31 resultados para Heavy Ions


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The marine environment near Karachi, particularly the Baba channel, Chari Kundi channel and Manora channel have been found contaminated with industrial effluents discharged by Malir and Lyari rivers, since they carry a high concentration of toxic heavy metals viz. Pb, Zn, Cu and Mn emanating from the industrial area and are received and discharged by the Lyari river. Out of 60 seawater samples collected from the above mentioned areas, Pb was present in 55 samples and Zn in 58 samples. The concentration of Pb was between 0.04 and 59.2ppm and the concentration of Zn was between 0.05 and 1.9ppm. Similarly all the 60 sludge samples collected from Lyari outfall and its adjoining area have been found to contain Pb and Zn in alarmingly high concentratios, which for Pb was between 15.4 and 3209.9ppm while for Zn was between 87 and 111.3ppm. Cu and Mn were also found in all the above samples.

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The median lethal concentrations (LC50) of two Isopoda species exposed to each tested metal (Cu. Co, Cd and Zn) in static tests for different exposure periods are quite variable depending on the tested metal The LC50 values for Sphaeroma walkeri after 24 hours exposure to Cu and Co were estimated graphically to be 11.20 and 7.00 mg/1 respectively. The correspoding values for Cirolana bovina exposed to Cu, Co, Cd and Zn were 3.60, 11.0, 3.80 and 4.80 mg/1 respectively. For 2 days the LC50 of S. walkeri exposed to Cd was 5.60 mg/l, but it was 10.10 mg/l for 3 days exposure to Zn. After prolonged exposure the LC50 values decreased proportionally with the exposure duration of the test the percentages of surviving animals demonstrated a progressive decrease with increasing concentratins as a main factor from the analysis of variance (ANOV A). The sensitivity of adult S. walkeri exposed to the four heavy metals for different exposure times ranked: Cd>Co>Zn>Cu. Cirolana bovina appeared to be more sensitive to Cu. Cd and Zn than to Co. Species in order of increasing sensitivity is C. bovina more than S. walker.

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A study to measure the heavy metal pollution level in the sediment of coastal and offshore area indicates that high concentration of heavy metals were found around Manora channel and eastern coast of Karachi. In comparison with coastal areas, relatively low concentration of heavy metals was recorded in the offshore area. The result shows that sewage and industrial wastes are the main source of heavy metal pollution in the coastal area. The concentration of heavy metals in the sediments is as follows: Chromium 10.4-33.69, nickel 13.3-47.6, lead 10.0-39.04, cadmium 0.08-0.21, zinc 7.4-73.2 and copper 9.44-18.56 mg/kg. In the offshore areas strong correlation was observed between copper and organic carbon, and calcium carbonate and cadmium. In the shore area such correlation has been recorded among nickel, chromium, zinc, and chromium and copper. The Karachi. coast is viewed as moderately polluted when compared to other continental coastal areas.

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The coastal water of the metropolitan city of Mumbai has deteriorated due to the indiscriminate discharge of untreated sewage and industrial waste in huge quantities. Mahim creek is one such locality surrounded by a large number of industrial units discharging heavy metals. The accumulation of the heavy metals Cu, Cd, Zn and Pb in finfishes (Coilia dussumeri, Lepturacanthus savala, Harpodon nehereus and Johnieops elongates) from this locality along with that in the sediment was studied. The rate of accumulation of Cu was high compared to Cd, Zn and Pb. A gradual increase in the bioaccumulation of heavy metals was noticed in fishes with increase in average body weight and length, perhaps due to biomagnification. A declining trend in concentration of heavy metals horizontally from inshore to offshore was observed in these fishes.

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Aspartate aminotransferase (E.C. 2.6.1.1.) from the skeletal muscle of fresh water fish Cirrhina mrigala has been purified 40 fold by ammonium sulphate fractionation, adsorption on alumina Csub(8) gel and chromatography using DEAE-cellulose column and the properties of the purified enzyme studied. The pH optimum of the enzyme is 7.8. The Km value of aspartic acid and 2-oxoglutaric acid are found to be 2.8 x 10sub(-3) M and 1.0 x 10sub(-4) M respectively. The activity of enzyme is inhibited by p-chloromercurybenzoate, hydroxylamine hydrochloride and sodium cyanide. The inhibition by pchloromercurybenzoate is reversed by reduced glutathione, B-mercaptoethanol and cysteine. Dicarboxylic acids such as maleic acid, malic acid and succinic acid inhibit the enzyme activity. The enzyme is not activated by any of the metal ions tested and heavy metal ions such as mercury and silver strongly inhibit the enzyme activity.

