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Arsenic (As) is a metalloid that causes severe water pollution due to its extravagant toxicity. Ceriodaphnia dubia, a freshwater crustacean, was selected as a model system to evaluate the degree of time and dosage dependent acute toxicity caused by pentavalent As [As(V)]. C. dubia were collected from a natural pond and treated with different concentrations of As(V) for 24 hours and 48 hours. For both 24 hours and 48 hours treatment periods, the mortality rates were increased significantly ( P< 0.05) with increase in As(V) concentrations. Simultaneously, it was also observed that As(V) - induced mortality in C. dubia also depended on the time of exposure to the metalloid. We propose this model as a low-cost technique towards rapid screening of water quality in relation to As contamination.
Water bodies are the final sinks of all pollution with more than 90% of contaminants found in suspended particulates and bottom sediments. Only less than 10% is retained in the water column yet it attracts and receives great research attention. The pollution status and the potential ecological risk of three pools of water along a stream due to heavy metal enrichment from a nearby active gold mining tailings dam were assessed. The upstreamdownstream and sedimentological approaches to ecosystem health assessment were used. Potential uses of pool water were also evaluated based on measured water quality parameters. Heavy metals in water and sediment were determined using Flame Atomic Absorption Spectrometry. Results revealed that salinisation, acidification and heavy metals were exported from a mining tailings dam to the stream. The degree of contamination of pool water by heavy metals dictated water uses. Heavy metal concentrations imposed water use restrictions for aquatic life in a pool which directly received discharge from the mine tailings dam. The average heavy metal concentrations in sediments were lower than the standard shale values. Sediment quality guidelines and pollution indices showed that the stream was not polluted with heavy metals, thus posed no potential ecological risk. Continuous monitoring of tailings discharge and wash off is important to safeguard aquatic ecosystem and public health.
Spiders were studied as predators of the invertebrate epigeic fauna inhabiting forest and grassland ecosystems variously polluted with metals. The response of detoxifying enzymes in adult male and female spiders (a wolf spider Pardosa lugubris and a funnel weaver Agelena labyrinthica) was compared using material collected at five sites in forest and grassland transects along the metal pollution gradient. Carbo- xylesterases, acetylcholinesterase and metal concentrations were assayed in spiders during the season. In both species at the most polluted sites of forest and meadow transects CarE activity was higher. These ani­mals effectively used quantitative compensatory strategy against pollutants, which demands extra energy. Comparisons between species showed a better adaptation to pollutants in the ground wolf spiders. In these animals from polluted meadows AChE activity was also higher than that in agelenids.
The pollution of aquatic ecosystems by heavy metals has assumed serious proportions due to their toxicity and accumulative behavior. River dams are especially at risk of contamination by different contaminants from anthropogenic sources including heavy metals since change of the sediment regime often occurs. The largest hydropower dam and reservoir system along the entire Danube, the Iron Gate, is located at the Djerdap Gorge (117 km long) in Serbia and Montenegro. In order to determine the degree of pollution of the Iron Gate by heavy metals, composite sediment samples were collected from seven reaches of the river from Smederevo (river-km 1112) upstream from the Iron Gate dam to Radujevac (river-km 851) downstream from the gorge. The concentrations of As, Cd, Cr, Cu, Fe, Pb, Mn, Hg, Ni and Zn were determined in the sediments. The lowest heavy metal concentrations were measured around river-km 854, downstream from the gorge. The data from this study were compared with data obtained 20 years ago in the same area. It was found that the range of mean concentrations over the entire gorge of Fe, Mn, Ni, Zn, Cu, Cr and Cd increased by 46.6% (Zn at the site Tekija) to 156.2% (Ni at the site Veliko Gradiste). Decreases in concentrations were observed for Hg and Pb. Metal levels in the sediments did not exceed Dutch intervention values, but were higher than the target values for Ni, Zn, Cu, Cr and especially for Cd, indicating contamination not sufficiently high to require remediation/intervention, but not excluding risk to the ecosystem.
