High Metal Accumulation Research Articles

Effect of drain effluents on hardness of water of the ponds of Varanasi

Water is necessity of all living being, it helps in the digestion of food as well as provides necessary minerals required to the body. But, harden water has its demerits on human life both ways for drinking as well as for normal use. The soap consumption requires a high budget and accumulation of harmful metals in excess may damage the human health. In ponds there are greater chances of heavy metals like Ca, Ba, Sr, Mg, Fe etc. which are conveyed to ponds through drains. The quantitative monitoring of such heavy metals which render hardness to ponds water is essential. In the present dissertation periodic estimations of Varanasi city have been made and the utility results have been drawn their from. In the undertaken study sites the heavy metals except Ca were obtain in extremely trace amounts.

Evaluation of urban contamination with trace elements in city parks in Serbia using pine (Pinus nigra Arnold) needles, bark and urban topsoil

Urban environments are strongly influenced by anthropogenic activities, which are often reflected by a high degree of contamination in relation to the natural environment. Concentrations of five trace elements (B, Cr, Cu, Mn and Zn) were determined in the surface layers of soil (0–10 cm), bark, and 1- and 2-year-old needles of Pinus nigra Arnold in urban parks in four cities in Serbia exposed to different pollution sources. The sampling locations in parks were chosen based on their proximity to industrial complexes and heavy traffic. Soil indices such as the contamination factor and the degree of contamination were used to assess the potential ecological risk in urban topsoil. Although some metal concentrations (Cr, Cu, Mn and Zn) occasionally exceeded the background values, they posed no threat to the environment. The content of the selected metals in needles varied depending on the metal, the age of the needles, and the site. It is evident from this study that pine needles do not accumulate trace elements in large (mg kg−1) quantities. The highest metal accumulation was observed in the soil and needles at sites with heavy industry and heavy traffic, such as Smederevo and Belgrade, which were the two most polluted sites.

High contamination in the areas surrounding abandoned mines and mining activities: An impact assessment of the Dilala, Luilu and Mpingiri Rivers, Democratic Republic of the Congo

Abandoned mines and mining activities constitute important sources of toxic metals and Rare Earth Elements (REEs) affecting surrounding environmental compartments and biota. This study investigates the contamination degree and distribution of toxic metals and REEs in contrasting sediment, soil and plant samples surrounding rivers in the African copperbelt area characterized by the presence of numerous abandoned mines, artisanal and industrial mining activities. ICP-MS results highlighted the highest concentration of Cu, Co and Pb in sediments reaching values of 146,801, 18,434 and 899 mg kg−1, respectively. In soil, the values of 175,859, 21,134 and 1164 mg kg−1 were found for Cu, Co and Pb, respectively. These values are much higher than the sediment guidelines for the protection of aquatic life and international soil clean-up standards. Enrichment factor and geoaccumulation index results indicated important contribution of mining activities to the study sites pollution in addition to natural background. Highest metal accumulation in leaves of Phalaris arundinacea L., was observed, reaching values of 34,061, 5050 and 230 mg kg−1 for Cu, Co, and Pb, respectively. The ∑REE concentration reached values of 2306, 733, 2796 mg kg−1 in sediment, soil and plant samples, respectively. The above results were combined with geographical information including satellite imagery, hydrography and mining concessions. Maps were produced to present the results in a comprehensive and compelling visual format. The results will be disseminated through an innovative mapping online platform to simplify access to data and to facilitate dialogue between stakeholders.

Metal compartmentalization in different biomass portions of Helianthus annuus L. and Sorghum bicolor L. grown in an agricultural field inside an urban fabric

Plant-based products comprise the vast majority of human and animal nutrition, and metal concentration and accumulation inside food can affect human health. Recently, agricultural soils are often located in close proximity of urban fabrics and factories, so that risk of contamination is high. A field study, carried out in summer 2014, aimed to: i) evaluate the chemical, biological and ecotoxicological characteristics of an agricultural soil in the neighbourhood of the city of Naples (Southern Italy); ii) detect Cd, Cr, Cu, Ni and Pb concentrations and accumulations in roots of sunflower and sorghum; iii) distinguish the potential main pathway (by roots or leaves) of metal uptake in the two crop species. Metal concentrations were measured in soil, roots, stems, leaves and seeds. Besides, the metal bioaccumulation and translocation factors were also calculated. Soils resulted slightly contaminated by Cu and Pb, deriving by both agricultural practices and urban inputs, but did not differ in biological and ecotoxicological characteristics. Cu was the most abundant metal and roots appeared the main path of metal uptake for both the crop species. In sunflower, roots apparently limit the absorption of Pb as well Cu and Cd uptake by leaves from the atmosphere cannot be excluded. Sunflower, likely for the higher biomass and faster growth rate as compared to sorghum, showed an overall higher metal accumulation, particularly high for Cd and Cu in the seeds. CapsuleSorghum and sunflower, grown in an agricultural field inside an urban fabric, showed a different metal compartmentalization and accumulation in biomass portions used in human dietary

