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Bacteria interact with a multitude of other organisms, many of which produce antimicrobials. Selection for resistance to these antimicrobials has the potential to result in resistance to clinical antibiotics when active compounds target the same bacterial pathways. The possibility of such cross‐resistance between natural antimicrobials and antibiotics has to our knowledge received very little attention. The antimicrobial activity of extracts from seaweeds, known to be prolific producers of antimicrobials, is here tested against Staphylococcus aureus isolates with varied clinical antibiotic resistance profiles. An overall effect consistent with cross‐resistance is demonstrated, with multidrug‐resistant S. aureus strains being on average more resistant to seaweed extracts. This pattern could potentially indicate that evolution of resistance to antimicrobials in the natural environment could lead to resistance against clinical antibiotics. However, patterns of antimicrobial activity of individual seaweed extracts vary considerably and include collateral sensitivity, where increased resistance to a particular antibiotic is associated with decreased resistance to a particular seaweed extract. Our correlation‐based methods allow the identification of antimicrobial extracts bearing most promise for downstream active compound identification and pharmacological testing. [ABSTRACT FROM AUTHOR]

Abstract: Alternation layered lake sediment that had accumulated over a period of 22 years, from 1990 to 2012, was collected from the Tamagawa Dam Lake, which is located in the northeastern part of Akita Prefecture. The lake water is acidified (pH = 4.1) by the inflow of high‐acidic thermal water (pH = 1.2) from the Obuki Hot Spring, the main hot spring in the Tamagawa Hot Spring area. The vertical variations in Si, Al, Fe, Ti, and Pb contents of the sediment were determined by XRF, EPMA, and LA‐ICP‐MS in order to clarify the sedimentation processes of the lake sediment. The layers consisting of the sediment could be mostly classified into three types: dark brown, yellowish brown, and reddish layers. The contents of Si, Al, Fe, and Ti corresponded to the variation in color of each layer in the sample. Based on the Si, Al, and Fe contents in the sediment of Tamagawa Dam Lake, the sources of these elements were classified as detrital origin in dark brown and yellowish brown layers (Si, Al, and Ti) and chemical precipitate origin in reddish layers (Fe). Detrital components were derived from volcanic rocks in the watershed of Tamagawa Dam Lake. The variation of Pb content did not accord with the color of layers. The content of Pb in the sediment of Tamagawa Dam Lake ranges from 45 to 522 ppm. The vertical variation of Pb content in sediment corresponded to the temporal variation of Pb content in thermal water from the Obuki Hot Spring from 1990 to 2012. A large influence of hydrothermal activity of the Tamagawa Hot Spring on the vertical distribution of Pb was found during the active period of the Obuki Hot Spring, resulting in high Pb content within layers at 5–8 cm from the bottom of the sample. T‐Fe2O3‐rich reddish layers were also found in this range. Therefore, it is assumed that T‐Fe2O3 and Pb originated from Obuki Hot Spring and precipitated in Tamagawa Dam Lake. However, no correlation was found between T‐Fe2O3 and Pb contents for any of the dark brown, yellowish brown, and reddish layers. Some layers with high Pb content were also found to have high SiO2 and Al2O3 contents. These findings indicate that there are several possibilities for the sedimentation process of Pb. The sedimentation of Pb as well as that of T‐Fe2O3 in Tamagawa Dam Lake provides a good example of the accumulation of elements by chemical precipitation away from the source of elements. [ABSTRACT FROM AUTHOR]

Abstract: Several cases have been described in the literature where different ligands enhanced lead (Pb) bioavailability over what would have been expected on the basis of equilibrium models such as the biotic ligand model (BLM). These exceptions compromise the development of BLMs for this metal, and mechanistic knowledge of the involved processes is still insufficient. The present study shows that the hydrophilic organic ligand citrate enhances Pb internalization by Chlamydomonas reinhardtii for both the wild and the wall‐less strains. Despite the high Pb internalization fluxes shown by this alga, which may be near the limits set by diffusion through the boundary layer, and its capacity to assimilate citrate (and potentially Pb‐citrate complexes), neither of these mechanisms could quantitatively account for the observed increase in Pb internalization in the presence of this ligand. However, algal‐driven pH increases in the boundary layer and concomitant changes in Pb speciation successfully explained the observed results. This study suggests that information on bulk solution chemistry is not enough to predict metal bioavailability for organisms that can substantially modify the chemical composition of their boundary layer, as observed for C. reinhardtii. [ABSTRACT FROM AUTHOR]