This isoenzymatic and cytogenetic study has shown significant differences in genetic composition between two groups of Pinus sylvestris trees: tolerant and sensitive to heavy metal pollution. Total and mean numbers of alleles and genotypes per locus were higher in the pollution-sensitive group of trees, but heterozygosity (H₀) was lower in this group. Fixation index (F) indicates that trees tolerant for pollution were in the Hardy-Weinberg equilibrium, while the sensitive group had a significant excess of homozygosity. Cytological analyses demonstrated numerous aberrations of chromosomes in meristematic root tissue of seedlings developed from seeds collected from trees in the polluted area. The aberrations included chromosome bridges and stickiness, laggards, retarded and forward chromosomes, and their fragments. The mitotic index was markedly lower in this group of seedlings, as compared to the control. Both isoenzymatic and cytological analyses showed a significant influence of heavy metal ions on the genetic structure of the Pinus sylvestris population.
Short sediment cores (30 cm length) were taken along a transect of the Gdansk Basin from the mouth of the Vistula River out into the Baltic Sea in June 1996. The chemistry and mineralogy of surficial and buried sediments were determined and Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were analyzed in total and in fractions using a sequential extraction procedure. The bulk and clay mineralogy of the sediments were determined by XRD and SEM. The concentrations of some of the trace metals in sediments are above pre-anthropogenic background. In particular, the surficial samples are substantially enriched in Cu, Pb and Zn, suggesting an anthropogenic origin. The concentrations of Cu, Pb and Zn range from 21-71 ^g-g"1, 56-210 ^g-g"1 and 21-83 ^g-g-1, respectively. Unexpectedly, the concentrations of trace metals increase seawards within the Gdańsk Basin. The forms of binding are different for each metal. Cobalt, Cr and Fe are mainly associated with the residual mineral fraction of the sediment, although in samples with high Fe concentrations there is a significant correlation with organic compounds. In contrast, Mn, Ni, Pb and Zn are predominantly associ­ated with oxides and the organic fractions, with a significant percentage associated with the carbonate and exchangeable cation fractions, whilst Cu is mainly bound with the organic fraction.
This study measured levels of cadmium, chromium, copper, nickel, lead, and zinc in fruits of Capsicum annuum L., Phaseolus vulgaris L., and Solanum melongena L. during the 2007 vegetation period, to determine levels of metal pollution in Istanbul Province. Plant and soil samples were collected from six sites in Istanbul (Brook Coast area, inner city, industrial area, suburban, roadside, and rural – control – areas). Unwashed and washed leaf and soil samples were analyzed using inductively coupled plasma optical emission spectrometry. The highest and lowest values were as follows: Cd (0.28-0.89 µg·g⁻¹), Cr (5.33⁻¹4.04 µg·g⁻¹), Cu (1.47-5.19 µg·g⁻¹), Ni (3.06⁻¹3.65 µg·g⁻¹), Pb (29.28-86.20 µg·g⁻¹), and Zn (3.70-5.74 µg·g⁻¹). The unwashed samples were more contaminated than the washed samples. Contamination was higher in the vegetables grown in industrial areas and along roadsides. The overall metal concentration pattern in vegetables was Pb > Cr > Ni > Zn > Cu > Cd.
Litovelské Pomoraví Protected Landscape Area (Czech Republic) was chosen as the study area of heavy metal pollution (Zn, Ni, Cu, Pb, Cd). Assessment of heavy metal concentration in the soil was performed at eleven sites along the water stream in the alluvial plain (Morava river) and compared with concentration in selected plant tissues. Heavy metal concentration in two plant species (Urtica dioica L., Taraxacum sp.) and soils were detected by atomic absorption spectrophotometry (AAS). The correlation between heavy-metal concentrations in plant tissues (roots, leaves, stems) and in soils was tested and the ability of plants for heavy-metals indication in the alluvial plain landscape ecosystem was observed. Differences in correlation and ability to accumulate heavy metals were found not only between species and heavy metals but also among various plant tissues. Taraxacum sp. as a whole closely followed concentration of Zn, Cu, Pb and Cd and seems to be much more suitable as bioindicator than Urtica dioica L. Nevertheless, there are plant parts of both species with better response to adequate metal. Some plant tissues of both species provide ambiguous results, which was discussed in terms of living forms, growth strategy and genotypic differences.
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