Heavy Metal Contamination of Ground Water from an Unlined Landfill in Bulawayo, Zimbabwe.

Background.Developing countries such as Zimbabwe deal with challenges in solid waste management such as insufficient waste recycling, hazardous wastes that are not separated for safe disposal, and landfills that are not properly engineered to prevent groundwater pollution. For these reasons, landfills in developing countries pose serious environmental and public health hazards.Objectives.The objective of this study was to assess heavy metal release and groundwater pollution from an unlined landfill in Bulawayo, Zimbabwe. The purpose of the study was to explore environmental and public health risks posed by improperly managed landfills in developing countries.Methods.We assessed levels of metal release from Richmond landfill in the city of Bulawayo, Zimbabwe by measuring lead, cadmium, chromium and copper levels in landfill soil, leachate and plants. We also monitored metal levels in groundwater from boreholes located in a residential area in the vicinity and downgradient of the landfill within a range of 800–2135 m. Soil was characterized at the landfill to assess potential sources of heavy metals.Results.All metals that were assessed were present in landfill soil and in leachate. There was high metal accumulation in weeds that were growing at the landfill, indicating mobility and bioavailability of the metals. Groundwater from nearby boreholes had high levels of lead (Pb) and cadmium (Cd) which were negatively correlated to distance from the landfill (p<0.01), indicating contamination from the landfill. The Pb and Cd levels exceeded World Health Organization standards for drinking water quality, posing health hazards to the communities who rely on the water. Solid waste at the landfill consisted of soft plastics (33%), hard plastics (18.6%), metals (3%), paper (8%), electronic waste (0.8%), organics (15.3%) and various other types (21.3%).Discussion.A combination of factors may be attributed to groundwater contamination. These include the co-disposal of metallic and electronic wastes at the landfill, lack of membrane lining at the landfill, inadequate leachate management and the porous geo-physical characteristics of the sub-surface at the landfill site.Conclusions.Our study highlights adverse environmental and public health consequences of co-disposal of metals and electronic wastes at improperly engineered municipal landfills. This is a ‘wake-up’ call for policy makers in developing countries to improve solid waste management.

Association of exposure to manganese and iron with striatal and thalamic GABA and other neurometabolites — Neuroimaging results from the WELDOX II study

ObjectiveMagnetic resonance spectroscopy (MRS) is a non-invasive method to quantify neurometabolite concentrations in the brain. Within the framework of the WELDOX II study, we investigated the association of exposure to manganese (Mn) and iron (Fe) with γ-aminobutyric acid (GABA) and other neurometabolites in the striatum and thalamus of 154 men. Material and methodsGABA-edited and short echo-time MRS at 3T was used to assess brain levels of GABA, glutamate, total creatine (tCr) and other neurometabolites. Volumes of interest (VOIs) were placed into the striatum and thalamus of both hemispheres of 47 active welders, 20 former welders, 36 men with Parkinson’s disease (PD), 12 men with hemochromatosis (HC), and 39 male controls. Linear mixed models were used to estimate the influence of Mn and Fe exposure on neurometabolites while simultaneously adjusting for cerebrospinal fluid (CSF) content, age and other factors. Exposure to Mn and Fe was assessed by study group, blood concentrations, relaxation rates R1 and R2* in the globus pallidus (GP), and airborne exposure (active welders only). ResultsThe median shift exposure to respirable Mn and Fe in active welders was 23μg/m3 and 110μg/m3, respectively. Airborne exposure was not associated with any other neurometabolite concentration. Mn in blood and serum ferritin were highest in active and former welders. GABA concentrations were not associated with any measure of exposure to Mn or Fe. In comparison to controls, tCr in these VOIs was lower in welders and patients with PD or HC. Serum concentrations of ferritin and Fe were associated with N-acetylaspartate, but in opposed directions. Higher R1 values in the GP correlated with lower neurometabolite concentrations, in particular tCr (exp(β)=0.87, p<0.01) and choline (exp(β)=0.84, p=0.04). R2* was positively associated with glutamate-glutamine and negatively with myo-inositol. ConclusionsOur results do not provide evidence that striatal and thalamic GABA differ between Mn-exposed workers, PD or HC patients, and controls. This may be due to the low exposure levels of the Mn-exposed workers and the challenges to detect small changes in GABA. Whereas Mn in blood was not associated with any neurometabolite content in these VOIs, a higher metal accumulation in the GP assessed with R1 correlated with generally lower neurometabolite concentrations.

