotine metabolite) and the house dust (fine and coarse fractions) concentrations of nicotine at home. The corresponding concentrations of the heavy metals cadmium and lead in dust and urine (U-Cd; U-Pb) were determined in the same samples. There were strong associations between the ETS exposure index and U-cotinine (r(s)=0.62; Plead and cadmium concentrations in both fine (r(s)=0.86; Plead concentrations in fine dust (r(s)=0.52; P=0.06), no other significant associations were found between house dust metals and nicotine concentrations. U-Cd correlated well with U-cotinine (r(s)=0.50; P=0.02). Further, U-Pb were associated with U-cotinine, however not statistically significant (r(s)=0.41; P=0.06). A probable explanation is a direct inhalation of side-stream smoke containing heavy metals and/ or an increased pulmonary uptake, due to a small airways disease in children with asthma.

  12. Concentration of copper, iron, zinc, cadmium, lead, and nickel in boar semen and relation to the spermatozoa quality.

    Science.gov (United States)

    Massányi, Peter; Trandzík, Jozef; Nad, Pavol; Koréneková, Beáta; Skalická, Magdaléna; Toman, Robert; Lukác, Norbert; Strapák, Peter; Halo, Marko; Turcan, Ján

    2003-01-01

    The concentration of copper, iron, zinc, cadmium, lead, and nickel as well as its relation to spermatozoa quality was investigated. The semen samples were analyzed by atomic absorption spectrophotometry (AAS). The concentration of copper in boar semen was 1.64 +/- 0.28 mg kg(-1) and of iron 16.14 +/- 10.35 mg kg(-1). The concentration of zinc in boar semen reached an average value of 171.74 +/- 64.72 mg kg(-1) and the level of cadmium reached 0.01-0.16 mg kg(-1) with the average value of 0.05 mg kg(-1). The analysis of lead showed that the concentration of this element in boar semen was 0.02 +/- 0.03 mg kg(-1) and the average level of nickel was 0.06 +/- 0.08 mg kg(-1). The total percentage of pathological spermatozoa was 9.82 +/- 1.47%. Detail analysis determined 3.18% of separated flagellum, 2.26% knob twisted flagellum, 0.88% flagellum torso, 0.85% flagellum ball, 0.42% broken flagellum, 0.23% retention of the cytoplasmic drop, 0.14% small heads, 0.03% large heads, and 1.83% forms other of pathological changes. Correlation analysis showed significant (p spermatozoa (r = 0.73) was determined.

  13. Exposure of young children to household water lead in the Montreal area (Canada): the potential influence of winter-to-summer changes in water lead levels on children's blood lead concentration.

    Science.gov (United States)

    Ngueta, G; Prévost, M; Deshommes, E; Abdous, B; Gauvin, D; Levallois, P

    2014-12-01

    Drinking water represents a potential source of lead exposure. The purpose of the present study was to estimate the magnitude of winter-to-summer changes in household water lead levels (WLLs), and to predict the impact of these variations on BLLs in young children. A study was conducted from September, 2009 to March, 2010 in 305 homes, with a follow-up survey carried out from June to September 2011 in a subsample of 100 homes randomly selected. The first 1-L sample was drawn after 5 min of flushing, followed by a further 4 consecutive 1-L samples after 30 min of stagnation. Non-linear regression and general linear mixed models were used for modelling seasonal effects on WLL. The batchrun mode of Integrated Exposure Uptake Biokinetic (IEUBK) model was used to predict the impact of changes in WLL on children's blood lead levels (BLLs). The magnitude of winter-to-summer changes in average concentrations of lead corresponded to 6.55 μg/L in homes served by lead service lines (LSL+ homes) and merely 0.30 μg/L in homes without lead service lines. For stagnant samples, the value reached 10.55 μg/L in 'LSL+ homes' and remained very low (0.36 μg/L) in 'LSL- homes'. The change in the probability of BLLs ≥5 μg/dL due to winter-to-summer changes in WLL was increased from water.

  14. Determination of lead, cations, and anions concentration in indoor and outdoor air at the primary schools in Kuala Lumpur.

    Science.gov (United States)

    Awang, Normah; Jamaluddin, Farhana

    2014-01-01

    This study was carried out to determine the concentration of lead (Pb), anions, and cations at six primary schools located around Kuala Lumpur. Low volume sampler (MiniVol PM10) was used to collect the suspended particulates in indoor and outdoor air. Results showed that the concentration of Pb in indoor air was in the range of 5.18 ± 1.08 μg/g-7.01 ± 0.08 μg/g. All the concentrations of Pb in indoor air were higher than in outdoor air at all sampling stations. The concentrations of cations and anions were higher in outdoor air than in indoor air. The concentration of Ca(2+) (39.51 ± 5.01 mg/g-65.13 ± 9.42 mg/g) was the highest because the cation existed naturally in soil dusts, while the concentrations of NO3 (-) and SO4 (2-) were higher in outdoor air because there were more sources of exposure for anions in outdoor air, such as highly congested traffic and motor vehicles emissions. In comparison, the concentration of NO3 (-) (29.72 ± 0.31 μg/g-32.00 ± 0.75 μg/g) was slightly higher than SO4 (2-). The concentrations of most of the parameters in this study, such as Mg(2+), Ca(2+), NO3 (-), SO4 (2-), and Pb(2+), were higher in outdoor air than in indoor air at all sampling stations.

  15. Crystalline texture and mammography energy range detection studies of pyrolysed lead iodide films: Effects of solution concentration

    Energy Technology Data Exchange (ETDEWEB)

    Condeles, J.F., E-mail: condeles@fisica.uftm.edu.br [Department of Physics, Institute of Exact Sciences, Naturals and Education, Federal Universty of Triângulo Mineiro, 38064-200, Uberaba, MG (Brazil); Mulato, M. [Department of Physics, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Av. Bandeirantes 3900, 14040-901, Ribeirão Preto, SP (Brazil)

    2015-09-15

    Semiconductor lead iodide (PbI{sub 2}) films have been extensively studied due to their potential applications in room temperature ionizing radiation detectors. The influence of PbI{sub 2} solution concentration on the final properties of the films grown by spray pyrolysis was investigated. The solution concentration was varied in the range of 10 g/l up to 50 g/l. Total deposition time of 2.5 h was used and average growth rate varying from 22 Å s{sup −1} up to 62 Å s{sup −1} was obtained as a function of solution concentration. X-ray diffraction was used to investigate the structural properties of the films. Variations in microstructure as a function of solution concentration were studied using crystal texture calculations. The smallest value of electrical resistivity was obtained for the largest solution concentration. Mammographic X-ray irradiation from 10 mR up to 1450 mR was carried out with equivalent photon energy at 14 keV and the sensor results are discussed. - Highlights: • PbI{sub 2} films were grown by spray pyrolysis deposition method. • Variations in microstructure were studied using crystal texture calculations. • The films were tested in the mammography X-ray energy range. • The response is very linear with a slope of 13 μA/cm{sup 2} R.

  16. Lead, zinc, and chromium concentrations in acidic headwater streams in Sweden explained by chemical, climatic, and land-use variations

    Directory of Open Access Journals (Sweden)

    B. J. Huser

    2012-11-01

    Full Text Available Long-term data series (1996–2009 for eleven acidic headwater streams (< 10 km2 in Sweden were analyzed to determine factors controlling concentrations of trace metals. In-stream chemical data as well climatic, flow, and deposition chemistry data were used to develop models predicting concentrations of chromium (Cr, lead (Pb, and zinc (Zn. Data were initially analyzed using partial least squares to determine a set of variables that could predict metal concentrations across all sites. Organic matter (as absorbance and iron related positively to Pb and Cr, while pH related negatively to Pb and Zn. Other variables such as conductivity, manganese, and temperature were important as well. Multiple linear regression was then used to determine minimally adequate prediction models which explained an average of 35% (Cr, 52% (Zn, and 72% (Pb of metal variation across all sites. While models explained at least 50% of variation in the majority of sites for Pb (10 and Zn (8, only three sites met this criterion for Cr. Investigation of variation between site models for each metal revealed geographical (altitude, chemical (sulfate, and land-use (silvaculture influences on predictive power of the models. Residual analysis revealed seasonal differences in the ability of the models to predict metal concentrations as well. Expected future changes in model variables were applied and results showed the potential for long-term increases (Pb or decreases (Zn for trace metal concentrations at these sites.

  17. Nitrogen dioxide reducing ascorbic acid technologies in the ventilator circuit leads to uniform NO concentration during inspiration.

    Science.gov (United States)

    Pezone, Matthew J; Wakim, Matthew G; Denton, Ryan J; Gamero, Lucas G; Roscigno, Robert F; Gilbert, Richard J; Lovich, Mark A

    2016-08-31

    Conventional inhaled NO systems deliver NO by synchronized injection or continuous NO flow in the ventilator circuitry. Such methods can lead to variable concentrations during inspiration that may differ from desired dosing. NO concentrations in these systems are generally monitored through electrochemical methods that are too slow to capture this nuance and potential dosing error. A novel technology that reduces NO2 into NO via low-resistance ascorbic-acid cartridges just prior to inhalation has recently been described. The gas volume of these cartridges may enhance gas mixing and reduce dosing inconsistency throughout inhalation. The impact of the ascorbic-acid cartridge technology on NO concentration during inspiration was characterized through rapid chemiluminescence detection during volume control ventilation, pressure control ventilation, synchronized intermittent mandatory ventilation and continuous positive airway pressure using an in vitro lung model configured to simulate the complete uptake of NO. Two ascorbic acid cartridges in series provided uniform and consistent dosing during inspiration during all modes of ventilation. The use of one cartridge showed variable inspiratory concentration of NO at the largest tidal volumes, whereas the use of no ascorbic acid cartridge led to highly inconsistent NO inspiratory waveforms. The use of ascorbic acid cartridges also decreased breath-to-breath variation in SIMV and CPAP ventilation. The ascorbic-acid cartridges, which are designed to convert NO2 (either as substrate or resulting from NO oxidation during injection) into NO, also provide the benefit of minimizing the variation of inhaled NO concentration during inspiration. It is expected that the implementation of this method will lead to more consistent and predictable dosing.

  18. Geostatistical study of spatial correlations of lead and zinc concentration in urban reservoir. Study case Czerniakowskie Lake, Warsaw, Poland

    Science.gov (United States)

    Fabijańczyk, Piotr; Zawadzki, Jarosław; Wojtkowska, Małgorzata

    2016-07-01

    The article presents detailed geostatistical analysis of spatial distribution of lead and zinc concentration in water, suspension and bottom sediments of large, urban lake exposed to intensive anthropogenic pressure within a large city. Systematic chemical measurements were performed at eleven cross-sections located along Czerniakowskie Lake, the largest lake in Warsaw, the capital of Poland. During the summer, the lake is used as a public bathing area, therefore, to better evaluate human impacts, field measurements were carried out in high-use seasons. It was found that the spatial distributions of aqueous lead and zinc differ during the summer and autumn. In summer several Pb and Zn hot-spots were observed, while during autumn spatial distributions of Pb and Zn were rather homogenous throughout the entire lake. Large seasonal differences in spatial distributions of Pb and Zn were found in bottom sediments. Autumn concentrations of both heavy metals were ten times higher in comparison with summer values. Clear cross-correlations of Pb and Zn concentrations in water, suspension and bottom sediments suggest that both Pb and Zn came to Czerniakowskie Lake from the same source.

  19. Nanomolar concentrations of inorganic lead increase Ca2+ efflux and decrease intracellular free Ca2+ ion concentrations in cultured rat hippocampal neurons by a calmodulin-dependent mechanism.

    Science.gov (United States)

    Ferguson, C; Kern, M; Audesirk, G

    2000-06-01

    Inorganic lead (Pb2+) activates calmodulin, which in turn may stimulate many other cellular processes. The plasma membrane Ca2+ ATPase is a calmodulin-stimulated enzyme that plays the major role in regulating the "resting" intracellular free Ca2+ ion concentration, [Ca2+]i. We hypothesized that exposing neurons to low levels of Pb2+ would cause Pb2+ to enter the cytoplasm, and that intracellular Pb2+, by activating calmodulin, would stimulate plasma membrane Ca2+ ATPase activity, thereby increasing Ca2+ extrusion and reducing [Ca2+]i. We used the ratiometric Ca2+ indicator fura-2 to estimate changes in [Ca2+]i. In vitro calibrations of fura-2 with solutions of defined free Ca2+ and free Pb2+ concentrations showed that, at free Ca2+ concentrations from 10 nM to 1000 nM, adding Pb2+ caused either no significant change in the F340/F380 ratio (free Pb2+ concentrations from 100 fM to 1 pM) or increased the F340/F380 ratio (free Pb2+ concentrations from 5 to 50 pM). Therefore, fura-2 should be suitable for estimating Pb2+-induced decreases in [Ca2+]i, but not increases in [Ca2+]i. We exposed cultured embryonic rat hippocampal neurons to 100 nM Pb2+ for periods from 1 hour to 2 days and measured the F340/F380 ratio; the ratio decreased significantly by 9 to 16% at all time points, indicating that Pb2+ exposure decreased [Ca2+]i. In neurons loaded with 45Ca, Pb2+ exposure increased Ca2+ efflux for at least two hours; by 24 hours, Ca2+ efflux returned to control levels. Influx of 45Ca was not altered by Pb2+ exposure. Low concentrations (250 nM) of the calmodulin inhibitor calmidazolium had no effect on either 45Ca efflux or on the F340/F380 ratio in fura-loaded control neurons, but completely eliminated the increase in 45Ca efflux and decrease in F340/F380 ratio in Pb2+-exposed neurons. Zaldoride, another calmodulin inhibitor, also eliminated the decrease in F340/F380 ratio in Pb2+-exposed neurons. We conclude that Pb2+ exposure decreases [Ca2+]i and increases Ca2+ efflux

  20. Correlation Between the Concentration of Lead in the Blood of Dogs and People Living in the Same Environmental Conditions

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    Monkiewicz Jerzy

    2014-10-01

    Full Text Available The studies, conducted between 2010 and 2012, involved 102 dogs and 505 people from Lower Silesia (LS, 104 dogs and 578 people from the Legnica - Głogów Copper Mining Region (LGCMR, and 101 dogs and 897 people from the Upper Silesian Industrial Region (USIR. A significant positive correlation between blood lead concentration (BLC in dogs and people living in the same environment was found. Moreover, the data revealed an increase in BLC in dogs and people with the progressive aging of the body. The highest average BLC in dogs and humans were reported in the LGCMR followed by USIR and LS.

  1. Significant interaction between activated charcoal and antiretroviral therapy leading to subtherapeutic drug concentrations, virological breakthrough and development of resistance.

    Science.gov (United States)

    Tseng, Alice L; la Porte, Charles; Salit, Irving E

    2013-01-01

    A 42-year-old, treatment-experienced woman, virologically suppressed on tenofovir/emtricitabine and boosted atazanavir, experienced virological breakthrough, drop in CD4(+) T-cell count and undetectable drug concentrations. Adherence to treatment was confirmed, but repeat testing yielded similar results. After 2 months, the patient stated that she had been taking activated charcoal to manage gastrointestinal symptoms associated with her combination antiretroviral therapy, but she had recently discontinued the charcoal. Atazanavir concentrations were therapeutic but the patient's viral load rebounded and genotype testing revealed new reverse transcriptase mutations. The patient was changed to zidovudine, lamivudine, and boosted darunavir and achieved viral suppression. At 1 year follow-up, her viral load remained activated charcoal and atazanavir/ritonavir leading to virological breakthrough and development of resistance.

  2. Historical changes in lead concentrations in tree-rings of sycamore, oak and Scots pine in north-west England.

    Science.gov (United States)

    Watmough, Shaun A; Hutchinson, Thomas C

    2002-07-01

    Lead concentrations in tree rings of sycamore (Acer pseudoplatanus L.), oak (Quercus robur L.) and Scots pine (Pinus sylvestris L.) sampled at a parkland in north-west England were measured in wood formed since the mid-1800s. Concentrations of Pb in Scots pine and oak peaked in wood formed between 1900 and 1940, most likely because of Pb accumulation in heartwood, indicating that oak and Scots pine are unsuitable for monitoring temporal changes in Pb deposition at the study site. In contrast, Pb concentrations in sycamore, a species that has similar heartwood and sapwood chemistry, were relatively constant in wood formed between the mid-1800s and 1950. Lead concentrations decreased steadily in sycamore tree rings formed after the 1950s, and decreased more abruptly in wood formed after 1985. This sharp decrease in wood Pb cannot be due to decreases in soil Pb concentration. Stable Pb isotope analysis was used to further investigate Pb patterns in sycamore wood. Excess 206Pb/207Pb ratios in tree-rings of sycamore were relatively constant, approximately 1.17, in wood formed prior to the 1930s, but decreased steadily thereafter reaching a minimum value of approximately 1.16 in wood formed between 1975 and 1985 after which time 206Pb/207Pb ratios increased. This pattern is consistent with changes in Pb isotope ratios measured in peat, sediment and aerosol samples in the UK. However, the magnitude of the decrease in 206Pb/207Pb (largely due to gasoline Pb) is considerably lower than in other studies and our estimates indicate that less than 20% of the total Pb in sycamore wood measured since the mid-1800s is derived from gasoline emissions. A more likely explanation for the pattern of Pb observed in sycamore tree rings is that soil Pb accumulates within rings of the diffuse porous wood over a number of years. Such uptake patterns would result in lower Pb concentrations in the outer (more recently formed) tree rings, which coincide with recent reductions in Pb deposition

  3. A comparison of portable XRF and ICP-OES analysis for lead on air filter samples from a lead ore concentrator mill and a lead-acid battery recycler.

    Science.gov (United States)

    Harper, Martin; Pacolay, Bruce; Hintz, Patrick; Andrew, Michael E

    2006-03-01

    Personal and area samples for airborne lead were taken at a lead mine concentrator mill, and at a lead-acid battery recycler. Lead is mined as its sulfidic ore, galena, which is often associated with zinc and silver. The ore typically is concentrated, and partially separated, on site by crushing and differential froth flotation of the ore minerals before being sent to a primary smelter. Besides lead, zinc and iron are also present in the airborne dusts, together with insignificant levels of copper and silver, and, in one area, manganese. The disposal of used lead-acid batteries presents environmental issues, and is also a waste of recoverable materials. Recycling operations allow for the recovery of lead, which can then be sold back to battery manufacturers to form a closed loop. At the recycling facility lead is the chief airborne metal, together with minor antimony and tin, but several other metals are generally present in much smaller quantities, including copper, chromium, manganese and cadmium. Samplers used in these studies included the closed-face 37 mm filter cassette (the current US standard method for lead sampling), the 37 mm GSP or "cone" sampler, the 25 mm Institute of Occupational Medicine (IOM) inhalable sampler, the 25 mm Button sampler, and the open-face 25 mm cassette. Mixed cellulose-ester filters were used in all samplers. The filters were analyzed after sampling for their content of the various metals, particularly lead, that could be analyzed by the specific portable X-ray fluorescence (XRF) analyzer under study, and then were extracted with acid and analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The 25 mm filters were analyzed using a single XRF reading, while three readings on different parts of the filter were taken from the 37 mm filters. For lead at the mine concentrate mill, all five samplers gave good correlations (r2 > 0.96) between the two analytical methods over the entire range of found lead mass

  4. Lead and cadmium in human teeth from Jordan by atomic absorption spectrometry: Some factors influencing their concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Alomary, A. [Department of Chemistry, Yarmouk University, Irbid (Jordan)]. E-mail: ahmedalomary1000@hotmail.com; Al-Momani, I.F. [Department of Chemistry, Yarmouk University, Irbid (Jordan); Massadeh, A.M. [Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid (Jordan)

    2006-10-01

    The aim of this study was to measure the concentrations of lead (Pb) and cadmium (Cd) in human teeth and to investigate the affecting factors. Teeth samples (n = 268) were collected from people living in different cities in Jordan including Amman, Zarqa, Al-Mafraq and Irbid and analyzed for Pb and Cd using atomic absorption spectrometry (AAS). A questionnaire was used to gather information on each person, such as age, sex, place where the patient lives, smoking, presence of amalgam fillings inside the mouth, and whether the patient uses toothpaste or not. The mean concentrations of Pb and Cd were 28.91 {mu}g/g and 0.44 {mu}g/g, respectively. The results indicate that there is a clear relation between Pb and Cd concentrations and the presence of amalgam fillings, smoking, and place of living. Pb was sex-dependent, whereas Cd was not. Our results show that Pb and Cd concentrations in samples obtained from Al-Mafraq and Irbid are higher than those obtained from Amman and Zarqa. Pb was highest in Mafraq, whereas Cd was highest in Irbid. The Pb and Cd concentrations in teeth from smokers (means: Pb = 31.89 {mu}g/g, Cd = 0.49 {mu}g/g) were significantly higher than those from nonsmokers (means: Pb = 24.07 {mu}g/g, Cd = 0.37 {mu}g/g). Pb and Cd concentrations in teeth of patients with amalgam fillings (means: Pb = 31.02 {mu}g/g and Cd = 0.52 {mu}g/g) were significantly higher than those from patients without amalgam fillings (means: Pb = 26.87 {mu}g/g and Cd = 0.41 {mu}g/g). Our results show that brushing the teeth daily with toothpaste does not significantly decrease the concentration of both Pb and Cd. The mean concentrations of Pb and Cd do not vary significantly between the ages 20-30, 31-40, and 41-50, but both increased rapidly at age 51-60.

  5. Concentration of lead, cadmium, and mercury in tissues of European beaver (Castor fiber from the north-eastern Poland

    Directory of Open Access Journals (Sweden)

    Giżejewska Aleksandra

    2014-03-01

    Full Text Available The aim of the study was to determine the concentrations of lead (Pb, cadmium (Cd, and mercury (Hg in the liver, kidneys, and muscles of European beavers (Castor fiber and thus to evaluate the degree of heavy metals contamination in Warmia and Mazury region in Poland. The study was conducted on free-living beavers captured in region of Warmia and Mazury during autumn 2011. Concentrations of the elements were determined by atomic absorption spectrometry. The presence of the metals was detected in all individual tissue samples. Mean Pb and Hg concentrations were relatively low. However, the high mean Cd level, especially in the kidneys (7.933 mg/kg and liver (0.880 mg/kg was demonstrated. Despite the fact that region of Warmia and Mazury is considered to be “ecologically clean”, the conducted studies indicate that systematic monitoring for the presence of heavy metals is necessary not only in industrialised but also in agricultural regions, as well as in natural ecosystems.

  6. Lead concentrations in sediments and blue-winged teals (Anas discors) from El Palmar State Reserve, Yucatan, Mexico.

    Science.gov (United States)

    Adán, Echeverría-García; Gerardo, Gold-Bouchot

    2013-10-01

    Reserve regulations at El Palmar State Reserve, Yucatan, Mexico, prohibit the use of lead (Pb) shot, but hunters continue to use it, and no enforcement is implemented. Pb was quantified in sediments and in blue-winged teal Anas discors. No shot pellets were found in the sediment samples, nor were differences in sediment Pb concentrations observed within the reserve between popular hunting sites and those no longer used for hunting. However, there were differences between the hunting sites and sediments from an adjacent area where hunting is prohibited. Average Pb concentrations were highest at hunting entrances (15.69 ± 18.69 mg/kg) and lowest at decoy locations (5.24 ± 4.84 mg/kg). These averages are lower than the lowest effects level (31 mg/kg), although 10 samples exceeded this level. Pb-shot prevalence in gizzards was 4.88% (n = 41). Pb levels exceeded 5.0 mg/kg dry weight in one or more of the tested tissues (liver, gizzard, and bone) in 14 (34.14%; 7 female, 7 male; 11 adult, 3 juvenile) of the total birds. Bird weight, sex, and age had no effect on Pb concentration. Hunting using Pb shot in the reserve clearly affects Pb levels in sediments and in A. discors that winter there.

  7. Lead Concentrations in Raw Cow and Goat Milk Collected in Rural Areas of Croatia from 2010 to 2014.

    Science.gov (United States)

    Bilandžić, Nina; Sedak, Marija; Čalopek, Bruno; Luburić, Đurđica Božić; Solomun Kolanović, Božica; Varenina, Ivana; Đokić, Maja; Kmetič, Ivana; Murati, Teuta

    2016-05-01

    A total of 249 cow and 33 goat milk samples were collected in rural areas of Croatia during the period 2010-2014. Lead concentrations in milk samples were analyzed by graphite furnace-atomic absorption spectroscopy. Mean Pb concentrations in milk ranged from (μg/kg): cow 10.8-12.2; goat 9.33-60.0. The highest Pb level of 131 μg/kg in cow milk was measured during 2014. There were no significant differences in Pb levels between cow and goat milk and also in goat milk among the analysed years. However, significant differences were found in cow milk among years. The highest Pb was determined in 2011 (157 μg/kg in goat milk). The calculated estimated weekly intakes of Pb concentrations for cow and goat milk contribute only 1.37 % and 1.84 % to the provisional tolerable weekly intake. Therefore, the consumption of milk from both species should not pose a consumer health risk.

  8. Spatial Distribution of Lead Isotope Ratios and Inorganic Element Concentrations in Epiphytic Lichens from the Athabasca Oil Sands Region

    Science.gov (United States)

    Graney, J. R.; Landis, M. S.; Puckett, K.; Edgerton, E.; Krupa, S.; Percy, K.

    2013-12-01

    Coupled studies of inorganic element concentrations and lead (Pb) isotope ratios have been conducted on Hypogymnia physodes samples collected in the Athabasca Oil Sands Region (AOSR) in Alberta, Canada in 2002, 2008, and 2011. To investigate the spatial extent of air emissions, the lichens were collected from sites as far as 160 km from the mining and processing operations. 30 milligram sub-samples of the lichens were microwave digested, and the extracts were analyzed using DRC-ICPMS to determine elemental concentrations, and sector field ICPMS to measure Pb isotope ratios. Concentrations of elements in the lichens were found to reflect proximity to mining and oil processing sites as well as topography, ecosystem differences, and the metabolic biogeochemistry of the lichens. An exponential decrease in concentration of metals associated with fugitive dust (aluminum and others) versus distance from the mining sites, suggests elevated coarse particle emissions associated with mining operations. Near source concentrations of metals with an oil signature (vanadium and others) are less enhanced and more homogeneous than the metals in the fugitive dust, reflecting emission and deposition of smaller diameter particles at greater distances from oil processing sources. The mining and oil processing signatures are superimposed over elemental concentrations that reflect the nutrient needs of the lichens. These findings are being confirmed through ongoing studies using dichot samplers to collect coarse and fine particulate aerosol samples. The lichen samples collected beyond 50 km from the mining and processing sites cluster into a Pb isotope grouping with a 207Pb / 206Pb ratio of 0.8650 and a 208Pb / 206Pb ratio near 2.095. This grouping likely reflects the regional background Pb isotope ratio signature. 207Pb / 206Pb and 208Pb / 206Pb ratios decrease as one nears the mining and processing operations. This indicates that other Pb source(s), (e.g. Pb in the bitumen from the oil

  9. Concentrations and health risks of lead, cadmium, arsenic, and mercury in rice and edible mushrooms in China.

    Science.gov (United States)

    Fang, Yong; Sun, Xinyang; Yang, Wenjian; Ma, Ning; Xin, Zhihong; Fu, Jin; Liu, Xiaochang; Liu, Meng; Mariga, Alfred Mugambi; Zhu, Xuefeng; Hu, Qiuhui

    2014-03-15

    In this study, four common heavy metals, lead (Pb), cadmium (Cd), arsenic (As) and mercury (Hg) in rice and edible mushrooms of China were studied to evaluate contamination level and edible safety. Ninety two (92) rice samples were collected from the main rice growing regions in China, and 38 fresh and 21 dry edible mushroom samples were collected from typical markets in Nanjing City. The analyzed metal concentrations were significantly different between rice and edible mushroom samples (pmushroom, Pb and Hg contents in 2.6% samples were above MAC, respectively. However, only Hg content in 4.8% dry edible mushroom samples was above its MAC. Therefore, more than 95% rice and edible mushroom samples in our test had high edible safety.

  10. Evidence that cognitive deficit in children is associated not only with iron deficiency, but also with blood lead concentration: a preliminary study.

    Science.gov (United States)

    Jeong, Kyoung Sook; Park, Hyewon; Ha, Eunhee; Hong, Yun-Chul; Ha, Mina; Park, Hyesook; Kim, Bung-Nyun; Lee, Soo-Jeong; Lee, Kyung Yeon; Kim, Ja Hyeong; Kim, Yangho

    2015-01-01

    To investigate whether blood lead concentrations are elevated in iron-deficient children, and to examine the association between iron deficiency and/or elevated blood lead concentration and cognitive deficits in children. The present study is a component of the Mothers' and Children's Environmental Health (MOCEH) study, a multi-center birth cohort project in Korea that began in 2006. The study cohort consisted of 194 children who underwent testing of blood lead and serum C-reactive proteins (CRPs) and ferritin concentrations, and the Korean version of the Wechsler Preschool and Primary Scale of Intelligence, revised edition (WPPSI-R), at 60 months of age. In addition, the mothers' blood lead concentrations during pregnancy were included in the analyses. Multivariate linear regression analysis was performed to analyze the correlation between high blood lead and low serum ferritin concentrations, after adjustment for covariates, in children, as well as to analyze the association of verbal IQ with serum ferritin and blood lead concentrations. Lead and ferritin concentrations were inversely and significantly associated in children after adjustment for covariates. Moreover, both concentrations were associated with verbal IQ, after adjustment for covariates, and each was associated with cognitive deficits after adjustment for the other. Sobel test statistics showed that blood lead concentration was a significant partial mediator for the relationship between iron deficiency and verbal IQ. Due to the results discussed in the present study, cognitive deficit in children seems to be associated not only with iron deficiency, but also with blood lead concentration. Copyright © 2014 Elsevier GmbH. All rights reserved.

  11. Elevated Concentrations of Lead in Particulate Matter on the Neighborhood-Scale in Delhi, India As Determined by Single Particle Analysis.

    Science.gov (United States)

    Shen, Hongru; Peters, Thomas M; Casuccio, Gary S; Lersch, Traci L; West, Roger R; Kumar, Amit; Kumar, Naresh; Ault, Andrew P

    2016-05-17

    High mass concentrations of atmospheric lead particles are frequently observed in the Delhi, India metropolitan area, although the sources of lead particles are poorly understood. In this study, particles sampled across Delhi (August - December 2008) were analyzed by computer-controlled scanning electron microscopy with energy dispersive X-ray spectroscopy (CCSEM-EDX) to improve our understanding of the spatial and physicochemical variability of lead-rich particles (>90% lead). The mean mass concentration of lead-rich particles smaller than 10 μm (PM10) was 0.7 μg/m(3) (1.5 μg/m(3) std. dev.) with high variability (range: 0-6.2 μg/m(3)). Four samples (16% of 25 samples) with PM10 lead-rich particle concentrations >1.4 μg/m(3) were defined as lead events and studied further. The temporal characteristics, heterogeneous spatial distribution, and wind patterns of events, excluded regional monsoon conditions or common anthropogenic sources from being the major causes of the lead events. Individual particle composition, size, and morphology analysis indicate informal recycling operations of used lead-acid batteries as the likely source of the lead events. This source is not typically included in emission inventories, and the observed isolated hotspots with high lead concentrations could represent an elevated exposure risk in certain neighborhoods of Delhi.

  12. Stimulation of TRPC5 cationic channels by low micromolar concentrations of lead ions (Pb{sup 2+})

    Energy Technology Data Exchange (ETDEWEB)

    Sukumar, Piruthivi [Multidisciplinary Cardiovascular Research Centre and Institute of Membrane and Systems Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT (United Kingdom); Beech, David J., E-mail: d.j.beech@leeds.ac.uk [Multidisciplinary Cardiovascular Research Centre and Institute of Membrane and Systems Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2010-02-26

    Lead toxicity is long-recognised but continues to be a major public health problem. Its effects are wide-ranging and include induction of hyper-anxiety states. In general it is thought to act by interfering with Ca{sup 2+} signalling but specific targets are not clearly identified. Transient receptor potential canonical 5 (TRPC5) is a Ca{sup 2+}-permeable ion channel that is linked positively to innate fear responses and unusual amongst ion channels in being stimulated by trivalent lanthanides, which include gadolinium. Here we show investigation of the effect of lead, which is a divalent ion (Pb{sup 2+}). Intracellular Ca{sup 2+} and whole-cell patch-clamp recordings were performed on HEK 293 cells conditionally over-expressing TRPC5 or other TRP channels. Extracellular application of Pb{sup 2+} stimulated TRPC5 at concentrations greater than 1 {mu}M. Control cells without TRPC5 showed little or no response to Pb{sup 2+} and expression of other TRP channels (TRPM2 or TRPM3) revealed partial inhibition by 10 {mu}M Pb{sup 2+}. The stimulatory effect on TRPC5 depended on an extracellular residue (E543) near the ion pore: similar to gadolinium action, E543Q TRPC5 was resistant to Pb{sup 2+} but showed normal stimulation by the receptor agonist sphingosine-1-phosphate. The study shows that Pb{sup 2+} is a relatively potent stimulator of the TRPC5 channel, generating the hypothesis that a function of the channel is to sense metal ion poisoning.

  13. Arsenic, iron, lead, manganese, and uranium concentrations in private bedrock wells in southeastern New Hampshire, 2012-2013

    Science.gov (United States)

    Flanagan, Sarah M.; Belaval, Marcel; Ayotte, Joseph D.

    2014-01-01

    Trace metals, such as arsenic, iron, lead, manganese, and uranium, in groundwater used for drinking have long been a concern because of the potential adverse effects on human health and the aesthetic or nuisance problems that some present. Moderate to high concentrations of the trace metal arsenic have been identified in drinking water from groundwater sources in southeastern New Hampshire, a rapidly growing region of the State (Montgomery and others, 2003). During the past decade (2000–10), southeastern New Hampshire, which is composed of Hillsborough, Rockingham, and Strafford Counties, has grown in population by nearly 48,700 (or 6.4 percent) to 819,100. These three counties contain 62 percent of the State’s population but encompass only about 22 percent of the land area (New Hampshire Office of Energy and Planning, 2011). According to a 2005 water-use study (Hayes and Horn, 2009), about 39 percent of the population in these three counties in southeastern New Hampshire uses private wells as sources of drinking water, and these wells are not required by the State to be routinely tested for trace metals or other contaminants. Some trace metals have associated human-health benchmarks or nonhealth guidelines that have been established by the U.S. Environmental Protection Agency (EPA) to regulate public water supplies. The EPA has established a maximum contaminant level (MCL) of 10 micrograms per liter (μg/L) for arsenic (As) and a MCL of 30 μg/L for uranium (U) because of associated health risks (U.S. Environmental Protection Agency, 2012). Iron (Fe) and manganese (Mn) are essential for human health, but Mn at high doses may have adverse cognitive effects in children (Bouchard and others, 2011; Agency for Toxic Substances and Disease Registry, 2012); therefore, the EPA has issued a lifetime health advisory (LHA) of 300 μg/L for Mn. Recommended secondary maximum contaminant levels (SMCLs) for Fe (300 μg/L) and Mn (50 μg/L) were established primarily as

  14. Histopathology of liver and kidneys of wild living Mallards Anas platyrhynchos and Coots Fulica atra with considerable concentrations of lead and cadmium.

    Science.gov (United States)

    Binkowski, Łukasz J; Sawicka-Kapusta, Katarzyna; Szarek, Józef; Strzyżewska, Emilia; Felsmann, Mariusz

    2013-04-15

    Concentrations of cadmium and lead were measured in liver and kidneys of Mallard (n=60) and Coot (n=50). Free living birds were collected by hunters in years 2006-2008 in the area of fishponds near Zator in southern Poland. Age group was determined according to the appearance of the plumage (Mallards) and iris color (Coot). Concentrations of metals were measured with ET-AA spectrometer. Among all birds specimens with negligible (n=5) and high concentrations (Mallards n=18 and Coots n=17) of cadmium and lead were chosen for further analysis. Histopathological alterations were observed, ranging from circulatory disturbances, retrogressive changes, inflammations to leukocytic infiltration in liver and kidney. They dominated among birds with the highest concentrations of metals. The control group of birds was characterized by a very small number of mentioned lesions. Probably the higher cadmium and lead concentrations in tissues are co-factors in the development of lesions.

  15. Determination of lead in water resources by flame atomic absorption spectrometry after pre-concentration with ammonium pyrrolidinedithiocarbamate immobilized on surfactant-coated alumina

    Directory of Open Access Journals (Sweden)

    SAYED MORTEZA TALEBI

    2007-06-01

    Full Text Available Arapid, simple, and sensitive procedure based on modified solid phase extraction was developed for the pre-concentration and determination of trace amount of lead in water resources. Lead was reacted with ammonium pyrrolidinedithiocarbamate (APDC to make a complex. The complex was then collected in a column packed with surfactant-coated alumina. The parameters affecting the collection efficiency and desorption rate of the lead complexes from the column were investigated and optimized. The collection efficiency of the lead complex on the adsorbent was excellent under the optimized conditions. The results obtained from the recovery test showed the capability and reliability of the method for the analysis of trace amounts of lead. The proposed pre-concentration procedure made it possible to apply conventional flame atomic absorption spectrometry (FAAS for the sensitive determination of trace amounts of lead in water resources.

  16. Exposure of human cartilage tissue to low concentrations of blood for a short period of time leads to prolonged cartilage damage: An in vitro study

    NARCIS (Netherlands)

    Jansen, N.W.D.; Roosendaal, G.; Bijlsma, J.W.J.; Groot, J. de; Lafeber, F.P.J.G.

    2007-01-01

    Objective. Joint bleeding, or hemarthrosis, leads in time to severe joint damage. This study was carried out to test the in vitro thresholds of exposure time and concentration that lead to irreversible joint damage, to add to the discussion on the usefulness of aspiration of the joint after a hemorr

  17. A Western Diet Pattern Is Associated with Higher Concentrations of Blood and Bone Lead among Middle-Aged and Elderly Men.

    Science.gov (United States)

    Wang, Xin; Ding, Ning; Tucker, Katherine L; Weisskopf, Marc G; Sparrow, David; Hu, Howard; Park, Sung Kyun

    2017-07-01

    Background: Little is known about the effects of overall dietary pattern on lead concentration.Objective: We examined the association of overall dietary patterns, derived from a semiquantitative food frequency questionnaire, with bone and blood lead concentrations.Methods: These longitudinal analyses included mostly non-Hispanic white, middle-aged-to-elderly men from the Veterans Affairs Normative Aging Study. Long-term lead exposures were measured as tibia and patella lead concentrations by using K-shell-X-ray fluorescence. Short-term lead exposures were measured as blood lead concentrations by using graphite furnace atomic absorption spectroscopy. Dietary pattern scores were derived by using factor analysis. Linear mixed-effects models were utilized to predict blood lead concentrations among 983 men, aged 44-92 y at baseline, with a total of 3273 observations (during 1987-2008). We constructed linear regression models to determine the relations between dietary patterns and bone lead concentrations among 649 participants with an age range of 49-93 y.Results: Two major dietary patterns were identified: a prudent dietary pattern, characterized by high intakes of fruit, legumes, vegetables, whole grains, poultry, and seafood; and a Western dietary pattern, characterized by high intakes of processed meat, red meat, refined grains, high-fat dairy products, French fries, butter, and eggs. After adjusting for age, smoking status, body mass index, total energy intake, education, occupation, neighborhood-based education and income level, men in the highest tertile of the Western pattern score (compared with the lowest) had 0.91 μg/dL (95% CI: 0.41, 1.42 μg/dL) higher blood lead, 5.96 μg/g (95% CI: 1.76, 10.16 μg/g) higher patella lead, and 3.83 μg/g (95% CI: 0.97, 6.70 μg/g) higher tibia lead. No significant association was detected with the prudent dietary pattern in the adjusted model.Conclusions: These findings suggest that the Western diet is associated with a

  18. Effects of pollution on lead and cadmium concentration and correlation with biochemical parameters in blood of human population nearby Kosovo thermo power plants

    Directory of Open Access Journals (Sweden)

    L. Zeneli

    2008-01-01

    Full Text Available This study describes an investigation of lead and cadmium pollution of Kosovo environment as a result of outflow from the coal processing industry. In a comparative study of lead and cadmium concentration in blood of human population of two different environments in Kosovo, one nearby Kosovo Thermo Power Plants, (Obiliq a highly polluted environment and the other that is considered as relatively clean rural environment (Dragash. Analysis has shown that emission of particulate in fly ash from Thermo Power Plants during 2005 has exceeded EU standards by 400-500% and that lead concentration was 18mg kg-1 and cadmium concentration was -1 of ash. A series of determinations of lead and cadmium concentrations in blood of population that lives in this environment, have shown direct effects in biochemical parameters CRE (Creatinin, DB (Direct Bilirubine, TB (Total Bilirubine, AST (Aspartat Aminotransferaza, CK (Creatin Kinaza and CHE (Cholenisteraza in human organism. The results that were achieved in this study showed a significant difference in average lead and cadmium concentration in the blood of the investigated group of peoples that lives in the area near by the Power Plants, from a control group that lives in a rural unpolluted environment. Lead and cadmium has been analyzed in 50 samples taken from persons from industrial zone and 25 samples in controlled group. The level of lead concentration was 23.0-112.1 µg L-1in geometric average 46.05 µg L-1, cadmium concentration was 0.44-6.02 µg L-1 in geometric average of 1.56µg L-1. Controlled group from the rural relatively clean environment showed lead concentration of 6.7-33.8 µg L-1 in geometric avarage 17.76 µg L-1 and cadmium concentration of 0.21-1.8 µg L-1 or in geometric average of 0.73 µg L-1. In conclusion in exposed subjects, pollution from coal burning in Power Plant is very important factor for level of lead and cadmium concentration in blood of tested population.

  19. [Interannual variation patterns of heavy metals concentrations in tree rings of Larix gmelinii near Xilin Lead-zinc Mine, Yichun of Northeast China].

    Science.gov (United States)

    Hu, Shen; Wang, Xiao-Chun; Yang, Jin-Yan

    2013-06-01

    By using dendro-environmental methods, this paper measured and analyzed the variations of five heavy metals (Pb, Cd, Zn, Cu, and Mn) concentrations in the tree rings of Larix gmelinii near Xilin Lead-zinc Mine, Yichun of Northeast China. Among the test heavy metals, the Mn concentration in the tree rings was the highest, while the Cd concentration was the lowest. The Cd, Zn, and Cu concentrations in the tree rings near the ground (0.3 m high from the ground, D0.3) were significantly higher than those at breast height (1.3 m high from the ground, D1.3), while the Pb and Mn concentrations at the two heights had less difference. In 1987-2010, the Pb concentration in the tree rings had a slight increase, but the Cd, Zn, Cu, and Mn concentrations presented a decreasing trend. The Cd concentration decreased most obviously, while the Zn, Cu, and Mn concentrations decreased after an initial increase. With the increase of tree ring width, the Pb concentration decreased, while the Cd, Zn, Cu, and Mn concentrations were in adverse. The relationships between the Pb and other four heavy metals concentrations in the tree rings near the ground and at breast height had definite differences. Near the ground, the Pb concentration showed a significant positive correlation with the other four heavy metals concentrations, but at breast height, less correlation was observed, and even, the Cd concentration decreased significantly with increasing Pb concentration. The variations of the heavy metals concentrations in the L. gmelinii tree rings could be affected by the production and mining activities of Xilin Lead-zinc Mine, an thus, it would be possible to use the Pb concentration in the tree rings to reconstruct the mining his tory of the study area. At present, the Pb concentration in the tailing wastes has polluted the surrounding environments near Xilin Lead-zinc Mine. Therefore, countermeasures should be adopted to manage the heavy metals in tailing wastes if the Mine would be

  20. Persistence of high lead concentrations and associated effects in Tundra Swans captured near a mining and smelting complex in northern Idaho

    Science.gov (United States)

    Blus, L.J.; Henny, C.J.; Hoffman, D.J.; Sileo, L.; Audet, D.J.

    1999-01-01

    Lead poisoning of waterfowl, particularly tundra swans (Cygnus columbianus), has been documented in the Coeur d'Alene River Basin in northern Idaho for nearly a century. Over 90% of the lead-poisoned tundra swans in this area that were necropsied have no ingested lead shot. Spent lead shot from hunting activities over the years is therefore a minor source of lead in these swans. The migrating swans accumulated lethal burdens of lead from ingestion of sediments and aquatic vegetation during a short stopover in the spring. The lead originated from mining and smelting activities. Lead concentrations and physiological characteristics of blood were compared in swans captured in swim-in traps, with moribund swans caught by hand in the lead-contaminated area in 1987 and 1994-1995 and with birds captured by night-lighting in reference areas in 1994-1995. Blood lead concentrations in swans were highest in moribund birds (3.3 ?g g-1 in 1987 and 1995), intermediate in those trapped in the contaminated area (0.82 ?g g-1 in 1987 and 1.8 ?g g-1 in 1995), and lowest (0.11 ?g g-1) in those trapped in the reference areas. daminolevulinic acid dehydratase (ALAD) was significantly inhibited in swans from the contaminated area. Hematocrit and hemoglobin were significantly depressed only in moribund swans. Of the 19 swans found moribund and euthanized, 18 were classified as having lead toxicosis on the basis of lead levels in blood (1.3 to 9.6 ?g g-1) and livers (6 to 40 ?g g-1) and necropsy findings. The 19th swan had aspergillosis. There was no evidence that effects of lead on tundra swans had diminished from 1987 to 1995.

  1. Automatic on-line pre-concentration system using a knotted reactor for the FAAS determination of lead in drinking water

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Anderson S. [Universidade Federal da Bahia, Instituto de Quimica, Nucleo de Excelencia em Quimica Analitica da Bahia, Campus Universitario de Ondina, Salvador, Bahia 40170-290 (Brazil); Universidade Estadual de Santa Cruz, Ilheus, Bahia (Brazil); Brandao, Geovani C. [Universidade Federal da Bahia, Instituto de Quimica, Nucleo de Excelencia em Quimica Analitica da Bahia, Campus Universitario de Ondina, Salvador, Bahia 40170-290 (Brazil); Santos, Walter N.L. dos [Universidade Estadual de Santa Cruz, Ilheus, Bahia (Brazil); Lemos, Valfredo A. [Universidade Estadual do Sudoeste da Bahia, Campus de Jequie, Jequie, Bahia 45206-190 (Brazil); Ganzarolli, Edgard M. [Universidade Estadual do Centro-Oeste, Departamento de Quimica, Rua Presidente Zacarias, 875, CP 33010, 85010-990 Guarapuava, PR (Brazil); Bruns, Roy E. [Universidade Estadual de Campinas, Instituto de Quimica, CP 6154, 13083-970 Campinas, SP (Brazil); Ferreira, Sergio L.C. [Universidade Federal da Bahia, Instituto de Quimica, Nucleo de Excelencia em Quimica Analitica da Bahia, Campus Universitario de Ondina, Salvador, Bahia 40170-290 (Brazil)]. E-mail: slcf@ufba.br

    2007-03-22

    An automatic on-line pre-concentration system is proposed for lead determination in drinking water using flame atomic absorption spectrometry (FAAS). Lead(II) ions are retained as the 1-(2-pyridylazo)-2-naphthol (PAN) complex in the walls of a knotted reactor, followed by an elution step using 0.50 mol L{sup -1} hydrochloric acid solution. Optimisation involving the sampling flow rate, pH and buffer concentration factors was performed using a Box-Behnken design. Other factors were established considering results of previous experiments. The procedure allows the determination of lead with a 0.43 {mu}g L{sup -1} detection limit (3{sigma}/S) and precisions (expressed as relative standard deviation) of 4.84% (N = 7) and 2.9% (N = 7) for lead concentrations of 5 and 25 {mu}g L{sup -1}, respectively. The accuracy was confirmed by the determination of lead in the NIST SRM 1643d trace elements in natural water standard reference material. The pre-concentration factor obtained is 26.5 and the sampling frequency is 48 h{sup -1}. The recovery achieved for lead determination in the presence of several ions demonstrated that this procedure could be applied to the analysis of drinking water samples. The method was applied for lead determination in drinking water samples collected in Jequie City, Brazil. The lead concentration found in 25 samples were always lower than the permissible maximum levels stipulated by World Health Organization.

  2. Association of anemia, child and family characteristics with elevated blood lead concentrations in preschool children from Montevideo, Uruguay.

    Science.gov (United States)

    Queirolo, Elena I; Ettinger, Adrienne S; Stoltzfus, Rebecca J; Kordas, Katarzyna

    2010-01-01

    Elevated blood lead levels (BPbs) have been identified in Uruguayan children in the La Teja neighborhood of Montevideo, but the extent of lead exposure in other city areas is unknown. Sources and predictors of exposure also remain understudied in this population. In 2007, the authors screened lead and hemoglobin levels in capillary blood of 222 preschool children from several areas of Montevideo, Uruguay, and identified predictors of elevated BPbs. Mean BPb was 9.0 +/- 6.0 microg/dL and 32.9% of children had levels >or= 10microg/dL. Mean hemoglobin level was 10.5 +/- 1.5 g/dL, with 44.1% having levels lead exposure, and fewer family possessions were also associated with higher BPbs. Pediatric lead exposure is a public health problem in Uruguay, with children experiencing elevated BPbs at a young age.

  3. Lead concentration in blood of school children from copper mining area and the level of somatic development at birth

    Directory of Open Access Journals (Sweden)

    Teresa Sławińska-Ochla

    2011-12-01

    Full Text Available Background. The aim of the study was to assess the relations between lead intoxication in children at younger school age and the level of somatic development at birth. Materials and Methods. The research includes 717 children and adolescents 7–15 years old from LegnickoGłogowski copper mining region, which live in the vincity of „Głogów”, „Legnica” copper industrial plants and flotation tank reservoir „Żelazny most”. The analysis contained measures such as birth height, birth weight, Apgar score points, and blood lead level in 2007 and 2008. The whole blood lead level (Pb-B was indicated using atomic absorption spectrometry (AAS with electrothermic atomization by certified The Foundation for Children From The Copper Basin laboratory. Results.Rural childrenwere noted forsignificantly higher blood lead levelsthan urban peers. Also boysin comparison to girls had higher blood lead levels. Regardless of gender and place of residence there were no significant correlation between blood lead level and body mass at birth. Conclusion. The biological state of the organism at the moment of birth has no connection with the susceptibility to absorption of lead in the later phases of ontogenesis: the earlier school age and adlescence.

  4. Association of lead concentration in colostrum, maternal and cord blood with newborn weight in polluted vs. non-polluted areas of Iran

    Directory of Open Access Journals (Sweden)

    Golmohammadi T.

    2007-10-01

    Full Text Available Background: Lead poisoning has proven to be one of the most important environmental health problems among developing countries with both direct and indirect effects on human life. Lead is known to cross the blood-brain barrier and placenta, and accumulates in soft and hard tissues. Lead can be excreted in urine, stool, milk, sweat, nails and saliva. During pregnancy and lactation, lead is released from bones into the blood along with Ca2+. The toxic effects of lead on various human tissues have been studied extensively, but few studies have addressed its impact on fetal development during pregnancy. Blood levels of lead are higher in people living in lead-polluted regions. It has been reported that Tehran (central and southern parts is the most problematic city in terms of lead poisoning.Methods: From 86 sets of mothers and newborns in a non-polluted area of rural Rasht, Iran, we examined specimens of maternal blood, cord blood and colostrum (86×3=258 and specimens from 85 sets of mothers and newborns in a polluted area of Tehran, Iran (85×3=255 for lead levels using atomic absorption spectrophotometry (AAS and analyzed the results by t-test, SPSS, and linear regression.Results: The mean blood lead concentrations of mothers, cord blood of newborns and colostrum were 7.6±4.1, 5.9±3 and 4.2±2.5 μg/dl, respectively, in the non-polluted area and 9.1±8.4, 6.5±5.2 and 5.8±5.5 μg/dl, respectively, in the polluted area. The mean weights of the newborns in non-polluted and polluted areas were 3.2±0.5 kg and 3.2±4.5 kg, respectively.Conclusions: Our data revealed an association between mean concentrations in blood lead of mothers and newborns and between mean concentrations of colostrum lead and newborn blood lead in both areas (p=0.01. There was no association between mean blood lead concentration of mothers with the weight of their newborns (p=0.89.

