Concentrations Of Zn In Water Research Articles

The effect of using jug-type water filters on selected metals concentration in tap water – a case study

ABSTRACT In this study, the effect of the filtration process on Na, K, Mg, Ca, Fe and Zn concentration in water, using filters from one of the leading European manufacturers, was investigated. The increase in Na (up to 300%) and K concentration (up to 320%) at the beginning of jug filter usage was reported. A decrease in Ca, Fe and Zn concentration was observed. Standard filters remove 80–90% of Mg from tap water at the beginning of the usage, while magnesium-enriching ones slightly increase its concentration – from around 8 to 12–25 mg/L. Significant changes in the filter's operating characteristics were also observed for other studied elements as they wore out. Using Mg-enriching filters can increase magnesium intake from 4–5 to 6–15% of the recommended daily dose from water consumption. The results were also discussed regarding the amounts of macroelements found in commercially available bottled water. The magnesium concentration in tap water after filtration through magnesium-enriching filters was lower compared to bottled mineral waters. The authors note a scope for the development of water filter production technology, in particular, the need to develop filters that more efficiently enrich water with magnesium and do not increase sodium concentration.

Determination of heavy metals concentration in water and sediment of river donga, Taraba state

This research was carried out to ascertain the heavy metals concentrations in water and sediments from River Donga upstream and downstream was investigated for a period of three months (October to December). The Result showed heavy metals concentrations were higher in sediments compare to water during the study period while downstream values were generally higher compare to upstream. Result for mean concentration of heavy metals variations in water and sediment varied significant (p>0.05) based on the two sampling locations upstream and downstream. The heavy metals concentration in water and sediments was examined using atomic absorption spectrophometer (AAS) Bulk scientific Model 210VGP. Concentrations ranking profile was found to be Zn >Ni>Pb >Cr>Cd. The maximum mean concentration of Zn recorded in the sediment was 0.700 mg/kg while the lowest value of 0.029mg/kg was recorded for Pb at the two locations while for water value (0.200 mg/l) were observed for Zn, Ni, and Cr in the months of October November and December respectively. The lowest value of 0.014mg/1 at both locations was recorded for Cr. Data for Cr, Ni, Pb. Pb were generally low throughout the study period. Zn concentrations in water at the sampled locations (upstream and downstream) throughout the study periods showed no significant difference (p>0.05). However, Cd, Cr, Pb and Ni show variations (p

Essential and non-essential metals in three lowland rivers of temperate South America (Argentina): Distribution and accumulation

BackgroundGeographic distribution of essential metals on earth is largely uneven. Therefore, regional specific approaches to assess metal contents in freshwater ecosystems are mandatory. Cd, Cu, Cr, Pb, Ni, Mn and Zn concentrations were measured in water, sediments and fish tocharacterize the partitioning of these essential and non-essential metals in three river ecosystems of the Pampean Plain==. MethodsWater, sediment and eight fish species were collected at three rivers from the Pampean Plain. After sample-specific pretreatments, Cd, Cr, Cu, Mn, Ni, Pb and Zn concentrations in water, sediment and muscle were determined in triplicate by Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). Contamination (Hakanson´s index) and bioconcentration factors were calculated to assess the degree of contamination and the relationship between the matrices, while the target hazard quotient was estimated to explore the risk to human health from fish consumption. ResultsWater metal concentration was below detection limit in all sampled rivers. Sediments were mostly enriched by Mn (186–474 mg kg−1) followed by Zn (36.8–40.3 mg kg−1), whereas in fish, the situation was the opposite, suggesting different biogeochemical pathways and uneven bioaccumulation of these elements. The largest concentrations for all explored metals were invariably recorded in fish from the Sauce Grande River, although only Cd, Cu and Ni in sediments were highest at this site. Indeed, the bioconcentration factor showed that Cd and Zn are actively accumulated by almost all species in all sampled rivers. The Targeted Hazard Quotient based on the muscle metal concentration tissue of the edible fish species (Odontesthes bonariensis) was less than 1. ConclusionNone metal seemed to pose a significant risk for humans. In some sites biota-sediment concentration factors of Cd and Zn and muscle Cd, Cr, Ni, Zn and Pb levels were highest in the silurid Pimelodella laticeps, suggesting that it may be used as a sentinel species for biomonitoring programs in Neotropical fish assemblages.