Assessment of the bioaccumulation of selected metals in Channa punctatus and Rita rita and exposure evaluation in humans

The present study deals with the physico-chemical characterization of river water and evaluation of metal accumulation in vital tissues of fish Channa punctatusand Rita rita. Accumulation of hazardous metals (e.g. Cr, Cd and Pb) in tissues was higher than the Food and Agriculture Organization (FAO) regulations. Application of the metal pollution index (MPI) revealed that highest metal accumulation was in gills followed by liver, and least in muscle tissues in C. punctatus; whereas metal accumulation was highest in muscle tissue in R. rita. Ingestion dose for Cr, Fe, Co, Cd and Pb in samples from both species was found higher than permissible level prescribed by US Environment Protection Agency (USEPA). However, ingestive dose for Mn, Ni and Zn were found under the permissible guidelines.

Abiotic Stress Responses in Plants: Potential Targets on Studying Heavy Metal Stress tolerance in Bryophytes

Pollution of the biosphere with heavy metals has phenomenally increased since the commencement of industrial revolution. It poses several environment and health concerns. High regeneration and metal accumulation capacity the possibility of genetic transformation by homologous recombination extend the candidature of bryophytes as promising experimental models for heavy metal stress tolerance studies. Plants use several abiotic stress pathways which share common elements that are potential “nodes” for cross talks. Common elements/ molecules, which are likely to occur early in several stress response cascades in bryophytes seem to be the potential targets for heavy metal tolerance studies that can be worked out in future, at biochemical, protein and gene level.

Assessment of metal contamination in the Hun River, China, and evaluation of the fish Zacco platypus and the snail Radix swinhoei as potential biomonitors.

The Hun River is a major tributary of the Liao River in the northeast area of China and provides drinking water for 23 million local residents. This study was designed to assess the severity of metal contamination in the Hun River and the potential use of indigenous organisms (the fish Zacco platypus and the snail Radix swinhoei) as biomonitors of metal contamination. Water, sediment, and the native fish and snails were collected at four sampling sites that differed in their physicochemical characteristics and their contamination levels. The samples were analyzed for Cd, Cr, Cu, Ni, Pb, and Zn by ICP-MS. The results showed that although the overall potential ecological risks of the metals were low at our sampling sites, Cd posed a noteworthy ecological risk. Strong correlations were obtained between Cd concentrations in the organisms and in the environment. The results indicated that Z. platypus and R. swinhoei can be useful biomonitoring species for assessing Cd contamination. Biomonitoring with the snail may be most effective when focused on the gonad/digestive tissue (because of the high metal accumulation there), but further work is needed to confirm this.

Lead, Cadmium and Iron Concentrations in &amp;lt;i&amp;gt;Zea Mays&amp;lt;/i&amp;gt; Grown Within the Vicinity of Ori-Ile Battery Waste Dumpsite, Olodo, Ibadan, Nigeria