  5. Histopathology of liver and kidneys of wild living Mallards Anas platyrhynchos and Coots Fulica atra with considerable concentrations of lead and cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Binkowski, Łukasz J., E-mail: ljbinkowski@gmail.com [Institute of Biology, Pedagogical University of Cracow, Podbrzezie 3, 31-054 Cracow (Poland); Sawicka-Kapusta, Katarzyna, E-mail: katarzyna.sawicka-kapusta@uj.edu.pl [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Cracow (Poland); Szarek, Józef, E-mail: szarek@uwm.edu.pl [Department of Pathophysiology, Forensic Veterinary Medicine and Administration, University of Warmia and Mazury, Oczapowskiego 13, 10-719 Olsztyn (Poland); Strzyżewska, Emilia, E-mail: emijel@wp.pl [Department of Pathophysiology, Forensic Veterinary Medicine and Administration, University of Warmia and Mazury, Oczapowskiego 13, 10-719 Olsztyn (Poland); Felsmann, Mariusz, E-mail: felsmann.mariusz@wp.pl [Department of Pathophysiology, Forensic Veterinary Medicine and Administration, University of Warmia and Mazury, Oczapowskiego 13, 10-719 Olsztyn (Poland)

    2013-04-15

    Concentrations of cadmium and lead were measured in liver and kidneys of Mallard (n = 60) and Coot (n = 50). Free living birds were collected by hunters in years 2006–2008 in the area of fishponds near Zator in southern Poland. Age group was determined according to the appearance of the plumage (Mallards) and iris color (Coot). Concentrations of metals were measured with ET-AA spectrometer. Among all birds specimens with negligible (n = 5) and high concentrations (Mallards n = 18 and Coots n = 17) of cadmium and lead were chosen for further analysis. Histopathological alterations were observed, ranging from circulatory disturbances, retrogressive changes, inflammations to leukocytic infiltration in liver and kidney. They dominated among birds with the highest concentrations of metals. The control group of birds was characterized by a very small number of mentioned lesions. Probably the higher cadmium and lead concentrations in tissues are co-factors in the development of lesions. - Highlights: ► High levels of Cd and Pb were found in liver and kidneys of Mallard and Coot. ► Lower concentrations were found in young birds. ► Amount of metals exceeded the safety threshold established for edible poultry. ► Histopathological alterations were found in studied tissues. ► Lesions in birds with the highest concentrations of metals were numerous.

  6. Analyzing lead concentration in the sycamore tree species in high- and low-traffic areas of Rasht, Iran.

    Science.gov (United States)

    Hashemi, Seyed Armin; Alinejad, Farzaneh; FallahChay, Mozaffar

    2015-06-01

    Important heavy metals such as lead and cadmium are part of the pollutants produced by cars and are spread in the urban environment by traffic flow. In order to study the amount of contamination in the trees along the streets and to determine the traffic parameters that affect the lead content in sycamore leaves in Rasht, four stations on the margins of the city streets were selected for this case study in terms of traffic volume (low or high). Traffic parameters including three high-traffic stations considering daily and monthly traffic volumes and one low-traffic station were selected. First, 32 sycamore bases were randomly chosen at the intervals of 10-15 m from the whole range of tree canopy in order to determine the absorption of lead; and then, 20 g of each sample were tested to determine the amount of lead absorption. The results of this study, on the amount of lead absorption by the sycamore tree species at three high-traffic and one control station, showed that Takhti station had the highest amount of lead absorption (37.19 ppm) compared with other three stations. Therefore, the sycamore tree species can be an appropriate one for the margins of urban streets.

  7. A pre-concentration procedure using coprecipitation for determination of lead and iron in several samples using flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Saracoglu, S. [Erciyes University, Faculty of Education, 38039 Kayseri (Turkey); Soylak, M. [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)]. E-mail: soylak@erciyes.edu.tr; Peker, D.S. Kacar [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey); Elci, L. [Pamukkale University, Faculty of Science and Arts, Chemistry Department, 20020 Denizli (Turkey); Santos, W.N.L. dos [Universidade Estadual de Santa Cruz lheus, Bahia (Brazil); Lemos, V.A. [Universidade Estadual do Sudoeste da Bahia, Nucleo de Quimica Analitica da Bahia (NQA), Laboratorio de Quimica Analitica (LQA), Campus de Jequie, 45200-000 Jequie, BA (Brazil); Ferreira, S.L.C. [Instituto de Quimica, Universidade Federal da Bahia, Campus Universitario de Ondina, 40.170-280 Salvador, BA (Brazil)

    2006-08-04

    The present paper proposes a pre-concentration procedure for determination of lead and iron in several samples by flame atomic absorption spectrometry. In it, lead(II) and iron(III) ions are coprecipitated using the violuric acid-copper(II) system as collector. Afterwards, the precipitate is dissolved with 1 M HNO{sub 3} solution and the metal ions are determined. The optimization step was performed using factorial design involving the variables: pH, violuric acid mass (VA) and copper concentration (Cu). Using the optimized experimental conditions, the proposed procedure allows the determination these metals with detection limits of 0.18 {mu}g L{sup -1} for iron and 0.16 {mu}g L{sup -1} for lead. The effects of foreign ions on the pre-concentration procedure were also evaluated and the results demonstrated that this method could be applied for determination of iron and lead in several real samples. The proposed method was successfully applied to the analysis of seawater, urine, mineral water, soil and physiological solution samples. The concentrations of lead and iron achieved in these samples agree well with others data reported in the literature.

  8. Physical Activity and Blood Lead Concentration in Korea: Study Using the Korea National Health and Nutrition Examination Survey (2008-2013).

    Science.gov (United States)

    Rhie, Jeongbae; Lee, Hye-Eun

    2016-06-01

    Physical activity normally has a positive influence on health, however it can be detrimental in the presence of air pollution. Lead, a heavy metal with established adverse health effects, is a major air pollutant. We evaluated the correlation between blood lead concentration and physical activity using data collected from the Korea National Health and Nutrition Examination Survey. Multivariate logistic regression analysis was performed after dividing participants according to whether they were in the top 25% in the distribution of blood lead concentration (i.e., ≥ 2.76 µg/dL), with physical activity level as an independent variable and adjusting for factors such as age, sex, drinking, smoking, body mass index, region, and occupation. The high physical activity group had greater odds of having a blood lead concentration higher than 2.76 µg/dL (odds ratio 1.29, 95% CI 1.11-1.51) compared to the low physical activity group. Furthermore, blood lead concentration is correlated with increasing physical activity.

  9. Ketamine coadministration attenuates morphine tolerance and leads to increased brain concentrations of both drugs in the rat

    Science.gov (United States)

    Lilius, T O; Jokinen, V; Neuvonen, M S; Niemi, M; Kalso, E A; Rauhala, P V

    2015-01-01

    Background and Purpose The effects of ketamine in attenuating morphine tolerance have been suggested to result from a pharmacodynamic interaction. We studied whether ketamine might increase brain morphine concentrations in acute coadministration, in morphine tolerance and morphine withdrawal. Experimental Approach Morphine minipumps (6 mg·day–1) induced tolerance during 5 days in Sprague–Dawley rats, after which s.c. ketamine (10 mg·kg–1) was administered. Tail flick, hot plate and rotarod tests were used for behavioural testing. Serum levels and whole tissue brain and liver concentrations of morphine, morphine-3-glucuronide, ketamine and norketamine were measured using HPLC-tandem mass spectrometry. Key Results In morphine-naïve rats, ketamine caused no antinociception whereas in morphine-tolerant rats there was significant antinociception (57% maximum possible effect in the tail flick test 90 min after administration) lasting up to 150 min. In the brain of morphine-tolerant ketamine-treated rats, the morphine, ketamine and norketamine concentrations were 2.1-, 1.4- and 3.4-fold, respectively, compared with the rats treated with morphine or ketamine only. In the liver of morphine-tolerant ketamine-treated rats, ketamine concentration was sixfold compared with morphine-naïve rats. After a 2 day morphine withdrawal period, smaller but parallel concentration changes were observed. In acute coadministration, ketamine increased the brain morphine concentration by 20%, but no increase in ketamine concentrations or increased antinociception was observed. Conclusions and Implications The ability of ketamine to induce antinociception in rats made tolerant to morphine may also be due to increased brain concentrations of morphine, ketamine and norketamine. The relevance of these findings needs to be assessed in humans. PMID:25297798

  10. Validation of Bayesian kriging of arsenic, chromium, lead, and mercury surface soil concentrations based on internode sampling.

    Science.gov (United States)

    Aelion, C M; Davis, H T; Liu, Y; Lawson, A B; McDermott, S

    2009-06-15

    Bayesian kriging is a useful tool for estimating spatial distributions of metals; however, estimates are generally only verified statistically. In this study surface soil samples were collected on a uniform grid and analyzed for As, Cr, Pb, and Hg. The data were interpolated at individual locations by Bayesian kriging. Estimates were validated using a leave-one-out cross validation (LOOCV) statistical method which compared the measured and LOOCV predicted values. Validation also was carried out using additional field sampling of soil metal concentrations at points between original sampling locations, which were compared to kriging prediction distributions. LOOCV results suggest that Bayesian kriging was a good predictor of metal concentrations. When measured internode metal concentrations and estimated kriged values were compared, the measured values were located within the 5th-95th percentile prediction distributions in over half of the internode locations. Estimated and measured internode concentrations were most similar for As and Pb. Kriged estimates did not compare as well to measured values for concentrations below the analytical minimum detection limit, or for internode samples that were very close to the original sampling node. Despite inherent variability in, metal concentrations in soils, the kriged estimates were validated statistically and by in situ measurement.

  11. Blood Lead Concentrations of Children in the United States: A Comparison of States Using Two Very Large Databases.

    Science.gov (United States)

    Shah, Keneil K; Oleske, James M; Gomez, Hernan F; Davidow, Amy L; Bogden, John D

    2017-06-01

    To determine whether there are substantial differences by state between 2 large datasets in the proportion of children with elevated blood lead levels (BLLs); to identify states in which the percentage of elevated BLLs is high in either or both datasets; and to compare the percentage of elevated BLLs in individual states with those of children living in Flint, Michigan, during the months when these children were exposed to lead-contaminated drinking water. Tables of BLLs for individual states from the Quest Diagnostics and the Centers for Disease Control and Prevention datasets for 2014-2015, containing more than 3 million BLLs of young children?lead exposure (primary prevention) and identify children with elevated BLLs (secondary prevention). Published by Elsevier Inc.

  12. Concentrations of Mercury, Lead, Chromium, Cadmium, Arsenic and Aluminum in Irrigation Water Wells and Wastewaters Used for Agriculture in Mashhad, Northeastern Iran

    Directory of Open Access Journals (Sweden)

    M Sadeghi

    2013-04-01

    Full Text Available Background: Contamination of water by toxic chemicals has become commonly recognized as an environmental concern. Based on our clinical observation in Mashhad, northeastern Iran, many people might be at risk of exposure to high concentrations of toxic heavy metals in water. Because wastewater effluents as well as water wells have been commonly used for irrigation over the past decades, there has been some concern on the toxic metal exposure of crops and vegetables irrigated with the contaminated water.Objective: To measure the concentrations of mercury, lead, chromium, cadmium, arsenic and aluminium in irrigation water wells and wastewaters used for agriculture in Mashhad, northeastern Iran.Methods: 36 samples were taken from irrigation water wells and a wastewater refinery in North of Mashhad at four times—May 2008, March 2009, and June and July 2010. Atomic absorption spectrometry was used to measure the concentration of toxic metals. Graphite furnace was used for the measurement of lead, chromium, cadmium and aluminum. Mercury and arsenic concentrations were measured by mercury/hydride system.Results: Chromium, cadmium, lead and arsenic concentrations in the samples were within the standard range. The mean±SD concentration of mercury in irrigation wells (1.02±0.40 μg/L exceeded the FAO maximum permissible levels. The aluminum concentration in irrigation water varied significantly from month to month (p=0.03. All wastewater samples contained high mercury concentrations (6.64±2.53 μg/L.Conclusion: For high mercury and aluminum concentrations, the water sources studied should not be used for agricultural use. Regular monitoring of the level of heavy metals in water and employing the necessary environmental interventions in this area are strongly recommended.

  13. Associations between land cover categories, soil concentrations of arsenic, lead and barium, and population race/ethnicity and socioeconomic status.

    Science.gov (United States)

    Davis, Harley T; Aelion, C Marjorie; Lawson, Andrew B; Cai, Bo; McDermott, Suzanne

    2014-08-15

    The potential of using land cover/use categories as a proxy for soil metal concentrations was examined by measuring associations between Anderson land cover category percentages and soil concentrations of As, Pb, and Ba in ten sampling areas. Land cover category and metal associations with ethnicity and socioeconomic status at the United States Census 2000 block and block group levels also were investigated. Arsenic and Pb were highest in urban locations; Ba was a function of geology. Consistent associations were observed between urban/built up land cover, and Pb and poverty. Land cover can be used as proxy for metal concentrations, although associations are metal-dependent. Copyright © 2014. Published by Elsevier B.V.

  14. Coupling lead isotopes and element concentrations in epiphytic lichens to track sources of air emissions in the Alberta Oil Sands Region

    Science.gov (United States)

    A study was conducted that coupled use of element concentrations and lead (Pb) isotope ratios in the lichen Hypogymnia physodes collected during 2002 and 2008, to assess the impacts of air emissions from the Alberta Oil Sands Region (AOSR, Canada) mining and processing operations...

  15. Coupling lead isotopes and element concentrations in epiphytic lichens to track sources of air emissions in the Alberta Oil Sands Region

    Science.gov (United States)

    A study was conducted that coupled use of element concentrations and lead (Pb) isotope ratios in the lichen Hypogymnia physodes collected during 2002 and 2008, to assess the impacts of air emissions from the Alberta Oil Sands Region (AOSR, Canada) mining and processing operations...

  16. Critical soil concentrations of cadmium, lead and mercury in view of health effects on humans and animals

    NARCIS (Netherlands)

    Vries, de W.; Romkens, P.F.A.M.; Schutze, G.

    2007-01-01

    To assess the impact of elevated concentrations of metals in terrestrial ecosystems, a major distinction should be made in risks/effects of heavy metals related to (i) the soil ecosystem (soil organisms/processes and plants) and (ii) human health or animal health resulting from bioaccumulation. The

  17. Purification and Concentration of PCR Products Leads to Increased Signal intensities with Fewer Allelic Drop-Outs and Artifacts

    DEFF Research Database (Denmark)

    Maria Irlund Pedersen, Line; Stangegaard, Michael; Mogensen, Helle Smidt;

    2011-01-01

    Capillary electrophoresis of amplified DNA isolated from trace evidence samples occasionally results in inadequate STR-profiles due to artifacts caused by e.g. primers and dNTPs. Removal of artifacts by purification and subsequent concentration of the PCR products may increase the sensitivity...

  18. Critical soil concentrations of cadmium, lead and mercury in view of health effects on humans and animals

    NARCIS (Netherlands)

    Vries, de W.; Romkens, P.F.A.M.; Schutze, G.

    2007-01-01

    To assess the impact of elevated concentrations of metals in terrestrial ecosystems, a major distinction should be made in risks/effects of heavy metals related to (i) the soil ecosystem (soil organisms/processes and plants) and (ii) human health or animal health resulting from bioaccumulation. The

  19. Fish Protein Concentrate Fortification Siam Patin on Amplang Snack Products and Mi Sago Instant Product as a Leading Regional Riau

    Directory of Open Access Journals (Sweden)

    Dewita Buchari

    2014-11-01

    Full Text Available To enhance fish consumption in the community especially children, fortification on processed fish product is conducted. The processed fish products are developed to fill the requirements as the fish based food products that own characterizations such as ready to eat, easy to carry, and less time to cook. Amplang snacks and instant sagoo noodles are defined as the products that fills the requirements. The research was aimed to process catfish into fish protein concentrate to become amplang snack and instant sagoo noodles. These products were designed as the effort to develop the local priority products in Riau by using diversification and fortification methods. Experimental method with fortification treatments on Fish Protein Concentrate (FPC extract from Catfish that generate products of amplang snacks and instant sagoo noodles and fish tofu were carried out. The fortified products were examined by organoleptics test that involved panelists. The results showed that the proximate analysis on fortified Catfish Protein Concentrate products were presented as following :1. water contents of 3,13 %, ash of 2,85 %, protein content of 16,13 % and fat content of 18, 66 % for ampang snacks; and 2. water contents of 11,77 %, ash of 1,30 %, protein content of 12,35 % and fat content of 1,86 % for instant sagoo nodles. All fortified FPC products filled the Indonesian Nasional Standard (SNI.Keywords: Fortification, Catfish, and Fish Protein Concentrate

  20. Analysis of anomalous high concentration of lead and selenium and their origin in the main minable coal seam in the Junger coalfield

    Energy Technology Data Exchange (ETDEWEB)

    Li Sheng-sheng; Ren De-yi [State Administration of Work Safety, Beijing (China)

    2006-07-01

    The concentration, occurrence, and geological origin of lead and selenium in the main minable coal seam from the Junger coalfield were studied using inductively coupled plasma mass spectrometry (CICP-MS), instrumental neutron activation analysis (CINAA), scanning electron microscope equipped with an energy-dispersive X-ray spectrometer (SEM-EDX), and optical microscope. The results show that the average concentrations of Pb and Se are as high as 35.7 {mu}g/g and 8.2 {mu}g/g, respectively, which are much higher than those of coals from North China, Guizhou, China, and USA. In addition, their enrichment factors are up to 2.4 and 68.1, respectively. Lead and selenium are significantly enriched in the seam. Lead and selenium mainly exist in galena, clausthalite, and selenio-galena which occur as cell-filling of coal-forming plants and are of chemical-sedimentary origin. 22 refs., 3 figs., 1 tab.

  1. DETERMINATION OF LEAD (Pb, IRON (Fe AND MANGANESE (Mn CONCENTRATION IN SEWAGE WATER AND VEGETABLE LEAF SAMPLES

    Directory of Open Access Journals (Sweden)

    Muhammad Umar Hayat

    2015-04-01

    Full Text Available Application of waste water for irrigation purposes has increased over the past years. This waste water contains high amounts of trace elements and heavy metals.Many of these are non-essential and toxic to plants, animals and human beings. The use of polluted water in the immediate surroundings of big cities in Pakistan is a common practice for growing of vegetables. When this water applied for long time in irrigation, these heavy metals may accumulate in soil and that may be toxic to plants and also cause deterioration of soil. The present study revealed that heavy metal content was above the toxicity level in leafy vegetables grown in the area of Lahore. This study showed that among the different tested plant species, the amount of heavy metals was more in leaves than fruits. Plants whose fruits grow below the soil showed higher concentration of heavy metals while other showed less concentration whose edible portion was above the ground level. Leafy vegetables (spinach, cabbage, coriander etc showed higher concentration in leaves than in fruits. The concentration of heavy metals in upper layer of soil (0 -15 cm is higher than the lower layer (15-30 cm. The reason behind is that the upper layer was receiving sewage water permanently while the penetration of sewage water below 15 cm was less. The increase in heavy metal accumulation in different plant species and their different parts is not constant and is not in proportion to the increase in heavy metal concentration in soil irrigated with sewage wastewater.

  2. Simple method of determination of copper, mercury and lead in potable water with preliminary pre-concentration by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Hołyńska, B.; Ostachowicz, B.; Wȩgrzynek, D.

    1996-06-01

    Total reflection X-ray fluorescence spectrometry and chemical pre-concentration procedures have been applied for the analysis of trace concentrations of copper, mercury, and lead in drinking water samples. A simple total reflection module has been used in X-ray measurements. The elements under investigation were pre-concentrated by complexation using a mixture of carbamates followed by solvent extraction with methyl isobutyl ketone. The preconcentration procedure was tested with the use of twice-distilled water samples and samples of mineral and tap water spiked with known additions of copper, mercury, and lead. The obtained recovery and precision values are presented. The minimum detection limits for the determination of these elements in mineral and tap water samples were found to be 40 ng l -1, 60 ng l -1, and 60 ng l -1, respectively.

  3. Determination of the geographic origin of rice by chemometrics with strontium and lead isotope ratios and multielement concentrations.

    Science.gov (United States)

    Ariyama, Kaoru; Shinozaki, Miyuki; Kawasaki, Akira

    2012-02-22

    The objective of this study was to develop a technique for determining the country of origin of rice in the Japanese market. The rice samples included a total of 350 products grown in Japan (n = 200), the United States (n = 50), China (n = 50), and Thailand (n = 50). In this study, (87)Sr/(86)Sr and Pb isotope ((204)Pb, (206)Pb, (207)Pb, and (208)Pb) ratios and multielement concentrations (Al, Fe, Co, Ni, Cu, Rb, Sr, and Ba) were determined by high-resolution inductively coupled plasma mass spectrometry. By combining three chemometric techniques based on different principles and determination criteria, the countries of origin of rice were determined. The predictions made by 10-fold cross-validation were around 97% accurate. The presented method demonstrated the effectiveness of determining the geographic origin of an agricultural product by combining several chemometric techniques using heavy element isotope ratios and multielement concentrations.

  4. Purification and Concentration of PCR Products Leads to Increased Signal intensities with Fewer Allelic Drop-Outs and Artifacts

    DEFF Research Database (Denmark)

    Maria Irlund Pedersen, Line; Stangegaard, Michael; Mogensen, Helle Smidt

    2011-01-01

    Capillary electrophoresis of amplified DNA isolated from trace evidence samples occasionally results in inadequate STR-profiles due to artifacts caused by e.g. primers and dNTPs. Removal of artifacts by purification and subsequent concentration of the PCR products may increase the sensitivity...... and the quality of the DNA profiles without re-amplification of the sample. We have validated and implemented an automated method to purify and 2-fold concentrate PCR products resulting in allelic peaks with higher intensity (a median height across all loci from 130 to 404 RFU), fewer allelic dropouts...... and a reduced number of artifacts compared to both an increase in injection time and increase in the number of amplification cycles....

  5. Nonideal diffusion effects and short-range ordering lead to higher aggregation rates in concentrated hard-sphere dispersions.

    Science.gov (United States)

    Kelkar, Aniruddha V; Franses, Elias I; Corti, David S

    2014-04-08

    Brownian aggregation in concentrated hard-sphere dispersions is studied using models and Brownian dynamics (BD) simulations. Two new theoretical models are presented and compared to several existing approaches and BD simulation results, which serve as benchmarks. The first new model is an improvement over an existing local density approximation (LDA)-based model. The other is based on the more rigorous Fundamental measure theory (FMT) applied to the "liquid-state" dynamic density-functional theory (DDFT). Both models provide significant improvements over the classical Smoluchowski model. The predictions of the new FM-DDFT-based model for aggregation kinetics are in excellent agreement with BD simulation results for dispersions with initial particle volume fractions, ϕ, up to 0.35 (close to the hard-sphere freezing transition at ϕ = 0.494). In contrast to previous approaches, the nonideal particle diffusion effects and the initial and time-dependent short-range ordering in concentrated dispersions due to entropic packing effects are explicitly considered here, in addition to the unsteady-state effects. The greater accuracy of the FM-DDFT-based model compared to that of the LDA-based models indicates that nonlocal contributions to particle diffusion (only accounted for in the former) play important roles in aggregation. At high concentrations, the FM-DDFT-based model predicts aggregation half-times and gelation times that are up to 2 orders of magnitude shorter than those of the Smoluchowski model. Moreover, the FM-DDFT-based model predicts asymmetric cluster-cluster aggregation rate constants, at least for short times. Overall, a rigorous mechanistic understanding of the enhancement of aggregation kinetics in concentrated dispersions is provided.

  6. CADMIUM, COPPER, LEAD AND ZINC CONCENTRATIONS IN LOW QUALITY WINES AND ALCOHOL CONTAINING DRINKS FROM ITALY, BULGARIA AND POLAND

    Directory of Open Access Journals (Sweden)

    Renata Muchacka

    2012-02-01

    Full Text Available We studied Cu, Cd, Pb and Zn concentrations in low quality wines produced in Bulgaria and Italy and in alcohol containing multi-fruit drinks produced in Poland. All the metals were present in tested products. Cadmium was not detected in Italian and Polish products. In one of the Bulgarian wines cadmium was detected in concentration of 0.004 mg•l-1. Italian wines were not contaminated with Pb. Its concentration was the highest in Polish drinks (0.88±0.52 mg•l-1. The largest and statistically significant differences occurred between Cu and Zn contents. Both metals had the highest concetrations in Italian wines (Cu - 0.13±0.05 mg•l-1; Zn - 0.83±0.56 mg•l-1, and the lowest in Polish products (Cu - 0.04±0.001 mg•l-1; Zn -0.18±0.16 mg•l-1.

  7. Concentration of lead, cadmium, and iron in sediment dust and total suspended particles before and after initialisation of integral production in iron and steel work plant Zenica.

    Science.gov (United States)

    Prcanović, Halim; Duraković, Mirnes; Beganović, Sanela

    2012-06-01

    Poor air quality is a common fact for all areas with base industry. The city of Zenica was once the metallurgical centre of Ex-Yugoslavia and is therefore highly polluted at present. Air pollution peaked in 1987 when average concentration of pollutants was extremely high (daily average concentration of SO(2) was 1800 μg m(-3)). With the beginning of the war in 1992, integral production in the steel work plant was shut down, to be re-launched in 2008. Limit values for iron do not exist, but iron has been monitored in Zenica for the past 28 years because of the presence of steel works. Concentrations of cadmium and lead have also been measured because they are very much present in polluted areas with steel works. The concentration of mentioned elements in air deposit and total suspended particles before and after integral production in the steel work plant was re-launched is the subject of this paper. Total suspended particles were measured in two locations using German standard VDI 2463 Blatt 4. Sediment dust was measured in nine locations using Bergerhoff method. The concentration of iron, lead, and cadmium was performed in the chemical laboratory of the Metallurgical Institute "Kemal Kapetanović" Zenica using standard methods. Higher concentrations of these parameters during the period of integral production clearly point to the impact of steel works on Zenica valley.

  8. Microalbuminuria en ratas tratadas con plomo en bajas concentraciones Microalbuminuria In Rats With Low Lead Concentrations Treatment

    Directory of Open Access Journals (Sweden)

    Nora Martínez Riera

    2008-07-01

    Full Text Available La función endotelial puede ser modificada por tóxicos ambientales como el plomo; la microalbuminuria es un marcador de disfunción endotelial y refleja alteración temprana y generalizada de la misma. La microalbuminuria, es un marcador de riesgo renal y un potente indicador de riesgo de morbi - mortalidad cardiovascular. Objetivo: Evaluar si el tratamiento con bajas concentraciones de plomo (0,5 ppm produce microalbuminuria y si ésta sufre modificaciones con el tiempo de exposición al metal. Se trabajó con ratas blancas de la cepa Wistar, tratadas con 0,5 ppm de acetato de plomo en el agua de bebida. Los animales se separaron en tres grupos según el tiempo de tratamiento con el tóxico: 6, 9 y 12 meses; el cuarto grupo constituyó el control no tratado, con agua ad libitum. Laboratorio: Plombemia por absorción atómica, determinación de microalbuminuria por el método turbidimétrico (látex de Biosystems. Resultados: ratas controles promedio de microalbuminuria: 2,41± 0,79 mg/dl. Ratas tratadas durante 6 meses, 9 meses y 12 meses fue de 3,25 ± 1,05 mg/dl, 6,17 ± 1,24 mg/dl y 27,4 ± 15,78 mg/dl, respectivamente. Al comparar el grupo control con cada uno de los grupos tratados se observaron en todos los casos diferencias significativas, pThe endothelial function can be modified by environmental toxics as lead; microalbuminuria is a marker of endotelial disfunción and reflects early and generalized alteration of it. Microalbuminuria, is a marker of renal risk, and a powerful indicator of cardiovascular risk mortality. Objective: evaluate if low level lead treatment (0.5 ppm produces microalbuminuria and if it undergoes modifications with time of exposition. Wistar rats, with 0.5 ppm lead acetate in the drink water were included. The animals were separated in three groups according to the time of treatment in: 6, 9 and 12 months; the fourth group constituted of control with water ad libitum. Laboratory: Plombemia by atomic absorption

  9. A pre-concentration procedure using coprecipitation for determination of lead and iron in several samples using flame atomic absorption spectrometry

    OpenAIRE

    Ferreira, Sergio Luis Costa; Saracoglu, S.; Soylak, Mustafa; Peker, D. S. Kacar; Elci, L.; Santos, W. N. L. dos; Lemos, Valfredo Azevedo

    2006-01-01

    Texto completo: acesso restrito. p.133–137 The present paper proposes a pre-concentration procedure for determination of lead and iron in several samples by flame atomic absorption spectrometry. In it, lead(II) and iron(III) ions are coprecipitated using the violuric acid–copper(II) system as collector. Afterwards, the precipitate is dissolved with 1 M HNO3 solution and the metal ions are determined. The optimization step was performed using factorial design involving the variables: pH, v...

  10. Concentrations of arsenic, copper, cobalt, lead and zinc in cassava (Manihot esculenta Crantz) growing on uncontaminated and contaminated soils of the Zambian Copperbelt

    Science.gov (United States)

    Kříbek, B.; Majer, V.; Knésl, I.; Nyambe, I.; Mihaljevič, M.; Ettler, V.; Sracek, O.

    2014-11-01

    The concentrations of arsenic (As), copper (Cu), cobalt (Co), lead (Pb) and zinc (Zn) in washed leaves and washed and peeled tubers of cassava (Manihot esculenta Crantz, Euphorbiaceae) growing on uncontaminated and contaminated soils of the Zambian Copperbelt mining district have been analyzed. An enrichment index (EI) was used to distinguish between contaminated and uncontaminated areas. This index is based on the average ratio of the actual and median concentration of the given contaminants (As, Co, Cu, mercury (Hg), Pb and Zn) in topsoil. The concentrations of copper in cassava leaves growing on contaminated soils reach as much as 612 mg kg-1 Cu (total dry weight [dw]). Concentrations of copper in leaves of cassava growing on uncontaminated soils are much lower (up to 252 mg kg-1 Cu dw). The concentrations of Co (up to 78 mg kg-1 dw), As (up to 8 mg kg-1 dw) and Zn (up to 231 mg kg-1 dw) in leaves of cassava growing on contaminated soils are higher compared with uncontaminated areas, while the concentrations of lead do not differ significantly. The concentrations of analyzed chemical elements in the tubers of cassava are much lower than in its leaves with the exception of As. Even in strongly contaminated areas, the concentrations of copper in the leaves and tubers of cassava do not exceed the daily maximum tolerance limit of 0.5 mg kg-1/human body weight (HBW) established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The highest tolerable weekly ingestion of 0.025 mg kg-1/HBW for lead and the highest tolerable weekly ingestion of 0.015 mg kg-1/HBW for arsenic are exceeded predominantly in the vicinity of smelters. Therefore, the preliminary assessment of dietary exposure to metals through the consumption of uncooked cassava leaves and tubers has been identified as a moderate hazard to human health. Nevertheless, as the surfaces of leaves are strongly contaminated by metalliferous dust in the polluted areas, there is still a potential hazard

  11. Buccal mucosal delivery of a potent peptide leads to therapeutically-relevant plasma concentrations for the treatment of autoimmune diseases.

    Science.gov (United States)

    Jin, Liang; Boyd, Ben J; White, Paul J; Pennington, Michael W; Norton, Raymond S; Nicolazzo, Joseph A

    2015-02-10

    Stichodactyla helianthus neurotoxin (ShK) is an immunomodulatory peptide currently under development for the treatment of autoimmune diseases, including multiple sclerosis and rheumatoid arthritis by parenteral administration. To overcome the low patient compliance of conventional self-injections, we have investigated the potential of the buccal mucosa as an alternative delivery route for ShK both in vitro and in vivo. After application of fluorescent 5-Fam-ShK to untreated porcine buccal mucosa, there was no detectable peptide in the receptor chamber using an in vitro Ussing chamber model. However, the addition of the surfactants sodium taurodeoxycholate hydrate or cetrimide, and formulation of ShK in a chitosan mucoadhesive gel, led to 0.05-0.13% and 1.1% of the applied dose, respectively, appearing in the receptor chamber over 5h. Moreover, confocal microscopic studies demonstrated significantly enhanced buccal mucosal retention of the peptide (measured by mucosal fluorescence associated with 5-Fam-ShK) when enhancement strategies were employed. Administration of 5-Fam-ShK to mice (10mg/kg in a mucoadhesive chitosan-based gel (3%, w/v) with or without cetrimide (5%, w/w)) resulted in average plasma concentrations of 2.6-16.2nM between 2 and 6h, which were substantially higher than the pM concentrations required for therapeutic activity. This study demonstrated that the buccal mucosa is a promising administration route for the systemic delivery of ShK for the treatment of autoimmune diseases.

  12. Anesthetic Overdose Leading to Cardiac Arrest Diagnosed by End-Tidal Inhalant Concentration Analysis in a Dog

    Directory of Open Access Journals (Sweden)

    Erik Hofmeister

    2013-01-01

    Full Text Available A 5-year-old male-castrated Cocker Spaniel presented to the Veterinary Teaching Hospital of the University of Georgia for a total ear canal ablation. Premedication was with carprofen 2.2 mg/kg SQ, hydromorphone 0.1 mg/kg IM, diazepam 0.2 mg/kg IM, and glycopyrrolate 0.01 mg/kg IM. The patient was induced with lidocaine 2 mg/kg IV and etomidate 1 mg/kg IV and maintained with sevoflurane and a constant rate infusion consisting of lidocaine 0.05 mg/kg/min. Before surgery start, the patient’s systolic arterial blood pressure was 110 mmHg, heart rate (HR was 85 beats/min, respiratory rate was 8 breaths/min, end-tidal sevoflurane concentration was 3.2%, and end-tidal CO2 (ETCO2 was 23 mmHg. As a scrub was being performed, the patient’s HR abruptly dropped to 20 beats/min over the course of 2 minutes. His ETCO2 simultaneously decreased to 16 mmHg. At this time, cardiopulmonary arrest was diagnosed. After two minutes of resuscitation, a spontaneous heart beat was obtained and the patient was successfully recovered and discharged without further incident. The cardiac arrest in this case is most likely attributable to an overdose of inhalant anesthesia, which was diagnosed by an anesthetic inhalant concentration monitor. A gas analyzer may be a helpful contribution to the small animal practitioner, particularly those performing more lengthy or complex procedures.

  13. Use of a field portable X-Ray fluorescence analyzer to determine the concentration of lead and other metals in soil samples.

    Science.gov (United States)

    Clark, S; Menrath, W; Chen, M; Roda, S; Succop, P

    1999-01-01

    Field portable methods are often needed in risk characterization, assessment and management to rapidly determine metal concentrations in environmental samples. Examples are for determining: "hot spots" of soil contamination, whether dust wipe lead levels meet housing occupancy standards, and worker respiratory protection levels. For over 30 years portable X-Ray Fluorescence (XRF) analyzers have been available for the in situ, non-destructive, measurement of lead in paint. Recent advances made possible their use for analysis of airborne dust filter samples, soil, and dust wipes. Research at the University of Cincinnati with the NITON 700 Series XRF instrument (40 millicurie Cadmium 109 source, L X-Rays) demonstrated its proficiency on air sample filters (NIOSH Method No. 7702, "Lead by Field Portable XRF; limit of detection 6 microg per sample; working range 17-1,500 microg/m3 air). Research with lead dust wipe samples from housing has also shown promising results. This XRF instrument was used in 1997 in Poland on copper smelter area soil samples with the cooperation of the Wroclaw Medical Academy and the Foundation for the Children from the Copper Basin (Legnica). Geometric mean soil lead concentrations were 200 ppm with the portable XRF, 201 ppm with laboratory-based XRF (Kevex) and 190 ppm using atomic absorption (AA). Correlations of field portable XRF and AA results were excellent for samples sieved to less than 125 micrometers with R-squared values of 0.997, 0.957, and 0.976 for lead, copper and zinc respectively. Similarly, correlations were excellent for soil sieved to less than 250 micrometers, where R-squared values were 0. 924, 0.973, and 0.937 for lead, copper and zinc, respectively. The field portable XRF instrument appears to be useful for the determination of soil pollution by these metals in industrial regions.

  14. Effects of sub-lethal and chronic lead concentrations on blood and liver ALA-D activity and hematological parameters in Nile tilapia.

    Science.gov (United States)

    Dos Santos, Carlucio Rocha; Cavalcante, Ana Luiza Michel; Hauser-Davis, Rachel Ann; Lopes, Renato Matos; Mattos, Rita De Cássia Oliveira Da Costa

    2016-07-01

    Liver and blood δ-aminolevulinic acid dehydratase (ALA-D) inhibition by exposure to sub-lethal lead concentrations over time in Nile tilapia (Oreochromis niloticus) were investigated. All three lead concentrations (1mgkg(-1), 10mgkg(-1) and 100mgkg(-1)) significantly inhibited ALA-D activity in blood (319±29.2; 180±14.6 and 172±19µmols(-1)h(-1)L(-1) respectively) and liver (302±5.84; 201±41.4 and 93±22.1µmols(-1)h(-1)L(-1)) 24h after injection relative to controls (blood: 597±37.0µmols(-1)h(-1)L(-1); liver: 376±23.1µmols(-1)h(-1)L(-1)). Blood ALA-D was greatly inhibited in all but the highest lead dose. Fish were then exposed to 1mgkg(-1) lead for 9 days, and presented short-term hyperglycemia, decreased hemoglobin and hematocrit values and time-dependent blood ALA-D activity inhibition, corroborating blood ALA-D activity as being more suitable for investigating lead effects, showing dose and time-dependent ALA-D inhibition after lead exposure. The results of the present study also demonstrated that fish size affects blood ALA-D activity, as fish from the 24-h assay, which were slightly smaller (approximately 200g), showed higher ALA-D inhibition in response to lead exposure when compared to the fish from the 9-day assay (approximately 500g). Thus, fish size should always be taken into account both in the field and in laboratory settings, and efforts should be made to obtain uniform fish size samples for biomarker studies.

  15. Lead concentrations in Hymenolepis diminuta adults and Taenia taeniaeformis larvae compared to their rat hosts (Rattus norvegicus) sampled from the city of Cairo, Egypt.

    Science.gov (United States)

    Sures, B; Scheible, T; Bashtar, A R; Taraschewski, H

    2003-11-01

    Concentrations of lead, determined by electrothermal atomic absorption spectrometry, were compared between the cestodes Hymenolepis diminuta and Taenia taeniaeformis and its host rat (Rattus norvegicus). Rats were sampled at 2 sites, which differed in respect to lead pollution as quantified from road dust, adjacent to the city of Cairo, Egypt. Comparing lead levels among host tissues and the parasites the significantly highest accumulation was found in H. diminuta, followed by rat kidney and larvae of T. taeniaeformis. Calculation of bioconcentration factors showed that H. diminuta contained 36-, 29-, 6- and 6-fold higher lead levels than intestinal wall, liver, kidney and larvae of T. taeniaeformis, at the more polluted site. At the less contaminated site lead bioconcentration factors for H. diminuta were found to be 87, 87 and 11 referred to intestine, liver and kidney of the host. Due to a high variability of the lead concentrations in H. diminuta it was not possible to indicate differences in metal pollution between both sampling sites. This variability may be influenced by different age structures of cestode infrapopulations. It is likely that younger worms contain lower metal levels than older worms due to a shorter exposure period. Thus, it is necessary to standardize the sampling of worms which should be used for indication purposes. Due to a lack of adequate sentinel species in terrestrial habitats more studies are required to validate and standardize the use of helminths as accumulation bioindicators in order to obtain mean values with low standard deviations. The host-parasite system rat-H. diminuta appears to be a useful and promising bioindication system at least for lead in urban ecosystems as rats as well as the tapeworm are globally distributed and easily accessible.

  16. Relationships between thiamine content of eggs and concentrations of lead and other heavy metals in water and survival of Atlantic salmon fry

    Science.gov (United States)

    Ketola, H. George; Wedge, Leslie R.; Lary, Sandra J.; Grant, Edward C.; Rutzke, Michael A.; Wagenet, Linda P.; Eckhardt, David A.V.; Hairston, Nelson G.; Karig, Daniel E.; Yager, Richard

    2001-01-01

    Atlantic salmon (Salmo salar) were extirpated in much of New York state by the late 1800s. Currently, Atlantic salmon from Little Clear Pond (Saranac Lake, NY) are stocked in Cayuga Lake (Ithaca, NY) and Lake Ontario to support a fishery, but reproduction is severely impaired by thiamine deficiency in Cayuga Lake and probably in Lake Ontario--apparently caused by adults feeding on prey fish high in thiaminase. One study suggested that survival of these fry may be reduced by phosphorus, calcium, magnesium, copper, or lead in water. Thiamine deficiency is known to increase lead toxicity. Bringing gravid Atlantic salmon from Little Clear Pond and Cayuga Inlet into the laboratory, we examined the effect of exposing their fertilized eggs during water-hardening to water with and without added lead (0.1 to 100 mg lead·liter-1) and to other contaminated waters (from New York State) on the survival of their eggs and fry. Our results showed no significant influence of our water-hardening treatments on survival of eggs or fry; therefore, it appears that exposure of eggs (during water-hardening) to lead in water (concentrations up to 100 mg lead·liter-1) or to several contaminated waters was not detrimental to the survival of eggs or fry of Atlantic salmon. We also determined the mineral and heavy metal content of dried eggs and found that eggs from Cayuga Lake salmon had significantly higher concentrations of copper (1.9 vs. 0.5 mg·g-1) than did eggs from salmon from Little Clear Pond. All concentrations of copper appeared to be within the range observed in other normal salmon. There were no other significant differences in concentrations of other minerals tested. Concentrations of copper in Cayuga Lake water (mean, 1.16 mg·liter-1) were significantly higher than in Little Clear Pond water (mean, 0.17 mg·liter-1). The effect of copper in eggs of thiamine-deficient salmon is not known.

  17. High concentrations of lead and barium in hair of the rural population caused by water pollution in the Thar Jath oilfields in South Sudan.

    Science.gov (United States)

    Pragst, Fritz; Stieglitz, Klaus; Runge, Hella; Runow, Klaus-Dietrich; Quig, David; Osborne, Robert; Runge, Christian; Ariki, John

    2016-12-23

    In the oil fields of Thar Jath, South Sudan, increasing salinity of drinking water was observed together with human incompatibilities and rise in livestock mortalities. Hair analysis was used to characterize the toxic exposure of the population. Hair samples of volunteers from four communities with different distance from the center of the oil field (Koch 23km, n=24; Leer 50km, n=26; Nyal 110km, n=21; and Rumbek 220km, n=25) were analyzed for altogether 39 elements by inductively coupled plasma-mass spectrometry. Very high concentrations and a toxic health endangerment were assessed for lead and barium. The concentration of lead increased steadily with decreasing distance from the oil field from Rumbek (mean 2.8μg/g) to Koch (mean 18.7μg/g) and was there in the same range as in highly contaminated mining regions in Kosovo, China or Bolivia. The weighting materials in drilling muds barite (BaSO4) and galena (PbS) were considered to be the sources of drinking water pollution and high hair values. The high concentrations of lead and barium in hair demonstrate clearly the health risk caused by harmful deposition of toxic industrial waste but cannot be used for diagnosis of a chronic intoxication of the individuals.

  18. Concentration of copper, iron, zinc, cadmium, lead, and nickel in bull and ram semen and relation to the occurrence of pathological spermatozoa.

    Science.gov (United States)

    Massányi, P; Trandzik, J; Nad, P; Koreneková, B; Skalická, M; Toman, R; Lukac, N; Halo, M; Strapak, P

    2004-01-01

    In this study the concentration of copper, iron, zinc, cadmium, lead, and nickel in bull and ram semen and relation of these metals to spermatozoa morphology was investigated. Analysis by atomic absorption spectrophotometry showed that copper concentration was significantly higher (pzinc concentration was higher in bull semen in comparison with ram semen. The iron and cadmium concentrations in the semen were similar. Higher concentration of lead was found in ram semen. Higher levels of nickel were found in ram semen in comparison with bulls. In bull semen 11.79+/-4.88% of pathological spermatozoa was found. Higher occurrence of pathological spermatozoa was in ram semen (17.17+/-3.76) in comparison with the semen of bulls. Separated tail, tail torso, and knob twisted tail were the most frequent forms of pathological spermatozoa in both species. Correlation analysis in bulls showed high positive relation between iron and zinc (r = 0.72), nickel and separated tail (r = 0.76), separated tail and tail torso (r = 0.71), tail torso and total number of pathological spermatozoa (r=0.72), and between tail ball and total number of pathological spermatozoa (r = 0.78). In rams high positive correlation between cadmium and lead (r=0.98), nickel and separated tail (r=0.77), separated tail and total number of pathological spermatozoa (r=0.69), knob twisted tail and retention of cytoplasmic drop (r=0.78), and between knob twisted tail and other pathological spermatozoa (r = 0.71) was found. High negative correlation in ram semen was observed between copper and nickel (r=0.71), copper and separated tail (r=0.70), and between iron and tail torso (r=0.67). The results suggest that the studied metals have a direct effect on spermatozoa quality.

  19. Concentrations of lead, cadmium, mercury and other elements in seeds of Lupinus mutabilis and of other legumes.

    Science.gov (United States)

    Gross, R; Auslitz, J; Schramel, P; Payer, H D

    1987-01-01

    Several species of legumes and varieties of lupins were examined for their heavy metal content in the seeds. Atomic absorption spectrometry was the main analytical tool. Validity and reproducibility of the results was checked by analyzing the same materials at two different laboratories performing the same technique. Additionally, inductively coupled plasma emission spectroscopy was applied. In grains of Lupinus mutabilis which constitute a traditional food in Andean populations, the following contents of heavy metals were determined: 0.10-0.25 microgram/g Cd; 0.5-1.6 microgram/g Pb; 0.10-0.15 microgram/g Hg. Seeds of other legumes contained 0.05-0.35 microgram/g Cd; 0.1-0.2 microgram/g Pb; 0.01-0.04 microgram/g Hg. The high lead content of lupins is easily reduced to one tenth by traditional extraction with boiling water. The mercury content, too, is decreased by this technique. The high manganese content of 1 300-1,400 micrograms/g of Lupinus albus compared to other legumes (25-37 micrograms/g) seems to be characteristic for this species and may be of nutritional significance. The comparison of the heavy metal contents of legume seeds of different origin and variety indicates a complex pattern of environmental and genetic factors that contribute to the specific metal contents of individual harvests. On the level of varieties the environmental factors (climate, soil, geology, agricultural techniques) seem to exhibit more important influences on the specific accumulation of heavy metals than genetic factors. In contrast, on the level of species or genera, the accumulation of heavy metals seems to be dominated by genetic factors rather than by environmental influences.

  20. Concentrations of cadmium, Cobalt, Lead, Nickel, and Zinc in Blood and Fillets of Northern Hog Sucker (Hypentelium nigricans) from streams contaminated by lead-Zinc mining: Implications for monitoring

    Science.gov (United States)

    Schmitt, C.J.; Brumbaugh, W.G.; May, T.W.

    2009-01-01

    Lead (Pb) and other metals can accumulate in northern hog sucker (Hypentelium nigricans) and other suckers (Catostomidae), which are harvested in large numbers from Ozark streams by recreational fishers. Suckers are also important in the diets of piscivorous wildlife and fishes. Suckers from streams contaminated by historic Pb-zinc (Zn) mining in southeastern Missouri are presently identified in a consumption advisory because of Pb concentrations. We evaluated blood sampling as a potentially nonlethal alternative to fillet sampling for Pb and other metals in northern hog sucker. Scaled, skin-on, bone-in "fillet" and blood samples were obtained from northern hog suckers (n = 75) collected at nine sites representing a wide range of conditions relative to Pb-Zn mining in southeastern Missouri. All samples were analyzed for cadmium (Cd), cobalt (Co), Pb, nickel (Ni), and Zn. Fillets were also analyzed for calcium as an indicator of the amount of bone, skin, and mucus included in the samples. Pb, Cd, Co, and Ni concentrations were typically higher in blood than in fillets, but Zn concentrations were similar in both sample types. Concentrations of all metals except Zn were typically higher at sites located downstream from active and historic Pb-Zn mines and related facilities than at nonmining sites. Blood concentrations of Pb, Cd, and Co were highly correlated with corresponding fillet concentrations; log-log linear regressions between concentrations in the two sample types explained 94% of the variation for Pb, 73-83% of the variation for Co, and 61% of the variation for Cd. In contrast, relations for Ni and Zn explained <12% of the total variation. Fillet Pb and calcium concentrations were correlated (r = 0.83), but only in the 12 fish from the most contaminated site; concentrations were not significantly correlated across all sites. Conversely, fillet Cd and calcium were correlated across the range of sites (r = 0.78), and the inclusion of calcium in the fillet

  1. Determination of lead and cadmium concentration limits in agricultural soil and municipal solid waste compost through an approach of zero tolerance to food contamination.

    Science.gov (United States)

    Saha, Jayanta Kumar; Panwar, N R; Singh, M V

    2010-09-01

    Cadmium and lead are important environmental pollutants with high toxicity to animals and human. Soils, though have considerable metal immobilizing capability, can contaminate food chain via plants grown upon them when their built-up occurs to a large extent. Present experiment was carried out with the objective of quantifying the limits of Pb and Cd loading in soil for the purpose of preventing food chain contamination beyond background concentration levels. Two separate sets of pot experiment were carried out for these two heavy metals with graded levels of application doses of Pb at 0.4-150 mg/kg and Cd at 0.02-20 mg/kg to an acidic light textured alluvial soil. Spinach crop was grown for 50 days on these treated soils after a stabilization period of 2 months. Upper limit of background concentration levels (C(ul)) of these metals were calculated through statistical approach from the heavy metals concentration values in leaves of spinach crop grown in farmers' fields. Lead and Cd concentration limits in soil were calculated by dividing C(ul) with uptake response slope obtained from the pot experiment. Cumulative loading limits (concentration limits in soil minus contents in uncontaminated soil) for the experimental soil were estimated to be 170 kg Pb/ha and 0.8 kg Cd/ha. Based on certain assumptions on application rate and computed cumulative loading limit values, maximum permissible Pb and Cd concentration values in municipal solid waste (MSW) compost were proposed as 170 mg Pb/kg and 0.8 mg Cd/kg, respectively. In view of these limiting values, about 56% and 47% of the MSW compost samples from different cities are found to contain Pb and Cd in the safe range.

  2. A new insight to adsorption and accumulation of high lead concentration by exopolymer and whole cells of lead-resistant bacterium Acinetobacter junii L. Pb1 isolated from coal mine dump.

    Science.gov (United States)

    Kushwaha, Anamika; Rani, Radha; Kumar, Sanjay; Thomas, Tarence; David, Arun Alfred; Ahmed, Meraz

    2017-03-11

    A lead-resistant bacterial strain was isolated from coal mine dump and identified as Acinetobacter junii Pb1 on basis of 16S rRNA (ribosomal ribonucleic acid) gene sequencing. The minimum inhibitory concentration of lead for the strain was 16,000 mg l(-1) and it showed antibiotic and multi metal resistance. In aqueous culture, at an initial lead (Pb(II)) concentration of 100 and 500 mg l(-1), lead adsorption and accumulation by the isolate was 100 and 60%, at pH 7 at 30 °C after 48 and 120 h, respectively. The two fractions of exopolysaccharide (EPS), loosely associated EPS (laEPS) and bound EPS (bEPS), and whole cells (devoid of EPS) showed high binding affinity towards Pb(II). The binding affinity of laEPS towards Pb(II) (1071 mg Pb g(-1)) was three times higher than that of bEPS (321.5 mg Pb g(-1)) and 6.5 times higher than that of whole cells (165 mg Pb g(-1)). The binding affinity of EPS and whole cells with Pb(II), reported in the current study, is considerably higher as compared to that reported in the literature, till date. SEM analysis, showed an increase in thickness of cells on exposure to Pb(II) and TEM analysis, revealed its accumulation (interior of cell) and its adsorption (with the external cell surface). The isolate was also found to be positive for indole acetic acid (IAA) and 1-aminocyclopropane-1-carboxylate (ACC) deaminase production which helps in promoting plant growth. Thus, this study provides a new understanding towards Pb(II) uptake by A. junii Pb1, highlighting its potential on the restoration of Pb(II) contaminated repositories.