Kaolinite was utilized as in-furnace sorbent to control submicron lead (Pb) and cadmium (Cd) emissions during waste incineration in a fluidized bed furnace. The secondary combustion chamber temperature ranged from 850 to 1000 °C. The metal capture was investigated for aspects of chemical reaction, physical conglutination and control performance of submicron metal emission. Pb reacted with kaolinite and caused conglutination of nanoscale metal particles at a lower temperature than Cd. Emission control of submicron Pb was far more effective than that of submicron Cd, particularly below 950 °C. For both Pb and Cd, there was capture limitation and an increase of kaolinite fraction above 3% could not further reduce the submicron metal emission. According to toxicity factors (5 Pb = 1 Cd) and the leaching fraction of submicron particles, the comprehensive performance of kaolinite was evaluated and numerous contradictory results were obtained. [ABSTRACT FROM AUTHOR]

The present study investigated the effect of bioturbation by the oligochaete worm Lumbriculus variegatus on the transport and environmental distribution of lead (Pb). Experiments used L. variegatus at densities of 0 ind./m2, 2093 ind./m2, and 8372 ind./m2, in freshwater microcosms with Pb-spiked sediment. At the end of the 14-d experiment, Pb levels in the water column, tissues of L. variegatus, and sediment were determined, and bioturbation was quantified using luminophores. The bioturbation by L. variegatus increased Pb transport from the sediment to the water column. However, it did not significantly affect Pb bioaccumulation by L. variegatus or Pb levels in the sediment. The biodiffusion coefficient ( Db) was positively related to worm density, but did not differ between Pb-spiked sediment and uncontaminated sediment. The latter finding suggests that Pb at the 100 μg/g concentration used in the present study did not affect L. variegatus bioturbation. The present study shows that bioturbation can enhance Pb transfer across the sediment-water interface and thus enhance Pb availability to organisms in the water column. Environ Toxicol Chem 2016;35:1123-1129. © 2015 SETAC [ABSTRACT FROM AUTHOR]

Many communities depend on Lake St. Clair for drinking water and recreational uses. In addition, it is an important transport route for natural resources and manufactured products. The St. Clair River, which flows into the lake from the northeast, is a major source of sediment. The upstream area is known as 'chemical valley' due to a large amount of industrial activity located along the river. Sediment sampling surveys were conducted in 1970, 1974, and 2001 by Environment Canada as part of a continuing monitoring program. Two approaches to the representation, analysis, and visualization of lead contamination were used: a two-dimensional Geographic Information System-based approach using kriging and a three-dimensional approach that utilized the interpolated kriging surfaces overlaid on bathymetry data. The results of combining this analytical method with a three-dimensional representation appear to show that Lake St. Clair generally has lower levels of sediment contamination away from the main flow and circulation patterns leading to its Detroit River outlet. Lead levels declined below the threshold effect level in 2001 compared with the higher concentrations seen in 1970 and 1974. In addition, lake-wide spatial distributions are better visualized using the kriging spatial interpolation results when they are overlaid on the bathymetry data. L'emploi d'outils de géovisualisation pour évaluer la contamination par le plomb des sédiments dans le lac Sainte-Claire De nombreuses communautés utilisent les eaux du lac Sainte-Claire à des fins d'approvisionnement (eau potable) et récréatives. De même, il sert d'axe principal pour le transport des ressources naturelles et des produits transformés. La rivière Sainte-Claire, qui se jette dans le lac depuis le nord-est, déverse d'importantes quantités de sédiments. La zone située en amont abonde de produits chimiques en raison des nombreuses activités industrielles en opération de part et d'autre de la rivière. Des échantillons de sédiments ont été prélevés par Environnement Canada en 1970, 1974 et 2001 dans le cadre d'un programme de surveillance continue. Deux démarches ont été mises en œuvre en vue de représenter, analyser et visualiser la contamination par le plomb : une première s'appuie sur un système d'information géographique à deux dimensions utilisant une modélisation par krigeage, et une seconde à trois dimensions utilisant les surfaces d'interpolation obtenue par krigeage superposées aux données bathymétriques. Cette méthode d'analyse conjuguée avec une représentation en trois dimensions permet d'observer une diminution générale du degré de contamination sédimentaire du lac Sainte-Claire en retrait du courant du chenal principal menant à la décharge de la rivière Détroit. En 2001, les concentrations de plomb ont baissé au-dessous du niveau de l'effet de seuil par rapport aux valeurs plus élevées observées en 1970 et 1974. En outre, une meilleure visualisation des répartitions spatiales du plan d'eau est obtenue grâce aux résultats tirés de l'interpolation spatiale par krigeage lorsque ceux-ci sont superposés aux données bathymétriques. [ABSTRACT FROM AUTHOR]