Agricultural produce resulting from the cultivation of polluted soil can result in undue exposure and health hazards for its consumers at different level along the food chain. Available literature has shown that maize absorbs and accumulates toxic heavy metals from polluted soils. This study was designed to determine the concentration of lead (Pb), cadmium (Cd) and iron (Fe) within the leaf, stem, grains and root of maize grown on Ori-Ile battery waste dumpsite, Olodo, Ibadan Nigeria. Soil samples were collected every two months (March 2008 to July 2009) from the waste dumpsite and along the direction of the garden at 5m interval from the edge of the waste dump site. To determine the levels of uptake and accumulation of Pb, Cd, and Fe, maize was planted in a nearby house garden, situated within 25m distance away from the waste dumpsite and the root, stem, leaf and grains were harvested at maturity. All soil samples collected and the harvested maize parts were analysed for Pb, Cd, and Fe. Concentrations of Pb, Cd and Fe in soil were found to range from 3265.8&plusmn;517.8 to 4351.3&plusmn;1068.2; 163.96&plusmn;23.2 to 258.38&plusmn;123.1; 7712.90&plusmn;473.8 to 8130.00&plusmn;808.4 mg/kg respectively. These were significantly higher than values obtained from the reference soil (157.0&plusmn;39.8, 2.2&plusmn;1.2, 976.3&plusmn;353.9 mg/kg respectively) and National Environmental Standard Regulation Agency (NESREA) limits (164mgPb/kg and 50mgCd/kg). Also, soil contamination factor values obtained were greater than 6 and this indicated severe contamination. Concentrations of Pb, Cd and Fe in maize-parts were significantly higher (P &le; 0.05) than those cultivated on the reference site soil. Roots had the highest concentration of Pb (40.95&plusmn;1.98 mg/L) and Cd (2.84&plusmn;0.19 mg/L). In all maize-parts, bio-accumulation factor of the heavy metals was less than 1. Overall, these results have shown that the levels of metals in soil were several folds above the limits set by NESREA. Also, the range within the analysed plant parts was above the normal limit recommended for plants. High accumulation of heavy metals found in the soils of Ori-Ile battery waste dumpsite, Olodo, Ibadan bio-accumulated in maize-roots. Therefore, maize root is actively involved in phyto extraction of heavy metals from contaminated soils.

Performance of an up-flow anaerobic sludge bed (UASB) reactor for treating landfill leachate containing heavy metals and formaldehyde

Municipal Solid Waste (MSW) landfill leachate is a serious environmental issue and treated using various methods, mostly involving biological treatment. In the present study, an up-flow anaerobic sludge bed (UASB) was used for the treatment of matured landfill leachate that contains heavy metals (As, Fe, Ni, and Cd) and Formaldehyde (FA). Accordingly, the OLR to the UASB reactor was gradually increased from 0.125 to 2.5 kg CODm-3d-1, to observe the process performance. The process performance of the reactor was characterized in terms of pH, Chemical Oxygen Demand (COD) removal, Total Volatile Acid (TVA) production, Mixed Liquor Suspended Solids (MLSS), Mixed Liquor Volatile Suspended Solids (MLVSS) washout, and Methane composition. Results showed that at a Hydraulic Retention Time (HRT) of 4 days and an OLR of 0.125 kg CODm-3d-1, up to 79.04% COD removal efficiency was observed. However, when the OLR was increased gradually from 0.375 to 2.5 kg CODm-3d-1, the COD removal efficiency decreased to 9.5%, suggesting that the high accumulation of heavy metals may have inhibited the methanogens. During this period, the heavy metal and formaldehyde concentration were 9.40, 0.43, 0.50, 12.80 and 8.60 mgL-1 respectively.

Accumulation of Lead, Cadmium and Iron in Topsoil of Ori-Ile Battery Waste Dumpsite and Surrounding Gradient Point Areas at Olodo, Ibadan, Nigeria

The disposal of waste is proving to be a major public health issue and a vital factor affecting the quality of the environment especially in the developing countries. Battery waste consists of toxic heavy metals and its incongruous disposal on the Ori-Ile battery waste dumpsite at Olodo, Ibadan has elicited public health concerns. This study was designed to determine the concentration of lead (Pb), cadmium (Cd) and iron (Fe) within the topsoil of Ori-Ile battery waste dumpsite and surrounding gradient point areas at Olodo, Ibadan, Nigeria. An auto-battery Waste Dumpsite (WD), Ori-Ile, Olodo was purposively selected for the study. One hundred and thirty six (136) soil samples were collected every two months (March 2008 to July 2009) from the waste dumpsite and along the along North, South, East and West (N, S, E, W) directions at 5 m intervals from the edge of the wastedump site. Control soil samples were collected from Moor Plantation (MP), Ibadan. All soil samples collected were analyzed for Pb, Cd, and Fe. Mean concentrations of Pb, Cd and Fe concentration (mg/kg) in topsoil from the waste dumpsite was Pb: 4273.8±1436.7, Cd: 258.4±123.1, Fe: 7910.0±791.5 while that from North was Pb: 4693.8±1107.9, Cd: 274.3±94.8, Fe: 8346.7±740.0; South was Pb: 4353.3±867.0, Cd: 255.2±71.4, Fe: 8189.6± 603.5; East was Pb: 4351.3±832.9, Cd: 248.2±65.6, Fe: 8130.0±639.5; West was Pb: 4698.3±1020.8, Cd: 278.4±86.9, Fe: 7851.3±676.8 respectively. These were significantly higher than values obtained from the reference soil (157.0±39.8, 2.2±1.2, 976.3±353.9 mg/kg respectively) and National Environmental Standard Regulation Agency (NESREA) limits (164mgPb/kg and 50mgCd/kg). Also, soil contamination factor values obtained were greater than 6 and this indicated severe contamination. Overall, these results have shown that the levels of Pb, Cd and Fe in all sampled topsoil were several folds above the limits set by NESREA. High accumulation of heavy metals was found in the topsoil of Ori-Ile battery waste dumpsite, Olodo, Ibadan and its surroundings and this could lead to further contamination of surface water, ground water and living organisms within this polluted sites. The health of all living biota within the area could also be negatively impacted.

