Variations In Metal Concentrations Research Articles

Analysis of Moss and Topsoil to Monitor Metal Emissions from a Pulp and Paper Mill in Western Kenya

The mean concentrations of Zn, Cu, Cd, Cr and Fe in mosses around Webuye Pan Paper factory were found to be significantly higher than in controls taken from Kakamega, indicating atmospheric contribution from the anthropogenic activities within the factory, shown within a radius of 1 km around the factory. The mean concentrations (μg/g dry weight) in the mosses ranged from 60.9-124.5, 22.6-34.2, 13.3-14.7, 20.1-33.3 and 1,822.4-2,079.2, respectively. The mean concentrations of Pb in mosses sampled from the eastern and western side of the factory were also significantly higher than in controls. The mean concentrations of Zn, Cu, Cd, Cr, Pb and Fe in topsoil samples ranged from 7 (Pb)-2,310 (Fe) mg/kg dry wt, depending on sample means based on site direction, distance from the factory and season. There was no clear variation in metal concentrations in mosses and topsoils with direction from the factory which was consistent with the observed fluctuations in wind direction which changed from south-west in the mornings to north and south-west in the afternoons during sampling.

Phytochelatin formation kinetics and toxic effects in the freshwater alga Chlamydomonas reinhardtii upon short- and long-term exposure to lead(II)

Phytochelatins (PC) are metal-binding ligands synthesized by algae in response to elevated concentrations of various metals, such as Pb. Kinetics of PC synthesis and Pb accumulation in Chlamydomonas reinhardtii were investigated as a function of [Pb 2+] = 10 −11–10 −7 M (pPb11–pPb7.1) in the exposure medium for up to 6 h. The role of PC in Pb detoxification was explored by relating PC synthesis to the effects of Pb on growth and photosynthetic yield upon exposure to pPb9 and pPb8.3 for up to 72 h. Pb accumulation increased with increasing [Pb 2+], reaching a maximum concentration of 596 ± 77 amol/cell (intracellular concentration 2.98 mM) at pPb7.1. Low concentrations of PC 2–PC 4 were present in C. reinhardtii grown in control media without Pb addition. Upon short-term exposure, PC 2 and PC 3 synthesis was induced within minutes at [Pb 2+] ≥ pPb8 and PC 4 synthesis after a lag phase at pPb7.1. Cellular PC 2–PC 4 concentrations increased with time over 6 h and with increasing [Pb 2+]. PC concentrations after 6 h exposure to pPb7.1 were 28.5 ± 0.2 amol/cell (142 μM) PC 2, 2.8 ± 0.05 amol/cell (14 μM) PC 3 and 0.30 ± 0.01 amol/cell (1.5 μM) PC 4. Upon long-term exposure, induction of PC synthesis was detected at pPb9 and synthesis of PCs with a higher degree of polymerization was observed (PC 5). PC concentrations were lower than intracellular Pb and were thus not present at sufficiently high concentrations to immobilize accumulated Pb. Inhibition of photosynthesis and growth up to 100% was observed upon long-term exposure, whereas in short-term experiments no inhibitory effects were detected.

Toxic effects of lead and nickel nitrate on rat liver chromatin components

The biological activity of heavy metals is related to their physicochemical interaction with biological receptors. In the present study, the effect of low concentrations of nickel nitrate and lead nitrate (<0.3 mM) on rat liver soluble chromatin and histone proteins was examined. The results showed that addition of various concentrations of metals to chromatin solution preceded the chromatin into aggregation and precipitation in a dose-dependant manner; however, the extent of absorbance changes at 260 and 400 nm was different between two metals. Gel electrophoresis of histone proteins and DNA of the supernatants obtained from the metal-treated chromatin and the controls revealed higher affinity of lead nitrate to chromatin compared to nickel nitrate. Also, the binding affinity of lead nitrate to histone proteins free in solution was higher than nickel. On the basis of the results, it is concluded that lead reacts with chromatin components even at very low concentrations and induce chromatin aggregation through histone-DNA cross-links. Whereas, nickel nitrate is less effective on chromatin at low concentrations, suggesting higher toxicity of lead nitrate on chromatin compared to nickel.