This study aims at verifying the feasibility of the analysis of particulate matter samples collected with hourly time resolution by a Streaker sampler device, using cheaper and more affordable instrumentations like energy dispersive X-ray fluorescence (ED-XRF) spectrometers. The 'hourly' samples are not analysable with the available commercial laboratory ED-XRF spectrometers, because the aerosol deposit forms a continuous streak that has to be analysed 'point-by-point' with a collimated beam of a few mm size. For this specific application, a custom-made compact XRF spectrometer, designed at the INFN LABEC laboratory in Florence and typically used for in-situ analysis of cultural heritage, has been used. This ED-XRF system is based on the combined use of two X-ray tubes with different anodes (Mo and Ti), a 30-mm2 silicon drift detector and a helium flow to reduce the attenuation of low energy X-rays. A set of elemental thin standards containing elements from Na to Pb has been analysed in order to determine the best experimental conditions, the sensitivity and the detection limits of this system. The results of quantitative analysis on certified aerosol samples, on particulate matter samples collected for 24 h by a low volume sampler and on Streaker samples ('fine' fraction, PM2.5) are in good agreement with those obtained by PIXE and polarized optics ED-XRF measurements. This study demonstrates that a specialized custom-made ED-XRF system may represent a promising solution for elemental analysis of Streaker samples, even for low-Z elements, although PIXE technique still remains unrivalled as regards sensitivity and measurement throughput. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT Lead pollution has increased over the past four centuries with industrialisation, urbanisation, and the use of motor vehicles. In Japan, lead concentrations in human bones of the Edo period (AD 1603-1867) from urban areas were found to be higher than those from suburban areas. Because most wild geese breed in the subarctic zone and winter in the temperate zone, it is to be expected that lead concentrations in archaeological goose bones from domestic individuals would be higher than those from wild individuals because of the difference in their life cycle. In this study, we measured and compared lead concentrations in bones of geese, other birds (duck, chicken, heron, and crow), mammals (dog, cat, pig/wild boar, and deer), and in a human tooth, all from the Kenmin-kan Atochi site, Japan (Edo period). We found that lead pollution affected not only humans but also animals and that environmental lead pollution was widespread in the town. One of the goose bones analysed, a broken and healed ulna, showed a lead concentration approximately twice as high as the other goose bones. In addition, the lead concentration in a duck bone was much higher than in those of wild birds or mammals, which suggests that the duck had lived in an urban environment for a long time. The results suggest that analysis of lead concentrations can detect potential domestic animals that were exposed to environmental lead pollution, such as in the Roman period in Europe and in the Edo period in Japan. By accumulating comparative studies, the analysis of lead concentrations in archaeological goose bones is expected to become a reliable indicator of domestic geese under conditions of environmental lead contamination. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Lead (Pb) has become one of the most abundant heavy metal pollutants of the environment. With its large biomass, maize could be an important object for studying the phytoremediation of Pb-contaminated soil. In our previous research, we screened 19 inbred lines of maize for Pb concentration, and line 178 was identified to be a hyperaccumulator for Pb in both the roots and aboveground parts. To identify important genes and metabolic pathways related to Pb accumulation and tolerance, line 178 was underwent genome expression profile under Pb stress and a control (CK). A total of approximately 11 million cDNA tags were sequenced and 4 665 539 and 4 936 038 clean tags were obtained from the libraries of the test and CK, respectively. In comparison to CK, 2379 and 1832 genes were identified up- or downregulated, respectively, more than fivefolds under Pb stress. Interestingly, all the genes were related to cellular processes and signaling, information storage and processing or metabolism functions. Particularly, the genes involved in posttranslational modification, protein turnover and chaperones; signal transduction, carbohydrate transport and metabolism; and lipid transport and metabolism significantly changed under the treatment. In addition, seven pathways including ribosome, photosynthesis, and carbon fixation were affected significantly, with 118, 12, 34, 21, 18, 72 and 43 differentially expressed genes involved. The significant upregulation of the ribosome pathway may reveal an important secret for Pb tolerance of line 178. And the sharp increase of laccase transcripts and metal ion transporters were suggested to account in part for Pb hyperaccumulation in the line. [ABSTRACT FROM AUTHOR]