An Assessment of the Bivalve Perna viridis, as an Indicator of Heavy Metal Contamination in Paradise Point of Karachi, Pakistan

The edible bivalves Perna viridis (green mussel), (n = 100) were analysed for their total Hg,Pb, Cu, Ni, Zn, Co, Fe, Cr, Cd, and Mn concentrations to indicate heavy metal contamination in ParadisePoint of Karachi coast using atomic absorption spectrophotometer. There are large seasonal variations inthe metal concentrations of Mn (0.025-0.67 µg/g), Fe (0.055-7.740 µg/g), Ni (0.004-0.52 µg/g), Hg (0.0001-0.004 µg/g), Zn (0.04-3.32 µg/g), Cu (0.008-1.66 µg/g), Pb (0.022-2.43 µg/g), Co (0.01-0.044 µg/g), Cd(0.04-0.88 µg/g) and Cr (0.13-1.20 µg/g) recorded in bodies/soft tissues of P. viridis obtained in the samplesof the year 1993 and 2012 at the Paradise Point of Karachi coast. The results of heavy metals are in thefollowing descending order of concentration in the samples collected in the year 1993: Fe&gt;Cr&gt;Zn&gt;Mn&gt;Pb&gt;Cd&gt;Cu&gt;Ni&gt;Co&gt;Hg, while Fe&gt;Zn&gt;Pb&gt;Cu&gt;Cr&gt;Cd&gt;Mn&gt;Ni&gt;Co&gt;Hg order was recorded in samplescollected in the year 2012. The high accumulation of metals was found mostly in the samples collectedin the year 2012 when compared with the samples of the year 1993. This is an indication that the areaunder study showed signs of being exposed to significant levels of heavy metal pollution due to directdischarge of industrial and domestic wastes along the coast. The concentrations of these heavy metals werelower than the permissible limits for human consumption. However, if this pollution persists, it can proveto be very detrimental in future.

Spatial distribution of heavy metals in the surface soil of source-control stormwater infiltration devices - Inter-site comparison.

Stormwater runoff infiltration brings about some concerns regarding its potential impact on both soil and groundwater quality; besides, the fate of contaminants in source-control devices somewhat suffers from a lack of documentation. The present study was dedicated to assessing the spatial distribution of three heavy metals (copper, lead, zinc) in the surface soil of ten small-scale infiltration facilities, along with several physical parameters (soil moisture, volatile matter, variable thickness of the upper horizon). High-resolution samplings and in-situ measurements were undertaken, followed by X-ray fluorescence analyses and spatial interpolation. Highest metal accumulation was found in a relatively narrow area near the water inflow zone, from which concentrations markedly decreased with increasing distance. Maximum enrichment ratios amounted to >20 in the most contaminated sites. Heavy metal patterns give a time-integrated vision of the non-uniform infiltration fluxes, sedimentation processes and surface flow pathways within the devices. This element indicates that the lateral extent of contamination is mainly controlled by hydraulics. The evidenced spatial structure of soil concentrations restricts the area where remediation measures would be necessary in these systems, and suggests possible optimization of their hydraulic functioning towards an easier maintenance. Heterogeneous upper boundary conditions should be taken into account when studying the fate of micropollutants in infiltration facilities with either mathematical modeling or soil coring field surveys.