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Data obtained from investigations which had been carried out during 1998-1999 in the waters of South Vietnam indicate that concentrations of Fe and Zn were usually higher than permissible limits. In the East South Vietnam waters, Fe concentration varied from 77 to 4450g/l (mean 1045g/l) and Zn concentration varied from 7.24 to 74.1g/l (mean 26.7g/l), Pollution coefficients of the two metals were 10.4 and 2.7 respectively. In the Gulf of Thailand, variation range of Fe was 133-850g/l (mean 318g/l) and of Zn was 4.8-167.8g/l (mean 23.46g/l); corresponding pollution coefficients were 3.2 and 2.3. Mn, Cu, As had mean concentrations lower than permissible limits. In the East South Vietnam waters, variation range for Mn was 9.0-444.6g/l (mean 57.0g/l), for Cu was 1.0- 20.3g/l (mean 3.1g/l) and for As was 1.0-10.5 g/l (mean 3.7 g/l). In the Gulf of Thailand, Mn concentration varied from 1.2 to 410.5g/l (mean 19.1g/l), Cu concentration varied from 1.2 to 14.7g/l (mean 3.7g/l), variation range of As concentration was 1.0-13.3g/l with the mean value was 3.6g/l. Scarce data relating to Hg, Cd, Pb showed that their concentrations in the East South Vietnam waters were negligible (usually < 1.0g/l).

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The contents of the heavy metals Fe, Zn, Cu, Mn, Pb, Cd and As were examined in the liver, heart, gills, kidney and muscles of the fish Clarias gariepinus from Eko-Ende dam in Ikirun, the capital of Ifelodun Local Government of Osun State, Nigeria. C. gariepinus is the fish of choice and the most demanded in the southwest of Nigeria. The highest metal concentrations were in the liver and the gills while the lowest was in the muscles. The general deceasing order of metal accumulation in the organs was Fe > Zn > Cu > Mn > Cd. Lead and arsenic were not detected in any organ. The values were of lower concentrations than found in many other dams and rivers in Nigeria and some other countries. The values were also lower than the FAO/WHO recommended maximum limits in fish samples, making the fish to be safe and not of any hazards for the consumers.

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While carp themselves may destroy carp eggs by sucking from outside the happa, destruction in the absence of carp also occurs. During observations of the effect of electrical field on developing carp eggs it was seen that the egg membrane ruptured prematurely under certain potential differences. In natural waters and mud potential differences occur in the presence of high concentrations of certain salts compared with the internal concentration. Temperature and pH fluctuations following strong sun or heavy rain accelerates the diffusion of ions along side water through the egg membrane. The egg cells expand rapidly and the embryos were rapidly dropped.

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Studies on the distribution of heavy metals like copper, cadmium, zinc, lead and mercury in deep sea prawns Pandalus borealis in the Oslofjord region showed that those collected from inner and middle fjord contained higher levels of heavy metals than those from the outer fjord. Their content in the edible portions, viz., tail muscle, was less compared to other organs. In terms of metal concentration copper and zinc are present in significant quantities in Pandalus borealis.

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Perna viridis exposed to different concentrations of copper and zinc for varying periods and then the rate of filtration estimated under metal free culture conditions. The concentrations under which the animals were maintained before the experiments were 0.025 to 0.150 p.p.m. of zinc and 0.005 to 0.08 p.p.m. of copper.

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The concentrations and distribution of particulate and dissolved heavy metals, viz: Cu, Zn, Pb, Cd, Fe and Mn have been determined seasonally during 2003 in water samples collected from the Suez Canal. The presented data clarifies that the metals exhibited clear differences in their distribution between particulate and dissolved forms. The concentration of particulate heavy metals ranged between 0.09-3.13, 0.57-15.02, 0.18-3.87, 0.02-0.73, 2.74-49.62 and 0.15-5.08 µg/L for Cu, Zn, Pb, Cd, Fe and Mn, respectively. In the same respect, these values for dissolved forms were 0.28-4.12, 0.57-9.08, 0.27-2.50, 0.02-1.24, 1.94-42.50 and 0.11-3.65 µg/L. The concentrations of particulate metals viz: Zn, Pb, Cd, Fe and Mn were high was compared to the dissolved forms. Dissolved copper, rather than particulate, showed the highest percentage of total copper. The particulate forms of Pb, Cd, Fe and Mn always had higher concentrations than the dissolved forms during the course of study except in the summer season. The northern part of the Suez Canal at Port Said showed mean concentrations of particulate and dissolved Cu=1.43 and 2.10, Zn=8.61 and 3.17, Pb=1.72 and 1.23, Cd=0.35 and 0.35, Fe= 23.49 and 15.83 and Mn=2.09 and 1.82 µg/L. These high concentrations may be attributed to the greater activities, particularly loading and unloading operations at Port Said harbour s industrial effluents and domestic drainage of Port Said city. In contrast, the Sinai side could be considered as reference site, as it was almost clean, i.e., without harmful outfalls, where Cu=0.16 and 0.56, Zn=2.14 and 0.94, Pb=6.29 and 3.44, Cd=0.055 and 0.088, Fe=6.29 and 3.44 and Mn=0.56 and 0.26 µg/L for particulate and dissolved metals respectively.