  3. Iron and/or zinc supplementation did not reduce blood lead concentrations in children in a randomized, placebo-controlled trial.

    Science.gov (United States)

    Rosado, Jorge L; López, Patricia; Kordas, Katarzyna; García-Vargas, Gonzalo; Ronquillo, Dolores; Alatorre, Javier; Stoltzfus, Rebecca J

    2006-09-01

    There is increasing interest in the interaction of nutritional deficiencies with toxic metals. Iron deficiency and elevated blood lead concentrations (PbB) reportedly occur together, and zinc also plays an important role in lead metabolism. The objective was to evaluate the effect of zinc and/or iron supplementation on PbB of children attending schools in the neighborhood of a smelter complex for 6 mo. We conducted a double-blind, placebo-controlled field trial in 9 elementary schools located within a 3.5-km radius of a metal foundry in Torreón, Mexico. Of the 602 first-graders enrolled, 517 completed supplementation and had initial and final PbBs. Children were given either 30 mg of iron, 30 mg of zinc, both, or a placebo daily for 6 mo. Baseline and final measures included nutritional status and PbB. The overall prevalence of iron and zinc deficiencies was 12.1 and 30.3%, respectively, and 10.3% were anemic. The PbB concentration decreased in all experimental groups (P < 0.05). After controlling for initial PbB, groups administered zinc and/or iron did not have lower PbB concentrations than the placebo group (P < 0.05). In conclusion, iron supplementation of lead-exposed children significantly improved iron status but did not reduce PbBs. Zinc supplementation did not reduce PbBs independently of zinc nutritional status. Neither iron nor zinc can be recommended as the sole treatment for lead-exposed school children.

  4. Effects of heavy metal (Pb) concentration on some growth parameters of plants grown in lead polluted soil under organic fertilizer amendment

    Institute of Scientific and Technical Information of China (English)

    Ojo M Oseni; Adekunle A Adelusi; Esther O Dada; Abdulfatai B Rufai

    2016-01-01

    This study investigated morphological variation and biomass accumulation that occurred inSida acuta andChromolaena odorata plants grown in lead polluted soil under organic fertilizer amendment. The study was carried out in the screen house at the Biological Gardens of the Obafemi Awolowo University, Ile-Ife, Osun State. The experiment was a factorial combination of one heavy metal (Pb) at five levels of concentration (0, 200, 400, 800 and 1,000 mg/kg) in a completely randomized design, and were replicated three times for each of the two plants and two levels (0 g/kg and 9.4 g/kg) of organic fertilizer (OBD-Plus). Each pot was filled with 5 kg of air-dried and sieved soil and placed on a plastic tray for the collection of excess water. Two weeks after planting, seedlings of uniform height were transplanted from the nursery to experimental pots at the rate of one seedling per pot and grown for 10 weeks. The growth parameters of the plants were biomonitored for 7 weeks. After 10 weeks of treatment, the plants were harvested and dried to calculate the biomass accumulation. The two plant species performed better under fertilizer application than without it. For each of the plant species the growth parameters decreased as the levels of Pb concentration increased. Furthermore, the plants' biomass decreased significantly (p<0.05) as the levels of Pb concentration increased. The organic fertilizer helped to improve the plants' performance in lead-polluted soil.

  5. Thermal lens study of thermo-optical properties and concentration quenching of Er{sup 3+}-doped lead pyrophosphate-based glasses

    Energy Technology Data Exchange (ETDEWEB)

    Santos, C. C. [Departamento de Fisica, CCET, Universidade Federal do Maranhao, 65085-580 Sao Luis-MA (Brazil); Rocha, U.; Vermelho, M. V. D.; Jacinto, C. [Grupo de Fotonica e Fluidos Complexos, Instituto de Fisica, Universidade Federal de Alagoas, 57072-970 Maceio, AL (Brazil); Guedes, I. [Departamento de Fisica, Universidade Federal do Ceara, Campus do PICI, Caixa Postal 6030, 60455-760 Fortaleza, CE (Brazil); Boatner, L. A. [ORNL Center for Radiation Detection Materials and Systems and ORNL Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6044 (United States)

    2012-06-15

    In this work, we have used the thermal lens technique combined with conventional spectroscopy to characterize the thermo-optical properties of Er{sup 3+}-doped lead pyrophosphate-based glasses. More precisely, we have investigated and quantified experimentally the fluorescence quantum efficiencies of the Er{sup 3+} levels, and we describe the role of concentration quenching effects. The fluorescence quantum efficiency of the {sup 4}I{sub 13/2} level is very high when compared to other phosphate glasses, while that of the green-coupled levels is very small. Other important photonic materials parameters, such as the thermal diffusivity and temperature coefficient of the optical path length change, were obtained and compared with those of other glass systems. The cumulative results obtained here for the Er-doped lead pyrophosphate glass show that this material is a good candidate for photonic applications with a characteristic Er{sup 3+} infrared emission around 1550 nm.

  6. Study on Chlorination Leaching New Technology for Lead Sulphide Concentrate%硫化铅精矿氯化浸出新工艺研究

    Institute of Scientific and Technical Information of China (English)

    李淑梅; 张福生; 丛自范

    2011-01-01

    研究了硫化铅精矿在盐酸-氧气体系中的氯化浸出过程.重点考察了各种参数对硫化铅精矿中铅和银浸出效果和硫在浸出渣中富集率的影响.结果表明,硫化铅精矿在氯化镁溶液中的浸出效果优于氯化钠溶液,在催化剂铜离子浓度为1.45 g/L、盐酸用量为理论量1.5倍、氧气流量40 mL/min、氯化镁浓度5.5 mol/L、浸出温度90℃、浸出时间7h、液固比6∶1的条件下,铅和银的浸出率分别达到99.11%和90.57%,硫富集率为90.12%.%Chlorination leaching process of lead sulphide concentrate in hydrochloric acid-oxygen system was studied. A variety of parameters on the effect of lead and silver leaching rate and enriching rate of sulfur in leaching residue were investigated. The results indicate that the leaching effect of lead sulphide concentrate in magnesium chloride solution is superior to that in sodium chloride solution. Lead and silver leaching rate achieved 99. 11%, 90. 57% respectively, and enriching rate of sulphur is 90. 12% under the optimum parameters that catalyst copper ion concentration is 1. 45 g/L, hydrochloric acid dosage is 1. 5 times to theoretical quantity, oxygen flow is 40 mL/min, magnesium chloride concentration is 5. 5 mol/L, leaching temperature is 90 ℃ , leaching time is 7 hours, ratio of liquid to solid is 6 : 1.

  7. Associations between soil lead concentrations and populations by race/ethnicity and income-to-poverty ratio in urban and rural areas.

    Science.gov (United States)

    Aelion, C Marjorie; Davis, Harley T; Lawson, Andrew B; Cai, Bo; McDermott, Suzanne

    2013-02-01

    Lead (Pb) is a well-studied environmental contaminant that has many negative health effects, especially for children. Both racial/ethnic and income disparities have been documented with respect to exposure to Pb in soils. The objectives of this study were to assess whether soil Pb concentrations in rural and urban areas of South Carolina USA, previously identified as having clusters of intellectual disabilities (ID) in children, were positively associated with populations of minority and low-income individuals and children (≤ 6 years of age). Surface soils from two rural and two urban areas with identified clusters of ID were analyzed for Pb and concentrations were spatially interpolated using inverse distance weighted analysis. Population race/ethnicity and income-to-poverty ratio (ITPR) from United States Census 2000 block group data were aerially interpolated by block group within each area. Urban areas had significantly higher concentrations of Pb than rural areas. Significant positive associations between black, non-Hispanic Latino, individuals and children ≤ 6 years of age and mean estimated Pb concentrations were observed in both urban (r = 0.38, p = 0.0007) and rural (r = 0.53, p = 0.04) areas. Significant positive associations also were observed between individuals and children with an ITPR urban areas. Racial/ethnic minorities and low ITPR individuals, including children, may be at elevated risk for exposure to Pb in soils.

  8. The associations among semen quality, oxidative DNA damage in human spermatozoa and concentrations of cadmium, lead and selenium in seminal plasma.

    Science.gov (United States)

    Xu, De-Xiang; Shen, Han-Ming; Zhu, Qi-Xing; Chua, Laiha; Wang, Qu-Nan; Chia, Sin-Eng; Ong, Choon-Nam

    2003-01-10

    To explore the associations among semen quality, oxidative DNA damage in human spermatozoa and concentrations of cadmium, lead and selenium in seminal plasma, 56 non-smoking subjects were asked to collect semen by masturbation into a sterile wide-mouth metal-free plastic container after 3 days of abstinence. The conventional semen parameters were analysed. The concentrations of Cd, Pb and Se in seminal plasma were detected using atomic absorption spectrophotometer. 8-OHdG levels in sperm DNA were measured using HPLC-EC. The results showed that the geometric mean concentrations of Cd, Pb and Se were 0.78, 7.8 and 51.4 microg/l, respectively. The geometric mean of 8-OHdG/10(6) dG was 51.4 (95% CI: 21.5-123.0). A significant inverse correlation exists between Cd and sperm density (r=-0.28, Pspermatozoa. Se could protect against oxidative DNA damage in human sperm cells. Pb did not appear to have any association with the semen quality when concentration of Pb in seminal plasma was below 10 microg/l.

  9. Assessing the Influence of Age and Ethnicity on the Association Between Iron Status and Lead Concentration in Blood: Results from the Canadian Health Measures Survey (2007-2011).

    Science.gov (United States)

    Ngueta, Gerard

    2016-06-01

    Inverse association has been reported between iron intake and blood lead concentration (PbB) in epidemiological studies. Data on this association at a low dose of lead exposure are scarce, and the potential influence of ethnicity and age has not been previously reported. This study aimed to estimate the relation between serum ferritin, haemoglobin, haematocrit, and mean corpuscular volume and PbB among 6-18-year-old individuals. Data from Canadian Health and Measures Survey (CHMS), cycle 1 (2007-2009) and cycle 2 (2009-2011), were accessed. A household interview followed by a physical examination (including collection of blood) was performed. The quantification of lead and trace elements in blood was performed by inductively coupled plasma mass spectrometry. The mean PbB was 0.79 μg/dL (95 % confidence interval (95 % CI) 0.75-0.82). Except for haemoglobin levels, no association was found between PbB and any of the parameters of iron status, independently of age. A significant interaction was observed between ferritin levels and ethnicity in relation to PbB (p = 0.07). We found a little evidence of an association between iron status and PbB in the whole sample of subjects aged 6-18 years exposed to low levels of environmental lead. The significant interaction observed between ferritin levels and ethnicity in relation to BPb suggests that the influence of ferritin levels on lead uptake may change by ethnicity, even at low exposure.

  10. Lead, cadmium, and zinc concentrations in plaster and mortar from structures in Jasper and Newton Counties, Missouri (Tri-State Mining District).

    Science.gov (United States)

    Perry, Phyllis M; Pavlik, Jeffrey W; Sheets, Ralph W; Biagioni, Richard N

    2005-01-05

    The primary goal of this study was to evaluate anecdotal evidence that within Jasper and Newton Counties, Missouri, two counties within the Tri-State Mining District, granular mine tailings were commonly used in place of river sands in wall plasters and mortar. Interior wall plaster and mortar samples from structures in this mining district were analyzed for lead, cadmium, and zinc, and compared to samples from Springfield, MO (comparison site). The Jasper and Newton County samples showed elevated concentrations of the three elements, consistent with the inclusion of mine tailings, with a number of samples containing lead and cadmium at concentrations greater than EPA remediation targets for yard soil. X-ray diffraction studies showed the presence of the zinc ore minerals, sphalerite and hemimorphite, in high level samples. Thin section optical studies identified the major component of the aggregate as chert, a mineral abundant within the tailing piles. Because dust from crumbling plaster and mortar could represent an avenue for significant heavy metal exposure to building occupants, we suggest that there may be associated health consequences that should be further evaluated.

  11. Lead, cadmium, and zinc concentrations in plaster and mortar from structures in Jasper and Newton Counties, Missouri (Tri-State Mining District)

    Energy Technology Data Exchange (ETDEWEB)

    Perry, Phyllis M. [Chemistry Department, Southwest Missouri State University, 901 S. National Avenue, Springfield, MO 65804 (United States); Pavlik, Jeffrey W. [Chemistry Department, Southwest Missouri State University, 901 S. National Avenue, Springfield, MO 65804 (United States); Sheets, Ralph W. [Chemistry Department, Southwest Missouri State University, 901 S. National Avenue, Springfield, MO 65804 (United States); Biagioni, Richard N. [Chemistry Department, Southwest Missouri State University, 901 S. National Avenue, Springfield, MO 65804 (United States)]. E-mail: rnb266f@smsu.edu

    2005-01-05

    The primary goal of this study was to evaluate anecdotal evidence that within Jasper and Newton Counties, Missouri, two counties within the Tri-State Mining District, granular mine tailings were commonly used in place of river sands in wall plasters and mortar. Interior wall plaster and mortar samples from structures in this mining district were analyzed for lead, cadmium, and zinc, and compared to samples from Springfield, MO (comparison site). The Jasper and Newton County samples showed elevated concentrations of the three elements, consistent with the inclusion of mine tailings, with a number of samples containing lead and cadmium at concentrations greater than EPA remediation targets for yard soil. X-ray diffraction studies showed the presence of the zinc ore minerals, sphalerite and hemimorphite, in high level samples. Thin section optical studies identified the major component of the aggregate as chert, a mineral abundant within the tailing piles. Because dust from crumbling plaster and mortar could represent an avenue for significant heavy metal exposure to building occupants, we suggest that there may be associated health consequences that should be further evaluated.

  12. [Effects of Different Modifier Concentrations on Lead-Zinc Tolerance, Subcellular Distribution and Chemical Forms for Four Kinds of Woody Plants].

    Science.gov (United States)

    Chen, Yong-hua; Zhang, Fu-yun; Wu, Xiao-fu; Liang, Xi; Yuan, Si-wen

    2015-10-01

    Four kinds of lead-zinc tolerant woody plants: Nerium oleander, Koelreuteria paniculata, Paulownia and Boehmeria were used as materials to estimate their enrichment and transferable capacity of lead (Pb) and zinc (Zn) and analyze the subcellular distribution and chemical speciation of Zn and Ph in different parts of plants, under different modifier concentrations (CK group: 100% lead-zinc slag plus a small amount of phosphate fertilizer, improved one: 85% of lead-zinc slag ± 10% peat ± 5% bacterial manure plus a small amount of phosphate fertilizer, improved two: 75% lead-zinc slag ± 20% peat ± 5% bacterial manure ± a small amount of phosphate). Results showed that: (1) The content of Pb, Zn in matrix after planting four kinds of plants was lower than before, no significant difference between improved one and improved two of Nerium oleander and Boehmeria was found, but improved two was better than improved one of Paulownia, while improved one was better than improved two of Koelreuteria paniculata; Four plants had relatively low aboveground enrichment coefficient of Pb and Zn, but had a high transfer coefficient, showed that the appropriate modifier concentration was able to improve the Pb and Zn enrichment and transfer ability of plants. (2) In subcellular distribution, most of Pb and Zn were distributed in plant cell wall components and soluble components while the distribution in cell organelles such as mitochondria, chloroplasts and nucleus component were less. Compared with CK group, two improved group made soluble components of the cell walls of Pb fixation and retention of zinc role in the enhancement. (3) As for the chemical forms of Pb and Zn in plants, the main chemical forms of Pb were hydrochloric acid, sodium chloride and ethanol extractable forms, while other chemical form contents were few, the main chemical forms of Zn were different based on plant type. Compared with CK group, the proportion of the active Pb chemical form in different plant

  13. Tissue transglutaminase treatment leads to concentration-dependent changes in dendritic cell phenotype - implications for the role of transglutaminase in coeliac disease

    Directory of Open Access Journals (Sweden)

    Dalleywater William J

    2012-04-01

    Full Text Available Abstract Dendritic cells (DCs are part of the innate immune system with a key role in initiating and modulating T cell mediated immune responses. Coeliac disease is caused by inappropriate activation of such a response leading to small intestinal inflammation when gluten is ingested. Tissue transglutaminase, an extracellular matrix (ECM protein, has an established role in coeliac disease; however, little work to date has examined its impact on DCs. The aim of this study was to investigate the effect of small intestinal ECM proteins, fibronectin (FN and tissue transglutaminase 2 (TG-2, on human DCs by including these proteins in DC cultures. The study used flow cytometry and scanning electron microscopy to determine the effect of FN and TG-2 on phenotype, endocytic ability and and morphology of DCs. Furthermore, DCs treated with FN and TG-2 were cultured with T cells and subsequent T cell proliferation and cytokine profile was determined. The data indicate that transglutaminase affected DCs in a concentration-dependent manner. High concentrations were associated with a more mature phenotype and increased ability to stimulate T cells, while lower concentrations led to maintenance of an immature phenotype. These data provide support for an additional role for transglutaminase in coeliac disease and demonstrate the potential of in vitro modelling of coeliac disease pathogenesis.

  14. Canadian House Dust Study: Population-based concentrations, loads and loading rates of arsenic, cadmium, chromium, copper, nickel, lead, and zinc inside urban homes

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Pat E. [Exposure and Biomonitoring Division, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON, Canada K1A 0K9 (Canada); Department of Earth Sciences, University of Ottawa, 140 Louis Pasteur, Ottawa, ON, Canada K1N 6N5 (Canada); Levesque, Christine [Exposure and Biomonitoring Division, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON, Canada K1A 0K9 (Canada); Chénier, Marc; Gardner, H. David [Exposure and Biomonitoring Division, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON, Canada K1A 0K9 (Canada); Department of Earth Sciences, University of Ottawa, 140 Louis Pasteur, Ottawa, ON, Canada K1N 6N5 (Canada); Jones-Otazo, Heather [Regions and Programs Branch, Health Canada, 180 Queen Street West, Toronto, ON, Canada M5V 3L7 (Canada); Petrovic, Sanya [Contaminated Sites Division, Healthy Environments and Consumer Safety Branch, Health Canada, 269 Laurier Ave West, Ottawa, ON, Canada K1A 0K9 (Canada)

    2013-01-15

    The Canadian House Dust Study was designed to obtain nationally representative urban house dust metal concentrations (μg g{sup −1}) and metal loadings (μg m{sup −2}) for arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn). Consistent sampling of active dust of known age and provenance (area sampled) also permitted the calculation of indoor loading rates (mg m{sup −2} day{sup −1} for dust and μg m{sup −2} day{sup −1} for metals) for the winter season (from 2007 to 2010) when houses are most tightly sealed. Geomean/median indoor dust loading rates in homes located more than 2 km away from industry of any kind (9.6/9.1 mg m{sup −2} day{sup −1}; n = 580) were significantly lower (p < .001) than geomean (median) dust loading rates in homes located within 2 km of industry (13.5/13.4 mg m{sup −2} day{sup −1}; n = 421). Proximity to industry was characterized by higher indoor metal loading rates (p < .003), but no difference in dust metal concentrations (.29 ≥ p ≤ .97). Comparisons of non-smokers' and smokers' homes in non-industrial zones showed higher metal loading rates (.005 ≥ p ≤ .038) in smokers' homes, but no difference in dust metal concentrations (.15 ≥ p ≤ .97). Relationships between house age and dust metal concentrations were significant for Pb, Cd and Zn (p < .001) but not for the other four metals (.14 ≥ p ≤ .87). All seven metals, however, displayed a significant increase in metal loading rates with house age (p < .001) due to the influence of higher dust loading rates in older homes (p < .001). Relationships between three measures of metals in house dust – concentration, load, and loading rate – in the context of house age, smoking behavior and urban setting consistently show that concentration data is a useful indicator of the presence of metal sources in the home, whereas dust mass is the overriding influence on metal loadings and loading rates

  15. (Lead concentration in the blood and aminolevulinic acid dehydratase (ALAD) activity in the erythrocytes depending on sex, age, tobacco smoking and alcohol drinking in the group of persons exposed to industrial dust)

    Energy Technology Data Exchange (ETDEWEB)

    Kuliczkowski, K.

    1981-01-01

    A population of 399 persons (180 women and 219 men) has been examined. Anamnesis included detailed inquiries about smoking habit and alcohol drinking. In the laboratory, lead concentration in blood and ALAD activity in erythrocytes have been determined on empty stomach. No differences have been found in the mean lead concentration determined by sex, whereas the mean ALAD activity is higher in women than in men. The subjects' age has affected the test parameters neither in men nor women. In smoking men no changes in the mean lead concentration in blood and mean ALAD activity in erythrocytes have been found. In smoking women, the mean lead concentration is not changed, but the mean ALAD activity is lower. Alcohol drinking in men does not change the values of the test parameters, whereas drinking women have revealed higher mean blood lead concentration.

  16. Interactions between cadmium and lead with acidic soils: Experimental evidence of similar adsorption patterns for a wide range of metal concentrations and the implications of metal migration

    Energy Technology Data Exchange (ETDEWEB)

    Pokrovsky, O.S. [GET-CNRS-UPS-IRD-UMR 5563, 14, Avenue Edouard Belin, 31400 Toulouse (France); Probst, A., E-mail: anne.probst@ensat.fr [Universite de Toulouse, INPT, UPS, EcoLab (Laboratoire Ecologie fonctionnelle et Environnement), ENSAT, Avenue de l' Agrobiopole, 31326 Castanet-Tolosan (France); CNRS, EcoLab, 31326 Castanet-Tolosan (France); Leviel, E. [GET-CNRS-UPS-IRD-UMR 5563, 14, Avenue Edouard Belin, 31400 Toulouse (France); Liao, B. [International College, Central South University of Forestry and Technology, Changsha 410004 (China)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Adsorption experiments of Cd and Pb in acid soils (China, France). Black-Right-Pointing-Pointer Large pH conditions and large range of metal concentrations were considered. Black-Right-Pointing-Pointer Similar dependencies between metals concentration in solution and metal adsorbed on the surface were predicted using Langmuir and Freundlich equations and surface complexation model (SCM). Black-Right-Pointing-Pointer No competition between Cd and Pb detected at pH 5. Black-Right-Pointing-Pointer Metal adsorption capacity is two orders of magnitude higher than limit value for soil protection. - Abstract: The importance of high- and low-affinity surface sites for cadmium and lead adsorption in typical European and Asian soils was investigated. Adsorption experiments on surface and deep horizons of acidic brown (Vosges, France) and red loess soils (Hunan, China) were performed at 25 Degree-Sign C as a function of the pH (3.5-8) and a large range of metal concentrations in solution (10{sup -9}-10{sup -4} mol l{sup -1}). We studied the adsorption kinetics using a Cd{sup 2+}-selective electrode and desorption experiments as a function of the solid/solution ratio and pH. At a constant solution pH, all samples exhibited similar maximal adsorption capacities (4.0 {+-} 0.5 {mu}mol/g Cd and 20 {+-} 2 {mu}mol/g Pb). A constant slope of adsorbed-dissolved concentration dependence was valid over 5 orders of magnitude of metal concentrations. Universal Langmuir and Freundlich equations and the SCM formalism described the adsorption isotherms and the pH-dependent adsorption edge over very broad ranges of metal concentrations, indicating no high- or low-affinity sites for metal binding at the soil surface under these experimental conditions. At pH 5, Cd and Pb did not compete, in accordance with the SCM. The metal adsorption ability exceeded the value for soil protection by two orders of magnitude, but only critical load guarantees soil

  17. Chronic Effects of Realistic Concentrations of Non-essential and Essential Metals (Lead and Zinc) on Oxidative Stress Biomarkers of the Mosquitofish, Gambusia holbrooki.

    Science.gov (United States)

    Nunes, Bruno; Caldeira, Carina; Luísa Pereira, Joana; Gonçalves, Fernando; Correia, Alberto Teodorico

    2015-11-01

    Metallic contamination is widespread, particularly in areas impacted by human activities. Human activities result in high loads of metals being discarded into the aquatic compartment, reinforcing the need to evaluate their toxic effects especially on exposed fish. The purpose of this study was to determine the toxic response (namely, antioxidant levels and lipoperoxidative damage) in both liver and gills of the freshwater fish species Gambusia holbrooki, exposed to lead and zinc. Fish were exposed for 28 days (chronic exposure) to ecologically relevant concentrations of the selected compounds. The following oxidative stress/damage biomarkers were evaluated: glutathione-S-transferases (GSTs), glutathione reductase (GR), and thiobarbituric acid reactive substances (TBARS). The results indicate that lead caused a significant oxidative response, with significant increase of the enzymatic antioxidant defense (GSTs activity in hepatic tissue, and GR activity in branchial tissue) of exposed organisms. On the other hand, zinc caused a significant inhibition of G. holbrooki hepatic GR, a biological response that may be related to the antioxidant activity exhibited by this metal. The obtained results are of high importance, especially if one considers that the obtained toxic responses occurred at low, albeit ecologically relevant, levels of exposure.

  18. Determination of trace element concentrations and stable lead, uranium and thorium isotope ratios by quadrupole-ICP-MS in NORM and NORM-polluted sample leachates.

    Science.gov (United States)

    Mas, J L; Villa, M; Hurtado, S; García-Tenorio, R

    2012-02-29

    This work focuses on the monitoring of the potential pollution in scenarios that involve NORM-related industrial activities (environmental or in-door scenarios). The objective was to develop a method to determine extent and origin of the contamination, suitable for monitoring (i.e. simple, fast and economical) and avoiding the use of too many different instruments. It is presented a radiochemical method that allows the determination of trace element concentrations and 206Pb/207Pb/208Pb, 238U/234U and 232Th/230Th isotope ratios using a single sample aliquot and a single instrument (ICP-QMS). Eichrom UTEVA® extraction chromatography minicolumns were used to separate uranium and thorium in sample leachates. Independent ICP-MS determinations of uranium and thorium isotope ratios were carried out afterwards. Previously a small aliquot of the leachate was used for the determination of trace element concentrations and lead isotope ratios. Several radiochemical arrangements were tested to get maximum performances and simplicity of the method. The performances of the method were studied in terms of chemical yields of uranium and thorium and removal of the potentially interfering elements. The established method was applied to samples from a chemical industry and sediments collected in a NORM-polluted scenario. The results obtained from our method allowed us to infer not only the extent, but also the sources of the contamination in the area. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. 重选金铅精矿回收金银工艺研究%Recovery technology of gold and silver from gold-lead gravity concentrate

    Institute of Scientific and Technical Information of China (English)

    简椿林

    2014-01-01

    以某重选金铅精矿为研究对象,研究了提高金银回收率的工艺.研究发现:“摇床富集-精矿火法熔炼-尾矿氰化”工艺能有效回收金银.金精矿摇床试验金和银的回收率分别为89.43%和74.07%.金精矿摇床试验得到的精矿经过火法熔炼,金和银的回收率分别达到99.98%和99.95%;摇床尾矿不经磨矿直接氰化,pH值10~11,NaCN浓度1‰,矿浆浓度50%,浸出24 h,渣中金和银的品位分别降低到6.33 g/t,金和银的浸出率分别达到98.97%和55.94%,NaCN耗量为6.03 kg/t.%Technology of recovery gold and silver is studied to improve recovery ratio from gold-lead gravity concentrate. The results show that the technology of tabling concentration - melting of tabling concentrate -cyaniding of tabling tailing is effective on recovery gold and silver. The recovery ratio of gold and silver on tabling experiment are 89.43 % and 74.07 %, respectively. The recovery ratio of gold and silver on smelting experiment are 99.98%and 99.95%, respectively. Under the condition of pH 10~11, concentration of NaCN 1 ‰, mud concentration 10%, time 24 h, gold and silver in slag of leaching can decrease to 6.33 g /t and 339.6 g /t, respectively. The recovery ratio of gold and silver on leaching experiment are 98.97 % and 55.94 %, respectively. The consumption of NaCN is 6.03 kg/t.

  20. Determination of trace element concentrations and stable lead, uranium and thorium isotope ratios by quadrupole-ICP-MS in NORM and NORM-polluted sample leachates

    Energy Technology Data Exchange (ETDEWEB)

    Mas, J.L., E-mail: ppmasb@us.es [Dpto. Fisica Aplicada I, EPS, Universidad de Sevilla, 41012 Sevilla (Spain); Villa, M. [Servicio de Radioisotopos, Centro de Investigacion, Tecnologia e Innovacion (CITIUS), Universidad de Sevilla, Avda. Reina Mercedes 4b, 41012 Sevilla (Spain); Dpto. Fisica Aplicada II, ETS de Arquitectura, Universidad de Sevilla, Avda. Reina Mercedes 2, 41012 Sevilla (Spain); Hurtado, S. [Servicio de Radioisotopos, Centro de Investigacion, Tecnologia e Innovacion (CITIUS), Universidad de Sevilla, Avda. Reina Mercedes 4b, 41012 Sevilla (Spain); Garcia-Tenorio, R. [Dpto. Fisica Aplicada II, ETS de Arquitectura, Universidad de Sevilla, Avda. Reina Mercedes 2, 41012 Sevilla (Spain)

    2012-02-29

    Highlights: Black-Right-Pointing-Pointer Polluted sediment and NORM samples. Black-Right-Pointing-Pointer An efficient yet fast process allowing multi-parametric determinations in <3 days. Black-Right-Pointing-Pointer Trace element concentrations, Pb, Th and U isotope ratios with a single instrument. - Abstract: This work focuses on the monitoring of the potential pollution in scenarios that involve NORM-related industrial activities (environmental or in-door scenarios). The objective was to develop a method to determine extent and origin of the contamination, suitable for monitoring (i.e. simple, fast and economical) and avoiding the use of too many different instruments. It is presented a radiochemical method that allows the determination of trace element concentrations and {sup 206}Pb/{sup 207}Pb/{sup 208}Pb, {sup 238}U/{sup 234}U and {sup 232}Th/{sup 230}Th isotope ratios using a single sample aliquot and a single instrument (ICP-QMS). Eichrom UTEVA{sup Registered-Sign} extraction chromatography minicolumns were used to separate uranium and thorium in sample leachates. Independent ICP-MS determinations of uranium and thorium isotope ratios were carried out afterwards. Previously a small aliquot of the leachate was used for the determination of trace element concentrations and lead isotope ratios. Several radiochemical arrangements were tested to get maximum performances and simplicity of the method. The performances of the method were studied in terms of chemical yields of uranium and thorium and removal of the potentially interfering elements. The established method was applied to samples from a chemical industry and sediments collected in a NORM-polluted scenario. The results obtained from our method allowed us to infer not only the extent, but also the sources of the contamination in the area.

  1. Mapping Copper and Lead Concentrations at Abandoned Mine Areas Using Element Analysis Data from ICP-AES and Portable XRF Instruments: A Comparative Study.

    Science.gov (United States)

    Lee, Hyeongyu; Choi, Yosoon; Suh, Jangwon; Lee, Seung-Ho

    2016-03-30

    Understanding spatial variation of potentially toxic trace elements (PTEs) in soil is necessary to identify the proper measures for preventing soil contamination at both operating and abandoned mining areas. Many studies have been conducted worldwide to explore the spatial variation of PTEs and to create soil contamination maps using geostatistical methods. However, they generally depend only on inductively coupled plasma atomic emission spectrometry (ICP-AES) analysis data, therefore such studies are limited by insufficient input data owing to the disadvantages of ICP-AES analysis such as its costly operation and lengthy period required for analysis. To overcome this limitation, this study used both ICP-AES and portable X-ray fluorescence (PXRF) analysis data, with relatively low accuracy, for mapping copper and lead concentrations at a section of the Busan abandoned mine in Korea and compared the prediction performances of four different approaches: the application of ordinary kriging to ICP-AES analysis data, PXRF analysis data, both ICP-AES and transformed PXRF analysis data by considering the correlation between the ICP-AES and PXRF analysis data, and co-kriging to both the ICP-AES (primary variable) and PXRF analysis data (secondary variable). Their results were compared using an independent validation data set. The results obtained in this case study showed that the application of ordinary kriging to both ICP-AES and transformed PXRF analysis data is the most accurate approach when considers the spatial distribution of copper and lead contaminants in the soil and the estimation errors at 11 sampling points for validation. Therefore, when generating soil contamination maps for an abandoned mine, it is beneficial to use the proposed approach that incorporates the advantageous aspects of both ICP-AES and PXRF analysis data.

  2. Progress on the development of H-concentration probes in eutectic lead-lithium: Synthesis and characterization of electrochemical sensor materials

    Energy Technology Data Exchange (ETDEWEB)

    Llivina, L.; Colominas, S. [Universitat Ramon Llull, ETS Institut Quimic de Sarria, Electrochemical Methods Laboratory - Analytical Chemistry Department Via Augusta, 390, 08017 Barcelona (Spain); Reyes, G. [Universitat Ramon Llull, ETS Institut Quimic de Sarria, Industrial Engineering Department, Via Augusta, 390, 08017 Barcelona (Spain); Abella, J., E-mail: jordi.abella@iqs.es [Universitat Ramon Llull, ETS Institut Quimic de Sarria, Electrochemical Methods Laboratory - Analytical Chemistry Department Via Augusta, 390, 08017 Barcelona (Spain)

    2012-08-15

    Dynamic tritium concentration measurement in lithium-lead eutectic (17% Li-83% Pb) is of major interest for a reliable tritium testing program in ITER TBM and for an experimental proof of tritium self-sufficiency in liquid metal breeding systems. Potentiometric hydrogen sensors for molten lithium-lead eutectic have been designed at the Electrochemical Methods Lab at Institut Quimic de Sarria (IQS) at Barcelona and are under development and qualification. The probes are based on the use of solid state electrolytes and works as Proton Exchange Membranes (PEM). In this work, the following compounds have been synthesized in order to be tested as PEM H-probes: BaCeO{sub 3}, BaCe{sub 0.9}Y{sub 0.1}O{sub 3-{delta}}, SrCe{sub 0.9}Y{sub 0.1}O{sub 3-{delta}} and Sr(Ce{sub 0.9}-Zr{sub 0.1}){sub 0.95}Yb{sub 0.05}O{sub 3-{delta}}. Potentiometric measurements of the synthesized ceramic elements have been performed at different hydrogen concentrations at 500 Degree-Sign C. In this campaign, a fixed and known hydrogen pressure has been used in the reference electrode. The sensors constructed using the proton conductor elements BaCeO{sub 3}, SrCe{sub 0.9}Y{sub 0.1}O{sub 3-{delta}} and Sr(Ce{sub 0.9}-Zr{sub 0.1}){sub 0.95}Yb{sub 0.05}O{sub 3-{delta}} exhibited quite stable output potential and its value was quite close to the theoretical value calculated with the Nernst equation (deviation less than 100 mV). Unstable measurement was obtained using BaCe{sub 0.9}Y{sub 0.1}O{sub 3-{delta}} as a solid state electrolyte in the sensor.

  3. 利用硝酸回收机械化学活化后的硫化物浓缩液中的铅%Recovery of Lead from Sulfide Concentrate after Mechanochemical Activation Using Nitric Acid

    Institute of Scientific and Technical Information of China (English)

    A.G. Kholmogorov; O.N. Kononova; G.L. Pashkov; L.V. Shashina; V.P. Plekhanov; A.A. Sabetskiy

    2005-01-01

    Decomposition of lead sulfide concentrates in nitric acidic solutions after ferric (Ⅲ) nitrate addition and mechanical preparation has been investigated. It was found out that the decomposition can be achieved in of mechanochemical activation. The use of [Fe(NO3)3-HNO3-H2O] aqueous salt system allows the decomposition of lead sulfide concentrate at room temperature and in this case the concentration of HNO3 does not exceed mechanochemical activation of this concentrate. The insoluble residues after the leaching contain SiO2, S0, FeCO3 and PbSO4.

  4. Differential changes in serum uric acid concentrations in sibutramine promoted weight loss in diabetes: results from four weeks of the lead-in period of the SCOUT trial

    Directory of Open Access Journals (Sweden)

    Caterson Ian D

    2009-10-01

    Full Text Available Abstract Background and aims Elevated levels of serum uric acid are associated with an increased risk of cardiovascular morbidity and mortality. The response of uric acid to weight loss therapy (lifestyle plus sibutramine in an overweight and obese cardiovascular high risk population was studied. Methods and results Data from a four week single-blind lead-in period of the Sibutramine Cardiovascular OUTcomes (SCOUT study were analyzed. 2584 patients (24% had diabetes mellitus (DM only, 1748 (16% had cardiovascular disease (CVD only and 6397 (60% had both DM + CVD. Uric acid concentrations (mean ± standard deviation at screening were significantly higher among patients with CVD compared to patients without CVD (p Conclusion A four week daily intake of sibutramine and life style changes was associated with significant reductions in mean uric acid levels. Changes in renal glucose load in diabetes seem to counteract a potential uricosuric effect of sibutramine. Trial Registration The trial is registered at ClinicalTrial.gov number: NCT00234832.

  5. Design and realization of the AMANDA software trigger for the TWA data readout system; Entwurf und Realisierung des AMANDA-Softwaretriggers fuer das TWR-Datenauslese-System

    Energy Technology Data Exchange (ETDEWEB)

    Messarius, Timo

    2006-07-15

    The thesis begins with a short introduction in the theory of astroparticle physics. Especially the processes, which lead to signal respectively background events in neutrino detectors, are discussed. Thereafter follows the descripotion of the basing detection principle and the detectors AMANDA and IceCube. The following chapter considers the two data-acquisition systems of the AMANDA detector and explains the motivation for the construction of a new data-acquisition system. The newly designed trigger system is then extensively treated. First a completely on software basing system is discussed, and then the implemented version is considered more detailedly. A procedure to detect and to mark events from atmospheric muons directly on trigger level is presented.

  6. Lead, hemoglobin, zinc protoporphyrin and ferritin concentrations in children Concentrações de chumbo, hemoglobina, zinco protoporfirina e ferritina em crianças

    Directory of Open Access Journals (Sweden)

    Patrícia H C Rondó

    2006-02-01

    Full Text Available OBJECTIVE: To assess the relationship of blood lead and hemoglobin, zinc protoporphyrin, and ferritin concentrations in children. METHODS: A cross-sectional study was carried out in 136 anemic and non-anemic children from two rural villages near a lead smelter in Adrianópolis, Southern Brazil, from July to September 2001. Hemoglobin electrophoresis was performed to exclude children with hemoglobin variants and thalassemia syndromes associated with anemia. Lead was determined by atomic absorption spectrophotometry; hemoglobin by automated cell counting; zinc protoporphyrin by hematofluorometry; ferritin by chemiluminescence. Student's t-test, Mann-Whitney test, and the c² test were used to assess the significance of the differences between the variables investigated in anemic and non-anemic children. Stepwise multivariate linear regression analysis was performed using two models for anemic and non-anemic children respectively. RESULTS: Lead was negatively associated to hemoglobin (pOBJETIVO: Avaliar a relação entre as concentrações sangüíneas de chumbo, hemoglobina, zinco protoporfirina e ferritina em crianças. MÉTODOS: Estudo transversal realizado com 136 crianças anêmicas e não anêmicas residentes em duas vilas da região rural de Adrianópolis, Estado do Paraná, próximas a uma usina de beneficiamento de chumbo, de julho a setembro de 2001. A eletroforese de hemoglobina foi realizada para excluir as crianças com anemia associada a hemoglobinas variantes e síndromes talassêmicas. O chumbo foi determinado por meio de espectrofotometria de absorção atômica; a hemoglobina por contador celular automático; a zinco protoporfirina por hematofluorometria, e a ferritina por quimioluminescência. Os testes t de student, Mann-Whitney e chi2 foram utilizados para verificar a significância das diferenças entre as variáveis. Foi realizada uma análise de regressão linear multivariada stepwise, utilizando dois modelos, para crian

  7. Investigation on Concentrations of Blood Lead, Urinary Lead and Serum Sex Hormone among Lead-exposed Male Workers%某蓄电池厂铅作业男工血铅、尿铅及血清中性激素水平的调查

    Institute of Scientific and Technical Information of China (English)

    虞敏; 周金鹏; 李倩兰

    2011-01-01

    [Objective]To evaluate the levels of blood lead and urinary lead and among lead-exposed male workers and the influencing factors, and study the variation of serum sex hormone and its related mechanism.[Methods]A total of 120 male workers that engaged in lead-exposed operation were selected from a lead storage battery manufacture plant as the exposed group in January 2011,which was furthermore partitioned into high, medium and low- dose exposed-groups.Another 40 male workers without lead exposure from the same plant were selected as the control group.Urine samples were collected for the measurement of urinary lead, and blood samples for measurements of blood lead, serum testosterone, FSH and LH.[Results]The average lead concentration in the workplace air was 0.29 mg/m3 , and 90% samples' concentration were higher than the national occupational health standard.Blood and urinary lead level and abnormity rate of 3 exposed-groups were all increased significantly compared with the control group, and differences of blood lead level and abnormity rate between the 3 exposed-groups were also significant( all P <0.01 ).With the growth of the length of service, blood and urinary lead level and abnormity rate of 3 exposed-groups represented a increasing tendency.Serum testosterone concentration of the medium and high dose exposed-groups were decreased significantly compared to the control group and the low dose exposed-group, to which the results of serum FSH concentrations were contrary( all P <0.01 ).[Conclusion]Under the conditions of this study, the growth of service length and high concentration of lead in the work place are both major risk factors for the increasing of blood and urinary lead.Lead-exposure can influence the sex hormone secreting function of hypothalamns-hypophysis-testicle axis, which will make interference effect on interual secretion of male workers' reproductive system.%目的 评价铅作业男性工人的血铅、尿铅水平及其影响因素,

  8. Ecotoxicology: Lead

    Science.gov (United States)

    Scheuhammer, A.M.; Beyer, W.N.; Schmitt, C.J.; Jorgensen, Sven Erik; Fath, Brian D.

    2008-01-01

    Lead (Pb) is a naturally occurring metallic element; trace concentrations are found in all environmental media and in all living things. However, certain human activities, especially base metal mining and smelting; combustion of leaded gasoline; the use of Pb in hunting, target shooting, and recreational angling; the use of Pb-based paints; and the uncontrolled disposal of Pb-containing products such as old vehicle batteries and electronic devices have resulted in increased environmental levels of Pb, and have created risks for Pb exposure and toxicity in invertebrates, fish, and wildlife in some ecosystems.

  9. Inter-Species Differences Between Lead Concentration in the Feathers of Pycnonotus leucogenys and Streptopelia seneglenses from Different Cities of Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Mansour I. Almansour

    2007-01-01

    Full Text Available This investigation was conducted to determine lead accumulation in feathers of wild white-cheeked bulbul (Pycnonotus leucogenys and wild palm dove (Streptopelia seneglenses in order to find which is more suitable to monitor the lead environmental pollution. Feather samples of 270 of Pycnonotus leucogenys and 309 of Streptopelia seneglenses were collected from three different cities of Saudi Arabia (Jeddah, Riyadh and Al-Kharj and were analyzed for lead by atomic absorption spectroscopy. The results obtained in this study revealed that the feathers of Streptopelia seneglenses have more capacity to retain lead than Pycnonotus leucogenys in Jeddah and Riyadh (pStreptopelia seneglenses is more suitable as a biological monitor for environmental lead exposure than Pycnonotus leucogenys.

  10. Effects of chronic exposure to sublethal concentrations of lead acetate on heme synthesis and immune function in red-tailed hawks.

    Science.gov (United States)

    Redig, P T; Lawler, E M; Schwartz, S; Dunnette, J L; Stephenson, B; Duke, G E

    1991-07-01

    Red-tailed hawks were exposed to sublethal levels of lead acetate for periods of 3 or 11 weeks. Alterations in the heme biosynthetic pathway were demonstrated after the first week of exposure to 0.82 mg lead per kilogram body weight per day. Activity of erythrocyte porphobilinogen synthase (aminolevulinic acid dehydratase) was depressed significantly and did not return to normal levels until 5 weeks after the termination of lead treatments. A rapid and relatively brief increase in erythrocyte free protoporphyrin and a slower but more prolonged increase in its zinc complex were also demonstrated with exposure to this dose of lead for 3 weeks. Less substantial decreases in hematocrit and hemoglobin levels occurred but only in the longer experiment with exposure to higher lead levels. Short term, low level lead exposure did not effect immune function significantly in the hawks, as measured by antibody titers to foreign red blood cells or by the mitogenic stimulation of T-lymphocytes. Increased lead exposure produced a significant decrease in the mitogenic response but had no effect on antibody titers.

  11. An investigation of selenium, mercury, and lead concentrations in sediment and biota from Maxwell National Wildlife Refuge, Colfax County, New Mexico

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The U.S. Fish and Wildlife Service (Service) conducted this investigation during the summer of 1991 to: (1) determine the nature and extent of selenium, lead, and...

  12. Role of Additives in Minimizing Zinc Electrode Shape Change: The Effect of Lead on the Kinetics of Zn(II) Reduction in Concentrated Alkaline Media.

    Science.gov (United States)

    1985-07-01

    adherent, and showed excellent physical stability. U -12- 4. RESULTS AND DISCUSSION 4.1 CYCLIC VOLTAMETRY AT A SILVER DISK ELECTRODE Silver screens are... cyclic voltammetry, :*.,. chronopotentiometry and chronocoulometry. A significant reduction in the rate of zinc deposition in the pre- sence of lead was... cyclic voltammetry, chronopotentiometry and chronocoulometry. A significant reduction in the rate of zinc deposition in the pre- sence of lead was

  13. Associations between land cover/use categories and soil concentrations of arsenic, lead and barium, and population race/ethnicity and socioeconomic status

    Science.gov (United States)

    Davis, Harley T.; Aelion, C. Marjorie; Lawson, Andrew B.; Cai, Bo; McDermott, Suzanne

    2015-01-01

    The potential of using land cover/use categories as a proxy for soil metal concentrations was examined by measuring associations between percentages of Anderson land cover categories with soil concentrations of As, Pb, and Ba in ten sampling areas. Land cover category and metal associations with ethnicity and socioeconomic status at the United States Census 2000 block and block group levels also were examined. Arsenic and Pb were highest in urban locations; Ba was a function of geology. Consistent associations were observed between urban/built up land cover, and Pb and poverty. Land cover can be used as proxy for metal concentrations, although associations are metal-dependent. PMID:24914533

  14. Analysis of Blood Concentrations of Zinc, Germanium, and Lead and Relevant Environmental Factors in a Population Sample from Shandong Province, China

    Directory of Open Access Journals (Sweden)

    Long Li

    2017-02-01

    Full Text Available Trace elements, including zinc (Zn and germanium (Ge, are essential for health; deficiency or excess levels of trace elements results is harmful. As a result of industrial and agricultural production, Pb widely exists in people’s living environment. It is absorbed mainly through the respiratory and digestive tracts, producing systemic harm. Reference values for a normal, healthy population are necessary for health assessment, prevention and treatment of related diseases, and evaluation of occupational exposures. Reference ranges for the Chinese population have not been established. From March 2009 to February 2010; we collected data and blood samples (n = 1302 from residents aged 6–60 years living in Shandong Province, China. We measured blood concentrations of Zn, Ge, and Pb using inductively coupled plasma mass spectrometry to determine reference ranges. Results were stratified by factors likely to affect the concentrations of these trace elements: sex, use of cosmetics or hair dye, age, alcohol intake, smoking habits, and consumption of fried food. The overall geometric mean (GM concentrations (95% confidence interval were 3.14 (3.08–3.20 mg/L for Zn, 19.9 (19.3–20.6 μg/L for Ge, and 24.1 (23.2–25.1 μg/L for Pb. Blood Zn concentrations were higher in women than in men (p < 0.001, while the opposite was found for Pb (p < 0.001 and sex did not influence Ge (p = 0.095. Alcohol use was associated with higher blood concentrations of Zn (p = 0.002, Ge (p = 0.002, and Pb (p = 0.001. The GM concentration of Zn was highest in 20–30-year-olds (p < 0.001, while Pb concentrations were highest in 12–16-year-olds (p < 0.001. Use of hair dye was associated with lower blood concentrations of Ge (p < 0.05. GM blood concentrations of Pb differed significantly between those who consumed fried foods 1–2 times/month (18.7 μg/L, 1–2 times/week (20.9 μg/L, and every day (28.5 μg/L; p < 0.001. Blood Pb concentrations were higher in subjects

  15. Cadmium and lead concentrations in Skrjabinotaenia lobata (Cestoda: Catenotaeniidae) and in its host, Apodemus sylvaticus (Rodentia: Muridae) in the urban dumping site of Garraf (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Jordi [Laboratori de Parasitologia, Departament de Microbiologia i Parasitologia Sanitaries, Facultat de Farmacia, Universitat de Barcelona, Av. Joan XXIII, sn, 08028 Barcelona (Spain)]. E-mail: jtorres@ub.edu; Peig, Jordi [Departament de Biologia Animal (Vertebrats), Facultat de Biologia, Universitat de Barcelona, Av. Diagonal 645, 08028 Barcelona (Spain); Eira, Catarina [Laboratori de Parasitologia, Departament de Microbiologia i Parasitologia Sanitaries, Facultat de Farmacia, Universitat de Barcelona, Av. Joan XXIII, sn, 08028 Barcelona (Spain); Borras, Miquel [Unitat de Toxicologia Experimental i Ecotoxicologia. Parc Cientific de Barcelona, C/Josep Samitier 1-5, 08028 Barcelona (Spain)

    2006-09-15

    The present study evaluates the parasitological model constituted by the wood mouse (Apodemus sylvaticus) and its intestinal cestode (Skrjabinotaenia lobata) as a potential bioindicator of Cd and Pb in the urban dumping site of Garraf near the city of Barcelona (Spain) and in Begues (reference site). Tissues and respective S. lobata specimens of 38 wood mice captured in Garraf and Begues were analyzed for Cd and Pb by means of ICP-MS. Higher cadmium levels in S. lobata were found only in respect to the muscular levels of their hosts. Nevertheless, lead levels were 8.5-, 53.2- and 81.4-fold higher in S. lobata than kidney, liver and muscle levels of A. sylvaticus from Garraf, respectively. Thus, the proposed model seems to be a promising bioindicator to evaluate environmental lead exposure in terrestrial habitats. In addition, all available data on lead bioaccumulation by cestode parasites of terrestrial mammals are generally discussed. - The parasitological model S. lobata/A. sylvaticus presents suitable features to be used as a bioindicator of lead pollution in terrestrial habitats.

  16. Prenatal exposure to lead and cognitive deficit in 7- and 14-year-old children in the presence of concomitant exposure to similar molar concentration of methylmercury

    DEFF Research Database (Denmark)

    Yorifuji, Takashi; Debes, Frodi; Weihe, Pal

    2011-01-01

    observed. In particular, higher cord-blood lead was associated with a lower digit span forward score on the Wechsler Intelligence Scale for Children-Revised (WISC-R) [beta=-1.70, 95% confidence interval (CI): -3.12 to -0.28] at age 7 and a lower digit span backward score on the WISC-R (beta=-2.73, 95%CI...

  17. Extensive changes in innate immune gene expression in obese Göttingen minipigs do not lead to changes in concentrations of circulating cytokines and acute phase proteins

    DEFF Research Database (Denmark)

    Højbøge, Tina Rødgaard; Skovgaard, Kerstin; Moesgaard, S. G.;

    2014-01-01

    The usefulness of Göttingen minipigs as models for obesity and obesity-related pathologies is well established. The low-grade inflammation associated with obesity involves a range of innate immune factors; however, to our knowledge, the impact of obesity on innate immune factor expression has...... between adipose tissues and a decreased tissue-specific expression of cytokines and chemokines. In contrast to obese humans, no changes in serum concentrations of haptoglobin, C-reactive protein, serum amyloid A, tumor necrosis factor-α and interleukin 6 were found in obese Göttingen minipigs....... not been studied in Göttingen minipigs. Therefore, we studied the expression of innate immune genes in liver and adipose tissues as well as serum concentrations of cytokines and acute phase proteins in obese vs. lean Göttingen minipigs. In the liver, of 35 investigated genes, the expression of nine...