Endurance assessment of Eichhornia crassipes (Mart.) Solms, in heavy metal contaminated site–A case study

AbstractIn this study, the ability to hyper accumulate heavy metals from contaminated site by water hyacinth (Eichhornia crassipes) was monitored. The heavy metal-contaminated habitat was validated by X-ray diffraction and energy dispersive X-ray elemental spectrometry analysis of the soil samples. Heavy metal contamination in soil and water; accumulation in foliar, root and bulb tissue samples were determined by atomic absorption spectroscopy and were monitored as a function of accumulation in different tissues. Significant differences were recorded in the bioaccumulation capability of heavy metals by different tissue. Discrete variation in protein profile of leaves and high expression of alcohol dehydrogenase (ADH), peroxidase (POX) and altered regulation of esterase (EST) in root tissue was observed in contaminated site grown Eichhornia. The high metal accumulation efficiency of water hyacinth due to the biomass production suggests this species as reliable organic biomarker for heavy metal contamination.

Bioaccumulation of Heavy Metals in Anuran Tadpoles: A Study in Barak Valley, Assam

Heavy metal pollution plays an important role in global biodiversity decline. However, there is paucity of information concerning the effects of metals on amphibians. In the present study, investigations were made on the accumulation of heavy metals, copper (Cu) and lead (Pb) in water, sediment and tadpoles inhabiting the water bodies of Barak Valley, Assam. Tadpoles of six different anuran species, Hoplobatrachus tigerinus , Leptobrachium smithi , Clinotarsus alticola , Fejarvarya sp., Sylvirana leptoglossa and Euphlyctis cyanophlyctis were selected for this purpose. Heavy metal concentrations were determined in intestine, liver and tail of tadpole samples of these species. The results revealed that the copper concentration in water samples was within the maximum permissible limit of WHO (2 mg L -1 ), but the concentration of lead in water samples increased beyond the permissible limit of WHO (0.01 mg L -1 ) resulting in possibilities of higher accumulation of the metal in tadpoles and decline of amphibians’ population. Total concentration of Cu in the tadpoles of different species of amphibians followed the order: H. tigerinus > S. leptoglossa > E. cyanophlyctis > C. alticola > Fejarvarya sp. > L. smithi , while concentration of lead followed the order: E. cyanophlyctis > C. alticola > S. leptoglossa > Fejarvarya sp.> H. tigerinus > L. smithi .

Metals from mine waste as potential cause of oxidative stress in burrowing crab Neohelice granulata from San Antonio bay

The Natural Protected Area San Antonio bay is of particular importance for its congregation of migratory shorebirds and it has been declared one of the Western Hemisphere Shorebird Reserve Network International site (WHSRN). Present study represents the first assessment of variation on oxidative stress biomarkers in male crab Neohelice granulata from San Antonio bay (Río Negro, Argentina) under field conditions, associated mainly to metal contamination coming from passive mining wastes. Three sites were sampled once every three months from November 2012 to August 2013 within this sea inlet (Pile, Fishery and Port) and a control site at the southeast of the bay (Punta Perdices). Accumulation of Ni, Zn, Cr and Al varied only with seasons although without a constant trend, meanwhile Cd, Cu and Pb also varied among sites being highest in Pile and Port. Biochemical results indicated that variations in catalase activity was only site specific being maximum in Pile; meanwhile lipid radical, α-tocopherol and metallothioneins were only seasonal specific being higher in autumn and winter. Seasonal variation was also found for total thioles, being the content higher in summer and autumn than in winter. Correlation analysis revealed that malondialdehyde and α-tocopherol have a positive association with Al and negative with Ni, meanwhile GST has a positive association with Fe. Crabs from the closest area to the waste pile did not exhibit a differentiated oxidative pressure despite the higher accumulation of metals. It is possible that crabs from contaminated areas have developed a tolerance to metals, indicating a strong ecotoxicological selective pressure. More studies are needed to assess whether there is a transfer of metals through the food chain.