Interrelation of Zinc and Cadmium in the Biological Samples of Indoor and Outdoor Workers of Five Zonal Areas of Coal Mining Field

Coal mining is still one of the most tough, nasty, and dangerous jobs in the world, with more fatalities than any other. The present study assessed zinc (Zn) and cadmium (Cd) in scalp hair and blood samples of 270 coal mining field employees, working in Hyderabad, Pakistan, aged 18-55 years. The scalp hair and blood samples of age-matched healthy volunteers (n= 70) were examined for chosen elements for a comparison analysis. For understudied metals, environmental samples (soil, water, and coal) from coal mining fields and nonindustrial areas were investigated. The Zn levels in the scalp hair and blood samples of coal mining male exposed workers were found to be lower, in the range of {88.9- 118; 100- 133 and#181;g/g} and {3.32- 4.41; 3.33- 6.04 mg/l)}, respectively than the referent subjects {224-237; 209-221} and#181;g/g and {6.82-7.82; 6.60-7.42 mg/l}, respectively. Whilst, the Cd concentrations in the scalp hair and blood samples different five zones of indoor and out-door coal mining field exposed workers were found to be higher, in the range of {10.1- 16.9; 9.65- 16.9} and {8.89- 12.65; 8.96- 11.7} and#181;g/l, respectively than the biological samples of two age groups (18-35) and (36- 55) years referent subjects {3.45-4.45; 4.02-5.32} and#181;g/g and {3.25-3.72; 3.82-4.10 and#181;g/l}, respectively. Serum, hemoglobin, hematocrit, red blood count, and creatinine clearance counts were significantly lower in mining filed workers than in referents (p0.001), whereas erythrocyte sedimentation rate and N-acetyl- beta-glucosaminidase levels were significantly higher in workers than in referents (p0.001).The Zn concentration in water and soil samples of mining field were found to be within the WHO recommended values, whilst Zn concentration in coal samples of mining field was in between 15.5- 20.6 and#181;g/g. Whilst, Cd levels in water and soil samples of mining field were found above the WHO recommended values, whilst Cd content in coal samples of mining field was in between 0.52- 0.75 and#181;g/g. The findings indicate that immediate action is required to improve ventilation and hygiene measures within factories, mines, and other work environments.

Uptake and accumulation of heavy metals by water body and Azolla filiculoides in the Anzali wetland

The Anzali international wetland is a valuable habitat to a wide variety of aquatic flora and fauna. This wetland ecosystem is being threatened due to various pollutants particularly the heavy metals discharging from different point and non-point sources. Concentration of various heavy metals (Cr, Pb, Hg, Cu, Zn, Cd, Ag and Ti) was examined in the water body and Azolla filiculoides (an exotic fern in the Anzali wetland). The samples regarding water and A. filiculoides were randomly carried out in three parts of the wetland (eastern, central and western parts) in May 2015. After preparing and digesting the samples, the concentration of the heavy metals was measured using ICP OES method. The obtained results showed that the concentration of Zn in water and A. filiculoides samples was higher than other heavy meals in all parts of the wetland (p < 0.05). Overall, concentration of the heavy metals was significantly higher in the eastern part of the wetland than other two sampling locations (p < 0.05). Also with comparing the concentration of the heavy metals in water and A. filiculoides, it was found that all examined metals (except Cd and Ag) in A. filiculoides had significantly higher concentration than water sample, while Cd and Ag in water and A. filiculoides did not have a significant difference with each other. Based on the results, it can be concluded that A. filiculoides can effectively absorb Cr, Pb, Zn, Hg, Cu, Cd, Ag and Ti so that it might be used as a valuable species for the bioremediation and the removal of heavy metals from the wetland.

Assessment of the transfer of heavy metals in seawater, sediment, biota samples and determination the baseline tissue concentrations of metals in marine organisms.