  18. Elevation of serum insulin concentration during euglycemic hyperinsulinemic clamp studies leads to similar activation of insulin receptor kinase in skeletal muscle of subjects with and without NIDDM

    DEFF Research Database (Denmark)

    Klein, H H; Vestergaard, H; Kotzke, G;

    1995-01-01

    The role of skeletal muscle insulin receptor kinase in the pathogenesis of non-insulin-dependent diabetes mellitus (NIDDM) was investigated. Muscle biopsies from 13 patients with NIDDM and 10 control subjects at fasting serum insulin concentrations and approximately 1,000 pmol/l steady-state serum...... insulin during euglycemic hyperinsulinemic clamps were immediately frozen. The biopsies were then solubilized, and the receptors were immobilized to anti-insulin receptor antibody-coated microwells. Receptor kinase and binding activities were consecutively measured in these wells. The increase in serum...... insulin concentration (73 +/- 14 to 1,004 +/- 83 and 45 +/- 7 to 1,07 +/- 77 pmol/l in the NIDDM and control groups, respectively) had similar effects on receptor kinase activity in both study groups (12 +/- 1 to 42 +/- 5 and 12 +/- 2 to 47 +/- 5 amol P.fmol binding activity-1. min-1 in the NIDDM...

  19. Directional growth of Ag nanorod from polymeric silver cyanide: A potential substrate for concentration dependent SERS signal enhancement leading to melamine detection

    Science.gov (United States)

    Roy, Anindita; Sahoo, Ramkrishna; Chowdhury, Joydeep; Bhattacharya, Tara Shankar; Agarwal, Ratnesh; Pal, Tarasankar

    2017-08-01

    Attention has been directed to prepare exclusive one-dimensional silver nanostructure from the linear inorganic polymer AgCN. Successive color change from yellow to orange, to red and finally to green reflects the evolution of high yielding Ag nanorods (NRs) from well-known -[Ag-CN]- chains of polymeric AgCN at room temperature. The parental 1D morphology of AgCN is retained within the as-synthesized Ag NRs. So we could successfully exploit the Ag NR for surface-enhanced Raman scattering (SERS) studies for sensing a popular milk adulterant melamine down to picomolar level. We observed interesting concentration dependent selective SERS band enhancement of melamine. The enhanced 1327 cm- 1 SERS signal intensity at lower concentration (10- 9 and 10- 12 M) of melamine speaks for the preferential participation of -C-N of melamine molecule with Ag surface. On the other hand, '-NH2' group together with ring 'N' participation of melamine molecule onto Ag surface suggested an adsorptive stance at higher (10- 3-10- 7 M) concentration range. Thus the binding modes of the molecule at the Ag surface justify its fluxional behavior.

  20. Trends and variability in blood lead concentrations among US adults aged 20-64 years and senior citizens aged ≥65 years.

    Science.gov (United States)

    Jain, Ram B

    2016-07-01

    Using data from National Health and Nutrition Examination Survey for the period 2003-2012, the objective of this study was to evaluate trends in blood lead levels (BLL) among adults aged 20-64 years (adults) and seniors aged ≥65 years (seniors). In addition, the contribution of other factors like gender, race/ethnicity, smoking, and exposure to secondhand smoke at home in explaining variability in BLL was also evaluated by fitting regression models with log10 transformed values of BLL as dependent variables. BLL decreased over 2003-2012 (p seniors were found to have higher BLL than adults. Based on the magnitude of differences between the 5th and 95th percentiles, variability in the levels of blood lead was found to be substantially higher among seniors than among adults. Males had statistically significantly higher adjusted BLL than females (2.32 vs. 1.76 μg/dL for seniors, p seniors, p seniors, p obese had statistically significantly higher BLL than obese individuals (2.11 vs. 1.93 μg/dL for seniors, p seniors; β = 0.034, p = 0.034, p < 0.01 for adults).

  1. Environmental cadmium and lead concentrations in the Bahía Blanca Estuary (Argentina. Potential toxic effects of Cd and Pb on crab larvae

    Directory of Open Access Journals (Sweden)

    Laura Ferrer

    2000-12-01

    Full Text Available The Bahía Blanca Estuary includes a large tidal plain with an area close to 1150 km2. Mud is predominant in its sediments, where a significant population of the crab Chasmagnathus granulata lives during the whole year. Moreover, there are important urban and industrial discharges into this environment. Cd and Pb concentrations were determined in samples of water (for both dissolved and suspended particulate matter and surface sediments (total and 63 µm fractions. Organic matter was analysed in the sediments, while temperature, salinity, pH and dissolved oxygen were measured in the estuarine water. The metal concentrations determined in this study were: 1.47 ± 1.08 µg Cd g–1 and 14.68 ± 4.31 µg Pb g–1 in surface sediments; 2.21 ± 1.33 µg Cd g–1 and 25.70 ± 7.09 µg Pb g–1 in the –1 and below the analytical detection limit of Pb in suspended particulate matter. Furthermore, dissolved Cd and Pb were lower than the norms for marine and estuarine waters (2 µg dm–3 for Cd and 5 µg dm–3 for Pb, E.P.A.. Simultaneously, the effects of Cd and Pb were studied on recently hatched larvae of Ch. granulata, through 96-hour semi-static acute assays. Viability was the criterion assessed in the assays. LC50 (96 h for Cd was 46.43 µg dm–3 (36.92 - 56.34 µg dm–3, whilst that for Pb was 1.00 mg m–3 (0.79 - 1.23 mg dm–3, which demonstrates that Cd is more toxic towards larvae. Finally, both LC50 values determined for Cd and Pb were higher than the corresponding metal concentrations measured in the Bahía Blanca environment.

  2. Differential changes in serum uric acid concentrations in sibutramine promoted weight loss in diabetes: results from four weeks of the lead-in period of the SCOUT trial

    DEFF Research Database (Denmark)

    Andersson, Charlotte; Weeke, Peter; Brendorp, Bente;

    2009-01-01

    , but greater weight loss and diabetes were associated with smaller falls in blood uric acid levels; decreasing fasting and urinary glucose concentrations in diabetes were associated with increases in uric acid levels. CONCLUSION: A four week daily intake of sibutramine and life style changes was associated...... (mean +/- standard deviation) at screening were significantly higher among patients with CVD compared to patients without CVD (p ... with significant reductions in mean uric acid levels. Changes in renal glucose load in diabetes seem to counteract a potential uricosuric effect of sibutramine. TRIAL REGISTRATION: The trial is registered at ClinicalTrial.gov number: NCT00234832....

  3. 高铜铅精矿富氧底吹工业实践%Industrial Practice of Rich Oxygen Bottom Blowing Process of Smelting High Copper Content of Lead Concentrate

    Institute of Scientific and Technical Information of China (English)

    陈学兴; 欧阳坤

    2014-01-01

    A lead factory had smelted a batch of high copper content of lead concentrate , through two months of industrial practice , high copper content of lead concentrate had certain influence to the produc-tion of bottom blowing furnace and fuming furnace . The industrial test results showed that copper can be enriched in the crude lead and matte , the copper content of crude lead can reach more than 10 percent , the copper content of matte can reach more than 40 percent , the copper content of slag can be controlled under 0 .65 percent , and the recovery rate of copper can reach more than 90 percent .%某铅厂处理了一批高铜铅精矿,通过2个月的工业生产,入炉原料含铜高对底吹炉、烟化炉生产有一定影响,整个工业试验结果表明,铜可以在粗铅及锍中富集,粗铅含铜可达10%以上,锍含铜可达40%以上,弃渣含铜可控制在0.65%以下,铜的回收率可达90%。

  4. Pre-transitional evolution of central peaks and transverse acoustic phonon branch in single crystal lead zirconate titanate with Ti concentration 0.7%

    Science.gov (United States)

    Andronikova, D. A.; Bronwald, I. A.; Burkovsky, R. G.; Leontiev, I. N.; Leontiev, N. G.; Bosak, A. A.; Filimonov, A. V.; Vakhrushev, S. B.

    2016-11-01

    Inelastic X-ray scattering measurements have been done to study the lattice dynamics in lead zirconate titanate solid solution with 0.7% of PbTiO3. The temperature evolution of central peak and low-energy transverse phonon branches has been traced. Temperature dependent in-plane transverse polarized acoustic phonon branch in direction has been revealed. The central peaks of two types have been found. The central peak at small wave vectors can be attributed to the relaxational-type soft ferroelectric mode, while the latter at Q = (1.5 -0.5 0) could be linked to the formation of M-superstructure in the intermediate ferroelectric phase.

  5. BIOMONITORING OF AMBIENT CONCENTRATIONS OF CADMIUM,COPPER, LEAD AND ZINC IN THE COASTAL WETLAND WATER BY USING GILLS OF THE GREEN- LIPPED MUSSEL PERNA VIRIDIS

    Institute of Scientific and Technical Information of China (English)

    Chee Kong Yap; Ahmad Ismail; Abdul Rahim Ismail; Soon Guan Tan

    2006-01-01

    The distribution and concentrations of Cd, Cu, Pb and Zn were determined in the gills and remaining soft tissues of Perna viridis collected from 12 geographical sites ( 10 from the west and 2 from the east coastal waters) of Peninsular Malaysia. All samples showed that the levels of Cd, Pb and Zn were generally higher in the gill than those in the remaining soft tissues. These results could be due to the fact that gills are the first organ of metal accumulation and larger surface area with mucus sheets in the organ. Since the mussel gill is a better accumulator of Cd, Pb and Zn of ambient seawater than remaining soft tissue, it is a potential indicator of ambient levels of dissolved metals in the ambient seawater. However, further validations based on laboratory conditions are needed.

  6. Statistical comparison between consecutive winter and summer concentrations in zinc and lead from sediments in a tropical urban estuary in Mauritius.

    Science.gov (United States)

    Ramessur, Roshan Teewary; Boodhoo, Kishore; Balgobin, Janita; Aurellio, Andre

    2010-09-01

    Zn and Pb were quantified using atomic absorption spectrometry from urban and rural estuarine sediments collected along the western coast of Mauritius over three consecutive dry winter and wet summer periods from August 2004 to February 2009. The mean concentrations of Zn (204.0 +/- 92.3 mg kg(-1)) and Pb (44.5 +/- 16.4 mg kg(-1)) in sediments at Sable Noir, an urban estuary, can be considered below those from contaminated estuarine sediments in industrialised countries. Pb significantly decreased from two consecutive winters 2004/2005 to summer 2005/2006 at Sable Noir at 5% significance level due to flash floods in summer and dilution with cleaner background sediments. Pb was however significantly higher at Sable Noir in winter 2004 compared to winter 2005 and significantly increased from summer 2005 to summer 2006 due to a minor diesel spill in the estuary. Both Pb and Zn were significantly higher at Sable Noir in winter 2004 compared to Flic en Flac in winter 2008. Pb and Zn were also significantly higher at Sable Noir in summer 2005 compared to Flic en Flac in summer 2009. The concentrations of Zn and Pb were also significantly positively correlated in the estuarine sediments. The potential common sources of Pb and Zn in the urban estuarine sediments at Sable Noir were considered to arise from road runoff and zinc galvanised road furniture causing significant quantities to be trapped. There is at present a need for long-term studies in the cycling of Pb and Zn in estuarine sediments to integrate coastal zone management strategies.

  7. Subtoxic Concentrations of Hepatotoxic Drugs Lead to Kupffer Cell Activation in a Human In Vitro Liver Model: An Approach to Study DILI

    Directory of Open Access Journals (Sweden)

    Victoria Kegel

    2015-01-01

    Full Text Available Drug induced liver injury (DILI is an idiosyncratic adverse drug reaction leading to severe liver damage. Kupffer cells (KC sense hepatic tissue stress/damage and therefore could be a tool for the estimation of consequent effects associated with DILI. Aim of the present study was to establish a human in vitro liver model for the investigation of immune-mediated signaling in the pathogenesis of DILI. Hepatocytes and KC were isolated from human liver specimens. The isolated KC yield was 1.2±0.9×106 cells/g liver tissue with a purity of >80%. KC activation was investigated by the measurement of reactive oxygen intermediates (ROI, DCF assay and cell activity (XTT assay. The initial KC activation levels showed broad donor variability. Additional activation of KC using supernatants of hepatocytes treated with hepatotoxic drugs increased KC activity and led to donor-dependent changes in the formation of ROI compared to KC incubated with supernatants from untreated hepatocytes. Additionally, a compound- and donor-dependent increase in proinflammatory cytokines or in anti-inflammatory cytokines was detected. In conclusion, KC related immune signaling in hepatotoxicity was successfully determined in a newly established in vitro liver model. KC were able to detect hepatocyte stress/damage and to transmit a donor- and compound-dependent immune response via cytokine production.

  8. Subtoxic Concentrations of Hepatotoxic Drugs Lead to Kupffer Cell Activation in a Human In Vitro Liver Model: An Approach to Study DILI.

    Science.gov (United States)

    Kegel, Victoria; Pfeiffer, Elisa; Burkhardt, Britta; Liu, Jia L; Zeilinger, Katrin; Nüssler, Andreas K; Seehofer, Daniel; Damm, Georg

    2015-01-01

    Drug induced liver injury (DILI) is an idiosyncratic adverse drug reaction leading to severe liver damage. Kupffer cells (KC) sense hepatic tissue stress/damage and therefore could be a tool for the estimation of consequent effects associated with DILI. Aim of the present study was to establish a human in vitro liver model for the investigation of immune-mediated signaling in the pathogenesis of DILI. Hepatocytes and KC were isolated from human liver specimens. The isolated KC yield was 1.2 ± 0.9 × 10(6) cells/g liver tissue with a purity of >80%. KC activation was investigated by the measurement of reactive oxygen intermediates (ROI, DCF assay) and cell activity (XTT assay). The initial KC activation levels showed broad donor variability. Additional activation of KC using supernatants of hepatocytes treated with hepatotoxic drugs increased KC activity and led to donor-dependent changes in the formation of ROI compared to KC incubated with supernatants from untreated hepatocytes. Additionally, a compound- and donor-dependent increase in proinflammatory cytokines or in anti-inflammatory cytokines was detected. In conclusion, KC related immune signaling in hepatotoxicity was successfully determined in a newly established in vitro liver model. KC were able to detect hepatocyte stress/damage and to transmit a donor- and compound-dependent immune response via cytokine production.

  9. The Influence of Lead Concentration on Photocatalytic Reduction of Pb(II Ions Assisted by Cu-TiO2 Nanotubes

    Directory of Open Access Journals (Sweden)

    Srimala Sreekantan

    2014-01-01

    Full Text Available Cu2+ ions were successfully loaded into TiO2 nanotubes using wet impregnation technique in 0.6 M Cu(NO32·3H2O solution. The effect of reaction temperatures on the nanotube’s morphology, crystal structure, and their photocatalytic reduction of Pb(II ions were investigated. The high reaction temperature could improve the crystallinity of anatase phase. However, irregular and corrugated nanotubular surface covered with Cu precipitates was observed. In the present study, incorporation of an optimum content of Cu element (1.3 at% into TiO2 nanotubes at room temperature has an important function in enhancing the photocatalytic reduction of Pb(II ions in alkaline condition (pH 11 due to the higher synergistic effects of photocatalytic reaction under UV illumination. The optimum concentration of Pb(II ions for effective Pb(II ions removal performance was found in between 20 and 60 ppm.

  10. Parental exposure to environmental concentrations of diuron leads to aneuploidy in embryos of the Pacific oyster, as evidenced by fluorescent in situ hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Barranger, Audrey, E-mail: audrey.barranger@ifremer.fr [Ifremer, SG2M, Laboratory of Genetics and Pathology of Marine Molluscs, Avenue de Mus du Loup, 17390 La Tremblade (France); Ifremer, Department of Biogeochemistry and Ecotoxicology, Laboratory of Ecotoxicology, Rue de l’Ile d’Yeu, BP 21105, 44311 Nantes Cedex 03 (France); Benabdelmouna, Abdellah, E-mail: abdellah.benabdelmouna@ifremer.fr [Ifremer, SG2M, Laboratory of Genetics and Pathology of Marine Molluscs, Avenue de Mus du Loup, 17390 La Tremblade (France); Dégremont, Lionel [Ifremer, SG2M, Laboratory of Genetics and Pathology of Marine Molluscs, Avenue de Mus du Loup, 17390 La Tremblade (France); Burgeot, Thierry; Akcha, Farida [Ifremer, Department of Biogeochemistry and Ecotoxicology, Laboratory of Ecotoxicology, Rue de l’Ile d’Yeu, BP 21105, 44311 Nantes Cedex 03 (France)

    2015-02-15

    Highlights: • FISH was realized on oyster embryos from diuron-exposed genitors. • rDNA genes were used as probes on the interphase nuclei of embryo preparations. • Higher aneuploidy level was observed in embryos from diuron-exposed genitors. • Hypo- and hyperdiploid (triploid) nuclei were detected. - Abstract: Changes in normal chromosome numbers (i.e. aneuploidy) due to abnormal chromosome segregation may arise either spontaneously or as a result of chemical/radiation exposure, particularly during cell division. Coastal ecosystems are continuously subjected to various contaminants originating from urban, industrial and agricultural activities. Genotoxicity is common to several families of major environmental pollutants, including pesticides, which therefore represent a potential important environmental hazard for marine organisms. A previous study demonstrated the vertical transmission of DNA damage by subjecting oyster genitors to short-term exposure to the herbicide diuron at environmental concentrations during gametogenesis. In this paper, Fluorescent in situ hybridization (FISH) was used to further characterize diuron-induced DNA damage at the chromosomal level. rDNA genes (5S and 18-5.8-28S), previously mapped onto Crassostrea gigas chromosomes 4, 5 and 10, were used as probes on the interphase nuclei of embryo preparations. Our results conclusively show higher aneuploidy (hypo- or hyperdiploidy) level in embryos from diuron-exposed genitors, with damage to the three studied chromosomal regions. This study suggests that sexually developing oysters are vulnerable to diuron exposure, incurring a negative impact on reproductive success and oyster recruitment.

  11. Effects of cadmium and lead concentrations and arbuscular mycorrhiza on growth, flowering and heavy metal accumulation in scarlet sage (Salvia splendens sello 'torreador'

    Directory of Open Access Journals (Sweden)

    Joanna Nowak

    2012-12-01

    Full Text Available The objective of this research was to examine the influence of Cd (0, 10, 20, 40 mg Cd·dm-3 and Pb (0, 10, 100, 200 mg Pb·dm-3 in growing substrate and mycorrhizal colonization of root system on growth, flowering, Cd and Pb accumulation in scarlet sage shoots. Both Cd and Pb had a negative effect on mycorrhizal colonization of scarlet sage roots. The effect of Cd and Pb on the growth of scarlet sage was negligible. Cd at 40 mg·dm-3 lowered the number of inflorescences and caused slight chlorosis of the lowermost leaves. Pb at 200 mg·dm-3 caused drying of the lowermost leaves. Both heavy metals accelerated flowering of non-mycorrhizal plants, independently of the concentration in growing media. Cd and Pb contents in scarlet sage shoots increased with the increasing content of these heavy metals in growing substrate in both non-mycorrhizal and mycorrhizal plants. Mycorrhization decreased the growth of scarlet sage and increased the accumulation of Cd and Pb in shoots of plants grown in media strongly polluted with heavy metals.

  12. Time weighted average concentration monitoring based on thin film solid phase microextraction.

    Science.gov (United States)

    Ahmadi, Fardin; Sparham, Chris; Boyaci, Ezel; Pawliszyn, Janusz

    2017-03-02

    Time weighted average (TWA) passive sampling with thin film solid phase microextraction (TF-SPME) and liquid chromatography tandem mass spectrometry (LC-MS/MS) was used for collection, identification, and quantification of benzophenone-3, benzophenone-4, 2-phenylbenzimidazole-5-sulphonic acid, octocrylene, and triclosan in the aquatic environment. Two types of TF-SPME passive samplers, including a retracted thin film device using a hydrophilic lipophilic balance (HLB) coating, and an open bed configuration with an octadecyl silica-based (C18) coating, were evaluated in an aqueous standard generation (ASG) system. Laboratory calibration results indicated that the thin film retracted device using HLB coating is suitable to determine TWA concentrations of polar analytes in water, with an uptake that was linear up to 70 days. In open bed form, a one-calibrant kinetic calibration technique was accomplished by loading benzophenone3-d5 as calibrant on the C18 coating to quantify all non-polar compounds. The experimental results showed that the one-calibrant kinetic calibration technique can be used for determination of classes of compounds in cases where deuterated counterparts are either not available or expensive. The developed passive samplers were deployed in wastewater-dominated reaches of the Grand River (Kitchener, ON) to verify their feasibility for determination of TWA concentrations in on-site applications. Field trials results indicated that these devices are suitable for long-term and short-term monitoring of compounds varying in polarity, such as UV blockers and biocide compounds in water, and the data were in good agreement with literature data.

  13. EMA: a developmentally regulated cell-surface glycoprotein of CNS neurons that is concentrated at the leading edge of growth cones.

    Science.gov (United States)

    Baumrind, N L; Parkinson, D; Wayne, D B; Heuser, J E; Pearlman, A L

    1992-08-01

    To identify cell-surface molecules that mediate interactions between neurons and their environment during neural development, we used monoclonal antibody techniques to define a developmentally regulated antigen in the central nervous system of the mouse. The antibody we produced (2A1) immunolabels cells throughout the central nervous system; we analyzed its distribution in the developing cerebral cortex, where it is expressed on cells very soon after they complete mitosis and leave the periventricular proliferative zone. Expression continues into adult life. The antibody also labels the epithelium of the choroid plexus and the renal proximal tubules, but does not label neurons of the peripheral nervous system in the dorsal root ganglia. In dissociated cell culture of embryonic cerebral cortex, 2A1 labels the surface of neurons but not glia. Immunolabeling of neurons in tissue culture is particularly prominent on the edge of growth cones, including filopodia and the leading edge of lamellipodia, when observed with either immunofluorescence or freeze-etch immunoelectron microscopy. Immunopurification with 2A1 of a CHAPS-extracted membrane preparation from brains of neonatal mice produces a broad (32-36 kD) electrophoretic band and a less prominent 70 kD band that are sensitive to N-glycosidase but not endoglycosidase H. Thus the 2A1 antibody recognizes a developmentally regulated, neuronal cell surface glycoprotein (or glycoproteins) with complex N-linked oligosaccharide side chains. We have termed the glycoprotein antigen EMA because of its prominence on the edge membrane of growth cones. EMA is similar to the M6 antigen (Lagenaur et al: J. Neurobiol. 23:71-88, 1992) in apparent molecular weight, distribution in tissue sections, and immunoreactivity on Western blots, suggesting that the two antigens are similar or identical. Expression of EMA is a very early manifestation of neuronal differentiation; its distribution on growth cones suggests a role in mediating the

  14. Controllable biosynthesis of high-purity lead-sulfide (PbS) nanocrystals by regulating the concentration of polyethylene glycol in microbial system.

    Science.gov (United States)

    Yue, Lei; Wang, Jia; Zhang, Yongtao; Qi, Shiyue; Xin, Baoping

    2016-12-01

    We demonstrated a simple biological method to explore the controllable synthesize of high-purity PbS nanocrystals by regulating the concentration of polyethylene glycol in microbial system. The biogenic H2S produced via the reduction of sulfate precipitated Pb(2+) ions as sulfide extracellularly, and the optimal removal rate of Pb(2+) ions is up to 96.7 % in 2 weeks. The characterization results showed that PbS nanocuboids with a particle size 50 × 50 × 100 nm obtained from Case A with 4 mM polyethylene glycol as a dispersant, and can completely degrade methylene blue from solution within 20 h; PbS nanosheets with a thickness size ca. 10 nm attained from Case B with 12 mM polyethylene glycol, and it can degrade 61.6 % dye within 24 h; PbS nanoparticles with a uniform diameter of ca. 60 nm formed from Case C with 20 mM polyethylene glycol, only degrade 14.1 % dye within 24 h. It is interesting that the factor affecting their catalytic activities is not the specific surface area, but the number of [200] crystal plane. This work not only displayed a simple synthetic method to control the morphology of PbS nanocrystals in microbial system, but also provided an economic and environmentally friendly approach for resourceful treatment and efficient bioremediation of wastewater-containing heavy metal.

  15. Concentrations of strontium, barium, cadmium, copper, zinc, manganese, chromium, antimony, selenium, and lead in the liver and kidneys of dogs according to age, gender, and the occurrence of chronic kidney disease.

    Science.gov (United States)

    Passlack, Nadine; Mainzer, Barbara; Lahrssen-Wiederholt, Monika; Schafft, Helmut; Palavinskas, Richard; Breithaupt, Angele; Zentek, Jürgen

    2015-01-01

    This study was conducted to measure the concentrations of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se), and lead (Pb) in canine liver, renal cortex, and renal medulla, and the association of these concentrations with age, gender, and occurrence of chronic kidney disease (CKD). Tissues from 50 dogs were analyzed using inductively coupled plasma mass spectrometry. Cu, Zn, and Mn levels were highest in the liver followed by the renal cortex and renal medulla. The highest Sr, Cd, and Se concentrations were measured in the renal cortex while lower levels were found in the renal medulla and liver. Female dogs had higher tissue concentrations of Sr (liver and renal medulla), Cd (liver), Zn (liver and renal cortex), Cr (liver, renal cortex, and renal medulla), and Pb (liver) than male animals. Except for Mn and Sb, age-dependent variations were observed for all element concentrations in the canine tissues. Hepatic Cd and Cr concentrations were higher in dogs with CKD. In conclusion, the present results provide new knowledge about the storage of specific elements in canine liver and kidneys, and can be considered important reference data for diagnostic methods and further investigations.

  16. Lead Poisoning

    Science.gov (United States)

    Lead is a metal that occurs naturally in the earth's crust. Lead can be found in all parts of our ... from human activities such as mining and manufacturing. Lead used to be in paint; older houses may ...

  17. FIRST IMAGES OF DEBRIS DISKS AROUND TWA 7, TWA 25, HD 35650, AND HD 377

    Energy Technology Data Exchange (ETDEWEB)

    Choquet, Élodie; Perrin, Marshall D.; Chen, Christine H.; Soummer, Rémi; Pueyo, Laurent; Hagan, James B.; Gofas-Salas, Elena; Golimowski, David A.; Hines, Dean C.; Mazoyer, Johan; Debes, John; Stark, Christopher C.; N’Diaye, Mamadou [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Rajan, Abhijith [Arizona State University, Phoenix, AZ 85004 (United States); Schneider, Glenn [Steward Observatory, The University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Augereau, Jean-Charles [Univ. Grenoble Alpes, IPAG, F-38000 Grenoble (France); Wolff, Schuyler; Hsiao, Kevin, E-mail: choquet@stsci.edu [Johns Hopkins University, 3400 North Charles Street, Baltimore MD 21218 (United States)

    2016-01-20

    We present the first images of four debris disks observed in scattered light around the young (4–250 Myr old) M dwarfs TWA 7 and TWA 25, the K6 star HD 35650, and the G2 star HD 377. We obtained these images by reprocessing archival Hubble Space Telescope NICMOS coronagraph data with modern post-processing techniques as part of the Archival Legacy Investigation of Circumstellar Environments program. All four disks appear faint and compact compared with other debris disks resolved in scattered light. The disks around TWA 25, HD 35650, and HD 377 appear very inclined, while TWA 7's disk is viewed nearly face-on. The surface brightness of HD 35650's disk is strongly asymmetric. These new detections raise the number of disks resolved in scattered light around M and late-K stars from one (the AU Mic system) to four. This new sample of resolved disks enables comparative studies of heretofore scarce debris disks around low-mass stars relative to solar-type stars.

  18. Lead Toxicity

    Science.gov (United States)

    ... including some imported jewelry. What are the health effects of lead? • More commonly, lower levels of lead in children over time may lead to reduced IQ, slow learning, Attention Deficit Hyperactivity Disorder (ADHD), or behavioral issues. • Lead also affects other ...

  19. The association of peripubertal serum concentrations of organochlorine chemicals and blood lead with growth and pubertal development in a longitudinal cohort of boys: a review of published results from the Russian Children's Study.

    Science.gov (United States)

    Sergeyev, Oleg; Burns, Jane S; Williams, Paige L; Korrick, Susan A; Lee, Mary M; Revich, Boris; Hauser, Russ

    2017-02-23

    Organochlorine chemicals and lead are environmental exposures that have endocrine disrupting properties (EDCs) which interfere with many aspects of hormone action. Childhood and adolescence are windows of susceptibility for adverse health effects of EDCs. Our ongoing study, the Russian Children's Study (RCS), is one of the few longitudinal studies investigating the impact of EDCs on growth and puberty in boys. It is conducted in the historically contaminated city of Chapaevsk, in the Samara region. The study focuses on evaluating the associations of persistent organochlorine chemicals and lead with growth and pubertal timing. At enrollment in 2003-2005, we collected blood from 516 boys at ages 8-9 years to measure dioxins, furans, polychlorinated biphenyls (PCBs), chlorinated pesticides and lead. At enrollment and at annual visits through the ages of 18-19 years, a physician performed physical examinations that included pubertal staging and testicular volume measurements. We review the history of Chapaevsk as a research site and summarize published RCS data on the association of peripubertal serum concentrations of organochlorines and blood lead levels with growth, pubertal onset and sexual maturity. Overall, we found that persistent organochlorines and lead negatively affected growth during puberty. Our results also suggest that total toxic equivalents (TEQs), dioxin-like compounds, organochlorine pesticides and lead may delay, while nondioxin-like-PCBs may advance, the timing of male puberty. These findings promoted remediation programs in Chapaevsk, with improvement in health indicators, resulting in Chapaevsk being designated a member of the World Health Organization (WHO) network "Healthy Cities" in 2015.

  20. Research on Molybdenum Leaching from Low Grade Lead-Molybdenum Rough Concentrate%低品位铅钼粗精矿浸出氧化钼的研究

    Institute of Scientific and Technical Information of China (English)

    杨绍文; 曹耀华; 刘红召; 高照国

    2011-01-01

    The molybdenum in lead concentrate (Mo content of 4.39%) mainly existed in forms of PbMO4.The sodium sulfide leaching process was adopted for oxidation molybdenum extraction.The leaching rate of molybdenum was 85% under the conditions that particle size of ore was 83% —0.0074 mm, the dosage of sodium sulfide was two times as the theoretical value, the ratio of liquid (volume) to solid(mass) was 3 ∶ 1, the leaching temperature was 90~95 ℃ and the leaching lasted 1 h.So, Lead was remained in the leaching slag in the form of lead sulfide, and the separation of lead and molybdenum was achieved.%某低品位铅钼粗精矿中(含钼4.39%)钼主要以钼酸铅矿物形式存在,采用硫化钠浸出工艺提取氧化钼.在粒度-74 μm占83%、硫化钠用最为理论量的2.5倍、液固比3:1、浸出温度90~95℃、浸出时间1 h的条件下,钼浸出率85%,铅以硫化铅形式进入浸出渣,实现了钼酸铅矿中钼铅的分离.

  1. 某铅锌矿选矿废水的处理工艺探讨%Discussion on the Treatment Technology for the Wastewater of Concentrator in a Lead and Zinc Mine

    Institute of Scientific and Technical Information of China (English)

    张艳芬; 徐腮超

    2013-01-01

    针对某铅锌矿500 t/d选矿厂废水处理工艺,从废水水质水量、废水处理工艺方案、废水处理站工艺流程等方面进行探讨.%The quality and volume of waste water,waste water treatment process scheme,waste water treatment station and so on are discussed in this paper according to the waste water treatment technology in 500 t/d concentrator of a lead and zinc mine.

  2. Comparison of lead and tin concentrations in air at a solder manufacturer from the closed-face 37-mm cassette with and without a custom cellulose-acetate cassette insert.

    Science.gov (United States)

    Lee, Eun Gyung; Chisholm, William P; Burns, Dru A; Nelson, John H; Kashon, Michael L; Harper, Martin

    2014-01-01

    A polyvinyl chloride (PVC) cassette insert with PVC filter (ACCU-CAP) in a 37-mm closed-face cassette (CFC) was designed for gravimetric analysis. A customized version of the ACCU-CAP, also to be used in the CFC, was manufactured from an acid-digestible cellulose-acetate cassette insert joined to a mixed cellulose ester (MCE) filter for wet chemical analysis. The aim of this study was to compare metal particle concentrations as sampled by the customized insert (CI) in a CFC sampler with the traditional sampling method using only a MCE filter in the CFC. Thirty-nine personal and 13 area samples were taken using paired filter-based CFC and the CI in CFC samplers at a solder manufacturing plant. The CI was removed from its CFC, and digested and analyzed as a whole. The MCE filter from the typical CFC was removed for analysis and then the interior of the cassette was wiped with Ghost Wipe for a separate analysis. The MCE filter only, Ghost Wipe, and CI were separately dissolved in heated nitric acid for ICP-MS analysis. Overall, the geometric mean concentration of the filter-only (FO) samples was considerably lower than that of the CI samples, by 53% for lead and 32% for tin. However, if the FO analysis was added to the corresponding Ghost Wipe analysis, i.e., filter+interior wipe (FW), the geometric mean concentrations of the FW results were similar to those of the CI results (by 113% for lead and 98% for tin). For both lead and tin the comparison of (log-transformed) metal concentrations between the FW and CI results showed no statistically significant difference (p-value = 0.3009 for lead and 0.800 for tin), while the comparison between the FO and CI results shows statistically significant differences (all p-values < 0.05). In conclusion, incorporating the sampler internal non-filter deposits by wiping or use of an internal filter capsule gave higher results than analyzing only the filter. Close agreement between the two methods of including non-filter deposits is

  3. T-wave alternans in LQTS: repolarization-rate dynamics from digital 12-lead Holter data.

    Science.gov (United States)

    Brockmeier, K; Aslan, I; Hilbel, T; Eberle, T; Ulmer, H E; Lux, R L

    2001-01-01

    T-wave alternans (TWA) is a harbinger of ventricular vulnerability and an important prognostic indicator for torsade de pointes and likely sudden death in patients with LQTS. We analyzed the occurrence of TWA in 18 patients with LQTS (7 males, 11 females, ages ranging from 6 months to 32 years--median 8.4 years). Analysis was performed with software to investigate dynamics of cycle length mediated repolarization changes. Digital Holter ECG analysis revealed macroscopic, true TWA in 3 of 18 patients. TWA showed a variable morphological expression. One patient had continuous changes of T wave polarity, but not on a periodic beat-to-beat basis. Onsets of macroscopic TWA were preceded by long/short cycle length sequences and tachycardic rates above 130 to 140 bpm. Impact of ventricular premature beats on TWA onset was insignificant. Two of the identified patients with TWA had sudden cardiac death during follow-up (one refused PM therapy). At present, TWA cannot be detected automatically from Holter ECGs and therefore may be missed, despite the potential danger for the individuals. The observation that predominantly high beat rates and not beat rate changes, per se, triggered episodes of TWA renders difficult general therapeutic recommendations for the identified patients at risk.

  4. Predicting benzene vapor concentrations with a near field/far field model.

    Science.gov (United States)

    Nicas, Mark; Neuhaus, John

    2008-09-01

    Published data on benzene vapor concentrations in work simulation settings were used to examine the predictive ability of a near field/far field vapor dispersion model with an exponentially decreasing vapor emission rate. A given simulation involved two 15-min periods of applying a known volume of benzene-containing liquid to equipment on a worktable in a room with a measured air exchange rate. Replicate personal breathing zone (15-min time-weighted average, TWA) and room area (1-hr TWA) air samples were collected. In our modeling, the benzene vapor concentration in the near field zone (at the worktable) represented the personal breathing zone exposure level, and the benzene vapor concentration in the far field zone represented the room area concentration. Across 10 simulation combinations of two factors (the mass of benzene applied and the room air exchange rate), the mean of the personal breathing zone exposure levels ranged from 0.2 to 9.9 mg m(-3), and the mean of the room area concentrations ranged from 0.05 to 5.05 mg m(-3). Our model provided reasonably accurate estimates of the measured benzene vapor concentrations. Linear regression of the mean measured personal breathing zone exposure versus the predicted near field concentration yielded slope = 0.93 and r(2) = 0.94; the null hypothesis that the true slope equals one was not rejected (p-value = 0.39). Linear regression of the mean measured room area concentration versus the predicted far field concentration yielded slope = 0.90 and r(2) = 0.94; the null hypothesis that the true slope equals one was not rejected (p-value = 0.20). Other statistical tests showed no significant differences between measured and predicted values. In addition, most predicted concentrations fell within an approximate range of one-half to twofold the respective measured concentrations.

  5. Lead Poisoning

    Science.gov (United States)

    ... lead is of microscopic size, invisible to the naked eye. More often than not, children with elevated ... majority of the childhood lead poisoning cases we see today. Children and adults too can get seriously ...

  6. Relational Leading

    DEFF Research Database (Denmark)

    2015-01-01

    This first chapter presents the exploratory and curious approach to leading as relational processes – an approach that pervades the entire book. We explore leading from a perspective that emphasises the unpredictable challenges and triviality of everyday life, which we consider an interesting......, relevant and realistic way to examine leading. The chapter brings up a number of concepts and contexts as formulated by researchers within the field, and in this way seeks to construct a first understanding of relational leading....

  7. Transport and concentration controls for chloride, strontium, potassium and lead in Uvas Creek, a small cobble-bed stream in Santa Clara County, California, U.S.A. 2. Mathematical modeling

    Science.gov (United States)

    Jackman, A.P.; Walters, R.A.; Kennedy, V.C.

    1984-01-01

    Three models describing solute transport of conservative ion species and another describing transport of species which adsorb linearly and reversibly on bed sediments are developed and tested. The conservative models are based on three different conceptual models of the transient storage of solute in the bed. One model assumes the bed to be a well-mixed zone with flux of solute into the bed proportional to the difference between stream concentration and bed concentration. The second model assumes solute in the bed is transported by a vertical diffusion process described by Fick's law. The third model assumes that convection occurs in a selected portion of the bed while the mechanism of the first model functions everywhere. The model for adsorbing species assumes that the bed consists of particles of uniform size with the rate of uptake controlled by an intraparticle diffusion process. All models are tested using data collected before, during and after a 24-hr. pulse injection of chloride, strontium, potassium and lead ions into Uvas Creek near Morgan Hill, California, U.S.A. All three conservative models accurately predict chloride ion concentrations in the stream. The model employing the diffusion mechanism for bed transport predicts better than the others. The adsorption model predicts both strontium and potassium ion concentrations well during the injection of the pulse but somewhat overestimates the observed concentrations after the injection ceases. The overestimation may be due to the convection of solute deep into the bed where it is retained longer than the 3-week post-injection observation period. The model, when calibrated for strontium, predicts potassium equally well when the adsorption equilibrium constant for strontium is replaced by that for potassium. ?? 1984.

  8. 脐血铅浓度与新生儿端粒长度的相关性%A correlation study of umbilical cord blood lead concentrations and neonatal telomere length

    Institute of Scientific and Technical Information of China (English)

    赵艳芳; 曲宝明; 刘文东; 马海燕

    2014-01-01

    目的:研究脐血铅浓度与新生儿端粒长度的相关性。方法收集2010年7月~2013年4月青岛市市立医院产科孕期无急慢性疾病的足月顺产儿脐血78例,原子吸收光谱法测定脐血铅浓度,测得脐血铅浓度在11~89µg/L范围。将78例脐血分成A、B、C三组:A组脐血铅浓度<30µg/L,共28例,B组脐血铅浓度30~60µg/L,共38例,C组脐血铅浓度>60µg/L,共12例。采用全血提取基因组法提取脐血DNA,荧光定量PCR法测基因组DNA的端粒长度。各组间比较采用单因素方差分析,两两比较采用q检验,相关性采用Spearman相关性研究。结果A组端粒长度为:1.152±0.716,B组端粒长度为0.614±0.407,C组端粒长度为0.546±0.339,从A组到C组端粒长度逐渐缩短,且差异有统计学意义(F=4.895,P<0.05)。B组端粒长度低于A组,差异有统计学意义(P<0.05),C组端粒长度低于A组端粒长度,差异有统计学意义(P<0.01)。B、C两组之间的差异没有统计学意义(P>0.05)。三组端粒长度与脐血铅浓度呈负相关(r=-0.461,P<0.01)。结论脐血铅可导致新生儿端粒长度的缩短,且随脐血铅浓度的升高,新生儿端粒长度进行性缩短,端粒长度缩短影响细胞分裂,决定细胞寿命。%Objective To study the correlation of umbilical cord blood lead concentrations and neonatal telomere length. Methods We collected 78 cases of umbilical cord blood from term infants whose gestation was without acute or chronic disease from Qingdao Municipal Hospital between July of 2010 to April of 2013.We used atomic absorption spectrometry to determine the concentration of umbilical cord blood lead. The umbilical cord blood lead concentrations measured range was between 11 and 89 µg/L. The 78 cases of umbilical cord blood was divided into three groups:A,B,and C.Umbilical cord blood lead concentrations for group A was 60 µg/L (n=12).To

  9. Impact of the Deepwater Horizon Oil Spill on the Changes in the Seasonal Average Concentrations of Nickel, Vanadium, and Lead in Bottom Sediment Retrieved from the Outer Continental Shelf, Gulf of Mexico

    Science.gov (United States)

    Steffy, D. A.; Nichols, A.; Morgan, J.; Gibbs, R.

    2013-12-01

    Sediment samples were collected during the fall of 2010 and 2011from across the Gulf of Mexico outer continental shelf (OCS). A Tukey range test was used to compare samples between the relict sand deposits of the northern Gulf OCS to the relict carbonate sediments off of western Florida OCS. Tests indicate that nickel, vanadium, and lead are significantly higher (p < 0.05) in the seasonal average concentrations in the relict sand deposits closer to the Deepwater Horizon Well. These metals also significantly decreased (p < 0.05) from 2010 to 2011 in each region. These changes can be explained by the presence of a new source for these metals in the crude oil released from the Deepwater Horizon Oil Spill during the spring of 2010. Chromium and thallium did not vary seasonally or between the two areas of the OCS being investigated.

  10. Lead Test

    Science.gov (United States)

    ... months, and at 3, 4, 5, and 6 years of age. A blood lead level test should be done only if the risk ... recommended if the person is symptomatic at any level below 70 mcg/dL. Because lead will pass through the blood to an unborn child, pregnant ...

  11. Does Long-Term High Fat Diet Always Lead to Smaller Hippocampi Volumes, Metabolite Concentrations, and Worse Learning and Memory? A Magnetic Resonance and Behavioral Study in Wistar Rats.

    Directory of Open Access Journals (Sweden)

    Zuzanna Setkowicz

    Full Text Available Obesity is a worldwide epidemic with more than 600 million affected individuals. Human studies have demonstrated some alterations in brains of otherwise healthy obese individuals and elevated risk of neurodegenerative disease of old age; these studies have also pointed to slightly diminished memory and executive functions among healthy obese individuals. Similar findings were obtained in animal models of obesity induced by high fat diet. On the other hand, low carbohydrate high fat diets are currently promoted for losing weight (e.g., Atkin's style diets. However, the long-term effects of such diets are not known. Additionally, high fat diets leading to (mild ketonemia were shown to improve brain function in elderly humans and in some animal models.To evaluate the hypothesis that long-term use of a high fat diet was associated with decreases in spatial memory, smaller hippocampi and hippocampi metabolite concentrations in Wistar rats.Twenty five male Wistar rats were put on high fat diet (HFD; 60% calories from fat, 30% from carbohydrates on their 55th day of life, while 25 control male rats (CONs remained on chow. Adequate levels of essential nutrients were provided. Both groups underwent memory tests in 8-arm radial maze at 3rd, 6th, 9th, and 12th month. 1H magnetic resonance spectroscopy was employed to measure concentrations of tNAA (marker of neuronal integrity at one month and one year, whereas MRI was used to evaluate hippocampal volumes.Obese rats (OBRs consumed similar amount of calories as CONs, but less proteins. However, their protein intake was within recommended amounts. Throughout the experiment OBRs had statistically higher concentrations of blood ketone bodies than CONs, but still within normal values. At post-mortem assessment, OBRs had 38% larger fat deposits than CONs (p<0.05, as evaluated by volume of epididymis fat, an acknowledged marker of fat deposits in rats. Contrary to our expectations, OBRs had better scores of

  12. 氧压酸浸低品位富银硫化矿富集提取银和锌%Silver and Zinc Recoveries by Acid Pressure Oxidative Leaching of Silver-bearing Lead-Zinc-Iron Sulfide Concentrate

    Institute of Scientific and Technical Information of China (English)

    梁铎强; 王吉坤; 汪云华

    2008-01-01

    The beneficiation of silver-bearing lead-zinc-iron sulfide concentrate from Yunnan Lancang Lead Ore Co.,Ltd is very difficult because of existence of great deal of pyrite and marcasite with content up to 70%,and the a-certain-extent oxidation of galena to yellow lead.In the present work,acid pressure oxidative leaching of such complex sulfide was investigated at the temperature ranging 90~170℃ to shed new light on the deportment of silver from the source concentrates to the residue with subsequent recovery by cyanidation.Lab-scale leaching experiments were conducted in a 2L autoclave to investigate the influences of temperature,acidity,sodium iodide usage,oxygen partial pressure,oxygen flow rate on the recoveries of silver and zinc.The results obtained show that the recovery of silver depends on whether the leached silver is incorporated into jarosite or convened into silver iodide by reaction with sodium iodide.Under optimum conditions,recoveries of silver and zinc can reach 71.5% and 41.29%,respectively.%由于含有大量的黄铁矿和白铁矿(它们约占原矿的70%,质量分数),以及闪铅矿一定程度上的氧化,云南澜沧铅矿股份有限公司所产的富银硫化矿难以富集.本文通过对该矿在90-170℃下氧压酸浸,以期连同后面的氰化能提取精矿中的银.通过进行2L高压釜的小型试验,考察了温度、酸度、碘化钠用量、氧分压、氧气流速对银和锌回收率的影响.结果表明,银的回收率取决于银是否进入黄钾铁矾渣,或者与碘化钠反应生成碘化银沉淀.在优化的条件下,银和锌的回收率分别达到71.5%和41.29%.

  13. 原子吸收光谱法连续测定金精矿中的银铜铅锌%Continuous determination of silver,copper,lead and zinc in gold concentrates by atomic absorption spectrometry

    Institute of Scientific and Technical Information of China (English)

    孔令强; 李伟彦; 邵国强

    2016-01-01

    Separate determination of silver,copper,lead and zinc in gold concentrates in daily testing wastes time and labor. So AAS was used to continuously determine silver,copper,lead and zinc in single-time sample dissolution. Gold concentrates were dissolved by mixed HCl-HNO3 -HF-HClO4 ,calibrated by HCl(1+9) solution and deter-mined by AAS. The method achieved a recovery rate of 96. 9 % -107. 7 % with the addition of standard substance, the RSD(n=7) was 1. 17 % -7. 07 % and the detection limits were 0. 001 5 μg/mL for Cu,0. 029 9 μg/mL for Pb,0. 011 2 μg/mL for Zn,and 0. 001 9 μg/mL for Ag. The method for silver,copper,lead and zinc determination was consistent with national standard method.%针对金精矿日常化验中银、铜、铅、锌需分别溶样测定,浪费人力、时间,采用火焰原子吸收法一次溶样连续测定样品中的银、铜、铅、锌。金精矿采用盐酸-硝酸-氢氟酸-高氯酸混酸完全消解,盐酸(1+9)溶液定容,原子吸收光谱法进行测定。该方法加入标准物质回收率为96.9%~107.7%,相对标准偏差 RSD(n =7)为1.17%~7.07%,检出限分别为 Cu 0.0015μg/mL、Pb 0.0299μg/mL、Zn 0.0112μg/mL、Ag 0.0019μg/mL。该方法对金精矿中银、铜、铅、锌的测定结果与国家标准方法测定值相符。

  14. Lead Poisoning

    Science.gov (United States)

    ... Topics Environment & Health Healthy Living Pollution Reduce, Reuse, Recycle Science – How It Works The Natural World Games ... OTHERS: Lead has recently been found in some plastic mini-blinds and vertical blinds which were made ...

  15. Leading men

    DEFF Research Database (Denmark)

    Bekker-Nielsen, Tønnes

    2016-01-01

    Through a systematic comparison of c. 50 careers leading to the koinarchate or high priesthood of Asia, Bithynia, Galatia, Lycia, Macedonia and coastal Pontus, as described in funeral or honorary inscriptions of individual koinarchs, it is possible to identify common denominators but also...

  16. Lead grids

    CERN Multimedia

    1974-01-01

    One of the 150 lead grids used in the multiwire proportional chamber g-ray detector. The 0.75 mm diameter holes are spaced 1 mm centre to centre. The grids were made by chemical cutting techniques in the Godet Workshop of the SB Physics.

  17. Oral Ingestion of Collagen Hydrolysate Leads to the Transportation of Highly Concentrated Gly-Pro-Hyp and Its Hydrolyzed Form of Pro-Hyp into the Bloodstream and Skin.

    Science.gov (United States)

    Yazaki, Misato; Ito, Yukihiko; Yamada, Masayoshi; Goulas, Spyros; Teramoto, Sachiyuki; Nakaya, Masa-Aki; Ohno, Shigeo; Yamaguchi, Kohji

    2017-03-22

    Collagen hydrolysate is a well-known dietary supplement for the treatment of skin aging; however, its mode of action remains unknown. Previous studies have shown that the oral ingestion of collagen hydrolysate leads to elevated levels of collagen-derived peptides in the blood, but whether these peptides reach the skin remains unclear. Here, we analyzed the plasma concentration of collagen-derived peptides after ingestion of high tripeptide containing collagen hydrolysate in humans. We identified 17 types of collagen-derived peptides transiently, with a particular enrichment in Gly-Pro-Hyp. This was also observed using an in vivo mouse model in the plasma and skin, albeit with a higher enrichment of Pro-Hyp in the skin. Interestingly, this Pro-Hyp enrichment in the skin was derived from Gly-Pro-Hyp hydrolysis, as the administration of pure Gly-Pro-Hyp peptide led to similar results. Therefore, we propose that functional peptides can be transferred to the skin by dietary supplements of collagen.

  18. Estado de conocimiento de las concentraciones de cadmio, mercurio y plomo en organismos acuáticos de Venezuela - Current state of knowledge of the concentrations of cadmium, mercury and lead from aquatic organisms of Venezuela

    Directory of Open Access Journals (Sweden)

    Salazar Lugo, Raquel

    2009-11-01

    Full Text Available ResumenEn Venezuela, la contaminación por metales pesados está relacionadacon el desarrollo de la industria siderúrgica y petrolera, así como a la explotación indiscriminada de otros metales como el oro. Está bastante documentada la contaminación del lago de Maracaibo dado al desarrollo en sus cercanías de actividades urbanas, industriales, mineras y agropecuarias; del lago de Valencia, del río Tuy, Orinoco y Manzanares, entre otros En este trabajo se revisa el estado de conocimiento, en los últimos 10 años, de la concentración de plomo, cadmio y mercurio en especies acuáticas de diferentes áreas del País.SummaryContamination due to trace metals in Venezuela is related withindiscriminate exploitation of metals like gold, transport of river runoff, oil and siderurgica industries and urban zones. The Tuy, Orinoco, Tigre, Manzanares rivers and others basins as Valencia and Maracaibo lakes has been reported as polluted for many years. In this work, we reviewed the state of knowledge, in the last 10 years, of metals concentrations specially lead, cadmium and mercury, in aquatic species from diverse areas of country.

  19. Lead effects on fungi

    Energy Technology Data Exchange (ETDEWEB)

    Gullino, M.L.; Fiussello, N.