Seasonal Variation of Metal Concentrations in Catfish, Blue Crab and Crayfish from Warri Coastal Water of Delta State, Nigeria

2 Abstract: The concentrations of Pb, Ni, Fe and Cd were determined using Atomic Absorption Spectrophotometer-Varian Spectral AA220 in catfish, blue crab and crayfish from Warri coastal water of Delta state. Of all the heavy metals examined, the line charts presented in Fig. 2, 3 and 4 indicate that Cd and Pb have the highest concentration while Fe and Ni have the least concentration in the three fauna considered for the experiment at both dry and wet seasons of 2008. The mean concentration values for catfish are: 0.002-2.52 mg/kg, 0.22-3.50 mg/kg, 0.002-1.48 mg/kg and 0.009-18.13 mg/kg; blue crab: 0.82-3.40 mg/kg, 0.35-2.50 mg/kg, 0.06-1.61 mg/kg and 1.62-12.88 mg/kg and crayfish: 0.22-8.00 mg/kg, 0.01-2.25 mg/kg, 0.004-0.55 mg/kg and 0.038-18.13 mg/kg for heavy metals of Pb, Ni, Fe and Cd respectively. The concentrations of the metals determined varied from one location to another and from one specie to another. Hence, Egbokodo location has the highest Cd content in catfish while Jeddo and Ughoton locations have highest Cd content in crayfish and blue crab respectively. Lastly, the order of increasing in concentration of the metals is Fe<Ni<Pb<Cd.

HEAVY METAL AND SELENIUM CONCENTRATIONS IN LIVER TISSUE FROM WILD AMERICAN ALLIGATOR (ALLIGATOR MISSISSIPPIENSIS) LIVERS NEAR CHARLESTON, SOUTH CAROLINA

Liver samples from 33 wild American alligators (Alligator mississippiensis) livers from the Charleston, South Carolina, area were analyzed for arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), mercury (Hg), nickel (Ni), lead (Pb), and selenium (Se) concentrations. Alligators are top predators and are considered a good biomonitoring species for various toxins, including heavy metals. Alligators from other areas in the US have shown high concentrations of mercury and other heavy metals, but the Charleston area, which is highly industrialized, has not been investigated. We found wide variation in hepatic heavy metal and selenium concentrations among alligators. Length and sex did not show a strong relationship with any metal based on statistical analysis. However, cluster analysis revealed three groupings of alligators based on liver metal concentrations. Alligators with low Se:Hg ratios also had high concentrations of Hg. Due to the wide variation in metal concentrations among individual alligators, we postulate that individual diet and microhabitat usage could be the cause for this variation.

Spatial distribution of heavy metals in the coastal zone of “Sfax‐Kerkennah” plateau, Tunisia

AbstractThe concentrations of selected heavy metals (Cr, Cd, Ni, Zn, Cu, Pb, Mn, and Fe) in surface sediments from the coastal zone of “Sfax‐Kerkennah” plateau (Tunisia) were studied to understand the current degree of metal contamination. The geochemical analyses showed wide spatial variations in metal concentrations. Enrichment factors (EFs) and principal component analysis revealed two distinct groups of metals. The first group corresponded to Mn and Fe that were derived from natural sources, and the second group contained Cr, Cd, Ni, Zn, Cu and to a lesser degree Pb that originated from anthropogenic sources. The localized higher EF values that were in harmony with those of the spatial distribution of element concentrations confirmed the significant impact of anthropogenic activities. On the basis of geoaccumulation index values (Igeo), these activities were shown to be responsible for important sediment contamination, especially close to the coastline. © 2010 American Institute of Chemical Engineers Environ Prog, 2011

Effects of buckwheat growth on variation of aluminum and major metals in root‐zone soil solutions

AbstractThe variation in and relationships between aluminum and other major metals including Ca, Mg, Mn, and K in root‐zone soil solutions were studied by growing buckwheat (Fagopyrum esculentum Moench. cv. Jiangxi), an Al accumulator, in pots filled with an acid soil amended with CaCO3 and unamended controls with a preinstalled nondestructive soil‐solution sampler. Soil solutions were collected every 7 d with a syringe connected to the sampler. The results showed that pH of the soil solution was not the only factor controlling the concentration of Al. Significant positive linear correlations were found between Al and Ca as well as between Al and Mg in soil solutions from the controls. The ratio of base cations (BC, Ca+Mg) to Al might partly explain the high Al resistance of buckwheat. Oxalate secretion from roots significantly activated Al in acid soils, which may be important for changes of Al in soil solutions, but it also caused decreased concentrations of Ca, Mg, and Mn. It is concluded that the variation of metal concentrations including Al, Ca, Mg, and Mn is a holistic effect involving competition for exchange sites among Ca, Mg, H, and Al, the chelation by oxalate secreted from roots, and metal uptake by buckwheat.