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This work focuses on four marine sites in the Mediterranean Sea around the Nile Delta, Egypt. Surface water samples were collected seasonally during 2003. The concentrations of some heavy metals in dissolved form (Fe, Mn, Zn, Cu, Ni and Pb) are evaluated. The levels of heavy metals in the coastal waters were 11.92-30.4512µglˉ¹ for Fe; 5.79-17.36 µglˉ¹ for Zn; 0.30-0.83µglˉ¹ for Cu; 0.51-2.90µglˉ¹ for Ni and 0.53-10.31µglˉ¹ for Pb. These are compared, with sites in the estuaries and outlets of the Nile Delta. Fe (19.72-60.33µglˉ¹); Mn (12.63-35.60µglˉ¹); Zn (2.67-22.00); Cu (0.56-1.67µglˉ¹); Ni (1.43-3.73µglˉ¹); Pb (1.72-59.7µglˉ¹). The results showed a remarkable decrease in the concentrations of different heavy metals with increased salinity. Comparing the present data with the minimal risk concentration reported by WQC, the distribution of heavy metals was significantly lower in coastal sea water of the Mediterranean Sea off Egypt. The study indicated also that the average contents of Ni and Pb are slightly high in the area of water exchange than those reported by WQC.

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Biochemical ecotoxicology and biomarkers using are a new sciences that are used for biomonitoring in aquatic environment. Biomonitoring plays a vital role in strategies to identify, assess, and control contaminants. On the other hands in recent year's attention to polycyclic Aromatic Hydrocarbons (PAHs) and heavy metals increased in aquatic environments because of their carcinogenic and mutagenic properties combined with their nearly ubiquitous distribution in depositional environments by oil pollution or industrial waste waters. The present research aimed to assess PAHs and Ni, V levels in surface sediments and bivalves (Anodonta cygnea)and the effects of PAHs and heavy metals (Ni,V) on the hemocyte of the Anodonta cygnea were investigated in 2 stations (Mahrozeh, Selke in Anzali Lagoon, North of Iran). Samples were collected during at 2 different periods of the year, Dry and rain seasons, (June & September) and to confirm our first observations, Cage station is added. The bivalves hemocytes were monitored for membrane injury by NRR methods (neutral red retention assay). Heavy metal (Ni, V) concentrations were determined by Atomic Absorption in Anodonta cygnea and the sediments in Anzali Lagoon. The vanadium concentration in bivalves and sediments was ND(not detect )-0.4231 μg/g and 1.4381-306.9603 μg/g dry weight respectively. Nickel concentration in bivalves and sediments was 0.0231-1.3351, 0.4024-19.3561 μg/g dry weight respectively. PAHs concentrations were determined by GC-Mass in Anodonta cygnea and the sediments. Average concentration of PAHs is 115-373.788 ng/g dry weight in bivalves and average concentration of PAHs is 34.85-1339.839 ng/g dry weight in sediments. Bioaccumulation sediments factor(BASF) is high about PAHs (>1) and BASF is low for Ni, V (<1) . Internal Damage mechanisms of bivalves hemocytes (cell mortality, dye leakage, decreased membrane stability, are observed (Lowe Methods). Statistical analysis was used to explore the relationship between altered cellular and above contaminants. There are power and negative correlations between PAHs and NRR method for hemocytes in Anodonta cygnea (P<0.0005), but good correlation is not observed between Ni, V and NRR method for hemocytes in every time. This research indicates that the NRR assay is a useful screening technique able to discriminate polluted sites and at first we announce that Anodonta cygnea hemocytes are efficient biomarker for PAHs pollutants in fresh water.