The majority of tissue-specific environmental quality standards (EQSs) considering metal tolerance are prior to the chemical-specific EQSs in aquatic organisms. However, metal baseline levels in marine organisms were very scarce. We explored the correlation between Hg, Cd, Pb, Cu, and Zn concentrations in water or sediments and those metal concentrations in marine organisms (crustacean, mollusc, and fish) by generalized additive models (GAMs) and executed a meta-analysis of Hg, Cd, Pb, Cu, and Zn contents in those three organisms by implementing cumulative frequency distribution analysis of individual metal distribution in a heavy metal-contaminated semi-enclosed Bay, China. Results showed that the average contents of Hg, Cd, Pb, Cu, and Zn were 0.042±0.01, 0.38±0.22, 1.72±0.65, 3.61±1.01, and 16.08±6.33 μg/L in water; 0.064±0.02, 0.42±0.04, 20.54±7.76, 28.97±3.90, and 96.74±35.11 μg/g dw in sediment; and 0.0049±0.0028, 0.52±0.28, 0.24±0.15, 11.05±6.95, and 21.12±4.47 μg/g dw in crustacean, 0.015±0.0087, 0.24±0.17, 0.08±0.02, 0.37±0.35, and 10.62±6.79 μg/g dw in mollusc; and 0.0038±0.0028, 0.065±0.05, 0.32±0.19, 2.01±0.59, and 16.04±4.97 μg/g dw in fish. The mercury content in mollusc presented a negative correlation with mercury content in sediment, while the content of other metals (Cd, Pb, Cu, and Zn) in organisms showed positive correlations with the content of those metals in water or sediment. We further obtained tissue-baseline-C5% in crustacean, mollusc, and fish which were 1.191, 3.341, and 0.014 μg/g dw for Cu; 0.013, 0.072, and 0.033 μg/g dw for Cd, 0.015, 0.027, and 0.052 μg/g dw for Pb; 9.515, 14.422, and 0.056 μg/g dw for Zn; and 0.0009, 0.004, and 0.0035 μg/g dw for Hg, respectively. However, there were no obvious relationships of the 4d-NOEC in laboratory toxicity tests with C5%, as well as C50% and 4d-LC50 or tolerance index a for Cu, Cd, Pb, Zn, and Hg in organisms. Our results pointed out the controversy of laboratory sensitive species toxicity results for deriving chemical-specific EQSs with field studies. We advocated to set up the metal concentration baselines in aquatic organisms and further served the tissue-specific EQSs, which are essential basis for geochemical recordings, bio-monitoring, and semi-enclosed bay management in the world.

Effect of redox gradients on Cu and Zn concentrations in water of Blanakan River, West Java

Metal concentrations in water threat adjacent ecosystems due to the potential of metal mobilization and the subsequent uptake into water. Here, contents of heavy metals Cu and Zn were determined for river waters. We used factorial analysis (FA) to determine the metal contents in relation to environmental factors such as redox potential (Eh), dissolved oxygen (DO), pH, salinity, temperature and turbidity in the Blanakan river. The Zn was ranging from 0.44 to 2.13 mg/L. The FA categorized Zn with salinity and temperature. Meanwhile, the Cu was ranging from 0.02 to 0.05 mg/L. The FA categorized Cu with Eh, turbidity, DO and pH. Such discrepancy in metal concentrations highlighted that redox gradient has more effects on Cu than Zn. Respectively, decrease of Eh from -38 to -41 mV can increase the Cu up to 0.05 mg/L. Correlation of Eh with Cu contents indicating that Cu was influenced by terrestrial inputs. Conversely, correlation of temperature and salinity with Zn contents indicating that Zn was influenced by aquatic inputs.

The effect of lead (Pb) and zinc (Zn) contamination on aquatic insect community composition and metamorphosis

Metal contamination of freshwater ecosystems is a great threat to aquatic insect communities. In the past, focus has been on the toxic effects on the insect larvae, despite emerging evidence showing that negative effects can occur during metamorphosis to adults. There is therefore a risk that traditional studies on insect larvae would underestimate effect from metals. In this study, we investigated the effect of lead (Pb) and zinc (Zn) on aquatic insect abundance, including metamorphosis and adult emergence at 9 lakes, near an abandoned Pb/Zn mine, with different Pb and Zn concentrations in sediment and water. Further, differences in response to metal contamination among taxa, and potential community composition changes, were also investigated. Total insect abundance was not affected by metal contamination, but Zn had a negative effect on metamorphosis and proportionally less adults emerged compared to larval abundance when the bioavailable Zn concentration in water increased. The opposite pattern was found for bioavailable Pb (negative effect on larvae but not on adult emergence). All studied insect groups had similar response to metal contamination, and no change in community structure towards dominance of more tolerant taxa was observed. Our study shows that it is important to include metamorphosis when metal toxicity is evaluated in aquatic insects, and that metals can have opposite and contradicting effects. Thus, although combined cocktail effects of metal mixtures are important to assess, effects of individual metals can be underestimated.