Quantifying restoration success and recovery in a metal‐polluted stream: a 17‐year assessment of physicochemical and biological responses

Summary 1. Evaluating the effectiveness of stream restoration is often challenging because of the lack of pre‐treatment data, narrow focus on physicochemical measures and insufficient post‐restoration monitoring. Even when these fundamental elements are present, quantifying restoration success is difficult because of the challenges associated with distinguishing treatment effects from seasonal variation, episodic events and long‐term climatic changes. 2. We report results of one of the most comprehensive and continuous records of physical, chemical and biological data available to assess restoration success for a stream ecosystem in North America. Over a 17 year period we measured seasonal and annual changes in metal concentrations, physicochemical characteristics, macroinvertebrate communities, and brown trout Salmo trutta populations in the Arkansas River, a metal‐contaminated stream in Colorado, USA. 3. Although we observed significant improvements in water quality after treatment, the effectiveness of restoration varied temporally, spatially and among biological response variables. The fastest recovery was observed at stations where restoration eliminated point sources of metal contamination. Recovery of macroinvertebrates was significantly delayed at some stations because of residual sediment contamination and because extreme seasonal and episodic variation in metal concentrations prevented recolonization by sensitive species. 4. Synthesis and applications. Because recovery trajectories after the removal of a stressor are often complex or nonlinear, long‐term studies are necessary to assess restoration success within the context of episodic events and changes in regional climate. The observed variation in recovery among chemical and biological endpoints highlights the importance of developing objective criteria to assess restoration success. Although the rapid response of macroinvertebrates to reduced metal concentrations is encouraging, we have previously demonstrated that benthic communities from the Arkansas River remained susceptible to other novel anthropogenic stressors. We suggest that the resistance or resilience of benthic macroinvertebrate communities to novel stressors may be effective indicators of restoration success that can account for the non‐additive (e.g. synergistic) nature of compound perturbations.

Bioaccumulation of Zn and Pb in &lt;i&gt;Avicennia marina&lt;/i&gt; (Forsk.) Vierh. and &lt;i&gt;Sonneratia apetala&lt;/i&gt; Buch. Ham. from Urban Areas of Mumbai (Bombay), India

Accumulation of heavy metals (Zn, Pb) was studied in two mangrove species Avicennia marina (Forsk.)Vierh. and Sonneratia apetala Buch.Ham. under field conditions. Variation in concentration of metals was found in leaf, root and sediment samples of these two species from different localities. Both the species of mangroves from different locations had high concentration of zinc when compared to lead. Lead showed less mobility towards the leaf tissue. In comparison to Sonneratia apetala, roots of Avicennia marina showed higher accumulation of the metals.

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

Stress and toxicity of four biologically important transition metals (Co, Ni, Cu and Zn) on phytoplankton in Godavari River (a tropical freshwater system) were studied to understand the fate of phytoplankton of freshwater if it receives metal contaminated water imposed by these four metals. Shift in community structure of phytoplankton and their different tolerance levels for different metals were also investigated. It was found that the variation of metal concentrations at lower level (1 × 10 −9 to 1 × 10 −8 M) did not show a dramatic change in the total biomass or concentrations of the pigment markers. At concentration of 1 × 10 −7 M of metal, Cu acted as a nutrient and helped to increase the biomass followed by Co, Ni and Zn. The variation in biomass in the freshwater system under exposure to different metals at high concentration of 1 × 10 −6 M indicates that Cu had strongest interactions with biotic ligand and was taken up by phytoplankton and acted as the most toxic metal followed by Zn, Co and Ni. Phytoplankton communities in Godavari River have different tolerance levels for different metals. Cu and Zn were found to be lethal at high concentration for both green algae and cyanobacteria. Cyanobacteria were found to be very sensitive to slight variation in Ni concentration and Co was found to be less toxic than Cu and Zn even at high exposed concentration.