    1976-01-01

    Addition of 0.01M lead nitrate to media caused complete inhibition of most of a group of 80 strains of fungi of several genera. Those which did grow at all had an extended lag period in comparison to controls. At 0.001M all the fungi grew, but had thinner-than-normal mycelia and delayed fruiting body formation. Fusarium species and members of Class Basidiomycetes were among the most sensitive, and Penicillium and Aspergillus species were the most tolerant. Lead uptake rates varied positively with lead nitrate concentration in the media. 9 references, 2 figures, 3 tables.

  20. Who Leads China's Leading Universities?

    Science.gov (United States)

    Huang, Futao

    2017-01-01

    This study attempts to identify the major characteristics of two different groups of institutional leaders in China's leading universities. The study begins with a review of relevant literature and theory. Then, there is a brief introduction to the selection of party secretaries, deputy secretaries, presidents and vice presidents in leading…

  1. Characterization of naturally occurring airborne diacetyl concentrations associated with the preparation and consumption of unflavored coffee

    Directory of Open Access Journals (Sweden)

    Jennifer S. Pierce

    2015-01-01

    Full Text Available Diacetyl, a suspected cause of respiratory disorders in some food and flavorings manufacturing workers, is also a natural component of roasted coffee. We characterized diacetyl exposures that would plausibly occur in a small coffee shop during the preparation and consumption of unflavored coffee. Personal (long- and short-term and area (long-term samples were collected while a barista ground whole coffee beans, and brewed and poured coffee into cups. Simultaneously, long-term personal samples were collected as two participants, the customers, drank one cup of coffee each per h. Air sampling and analyses were conducted in accordance with OSHA Method 1012. Diacetyl was detected in all long-term samples. The long-term concentrations for the barista and area samples were similar, and ranged from 0.013–0.016 ppm; long-term concentrations for the customers were slightly lower and ranged from 0.010–0.014 ppm. Short-term concentrations ranged from below the limit of detection (<0.0047 ppm–0.016 ppm. Mean estimated 8 h time-weighted average (8 h TWA exposures for the barista ranged from 0.007–0.013 ppm; these values exceed recommended 8 h TWA occupational exposure limits (OELs for diacetyl and are comparable to long-term personal measurements collected in various food and beverage production facilities. The concentrations measured based on area sampling were comparable to those measured in the breathing zone of the barista, thus exceedances of the recommended OELs may also occur for coffee shop workers who do not personally prepare coffee (e.g., cashier, sanitation/maintenance. These findings suggest that the practicality and scientific basis of the recommended OELs for diacetyl merit further consideration.

  2. Leading Cities

    DEFF Research Database (Denmark)

    Pogner, Karl-Heinz

    2017-01-01

    and technical engineering; Smart Cities) is very prominent in the traditional mass media discourse, in PR / PA of tech companies and traditional municipal administrations; whereas the second one (participation; Livable Cities) is mostly enacted in social media, (local) initiatives, movements, (virtual......) communities, new forms of urban governance in municipal administration and co-competitive city networks. Both forms seem to struggle for getting voice and power in the discourses, negotiations, struggles, and conflicts in Urban Governance about the question how to manage or lead (in) a city. Talking about...

  3. Growth at elevated CO2 concentrations leads to modified profiles of secondary metabolites in tobacco cv. SamsunNN and to increased resistance against infection with potato virus Y.

    Science.gov (United States)

    Matros, Andrea; Amme, Steffen; Kettig, Barbara; Buck-Sorlin, Gerhard H; Sonnewald, Uwe; Mock, Hans-Peter

    2006-01-01

    The effect of elevated CO2 concentrations on the levels of secondary metabolites was investigated in tobacco plants grown under two nitrogen supply (5 and 8 mM NH4NO3) and CO2 conditions (350 and 1000 p.p.m.) each. High CO2 resulted in a dramatic increase of phenylpropanoids in the leaves, including the major carbon-rich compound chlorogenic acid (CGA) and the coumarins scopolin and scopoletin at both nitrogen fertilizations. This was accompanied by increased PAL activity in leaves and roots, which was even higher at the lower nitrogen supply. Hardly any change was observed for the structural phenolic polymer lignin and the sesquiterpenoid capsidiol. In contrast, elevated CO2 led to clearly decreased levels of the main nitrogen-rich constituent nicotine at the lower N-supply (5 mM NH4NO3) but not when plants were grown at the higher N-supply (8 mM NH4NO3). Inoculation experiments with potato virus Y (PVY) were used to evaluate possible ecological consequences of elevated CO2. The titre of viral coat-protein was markedly reduced in leaves under these conditions at both nitrogen levels. Since PR-gene expression and free salicylic acid (SA) levels remained unchanged at elevated CO2, we suggest that the accumulation of phenylpropanoids, for example, the major compound CGA and the coumarins scopolin and scopoletin may result in an earlier confinement of the virus at high CO2. Based on our results two final conclusions emerge. First, elevated CO2 leads to a shift in secondary metabolite composition that is dependent on the availability of nitrogen. Second, changes in the pool of secondary metabolites have important consequences for plant-pathogen interactions as shown for PVY as a test organism.

  4. Lead-210 contamination

    Energy Technology Data Exchange (ETDEWEB)

    Gray, P. [Peter Gray and Associates, Tulsa, OK (United States)

    1997-12-31

    Nearly all scrap dealers, smelters and other recyclers routinely monitor for radioactivity in shipments entering their facility. These sensitive radiation gate monitors easily detect radium-226 and most other radioactive nuclides. However, the type of detector normally used, sodium iodide scintillation crystals, will not detect the low energy gamma radiation emitted by lead-210 and its progeny. Since lead-210 is a common radioactive contaminant in certain industries, contaminated scrap metal from these industries may avoid detection at the recycler. Lead-210 is a decay product of radon-222 which is produced in small concentrations with natural gas. As the natural gas liquids, particularly ethane and propane, are separated from the natural gas, the radon concentrates in the ethane/propane fraction. The natural gas industry, particularly gas processing facilities and industries using ethane and propane as feed stocks can be significantly contaminated with the radon decay products, especially lead-210, bismuth-210 and polonium-210. Unless the scrap metal is decontaminated before sending to the recycler, the lead-210 contaminated scrap may be processed, resulting in some degree of radioactive contamination of the recycling facilities. Methods of detecting the low energy gamma radiation associated with lead-210 include the pancake G-M detector and the thin crystal-thin window scintillation detector.

  5. Current issues in human lead exposure and regulation of lead.

    Science.gov (United States)

    Davis, J M; Elias, R W; Grant, L D

    1993-01-01

    Concern about lead as a significant public health problem has increased as epidemiological and experimental evidence has mounted regarding adverse health effects at successively lower levels of lead exposure. This concern has led to downward revision of criteria for acceptable blood lead concentrations to the 10 micrograms/dL mark now designated by EPA as a target level for regulatory development and enforcement/clean-up purposes. Much progress has been made in reducing lead exposures during the past 10-15 years, with marked declines evident both in air lead and blood lead concentrations in parallel to the phase-down of lead in gasoline and notable decreases in food lead exposure due to elimination of lead soldered cans by U.S. food processors. With the lessening of exposure from these sources, the importance of other components of multimedia exposure pathways has grown and stimulated increasing regulatory attention and abatement efforts to reduce health risks associated with lead exposure from drinking water, from lead-based paint, and from household dust and soil contaminated by deteriorating paint, smelter emissions, or various other sources. Increasing attention is also being accorded to reduction of occupational lead exposures (including those related to lead abatement activities), with particular concern for protection of men and women during their reproductive years.

  6. High temperature superconductor current leads

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL); Poeppel, Roger B. (Glen Ellyn, IL)

    1995-01-01

    An electrical lead having one end for connection to an apparatus in a cryogenic environment and the other end for connection to an apparatus outside the cryogenic environment. The electrical lead includes a high temperature superconductor wire and an electrically conductive material distributed therein, where the conductive material is present at the one end of the lead at a concentration in the range of from 0 to about 3% by volume, and at the other end of the lead at a concentration of less than about 20% by volume. Various embodiments are shown for groups of high temperature superconductor wires and sheaths.

  7. Lead exposure among lead-acid battery workers in Jamaica.

    Science.gov (United States)

    Matte, T D; Figueroa, J P; Burr, G; Flesch, J P; Keenlyside, R A; Baker, E L

    1989-01-01

    To assess lead exposure in the Jamaican lead-acid battery industry, we surveyed three battery manufacturers (including 46 production workers) and 10 battery repair shops (including 23 battery repair workers). Engineering controls and respiratory protection were judged to be inadequate at battery manufacturers and battery repair shops. At manufacturers, 38 of 42 air samples for lead exceeded a work-shift time-weighted average concentration of 0.050 mg/m3 (range 0.030-5.3 mg/m3), and nine samples exceeded 0.50 mg/m3. Only one of seven air samples at repair shops exceeded 0.050 mg/m3 (range 0.003-0.066 mg/m3). Repair shop workers, however, had higher blood lead levels than manufacturing workers (65% vs. 28% with blood lead levels above 60 micrograms/dl, respectively). Manufacturing workers had a higher prevalence of safe hygienic practices and a recent interval of minimal production had occurred at one of the battery manufacturers. Workers with blood lead levels above 60 micrograms/dl tended to have higher prevalences of most symptoms of lead toxicity than did workers with lower blood lead levels, but this finding was not consistent or statistically significant. The relationship between zinc protoporphyrin concentrations and increasing blood lead concentrations was consistent with that described among workers in developed countries. The high risk of lead toxicity among Jamaican battery workers is consistent with studies of battery workers in other developing countries.

  8. The Cycle of Lead Concentration in BF and Its Suppression Measures%高炉中铅元素的循环富集及其抑制措施

    Institute of Scientific and Technical Information of China (English)

    薛飞

    2014-01-01

    Through balance calculation of lead in the raw material of BF charging and spending material, using scanning electron microscopy(sem)and energy spectrum analyzer for the BF tuyere area drops of liquid metal in the sample analysis, the behavior of lead in BF are analyzed. For enrichment of the cycle of lead to the adverse effects of blast furnace smelting, some measures included reducing lead content charged raw materials, increasing the exhausting rate of lead and installing exhausting lead hole in BF were put out.%通过对高炉入炉原料和支出物料铅元素平衡计算,采用扫描电镜和能谱分析仪对高炉风口部位滴出的金属液进行系统的取样分析研究,分析了高炉生产中铅的行为规律。针对铅元素的循环富集给高炉冶炼带来的不利影响,提出了减少入炉原料的铅含量、提高高炉排铅率、在高炉内设置排铅孔的抑制措施。

  9. Pesticide exposure assessment in flowing waters – results for predicted environmental concentrations in some brooks in Germany

    DEFF Research Database (Denmark)

    Trapp, M.T.; Guerniche, D.G.; Bach, M.B.

    2010-01-01

    was to predict initial environmental concentrations in flowing water bodies after spray drift exposure. Based on this the downstream development of these concentrations over space and time with regard to dispersion processes was simulated (PECtwa, Time over Threshold). An adequate GIS-based software......-environment and a functional workflow have been developed which make use of high and medium resolution geodata (water bodies, application areas, mitigating vegetation) and implement results of the relevant scientific work. The observed spatial entity here, as a first step, is a brook in the Hallertau Region, Germany...... TWA strongly correlated to the neighbouring application areas. Differences between the databases can be stated: PECtwa(1h) at 3150 m from the source simulated on ATKIS data amounts to 18 µg/l (Max: 18.5 µg/l at 6000 m), whereby the value calculated on HR-data is 11.7 µg/l (Max: 18 µg/l at 4250 m...

  10. [XANES study of lead speciation in duckweed].

    Science.gov (United States)

    Chu, Bin-Bin; Luo, Li-Qiang; Xu, Tao; Yuan, Jing; Sun, Jian-Ling; Zeng, Yuan; Ma, Yan-Hong; Yi, Shan

    2012-07-01

    Qixiashan lead-zinc mine of Nanjing was one of the largest lead zinc deposits in East China Its exploitation has been over 50 years, and the environmental pollution has also been increasing. The lead concentration in the local environment was high, but lead migration and toxic mechanism has not been clear. Therefore, biogeochemistry research of the lead zinc mine was carried out. Using ICP-MS and Pb-L III edge XANES, lead concentration and speciation were analyzed respectively, and duckweed which can tolerate and enriched heavy metals was found in the pollution area. The results showed that the lead concentration of duckweed was 39.4 mg x kg(-1). XANES analysis and linear combination fit indicated that lead stearate and lead sulfide accounted for 65% and 36.9% respectively in the lead speciation of duckweed, suggesting that the main lead speciation of duckweed was sulfur-containing lead-organic acid.

  11. Chronic lead poisoning in horses

    Energy Technology Data Exchange (ETDEWEB)

    Knight, H.D.; Burau, R.G.

    1973-05-01

    Chronic lead poisoning in horses was manifested as anorexia, loss of body weight, muscular weakness, anemia, laryngeal hemiplegia, and, terminally, inhalation pneumonia. Some deaths were sudden and unexplained. The lead content in liver specimens from 10 horses was greater than that considered indicative of lead intoxication; however, the lead content of blood was equivocal. The most conclusive laboratory finding was increased urine lead concentration after chelation therapy. The concentration of lead in a sample of vegetation considered to be representative of what a horse would eat if he was grazing in the area sampled was 325 ppM (oven-dry basis). It was determined that a 450-kg horse grazing grass of this lead content would consume 2.9 Gm of lead daily (6.4 mg/kg of body weight), an amount considered toxic for horses. Leaching lowered the calcium content of the forage but failed to reduce the lead concentration of the plants significantly, thus opening the possibility that winter rains might have influenced the onset of poisoning. Airborne fallout from a nearby lead smelter was proposed as the primary mode of pasture contamination.

  12. Contribution of solid fuel, gas combustion, or tobacco smoke to indoor air pollutant concentrations in Irish and Scottish homes

    Energy Technology Data Exchange (ETDEWEB)

    Semple, S.; Garden, C. (Univ. of Aberdeen. Scottish Centre for Indoor Air, Div. of Applied Health Sciences (United Kingdom)); Galea, K.S.; Cowie, H.; Hurley, J.F.; Sanchez-Jimenez, A. (Scottish Centre for Indoor Air. Institute of Occupational Medicine, Edinburgh (United Kingdom)); Whelan, P.; Coggins, M. (National Univ. of Ireland Galway (Ireland)); Thorne, P.S. (Univ. of Iowa. Environmental Health Sciences Research Center, Iowa City, IA (United States)); Ayres, J.G. (Univ. of Birmingham. Institute of Occupational and Environmental Medicine (United Kingdom))

    2012-06-15

    There are limited data describing pollutant levels inside homes that burn solid fuel within developed country settings with most studies describing test conditions or the effect of interventions. This study recruited homes in Ireland and Scotland where open combustion processes take place. Open combustion was classified as coal, peat, or wood fuel burning, use of a gas cooker or stove, or where there is at least one resident smoker. Twenty-four-hour data on airborne concentrations of particulate matter <2.5 mu in size (PM{sub 2.5}), carbon monoxide (CO), endotoxin in inhalable dust and carbon dioxide (CO{sub 2}), together with 2-3 week averaged concentrations of nitrogen dioxide (NO{sub 2}) were collected in 100 houses during the winter and spring of 2009-2010. The geometric mean of the 24-h time-weighted-average (TWA) PM{sub 2.5} concentration was highest in homes with resident smokers (99 mu/m3- much higher than the WHO 24-h guidance value of 25 mu/m3). Lower geometric mean 24-h TWA levels were found in homes that burned coal (7 mu/m3) or wood (6 mu/m3) and in homes with gas cookers (7 mu/m3). In peat-burning homes, the average 24-h PM{sub 2.5} level recorded was 11 mu/m3. Airborne endotoxin, CO, CO{sub 2}, and NO{sub 2} concentrations were generally within indoor air quality guidance levels. (Author)

  13. The School Performance of BoyS from rural SchoolS in lower SileSia in The lighT of lead concenTraTion in Blood

    Directory of Open Access Journals (Sweden)

    Grzegorz Żurek

    2012-03-01

    Full Text Available Research conducted in many research centers all over the world indicate health threats resulting from the presence of lead in the blood gradually decreases to the permissible amount. Lead accumulation in a living organism results in adverse changes in different body systems, symptoms of which include various behavioral changes. They can be reflected in grades obtained by the child at school. The aim of this paper was to establish whether the blood lead level diversify the boys in the respect of their school performance during consecutive years of primary education. The amount of lead in blood of 94 boys at the age of 10 has been measured; subsequently, the group of subjects was divided into two subgroups; the first one (termed in this paper „L” comprised students whose Pb-B level was lower than 6 μg/dl (4,846 μg/dl on average and the second one (termed „H” comprised boys whose blood level exceeded 6 μg/dl (9,256 μg/dl on average. Academic performance in the arts, scientific subjects, geography and natural science in respective groups was assessed. Said procedure was replicated in respective subgroups after a year when the subjects were 11 years old. It was ascertained that the academic performance of the boys with higher blood lead levels deteriorated in scientific subjects and tended to worsen also in other school subject groups. Performance of the students whose blood lead level was lower in the initial examination remained unchanged or improved.

  14. Lead behavior in abalone shell

    Science.gov (United States)

    Hirao, Yoshimitsu; Matsumoto, Akikazu; Yamakawa, Hiroshi; Maeda, Masaru; Kimura, Kan

    1994-08-01

    In order to gain information about the behavior of heavy metals in biological assimilation processes in a marine food chain and to investigate the possibility that lead pollution in a marine environment can be estimated by measurement of a small number of key materials from such a food chain, muscle and shell were analyzed from abalone ( Haliotis) from a shallow water locality in a Japanese coastal region. Lead concentrations in muscle were about 26 ppb for abalone of approximately 3 years old and decreased systematically with increasing age of animals sampled, to about 3.3 ppb for a specimen approximately 8 years old. Lead concentrations in shell material gradually decreased also, from 150 ppb to 82 ppb in the oldest specimen. The decrease of concentration in tissues with increasing age indicates that a mechanism for exclusion of lead during tissue growth becomes more efficient with age. Along the food chain in which abalone is the final stage, lead was enriched at the first stage, from seawater to algae, by a factor of 100. Lead was diminished at all subsequent stages of the chain. Tissue of artificially cultured abalone had four times higher lead values compared to abalone grown in natural conditions, and this appears to reflect the fact that lead concentration was three times higher in seawater in the cultured environment.

  15. Concentration device

    DEFF Research Database (Denmark)

    2013-01-01

    A concentration device (2) for filter filtration concentration of particles (4) from a volume of a fluid (6). The concentration device (2) comprises a filter (8) configured to filter particles (4) of a predefined size in the volume of the fluid (6). The concentration device (2) comprises...

  16. Concentrated Ownership

    DEFF Research Database (Denmark)

    Rose, Caspar

    2014-01-01

    , especially minority shareholders. Concentrated ownership is associated with benefits and costs. Concentrated ownership may reduce agency costs by increased monitoring of top management. However, concentrated ownership may also provide dominating owners with private benefits of control.......This entry summarizes the main theoretical contributions and empirical findings in relation to concentrated ownership from a law and economics perspective. The various forms of concentrated ownership are described as well as analyzed from the perspective of the legal protection of investors...

  17. Lead levels of Culex mosquito larvae inhabiting lead utilizing factory

    Institute of Scientific and Technical Information of China (English)

    Kitvatanachai S; Apiwathnasorn C; Leemingsawat S; Wongwit W; Overgaard HJ

    2011-01-01

    Objective: To determine lead level primarily in Culex quinquefasciatus (Cx. quinquefasciatus), and Culex gelidus (Cx. gelidus) larvae inhabiting lead consuming factories, and to putatively estimate eco-toxicological impact of effluents from the firms. Methods: Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry (AAS). Results: Cx. quinquefasciatus was the most abundant species followed by Cx. gelidus. The levels of lead were higher in the Cx. quinquefasciatus (1.08-47.47 μg/g), than in the wastewaters surface (0.01-0.78 μg/mL) from the factories or closer areas around factories. Other species were not reaching the criteria for lead determination. Conclusions: The Cx.quinquefasciatus larvae can bio-accumulate the metal and can potentially serve as a biomarker of lead contamination, to complemente conventional techniques.

  18. Dietary exposure to lead in the Netherlands

    NARCIS (Netherlands)

    Boon PE; te Biesebeek JD; van Donkersgoed G; VVH; V&Z

    2017-01-01

    Uptake from the soil is the main route by which lead ends up in food. Lead in soil has its origin in both natural and anthropogenic sources. The lead concentration in food has decreased over the last decennia by the use of unleaded petrol and paint, and the replacement of lead water pipes.

  19. Concentration risk

    Directory of Open Access Journals (Sweden)

    Matić Vesna

    2016-01-01

    Full Text Available Concentration risk has been gaining a special dimension in the contemporary financial and economic environment. Financial institutions are exposed to this risk mainly in the field of lending, mostly through their credit activities and concentration of credit portfolios. This refers to the concentration of different exposures within a single risk category (credit risk, market risk, operational risk, liquidity risk.

  20. Emissions, air concentrations and atmospheric depositions of arsenic, cadmium, lead and nickel in Italy in the last two decades: A review of recent trends in relation to policy strategies adopted locally, regionally and globally

    Directory of Open Access Journals (Sweden)

    Strincone M.

    2013-04-01

    Full Text Available Heavy metals can cause adverse effects to humans, animals and ecosystems due to their bioavailability and toxicity in various environmental compartments. In the last decades, many policy strategies and measures have been taken at global, regional and local level in relation to heavy metals, due to their adverse effects and ability to be transported over long distances. Several EU measures have been adopted in order to control the pollution from heavy metals in the main sectors. This paper will provide an overview of trends of emissions, air concentrations and atmospheric depositions of heavy metals in Italy and of the main relevant EU legislation and its goals (Directives on paints, batteries, industrial emissions, etc. together with policies adopted at Italian level.

  1. Comparative analysis of concentrations of lead, cadmium and mercury in cord blood, maternal blood, and breast milk, as well as persistent chlorinated hydrocarbons in maternal milk samples from Germany and Iran; Vergleichende Untersuchungen ueber die Blei-, Cadmium- und Quecksilberkonzentrationen im Nabelschnurblut, im muetterlichen Blut und in der Frauenmilch sowie ueber einige persistente Organochlorverbindungen in der Milch deutscher und iranischer Muetter

    Energy Technology Data Exchange (ETDEWEB)

    Javanmardi, F.

    2001-07-01

    The concentration of the heavy metals lead, cadmium and mercury in cord blood, maternal blood and breast milk has been studied. Lead and cadmium were analyzed by atomic absorption spectrometry. Mercury was determined using the flow-injection hydride technique. According to the concentrations of heavy metals and chlorinated hydrocarbons we ascertained for the region of Rendsburg, the toxic risk for infants relative to the consumption of contaminated maternal milk can be viewed as very slight. (orig.) [German] Ziel der Arbeit war es, die aktuelle Schwermetallbelastung des Nabelschnurblutes, des muetterlichen Blutes und der Muttermilch zu untersuchen. Die Bestimmung von Blei und Cadmium erfolgte mit Hilfe der Atomabsorptionsspektrometrie. Quecksilber wurde mittels der Fliessinjektions-Hydridtechnik bestimmt. Nach den von uns ermittelten Schwermetall- bzw. Chlorkohlenwasserstoffkonzentrationen fuer die Region Rendsburg kann das mit dem Verzehr kontaminierter Muttermilch verbundene toxische Risiko fuer den Saeugling als sehr gering eingeschaetzt werden. (orig.)

  2. Lead sources in human diet in Greenland

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Johansen, Poul; Mulvad, Gert

    2004-01-01

    Although blood lead levels have declined in Greenland, they are still elevated despite the fact that lead levels in the Greenland environment are very low. Fragments of lead shot in game birds have been suggested as an important source of dietary exposure, and meals of sea birds, particularly eider......, contain high concentrations of lead. In a cross-sectional population survey in Greenland in 1993-1994, blood lead adjusted for age and sex was found to be associated with the reported consumption of sea birds. Participants reporting less than weekly intake of sea birds had blood lead concentrations...... of approximately 75 microg/L, whereas those who reported eating sea birds several times a week had concentrations of approximately 110 microg/L, and those who reported daily intake had concentrations of 170 microg/L (p = 0.01). Blood lead was not associated with dietary exposure to other local or imported food...

  3. Lead Poisoning Prevention Tips

    Science.gov (United States)

    ... or removed safely. How are children exposed to lead? Lead-based paint and lead contaminated dust are ... What can be done to prevent exposure to lead? It is important to determine the construction year ...

  4. Lead (Pb) Air Pollution

    Science.gov (United States)

    ... States Environmental Protection Agency Search Search Lead (Pb) Air Pollution Share Facebook Twitter Google+ Pinterest Contact Us As ... and protect aquatic and terrestrial ecosystems. Lead (Pb) Air Pollution Lead Air Pollution Basics How does lead get ...

  5. 电感耦合等离子体质谱法分析大鼠血、毛发及脏器中铅浓度及同位素比值%Determination of Lead Concentration and Isotopic Ratios of Blood, Hair and Tissues in Rats by Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    曾静; 闫赖赖; 欧阳荔; 王京宇

    2011-01-01

    建立了电感耦合等离子体质谱(ICP-MS)同时测定铅浓度及同位素比值的方法,并应用于染毒大鼠血、毛发及组织脏器测定,以考察大鼠体内铅浓度及同位素比值分布情况及染毒剂量对其的影响.标准物质牛全血铅浓度测定结果为(278±4) μg/L,在证书标准值(283±18)μg/L范围内;测定10 μg/L Pb标准溶液的RSD肾>毛>肝>全血,各组织脏器中铅同位素指纹亦有不同.血铅相对于毛发铅更适于作为反映体内铅蓄积程度的生物标志物.%A method was developed to simultaneously determine lead concentration and lead isotopic ratios in blood, hair, and other organs of lead exposed rats by inductively coupled plasma mass spec-trometry(ICP-MS). The measurement value of lead concentration in standard material is (278±4) μg/L that is in the range of certified value (283±18) μg/L, and the RSDs of Pb concentration, ratio 204Pb/206Pb, 207Pb/206Pb and 208Pb/206Pb of in the determination of 10 μg/L Pb standard solution were less than 0. 7%, 0. 3%, 0. 15% and 0. 15%, respectively. It was found that RSD of isotopic ratios is stable when Pb concentration is more than 8 μg/L; The concentration calculated by sum of of all Pb isotopes is more accurate and reasonable than that only by 208Pb. The measured results of samples from rats tissues show that there is a selective accumulation of Pb in different tissues and organs, Pb concentration from high to low is in femur, kidney, hair, liver and blood. Blood is more suitable than hair for biomarker to reflect inner Pb accumulation.

  6. Lead concentration and allocation in vegetable crops grown in a soil contaminated by battery residues Teores e alocação de chumbo em hortaliças cultivadas em solo contaminado por resíduos de baterias

    Directory of Open Access Journals (Sweden)

    Francisco de S Lima

    2009-09-01

    Full Text Available Lead (Pb is a very stable metal in soil and is highly toxic to humans and animals. Exposure to Pb occurs via inhalation of particles from industry and soil, as well as household dust, water, and contaminated food. A greenhouse experiment was carried out to evaluate Pb contents and allocation in vegetable crops grown in a soil contaminated by battery recycling wastes. Eight plant species were studied: tomato, sweet pepper, beet, carrot, cabbage, green collards, eggplant, and okra. The experiment was set up in blocks at random with four replicates. The results showed that carrot, green collards, beet, and okra were the most Pb tolerant species, while the others were very Pb-sensitive, since they did not complete their cycle. The decreasing order for Pb accumulation in the vegetables crops was: carrot > okra > tomato > eggplant > sweet pepper > green collards > cabbage > beet. Taking into account the Pb allocation in plants, the order was: root > stems > leaves > edible parts. Although carrot translocated the lowest Pb amount into the edible part, such level exceeded the legal limit.O chumbo (Pb é um elemento extremamente estável no solo e altamente tóxico para seres humanos e animais. A contaminação com chumbo geralmente ocorre pela exposição decorrente da inalação de partículas oriundas de indústrias ou do solo, ou ainda, pela ingestão de poeira doméstica, água e alimentos de origem animal e vegetal contaminados. O presente trabalho objetivou avaliar os teores e a alocação de Pb em hortaliças cultivadas em solo contaminado com resíduos de reciclagem de baterias. O experimento foi conduzido em casa-de-vegetação com delineamento experimental em blocos casualizados, com quatro repetições. Os tratamentos corresponderam a oito hortaliças: tomate, pimentão, beterraba, cenoura, repolho, couve manteiga, berinjela e quiabo. Os resultados mostraram que as espécies mais tolerantes ao Pb foram cenoura, couve-manteiga, beterraba e

  7. Lead Aprons Are a Lead Exposure Hazard.

    Science.gov (United States)

    Burns, Kevin M; Shoag, Jamie M; Kahlon, Sukhraj S; Parsons, Patrick J; Bijur, Polly E; Taragin, Benjamin H; Markowitz, Morri

    2017-05-01

    To determine whether lead-containing shields have lead dust on the external surface. Institutional review board approval was obtained for this descriptive study of a convenience sample of 172 shields. Each shield was tested for external lead dust via a qualitative rapid on-site test and a laboratory-based quantitative dust wipe analysis, flame atomic absorption spectrometry (FAAS). The χ(2) test was used to test the association with age, type of shield, lead sheet thickness, storage method, and visual and radiographic appearance. Sixty-three percent (95% confidence interval [CI]: 56%-70%) of the shields had detectable surface lead by FAAS and 50% (95% CI: 43%-57%) by the qualitative method. Lead dust by FAAS ranged from undetectable to 998 μg/ft(2). The quantitative detection of lead was significantly associated with the following: (1) visual appearance of the shield (1 = best, 3 = worst): 88% of shields that scored 3 had detectable dust lead; (2) type of shield: a greater proportion of the pediatric patient, full-body, and thyroid shields were positive than vests and skirts; (3) use of a hanger for storage: 27% of shields on a hanger were positive versus 67% not on hangers. Radiographic determination of shield intactness, thickness of interior lead sheets, and age of shield were unrelated to presence of surface dust lead. Sixty-three percent of shields had detectable surface lead that was associated with visual appearance, type of shield, and storage method. Lead-containing shields are a newly identified, potentially widespread source of lead exposure in the health industry. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  8. Drowning in concentrated syrup.

    Science.gov (United States)

    Talwar, Vandana; Sood, Nishant; Verma, P K

    2009-04-01

    Drowning is one of the two leading causes of accidental death in children. Most of the cases can be attributed to fresh or salt water drowning. We report an unusual case of acute respiratory distress syndrome in a one year old child following drowning in concentrated sugar syrup, in whom timely intervention and early supportive therapy resulted in a favorable outcome.

  9. Concentrating Radioactivity

    Science.gov (United States)

    Herrmann, Richard A.

    1974-01-01

    By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

  10. Lead and the Romans

    Science.gov (United States)

    Reddy, Aravind; Braun, Charles L.

    2010-01-01

    Lead poisoning has been a problem since early history and continues into modern times. An appealing characteristic of lead is that many lead salts are sweet. In the absence of cane and beet sugars, early Romans used "sugar of lead" (lead acetate) to sweeten desserts, fruits, and sour wine. People most at risk would have been those who…

  11. Lead and the Romans

    Science.gov (United States)

    Reddy, Aravind; Braun, Charles L.

    2010-01-01

    Lead poisoning has been a problem since early history and continues into modern times. An appealing characteristic of lead is that many lead salts are sweet. In the absence of cane and beet sugars, early Romans used "sugar of lead" (lead acetate) to sweeten desserts, fruits, and sour wine. People most at risk would have been those who consumed the…

  12. Jinde Lead lead smelting project starts construction

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>On Dec.20,the lead smelting project of Jiangxi Jinde Lead started construction in Dexin as a technical renovation project on environmental treatment of Jiangxi Metallurgical Group.The project is the one with the largest investment of Provincial Metallurgical Group in non-ferrous

  13. Lead - nutritional considerations

    Science.gov (United States)

    Lead poisoning - nutritional considerations; Toxic metal - nutritional considerations ... Markowitz M. Lead poisoning. In: Kliegman RM, Behrman RE, Jenson HB, ... Emergency Medicine: Concepts and Clinical Practice . 8th ed. ...

  14. Lead- induced genotoxicity in wheat

    Directory of Open Access Journals (Sweden)

    Elena Truta

    2010-02-01

    Full Text Available The changes induced in cytogenetic parameters from root meristems of Triticum aestivum cv. Maruca seedlings have been studied after treatment with lead acetate and lead nitrate solutions, at four concentrations (10, 25, 50, 100 μM containing 2.07, 5.18, 10.36, respectively 20.72 μg ml-1 Pb2+. Lead induced mitosis disturbances in root meristematic cells of wheat seedlings, expressed mainly in decrease of mitotic index and changes in preponderance of division phases. This heavy metal has genotoxic effects, expressed in the occurrence of many chromosomal aberrations in all Pb2+ treated variants. Pb2+ nitrate shows a more pronounced genotoxic potential than lead acetate trihydrate.

  15. Cryogenic current leads

    Energy Technology Data Exchange (ETDEWEB)

    Zizek, F.

    1982-01-01

    Theoretical, technical and design questions are examined of cryogenic current leads for SP of magnetic systems. Simplified mathematical models are presented for the current leads. To illustrate modeling, the calculation is made of the real current leads for 500 A and three variants of current leads for 1500 A for the enterprise ''Shkoda.''

  16. Learn about Lead

    Science.gov (United States)

    ... old and younger are most susceptible to the effects of lead. Children Even low levels of lead in the blood ... simple blood test to check you or your child for lead exposure. You may also want to test your home for sources ... and Technology Lead Laws and Regulations Outreach and Grants En ...

  17. Correlation between airborne manganese concentration at the workstations in the iron foundry and manganese concentration in workers' blood.

    Science.gov (United States)

    Mirmohammadi, Seyedtaghi; Moghaddasi, Yosef; Yazdani, Jamshid; Yousefinejad, Razyeh; Esfandyari, Yahya; Gorgani, Mohsen; Habibpour, Manijeh

    2017-06-27

    Manganese (Mn) used as raw material for melting process in the ferrous foundry is considered as hazardous neurotoxic substance because it accumulates in the central nervous system and may cause neurological disorders. The furnace-men and melting department workers are potentially exposed to manganese particles or fume in the workplace. The objective of the research has been to investigate the sources and levels of manganese exposure in the foundry by correlation of blood-manganese (B-Mn) and air-manganese (air-Mn) measurement. Air-Mn and Mn of blood serum were measured involving workers who worked in a big-sized foundry during 1 year. The standard method of the Occupational Safety and Health Administration (OSHA) ID-121 was used for air and blood assessment and atomic absorption spectroscopy (AAS) was carried out for air and blood sample analysis. The air sampling results have revealed that there is a high exposure to manganese (4.5 mg/m3) in the workplace as compared to the National Institute for Occupational Safety and Health's (NIOSH) time weighted average (the reference time-weighted average (TWA) = 1 mg/m3). The average blood serum Mn concentration was 2.745 μg/l for subjects working for shorter than 3 months and 274.85 μg/l for subjects working 3-12 months. Against the research hypothesis there was no correlation between the air-Mn concentration and the B-Mn (serum) level of manganese in the serum of the exposed subjects. It may be due to short time of air sampling of manganese airborne particles, and a real-time monitoring of airborne manganese particles is suggested for any future study. Med Pr 2017;68(4):449-458.

  18. Correlation between airborne manganese concentration at the workstations in the iron foundry and manganese concentration in workers’ blood

    Directory of Open Access Journals (Sweden)

    Seyedtaghi Mirmohammadi

    2017-08-01

    Full Text Available Background: Manganese (Mn used as raw material for melting process in the ferrous foundry is considered as hazardous neurotoxic substance because it accumulates in the central nervous system and may cause neurological disorders. The furnace-men and melting department workers are potentially exposed to manganese particles or fume in the workplace. The objective of the research has been to investigate the sources and levels of manganese exposure in the foundry by correlation of blood-manganese (B-Mn and air-manganese (air-Mn measurement. Material and Methods: Air-Mn and Mn of blood serum were measured involving workers who worked in a big-sized foundry during 1 year. The standard method of the Occupational Safety and Health Administration (OSHA ID-121 was used for air and blood assessment and atomic absorption spectroscopy (AAS was carried out for air and blood sample analysis. Results: The air sampling results have revealed that there is a high exposure to manganese (4.5 mg/m3 in the workplace as compared to the National Institute for Occupational Safety and Health’s (NIOSH time weighted average (the reference time-weighted average (TWA = 1 mg/m3. The average blood serum Mn concentration was 2.745 μg/l for subjects working for shorter than 3 months and 274.85 μg/l for subjects working 3–12 months. Conclusions: Against the research hypothesis there was no correlation between the air-Mn concentration and the B-Mn (serum level of manganese in the serum of the exposed subjects. It may be due to short time of air sampling of manganese airborne particles, and a real-time monitoring of airborne manganese particles is suggested for any future study. Med Pr 2017;68(4:449–458

  19. Lead levels of Culex mosquito larvae inhabiting lead utilizing factory

    Institute of Scientific and Technical Information of China (English)

    Kitvatanachai; S; Apiwathnasorn; C; Leemingsawat; S; Wongwit; W; Overgaard; HJ

    2011-01-01

    Objective:To determine lead level primarily in Culex quinquefasciatus(Cx.quinquefasciatus), and Culex gelidus(Cx.gelidus) larvae inhabiting lead consuming factories,and to putatively estimate eco-toxicological impact of effluents from the firms.Methods:Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry(AAS).Results:Cx.quinquefasciatus was the most abundant species followed by Cx.gelidus.The levels of lead were higher in the Cx.quinquefasciatus(1.08-47.47μg/g),than in the wastewaters surface(0.01-0.78 μg/mL) from the factories or closer areas around factories. Other species were not reaching the.criteria for lead determination.Conclusions:The Cx. quinquefasciatus larvae can bio-accumulate the metal and can potentially serve as a biomarker of lead contamination,to complemente conventional techniques.

  20. Eryptosis in lead-exposed workers

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Dorado, Itzel-Citlalli [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Hernández, Gerardo [Section of Methodology of Science, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Quintanar-Escorza, Martha-Angelica [Faculty of Medicine, UJED, Durango, DGO (Mexico); Maldonado-Vega, María [CIATEC, León, GTO (Mexico); Rosas-Flores, Margarita [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Calderón-Salinas, José-Víctor, E-mail: jcalder@cinvestav.mx [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico)

    2014-12-01

    Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8 μg/dl) and non-exposed workers (4.2 μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca{sup 2+}]{sub i} and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (< 0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca{sup 2+}], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. - Graphical abstract: Fig. 1. (A) Blood lead concentration (PbB) and (B) phosphatidylserine externalization on erythrocyte membranes of non-lead exposed (□) and lead exposed workers (■). Values are mean ± SD. *Significantly different (P < 0.001). - Highlights: • Erythrocytes of lead exposed workers

  1. Tracing changes in atmospheric sources of lead contamination using lead isotopic compositions in Australian red wine.

    Science.gov (United States)

    Kristensen, Louise Jane; Taylor, Mark Patrick; Evans, Andrew James

    2016-07-01

    Air quality data detailing changes to atmospheric composition from Australia's leaded petrol consumption is spatially and temporally limited. In order to address this data gap, wine was investigated as a potential proxy for atmospheric lead conditions. Wine spanning sixty years was collected from two wine regions proximal to the South Australian capital city, Adelaide, and analysed for lead concentration and lead and strontium isotopic composition for source apportionment. Maximum wine lead concentrations (328 μg/L) occur prior to the lead-in-air monitoring in South Australia in the later 1970s. Wine lead concentrations mirror available lead-in-air measurements and show a declining trend reflecting parallel reductions in leaded petrol emissions. Lead from petrol dominated the lead in wine ((206)Pb/(207)Pb: 1.086; (208)Pb/(207)Pb: 2.360) until the introduction of unleaded petrol, which resulted in a shift in the wine lead isotopic composition closer to vineyard soil ((206)Pb/(207)Pb: 1.137; (208)Pb/(207)Pb: 2.421). Current mining activities or vinification processes appear to have no impact with recent wine samples containing less than 4 μg/L of lead. This study demonstrates wine can be used to chronicle changes in environmental lead emissions and is an effective proxy for atmospherically sourced depositions of lead in the absence of air quality data.

  2. Contribution of solid fuel, gas combustion, or tobacco smoke to indoor air pollutant concentrations in Irish and Scottish homes.

    Science.gov (United States)

    Semple, S; Garden, C; Coggins, M; Galea, K S; Whelan, P; Cowie, H; Sánchez-Jiménez, A; Thorne, P S; Hurley, J F; Ayres, J G

    2012-06-01

      There are limited data describing pollutant levels inside homes that burn solid fuel within developed country settings with most studies describing test conditions or the effect of interventions. This study recruited homes in Ireland and Scotland where open combustion processes take place. Open combustion was classified as coal, peat, or wood fuel burning, use of a gas cooker or stove, or where there is at least one resident smoker. Twenty-four-hour data on airborne concentrations of particulate matter<2.5 μm in size (PM2.5), carbon monoxide (CO), endotoxin in inhalable dust and carbon dioxide (CO2), together with 2-3 week averaged concentrations of nitrogen dioxide (NO2) were collected in 100 houses during the winter and spring of 2009-2010. The geometric mean of the 24-h time-weighted-average (TWA) PM2.5 concentration was highest in homes with resident smokers (99 μg/m3--much higher than the WHO 24-h guidance value of 25 μg/m3). Lower geometric mean 24-h TWA levels were found in homes that burned coal (7 μg/m3) or wood (6 μg/m3) and in homes with gas cookers (7 μg/m3). In peat-burning homes, the average 24-h PM2.5 level recorded was 11 μg/m3. Airborne endotoxin, CO, CO2, and NO2 concentrations were generally within indoor air quality guidance levels. Little is known about indoor air quality (IAQ) in homes that burn solid or fossil-derived fuels in economically developed countries. Recent legislative changes have moved to improve IAQ at work and in enclosed public places, but there remains a real need to begin the process of quantifying the health burden that arises from indoor air pollution within domestic environments. This study demonstrates that homes in Scotland and Ireland that burn solid fuels or gas for heating and cooking have concentrations of air pollutants generally within guideline levels. Homes where combustion of cigarettes takes place have much poorer air quality. © 2011 John Wiley & Sons A/S.

  3. Lead and tap water

    Science.gov (United States)

    Water contaminated with lead ... The Environmental Protection Agency (EPA) monitors drinking water in the United States. It requires water suppliers to produce annual water quality reports. These reports include information about lead amounts, and they ...

  4. Lead and Your Baby

    Science.gov (United States)

    ... who works with lead, like in auto repair, construction or in a plant that makes paint, batteries, ... who works with lead, like in auto repair, construction or in a plant that makes paint, batteries, ...

  5. Exposures to lead.

    Science.gov (United States)

    Callan, Anna C; Hinwood, Andrea L

    2011-01-01

    The Pacific Basin Consortium for Environment and Health hosted a workshop on Exposures to Lead. Speakers from Australia and the United States of America addressed current research knowledge on lead exposures and health effects in children, risk assessment and communication issues in dealing with lead exposure sources, different methods for assessing exposure, and the variety of scenarios where lead still remains a pollutant of concern. Mining continues to be a source of lead for many communities, and approaches to reducing exposures in these settings present particular challenges. A Perth Declaration for the Global Reduction of Childhood Lead Exposure was signed by participants of the meeting and is aimed at increasing attention to the need to continue to assess lead in the environment and to develop strategies to reduce lead in the environment and exposure by communities.

  6. Rapid Lead Screening Test

    Science.gov (United States)

    ... Vitro Diagnostics Tests Used In Clinical Care Rapid Lead Screening Test Share Tweet Linkedin Pin it More ... reducing the need for a follow-up visit. Lead Risk Links Centers for Disease Control and Prevention ( ...

  7. Lead Poisoning (For Parents)

    Science.gov (United States)

    ... organs and tissues that need it, thus causing anemia. Most lead ends up in the bone, where it causes ... vomiting or nausea constipation pallor (pale skin) from ... look for lead poisoning or other health problems. Treatment Treatment for ...

  8. NA49: lead-lead collision

    CERN Multimedia

    1996-01-01

    This is an image of an actual lead ion collision taken from tracking detectors on the NA49 experiment, part of the heavy ion project at CERN. These collisions produce a very complicated array of hadrons as the heavy ions break up. It is hoped that one of these collisions will eventually create a new state of matter known as quark-gluon plasma.

  9. Occupational lead poisoning

    OpenAIRE

    Ramírez, Augusto V; Médico del Trabajo. American College of Occupational and Environmental Medicine.

    2013-01-01

    Lead, a ubiquitous heavy metal, has been found in places as unlikely as Greenland’s fossil ice. Egyptians and Hebrews used it. In Spain, Phoenicians c. 2000 BC worked ores of lead. At the end of the XX century, occupational lead’s poisoning became a public health problem in developed countries. In non-developed countries occupational lead poisoning is still frequent. Diagnosis is directed to recognize lead existence at the labor environment and good clinical and occupational documentation. Di...

  10. SHORT COMMUNICATION REMOVAL OF LEAD IONS FROM ...

    African Journals Online (AJOL)

    a

    44, Rettai Kuli Street, Tondiyar Pet, Chennai –600 081, Tamilnadu, India ... ion exchange [12], membrane separation methods [13] and electro-remediation methods [14] ... The concentration of lead in the solution was 0.1 M. The stock solution.

  11. Lead Poisoning in Children.

    Science.gov (United States)

    Drummond, A. H., Jr.

    1981-01-01

    Early symptoms of lead poisoning in children are often overlooked. Lead poisoning has its greatest effects on the brain and nervous system. The obvious long-term solution to the lead poisoning problem is removal of harmful forms of the metal from the environment. (JN)

  12. Atrioventricular Pacemaker Lead Reversal

    Directory of Open Access Journals (Sweden)

    Mehmet K Aktas, MD

    2007-01-01

    Full Text Available During cardiac surgery temporary epicardial atrial and ventricular leads are placed in case cardiac pacing is required postoperatively. We present the first reported series of patients with reversal of atrioventricular electrodes in the temporary pacemaker without any consequent deleterious hemodynamic effect. We review the electrocardiographic findings and discuss the findings that lead to the discovery of atrioventricular lead reversal.

  13. Lead shot from hunting as a source of lead in human blood

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, Poul [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)]. E-mail: poj@dmu.dk; Pedersen, Henning Sloth [Primary Health Care Center, DK-3900 Nuuk (Greenland); Asmund, Gert [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Riget, Frank [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

    2006-07-15

    This study investigates the relationship between the intake of birds hunted with lead shot and the lead concentration in human blood. Fifty adult men from Nuuk, Greenland took part in the study. From September 2003 to June 2004 they regularly gave blood samples and recorded how many birds they ate. We found a clear relationship between the number of bird meals and blood lead and also a clear seasonal variation. The concentration was highest in mid-winter when bird consumption is at its highest. Blood lead was low (15 {mu}g/L, mean concentration) among the participants reporting not eating birds. Among those reporting to eat birds regularly, blood lead was significantly higher, up to 128 {mu}g/L (mean concentration). Concentrations depended on the frequency of bird meals: the more the bird meals, the higher the resulting blood lead. This clear relationship points to lead shot as the dominating lead source to people in Greenland. - Birds hunted with lead shot and consumed are a source of lead in human blood.

  14. ALICE: Simulated lead-lead collision

    CERN Multimedia

    2003-01-01

    This track is an example of simulated data modelled for the ALICE detector on the Large Hadron Collider (LHC) at CERN, which will begin taking data in 2008. ALICE will focus on the study of collisions between nuclei of lead, a heavy element that produces many different particles when collided. It is hoped that these collisions will produce a new state of matter known as the quark-gluon plasma, which existed billionths of a second after the Big Bang.

  15. Lead poisoning by contaminated flour.

    Science.gov (United States)

    Hershko, C; Eisenberg, A; Avni, A; Grauer, F; Acker, C; Hamdallah, M; Shahin, S; Moreb, J; Richter, E; Weissenberg, E

    1989-01-01

    Between October 1982 and June 1983, 43 patients were identified with symptomatic lead poisoning in three Arab villages of the Nablus district. Because of the clustering of clinical poisoning by household units, investigation was focussed on potential sources common to all members of the households. After excluding water, olive oil and a variety of foodstuff, lead in high concentrations was discovered in locally ground flour in all affected households. The source of poisoning was lead poured into the fissures between the metal housing and the driveshaft of the millstone. Significant lead contamination of freshly ground flour was demonstrated in 23% of the 146 community flour mills operating in West Bank villages. Since the completion of these studies, similar outbreaks of lead poisoning caused by contaminated flourmills have been identified in the Upper Galilee and in Spain. As the methods of milling in the Mediterranean area are similar, a coordinated international effort is needed in order to eliminate this health hazard from countries where similar community stone mills are still in use.

  16. Cleaner concentrates

    Energy Technology Data Exchange (ETDEWEB)

    Boudechiche, S.; Hall, S. [University of Nottingham, Nottingham (United Kingdom)

    1995-06-01

    The desire for higher quality coal products in froth flotation has led to the introduction of a number of novel flotation techniques, including flotation columns, but the benefits of each in relation to the source of the slurry must be evaluated before plant is installed. It was to assess on a laboratory scale the quality of coal flotation concentrates from column flotation of fine coal (-500{mu}m) as an alternative to the traditional conventional agitated cell that this work was carried out. The column developed specifically for this purpose allowed the establishment of an approach to the examination of the flotation response of samples of UK coals (originating from Bolsover, Derbyshies; Rawdon, Leicestershire; and Bilsthorpe, Nottinghamshire). The work indicates the importance of the origin of the feed slurry, since each type of coal exhibits a different flotation response. The observations from the results described in this paper enable an assessment to be made of the merits of column flotation in fine coal treatment. 11 refs., 4 figs., 5 tabs.

  17. Chronic lead intoxication; Chronische Bleiintoxikation

    Energy Technology Data Exchange (ETDEWEB)

    Wieseler, B.; Leng, G. [Duesseldorf Univ. (Germany). Inst. fuer Hygiene; Lenz, S.; Schultz, C. [Klinikum Remscheid GmbH, Remscheid (Germany); Wilhelm, M. [Bochum Univ. (Germany). Inst. fuer Hygiene, Sozial- und Umweltmedizin

    1999-02-01

    The case of a female 68 years old patient is described. Here, a chronic lead intoxication was diagnosed after a two year old medical history with increasing attacks of colic-like abdominal pain often described as life-threatening. After repeated hospitalizations and intensive search for the cause of the symptoms, porphyria and anemia was found to be a sign of a chronic lead poisoning. The blood lead concentrations were always about a level of 600 {mu}g/L. The source of exposure could not be found by now. Neither home inspection nor environmental investigations have shown a recent source of lead intake by the patient. However, a possible occupational source of lead exposure at a blast furnace was established by anamnesis for 1952 to 1962. Thus, osteoporosis induced lead mobilisation was suspected. Noticeable are the results of the six abdominal survey radiographies taken during hospitalization within one year; three radiographies were taken following clinical admission and three before discharge of the patient. In comparison, the course shows a chronic relapsing alimentary supply from metallic particles of unknown genesis. The patient was treated with the sodium salt of 2,3-dimercapto-1-propansulfonic acid (DMPS, Dimaval{sup TM}). She was free of complain afterwards. Following therapy, the blood lead concentrations fell under a level of 400 {mu}m/L, but after several weeks the lead level raised up to the original level of 600 {mu}g/L. (orig.) [Deutsch] Es wird eine 68jaehrige Patientin vorgestellt, bei der nach fast zweijaehriger Krankengeschichte, die gekennzeichnet war durch rezidivierende, teils als lebensbedrohlich geschilderte Bauchkoliken, eine chronische Bleiintoxikation diagnostiziert wurde. Erst nach wiederholten stationaeren Krankenhausaufenthalten mit intensiver Suche nach der Krankheitsursache wurden das Krankheitsbild und die Laborwerte durch Zusatzuntersuchungen ergaenzt, so dass sich in der festgestellten Porphyrie und Anaemie die Diagnose der

  18. Modeling of Blood Lead Levels in Astronauts Exposed to Lead from Microgravity-Accelerated Bone Loss

    Science.gov (United States)

    Garcia, H.; James, J.; Tsuji, J.