Ingestion of lead rifle bullet fragments found in discarded hunter-harvested ungulate gut piles negatively affects avian wildlife. Some large carnivores, such as grizzly bears, are also known to target these gut piles as a food source and are therefore potentially at risk of lead exposure. We investigated whether large carnivores in the greater Yellowstone ecosystem were exposed to lead, and if so, if ammunition ingested from gut piles was an apparent source of exposure. Grizzly bears ( Ursus arctos, n = 82) exhibited higher blood lead levels (median = 4.4 µg/dL, range 1.1-18.6 µg/dL) than black bears ( Ursus americanus, n = 35, median = 1.6, range 0.5-6.9 µg/dL), but blood lead levels did not increase during the autumn hunting season when potentially lead-tainted gut piles are available. Wolves ( Canis lupus, n = 21) and cougars ( Puma concolor, n = 8) showed lead concentrations near or below the minimum level of detection in both blood and tissue samples. Unlike findings in previous studies on avian scavengers, we did not find lead ammunition fragments to be a widespread source of lead exposure in large carnivores. Grizzly bears do, however, exhibit blood lead levels that are higher than what is considered safe in humans, but the source of this exposure remains unknown. © 2011 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Adsorption of lead(II) from water on carbon nanotubes (CNTs) was investigated using a series of batch adsorption experiments. The adsorption rate Was studied experimentally at various temperatures, contact times, and initial pH and lead(II) concentrations. It was observed that a considerable amount of lead(II) was adsorbed during the first 5 minutes of contact time. The pH of the solution strongly influenced the amount of adsorption, and the best results were obtained when pH value was approximately 6. For the adsorption isotherm, the experimental data were analyzed by three two-parameter isotherms (Langmuir, Freundlich, and Temkin) and four three-parameter isotherms (Redhich-Peterson, Sips, Toth, and Khan). The three kinetic models used to test the experimental data were Lagergren first-order, second-order, and the Elovich equation. The results obtained from the study of the thermodynamic parameters showed that the adsorption of lead(II) onto CNTs was a spontaneous and endothermic process. [ABSTRACT FROM AUTHOR]

Soil properties that mitigate hazardous effects of environmental contaminants through soil chemical sequestration should be considered when evaluating ecological risk from terrestrial contamination. The objective of this research was to identify predominant soil chemical/physical properties that modify phytoaccumulation of As, Cd, Pb, and Zn to the non-hyperaccumulating higher plants: Alfalfa (Medicago sativa L.), perennial ryegrass (Lolium perenne L.), and Japanese millet (Echinochloa crusgalli L.). Transmission coefficients were estimated from a dose-response experiment with the use of aboveground tissue contaminant concentrations and correlated with selected soil property measurements to develop statistical prediction models for soil-specific adjustments to ecological risk assessments. Significant correlations between soil properties and transmission coefficients were observed for all four contaminants. Intercorrelation was also observed among soil properties, including cation exchange capacity (CEC) and soil pH (p = 0.035), CEC and total clay (p = 0.030), organic carbon (OC) and total clay content (p = 0.085), reactive iron oxides (FeOX) and OC (p = 0.078), and reactive Mn oxide (MnOX) and total clay content (p < 0.001). Ridge regression, a technique that suppresses the effects of multicollinearity and enables prediction, was used to assess the marginal contributions of soil properties found to mitigate phytoaccumulation. Prediction models were developed for all four contaminants. Significant variables were FeOX for As or pH, OC, CEC, clay content, or a combination of factors for cationic metal models. Ridge regression provides a powerful alternative to conventional multiple regression techniques for ecotoxicological studies when intercorrelated predictors are experimentally unavoidable, as with soil properties. [ABSTRACT FROM AUTHOR]