Accumulation of toxic metals (Pb and Cd) in the sea urchin Diadema aff. antillarum Philippi, 1845, in an oceanic island (Tenerife, Canary Islands)

This document shows the results obtained from a study on the concentration of toxic heavy metals in the internal tissue and exoskeleton of sea urchins, collected from their natural habitat. The levels of lead and cadmium were measured by Graphite Furnace Atomic Absorption Spectrometry. The mean concentrations of lead and cadmium in the internal tissue were 304.04 and 260.54 microg/kg respectively, whereas in the shell they were 185.02 and 142.48 microg/kg. We also performed a statistical analysis of the differences in the distribution of metals between their exoskeleton and their internal content, a correlation study of the metal content in internal tissue and shell and sampling areas, and a correlation study between the metal content and sample size. Since the sea urchin Diadema antillarum presents a wide range of variation in metal content, this study suggests that this species is an excellent bioindicator of heavy metal contamination.

Metallothioneins and trace elements in digestive gland, gills, kidney and gonads of Octopus vulgaris

Metallothionein-like proteins (MT) and V, Cr, Co, Ni, Zn, Cu, As and Cd were determined in digestive gland, gills, kidney and gonads of Octopus vulgaris, from the Portuguese coast. To our knowledge these are the first data on MT in octopus. High concentrations (µgg−1, dry mass) of Zn (48050) and Cd (555) were found in digestive gland, and MT reached levels one order of magnitude above the ones registered in wild bivalves. Significantly higher levels of MT in digestive gland and gills of specimens from A and B were in line with elevated Cd concentrations. Principal component analyses (PCA) point to MT-Cd and MT-Cr associations in digestive gland and gills. Despite the high levels of Zn in specimens from B, association with Zn was not obtained. Due to the affinity of MT to various elements, it should not be excluded the possibility of Cd replacing Zn in Zn-MT. Kidney presented higher levels of Cd, Co, Ni and As than gills and gonads, and in the case of As surpassing the levels in digestive gland, but PCA showed no relation with MT. Likewise the MT levels in gonads had no correspondence to the metal concentration variation.

Transfer of cadmium and lead from soil to mangoes in an uncontaminated area, Hainan Island, China

Exposure to toxic metals from fruits is an important pathway of human exposure to soil pollutants, but few researches on metals accumulation in the soil–fruit system were performed. In this study, we conducted a systemic survey of Cd and Pb accumulations in the soil–mango ( Mangifera indica L.) system from an uncontaminated area, Hainan Island, China. Results indicated that concentrations of Cd and Pb in the soil were controlled by the parent materials, with concentrations ranging from 0.019–0.21 μg g − 1 for Cd and 8–63 μg g − 1 for Pb in total and from 0.003–0.059 μg g − 1 for Cd and 0.8–7.0 μg g − 1 for Pb in labile fractions, respectively. The concentrations of Cd and Pb in the mango fruits showed ranges of 0.3–4.2 and 0.8–209 ng g − 1 (FW), respectively, which varied significantly between cultivars. The transfer factors (TFs) of metals from soil to fruit showed significant differences between cultivars, from 0.01 to 0.025 for Cd and from 0.001 to 0.0019 for Pb. The ANOVA and correlation analyses indicated that the variations of metal in the fruit depended on the difference of cultivars, while the variations of metal concentrations within cultivar were controlled, to some extent, by the soil metal levels. Our finding suggests that the use of the individual cultivar to assess the soil metal bioavailability or metal transfer ability from soil to plant may be more precise than the use of different cultivars. Quantitative chemical analysis was performed using flame or graphite furnace atomic absorption spectroscopy.