    2014-01-01

    Human exposure to lead has been associated with toxicity to multiple organ systems. Studies of various population groups with relatively low blood lead concentrations (adults. Cognitive effects are considered by regulatory agencies to be the most sensitive endpoint at low doses. Although 95% of the body burden of lead is stored in the bones, the adverse effects of lead correlate with the concentration of lead in the blood better than with that in the bones. NASA has found that prolonged exposure to microgravity during spaceflight results in a significant loss of bone minerals, the extent of which varies from individual to individual and from bone to bone, but generally averages about 0.5% per month. During such bone loss, lead that had been stored in bones would be released along with calcium. The effects on the concentration of lead in the blood (PbB) of various concentrations of lead in drinking water (PbW) and of lead released from bones due to accelerated osteoporosis in microgravity, as well as changes in exposure to environmental lead before, during, and after spaceflight were evaluated using a physiologically based pharmacokinetic (PBPK) model that incorporated exposure to environmental lead both on earth and in flight and included temporarily increased rates of osteoporosis during spaceflight.

  19. Lead-Free Piezoelectrics

    CERN Document Server

    Nahm, Sahn

    2012-01-01

    Ecological restrictions in many parts of the world are demanding the elimination of Pb from all consumer items. At this moment in the piezoelectric ceramics industry, there is no issue of more importance than the transition to lead-free materials. The goal of Lead-Free Piezoelectrics is to provide a comprehensive overview of the fundamentals and developments in the field of lead-free materials and products to leading researchers in the world. The text presents chapters on demonstrated applications of the lead-free materials, which will allow readers to conceptualize the present possibilities and will be useful for both students and professionals conducting research on ferroelectrics, piezoelectrics, smart materials, lead-free materials, and a variety of applications including sensors, actuators, ultrasonic transducers and energy harvesters.

  20. Leading to distraction: Driver distraction, lead car, and road environment.

    Science.gov (United States)

    Kountouriotis, G K; Merat, N

    2016-04-01

    Driver distraction is strongly associated with crashes and near-misses, and despite the attention this topic has received in recent years, the effect of different types of distracting task on driving performance remains unclear. In the case of non-visual distractions, such as talking on the phone or other engaging verbal tasks that do not require a visual input, a common finding is reduced lateral variability in steering and gaze patterns where participants concentrate their gaze towards the centre of the road and their steering control is less variable. In the experiments presented here, we examined whether this finding is more pronounced in the presence of a lead car (which may provide a focus point for gaze) and whether the behaviour of the lead car has any influence on the driver's steering control. In addition, both visual and non-visual distraction tasks were used, and their effect on different road environments (straight and curved roadways) was assessed. Visual distraction was found to increase variability in both gaze patterns and steering control, non-visual distraction reduced gaze and steering variability in conditions without a lead car; in the conditions where a lead car was present there was no significant difference from baseline. The lateral behaviour of the lead car did not have an effect on steering performance, a finding which indicates that a lead car may not necessarily be used as an information point. Finally, the effects of driver distraction were different for straight and curved roadways, indicating a stronger influence of the road environment in steering than previously thought.

  1. Task-based lead exposures and work site characteristics of bridge surface preparation and painting contractors.

    Science.gov (United States)

    Virji, M Abbas; Woskie, Susan R; Pepper, Lewis D

    2009-02-01

    This study of bridge painters working for small contractors in Massachusetts investigated the causes of elevated blood lead levels and assessed their exposure to lead. Bridge work sites were evaluated for a 2-week period during which personal and area air samples and information on work site characteristics and lead abatement methods were gathered. Short-duration personal inhalable samples collected from 18 tasks had geometric means (GM) of 3 microg/m(3) to 7286 microg/m(3). Full-shift, time-weighted average (TWA) inhalable samples (>or=6 hours) collected from selected workers and work sites had GMs of 2 microg/m(3) to 15,704 microg/m(3); 80% of samples exceeded the permissible exposure limit (PEL) of 50 microg/m(3), on average by a factor of 30. Area inhalable samples collected from three locations ranged from 2 microg/m(3) to 40,866 microg/m(3) from inside the containment, 2 microg/m(3) to 471 microug/m(3) from a distance of 6 meters from the containment. Seventy nine percent of the area samples from inside the containment exceeded the PEL on average by a factor of 140. Through observations of work site characteristics, opportunities for improving work methods were identified, particularly the institution of engineering controls (which were only occasionally present) and improvement in the design and construction of the containment structure. The high levels of airborne lead exposures indicate a potential for serious exposure hazard for workers and environmental contamination, which can be mitigated through administrative and engineering controls. Although these data were collected over 10 years ago, a 2005 regulatory review by the Occupational Safety and Health Administration (OSHA) of its lead in construction standard reported that elevated lead exposures and blood lead levels, high occurrence of noncompliance with the lead standard, and nonimplementation of newer technology especially among small painting firms employing <10 workers are still widespread. As a

  2. Lead Poison Detection

    Science.gov (United States)

    1976-01-01

    With NASA contracts, Whittaker Corporations Space Science division has developed an electro-optical instrument to mass screen for lead poisoning. Device is portable and detects protoporphyrin in whole blood. Free corpuscular porphyrins occur as an early effect of lead ingestion. Also detects lead in urine used to confirm blood tests. Test is inexpensive and can be applied by relatively unskilled personnel. Similar Whittaker fluorometry device called "drug screen" can measure morphine and quinine in urine much faster and cheaper than other methods.

  3. Fragment-based lead discovery: leads by design.

    Science.gov (United States)

    Carr, Robin A E; Congreve, Miles; Murray, Christopher W; Rees, David C

    2005-07-15

    Fragment-based lead discovery (also referred to as needles, shapes, binding elements, seed templates or scaffolds) is a new lead discovery approach in which much lower molecular weight (120-250 Da) compounds are screened relative to HTS campaigns. Fragment-based hits are typically weak inhibitors (10 microM-mM), and therefore need to be screened at higher concentration using very sensitive biophysical detection techniques such as protein crystallography and NMR as the primary screening techniques, rather than bioassays. Compared with HTS hits, these fragments are simpler, less functionalized compounds with correspondingly lower affinity. However, fragment hits typically possess high 'ligand efficiency' (binding affinity per heavy atom) and so are highly suitable for optimization into clinical candidates with good drug-like properties.

  4. Early umbilical cord clamping contributes to elevated blood lead levels among infants with higher lead exposure.

    Science.gov (United States)

    Chaparro, Camila M; Fornes, Raymond; Neufeld, Lynnette M; Tena Alavez, Gilberto; Eguía-Líz Cedillo, Raúl; Dewey, Kathryn G

    2007-11-01

    To investigate whether infant iron status, modified by umbilical cord clamping time and infant feeding mode, affected infant blood lead concentration at 6 months of age. Participants were a subset of women and their infants randomized to receive early (10 seconds) or delayed (2 minutes) umbilical cord clamping and were monitored to 6 months postpartum in Mexico City. Iron and lead status was analyzed in maternal, placental, and 6-month infant blood samples. Baseline maternal lead exposure data and infant feeding data at 2, 4, and 6 months were collected. In the total sample, maternal blood lead concentration, infant ferritin, and breast-feeding practices predicted infant blood lead concentration. Among infants with higher placental blood lead concentration and breast-fed infants not receiving any iron-fortified formula or milk at 6 months, early clamping increased infant blood lead concentration, an effect mediated in part via decreased infant iron status. Early cord clamping, by decreasing infant iron status, contributes to higher blood lead concentrations at 6 months of age among infants at high risk.

  5. Lead toxicity: Current concerns

    Energy Technology Data Exchange (ETDEWEB)

    Goyer, R.A. (Univ. of Western Ontario, London (Canada))

    1993-04-01

    Over the 20-year period since the first issue of Environmental Health Perspectives was published, there has been considerable progress in the understanding of the potential toxicity of exposure to lead. Many of these advances have been reviewed in published symposia, conferences, and review papers in EHP. This brief review identifies major advances as well as a number of current concerns that present opportunities for prevention and intervention strategies. The major scientific advance has been the demonstration that blood lead (PbB) levels of 10-15 micrograms/dL in newborn and very young infants result in cognitive and behavioral deficits. Further support for this observation is being obtained by prospective or longitudinal studies presently in progress. The mechanism(s) for the central nervous system effects of lead is unclear but involve lead interactions within calcium-mediated intracellular messenger systems and neurotransmission. Effects of low-level lead exposure on blood pressure, particularly in adult men, may be related to the effect of lead on calcium-mediated control of vascular smooth muscle contraction and on the renin-angiotensin system. Reproductive effects of lead have long been suspected, but low-level effects have not been well studied. Whether lead is a carcinogen or its association with renal adenocarcinoma is a consequence of cystic nephropathy is uncertain. Major risk factors for lead toxicity in children in the United States include nutrition, particularly deficiencies of essential metals, calcium, iron, and zinc, and housing and socioeconomic status. A goal for the year 2000 is to reduce prevalence of blood lead levels exceeding 15 micrograms/dL. 97 refs.

  6. Experimental oral lead toxicity in young dogs

    Energy Technology Data Exchange (ETDEWEB)

    Stowe, H.D.; Goyer, R.A.; Krigman, M.M.; Wilson, M.; Cates, M.

    1973-02-01

    Litter-mate male pups were fed a calcium-and-phosphorus-low purified diet with and without 100 ppm of lead as lead acetate from age 6 to 18 weeks. Lead-toxic dogs exhibited cyclic but terminally severe anorexia and cachexia, significant anemia, normoblastocytosis and leukopenia within six weeks, hypoproteinemia, decreased serum albumin, ..cap alpha../sub 1/-globulin, ..beta../sub 2/-globulin, alkaline phosphatase and lactic dehydrogenase 1, elevated serum glutamic oxaloacetic and pyruvic transaminases, delayed closure of the thoracic vertebral epiphyses, lead lines in the distal radii and thoracic spinous processes, enlargement of liver, kidney, and brain, hepatic fatty metamorphosis, focal proximal renal tubular necrosis, hydropic degeneration of spermatognia, and lead inclusion body formation. Approximately 97% of the tissue lead was estimated to be skeletal; the greatest concentration of lead in the brain was found in the occipital gray matter.

  7. Lead Time Study,

    Science.gov (United States)

    1982-05-01

    AD-A128 318 LEAD TIME STUDY (U) ARMY ARMAMENT RESEARCH AND DEVELOPMENT CDMMAND DOVER NJ SYSTEMS ANALYSIS DIV dI-T~~ CHU MAY 82 ARRAA 82- 3/ /l N...EhhEEE--E 1111.0 U 1 - I 1120 1.25I1,,-. 11.6 MICROCOPY RESOLUTION TESI CHARI NATIONAL BUREAU 01 STANDARDt 19t,3 A co LEAD TIME STUDY c*A JULIE CHU MAY...188 D I.-f . . .... .. - r - .. " ’- -~ L - - _ _ __ ARRAA 82-3 LEAD TIME STUDY Prepared by:_ JL CHU Reviewed by:Li t’ ( LAWRENCE J. QWUNI Chief, Sys

  8. Lead and zinc dust depositions from ore trains characterised using lead isotopic compositions.

    Science.gov (United States)

    Kristensen, L J; Taylor, M P; Morrison, A L

    2015-03-01

    This study investigates an unusual source of environmental lead contamination - the emission and deposition of lead and zinc concentrates along train lines into and out of Australia's oldest silver-lead-zinc mine at Broken Hill, Australia. Transport of lead and zinc ore concentrates from the Broken Hill mines has occurred for more than 125 years, during which time the majority was moved in uncovered rail wagons. A significant amount of ore was lost to the adjoining environments, resulting in soil immediately adjacent to train lines elevated with concentrations of lead (695 mg kg(-1)) and zinc (2230 mg kg(-1)). Concentrations of lead and zinc decreased away from the train line and also with depth shown in soil profiles. Lead isotopic compositions demonstrated the soil lead contained Broken Hill ore in increasing percentages closer to the train line, with up to 97% apportioned to the mined Broken Hill ore body. SEM examination showed ceiling dusts collected from houses along the train line were composed of unweathered galena particles, characteristic of the concentrate transported in the rail wagons. The loss of ore from the uncovered wagons has significantly extended the environmental footprint of contamination from local mining operations over an area extending hundreds of kilometres along each of the three train lines.

  9. Lead levels - blood

    Science.gov (United States)

    Blood lead levels ... A blood sample is needed. Most of the time blood is drawn from a vein located on the inside ... may be used to puncture the skin. The blood collects in a small glass tube called a ...

  10. Lead User Innovation

    DEFF Research Database (Denmark)

    Brem, Alexander; Larsen, Henry

    2015-01-01

    , deliver and capture the value of an innovatively new device together. From the perspective of the lead user, we show antecedents and effects of social interaction between organizational actors and the lead user on the development of social capital, especially trust and shared imagination. The second case......User innovation and especially the integration of lead users is a key topic in the innovation management literature of recent years. This paper contributes by providing a rare perspective into what easily could be seen as innovation failure, shown from two perspectives. We show how a lack of shared...... imagination hampers participation and kills innovation between interdependent stakeholders at the threshold between invention and innovation in practice. We present a first case in the fun-sport industry where an external lead user and diverse firm representatives in different functions fail to create...

  11. Nanostructured Lead Compounds in Electrode Materials of a Lead-Acid Battery

    Directory of Open Access Journals (Sweden)

    A.P. Kuzmenko

    2016-11-01

    Full Text Available The nanostructure and phase composition of the electrode material of lead-acid batteries, formed by chemical transformations with involvement of sulfuric acid solutions of various concentrations, water and carbon dioxide have been studied.

  12. Lead in water sources and lead and organochlorines in supplemental food items for the California condor

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — All but one water sample had lead concentrations below the detection limit (Table 1). The water sample collected from Ventucopa, located in Santa Barbara County, had...

  13. Magnesium Diboride Current Leads

    Science.gov (United States)

    Panek, John

    2010-01-01

    A recently discovered superconductor, magnesium diboride (MgB2), can be used to fabricate conducting leads used in cryogenic applications. Dis covered to be superconducting in 2001, MgB2 has the advantage of remaining superconducting at higher temperatures than the previously used material, NbTi. The purpose of these leads is to provide 2 A of electricity to motors located in a 1.3 K environment. The providing environment is a relatively warm 17 K. Requirements for these leads are to survive temperature fluctuations in the 5 K and 11 K heat sinks, and not conduct excessive heat into the 1.3 K environment. Test data showed that each lead in the assembly could conduct 5 A at 4 K, which, when scaled to 17 K, still provided more than the required 2 A. The lead assembly consists of 12 steelclad MgB2 wires, a tensioned Kevlar support, a thermal heat sink interface at 4 K, and base plates. The wires are soldered to heavy copper leads at the 17 K end, and to thin copper-clad NbTi leads at the 1.3 K end. The leads were designed, fabricated, and tested at the Forschungszentrum Karlsruhe - Institut foer Technische Physik before inclusion in Goddard's XRS (X-Ray Spectrometer) instrument onboard the Astro-E2 spacecraft. A key factor is that MgB2 remains superconducting up to 30 K, which means that it does not introduce joule heating as a resistive wire would. Because the required temperature ranges are 1.3-17 K, this provides a large margin of safety. Previous designs lost superconductivity at around 8 K. The disadvantage to MgB2 is that it is a brittle ceramic, and making thin wires from it is challenging. The solution was to encase the leads in thin steel tubes for strength. Previous designs were so brittle as to risk instrument survival. MgB2 leads can be used in any cryogenic application where small currents need to be conducted at below 30 K. Because previous designs would superconduct only at up to 8 K, this new design would be ideal for the 8-30 K range.

  14. COMPREHENSIVE ANALYSIS OF DETERMINING THE CONTENT OF MOLYBDENUM IN THE ROASTING MOLYBDENUM CONCENTRATE BY THE GRAVIMETRIC METHOD OF LEAD MOLYBDATE%全面解析钼酸铅重量法测定焙烧钼精矿中的钼

    Institute of Scientific and Technical Information of China (English)

    张东雯; 任娟玲

    2016-01-01

    本文对钼酸铅重量法测定焙烧钼精矿中的钼的分析原理、分析依据以及反应机理进行了深入全面的探讨和阐述. 以分析方法的操作规程为主线,将操作规程逐步进行解析. 这将为分析工作者更为深入全面地理解分析方法、掌握操作流程以及提高分析方法的可控性、分析结果的精密度和准确度提供理论依据和保障.%Comprehensive explanation and illustration about the analysis principles , analysis basis and reaction mechanism of determining the molybdenum content of roasted molybdenum concentrate by the gravimetric method of lead molybdate was presented .Taking the operating instructions of analytical method as the mainline , the operating instructions were peeled off one by one and gradually analyzed .Theory basis and guarantee would be provided for analytical workers to comprehensively and thoroughly understand the analytical method , master the operation proce-dure as well as improve the controllability of analytical method and the precision and accuracy of analysis results .

  15. Studies on the Analysis of Lead and Silica in Lead Processing Samples

    Directory of Open Access Journals (Sweden)

    R. Ravichandra Babu

    2014-01-01

    Full Text Available In Practice two samples have to be proceeded separately to determine both lead and silica in lead process samples like concentrates, coarse sinter etc. In the present recommended procedure, the lead and silica are precipitated together by using acid fuming, but, instead of using ammonium acetate treatment to separate lead and silica, a mixture of hydrochloric acid-sodium chloride is used to achieve the same purpose. This helps in determine all the components of lead process samples from the same solution without loss of accuracy in any of the components. This method saves considerable time and especially useful for routine analysis in process control lab.

  16. Leading healthcare in complexity.

    Science.gov (United States)

    Cohn, Jeffrey

    2014-12-01

    Healthcare institutions and providers are in complexity. Networks of interconnections from relationships and technology create conditions in which interdependencies and non-linear dynamics lead to surprising, unpredictable outcomes. Previous effective approaches to leadership, focusing on top-down bureaucratic methods, are no longer effective. Leading in complexity requires leaders to accept the complexity, create an adaptive space in which innovation and creativity can flourish and then integrate the successful practices that emerge into the formal organizational structure. Several methods for doing adaptive space work will be discussed. Readers will be able to contrast traditional leadership approaches with leading in complexity. They will learn new behaviours that are required of complexity leaders, along with challenges they will face, often from other leaders within the organization.

  17. [Children exposure to lead in contaminated sites].

    Science.gov (United States)

    Flores-Ramírez, Rogelio; Rico-Escobar, Edna; Núñez-Monreal, Jorge E; García-Nieto, Edelmira; Carrizales, Leticia; Ilizaliturri-Hernández, César; Díaz-Barriga, Fernando

    2012-01-01

    To assess the exposure to lead in children living in various types of contaminated sites. The study was conducted from June 2008 to December 2009 at four sites in Mexico: Avalos metallurgical, Chihuahua; Morales metallurgical, San Luis Potosí (SLP); Trinidad pottery area, Tlaxcala and Cedral mine site, SLP. These sites contain different sources of lead. The metal levels were quantified in outdoor dust and in peripheral blood of children. Lead dust concentrations exceed the National Guidelines for residential soils (400 mg/kg) in a range of values for the four sites from 62 to 5 187 mg/kg. Regarding biological monitoring, the studied children showed maximum lead blood levels of 22 µg/dL in Cedral, 31 µg/dL in Morales, 32 µg/dL in Avalos, and 52 µg/dL in Trinidad. It is important to mention that in all the studied sites, a significative positive correlation was found between blood lead levels and the lead concentrations in dust. These sites are an example of the health risks related to lead exposure in Mexico; therefore, there is an urgent need for a national public health program aimed at reducing lead exposure in vulnerable populations.

  18. El sistema geográfico de información y las concentraciones de plomo en sangre en una población infantil venezolana Usefulness of the Geographic Information System (GIS in the identification of contributing factors to lead blood concentrations in a population of Venezuelan children

    Directory of Open Access Journals (Sweden)

    Carlos Espinosa

    2006-04-01

    Full Text Available OBJETIVO: Identificar los factores ambientales que contribuyen a la concentración de plomo en sangre (Pb-S en niños de Valencia, Venezuela, con la utilización del Sistema Geográfico de Información (SGI. MATERIAL Y MÉTODOS: Estudio analítico ecológico. Población: 60 niños. Información obtenida: demografía, fuentes de emisión de plomo ambiental, niveles de Pb-S. Relación entre variables ambientales y Pb-S mediante análisis de buffer. RESULTADOS: Diferencia significativa entre el Pb-S en varones (11.1±3.1 µg/dl en comparación con las mujeres (9.5±2.7 µg/dl. La media de la Pb-S de los niños residentes en buffer (10.7±3.2 µg/dl fue superior a la media de los restantes (9.9±2.5 µg/dl. Los niños con valores superiores al límite permisible de Pb-S que viven en la zona sur tuvieron una media de Pb-S significativamente superior respecto de los demás. El SGI permitió identificar en el taller de herrería/soldadura la fuente de exposición más cercana a las residencias de los varones. CONCLUSIONES: El SGI hizo posible reconocer fuentes de exposición al plomo y su vínculo con niveles de Pb-S de los niños que viven cerca de dichas fuentes. Se sugiere evaluar con posterioridad los factores adicionales que favorecen el riesgo de exposición.OBJECTIVE: To identify environmental factors that contribute to blood lead levels (BPb in children living in an urban area in Valencia, Venezuela, using a Geographical Information System (GIS as an association tool. MATERIAL AND METHODS: An analytical-ecological study was carried out. Population: 60 children. Data collected: Demography, potential sources of environmental lead and BPb concentrations. An association was made between environmental variables and BPb, using a buffer analysis. RESULTS: There was a statistically significant difference between BPb in males (11.1±3.1 µg/dl compared to females (9.5±2.7 µg/dl. Average BPb of children living within the buffer areas (10.7±3.2 µg

  19. Comparison of the radiological and chemical toxicity of lead

    Energy Technology Data Exchange (ETDEWEB)

    Beitel, G.A.; Mott, S.

    1995-03-01

    This report estimates the worst-case radiological dose to an individual from ingested lead containing picocurie levels of radionuclides and then compares the calculated radiological health effects to the chemical toxic effects from that same lead. This comparison provides an estimate of the consequences of inadvertently recycling, in the commercial market, lead containing nominally undetectable concentrations of radionuclides. Quantitative expressions for the radiological and chemical toxicities of lead are based on concentrations of lead in the blood stream. The result shows that the chemical toxicity of lead is a greater health hazard, by orders of magnitude, than any probable companion radiation dose.

  20. Lead Speciation in remote Mountain Lakes

    Science.gov (United States)

    Plöger, A.; van den Berg, C. M. G.

    2003-04-01

    In natural waters trace metals can become complexed by organic matter. This complexation can change the geochemistry of the metals by preventing them being scavenged, thereby increasing their residence time in the water column. The chemical speciation of trace metals also affects the bioavalability and their toxicological impact on organisms. It is therefore important to determine the chemical speciation of trace metals as well as their concentrations. Mountain lakes have been less studied in the past than other lakes- partly because of their remoteness and partly because they were perceived to be unpolluted and undisturbed. But work so far on mountain lakes has shown that most sites are affected and threatened, for example by transboundary air pollutants like trace metals. One of the important features that distinguishes these lakes from lowland lakes at similar latitudes is the fact that they may be isolated from the atmosphere for six months or more during the winter by a thick ice cover. Also, as these lakes are remote from direct anthropogenic influences, they reflect the regional distribution of pollutants transferred via the atmosphere. For this work, under the framework of the EMERGE (European Mountain lake Ecosystems: Regionalisation, diaGnostic and socio-economic Evaluation) programme, two remote mountain lakes have been studied in detail, with water sampling taking place at different times of the year to investigate possible seasonal differences in lead concentrations and speciation. Results so far have shown that lead-complexing ligand concentrations are in excess to dissolved lead concentrations, indicating that dissolved lead probably occurs fully complexed in these lakes. Therefore the toxic fraction is likely to be less than the dissolved lead concentration. Also, lead concentrations at the time of the spring thaw are higher than autumn concentrations just before ice cover, indicating that a significant proportion of fallout onto the lake catchment

  1. Lead shot poisoning of a Pacific loon in Alaska

    Science.gov (United States)

    Wilson, H.M.; Oyen, J.L.; Sileo, L.

    2004-01-01

    Lead poisoning, associated with ingestion of spent lead shot, was diagnosed in an adult female Pacific loon (Gavia pacifica) observed with partial paralysis on 13 June 2002 and found dead on 16 June 2002 on Kigigak Island, Yukon Delta National Wildlife Refuge, western Alaska, USA. A necropsy revealed three pellets of ingested lead shot in the loona??s gizzard and a lead liver concentration of 31 ppm wet weight, which was consistent with metallic lead poisoning. This is the first report of lead poisoning in a Pacific loon and is the only account of lead toxicosis associated with ingestion of lead shot in any loon species breeding in Alaska.

  2. Effect of subclinical lead intake on calves

    Energy Technology Data Exchange (ETDEWEB)

    Dinius, D.A.; Brinsfield, T.H.; Williams, E.E.

    1973-01-01

    Sixteen bull calves were fed a 70% concentrate diet containing no added lead, 10 ppM lead from newsprint, or 10 and 100 ppM lead from lead chromate. The diets were pelleted and fed ad libitum for 100 days. Fecal and urine samples were collected and EKG and respiration rates were monitored at 25-day intervals. At the end of the 100-day feeding trial, the calves were sacrificed and samples of skeletal muscle, cerebral cortex, liver and kidney were collected for lead analysis. Supplemental lead did not affect feed consumption nor weight gain; however, newsprint depressed both intake and gain. Neither EKG patterns, heart rate nor respiration rate were affected by dietary treatment. The percentage of ingested lead excreted in feces and urine was not significantly different among treatments. There were no significant tissue accumulations of lead from feeding newsprint or 10 ppM lead chromate; however, feeding 100 ppM lead chromate resulted in accumulations of the element in liver and kidney. Samples of cerebral cortex, liver and kidney cortex were examined by electron microscopy. Changes were not detected in the cellular ultrastructure of these tissues from either control or treated animals.

  3. Relational Perspectives on Leading

    DEFF Research Database (Denmark)

    Larsen, Mette Vinther; Rasmussen, Jørgen Gulddahl

    2015-01-01

    Relational Perspectives on Leading discusses leadership from a relational and social constructionism perspective as practiced on an everyday basis between people. The book pursues a fast growing, practice-based approach - particularly within the Anglo-Saxon parts of the world - to organization...... studies and organizational phenomena....

  4. lead glass brick

    CERN Multimedia

    As well as accelerators to boost particles up to high energy, physicists need detectors to see what happens when those particles collide. This lead glass block is part of a CERN detector called OPAL. OPAL uses some 12 000 blocks of glass like this to measure particle energies.

  5. Girls Leading Outward

    Science.gov (United States)

    Hamed, Heather; Reyes, Jazmin; Moceri, Dominic C.; Morana, Laura; Elias, Maurice J.

    2011-01-01

    The authors describe a program implemented in Red Bank Middle School in New Jersey to help at-risk, minority middle school girls realize their leadership potential. The GLO (Girls Leading Outward) program was developed by the Developing Safe and Civil Schools Project at Rutgers University and is facilitated by university students. Selected middle…

  6. Leading by Learning

    Science.gov (United States)

    Brookhart, Susan M.; Moss, Connie M.

    2013-01-01

    A lot has changed in the principalship since the principal was the head teacher in a school. Current principals are building administrators and that is likely to continue, the authors posit. Nonetheless, they report their study focusing on leadership's role in formative assessment concluded that in order to lead learning the principal must become…

  7. Change, Lead, Succeed

    Science.gov (United States)

    Munger, Linda; von Frank, Valerie

    2010-01-01

    Redefine leadership in your school, and create capacity through school leadership teams that successfully coordinate professional learning. "Change, Lead, Succeed" shows school leaders and teachers in leadership roles what they need to know to effectively create a culture for change. Find out what distinguishes a school leadership team from other…

  8. Lead level in seminal plasma may affect semen quality for men without occupational exposure to lead

    Directory of Open Access Journals (Sweden)

    Wu Hsien-Ming

    2012-11-01

    Full Text Available Abstract Background Infertility affects approximately 10–15% of reproductive-age couples. Poor semen quality contributes to about 25% of infertile cases. Resulting from the direct effect on testicular function or hormonal alterations, heavy metals exposure has been related to impaired semen quality. The objective of this study was to assess the level of lead in the seminal plasma in men without occupational exposure to lead, and to determine the relationship between semen quality and lead concentration in the semen. Methods This is a prospective and nonrandomized clinical study conducted in University infertility clinic and academic research laboratory. Three hundred and forty-one male partners of infertile couples undergoing infertility evaluation and management were recruited to the study. Semen samples collected for the analyses of semen quality were also used for the measurement of lead concentrations. Semen samples were evaluated according to the WHO standards. Results All subjects were married and from infertile couples without occupational exposure to lead. There is a significant inverse correlation between the lead concentration in seminal plasma and sperm count. A higher semen lead concentration was correlated with lower sperm count, but not with semen volume, sperm motility or sperm morphology as assessed by simple linear regression. Conclusions We found that semen lead concentration was significantly higher among the patients with lower sperm count. To our knowledge, this is the first study to demonstrate that a high level of lead accumulation in semen may reduce the sperm count contributing to infertility of men without occupational exposure to lead.

  9. Lead Isotopes in Highway Runoff

    Science.gov (United States)

    Ferreira, M.; Lau, S.; Green, P. G.; Stenstrom, M. K.

    2011-12-01

    Lead (Pb) isotopes have been used extensively to study the provenance of lead pollution on air, water, and sediments. In this study, we measured Pb isotopes and Pb aqueous concentration in highway runoff in three west Los Angeles sites. Those three sites, part of a long-term study sponsored by the California Department of Transportation, represent small catchment areas, and host heavy traffic. In addition, there were no inputs of sand or salt to the highway because the sites are almost completely impervious and also due to the lack of snow to be controlled. Highway runoff from the three sites was collected for 7 storms during the 2004-2005 Winter. Grab samples were collected every 15 minutes during the first hour, and hourly afterwards. A total of 202 samples were collected and filtered into five size fractions (100μm). Aqueous concentration of Pb range from 0.08μg/L to 46.95μg/L (7.98±10.89μg/L) and it is not correlated with any of the lead isotope ratios. The 208Pb/206Pb ratio ranges from 1.983 to 2.075 (2.024±0.026) and there is no statistical difference for the mean value of the 208Pb/206Pb ratio for the four particulate size fractions (0.45-8μm, 8-20μm, 20-100μm, >100μm). However, the 208Pb/206Pb ratio of nearby soils yield 2.060±0.021 and it is statistically different from the ratios obtained for the highway runoff. This hints that the lead present in highway runoff does not come from local soils. The 207Pb/206Pb ratio ranges from 0.804 to 0.847 (0.827±0.011) and there is no statistical difference for the mean value of the 207Pb/206Pb ratio for the four particulate size fractions (0.45-8μm, 8-20μm, 20-100μm, >100μm). Surprisingly, there is also no statistical difference with the 207Pb/206Pb ratio of nearby soils (0.833±0.009).

  10. Heavy-metal concentrations in three owl species from Korea.

    Science.gov (United States)

    Kim, Jungsoo; Lee, Hang; Koo, Tae-Hoe

    2008-01-01

    This study presents concentrations of heavy metals (iron, zinc, manganese, copper, lead, and cadmium) in livers of three owl species from Korea. Essential trace elements (iron, zinc, manganese, and copper) did not differ among the owl species. We suggest that the essential elements are within the normal range and are maintained by normal homeostatic mechanisms. Lead and cadmium concentrations in Eurasian Eagle Owls (Bubo bubo) were significantly lower than in Brown Hawk Owls (Nixos scutulata) and Collared Scops Owls (Otus lempiji). Lead and cadmium concentrations in Korean owl species were at background levels; lead concentrations in two Collared Scops Owls were above background concentrations. Lead and cadmium concentrations were similar to concentrations previously reported in owls from other parts of the world. We suggest that lead and cadmium concentrations in Korean owls are below toxic concentrations.

  11. Lead identification in soil surrounding a used lead acid battery smelter area in Banten, Indonesia

    Science.gov (United States)

    Adventini, N.; Santoso, M.; Lestiani, D. D.; Syahfitri, W. Y. N.; Rixson, L.

    2017-06-01

    A used lead acid battery smelter generates particulates containing lead that can contaminate the surrounding environment area. Lead is a heavy metal which is harmful to health if it enters the human body through soil, air, or water. An identification of lead in soil samples surrounding formal and informal used lead acid battery smelters area in Banten, Indonesia using EDXRF has been carried out. The EDXRF accuracy and precision evaluated from marine sediment IAEA 457 gave a good agreement to the certified value. A number of 16 soil samples from formal and informal areas and 2 soil samples from control area were taken from surface and subsurface soils. The highest lead concentrations from both lead smelter were approximately 9 folds and 11 folds higher than the reference and control samples. The assessment of lead contamination in soils described in Cf index was in category: moderately and strongly polluted by lead for formal and informal lead smelter. Daily lead intake of children in this study from all sites had exceeded the recommended dietary allowance. The HI values for adults and children living near both lead smelter areas were greater than the value of safety threshold 1. This study finding confirmed that there is a potential health risk for inhabitants surrounding the used lead acid battery smelter areas in Banten, Indonesia.

  12. CMS lead tungstate crystals

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    These crystals are made from lead tungstate, a crystal that is as clear as glass yet with nearly four times the density. They have been produced in Russia to be used as scintillators in the electromagnetic calorimeter on the CMS experiment, part of the LHC project at CERN. When an electron, positron or photon passes through the calorimeter it will cause a cascade of particles that will then be absorbed by these scintillating crystals, allowing the particle's energy to be measured.

  13. Leading Generation Y

    Science.gov (United States)

    2008-04-01

    ensure the success of their child, failure is not often experienced. These successes and the ease of childhood lead to not only confidence but an...Messaging, chatting on the cell phone and working on homework is a common place scene for teens and college students. “The level of multiprocessing...to Gen Yers entering the workforce with unrealistic expectations and a sense of entitlement. Barbara Dwyer, CEO of the Job Journey, states that

  14. Superconductivity of lead

    Energy Technology Data Exchange (ETDEWEB)

    Boorse, H.A.; Cook, D.B.; Zemansky, W.M.

    1950-06-01

    Numerous determinations of the zero-field transition temperature of lead have been made. All of these observations except that of Daunt were made by the direct measurement of electrical resistance. Daunt`s method involved the shielding effect of persistent currents in a hollow cylinder. In the authors work on columbium to be described in a forthcoming paper an a.c. induction method was used for the measurement of superconducting transitions. The superconductor was mounted as a cylindrical core of a coil which functioned as the secondary of a mutual inductance. The primary coil was actuated by an oscillator which provided a maximum a.c. field within the secondary of 1.5 oersteds at a frequency of 1000 cycles per second. The secondary e.m.f. which was dependent for its magnitude on the permeability of the core was amplified, rectifie, and observed on a recording potentiometer. During the application of this method to the study of columbium it appeared that a further check on the zero-field transition temperature of lead would be worth while especially if agreement between results for very pure samples could be obtained using this method. Such result would help in establishing the lead transition temperature as a reasonably reproducible reference point in the region between 4 deg and 10 deg K.

  15. Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary

    Science.gov (United States)

    Ritson, P.I.; Bouse, R.M.; Flegal, A.R.; Luoma, S.N.

    1999-01-01

    Variations in stable lead isotopic composition (240Pb, 206Pb, 207Pb, 208Pb) in three sediment cores from the San Francisco Bay estuary document temporal changes in sources of lead during the past two centuries. Sediment, with lead from natural geologic sources, and relatively homogeneous lead isotopic compositions are overlain by sediments whose isotopic compositions indicate change in the sources of lead associated with anthropogenic modification of the estuary. The first perturbations of lead isotopic composition in the cores occur in the late 1800s concordant with the beginning of industrialization around the estuary. Large isotopic shifts, toward lower 206Pb/207Pb, occur after the turn of the century in both Richardson and San Pablo Bays. A similar relationship among lead isotopic compositions and lead concentrations in both Bays suggest contamination from the same source (a lead smelter). The uppermost sediments (post 1980) of all cores also have a relatively homogenous lead isotopic composition distinct from pre-anthropogenic and recent aerosol signatures. Lead isotopic compositions of leachates from fourteen surface sediments and five marsh samples from the estuary were also analyzed. These analyses suggest that the lead isotopic signature identified in the upper horizons of the cores is spatially homogeneous among recently deposited sediments throughout the estuary. Current aerosol lead isotopic compositions [Smith, D.R., Niemeyer, S., Flegal, A.R., 1992. Lead sources to California sea otters: industrial inputs circumvent natural lead biodepletion mechanisms. Environmental Research 57, 163-175] are distinct from the isotopic compositions of the surface sediments, suggesting that the major source of lead is cycling of historically contaminated sediments back through the water column. Both the upper core sediments and surface sediments apparently derive their lead predominantly from sources internal to the estuary. These results support the idea that

  16. Childhood lead exposure and uptake in teeth in the Cleveland area during the era of leaded gasoline

    Energy Technology Data Exchange (ETDEWEB)

    Robbins, Norman, E-mail: nxr@case.edu [Department of Neurosciences (Emeritus), Case Western Reserve University, Cleveland, Ohio, 44106-4975 (United States); Zhang, Zhong-Fa, E-mail: zzhang@wistar.org [Center for Systems and Computational Biology, The Wistar Institute, Philadelphia, Pennsylvania, 19104 (United States); Sun, Jiayang, E-mail: jiayang@sun.cwru.edu [Center for Systems and Computational Biology, The Wistar Institute, Philadelphia, Pennsylvania, 19104 (United States); Ketterer, Michael E., E-mail: Michael.Ketterer@nau.edu [Department of Chemistry and Biochemistry, Northern Arizona University, Box 5698, Flagstaff, Arizona, 86011-5698 (United States); Lalumandier, James A., E-mail: James.lalumandier@case.edu [School of Dental Medicine, Case Western Reserve University, Cleveland, Ohio, 44106-4905 (United States); Shulze, Richard A., E-mail: carbonvalleydental@gmail.com [School of Dental Medicine, Case Western Reserve University, Cleveland, Ohio, 44106-4905 (United States)

    2010-09-01

    Childhood uptake of lead from exposure to atmospheric leaded gasoline in the United States has been studied using mainly blood lead levels. Since reliable blood lead techniques were used only after the peak use of leaded gasoline, the prior exposure history is unclear. The well-documented decline in blood lead levels after the mid-1970s could represent the continuation of a historic steady decline in exposure from many sources. Alternatively, the post-1970s decline might represent the declining phase of a unimodal rise and fall corresponding closely to usage of leaded gasoline. To assess these possibilities, lead concentration and 207Pb/206Pb isotope ratios were measured in the enamel of permanent molar teeth formed between 1936 and 1993 in mainly African-American donors who grew up in the Cleveland area. Tooth enamel preserves the lead concentration and isotope ratio that prevails during tooth formation. Historical trends in enamel lead concentration were significantly correlated with surrogates of atmospheric lead exposure: lead in sediments of two dated Lake Erie cores, and lead consumed in gasoline. About two-thirds of the total lead uptake into enamel in this period was attributable to leaded gasoline, and the remainder to other sources (e.g. paint). Enamel 207Pb/206Pb isotope ratios were similar to those of one lake sediment. Multivariate analysis revealed significant correlation in neighborhoods with higher levels of traffic, and including lake sediment data, accounted for 53% of the variation in enamel lead levels. Enamel lead concentration was highly correlated with reported African-American childhood blood levels. The extrapolated peak level of 48 {mu}g/dL (range 40 to 63) is associated with clinical and behavioral impairments, which may have implications for adults who were children during the peak gasoline lead exposure. In sum, leaded gasoline emission was the predominant source of lead exposure of African-American Cleveland children during the latter

  17. Scattering Solar Thermal Concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Giebink, Noel C. [Pennsylvania State Univ., State College, PA (United States)

    2015-01-31

    concentrator optical efficiency was found to decrease significantly with increasing aperture width beyond 0.5 m due to parasitic waveguide out-coupling loss and low-level absorption that become dominant at larger scale. A heat transfer model was subsequently implemented to predict collector fluid heat gain and outlet temperature as a function of flow rate using the optical model as a flux input. It was found that the aperture width size limitation imposed by the optical efficiency characteristics of the waveguide limits the absolute optical power delivered to the heat transfer element per unit length. As compared to state-of-the-art parabolic trough CPV system aperture widths approaching 5 m, this limitation leads to an approximate factor of order of magnitude increase in heat transfer tube length to achieve the same heat transfer fluid outlet temperature. The conclusion of this work is that scattering solar thermal concentration cannot be implemented at the scale and efficiency required to compete with the performance of current parabolic trough CSP systems. Applied within the alternate context of CPV, however, the results of this work have likely opened up a transformative new path that enables quasi-static, high efficiency CPV to be implemented on rooftops in the form factor of traditional fixed-panel photovoltaics.

  18. Bioremediation potential of spirulina: toxicity and biosorption studies of lead

    OpenAIRE

    Chen, Hong; Pan, Shan-shan

    2005-01-01

    This study examines the possibility of using live spirulina to biologically remove aqueous lead of low concentration (below 50 mg/L) from wastewater. The spirulina cells were first immersed for seven days in five wastewater samples containing lead of different concentrations, and the growth rate was determined by light at wavelength of 560 nm. The 72 h-EC50 (72 h medium effective concentration) was estimated to be 11.46 mg/L (lead). Afterwards, the lead adsorption by live spirulina cells was ...

  19. Altering prolactin concentrations in sows.

    Science.gov (United States)

    Farmer, C

    2016-07-01

    Prolactin has a multiplicity of actions, but it is of particular importance in gestating and lactating animals. In sows, it is involved in the control of mammary development and also holds essential roles in the lactogenic and galactopoietic processes. Furthermore, low circulating concentrations of prolactin are associated with the agalactia syndrome. The crucial role of prolactin makes it important to understand the various factors that can alter its secretion. Regulation of prolactin secretion is largely under the negative control of dopamine, and dopamine agonists consistently decrease prolactin concentrations in sows. On the other hand, injections of dopamine antagonists can enhance circulating prolactin concentrations. Besides pharmacologic agents, many other factors can also alter prolactin concentrations in sows. The use of Chinese-derived breeds, for instance, leads to increased prolactin concentrations in lactating sows compared with standard European white breeds. Numerous husbandry and feeding practices also have a potential impact on prolactin concentrations in sows. Factors, such as provision of nest-building material prepartum, housing at farrowing, high ambient temperature, stress, transient weaning, exogenous thyrotropin-releasing factor, exogenous growth hormone-releasing factor, nursing frequency, prolonged photoperiod, fasting, increased protein and/or energy intake, altered energy sources, feeding high-fiber diets, sorghum ergot or plant extracts, were all studied with respect to their prolactinemic properties. Although some of these practices do indeed affect circulating prolactin concentrations, none leads to changes as drastic as those brought about by dopamine agonists or antagonists. It appears that the numerous factors regulating prolactin concentrations in sows are still not fully elucidated, and that studies to develop novel applicable ways of increasing prolactin concentrations in sows are warranted. Crown Copyright © 2015. Published

  20. New inovation and improvments in lead and conc. For selective flotation for lead-zink mine Sasa

    OpenAIRE

    2011-01-01

    New improvement in technological process from collective to selective lead and zinc flotation, renewed recent and advanced equipments, new flotation flowsheet with increased recovery and quality in lead and zinc concentrates. Many advantages in other sections of the concentrator, better financial results with appropriate environmental approaches eith ensured conditions in tailing dam, improvement in refused mine water in the surrounding river.

  1. Optimization leads to symmetry

    Institute of Scientific and Technical Information of China (English)

    Chenghong WANG; Yuqian GUO; Daizhan CHENG

    2004-01-01

    The science of complexity studies the behavior and properties of complex systems in nature and human society.Particular interest has been put on their certain simple common properties.Symmetry is one of such properties.Symmetric phenomena can be found in many complex systems.The purpose of this paper is to reveal the internal reason of the symmetry.Using some physical systems and geometric objects,the paper shows that many symmetries are caused by optimization under certain criteria.It has also been revealed that an evolutional process may lead to symmetry.

  2. Leading change: 2--planning.

    Science.gov (United States)

    Kerridge, Joanna

    National initiatives have outlined the importance of involving frontline staff in service improvement, and the ability to influence and manage change has been identified as an essential skill for delivering new models of care. Nurses often have to take the lead in managing change in clinical practice. The second in a three-part series is designed to help nurses at all levels develop the knowledge and skills to function as change agents within their organisations. This article focuses on planning the change and dealing with resistance.

  3. lead glass brick

    CERN Multimedia

    When you look through the glass at a picture behind, the picture appears raised up because light is slowed down in the dense glass. It is this density (4.06 gcm-3) that makes lead glass attractive to physicists. The refractive index of the glass is 1.708 at 400nm (violet light), meaning that light travels in the glass at about 58% its normal speed. At CERN, the OPAL detector uses some 12000 blocks of glass like this to measure particle energies.

  4. Turning lead into gold

    DEFF Research Database (Denmark)

    Jensen, Steffen Moltrup Ernø

    For years the field of entrepreneurship has been blinded by the alchemical promise of turning lead into gold, of finding the ones most likely to become the next Branson, Zuckerberg or Gates. The promise has been created in the midst of political and scientific agendas where certain individuals...... is not to accumulate state or market wealth, but for entrepreneurial skills to become tools towards the liberation of the individual from oppressive systems of control – essentially to add public value rather than economic value. In this presentation I will sketch an anarchist perspective on entrepreneurship, looking...

  5. The effect of lead on Allium cepa L.

    Science.gov (United States)

    Lerda, D

    1992-02-01

    The effect of lead on Allium cepa L. at concentrations of 0.1, 1.0, 10, 50, 100 and 200 ppm were studied. Analysis focused on root growth, frequency of mitosis in a meristematic zone, and chromosomal aberrations. It was observed that lead reduces root growth and the frequency of mitotic cells in meristematic zones, and increases the frequency of aberrant cells. The intensity of the effects is a function of lead concentration.

  6. Lead exposure in Canada geese of the Eastern Prairie Population

    Science.gov (United States)

    DeStefano, S.; Brand, C.J.; Rusch, D.H.; Finley, Daniel L.; Gillespie, M.M.

    1991-01-01

    We monitored lead exposure in Eastern Prairie Population Canada geese during summer-winter, 1986-1987 and 1987-1988 at 5 areas. Blood lead concentrations in geese trapped during summer at Cape Churchill Manitoba were below levels indicative of recent lead exposure (0.18 ppm). Geese exposed to lead (≥0.18 ppm blood lead) increased to 7.6% at Oak Hammock Wildlife Management Area (WMA), southern Manitoba, where lead shot was still in use, and to 10.0% at Roseau River WMA, northern Minnesota, when fall-staging geese were close to a source of lead shot in Manitoba. Proportion of birds exposed to lead dropped to <2% at Lac Qui Parle WMA, Minnesota, a steel shot zone since 1980. On the wintering grounds at Swan Lake National Wildlife Refuge in Missouri, 4.9% of all geese showed exposure to lead before the hunting season. Lead exposure rose to 10.0% after hunting ended and then decreased to 5.2% in late winter. Incidence of lead shot in gizzards and concentrations of lead in livers supported blood assay data. Soil samples indicated that lead shot continues to be available to geese at Swan Lake, even though the area was established as a non-toxic shot zone in 1978. Steel shot zones have reduced lead exposure in the Eastern Prairie Population, but lead shot persists in the environment and continues to account for lead exposure and mortality in Eastern Prairie Population Canada geese.

  7. Effects of lead-contaminated sediment on Rana sphenocephala tadpoles

    Science.gov (United States)

    Sparling, D.W.; Krest, S.K.; Ortiz-Santaliestra, M.

    2006-01-01

    We exposed larval southern leopard frogs (Rana sphenocephala) to lead-contaminated sediments to determine the lethal and sublethal effects of this metal. Tadpoles were laboratory-raised from early free-swimming stage through metamorphosis at lead concentrations of 45, 75, 180, 540, 2360, 3940, 5520, and 7580 mg/kg dry weight in sediment. Corresponding pore water lead concentrations were 123, 227, 589, 1833, 8121, 13,579, 19,038, and 24,427 ug/L. Tadpoles exposed to lead concentrations in sediment of 3940 mg/kg or higher died within 2 to 5 days of exposure. At lower concentrations, mortality through metamorphosis ranged from 3.5% at 45 mg/kg lead to 37% at 2360 mg/kg lead in sediment. The LC50 value for lead in sediment was 3728 mg/kg (95% CI=1315 to 72,847 mg/kg), which corresponded to 12,539 ug/L lead in pore water (95% CI= 4000 to 35,200 ug/L). Early growth and development were depressed at 2,360 mg/kg lead in sediment (8100 ug/L in pore water) but differences were not evident by the time of metamorphosis. The most obvious effect of lead was its pronounced influence on skeletal development. Whereas tadpoles at 45 mg/kg lead in sediment did not display permanent abnormalities, skeletal malformations increased in frequency and severity at all higher lead concentrations. By 2360 mg/kg, 100% of surviving metamorphs displayed severe spinal problems, reduced femur and humerus lengths, deformed digits, and other bone malformations. Lead concentrations in tissues correlated positively with sediment and pore water concentrations.

  8. [Reasons for the changes in anthropogenic lead flows of China].

    Science.gov (United States)

    Ma, Lan; Mao, Jian-Su

    2014-08-01

    In recent years, accompanied by a series of comprehensive improvement actions on lead pollution, anthropogenic lead flows of China have somewhat changed; by exploring the reasons, some references can be provided for further improvement in resource utilization and environment quality. In this paper, based on the framework of lead flow analysis, the causes of changes in lead flows were identified and divided into scale factors and technical factors. Based on that and taking indices such as the quantities of lead production and recovered lead scraps, and lead recycling rate and emission rates as the scale and technical indices, respectively, the reasons for the changes of lead flow in our country were analyzed from the aspects of consumption, trade, technology, management and so on. The results showed: the domestic consumption of lead products has been gro wing quickly at an average annual rate of 24.7%, which pulled the growth of domestic lead consumption; The growth of lead consumption further increased the growth of lead production at an average annual rate of 14.2%, which finally pulled the growth of domestic lead ore resource consumption, lead concentrates net imports and lead scraps recovering; The increases in domestic consumption ratio of final lead products promoted the improvement of the lead recycling rate; As national management was strengthened, most lead-enterprises with small scale and old-dated technologies were closed, meanwhile, some advanced technologies were encouraged to be employed, thus the general resource utilization rate was improved and environmental lead emissions rate was reduced.

  9. The leaching of lead from lead-based paint in landfill environments.

    Science.gov (United States)

    Wadanambi, Lakmini; Dubey, Brajesh; Townsend, Timothy

    2008-08-30

    Lead leaching from lead-based paint (LBP) was examined using standardized laboratory protocols and tests with leachate from actual and simulated landfill environments. Two different LBP samples were tested; leaching solutions included leachates from three municipal solid waste (MSW) landfills and three construction and demolition (C&D) debris landfills. The toxicity characteristic leaching procedure (TCLP) and the synthetic precipitation leaching procedure (SPLP) were also performed. Lead concentrations were many times higher using the TCLP compared to the SPLP and the landfill leachates. No significant difference (alpha=0.05) was observed in leached lead concentrations from the MSW landfill and C&D debris landfill leachates. The impact of other building materials present in LBP debris on lead leaching was examined by testing mixtures of LBP (2%) and different building materials (98%; steel, wood, drywall, concrete). The type of substrate present impacted lead leaching results, with concrete demonstrating the most dramatic impact; the lowest lead concentrations were measured in the presence of concrete under both TCLP and SPLP extractions.

  10. Lead in Drinking Water in Slovenian Kindergartens and Schools

    Directory of Open Access Journals (Sweden)

    Bitenc K.