We present a summary of the technical review, jointly requested by the American Fisheries Society and The Wildlife Society, addressing the hazards to wildlife resulting from lead objects or fragments introduced into aquatic and terrestrial environments from the use of ammunition and fishing tackle. Impacts from lead are well documented in humans, as well as in terrestrial and aquatic organisms. Concern about impacts from lead ammunition and fishing tackle has resulted in the development of non-lead alternatives, educational campaigns, and regulations to restrict their use. This article discusses the general biological impacts of lead exposure from fishing and shooting activities to fish, wildlife, and humans; summarizes existing and proposed regulations to reduce lead exposure to biota; reviews alternatives to lead materials that are currently available for fishing; and outlines options for further actions to reduce wildlife and human exposure to lead from fishing activities. [ABSTRACT FROM AUTHOR]

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 < 0.05) with 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. [ABSTRACT FROM AUTHOR]

A lead monitoring project was established in 1996 to monitor the environmental and health effects of lead being transported through a remote town in tarpaulin-covered trucks. Dust samples from sites on the transport route were collected at 3–6 monthly intervals between 1996 and 1999. Annual blood lead testing clinics, offering voluntary testing to children, were conducted from 1997 to 1999. Of the 55 dust samples analysed, only nine contained particles of lead concentrate and these were present at very low levels. During the project 167 children were tested. The geometic mean of blood lead levels in 1997, 1998 and 1999 were 4.5 µg/dL, 5.0 µg/dL and 5.1 µg/dL, respectively (all within the normal range). Residence on the transport route was not associated with higher lead levels (P > 0.05). Lead transport was not associated with any detectable environmental contamination or increase in children's blood lead levels. [ABSTRACT FROM AUTHOR]

Examines two types of deep tillage as possible management options for reducing lead pellet densities in wetlands in the Sacramento National Wildlife Refuge in California. Vegetation changes that resulted from tilling; Pellet density and depth; Effects of tillage on lead pellets.

This article investigates technological opportunities to close technospheric flows in a large-scale use of a toxic and scarce metal, lead. It analyzes the lead flows and losses to the environment in a modeled lead-acid battery system for Sweden. The modeled system is built on today's technology for production and recycling of lead and batteries while the recovery of used batteries is varied. The analysis shows that the losses from the production and recycling processes are so low that consumption losses and the recovery rate dominate the total system losses. In a steady state with very high recovery of used batteries, the system losses are small compared to natural lead flows and to the historical lead losses during the industrialization. The modeling assumes that all the secondary lead goes back into the production of new batteries even though in Swedish battery manufacturing today, primary lead dominates the lead supply for lead oxide production. The possibilities for increased secondary lead use in the production of lead oxide are also discussed. [ABSTRACT FROM AUTHOR]

The article presents two new resource policy statements namely "Lead in Sport Fishing Tackle" and Climate Change in North American Fisheries" before they are deliberated by American Fisheries Societies (AFS) members during the Annual Meeting on September 14, 2010 in Pittsburgh, Pennsylvania. The first policy proposes measures and initiatives to address the impacts of lead components in sport fishing tackle. The second addresses the need to understand the impact of climate change in North American Fisheries and mitigate, if needed, its adverse effects.

MgO microrods with hierarchical porous structure (ranging from micropores to meso- and macropores) and well-defined rod-like morphology are prepared via a flux (NaCl) and surfactant (nonylphenol polyoxyethylene ether, NP-9) directed thermal decomposition (porcelain boat, 650, 2 h) of hydrothermally grown MgC2O4·2H2O microrods (autoclave, 180 °C, 3 h). [ABSTRACT FROM AUTHOR]

The policy statement of the American Fisheries Society (AFS) about lead in sport fishing tackle adopted in October 2012 is presented. An overview of the negative effects of lead on the environment is provided. It emphasizes the need for scientifically regorous research that will collect toxicological and environmental chemistry data on lead tackle.

The article focuses on a joint technical report by the Wildlife Society and the American Fisheries Society (AFS) concerning the potential hazards of lead brought into the environment via recreational hunting, shooting sports and fishing. It discusses how such sports pose a risk to biological systems as they deposit lead into environment. It stresses that lead stands as a nonessential heavy metal that has no known benefit or function in biological systems. The report also covers the creation of policies for the use of lead in such sports.