Seasonal profile of metal accumulation in the acanthocephalan Pomphorhynchus laevis: a valuable tool to study infection dynamics and implications for metal monitoring

BackgroundA large number of studies demonstrated that acanthocephalans exhibit a high metal accumulation potential and thus can be used as sensitive accumulation indicators. However, similar to free-living bioindicators, a seasonal variation in metal concentrations in parasites might occur. Accordingly, the influence of seasonality has to be elucidated if parasites should be applied as sentinels.MethodsIn order to assess a possible seasonal profile of element concentrations, the concentrations of As, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, V and Zn in the acanthocephalan Pomphorhynchus laevis and in its host barbel (Barbus barbus) were analysed in a seasonal manner (spring, summer and autumn) using inductively coupled plasma mass spectrometry (ICP-MS).ResultsFive elements (As, Cd, Cu, Pb and Zn) were detected in significantly higher concentrations in the parasites compared to host muscle, intestine and liver. Their levels in P. laevis showed a clear seasonal pattern, while the concentrations in the fish tissues remained similar during the year. The highest concentrations in the parasites were found in autumn, followed by spring and summer. Evidence from the literature suggests that this profile coincides with the seasonality of acanthocephalan transmission, as their annual concentration profile reflected the mean individual weight pattern during the year. Parasite infrapopulations in autumn consisted mainly of young worms which are characterised by an accelerated metabolism and a higher surface to volume ratio resulting in higher element concentrations when compared to older worms which are assumed to slow down their metabolism and additionally excrete metals with their eggs.ConclusionsBased on the available data from the present study and literature, a model is suggested, which visualises the accumulation kinetic of several elements under natural conditions. According to the element accumulation data the lifespan of P. laevis in barbel was roughly estimated to range between six and eight months.

A Study on Bioaccumulation of Heavy Metals in two Anuran Tadpoles: Clinotarsus alticola and Leptobrachium smithi from Rosekandy Tea Estate, Cachar, Assam

Considering the significance of heavy metal pollution in aquatic system bioaccumulation of heavy metals in two species of tadpoles namely Clinotarsus alticola and Leptobrachium smithicollected from tea gardens of Barak valley, Assam was studied. Aquatic life is affected by heavy metal pollutants present in water as well as in sediment. The result of the study revealed that the concentration of iron, chromium, cadmium and lead in water samples was higher than the permissible limit of 0.3, 0.05, 0.003, 0.01 mg/L respectively but that of copper and zinc concentration was within the maximum permissible limit of 2 mg/L and 3 mg/L (WHO, 2005). The accumulation pattern of different heavy metals in different organs viz., intestine, liver and tail was studied.Overall the metal burden in different organs of Clinotarsus alticola and Leptobrachium smithi was in the order of liver&gt;tail&gt;intestine. Liver had highest accumulation of metals while intestine accumulated the least.Iron (Fe) was highly and zinc (Zn) was the least accumulated metal in both the tadpoles. The accumulation of heavy metals might be due to tea plantation influx water, domestic and associated anthropogenic activities.

Elucidation of zinc and copper induced oxidative stress, DNA damage and activation of defence system during seed germination in Cassia angustifolia Vahl

Investigations conducted on Cassia angustifolia to see the effect of zinc (Zn) and copper (Cu) during seed germination, revealed drastic toxicity on seedling growth, alteration in antioxidant enzymes, morphological changes and metal accumulation in various plant parts. Seeds were germinated on Knop’s medium containing Zn and Cu individually in various concentrations (0, 1, 10, 50, 100 and 200mgL−1). Decline in seed germination initiated above 1mgL−1 and maximum inhibition was seen at 200mgL−1 where it was 40 and 25.0%, respectively under Zn and Cu over control (67.67%). Average shoot length decreased from 5.53cm (control) to 2.1 and 1.4cm whereas average root length decreased from 7.12cm (control) to 1.5 and 0.3cm under Zn and Cu, respectively. Atomic absorption spectroscopy revealed that maximum Zn and Cu (1682.48 and 9516.99mgkg−1 dry weight, respectively) were stored in roots. Superoxide dismutase activity increased up to 2.71 and 3.27 fold at 200mgL−1 Zn and Cu, respectively. Catalase, ascorbate peroxidase, guaiacol peroxidase and glutathione reductase followed similar trend. Malondialdehyde and proline content accounted for 52.7μmolmg−1 and 10.0μmolg−1 fresh weight, respectively in control seedlings. Malondialdehyde increased up to 2.5 and 3.33 fold and proline up to 9.42 and 11.20 fold at 200mgL−1 Zn and Cu, respectively. Comet assay revealed extensive DNA damage at higher concentration and protein analysis showed various low molecular weight proteins (20–14kDa) at higher concentration. This is our first report of in vitro heavy metal stress study on C. angustifolia. Induction of anti-oxidative response and proline accumulation suggests the tolerance strategy adopted by C. angustifolia and its high metal accumulation potential can be utilized in phytoremediation.