Profile of heavy metals in some medicinal plants from Ghana commonly used as components of herbal formulations

The levels of some heavy metals in 27 medicinal plant species from Ghana were studied in order to evaluate their health implications. These plant species, especially those used in the treatment of diseases such as hypertension, diabetes and asthma may require long term usage. The metals were copper, zinc, iron, manganese, nickel and cadmium. Atomic Absorption Spectrophotometry (wet digestion) was used for the analyses, and content of metals per sample was expressed as percent µg/g. Daily total intake of these metals is discussed based on the recommended daily intake of the medicinal plants or their corresponding formulations. From the results of the study zinc, copper and cadmium were present in all the plant species examined. Manganese was present in all species except V. amygdalina. Iron was found in all except five species (82%), whilst nickel was (rather rare) detected in only eight (30%) of the plant species. Significant variations in metal content existed (P<0.05) among the medicinal plant species with respect to the heavy metals evaluated. The concentrations of copper, zinc, cadmium and manganese were within their respective maximum permissible daily levels. However, some species, especially Ocimum canum (8), Clausena anisata and Rauwolfia vomitoria had levels of iron higher than the maximum permissible level of 1000 µg/day and may require care to avoid iron toxicity. The results also highlighted the differences in contents of minerals in Lippia multiflora obtained from different locations in Ghana. The findings generally suggest that the use of these plant species for the management of diseases will not cause heavy metal toxicity and may be beneficial to the users in cases of micronutrient deficiency, as these metals were found to be present in readily bioavailable form.

Seasonal variations of metal concentrations in periphyton and taxonomic composition of the algal community at a Yenisei River littoral site

AbstractThe concentrations of metals K, Na, Ca, Mg, Fe, Mn, Zn, Cu, Ni, Pb, Co and Cr, in the water and periphyton (epilithic algal communities) were studied at a site in the middle stream of the Yenisei River (Siberia, Russia) during three years using monthly sampling frequencies. Despite considerable seasonal variations in aquatic concentrations of some metals, there was no correlation between metal contents in the water and in periphyton. Seasonal concentration variations of some metals in periphyton were related to the species (taxonomic) composition of periphytic microalgae and cyanobacteria. Enhanced levels of Ni and Co in periphyton in late autumn, winter, and early spring were likely caused by the predominance of cyanobacteria in the periphytic community, and annual maximum levels of K in periphyton in late spring and early summer were attributed to the domination of Chlorophyta, primarily Ulothrix zonata.

Cadmium speciation and accumulation in periphyton in a small stream with dynamic concentration variations

Accumulation of cadmium in periphyton was investigated under field conditions while Cd concentration and speciation were dynamically varying in a small stream during rain events. Speciation in water was determined in situ by diffusion gradient in thin-films (DGT) and by modeling of complexation with fulvic acids. During the rain events, dissolved Cd concentrations increased from 0.17 nM to 0.27–0.36 nM, and 70–97% were DGT-labile. Cd content in periphyton closely followed Cd concentrations in water, despite higher concentrations of Zn and Mn, and may be controlled by either free or DGT-labile Cd concentrations. Decrease of Cd content in periphyton after the rain events was slower than the decrease of Cd concentration in water. Concentrations of Zn, Mn, Cu, Pb and Fe in periphyton also followed the dynamic variations of metal concentrations in water. Repeated exposure of periphyton to elevated dissolved Cd may lead to Cd accumulation.

Consumption of the Clam, Galatea paradoxa (Born 1778) in Ghana: Human Health Implications with Reference to Heavy Metals

This study was carried out over a 7-month period at two active clam fishing locations, Ada and Aveglo at the Volta estuary in Ghana, to assess the levels of some heavy metals: Mn, Zn, Fe and Hg in whole soft tissue of Galatea paradoxa and their suitability for human consumption. The clam, Galatea paradoxa (Born 1778) is a commercially important bivalve species exploited mainly for its flesh. In Ghana, it constitutes an important and affordable protein source and is consumed by the riparian communities and beyond the Volta estuary. For each sampling location 30 clams were obtained and grouped into three size classes of 10 individuals, each based on shell lengths. The categorization was as follows: small (25–40 mm), medium (41–55 mm), and large (above 55 mm). The groupings were chosen based on the three dominant size groups in the natural population to give a broad and representative range of metal concentrations in the clams. The concentrations of zinc, iron and manganese were determined using a flame Atomic Absorption Spectrophotometer (AAS) and mercury concentrations were determined using an Atomic Mercury Analyzer. The results were expressed as total concentrations (μg/g dry weight (dw)). There were no significant differences (p>0.05) in Mn, Fe and Zn concentrations among the different size classes except for Hg concentration in clams from Ada, indicating a similar bioavailability of Mn, Fe, Zn at both locations and, possibly, an efficient metabolism to keep the concentrations of Mn, Fe and Zn relatively similar in the tissues of the different clam sizes. Spatial variations in metal concentrations (i.e., Ada small vs. Aveglo small, Ada medium vs. Aveglo medium, and Ada large vs. Aveglo large) were not significant for Mn, Zn and Hg for all the size classes. However, variations in Fe concentration in the large-sized clams was significant (p<0.05).