    2013-04-01

    Full Text Available The purpose of the work is to determine how high are the concentrations of lead in drinking water in older Slovenian kindergartens and primary schools and to demonstrate that lead can also migrate from newer materials used for the construction of water distribution networks. To determine the concentrations of lead in drinking water, it is needed to take 250 ml of drinking water that stood in the pipes from 8 to 18hours. It is also applied a method for determining the migration from different materials. An old lead pipe is utilized, as well as new materials (PEX-Al-PEX, copper, galvanized pipes and stainless steel pipes. Sampling showed that 6 samples of 39 had levels of lead higher than 10 µg/l, two of them highly exceeded that level. Negative correlation between the level of pH and concentration of lead in drinking water is moderate. Implementation of lead migration from various types of pipes demonstrated the migration from galvanized pipes in all simulants. Furthermore, the migration of lead from galvanized pipes is dependent on water temperature. The migration was confirmed from the lead pipe as expected. Study points to a problem with elevated concentrations of lead in drinking water faced by older kindergartens and primary schools in Slovenia. All concentrations of lead after flushing the pipes were below the 10 µg/l, which shows that the most effective action to lower the concentrations of lead is flushing the water pipes. For the purposes of national monitoring of drinking water is necessary to apply a better method for determining lead levels in drinking water namely the sampling of water that stood in the pipes at least 8 to 18 hours. This study has demonstrated the migration of lead from galvanized pipes. This material is also installed in 54 % of kindergartens and primary schools that participated in the study.

  11. Lead distribution in the saliva and blood fractions of rats after intraperitoneal injections.

    Science.gov (United States)

    Mobarak, N; P'an, A Y

    1984-07-01

    Sprague-Dawley rats were treated with 1, 2 or 3 i.p. injections of lead acetate (100 mg/kg) and sacrificed 24 h, 3 days, 7 days, 14 days and 21 days after the last injection. Lead concentration was determined by flameless AAS technique in whole blood, plasma, plasma filtrate, saliva and submaxillary gland tissue. The concentration of lead in saliva was about 5% of whole blood lead concentration and around 61% of plasma filtrate lead level. Saliva lead concentration was significantly related both to whole blood lead concentration and plasma filtrate lead concentration (r = 0.78, P less than 0.001; r = 0.80, P = 0.001 respectively). Lead was present in the submaxillary gland tissue; the amount of lead increased with increasing amounts administered.

  12. Cofilin takes the lead.

    Science.gov (United States)

    DesMarais, Vera; Ghosh, Mousumi; Eddy, Robert; Condeelis, John

    2005-01-01

    Cofilin has emerged as a key regulator of actin dynamics at the leading edge of motile cells. Through its actin-severing activity, it creates new actin barbed ends for polymerization and also depolymerizes old actin filaments. Its function is tightly regulated in the cell. Spatially, its activity is restricted by other actin-binding proteins, such as tropomyosin, which compete for accessibility of actin filament populations in different regions of the cell. At the molecular level, it is regulated by phosphorylation, pH and phosphatidylinositol (4,5)-bisphosphate binding downstream of signaling cascades. In addition, it also appears to be regulated by interactions with 14-3-3zeta and cyclase-associated protein. In vivo, cofilin acts synergistically with the Arp2/3 complex to amplify local actin polymerization responses upon cell stimulation, which gives it a central role in setting the direction of motility in crawling cells.

  13. Lead telluride alloy thermoelectrics

    Directory of Open Access Journals (Sweden)

    Aaron D. LaLonde

    2011-11-01

    Full Text Available The opportunity to use solid-state thermoelectrics for waste heat recovery has reinvigorated the field of thermoelectrics in tackling the challenges of energy sustainability. While thermoelectric generators have decades of proven reliability in space, from the 1960s to the present, terrestrial uses have so far been limited to niche applications on Earth because of a relatively low material efficiency. Lead telluride alloys were some of the first materials investigated and commercialized for generators but their full potential for thermoelectrics has only recently been revealed to be far greater than commonly believed. By reviewing some of the past and present successes of PbTe as a thermoelectric material we identify the issues for achieving maximum performance and successful band structure engineering strategies for further improvements that can be applied to other thermoelectric materials systems.

  14. Leading from the boardroom.

    Science.gov (United States)

    Lorsch, Jay W; Clark, Robert C

    2008-04-01

    These days, boards are working overtime to comply with Sarbanes-Oxley and other governance requirements meant to protect shareholders from executive wrongdoing. But as directors have become more hands-on with compliance, they've become more hands-off with long-range planning. That exposes corporations and their shareholders to another--perhaps even greater--risk, say professors Lorsch, of Harvard Business School, and Clark, of Harvard Law School. Boards are giving the long term short shrift for a number of reasons. Despite much heavier workloads, directors haven't rethought their patterns of operating - their meetings, committees, and other interactions. Compliance has changed their relationship with executives, however, turning directors into micromanagers who closely probe executives' actions instead of providing high-level guidance. Meanwhile, the pressure to meet quarterly expectations intensifies. Directors need to do a better job of balancing compliance with forward thinking. Boardroom effectiveness hinges most on the quality of directors and their interactions, the authors' research shows. Directors must apply their wisdom broadly, handling compliance work more efficiently and staying out of the weeds on strategic issues. Using their power with management to evangelize for long-term planning, they must take the lead on discussions about financial infrastructure, talent development, and strategy. Reserving sacrosanct time for such discussions, as Philips Electronics' board does at annual retreats, is an effective practice: After one recent retreat, Philips decided to exit the semiconductor business, where it was losing ground. Individual directors also must not shy away from asking tough questions and acting as catalysts on critical issues, such as grooming a successor to the CEO. In short, directors must learn to lead from the boardroom.

  15. Costs of IQ Loss from Leaded Aviation Gasoline Emissions.

    Science.gov (United States)

    Wolfe, Philip J; Giang, Amanda; Ashok, Akshay; Selin, Noelle E; Barrett, Steven R H

    2016-09-06

    In the United States, general aviation piston-driven aircraft are now the largest source of lead emitted to the atmosphere. Elevated lead concentrations impair children's IQ and can lead to lower earnings potentials. This study is the first assessment of the nationwide annual costs of IQ losses from aircraft lead emissions. We develop a general aviation emissions inventory for the continental United States and model its impact on atmospheric concentrations using the community multi-scale air quality model (CMAQ). We use these concentrations to quantify the impacts of annual aviation lead emissions on the U.S. population using two methods: through static estimates of cohort-wide IQ deficits and through dynamic economy-wide effects using a computational general equilibrium model. We also examine the sensitivity of these damage estimates to different background lead concentrations, showing the impact of lead controls and regulations on marginal costs. We find that aircraft-attributable lead contributes to $1.06 billion 2006 USD ($0.01-$11.6) in annual damages from lifetime earnings reductions, and that dynamic economy-wide methods result in damage estimates that are 54% larger. Because the marginal costs of lead are dependent on background concentration, the costs of piston-driven aircraft lead emissions are expected to increase over time as regulations on other emissions sources are tightened.

  16. Lead poisoning in six captive avian species

    Science.gov (United States)

    Beyer, W.N.; Spann, J.W.; Sileo, L.; Franson, J.C.

    1988-01-01

    Red-winged blackbirds (Agelaius phoeniceus), brown-headed cowbirds (Molothrus ater), common grackles (Quiscalus quiscula), mallards (Anas platyrhynchos), northern bobwhites (Colinus virginianus), and eastern screech-owls (Otus asio) were poisoned with a concentration of lead (Pb) acetate in the diet which was increased by 60% each week until half of the birds in each treatment group died; surviving birds and all control birds except screech-owls were then killed by euthanasia. An additional group of mallards was poisoned with Pb shot. The gizzards of mallards poisoned either way usually were stained with bile; some of these birds also had proventricular impaction. Most poisoned birds of the other species were emaciated but lacked other gross lesions caused by Pb poisoning. In birds other than mallards, Pb poisoning could not be diagnosed without histological or hematological examinations or analysis of tissues. Poisoned birds of all six species could be reliably separated from control birds by an increase in the protoporphyrin concentrations in the blood and by a decrease in the activity of delta-aminoievulinic acid dehydratase (ALAD) in red blood cells. Hepatic iron (Fe) concentrations varied so much among individual birds that even though median hepatic Fe concentrations increased in poisoned birds, hepatic Fe concentrations were not useful in identifying poisoned birds. Renal intranuclear inclusion bodies occurred in 83% of all birds dying from Pb poisoning. Nephrosis, myocardial necrosis, and arterial fibrinoid necrosis were occasionally present. Median hepatic Pb concentrations varied from 20 ppm (wet wt) in male red-winged blackbirds to III ppm in female northern bobwhites. Median renal Pb concentrations varied from 22 ppm in red-winged blackbirds to 190 ppm in female northern bobwhites. Hepatic and renal Pb concentrations varied substantially among birds within each species. Median hepatic and renal Pb concentrations of birds that died were not statistically

  17. Site-specific lead exposure from lead pellet ingestion in sentinel mallards

    Science.gov (United States)

    Rocke, T.E.; Brand, C.J.; Mensik, John G.

    1997-01-01

    We monitored lead poisoning from the ingestion of spent lead pellets in sentinel mallards (Anas platyhrynchos) at the Sacramento National Wildlife Refuge (SNWR), Willows, California for 4 years (1986-89) after the conversion to steel shot for waterfowl hunting on refuges in 1986. Sentinel mallards were held in 1.6-ha enclosures in 1 hunted (P8) and 2 non-hunted (T19 and TF) wetlands. We compared site-specific rates of lead exposure, as determined by periodic measurement of blood lead concentrations, and lead poisoning mortality between wetlands with different lead pellet densities, between seasons, and between male and female sentinels. In 1986, the estimated 2-week rate of lead exposure was significantly higher (P 2,000,000 pellets/ha), than in those with lower densities of lead pellets, T19 (18.1%; 173,200 pellets/ha) and TF (0.9%; 15,750 pellets/ha). The probability of mortality from lead poisoning was also significantly higher (P < 0.01) in sentinel mallards enclosed in P8 (0.25) than T19 (0) and TF (0) in 1986 and remained significantly higher (P < 0.001) during the 4-year study. Both lead exposure and the probability of lead poisoning mortality in P8 were significantly higher (P < 0.001) in the fall of 1986 (43.8%; 0.25), before hunting season, than in the spring of 1987 (21.6%; 0.04), after hunting season. We found no significant differences in the rates of lead exposure or lead poisoning mortality between male and female sentinel mallards. The results of this study demonstrate that in some locations, lead exposure and lead poisoning in waterfowl will continue to occur despite the conversion to steel shot for waterfowl hunting.

  18. Engine reconditioning workshops: lead contamination and the potential risk for workers: a pilot study

    OpenAIRE

    James, M G; Gulson, B L

    1999-01-01

    Lead concentrations were measured in surface dust, airborne dust, air, and grinding material from five engine reconditioning workshops to evaluate the impact on blood lead concentrations (PbB) of 10 employees. Lead in the environmental samples ranged from trace amounts to extremely high concentrations (4667 mg/m2). The highest concentrations in surface wipes were found in areas where engine deposits are removed from valves and valve seats. The amounts of lead in long term dustfall accum...

  19. Environmental lead exposure increases micronuclei in children

    DEFF Research Database (Denmark)

    Kapka, Lucyna; Baumgartner, Adolf; Siwińska, Ewa

    2007-01-01

    The objective of this pilot study was to investigate the contribution of environmental exposures to lead in the development of cytogenetic damage detected as the frequency of micronuclei (MN) in children. The other aim was to apply the MN assay in combination with fluorescence in situ hybridization...... age from an unexposed recreational area. Exposure to lead was assessed by determination of lead concentrations in blood (PbB) by atomic absorption spectrophotometry, whereas the level of selenium (Se) in serum was detected by using graphite furnace atomic-absorption spectrometry. The frequency of MN...... was determined by the cytokinesis-block MN assay and fluorescence in situ hybridization performed using a specific pan-centromeric probe. Environmental exposure to lead resulted in significantly increased levels of PbB (5.29 +/- 2.09 versus 3.45 +/- 1.20 microg/dl in controls), although the average level...

  20. Iodide-assisted total lead measurement and determination of different lead fractions in drinking water samples.

    Science.gov (United States)

    Zhang, Yuanyuan; Ng, Ding-Quan; Lin, Yi-Pin

    2012-07-01

    Lead and its compounds are toxic and can harm human health, especially the intelligence development in children. Accurate measurement of total lead present in drinking water is crucial in determining the extent of lead contamination and human exposure due to drinking water consumption. The USEPA method for total lead measurement (no. 200.8) is often used to analyze lead levels in drinking water. However, in the presence of high concentration of the tetravalent lead corrosion product PbO(2), the USEPA method was not able to fully recover particulate lead due to incomplete dissolution of PbO(2) particles during strong acid digestion. In this study, a new procedure that integrates membrane separation, iodometric PbO(2) measurement, strong acid digestion and ICP-MS measurement was proposed and evaluated for accurate total lead measurement and quantification of different lead fractions including soluble Pb(2+), particulate Pb(II) carbonate and PbO(2) in drinking water samples. The proposed procedure was evaluated using drinking water reconstituted with spiked Pb(2+), spiked particulate Pb(II) carbonate and in situ formed or spiked PbO(2). Recovery tests showed that the proposed procedure and the USEPA method can achieve 93-112% and 86-103% recoveries respectively for samples containing low PbO(2) concentrations (0.018-0.076 mg Pb per L). For samples containing higher concentrations of PbO(2) (0.089-1.316 mg Pb per L), the USEPA method failed to meet the recovery requirement for total lead (85-115%) while the proposed method can achieve satisfactory recoveries (91-111%) and differentiate the soluble Pb(2+), particulate Pb(II) carbonate and PbO(2).

  1. Impact of lead pollution along road side soils : two decades after phasing out leaded gasoline

    Energy Technology Data Exchange (ETDEWEB)

    Li, L.Y. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Civil Engineering

    2003-07-01

    Tetra ethyl lead was phased out as a fuel additive more than 15 years ago. Since then, there has been a drastic drop in annual source indicators for lead. Despite the phasing out, the standard set in the British Columbia (B.C.) Contaminated Site Regulation continues to be exceeded by deposited lead concentrations along highway corridors. The risks must be mitigated by the Ministry of Transportation and Highways without consideration to the mobility of the contaminant. A project was initiated to determine the acceptability of leaving lead-contaminated roadside soil in place. Investigations revealed lead accumulations of up to 1628 milligrams per kilogram (mg/kg) in highway soils. Lead was discovered mainly in the top 30 centimetres of surface soil. Surface soil possesses a high adsorption capacity compared to deeper soils. It was revealed that the adsorption capacity for lead by highway soils was 3 to 10 times higher than the amount currently deposited on site. Desorption tests were conducted, using H{sub 2}O at pH 5.5 and HNO{sub 3} solution of pH 4.0 as leaching solutions which yielded leachant concentrations below 2 parts per million (ppm) with a detection limit of 0.1 ppm. All sample leachates proved to be below the B.C. Environmental Drinking Water Standard (10 ppm in solution), despite the high total lead concentration found in the soil. The results suggest that there is very limited lead mobility in highway soil. Therefore, leaving lead contaminated soil in place is an acceptable option. 10 refs., 1 tab., 4 figs.

  2. Lead in New York City Community Garden Chicken Eggs: Influential Factors and Health Implications

    Science.gov (United States)

    Spliethoff, Henry M.; Mitchell, Rebecca G.; Ribaudo, Lisa N.; Taylor, Owen; Shayler, Hannah A.; Greene, Virginia; Oglesby, Debra

    2014-01-01

    Raising chickens for eggs in urban areas is becoming increasingly common. Urban chickens may be exposed to lead, a common urban soil contaminant. We measured lead concentrations in chicken eggs from New York City (NYC) community gardens and collected information on factors that might affect those concentrations. Lead was detected between 10 and 167 μg/kg in 48% of NYC eggs. Measures of lead in eggs from a henhouse were significantly associated (plead concentrations in soil. The association between soil and egg lead has been evaluated only once before, by a study of a rural region in Belgium. In our study, the apparent lead soil-to-egg transfer efficiency was considerably lower than that found in Belgium, suggesting that there may be important geographic differences in this transfer. We developed models that suggested that, for sites like ours, lead concentrations in >50% of eggs from a henhouse would exceed store-bought egg concentrations (lead concentrations >120 mg/kg, and that the concentration in one of six eggs from a henhouse would exceed a 100 μg/kg guidance value at soil lead concentrations >410 mg/kg. Our models also suggested that the availability of dietary calcium supplements was another influential factor that reduced egg lead concentrations. Estimates of health risk from consuming eggs with the lead concentrations we measured generally were not significant. However, soil lead concentrations in this study were lead transfer to chicken eggs and associated exposure are recommended for urban chicken keepers. PMID:24287691

  3. Polymorphism of lead oxoborate

    Energy Technology Data Exchange (ETDEWEB)

    Tyulyupa, A.G. [Middle School, Sablinskoe, Stavropol region, 356322 (Russian Federation); Voronov, V.V. [A.M. Prokhorov General Physics Institute RAS, 38 Vavilov Street, Moscow 119991 (Russian Federation); Fedorov, P.P., E-mail: ppfedorov@yandex.ru [A.M. Prokhorov General Physics Institute RAS, 38 Vavilov Street, Moscow 119991 (Russian Federation)

    2015-07-20

    Highlights: • Pb{sub 4}B{sub 2}O{sub 7} melt undergoes statistical undercooling. • Orthorhombic nonlinear optical crystal Pb{sub 4}O(BO{sub 3}){sub 2} is the metastable γ-polymorph. • Temperature of metastable melting of γ-Pb{sub 4}O(BO{sub 3}){sub 2} is equal to 530 °C. - Abstract: The study of lead borate melt crystallization by differential thermal analysis (DTA) and X-ray diffraction analysis has shown that, for Pb{sub 4}O(BO{sub 3}){sub 2} (or 4PbO·B{sub 2}O{sub 3}) stoichiometric compound, its well-known orthorhombic modification (non-centrosymmetric Aba2 space symmetry group (SSG), a = 15.472(1), b = 10.802(1), c = 9.9486(6) Å unit cell parameters) is metastable. It forms from the undercooled melt and has a melting point of 530 ± 5 °C.

  4. Nanocrystals for luminescent solar concentrators.

    Science.gov (United States)

    Bradshaw, Liam R; Knowles, Kathryn E; McDowall, Stephen; Gamelin, Daniel R

    2015-02-11

    Luminescent solar concentrators (LSCs) harvest sunlight over large areas and concentrate this energy onto photovoltaics or for other uses by transporting photons through macroscopic waveguides. Although attractive for lowering solar energy costs, LSCs remain severely limited by luminophore reabsorption losses. Here, we report a quantitative comparison of four types of nanocrystal (NC) phosphors recently proposed to minimize reabsorption in large-scale LSCs: two nanocrystal heterostructures and two doped nanocrystals. Experimental and numerical analyses both show that even the small core absorption of the leading NC heterostructures causes major reabsorption losses at relatively short transport lengths. Doped NCs outperform the heterostructures substantially in this critical property. A new LSC phosphor is introduced, nanocrystalline Cd(1-x)Cu(x)Se, that outperforms all other leading NCs by a significant margin in both small- and large-scale LSCs under full-spectrum conditions.

  5. Chromosome distribution studies after inorganic lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Verschaeve, L.; Driesen, M.; Kirsch-Volders, M.; Hens, L.; Susanne, C.

    1979-06-19

    We studied the chromosome distribution in persons professionally exposed to inorganic lead. The degree of lead exposure was evaluated by biochemical measurements and cytogenetic analysis. The chromosome distribution was analyzed from trypsin banded karyotypes; in particular we studied centromere distances (delta2) and centromere-metaphase-center distances (d2) which were obtained by computer-aided mathematical transformation of the individual metaphase coordinates. Higher concentrations of blood lead and urine delta-ALA and a statistically significant increase in aneuploidy, hypoploidy, and type-B chromosome aberrations revealed appreciable exposure although none of the subjects showed signs of excessive lead absorption. However, study of the chromosome distribution showed no major differences with that of the controls indicating that lead acts preferentially (directly or indirectly) on the chromosomes rather than on the spindle apparatus. A dissociation of the acrocentric chromosomes was observed in the lead group when compared with the controls. This is thought to reflect a secondary action of lead on the nucleolar organizer regions.

  6. Lead sources and transfer in the coastal Mediterranean: evidence from stable lead isotopes in marine particles

    Science.gov (United States)

    Alleman, L. Y.; Hamelin, B.; Véron, A. J.; Miquel, J.-C.; Heussner, S.

    Time series of settling and suspended particles have been collected by sediment traps and in situ pumps respectively, under contrasted hydrographic conditions in the Gulf of Lions and the Ligurian Sea, northwestern Mediterranean. Lead concentrations measured in sediment trap samples vary from 41±7 ppm in the Ligurian Sea to 58±10 ppm in the Gulf of Lions. These concentrations, 2-10 times lower than those measured previously in the Gulf of Lions, reflect the reduction of lead fallout from gasoline during the last decade. While atmospheric lead still originates mainly from anthropogenic emissions (automotive and industrial exhausts), stable lead isotopes demonstrate that anthropogenic and lithogenic lead are in similar proportions in the marine particles from the northwestern Mediterranean. Sequential extraction analyses performed on trap samples suggest that the isotopic variations can be explained by a three-component mixing between anthropogenic, natural soluble, and natural refractory sources. In the suspended particulate matter from the Gulf of Lions, lead concentrations range from 0.2 to 30 ng/ l, with isotopic compositions comparable to those of the settling particles ( 206Pb/ 207Pb from 1.165 to 1.178). This indicates a common origin in these two types of particles, probably mainly controlled by the Rhône River discharge and by resuspension processes on the continental shelf. By contrast, lead concentrations are lower in the suspended matter samples from the Ligurian Sea (0.5 to 1.7 ng/ l). In this case, the isotopic signature (1.165±0.002) is in equilibrium with the dissolved fraction, as previously found in other oligotrophic sites in the open ocean, where the suspended particles are mainly of biological origin and lead essentially authigenic in these particles.

  7. Leading- and next-to-leading-order lateral Casimir force on corrugated surfaces

    CERN Document Server

    Cavero-Pelaez, Ines; Parashar, Prachi; Shajesh, K V

    2008-01-01

    We derive explicit analytic expressions for the lateral force for two different configurations with corrugations, parallel plates and concentric cylinders. By making use of the multiple scattering formalism, we calculate the force for a scalar field under the influence of a delta-function potential that has sinusoidal dependence in one direction simulating the corrugations. By making a perturbative expansion in the amplitude of the corrugation we find the leading order for the corrugated concentric cylinders and the next-to-leading order for the corrugated parallel plates.

  8. Chronic lead poisoning in steers eating silage contaminated with lead shot - diagnostic criteria

    Energy Technology Data Exchange (ETDEWEB)

    Rice, D.A.; McLoughlin, M.F.; Blanchflower, W.J.; Thompson, T.R.

    1987-10-01

    Lead ingestion is one of the most common causes of poisoning in cattle. Toxicity results most commonly from the consumption of a single high dose of lead although cumulative toxicity resulting from the ingestion of small doses over a prolonged time also occurs. The sources of lead most commonly involved in disease outbreaks are paint, batteries, felt, linoleum and oil. It has traditionally been held that ingested metallic lead does not present a major toxicity risk to cattle because of its low solubility in the rumen and reticulum. More recent evidence suggests that lead shot, if present in silage, can induce toxicity when such silage is eaten by cattle. This communication describes a poisoning outbreak in steers eating lead shot contaminated grass silage. It presents and discusses the limitations of the criteria used for arriving at a diagnosis, including the use of whole blood amino levulinic acid dehydratase (ALAD) concentrations in fresh whole blood and after reactivation with dithiothreitol. Three are differences of opinion, in the literature, regarding the response of erythrocyte ALAD to ingested lead in the bovine. Consequently the results of a small lead feeding trial are also reported here. These results demonstrate a large ALAD response to lead ingestion and justify the use of this test in the confirmation of field cases of lead poisoning in cattle such as the one reported here.

  9. Lead and osteoporosis: Mobilization of lead from bone in postmenopausal women

    Energy Technology Data Exchange (ETDEWEB)

    Silbergeld, E.K. (Environmental Defense Fund, WA (USA)); Schwartz, J. (Environmental Protection Agency, Washington, DC (USA)); Mahaffey, K. (National Institute of Environmental Health Sciences, Research Triangle Park, NC (USA))

    1988-10-01

    Although it has been known that humans accumulate lead in bone, mineralized tissue has been considered primarily as a sequestering compartment and not as a site of toxic action for lead. However, experimental data indicate that bone lead can be released during conditions of demineralization, such as pregnancy and lactation. We have examined lead status in women, before and after menopause, using the NHANES II dataset compiled between 1976 and 1980. In 2981 black and white women there was a highly significant increase in both whole blood and calculated plasma lead concentrations after menopause. The results indicate that bone lead is not an inert storage site for absorbed lead. Moreover, lead may interact with other factors in the course of postmenopausal osteoporosis, to aggravate the course of the disease, since lead is known to inhibit activation of vitamin D, uptake of dietary calcium, and several regulatory aspects of bone cell function. The consequences of this mobilization may also be of importance in assessing the risks of maternal lead exposure to fetal and infant health.

  10. High medical consultation rates of lead workers after industrial dispute over lead effects

    Energy Technology Data Exchange (ETDEWEB)

    Araki, S.; Murata, K.; Yanagihara, S.; Ushio, K.

    1982-02-01

    Medical consultation rates were compared between a group of lead workers and two groups of non-lead workers in a newspaper company where a serious industrial dispute took place over health effects of lead three years before this study. The comparison was also made within the group of lead workers. Maximal blood lead concentrations (PbBs) ranged from 0.1 ..mu..mol/kg to 3.6 ..mu..mol/kg with an average of 1.3 ..mu..mol/kg in the past three years. The consultation rate of lead workers was significantly higher than that of both the non-lead workers, when the number of workers who consulted physicians or dentists once or more for a year per 100 workers was compared. Disease-specific consultation rates were also higher in lead workers for seven categories of diseases and injuries such as hypertensive disease and peptic ulcers. When lead workers were divided into three groups by PbB or erythrocytes delta-aminolevulinic acid dehydratase (ALAD) levels, however, no significantly high rate was found in the higher PbB groups nor lower ALAD groups in terms of general and disease-specific consultation rates. It was concluded that the industrial dispute might have been a major cause of the high consultation rate of lead workers.

  11. Blood Lead Levels and Health Problems of Lead Acid Battery Workers in Bangladesh

    Directory of Open Access Journals (Sweden)

    Sk. Akhtar Ahmad

    2014-01-01

    Full Text Available Introduction. Use of lead acid battery (LAB in Bangladesh has risen with sharp rise of motor vehicles. As result, manufacture of LAB is increasing. Most of the lead used by these industries comes from recycling of LAB. Workers in LAB industry are at risk of exposure lead and thus development of lead toxicity. Objective. The objective of this study was to measure the blood lead concentration and to assess the magnitude of health problems attributable to lead toxicity among the LAB manufacturing workers. Methods. A cross-sectional study was conducted among the workers of LAB manufacturing industries located in Dhaka city. Result. Mean blood lead level (BLL among the workers was found to be high. They were found to be suffering from a number of illnesses attributable to lead toxicity. The common illnesses were frequent headache, numbness of the limbs, colic pain, nausea, tremor, and lead line on the gum. High BLL was also found to be related to hypertension and anemia of the workers. Conclusion. High BLL and illnesses attributable to lead toxicity were prevalent amongst workers of the LAB manufacturing industries, and this requires attention especially in terms of occupational hygiene and safety.

  12. The effect of lead in bone densitometry

    Science.gov (United States)

    Popovic, Marija; McNeill, Fiona E.; Webber, Colin E.; Chettle, David R.

    2004-01-01

    Dual energy X-ray absorptiometry (DXA) is presently considered the standard technique for diagnosis of osteoporosis. It has been suggested that the presence of lead interferes with the accurate measurement of bone mineral density (BMD) by DXA because of the increased attenuation and that an accurate measurement of BMD cannot be determined unless the patient's bone lead content of patients is known. We performed DXA measurements on plaster of Paris phantoms and a Hologic Spine phantom in combination with polyester resin doped with various concentrations of lead. At lead levels which correspond to bone concentrations in occupationally exposed individuals, the suggested increase in densitometric BMD was not detected. Numerical calculations show that the effect of the lead depends upon the two energies of the X-ray beam of a particular device. The discrepancy between the actual and the densitometric BMD increases linearly and is about 0.3% at 100 ppm. Such change cannot be detected by the Hologic QDR 4500A, the device used for this experiment.

  13. Drowning: a leading killer!

    Directory of Open Access Journals (Sweden)

    Nuno Domingos Garrido

    2016-10-01

    Full Text Available Drowning kills at least 372,000 people worldwide every year and is the 3rd leading cause of unintentional death, accounting for 7% of all deaths stemming from accidents (WHO, 2014. Conceptually, “drowning” is a complex and multi-faceted phenomenon, characterized as a chain of events (Bierens, 2006. Drowning is defined as the process of experiencing respiratory impairment from immersion or submersion in liquid. Research on drowning as a phenomenon presents several difficulties - most of all, that global data concerning the number of occurrences are not accurate. Nevertheless, detailed analysis of the registered incidents allows the identification of risk factors of drowning. An in-depth analysis of the risk factors is the basis for the creation of targeted and effective strategies to prevent drowning. Due to variability of situations which could lead to a drowning episode, experts suggest the adoption of a multi-layer prevention model, rather than opting for isolated measures, since no single measure can prevent all deaths and injuries caused by submersion. Among the preventive measures we would like to emphasize instruction in swimming and water safety. So, what does "knowing how to swim" really mean? Some authors define mastery of this competence as swimming a given distance, while others put the emphasis on how this/any given distance is swum (Stallman, Junge, & Blixt, 2008. It has long been realized that there is no contradiction between learning those competencies which make a person less susceptible to drowning and those competencies which prepare the path towards higher levels of performance and competition. Aquatic movement researchers and practitioners and drowning prevention researchers and practitioners, share in the responsibility for drowning prevention though they are often unaware of it. The question “What should be taught to children?” is too infrequently asked. There remains great variation in what is taught and programs

  14. Leading Your Leaders

    Science.gov (United States)

    Hale, Wayne N.

    2008-01-01

    life is good. More often when an unbelievably difficult test fails, we are left with a very long discussion of why and what was wrong in the design or execution of the test. Make sure that the test is well defined. Even then, it is important to explain to your leaders what inherent accuracy (or error) the test conditions or equipment have and what the assumptions or initial conditions were for the test. Test results without a good understanding of the test's accuracy or the pedigree of the test assumptions are worth very little. Finally, there is flight test data. Always limited, never at the edge of the envelope, it still shows how the real hardware works in a combined environment. Flight experience is dangerous because it typically doesn't show how close to the edge of the cliff the equipment is operating, but it does demonstrate how the hardware really works. A flight test is the ultimate test, again taken with the knowledge that it is probably not the extreme but something more like the middle of the environmental and systems performance. Good understanding of a problem and its solution always relies on a combination of all these methods. Be sure to lead your leaders by using all the tools you have at your disposal. At the end of the day, decisions in space flight always come down to a risk trade. Our business is not remotely safe, not in the sense that the public, the media, or our legislators use the term. Everything we do has a risk, cost, schedule, or performance trade-off. For your leaders to make an appropriate decision, you need to educate them, lead them, talk with them, and engage them in the discussion until full understanding takes place. It's your job. *

  15. A SURVEY ON LEAD INTOXICATION IN LEAD MINERS

    Directory of Open Access Journals (Sweden)

    P. Meshgi

    1972-12-01

    Full Text Available A survey on lead intoxication in lead mine workers was carried out among Khanehsorme, lead miners in NajafAabad and also in Ab-bagh lead miners in Shahreza, both located in district of Esfahan, Iran. The studies were carried out on 62 miners out of 82 employees in Khanehsorme, 25 miners out of 27 employees in Ab-bagh lead miners and 47 rural inhabitants in the surroundings of mines were selected as the Control group. Clinical examinations were done. Age and sex group, working hours, type of work, and duration of service and previous occupation of workers were questioned. The determination of lead in urine was done according to Truhaut et Boudene's method and the content of blood Hemoglobin was performed according to Sali method. Results obtained in lead miners in comparison with the control group showed the absorption of lead and consequently lead intoxication was observed some extent.

  16. Environmental lead exposure among preschool children in Shanghai, China: blood lead levels and risk factors.

    Directory of Open Access Journals (Sweden)

    Jia Cao

    Full Text Available OBJECTIVE: To determine blood lead levels and to identify related risk factors among children in Shanghai; to explore the lead change trend of children after industrial transformation and to provide data for policy development to control environmental lead pollution in Shanghai. METHODS: A stratified-clustered-random sampling method was used. A tungsten atomizer absorption spectrophotometer was employed to determine blood lead levels. RESULTS: The arithmetic mean, geometric mean and median of blood lead levels of 0- to 6-year-old children from Shanghai were 22.49 µg/L, 19.65 µg/L and 19.5 µg/L, including 0.26% (6/2291 with concentrations ≥100 µg/L and 2.7% (61/2291 with concentrations ≥50 µg/L. Boys' levels (23.57 µg/L were greater than those of girls (21.2 µg/L. The blood lead levels increased with age. This survey showed that the Chongming district was the highest and Yangpu district was the lowest, this result is completely opposite with the earlier survey in Shanghai. Risk factors for lead contamination included housing environment, parents' education levels, social status, hobbies, and children's nutritional status. CONCLUSIONS: The blood lead levels of children in Shanghai were lower than the earlier data of Shanghai and those of published studies in China, but higher than the blood lead levels of developed countries. The blood lead levels of urban districts are higher than the central districts with the industrial transformation. Society and the government should take an active interest in childhood lead poisoning of urban areas.

  17. Lifetime modelling of lead acid batteries

    DEFF Research Database (Denmark)

    Bindner, H.; Cronin, T.; Lundsager, P.

    2005-01-01

    , therefore, lead to uncertainty in the viability of the system in the long term. This report details the work undertaken to investigate and develop two different battery life prediction methodologies withspecific reference to their use in hybrid renewable energy systems. Alongside this, results from battery...... been part of the European Union Benchmarking research project (ENK6-CT-2001-80576), funded by theEuropean Union, the United States and Australian governments together with other European states and other public and private financing bodies. The project has concentrated on lead acid batteries...

  18. Concentration and health risk of heavy metals in crops and soils in a zinc-lead mining area in southwest mountainous regions%西南山地铅锌矿区耕地土壤和谷类产品重金属含量及健康风险评价

    Institute of Scientific and Technical Information of China (English)

    杨刚; 沈飞; 钟贵江; 谢丽苹; 王应军; 伍钧

    2011-01-01

    To evaluate the influence of mining activities on heavy metal contamination and health risks in a mining affected area,Pb,Zn,Cd,Cr,Cu and As in soils(dry land and irrigated land) and dominant crops were monitored and analyzed in Ganluo,Sichuan Province.The Nemero comprehensive pollution index was employed to evaluate the quality of the soil.The health risks of the above-mentioned heavy metals to adults and children by food ingestion were assessed using the MMSOILS model.The results showed that(1) the farmlands in the zinc-lead mining area were contaminated seriously by heavy metals,especially Pb、Zn、Cd and As.The concentrations of As in dry land soils and Cd in irrigated land were 11.45 and 7.38 times higher than those of the National Soil Quality Standard-GradeⅡ.Compound contamination of heavy metals in the soils was extremely severe.The Nemero index of dry land was higher than that of the irrigated land.(2) Compared to the Food Hygiene Standards,high pollution risks from the above-mentioned heavy metals,especially from Pb,Cd and As,existed in grains from the locally cultivated crops.(3) The average individual health risk of heavy metals for children and adults were near the maximum acceptable level set by the US EPA,The calculated critical threshold in soil for adults was higher than that for children.The order of individual risk index for the health of children and adult was AsPbCdCuZnCr,in which As,Pb,Cd had an especially high risk for adults,and As,Pb,Cd,Cu,Zn had an especially high risk for children.Moreover,children were more sensitively affected by heavy metals from food ingestion.Therefore,attention should be paid to children's health monitoring in such areas.%对西南山地某铅锌矿区耕地土壤(旱地和水田)和主要谷物类产品(小麦、玉米和稻米)进行取样调查,分别测定并分析了土壤和谷物中Pb、Zn、Cu、Cr、Cd、As等重金属的含量.同时,通过Nemero综合污染指数评价了矿

  19. How does lead induce male infertility?

    Directory of Open Access Journals (Sweden)

    Ping-Chi Hsu

    2011-01-01

    Full Text Available An important part of male infertility of unknown etiology may be attributed to various environmental and occupational exposures to toxic substances, such as lead. The reproductive effects of lead are complex and appear to involve multiple pathways, not all of which are fully understood. It is still unclear, for example, if male reproductive issues in lead-exposed persons are mostly related to the disruption of reproductive hormones, whether the problems are due to the lead’s direct effects on the gonads, or both? This question has been difficult to answer, because lead, especially at high levels, may adversely affect many human organs. Although lead can potentially reduce male fertility by decreasing sperm count and motility, inducing abnormal morphology and affecting functional parameters; not all studies have been able to clearly demonstrate such findings. In addition, research has shown that the blood-testis barrier can protect testicular cells from direct exposure to high levels of blood lead. For these reasons and considering the wide spectrum of lead toxicity on reproductive hormones, the present review suggests that lead’s main influence on male reproduction probably occurs by altering the reproductive hormonal axis and the hormonal control on spermatogenesis, rather than by a direct toxic effect on the seminiferous tubules of the testes. As blood lead concentrations below the currently accepted worker protection standard may still adversely affect male fertility, future studies should aim to establish more concrete links between lead exposure (especially at low levels and subsequent male infertility. Research should also pay more attention to lead’s effects on reducing male fertility rates based on not only hormonal axis alteration, but also on the changes in sperm characteristic among exposed subjects.

  20. Lead hazard among ironworkers: dismantling lead-painted elevated subway line in New York City

    Energy Technology Data Exchange (ETDEWEB)

    Fischbein, A.; Daum, S.M.; Davidow, B.

    1978-07-01

    Flame cutting of lead-painted steel structures may be associated with considerable lead exposure. In this study, an outbreak of lead poisoning among ironworkers dismantling an elevated subway line in New York City is described. Industrial hygiene evaluation of the respirators showed that inadequate equipment was the cause of the subsequent occupational disease. In the assessment of the lead-induced effects on the hematopoietic system, a new screening test--erythrocyte zinc protoporphyrin determination--was employed, utilizing a portable field device (hematofluorometer) on which an instantaneous reading of ZPP (zinc protoporphyrin) concentration is obtained. Correlative data between ZPP and blood lead are presented, demonstrating that ZPP determinations may improve and simplify the task of screening and monitoring populations chronically exposed to lead. The effect of lead on the biosynthesis of heme was also assessed in five workers, by investigating the functional capacity of the hepatic cytochrome P-450 system through drug metabolism studies before and after chelation therapy. The effect on this system was considered minimal. Environmental studies showed that very high amounts of lead dusts were generated by the demolition process, but did not present any significant hazard to people residing in the vicinity. It is emphasized that combined medical and industrial hygiene surveillance is essential for the safe management of such work operation, and workers engaged in such operations require proper respiratory equipment to minimize the risk of increased lead absorption.

  1. Sublethal effects of chronic lead ingestion in mallard ducks

    Science.gov (United States)

    Finley, M.T.; Dieter, M.P.; Locke, L.N.

    1976-01-01

    Mallard drakes (Anas platyrhynchos) fed 1, 5, or 25 ppm lead nitrate were bled and sacrificed at 3-wk intervals. No mortality occurred, and the pathologic lesions usually associated with lead poisoning were not found. Changes in hematocrit and hemoglobin concentration did not occur. After 3-wk ducks fed 25 ppm lead exhibited a 40% inhibition of blood delta-aminolevulinic acid dehydratase activity that persisted through 12 wk exposure. After 12 wk treatment similar enzyme inhibition was present in the ducks fed 5 ppm lead. At 3 wk there was a small accumulation of lead (less than 1 ppm) in the liver and kidneys of ducks fed 25ppm lead; no further increases occurred throughout the exposure. No significant accumulation of lead occurred the the tibiae or wing bones. Groups of ducks fed 5 and 25 ppm diets for 12 wk were placed on clean feed and examined through a 12 wk posttreatment period. After 3 wk on clean diet delta-aminolevulinic acid dehydratase activity and lead concentrations in the blood had returned to pretreatment levels. Even though lead concentrations in the blood, soft organs and bone were low, a highly significant negative correlation between blood lead and blood enzyme activity was obtained. This enzyme bioassay should provide a sensitive and precise estimate for monitoring lead in the blood for waterflow.

  2. Environmentally sound technologies for recycling secondary lead

    Science.gov (United States)

    Andrews, D.; Raychaudhuri, A.; Frias, C.

    Advances in hydrometallurgy are providing increasingly simple means for controlling the entire lead chain from concentrate to recycled lead. Used in parallel with pyrometallurgy, these processes allow furnace temperatures to be reduced to the minimum, which is essential for casting or alloying. Fumes and atmospheric pollution are minimized, furnace slags are digested, and most residues (other than purification cements) are non-toxic and convertible into marketable products. These new processes provide the cleanest and healthiest practicable means for recycling lead from batteries. By substituting melting for smelting, the heat requirement and cycle time per charge are reduced by more than half. A new hydrometallurgical plant could be installed alongside an existing pyrometallurgical plant without interference, doubling its potential capacity when operational (and more, if electrowinning is used). Over 99.5% of the lead originally present is recovered in tests of a combined PLACID-pyro plant. The average purity of electrowon PLACID lead is 99.995%. Results from the PLINT process should be similar. The purity of the lead chain can thereby be sustained through recycling. Perfect solid/paste separation is not mandatory, and PLINT-type plant units can be of any size. Such processes constitute a good basis for development of clean processes, which are suitable for use in Asian societies.

  3. Assessment of leaching potential of highly leaded jewelry.

    Science.gov (United States)

    Weidenhamer, Jeffrey D; Newman, Breinn E; Clever, Ashley

    2010-05-15

    Lead is a potent neurotoxin particularly toxic to young children, and in response to recent poisonings of children and high levels of lead contamination in children's jewelry, US regulatory standards for lead content in these items have become much more stringent. Parents are often advised to throw out suspect items in the trash. While household wastes are generally exempt from consideration as hazardous waste, the potential for leaching of hazardous quantities of lead from such items is unknown. A modified Toxicity Characteristic Leaching Procedure (TCLP), in which intact jewelry components were subjected to leaching, was used to evaluate the potential for leaching of lead from highly leaded jewelry. Of 62 jewelry components tested, 61 exceeded the US regulatory standard for lead of 5mg/L, and leachate lead concentrations averaged 1460 mg/L. Twenty-six of the component items tested yielded TCLP lead concentrations exceeding 1000 mg/L. These results demonstrate that highly leaded jewelry items may leach significant amounts of lead, and provide another reason to remove lead from these products. Furthermore, these results suggest that while the volume of such items in the municipal solid waste (MSW) stream is small, they have the potential to contribute significant quantities of lead to MSW leachates.

  4. Abnormal distribution of lead in amyotrophic lateral sclerosis--reestimation of lead in the cerebrospinal fluid.

    Science.gov (United States)

    Conradi, S; Ronnevi, L O; Nise, G; Vesterberg, O

    1980-12-01

    The lead concentration in CSF was determined by flameless atomic absorption spectrophotometry in 16 ALS patients and 22 control cases. The mean values were 0.69 +/- 0.55 (ALS) and 0.41 +/- 0.37 (controls), P controls.

  5. Lead pollution and its sources along the Turkish coast of the Black Sea

    Directory of Open Access Journals (Sweden)

    M. UNSAL

    2012-12-01

    Full Text Available Lead pollution and its sources have been investigated in the south-eastern and south-western Black Sea. Surficial sediments and mussels were collected in different seasons of the year from the south-eastern and south-western Black Sea and analysed for their lead contents.In the south-eastern Black Sea sediments from the easternmost and from the central stations contained the highest lead concentrations. Sediments contained 8 to 10 times the lead concentrations of sediments from the south-west. Samples taken from rivers, streams and effluents had especially high lead concentrations. The highest lead concentrations were found in sediments collected in October and December.Lead concentrations in mussels from the south-eastern coast were comparatively lower compared to those from the south-western coast. The highest average values occurred in December and in October.In the south-western Black Sea, the highest lead concentrations in sediments were obtained in those from Inebolu, followed by those from around Zonguldak. The concentrations increased from the middle to the west of the southern Black Sea coast, possibly due to the effect of the Danube River. Sediments taken in September had the highest lead concentrations, followed by samples taken in December.Very high lead concentrations (> 10 μ g g-1 were observed in mussels from those stations where the sediments also contained high concentrations. Mussels had their highest lead concentrations in January and April.

  6. Lead pollution and its sources along the Turkish coast of the Black Sea

    Directory of Open Access Journals (Sweden)

    M. UNSAL

    2001-12-01

    Full Text Available Lead pollution and its sources have been investigated in the south-eastern and south-western Black Sea. Surficial sediments and mussels were collected in different seasons of the year from the south-eastern and south-western Black Sea and analysed for their lead contents. In the south-eastern Black Sea sediments from the easternmost and from the central stations contained the highest lead concentrations. Sediments contained 8 to 10 times the lead concentrations of sediments from the south-west. Samples taken from rivers, streams and effluents had especially high lead concentrations. The highest lead concentrations were found in sediments collected in October and December. Lead concentrations in mussels from the south-eastern coast were comparatively lower compared to those from the south-western coast. The highest average values occurred in December and in October. In the south-western Black Sea, the highest lead concentrations in sediments were obtained in those from Inebolu, followed by those from around Zonguldak. The concentrations increased from the middle to the west of the southern Black Sea coast, possibly due to the effect of the Danube River. Sediments taken in September had the highest lead concentrations, followed by samples taken in December. Very high lead concentrations (> 10 μ g g-1 were observed in mussels from those stations where the sediments also contained high concentrations. Mussels had their highest lead concentrations in January and April.

  7. High medical consultation rates of lead workers after industrial dispute over lead effects

    Energy Technology Data Exchange (ETDEWEB)

    Araki, S.; Murata, K.; Yanagihara, S.; Ushio, K.

    1982-02-01

    Medical consultation rates were compared between a group of lead workers (346 males) and two groups of non-lead workers (317 and 329 males) in a newspaper company where a serious industrial dispute took place over health effects of lead three years before this study. The comparison was also made within the group of lead workers. Maximal blood lead concentrations (PbBs) ranged from 0.1 mumol/kg to 3.6 mumol/kg (74 microgram/100 g) with an average of 1.3 mumol/kg in the past three years. Ages averaged 35 years in lead workers, and 34 and 30 years in non-lead workers, the ranges being 19-55 years in all. The consultation rate of lead workers was significantly higher than that of both the non-lead workers (P less than 0.001), when the number of workers who consulted physicians or dentists once or more for a year per 100 workers (general consultation rate) was compared. Disease-specific consultation rates were also higher in lead workers for seven categories of diseases and injuries such as hypertensive disease and peptic ulcers. When lead workers were divided into three groups by PbB or erythrocytes delta-aminolevulinic acid dehydratase (ALAD) levels, however, no significantly high rate was found in the higher PhB groups not lower ALAD groups in terms of general and disease-specific consultation rates. It was concluded that the industrial dispute might have been a major cause of the high consultation rate of lead workers.

  8. Impact of the California lead ammunition ban on reducing lead exposure in golden eagles and turkey vultures.

    Directory of Open Access Journals (Sweden)

    Terra R Kelly

    Full Text Available Predatory and scavenging birds may be exposed to high levels of lead when they ingest shot or bullet fragments embedded in the tissues of animals injured or killed with lead ammunition. Lead poisoning was a contributing factor in the decline of the endangered California condor population in the 1980s, and remains one of the primary factors threatening species recovery. In response to this threat, a ban on the use of lead ammunition for most hunting activities in the range of the condor in California was implemented in 2008. Monitoring of lead exposure in predatory and scavenging birds is essential for assessing the effectiveness of the lead ammunition ban in reducing lead exposure in these species. In this study, we assessed the effectiveness of the regulation in decreasing blood lead concentration in two avian sentinels, golden eagles and turkey vultures, within the condor range in California. We compared blood lead concentration in golden eagles and turkey vultures prior to the lead ammunition ban and one year following implementation of the ban. Lead exposure in both golden eagles and turkey vultures declined significantly post-ban. Our findings provide evidence that hunter compliance with lead ammunition regulations was sufficient to reduce lead exposure in predatory and scavenging birds at our study sites.

  9. Tendencia de los niveles de plomo en la atmósfera de la zona metropolitana de la Ciudad de México: 1988-1998 Trends in atmospheric concentrations of lead in the Metropolitan Area of Mexico City: 1988-1998

    Directory of Open Access Journals (Sweden)

    Marlene Cortez-Lugo

    2003-01-01

    Full Text Available OBJETIVO: Describir las tendencias del plomo atmosférico asociadas a la eliminación paulatina del plomo de la gasolina y el uso de convertidores catalíticos en el auto transporte de la Ciudad de México, de 1988 a 1998. MATERIAL Y MÉTODOS: Estudio de series de tiempo que incluye las mediciones atmosféricas de plomo que se obtuvieron, entre 1988 y 1998, de nueve estaciones de la red manual de monitoreo atmosférico de la Ciudad de México. Las intervenciones evaluadas fueron la introducción de gasolina Magnasin, el uso de convertidores catalíticos y el descenso en la concentración de plomo hasta su eliminación total de la gasolina utilizada en los auto transportes. Se describen las tendencias de plomo por monitor, por zona geográfica, utilizando un modelo de regresión que incorpora una estructura de auto-correlación. RESULTADOS: La introducción de gasolina sin plomo y de los convertidores catalíticos se asoció con un descenso en la concentración de plomo atmosférico en 23%, la reducción paulatina del plomo en la gasolina ocasionó una reducción acumulada de 89% en todas las zonas estudiadas. CONCLUSIONES: La introducción de la gasolina sin plomo ha logrado abatir las concentraciones ambientales de este contaminante de una manera importante.OBJECTIVE: To describe the trends in airborne lead levels and their association with the control measures implemented from 1988 to 1998 to phase out lead from gasoline that included the introduction of a lead-free gasoline and the use of catalytic converters in automobiles in Mexico City. MATERIAL AND METHODS: Data of atmospheric lead levels were obtained from the 9 field stations included in the local air quality monitoring network (RMMA. Trends for airborne lead are shown by monitor, monitoring area and for the entire metropolitan zone. Analysis of data was performed using linear regression models including autocorrelation analysis. The models were validated by standard diagnostic

  10. Lead analysis of waterfowl from Yukon Delta NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In 1995, WAES received funds from the Yukon Delta Ecosystem Team to analyze livers of waterfowl, other than spectacled eiders, for lead concentrations. Nineteen...

  11. Drinking Peroxide as 'Natural' Cure Leads to Dangerous Blood Clots

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163513.html Drinking Peroxide as 'Natural' Cure Leads to Dangerous Blood Clots ... 9, 2017 (HealthDay News) -- Ingesting high-concentration hydrogen peroxide as a "natural cure" or cleansing agent may ...

  12. Nuclear microprobe analysis of lead profile in crocodile bones

    Science.gov (United States)

    Orlic, I.; Siegele, R.; Hammerton, K.; Jeffree, R. A.; Cohen, D. D.

    2003-09-01

    Elevated concentrations of lead were found in Australian free ranging saltwater crocodile ( Crocodylus porosus) bone and flesh. Lead shots were found as potential source of lead in these animals. ANSTO's heavy ion nuclear microprobe was used to measure the distribution of Pb in a number of bones and osteoderms. The aim was to find out if elevated Pb concentration remains in growth rings and if the concentration is correlated with the blood levels recorded at the time. Results of our study show a very distinct distribution of accumulated Pb in bones and osteoderms as well as good correlation with the level of lead concentration in blood. To investigate influence of ion species on detection limits measurements of the same sample were performed by using 3 MeV protons, 9 MeV He ions and 20 MeV carbon ions. Peak to background ratios, detection limits and the overall 'quality' of obtained spectra are compared and discussed.