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Biological studies and heavy metal (Ni, v, Fe, Pb,Cd) determination in liver, gonad and muscle of Scomberomorus commerson were carried out from Oct 2006 to Sept 2007 in Hormozgan coastal waters. 599 Samples were gutted for reproduction and nutrition studies, fork length and weight were measured to nearest cm and g respectively. Meanwhile 40 samples were also investigated for heavy metal studies. All specimens were collected from two major landing sites (Bandar Lengeh & Bandar Abbas). Minimums & maximum fork length & weight were 29, 128 cm & 235 and 15350 g respectively.Isometric growth was shown according to our study and b was estimated 2.9 (overall), 2.91(male) & 2.89 (female). The average relative gut length was 0.52± 0.007 and it was determined that S. commerson is a carnivorous. More than 99 percent of gut content was different teleost fishes. Gastro somatic index had two peaks in Nov & Jan (before spawning) and with a decreased trend in July, the spawning period. Occurrence of empty stomach was estimated % 65.77. Maximum amount of condition factor was in Dec. Spawning season was started from June. The average of Absolute & relative fecundity (to weight unit) was 1217149±179315 and 178.2±15.58 respectively. Lm50% was estimated 75 cm for females. Sex ratio was 0.97: 1 (male: female). Chi- Square test showed no significant difference (p>0.05). Maximum amount of hepatosomatic index was estimated in March.Metal concentrations were determined using either Flame Atomic Absorption Spectroscopy (for Fe) or Graphite Furnace Atomic Absorption Spectroscopy (for Pb,Cd,Ni and V). The mean concentration (μg/g dry weight)of Pb,Cd,Ni,V and Fe in the liver were 0.0309, 0.0268, 0.0672, 0.0077, 2.5159 in the gonad 0.0440 ,0.0295, 0.1096, 0.0000, 1.4449 and in the muscle 0.0244, 0.0324, 0.0656, 0.0128, 1.6138 respectively. The maximum metal concentrations were below the maximum permissible limits for human consumption recommended by the USEPA, WHO and the UK. The results of Kendall's Tau-b correlation coefficient were as follows: The Liver tissue: There were significant positive linear relationships between accumulation of V, Fe, and Pb with Fork length, Pb and Fe with weight, GSI with Pb, Cd, V and 109 Fe, and a negative linear relationships between HSI with accumulation of V and Fe, Fork length, weight and GSI. The Gonad tissue: There were significant positive linear relationships between GSI with accumulation of Pb, Cd, Fe, Fork length and weight, a negative linear relationship between HSI with Fork length, weight and GSI. The Muscle tissue: There were significant positive linear relationships between accumulations of V, Fe with Fork length and weight factors and as well as GSI with Cd, V, Fe, Pb, Fork length and weight,a negative linear relationship between HSI with Fork length, weight, Cd, Fe and GSI. The results of Mann-Whitney U tests (P≤0.05) show that there were significant differences between summer and autumn from heavy metal contents in the studied tissues point of view. The only exceptions were for Ni in the liver, gonads and muscle and as well as there were significant differences between male and female from heavy metal contents in the studied tissues. The only exceptions were for Pb in muscle, Ni in liver, gonad and muscle, V in muscle, and Cd and Fe in gonads.

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In the present study, intestinal helminth parasite fauna of 398 specimens of three species of kilkas, C. engrauliformis (N= 92), C. grimmi (N= 136) and C. cultriventris (N= 170) from Babolsar harbor were investigated. Five parasite species were found including: Corynosoma strumosum (Acanthocephala), Pronoprymna ventricosa (Trematoda), Contracaecum sp. (Nematoda), Raphidascaris sp. (Nematoda) and Anisakis sp. (Nematoda). The highest prevalence and abundance were observed in C. strumosum and P. ventricosa. The prevalence and abundance of C. strumosum in C. grimmi was significantly higher than C. engrauliformis. The prevalence and abundance of P. ventricosa in C. cultriventris was significantly higher than C. engrauliformis. The prevalence, mean intensity and mean abundance of the parasites were compared according to the sex, length group and season also effect of parasite on host growth parameters was considered. The diversity, equability, similarity, species richness, dominance Indices and specificity indices of helminth parasites of the three host species were studied. Also the lead and cadmium concentrations in the intestine, muscle, liver, kidney and gonad of kilkas and their parasites C. strumosum and P. ventricosa were measured and compared. The results revealed that lead and cadmium concentrations in C. strumosum and P. ventricosa were significantly higher than kidney, liver, intestine, gonad and muscle. The lead and cadmium concentrations of the parasites were compared according to the sex, parasitism and season.