Effect of heavy metals from an electronic waste open dumping area on the cytotoxicity of climbing perch (Anabas testudineus)

ABSTRACT Abnormal chromosomes in climbing perch (Anabas testudineus) from a reservoir near an electronic waste (e-waste) open dumping area compared with reference area were investigated. The Cd, Pb, Cr, Cu, Mn, Ni and Zn concentrations in water and sediment did not exceed the standard limit of Thailand. The Cd, Pb and Cr concentrations in A. testudineus from the e-waste area exceeded the food standard. The heavy metal concentrations in the A. testudineus samples from the e-waste and the reference areas were significantly different (p < 0.05), except for Mn. There were five types of abnormal chromosomes: centromere gap, deletion, fragmentation, single chromatid gap and single chromatid decomposition. The percentages of abnormal chromosomes in the A. testudineus cells from the e-waste and the reference areas were significantly different (p < 0.05). The results indicated that Cd, Pb and Cr concentrations from the e-waste area could induce the occurrence of abnormal chromosomes in A. testudineus.

Detection of Zn in water using novel functionalised planar microwave sensors

Metal pollution in aquatic environments has attracted global attention. Current methods are not able to monitor water quality in-situ at low-cost. This paper reports on a novel approach for detecting changes in the concentration of zinc in water using electrical and a microwave sensor method, adopting two planar sensors: one was functionalised with a screen-printed β-Bi2O3 based coating, while the other was uncoated. Results show that both electrical and the microwave sensor responses were dependent on the presence and concentration of Zn in water with R2 = 0.93–0.99. The functionalised sensor with a 60 μm thick β-Bi2O3 based film offers improved performance compared with both uncoated and functionalised sensors with 40 µm thick coating for detecting the changes of Zn concentrations in water for low levels (100 and 500 µg/L). This novel sensing system could be a cost-effective alternative to the current offline methods.

Investigation of Copper and Zinc on the Content in Haizhou Bay and in Platycephalus Indicus

The contents of heavy metals copper (Cu) and zinc (Zn) in water, sediment, fish skin and flesh of fish in Haizhou Bay were investigated twice in 2017 and 2018. It was found that the contents of Cu and Zn increased year by year. In addition, the contents of Cu and Zn in water and sediment decreased with the increase of offshore distance, indicating that the source of importation was terrestrial, which was consistent with the literature reports. Although Cu and Zn in water belong to class one of seawater, according to MA¼ller’s accumulation index, Cu in sediments of some sampling sites has been moderately polluted and Zn has also been slightly polluted. Although the content of Cu and Zn in skin and flesh of Platycephalus indicus does not exceed the food standard limit, its higher enrichment coefficient increased with the increase of Cu and Zn concentration in water. If the heavy copper and zinc sources imported into Haizhou Bay are not regulated, it may also cause food safety problems for fish.

Effects of dissolved oxygen, salinity, nitrogen and phosphorus on the release of heavy metals from coastal sediments

Great amounts of nutrients discharged into the urbanized coastal areas, which are continuously subject to violently anthropogenic metal contamination, will result in eutrophication and hypoxic episode. In order to study the effects of dissolved oxygen (DO), salinity, nitrogen and phosphorus on the release of six metals including Zn, Pb, Cd, Cu, As and Cr from coastal sediments, a series of 60-days microcosm experiments consisting of sediments and seawater were conducted. Severe hypoxia could result in the enhanced peak values of Pb, Cd, Cu and Cr concentrations in the overlying water. A higher level of water salinity could elevate the peak value of As concentration in water column, and a higher level of nitrogen could increase the peak value of Zn concentration in water. The exchange fluxes demonstrated that the diffusion from the sediments was a dominant process during the first 10 days, However, a relative equilibrium of adsorption and precipitation in the sediment-water interface reached during the later periods. In addition, the bioavailability of the studied metals in sediments was elevated under severe hypoxia, or a high level of water salinity, or high levels of nitrogen and phosphorus. The results of linear regression analysis suggested that higher metal bioavailability in sediments could facilitate the metal release, but the process could be restrained by the higher aqueous phosphorus due to the precipitation of metal phosphates.