  13. Assessment of lead sources for waterfowl in Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Exposure to detrimental concentrations of lead has been documented in waterfowl in Alaska. In spectacled eiders (Somateria fischeri) and long-tailed ducks (Clangula...

  14. The Changing Way of Leading

    Science.gov (United States)

    Sytsma, Sandra

    2009-01-01

    This conceptual article explores the changing way of leading. It proposes that in contrast to the primarily outer actions that characterize educational change, the inner and outer dimensions of leaders are necessary to change what constitutes leading, thereby making it more appropriate to our times. The unfolding of leading actions and the…

  15. Lead in School Drinking Water.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC. Office of Water Programs.

    Lead levels in school drinking water merit special concern because children are more at risk than adults from exposure to lead. This manual provides ways in which school officials can minimize this risk. It assists administrators by providing: (1) general information on the significance of lead in school drinking water and its effects on children;…

  16. Bioremediation potential of spirulina: toxicity and biosorption studies of lead

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong; PAN Shan-shan

    2005-01-01

    This study examines the possibility of using live spirulina to biologically remove aqueous lead of low concentration (below 50 mg/L) from wastewater. The spirulina cells were first immersed for seven days in five wastewater samples containing lead of different concentrations, and the growth rate was determined by light at wavelength of 560 nm. The 72 h-EC50 (72 h medium effective concentration) was estimated to be 11.46 mg/L (lead). Afterwards, the lead adsorption by live spirulina cells was conducted. It was observed that at the initial stage (0-12 min) the adsorption rate was so rapid that 74% of the metal was biologically adsorbed. The maximum biosorption capacity of live spirulina was estimated to be 0.62 mg lead per 105 alga cells.

  17. [Characterization of language disorders in children with lead poisoning].

    Science.gov (United States)

    Gahyva, Dáphine Luciana Costa; Crenitte, Patrícia de Abreu Pinheiro; Caldana, Magali de Lourdes; Hage, Simone Rocha de Vasconcellos

    2008-01-01

    lead poisoning can have a negative impact on the neuropsychological functions, including language, due to the damage it causes to the development of the Central Nervous System. to verify the occurrence of language disorders in children who suffered from led poisoning and to verify the correlation between the lead concentration level in the blood and the language disorders presented by the children. language evaluation of 20 preschoolers, with lead concentration level in the blood above 10 microg/dl. 13 children presented language impairment involving only phonology or more than one language subsystem. The statistical analysis indicated that no correlation exists between the severity of the language impairment and the concentration levels of lead. the number of children with language impairment indicates lead poisoning as a risk factor for the present alterations, even though other risk factors for language disorders were found and the absence of correlation between the investigated variables.

  18. Bioremediation potential of spirulina: toxicity and biosorption studies of lead.

    Science.gov (United States)

    Chen, Hong; Pan, Shan-Shan

    2005-03-01

    This study examines the possibility of using live spirulina to biologically remove aqueous lead of low concentration (below 50 mg/L) from wastewater. The spirulina cells were first immersed for seven days in five wastewater samples containing lead of different concentrations, and the growth rate was determined by light at wavelength of 560 nm. The 72 h-EC50 (72 h medium effective concentration) was estimated to be 11.46 mg/L (lead). Afterwards, the lead adsorption by live spirulina cells was conducted. It was observed that at the initial stage (0-12 min) the adsorption rate was so rapid that 74% of the metal was biologically adsorbed. The maximum biosorption capacity of live spirulina was estimated to be 0.62 mg lead per 10(5) alga cells.

  19. Influence of lead on auxin-induced cell elongation

    Directory of Open Access Journals (Sweden)

    Marek Burzyński

    2014-01-01

    Full Text Available The influence of lead chloride on plant tissue growth is described. Lead reduced elongation of etiolated wheat coleoptile segments, green pea epicotyl fragments and etiolated and green sunflower hypocotyls. Green tissues were more susceptible to lead than etiolated ones. PbCl2 in a 10-4 M concentration significantly reduced plastic and elastic extensibility of the wheat coleoptile cell walls and diminished the hydration of sunflower hypocotyl segments. Auxin (indolyl-3-acetic acid - IAA applied in concentration optimal for growth of the particular tissues partly attenuated the inhibitory action of lead on elongation, plastic and elastic extensibility and water absorption. Auxin applied in supraoptimal concentrations did not abolish the inhibitory action of lead on tissue growth.

  20. Concentrator design to minimize LCOE

    Science.gov (United States)

    McDonald, Mark; Horne, Steve; Conley, Gary

    2007-09-01

    The Levelized Cost of Energy (LCOE) takes into account more than just the cost of power output. It encompasses product longevity, performance degradation and the costs associated with delivering energy to the grid tie point. Concentrator optical design is one of the key components to minimizing the LCOE, by affecting conversion efficiency, acceptance angle and the amount of energy concentrated on the receiver. Optical systems for concentrators, even those at high concentrations ( >350X) can be designed by straightforward techniques, and will operate under most circumstances. Adding requirements for generous acceptance angles, non-destructive off-axis operation, safety and high efficiency however, complicate the design. Furthermore, the demands of high volume manufacturing, efficient logistics, minimal field commissioning time and low cost lead to quite complicated, system level design trade-offs. The technology which we will discuss features an array of reflective optics, scaled to be fabricated by techniques used in the automotive industry. The design couples a two-element imaging system to a non-imaging total internal reflection tertiary in a very compact design, with generous tolerance margins. Several optical units are mounted in a housing, which protects the optics and assists with dissipating waste heat. This paper outlines the key elements in the design of SolFocus concentrator optics, and discusses tradeoffs and experience with various design approaches.

  1. Experimental study of blood lead kinetics in estuarine crocodiles (Crocodylus porosus) exposed to ingested lead shot.

    Science.gov (United States)

    Hammerton, K M; Jayasinghe, N; Jeffree, R A; Lim, R P

    2003-10-01

    A previous study of lead (Pb) contamination in estuarine crocodiles (Crocodylus porosus) in Kakadu National Park, Australia, found elevated Pb levels in bone and flesh from individuals caught in habitats where hunting with lead ammunition had occurred. Lead shot was suspected as the potential source of Pb in these animals. An investigation was designed to determine if crocodiles are capable of retaining and dissolving lead shot in their stomachs and absorbing the ionic Pb into the blood. Four of the six juvenile crocodiles (C. porosus) used in the experiment were fed an initial dose of five or ten lead shot each. Most of the lead shot were retained in the stomach over the 20-week experimental period, as confirmed by stomach lavage and radiography of the stomach region. From 13 to 30% of the original weight of individual lead shot had been eroded in that time. In vitro experiments confirmed that lead shot could be dissolved under conditions simulating those known for the crocodilian stomach. Blood Pb concentrations increased by an order of magnitude within a week after dosing three crocodiles with five lead shot each, and then attained steady-state equilibrium 5-20 weeks after dosing, with blood Pb steady-state levels ranging from 278 to 363 microg/dL. The blood Pb concentration-time curves in these crocodiles followed a one-compartment model with first-order loss kinetics that yielded an apparent biological half-life for Pb in blood of about 3.4 days. Throughout the experiment, the crocodiles remained in apparent good physical condition and displayed no clinical signs of Pb toxicosis. These observations, together with the very high blood Pb levels that were sustained for several months, suggest that crocodilians may possess a relatively high degree of resistance to Pb toxicity.

  2. Lead exposure reduction in workers using stabilizers in PVC manufacture: effects of a new encapsulated stabilizer

    Energy Technology Data Exchange (ETDEWEB)

    Fischbein, A. (Mount Sinai Medical Center, New York, NY); Thornton, J.C.; Berube, L.; Villa, F.; Selikoff, I.J.

    1982-09-01

    The handling of lead-containing powdered stabilizers may be associated with excessive lead exposure and occupational lead poisoning. An encapsulated stabilizer has been designed, which is shown to result in a marked reduction in air lead levels and a concommitant decrease in blood lead concentrations in a group of blender operators manufacturing PVC electrical cable coating.

  3. Lead isotopes in soils near five historic American lead smelters and refineries.

    Science.gov (United States)

    Rabinowitz, Michael B

    2005-06-15

    This survey of soil lead in the vicinity of old industrial sites examines how the stable isotope patterns vary among the sites according to the sources of the lead ore processed at each site. Lead smelters and refineries, which closed down decades ago, are the basis of this investigation. Samples were taken from near five old factory sites in Collinsville and Alton (Illinois), Ponderay (Idaho), East Chicago (Indiana) and Omaha (Nebraska). Historical records were searched for accounts of the sources of the lead. Lead concentrations were measured by atomic absorption flame spectrophotometry, and stable isotopic analysis was done by plasma ionization mass spectrometry. At every site visited, remnants of the old factories, in terms of soil lead pollution, could be found. In spite of potential complications of varying smelter feedstock sourced from mines of different geological age, it was possible to match the isotopic patterns in the soils with the documented sources of the ores. The Collinsville and Alton sites resembled Missouri lead. The Ponderay value was higher than major Bunker Hill, Idaho deposits, but closer to the minor, nearby Oreille County, Washington ores. Mostly Utah ore was used in East Chicago. The Omaha soil reflects lead from Mexico, Colorado and Montana.

  4. Developmental toxicity of lead-contaminated sediment to mallard ducklings

    Science.gov (United States)

    Hoffman, D.J.; Heinz, G.H.; Sileo, L.; Audet, D.J.; Campbell, J.K.; LeCaptain, L.J.

    2000-01-01

    Sediment ingestion has been identified as an important exposure route for toxicants in waterfowl. The toxicity of lead-contaminated sediment from the Coeur d'Alene River Basin (CDARB) in Idaho was examined on posthatching development of mallard (Anas platyrhynchos) ducklings for 6 weeks. Day-old ducklings received either untreated control diet, clean sediment (24%) supplemented control diet, CDARB sediment (3,449 ug/g lead) supplemented diets at 12% or 24%, or a positive control diet containing lead acetate equivalent to that found in 24% CDARB. The 12% CDARB diet resulted in a geometric mean blood lead concentration of 1.41 ppm (WW) with over 90% depression of red blood cell ALAD activity and over threefold elevation of free erythrocyte protoporphyrin concentration. The 24% CDARB diet resulted in blood lead of 2.56 ppm with over sixfold elevation of protoporphyrin and lower brain weight. In this group the liver lead concentration was 7.92 ppm (WW), and there was a 40% increase in hepatic reduced glutathione concentration. The kidney lead concentration in this group was 7.97 ppm, and acid-fast inclusion bodies were present in the kidneys of four of nine ducklings. The lead acetate positive control group was more adversely affected in most respects than the 24% CDARB group. With a less optimal diet (mixture of two thirds corn and one third standard diet), CDARB sediment was more toxic; blood lead levels were higher, body growth and liver biochemistry (TBARS) were more affected, and prevalence of acid-fast inclusion bodies increased. Lead from CDARB sediment accumulated more readily in duckling blood and liver than reported in goslings, but at given concentrations was generally less toxic to ducklings. Many of these effects are similar to ones reported in wild mallards and geese within the CDARB.

  5. Developmental toxicity of lead contaminated sediment to mallard ducks

    Science.gov (United States)

    Hoffman, D.J.; Heinz, G.H.; Sileo, L.; Audet, D.J.; Campbell, J.K.; LeCaptain, L.J.

    2000-01-01

    Sediment ingestion has been identified as an important exposure route for toxicants in waterfowl. The toxicity of lead-contaminated sediment from the Coeur d'Alene River Basin (CDARB) in Idaho was examined on posthatching development of mallard (Anas platyrhynchos) ducklings for 6 weeks. Day-old ducklings received either untreated control diet, clean sediment (24%) supplemented control diet, CDARB sediment (3,449 I?g/g lead) supplemented diets at 12% or 24%, or a positive control diet containing lead acetate equivalent to that found in 24% CDARB. The 12% CDARB diet resulted in a geometric mean blood lead concentration of 1.41 ppm (WW) with over 90% depression of red blood cell ALAD activity and over threefold elevation of free erythrocyte protoporphyrin concentration. The 24% CDARB diet resulted in blood lead of 2.56 ppm with over sixfold elevation of protoporphyrin and lower brain weight. In this group the liver lead concentration was 7.92 ppm (WW), and there was a 40% increase in hepatic reduced glutathione concentration. The kidney lead concentration in this group was 7.97 ppm, and acid-fast inclusion bodies were present in the kidneys of four of nine ducklings. The lead acetate positive control group was more adversely affected in most respects than the 24% CDARB group. With a less optimal diet (mixture of two thirds corn and one third standard diet), CDARB sediment was more toxic; blood lead levels were higher, body growth and liver biochemistry (TBARS) were more affected, and prevalence of acid-fast inclusion bodies increased. Lead from CDARB sediment accumulated more readily in duckling blood and liver than reported in goslings, but at given concentrations was generally less toxic to ducklings. Many of these effects are similar to ones reported in wild mallards and geese within the CDARB.

  6. Lead resistant bacteria: lead resistance mechanisms, their applications in lead bioremediation and biomonitoring.

    Science.gov (United States)

    Naik, Milind Mohan; Dubey, Santosh Kumar

    2013-12-01

    Lead (Pb) is non-bioessential, persistent and hazardous heavy metal pollutant of environmental concern. Bioremediation has become a potential alternative to the existing technologies for the removal and/or recovery of toxic lead from waste waters before releasing it into natural water bodies for environmental safety. To our best knowledge, this is a first review presenting different mechanisms employed by lead resistant bacteria to resist high levels of lead and their applications in cost effective and eco-friendly ways of lead bioremediation and biomonitoring. Various lead resistant mechanisms employed by lead resistant bacteria includes efflux mechanism, extracellular sequestration, biosorption, precipitation, alteration in cell morphology, enhanced siderophore production and intracellular lead bioaccumulation.

  7. Prevalence of lead disease among secondary lead smelter workers and biological indicators of lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Lilis, R. (City Univ. of New York); Fischbein, A.; Eisinger, J.

    1977-10-01

    The report concerns itself primarily with the assessment of medical and biochemical effects of chronic lead exposure and comparing the usefulness of various biological screening parameters. In addition it appraises the effects of chelation therapy to control blood lead levels in lead workers, which have recently attracted critical attention. It is of considerable importance to ascertain whether such a therapeutic approach may, under some circumstances, in fact contribute to the deleterious effects of undue lead exposure.

  8. Determination of Trace Platinum, Palladium and Gold in Geochemical Samples by Emission Spectrometry With Lead Fire Assaying Concentration%铅火试金富集-发射光谱法测定化探样品痕量金、铂和钯

    Institute of Scientific and Technical Information of China (English)

    陈春军; 钟宁

    2014-01-01

    试样用铅火试金富集铂组元素及金,加入1 mg银,在950℃熔融得到含贵金属的铅扣。铅扣与熔渣分离后在900℃灰吹得含铂、钯和金的银合金粒。把合金粒装入电极,以发射光谱法同时测定铂、钯和金的含量。%Platinum group elements and gold in sample were enriched by lead fire assaying, after adding 1 mg silver and melting at 950 ℃, lead button containing precious metals was obtained. Then lead button was separated from slag, silver grains containing platinum, palladium and gold were obtained by soot blowing at 900 ℃. Putting the alloy grain into the electrode, contents of platinum, palladium and gold were simultaneously determined by the emission spectrometry.

  9. Lead sorption-desorption from organic residues.

    Science.gov (United States)

    Duarte Zaragoza, Victor M; Carrillo, Rogelio; Gutierrez Castorena, Carmen M

    2011-01-01

    Sorption and desorption are mechanisms involved in the reduction of metal mobility and bioavailability in organic materials. Metal release from substrates is controlled by desorption. The capacity of coffee husk and pulp residues, vermicompost and cow manure to adsorb Pb2+ was evaluated. The mechanisms involved in the sorption process were also studied. Organic materials retained high concentrations of lead (up to 36,000 mg L(-1)); however, the mechanisms of sorption varied according to the characteristics of each material: degree of decomposition, pH, cation exchange capacity and percentage of organic matter. Vermicompost and manure removed 98% of the Pb from solution. Lead precipitated in manure and vermicompost, forming lead oxide (PbO) and lead ferrite (PbFe4O7). Adsorption isotherms did not fit to the typical Freundlich and Langmuir equations. Not only specific and non-specific adsorption was observed, but also precipitation and coprecipitation. Lead desorption from vermicompost and cow manure was less than 2%. For remediation of Pb-polluted sites, the application of vermicompost and manure is recommended in places with alkaline soils because Pb precipitation can be induced, whereas coffee pulp residue is recommended for acidic soils where Pb is adsorbed.

  10. Relationship Between Total and Bioaccessible Lead on Children's Blood Lead Levels in Urban Residential Philadelphia Soils.

    Science.gov (United States)

    Bradham, Karen D; Nelson, Clay M; Kelly, Jack; Pomales, Ana; Scruton, Karen; Dignam, Tim; Misenheimer, John C; Li, Kevin; Obenour, Daniel R; Thomas, David J

    2017-09-05

    Relationships between total soil or bioaccessible lead (Pb), measured using an in vitro bioaccessibility assay, and children's blood lead levels (BLL) were investigated in an urban neighborhood in Philadelphia, PA, with a history of soil Pb contamination. Soil samples from 38 homes were analyzed to determine whether accounting for the bioaccessible Pb fraction improves statistical relationships with children's BLLs. Total soil Pb concentration ranged from 58 to 2821 mg/kg; the bioaccessible Pb concentration ranged from 47 to 2567 mg/kg. Children's BLLs ranged from 0.3 to 9.8 μg/dL. Hierarchical models were used to compare relationships between total or bioaccessible Pb in soil and children's BLLs. Total soil Pb concentration as the predictor accounted for 23% of the variability in child BLL; bioaccessible soil Pb concentration as the predictor accounted for 26% of BLL variability. A bootstrapping analysis confirmed a significant increase in R(2) for the model using bioaccessible soil Pb concentration as the predictor with 99.0% of bootstraps showing a positive increase. Estimated increases of 1.3 μg/dL and 1.5 μg/dL in BLL per 1000 mg/kg Pb in soil were observed for this study area using total and bioaccessible Pb concentrations, respectively. Children's age did not contribute significantly to the prediction of BLLs.

  11. National Geochemical Database: Concentrate

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Geochemistry of concentrates from the National Geochemical Database. Primarily inorganic elemental concentrations, most samples are from the continental US and...

  12. Urine concentration test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003608.htm Urine concentration test To use the sharing features on this page, please enable JavaScript. A urine concentration test measures the ability of the kidneys to ...

  13. Psychological performance of subjects with low exposure to lead

    Energy Technology Data Exchange (ETDEWEB)

    Haenninen, H.; Hernberg, S.; Mantere, P.; Vesanto, R.; Jalkanen, M.

    1978-10-01

    In a study of the effects of low lead exposure on psychological performance, 49 exposed workers and 24 controls were given a psychological test battery. All the lead workers had been under regular monitoring during their entire exposure time, and only workers whose maximal blood lead concentration had never exceeded 70 microgram/100 ml were included in the study. The most important finding was a significant relationship between impaired psychological performance and lead uptake within the exposed group. The performances that were most affected by lead depended on visual intelligence and visual-motor functions. Age and neuroticism did not explain these relationships. Considering that no single blood lead concentration had ever exceeded 70 microgram/100 ml, these findings indicate that the threshold for impaired performance lies below that level.

  14. Nephrotoxic effects of lead nitrate in Rana ridibunda

    Energy Technology Data Exchange (ETDEWEB)

    Loumbourdis, N.S. [Department of Zoology, University of Thessaloniki, 54124, Thessaloniki (Greece)

    2003-09-01

    The impact of lead (Pb) on kidney histopathology of the frog Rana ridibunda was investigated. Female frogs were exposed for 4, 10 and 30 days to 14 ppm lead (as lead nitrate). All the lead concentrations and many histological changes were time dependent. Light microscopy of kidney revealed morphological changes mainly in the proximal convoluted tubule (PCT) cells. The most severe changes such as vacuolation, Perl's stained material, infiltration, brush border destruction and proximal tubule damage were detected in the animals exposed for 10 and 30 days. Karyomegaly was highest at 10-days exposure, probably as a result of intense stress caused by the lead. Some PCT in the 30-days-exposed animals were von Kossa's method positive, suggesting the presence of calcium. The possibility is discussed that some of these changes, such as karyomegaly and intranuclear inclusions, might be preneoplastic if lead was supplied at high concentrations and for long time. (orig.)

  15. Effect of particle size on lead absorption from the gut

    Energy Technology Data Exchange (ETDEWEB)

    Barltrop, D.; Meek, F.

    1979-07-01

    The relationship between particle size and absorption of lead particles from the gastrointestinal tract of the rat has been investigated. Preparations of metallic lead of particle size between 0. and 250..mu.. were incorporated in laboratory rat diets and absorption determined by measurement of tissue lead concentrations attained under standard conditions. An inverse relationship was found between particle size and lead absorption; this relationship was most marked in the 0 to 100..mu.. range. A five-fold enhancement of absorption was observed from the diet with lead particles of mean size 6..mu.., compared with 197..mu.. particle size. Lead absorption from dried paint films containing lead chromate and lead octoate was measured using a similar technique. a marked enhancement of absorption was observed for both paints when particle size was reduced from 500 to 1000..mu.. to < 50..mu...

  16. Heavy Metal Concentrations in Maltese Potable Water

    Directory of Open Access Journals (Sweden)

    Roberta Bugeja

    2015-05-01

    Full Text Available This study evaluates the levels of aluminum (Al, cadmium (Cd, chromium (Cr, copper (Cu, iron (Fe, lead (Pb, nickel (Ni and zinc (Zn in tap water samples of forty localities from around the Maltese Islands together with their corresponding service supply reservoirs. The heavy metal concentrations obtained indicated that concentrations of the elements were generally below the maximum allowed concentration established by the Maltese legislation. In terms of the Maltese and EU water quality regulations, 17.5% of the localities sampled yielded water that failed the acceptance criteria for a single metal in drinking water. Higher concentrations of some metals were observed in samples obtained at the end of the distribution network, when compared to the concentrations at the source. The observed changes in metal concentrations between the localities’ samples and the corresponding supply reservoirs were significant. The higher metal concentrations obtained in the samples from the localities can be attributed to leaching in the distribution network.

  17. When is Concentration Beneficial?

    OpenAIRE

    Liron-Espana, Carmen; Lopez, Rigoberto A.

    2001-01-01

    This paper separates market power and efficiency effects of concentration in a sample of 255 U.S. manufacturing industries and computes welfare changes from rises in concentration. The empirical findings reveal that in nearly two-third of the cases, consumers lose as efficiency gains are generally pocketed by the industries. From an aggregate welfare standpoint, concentration is found to be beneficial in nearly 70% of the cases, mostly for low and moderate levels of concentration being partic...

  18. Photovoltaics. III - Concentrators

    Science.gov (United States)

    Backus, C. E.

    1980-02-01

    Photovoltaic concentration systems that redirect sunlight falling on a surface to a smaller solar-cell surface concentrating the intensity of sunlight many times are examined. It is noted that solar cells for concentrating systems must be designed for low internal resistance as well as for high sunlight intensities. Two designs of silicon cells are presented that perform well at high concentrations; these are interdigitated back-contact cells and vertical multijunction cells. Attention is given to heat tapping of reemitted light.

  19. Port Pirie cohort study: maternal blood lead and pregnancy outcome

    Energy Technology Data Exchange (ETDEWEB)

    McMichael, A.J.; Vimpani, G.V.; Robertson, E.F.; Baghurst, P.A.; Clark, P.D.

    1986-03-01

    During a three-year period, 831 pregnant women in and around Port Pirie, South Australia--a lead smelter community with longstanding lead pollution--were enrolled in a cohort study to examine prospectively the relation between body lead burden and pregnancy outcome. Three-quarters of the enrolled women were residents of the Port Pirie municipality; the other women lived in adjacent towns and countryside. At 14-20 weeks' gestation, the Port Pirie resident women had a mean blood lead concentration of 10.6 micrograms/dl, while the mean in the other (non-Port Pirie) women was 7.6 micrograms/dl. Similar differences were observed in maternal blood samples taken at 30-36 weeks, at delivery, and from the umbilical cord. These blood lead measures, in conjunction with information collected on other risk factors, were then examined in relation to pregnancy outcome. Among 749 pregnancies followed to completion, pre-term delivery was statistically significantly associated, in a dose-response manner, with maternal blood lead concentration at delivery. Mothers of late fetal deaths (stillbirths) had blood lead concentrations at 14-20 weeks' gestation similar to those of all the other women but had lower concentrations at delivery than the other women. Outcomes of pregnancy for which no association with blood lead was detected were spontaneous abortion, low birthweight (for births at term), intrauterine growth retardation, premature rupture of the membranes, and congenital anomalies.

  20. Childhood lead exposure in an enslaved African community in Barbados

    DEFF Research Database (Denmark)

    Schroeder, Hannes; Shuler, Kristrina; Chenery, Simon

    2013-01-01

    a clear association between low (i.e., below 1 ppm) enamel lead concentrations and higher enamel 87Sr/86Sr ratios which have previously been interpreted as being indicative of African birth, suggesting that individuals with low enamel lead levels were indeed born in Africa as opposed to the New World...... the colonial period....

  1. Lead poisoning and trace elements in common eiders from Finland

    Science.gov (United States)

    Hollmén, Tuula E.; Franson, J.C.; Poppenga, R.H.; Hario, Martti; Kilpi, Mikael

    1998-01-01

    We collected carcasses of 52 common eider Somateria mollissima adults and ducklings and blood samples from 11 nesting eider hens in the Gulf of Finland near Helsinki in 1994, 1995 and 1996. Samples of liver tissue were analysed for arsenic, cadmium, chromium, copper, iron, lead, magnesium, manganese, mercury, molybdenum, selenium and zinc. Blood was analysed for lead, mercury and selenium. Most of the 21 adults examined at necropsy were emaciated with empty gizzards, and no ingested shotgun pellets or other metal were found in any of the birds. Three adult females had a combination of lesions and tissue lead residues characteristic of lead poisoning. Two of these birds had acid-fast intranuclear inclusion bodies in renal epithelial cells and high concentrations of lead (73.4 and 73.3 ppm; all liver residues reported on dry weight basis) in their livers. The third was emaciated with a liver lead concentration of 47.9 ppm. An adult male had a liver lead concentration of 81.7 ppm, which is consistent with severe clinical poisoning. Two other adults, one male and one female, had liver lead concentrations of 14.2 and 8.03 ppm, respectively. Lead concentrations in the blood of hens ranged from 0.11 to 0.63 ppm wet weight. Selenium residues of A?60 ppm were found in the livers of five adult males. Selenium concentrations in the blood of hens ranged from 1.18 to 3.39 ppm wet weight. Arsenic concentrations of 27.5-38.5 ppm were detected in the livers of four adult females. Detectable concentrations of selenium, mercury and molybdenum were found more frequently in the livers of adult males arriving on the breeding grounds than in incubating females, while the reverse was true for arsenic, lead and chromium. Mean concentrations of selenium, copper and molybdenum were higher in the livers of arriving males than in the livers of incubating hens, but hens had greater concentrations of iron and magnesium. Concentrations of trace elements were lower in the livers of ducklings than

  2. Rheology of concentrated biomass

    Science.gov (United States)

    J.R. Samaniuk; J. Wang; T.W. Root; C.T. Scott; D.J. Klingenberg

    2011-01-01

    Economic processing of lignocellulosic biomass requires handling the biomass at high solids concentration. This creates challenges because concentrated biomass behaves as a Bingham-like material with large yield stresses. Here we employ torque rheometry to measure the rheological properties of concentrated lignocellulosic biomass (corn stover). Yield stresses obtained...

  3. Lead Tolerance and Accumulation in White Poplar Cultivated In Vitro

    Directory of Open Access Journals (Sweden)

    Branislav Kovačević

    2013-06-01

    Full Text Available Background and Purpose: This paper analyses the lead tolerance and accumulation in white poplar genotypes in vitro, in order to optimize genotype evaluation and other procedures in their implementation in phytoremediation projects and landscaping in areas endangered by lead accumulation. Material and Methods: The lead tolerance and accumulation of five white poplar genotypes after 35 days in vitro cultivation on media supplemented with lead was examined. The following Pb(NO32 concentrations were used: 0, 10-6, 10-5, 10-4 and 10-3 M. Tolerance analysis (described by tolerance indices was based on morphological parameters, biomass accumulation and the content of photosynthetic pigments, while lead accumulation was described by shoot lead accumulation and shoot lead content. Results and Conclusions: The chosen lead concentrations appeared not to be lethal. Moreover, the obtained results showed that the tested lead concentrations had a positive effect on: number of formed roots, shoot moisture content and shoot height. The best differentiation among the examined genotypes was gained by the tolerance index based on the shoot height on 10-4 M Pb(NO32. The shoot lead accumulation and shoot lead content significantly increased on 10-4 and 10-3 M Pb(NO32 media. Thus, the concentration of 10-4 M Pb(NO32 is recommended for further research. Two examined genotypes of horticultural value (LCM and LBM achieved a significantly higher lead shoot content compared to the wide spread genotype “Villafranca” (almost 200% and 125% higher, respectively.

  4. Status of photovoltaic concentrator modules and systems

    Energy Technology Data Exchange (ETDEWEB)

    Maish, A.B.

    1994-04-01

    Several leading line- and point-focus photovoltaic concentrator system development programs are reviewed, including those by ENTECH, SEA Corporation, AMONIX, and Alpha Solarco. Concentrating collectors and trackers are gaining maturity and reaching product status as designs are made more manufacturable and reliable. Utilities are starting to take notice of this emerging technology, and several privately-funded utility installations are underway. Several advantages are offered by concentrators, including low system and capital cost and rapid production ramp-up. These are discussed along with issues generally raised concerning concentrator technology.

  5. Lead Levels in Utah Eagles

    Science.gov (United States)

    Arnold, Michelle

    2006-10-01

    Lead is a health hazard to most animals, causing adverse effects to the nervous and reproductive systems if in sufficient quantity. Found in most fishing jigs and sinkers, as well as some ammunition used in hunting, this metal can poison wildlife such as eagles. Eagles are raptors, or predatory birds, and their lead exposure would most likely comes from their food -- a fish which has swallowed a sinker or lead shot in carrion (dead animal matter). As part of an ongoing project to investigate the environment lead levels in Utah, the bone lead levels in the wing bones of eagles have been measured for eagle carcasses found throughout Utah. The noninvasive technique of x-ray fluorescence was used, consisting of a Cd-109 radioactive source to activate lead atoms and a HPGe detector with digital electronics to collect the gamma spectra. Preliminary results for the eagles measured to date will be presented.

  6. Lead shot contribution to blood lead of First Nations people: The use of lead isotopes to identify the source of exposure

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, Leonard J.S. [Department of Environment and Resource Studies, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada)], E-mail: ljtsuji@fes.uwaterloo.ca; Wainman, Bruce C. [Faculty of Health Sciences, McMaster University, Hamilton, Ontario, L8N 3Z5 (Canada); Martin, Ian D. [Department of Environment and Resource Studies, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Sutherland, Celine [Attawapiskat First Nation Health Services, Attawapiskat, Ontario, P0L 1A0 (Canada); Weber, Jean-Philippe; Dumas, Pierre [Centre de toxicologie, Institut national de sante publique du Quebec, Quebec City, Quebec, G1V 5B3 (Canada); Nieboer, Evert [Faculty of Health Sciences, McMaster University, Hamilton, Ontario, L8N 3Z5 (Canada); Institute of Community Medicine, University of Tromso, Tromso N-9037 (Norway)

    2008-11-01

    Although lead isotope ratios have been used to identify lead ammunition (lead shotshell pellets and bullets) as a source of exposure for First Nations people of Canada, the actual source of lead exposure needs to be further clarified. Whole blood samples for First Nations people of Ontario, Canada, were collected from participants prior to the traditional spring harvest of water birds, as well as post-harvest. Blood-lead levels and stable lead isotope ratios prior to, and after the harvest were determined by ICP-MS. Data were analyzed by paired t-tests and Wilcoxon Signed-Ranks tests. All participants consumed water birds harvested with lead shotshell during the period of study. For the group excluding six males who were potentially exposed to other sources of lead (as revealed through a questionnaire), paired t-tests and Wilcoxon Signed-Ranks tests showed consistent results: significant (p < 0.05) increases in blood-lead concentrations and blood levels of {sup 206}Pb/{sup 204}Pb and {sup 206}Pb/{sup 207}Pb towards the mean values we previously reported for lead shotshell pellets; and a significant decrease in {sup 208}Pb/{sup 206}Pb values towards the mean for lead shotshell pellets. However, when we categorized the group further into a group that did not use firearms and did not eat any other traditional foods harvested with lead ammunition other than waterfowl, our predictions for {sup 206}Pb/{sup 204}Pb, {sup 206}Pb/{sup 207}Pb and {sup 208}Pb/{sup 206}Pb hold true, but there was not a significant increase in blood-lead level after the hunt. It appears that the activity of hunting (i.e., use of a shotgun) was also an important route of lead exposure. The banning of lead shotshell for all game hunting would eliminate a source of environmental lead for all people who use firearms and/or eat wild game.

  7. Taking the Lead : Gender, Social Context and Preference to Lead

    NARCIS (Netherlands)

    Hong, A.P.C.I.; Schaafsma, J.; van der Wijst, P.J.

    2014-01-01

    Previous research has demonstrated that women tend to emerge as leaders less often than men. In the present study, we examined to what extent women's and men's preference to lead is influenced by social context. It was hypothesized that women have a less strong preference to lead than men in a compe

  8. Undue Lead Absorption and Lead Poisoning in Children: An Overview.

    Science.gov (United States)

    Lin-Fu, J. S.

    The toxic effects of lead, a useful metal ubiquitous in the human environment, have long been known. The occupational hazards of lead poisoning were well established by the early 19th century, but plumbism in children caused by paint ingestion was not reported until the turn of the century. Even in 1924, the child was said to live in a "lead…

  9. Manganese incorporation into ferroelectric lead titanate

    Science.gov (United States)

    Stoupin, Stanislav

    Substitution with 3d magnetic transition elements in ABO 3 ferroelectric perovskite host media is widely utilized to produce relaxor ferroelectrics. Many resulting solid solutions exhibit magnetoelectric properties affected by concentration levels of the introduced magnetic ions. For conventional material preparation techniques such as firing of mechanically mixed oxides, incorporation is often limited by 5 mol% concentration level. Doping at higher concentrations requires introduction of other substituents to compensate charge within the unit cell to promote formation of the perovskite phase. In contrast, molecular mixing of precursor materials at the initial phase of preparation procedure offers an advantage of achieving higher incorporation levels of the 3d elements without additional charge-compensating ions. Presented in this thesis is a new sol-gel procedure utilized for high level incorporation of 3d magnetic ions into ferroelectric lead titanate. The technique was applied to produce PbTi1-xMnxO 3 solid solution, a perovskite system promising for high degree of magnetoelectric coupling. Concentration dependent studies were performed to characterize structural, thermal, ferroelectric and magnetic properties of the material. The solubility limit of Mn has been found to be 20 mol% and the material remains tetragonally distorted. X-ray Absorption Spectroscopy confirms that local structural environment of Mn, Ti, and Pb is consistent with tetragonal symmetry of the unit cell. Increase in Mn concentration leads to reduction in melting point, broadening of the ferroelectric transition, reduction of the transition temperature and increase in dielectric constant of the material. At the solubility limit the system was found to be ferromagnetic below 50 K.

  10. Archives of Atmospheric Lead Pollution

    Science.gov (United States)

    Weiss, Dominik; Shotyk, William; Kempf, Oliver

    Environmental archives such as peat bogs, sediments, corals, trees, polar ice, plant material from herbarium collections, and human tissue material have greatly helped to assess both ancient and recent atmospheric lead deposition and its sources on a regional and global scale. In Europe detectable atmospheric lead pollution began as early as 6000years ago due to enhanced soil dust and agricultural activities, as studies of peat bogs reveal. Increased lead emissions during ancient Greek and Roman times have been recorded and identified in many long-term archives such as lake sediments in Sweden, ice cores in Greenland, and peat bogs in Spain, Switzerland, the United Kingdom, and the Netherlands. For the period since the Industrial Revolution, other archives such as corals, trees, and herbarium collections provide similar chronologies of atmospheric lead pollution, with periods of enhanced lead deposition occurring at the turn of the century and since 1950. The main sources have been industry, including coal burning, ferrous and nonferrous smelting, and open waste incineration until c.1950 and leaded gasoline use since 1950. The greatest lead emissions to the atmosphere all over Europe occurred between 1950 and 1980 due to traffic exhaust. A marked drop in atmospheric lead fluxes found in most archives since the 1980s has been attributed to the phasing out of leaded gasoline. The isotope ratios of lead in the various archives show qualitatively similar temporal changes, for example, the immediate response to the introduction and phasing out of leaded gasoline. Isotope studies largely confirm source assessments based on lead emission inventories and allow the contributions of various anthropogenic sources to be calculated.

  11. Teratogen update: lead and pregnancy.

    Science.gov (United States)

    Bellinger, David C

    2005-06-01

    This review focuses on the impacts of lead exposure on reproductive health and outcomes. High levels of paternal lead exposure (>40 microg/dl or >25 microg/dl for a period of years) appear to reduce fertility and to increase the risks of spontaneous abortion and reduced fetal growth (preterm delivery, low birth weight). Maternal blood lead levels of approximately 10 microg/dl have been linked to increased risks of pregnancy hypertension, spontaneous abortion, and reduced offspring neurobehavioral development. Somewhat higher maternal lead levels have been linked to reduced fetal growth. Some studies suggest a link between increased parental lead exposure and congenital malformations, although considerable uncertainty remains regarding the specific malformations and the dose-response relationships. Common methodological weaknesses of studies include potential exposure misclassifications due to the frequent unavailability of exposure biomarker measurements at biologically appropriate times and uncertainty regarding the best exposure biomarker(s) for the various outcomes. A special concern with regard to the pregnant woman is the possibility that a fetus might be exposed to lead mobilized from bone stores as a result of pregnancy-related metabolic changes, making fetal lead exposure the result of exposure to exogenous lead during pregnancy and exposure to endogenous lead accumulated by the woman prior to pregnancy. By reducing bone resorption, increased calcium intake during the second half of pregnancy might reduce the mobilization of lead from bone compartments, even at low blood lead levels. Subgroups of women who incurred substantial exposures to lead prior to pregnancy should be considered to be at increased risk.

  12. Recovery of indium and lead from lead bullion

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Lead and indium were recovered by electrolysis and nonequilibrium solvent extraction process from lead bullion.The effects of current density,electrolytic period and circle amnant of electrolyte on the electrochemical dissolution of lead and indium were investigated.The effects of extraction phase ratio and mixing time on solvent extraction of indium and striping phase ratio and stripping stage on the loaded organic phase stripping were also investigated.The experimental results indicate that under optimum conditions,the purity of lead deposited on cathode is 98.5% and the deposit rate of lead is 99.9%,the dissolution rate of indium is 94.28%,the extraction rate of indium is 98.69%,the stripping rate of indium is almost 100%,and the impurity elements,such as Zn,Fe and Sn can be removed.

  13. Safe Leads and Lead Changes in Competitive Team Sports

    CERN Document Server

    Clauset, A; Redner, S

    2015-01-01

    We investigate the time evolution of lead changes within individual games of competitive team sports. Exploiting ideas from the theory of random walks, the number of lead changes within a single game follows a Gaussian distribution. We show that the probability that the last lead change and the time of the largest lead size are governed by the same arcsine law, a bimodal distribution that diverges at the start and at the end of the game. We also determine the probability that a given lead is "safe" as a function of its size $L$ and game time $t$. Our predictions generally agree with comprehensive data on more than 1.25 million scoring events in roughly 40,000 games across four professional or semi-professional team sports, and are more accurate than popular heuristics currently used in sports analytics.

  14. Lead Poisoning in Wild Birds

    Science.gov (United States)

    Lahner, Lesanna L.; Franson, J. Christian

    2009-01-01

    Lead in its various forms has been used for thousands of years, originally in cooking utensils and glazes and more recently in many industrial and commercial applications. However, lead is a potent, potentially deadly toxin that damages many organs in the body and can affect all animals, including humans. By the mid 1990s, lead had been removed from many products in the United States, such as paint and fuel, but it is still commonly used in ammunition for hunting upland game birds, small mammals, and large game animals, as well as in fishing tackle. Wild birds, such as mourning doves, bald eagles, California condors, and loons, can die from the ingestion of one lead shot, bullet fragment, or sinker. According to a recent study on loon mortality, nearly half of adult loons found sick or dead during the breeding season in New England were diagnosed with confirmed or suspected lead poisoning from ingestion of lead fishing weights. Recent regulations in some states have restricted the use of lead ammunition on certain upland game hunting areas, as well as lead fishing tackle in areas frequented by common loons and trumpeter swans. A variety of alternatives to lead are available for use in hunting, shooting sports, and fishing activities.

  15. Lead removal by Spirulina platensis biomass.

    Science.gov (United States)

    Al-Homaidan, Ali A; Al-Abbad, Aljawharah F; Al-Hazzani, Amal A; Al-Ghanayem, Abdullah A; Alabdullatif, Jamila A

    2016-01-01

    In this investigation, we report on the biosorption of Pb (II) from aqueous solutions by the nonliving biomass of the micro-alga (cyanobacterium) Spirulina platensis. Propagation of the micro-alga was carried out in outside oblong raceway ponds. The biomass was cleaned, dried and used for the investigation. The effects of pH, adsorbent dose, temperature, initial concentration of Pb (II), and contact time on the adsorption of lead by the dry biomass were studied. The experiments were carried out in 250 ml conical flasks containing 100 ml of test solutions using an orbital incubator at 150 rpm. Concentrations of the metal before and after the experiments were measured using Atomic Absorption Spectrophotometer. Very high levels of Pb (II) removal (>91%) were obtained. The optimum conditions for maximal adsorption by S. platensis were found to be pH 3; 2 g of adsorbent dose; incubation at 26°C; 100 mg/l of lead initial concentration and 60 minutes of contact time. The experimental data fitted well with Freundlich isotherm equation with R(2) values greater than 0.97. Based on our results, we recommend the utilization of S. platensis biomass for heavy metal removal from aqueous solutions.

  16. [Use of urine lead level as an exposure indicator and its relationship to blood lead].

    Science.gov (United States)

    Moreira, Maria de Fátima Ramos; Neves, Eduardo Borba

    2008-09-01

    The aim of this work was to verify whether there are statistically significant correlation between the concentrations of lead in blood (Pb-B) and urine (Pb-U). Electrothermal atomic absorption spectrometry was used in the determination of lead concentration in biological material. Venous blood and spot urine were collected from workers occupationally exposed (95), adults (130) and children up to 15 years old (22) environmentally exposed. After a test showing significant differences between Pb-U and the three categories previously determined, cutting points for Pb-U were established to predict Pb-B values by the ROC curve. Thus, it is expected that Pb-B is lower than 10 microg.dL-(1) with Pb-U up to 0.55 microg.dL-(1), whereas lead levels in blood below 27.6 microg.dL-(1) are expected when the amount of the metal in urine is lower than 2.05 microg.dL-(1). So, urine can be used to replace blood for the assessment of the occupational exposure to lead. However, caution is advised in the case of environmental exposure, since urinary lead should be used just as an estimation of the metal content in blood.

  17. [Lead uptake by plant in soil-plant system at lead-zinc deposit area of western Hunan province].

    Science.gov (United States)

    Li, Yong-Hua; Yang, Lin-Sheng; Ji, Yan-Fang; Sun, Hong-Fei; Li, Hai-Rong; Wang, Wu-Yi

    2008-01-01

    Contents of lead in several crops as well as its uptake and distribution by paddy in typical lead-zinc deposit area of western Hunan province were studied based on field systematic sampling and laboratory analysis. The average concentration of lead in rice, maize and soy bean in the deposit was 2.4, 1.2 and 3.3 times higher than that in control area, respectively, suggesting that crops in the deposit were heavily contaminated by the element. Significant difference of the lead concentrations in crops was found among different crop species and different organs of the same crops. The average concentration of lead followed the trend: soy bean > rice > maize (among crop species), and root > haulm > seed (among organs). Paddy root exhibited strong binding and tolerant capacity to lead. Correlation analysis indicated that soil lead was main retention in paddy root, whereas the gaseous lead might be the main source for lead in the aerial part of crop. Heavy metals such as Hg, Cd as well as Pb co-enriched in crops, therefore the mechanism and health risk of the combined pollution of heavy metals in the deposit crops should be paid attention to.

  18. Lead shot contribution to blood lead of First Nations people: the use of lead isotopes to identify the source of exposure.

    Science.gov (United States)

    Tsuji, Leonard J S; Wainman, Bruce C; Martin, Ian D; Sutherland, Celine; Weber, Jean-Philippe; Dumas, Pierre; Nieboer, Evert

    2008-11-01

    Although lead isotope ratios have been used to identify lead ammunition (lead shotshell pellets and bullets) as a source of exposure for First Nations people of Canada, the actual source of lead exposure needs to be further clarified. Whole blood samples for First Nations people of Ontario, Canada, were collected from participants prior to the traditional spring harvest of water birds, as well as post-harvest. Blood-lead levels and stable lead isotope ratios prior to, and after the harvest were determined by ICP-MS. Data were analyzed by paired t-tests and Wilcoxon Signed-Ranks tests. All participants consumed water birds harvested with lead shotshell during the period of study. For the group excluding six males who were potentially exposed to other sources of lead (as revealed through a questionnaire), paired t-tests and Wilcoxon Signed-Ranks tests showed consistent results: significant (plead concentrations and blood levels of (206)Pb/(204)Pb and (206)Pb/(207)Pb towards the mean values we previously reported for lead shotshell pellets; and a significant decrease in (208)Pb/(206)Pb values towards the mean for lead shotshell pellets. However, when we categorized the group further into a group that did not use firearms and did not eat any other traditional foods harvested with lead ammunition other than waterfowl, our predictions for (206)Pb/(204)Pb, (206)Pb/(207)Pb and (208)Pb/(206)Pb hold true, but there was not a significant increase in blood-lead level after the hunt. It appears that the activity of hunting (i.e., use of a shotgun) was also an important route of lead exposure. The banning of lead shotshell for all game hunting would eliminate a source of environmental lead for all people who use firearms and/or eat wild game.

  19. Lead-free primary explosives

    Science.gov (United States)

    Huynh, My Hang V.

    2010-06-22

    Lead-free primary explosives of the formula (cat).sub.Y[M.sup.II(T).sub.X(H.sub.2O).sub.6-X].sub.Z, where T is 5-nitrotetrazolate, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

  20. Leading change: a concept analysis.

    Science.gov (United States)

    Nelson-Brantley, Heather V; Ford, Debra J

    2017-04-01

    To report an analysis of the concept of leading change. Nurses have been called to lead change to advance the health of individuals, populations, and systems. Conceptual clarity about leading change in the context of nursing and healthcare systems provides an empirical direction for future research and theory development that can advance the science of leadership studies in nursing. Concept analysis. CINAHL, PubMed, PsycINFO, Psychology and Behavioral Sciences Collection, Health Business Elite and Business Source Premier databases were searched using the terms: leading change, transformation, reform, leadership and change. Literature published in English from 2001 - 2015 in the fields of nursing, medicine, organizational studies, business, education, psychology or sociology were included. Walker and Avant's method was used to identify descriptions, antecedents, consequences and empirical referents of the concept. Model, related and contrary cases were developed. Five defining attributes of leading change were identified: (a) individual and collective leadership; (b) operational support; (c) fostering relationships; (d) organizational learning; and (e) balance. Antecedents were external or internal driving forces and organizational readiness. The consequences of leading change included improved organizational performance and outcomes and new organizational culture and values. A theoretical definition and conceptual model of leading change were developed. Future studies that use and test the model may contribute to the refinement of a middle-range theory to advance nursing leadership research and education. From this, empirically derived interventions that prepare and enable nurses to lead change to advance health may be realized. © 2016 John Wiley & Sons Ltd.

  1. Experience with intravascular lead extraction

    Institute of Scientific and Technical Information of China (English)

    MA Jian; TANG Kai; WANG Fang-zheng; ZHANG Shu; HUANG Cong-xin

    2005-01-01

    @@ With the increase of clinical use of cardiac pacemaker, a certain kinds of severe leads-related complications (especially infection) have presented in a few patients who underwent pacemaker implantation. The best way to manage this problem is to remove the transvenous leads.1,2 The technique for percutaneous removal of transvenous leads have undergone considerable development in western countries over the past 2 decades. However, there was scarce data on the application of this technique in China. This article reports the results of transvenous extraction of 171 permanent pacemaker leads with the standard lead extraction devices and intravascular countertraction technique during the period from January 1996 to May 2005 in the Center of Arrhythmia Diagnosis and Treatment, Fu Wai Hospital, Beijing, China.

  2. Assessment of soil lead exposure in children in Shenyang, China.

    Science.gov (United States)

    Ren, H M; Wang, J D; Zhang, X L

    2006-11-01

    Soil lead pollution is serious in Shenyang, China. The paper brings together the soil work, the bioaccessibility, and the blood lead data to assess the soil lead exposure in children in Shenyang, China. Approximately 15.25% of the samples were above China Environment Protection Agency guideline concentration for soil Pb to protect human from health risk (350 mgkg(-1)). Pb concentrations varied among use scenarios. The main lead contamination sources are industry emission and automobile exhaust. Bioaccessibility also varied among use scenarios. Children, who ingested soil from industrial area, public parks, kindergarten playground, and commercial area, are more susceptible to soil lead toxicity. The industrial area soil samples presented higher bioaccessibility compared to the other use scenario soil samples contaminated by automobile exhaust. The result also suggested a most significant linear relationship between the level of Pb contamination and the amount of Pb mobilized from soil into ingestion juice. Soil pH seemed to have insignificant influence on bioaccessibility in the present study. Bioaccessibility was mainly controlled by other factors that are not investigated in this study. A linear relationship between children blood lead and soil intestinal bioaccessibility was present in the study. Children who are 4-5 years old are more likely to demonstrate the significant relationship between soil lead bioaccessibility and blood lead as their behaviors place them at greatest risk of soil lead toxicity, and their blood lead levels are more likely to represent recent exposure.

  3. Lead dodecanoate coatings for the protection of lead and lead-tin alloy artifacts: Two examples

    Science.gov (United States)

    De Keersmaecker, Michel; Verbeken, Kim; Adriaens, Annemie

    2014-02-01

    In order to understand the corrosive and morphological characteristics of lead dodecanoate protective coatings on real samples, three pipe organ samples were studied using optical microscopy (OM), scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and electrochemical impedance spectroscopy (EIS). The corrosion products and elemental composition of the top layer of the different pipe organ samples were investigated. The results indicate that the three pipe organ samples are made of an alloy composed mainly of lead and tin. After immersion and the deposition of the protective coating, only lead and no tin is detected, which indicates the formation of a thick coating containing lead dodecanoate complexes.

  4. Spectrochemical determination of lead in wines

    Directory of Open Access Journals (Sweden)

    DRAGAN MARKOVIC

    2000-06-01

    Full Text Available The determination of lead in wines of different origin was performed by means of atomic emission spectroscopy with argon stabilized DC. U-shaped arc and electrothermal atomic absorption spectrometry. The comparison of the results obtained by the direct and standard addition method has indicated the presence of a depressive effect of the complex organic matrix. The effect is avoided successfully by mineralization, as well as by dissolution of the samples. Thus, a relative simple but precise and sensitive method involving the application of a stabilized arc and photoelectric detection with time integration of the emission signals is recommended for the determination of low concentrations of lead in wines. The complex organic matrix was investigated by recording the IR spectra of different wine fractions.

  5. Optimization of high-temperature superconductor current leads

    Science.gov (United States)

    Seol, S. Y.; Hull, J. R.; Chyu, M.