Metal enrichment and magnetic properties of core sediments from the eastern Yellow Sea, East Asia: Implications for paleo-depositional change during the late Pleistocene/Holocene transition

To investigate the paleo-depositional environments, sediment cores YJ1 and YJ2 from a tidal flat of the eastern Yellow Sea were analyzed for the vertical variations of metal concentrations, particle size, clay mineralogy, magnetic properties, and total organic carbon content (TOC). Fe (and Mn) concentrations determined by both partial and total acid extraction increased at 15 m depth in YJ1 and 10 m in YJ2. The layer directly below these Fe-rich brownish horizons showed dramatic decreases in clay mineral content and trace metals (Zn, Pb, Cu, Cr, Co, Ni, and As), but increases in sand fraction, magnetic susceptibility, and TOC. All results were inverse in the upper metal-rich layer. These dramatic changes in multi-parameters are likely due to an environmental change during the late Pleistocene/Holocene transition. The rapid environmental change (sand-rich and oxic → clay-rich and anoxic) resulted in aqueous dissolution of redox-sensitive metals (e.g., Fe and Mn) from the lower sandy layer materials. The dissolved metals diffused upward and concomitantly were immobilized within the upper clay-rich layer. The reprecipitated Fe (or Mn) (hydro)oxides then scavenged trace metals by coprecipitation and/or adsorption. This study suggests that metal distribution patterns can provide new insights into the paleo-depositional processes during the Pleistocene–Holocene period.

Variation in Metal Contents of Plants in Vegetable Garden Sites in Kano Metropolis

The concentrations (mg/Kg) of Cr, Co, Cu, Fe, Mn, Ni, Pb and Zn were determined in seven different vegetables which were obtained from sharada, kwakwachi and Jakara irrigation gardens in the Kano metropolis using Atomic Absorption Spectrophotometry (AAS). Samples were collected during both dry and rainy seasons. The mean levels of metals obtained ranged widely from 0.34 mg/Kg Cr to 27.35 mg/Kg Fe. The relative abundance of metals in vegetables analyzed followed the sequence Fe > Zn > Mn > Cu > Ni > Pb > Co > Cr. Reductions of metal levels ranging from 8.25% Fe in onion to 45.19% Ni in Okra were recorded in rainy season samples over those of the dry season. @JASEM

RETRACTED: Layer silicates modified with 1,4-bis(3-aminopropyl)piperazine for the removal of Th(IV), U(VI) and Eu(III) from aqueous media

Natural montmorillonite (M) and synthetic kanemite (K) have been functionalized with 1,4-bis(3-aminopropyl)piperazine reacted with methylacrylate to yield new inorganic-organic chelating materials. The original and modified materials were characterized by X-ray diffractometry, textural analysis, SEM and nuclear magnetic nuclei of carbon-13 and silicon-29. The chemically modified clay samples (M-APPMA and K-APPMA) showed modification of its physical-chemical properties including: specific area 45.0m(2)g(-1) (M) to 978.8 m(2)g(-1) (M-APPMA) and 23.5m(2)g(-1) (K) to 898.9 m(2)g(-1) (K-APPMA). The ability of these materials to remove thorium(IV), uranyl(VI) and europium(III) from aqueous solution was followed by a series of adsorption isotherms, which were fitted to non-linear Sips adsorption isotherm model. To achieve the best adsorption conditions the influence of pH and variation of metal concentration were investigated. The energetic effects (Delta(int)H degrees , Delta(int)G degrees and Delta(int)S degrees ) caused by metal ions adsorption were determined through calorimetric titrations.