Geostatistical study of spatial correlations of lead and zinc concentration in urban reservoir. Study case Czerniakowskie Lake, Warsaw, Poland

AbstractThe article presents detailed geostatistical analysis of spatial distribution of lead and zinc concentration in water, suspension and bottom sediments of large, urban lake exposed to intensive anthropogenic pressure within a large city. Systematic chemical measurements were performed at eleven cross-sections located along Czerniakowskie Lake, the largest lake in Warsaw, the capital of Poland. During the summer, the lake is used as a public bathing area, therefore, to better evaluate human impacts, field measurements were carried out in high-use seasons. It was found that the spatial distributions of aqueous lead and zinc differ during the summer and autumn. In summer several Pb and Zn hot-spots were observed, while during autumn spatial distributions of Pb and Zn were rather homogenous throughout the entire lake. Large seasonal differences in spatial distributions of Pb and Zn were found in bottom sediments. Autumn concentrations of both heavy metals were ten times higher in comparison with summer values.Clear cross-correlations of Pb and Zn concentrations in water, suspension and bottom sediments suggest that both Pb and Zn came to Czerniakowskie Lake from the same source.

The Role of Sedimentation on Waters Edge and Analysis Pb and Zn Concentration in Water from Sentani Lake, Jayapura-Papua

We have conducted research on the role of sediment on the waters edge and content analysis of metal concentrations of lead (Pb), zinc (Zn) in the water of Sentani Lake in Jayapura, Papua Province. The experiment was conducted in April 2013. The study was conducted to determine the role of lake sediments on water quality, sediment characteristics and metal analysis has been analyzed in the laboratory to determine the concentration of Pb and Zn in the sediment. Metal analysis using Atomic Absorption Spectrophotometry (AAS) instrumentation. Sediment characteristics that have analysis, namely physical and chemical parameters are bulk density, density, porosity, water content, texture, pH, DO, colors and others. Sediment sampling locations are Ifale, estuary, Yahim beach and Yoboy with each location in depth of 0-5 cm, 5-10 cm and 10-15 cm vertically. The results showed that at each sampling site and every sediment depths showed highly significant influence on the metal content of Pb and Zn. In general, the deeper the sediment content of Pb and Zn showed different results. Average content of heavy metals (Pb and Zn) in sediments at each location that are Ifale at 27.37 mg/Kg and 35.04 mg/Kg, estuary of 15.37 mg/Kg and Pb is 28.01 mg/Kg, Yahim beach of 3.83 mg/Kg and 33.50 mg/Kg, while the location of Yoboy of 6.69 mg/Kg and 34.60 mg/Kg. Concentration of Pb (3.83 to 27.37 mg/Kg) and Zn (6.69 to 35.04 mg/Kg) in sediments is lower than the standard quality of heavy metals in sediments (EPA Region V a ) is 40 mg/Kg for Pb and 90 mg/Kg for Zn metals, therefore concentrations of Pb and Zn in sediments at four locations of Sentani lake is still below the quality standard so that the levels of Pb and Zn in the sediment is not contaminated. The existence of Sentani lake sediments act as a reservoir heavy metal and not as a source of pollutants to the water quality in the Sentani lake.

Contaminants in surface water and sediments near the Tynagh silver mine site, County Galway, Ireland

A former silver mine in Tynagh, Co. Galway, Ireland is one of the most contaminated mine sites in Europe with maximum concentrations of Zn, As, Pb, Mn, Ni, Cu, and Cd far exceeding guideline values for water and sediment. The aims of this research were to 1) further assess the contamination, particularly metals, in surface water and sediment around the site, and 2) determine if the contamination has increased 10years after the Environmental Protection Agency Ireland (EPAI) identified off-site contamination. Site pH is alkaline to neutral because CaCO3-rich sediment and rock material buffer the exposed acid generating sulphide-rich ore. When this study was compared to the previous EPAI study conducted 10years earlier, it appeared that further weathering of exposed surface sediment had increased concentrations of As and other potentially toxic elements. Water samples from the tailings ponds and adjacent Barnacullia Stream had concentrations of Al, Cd, Mn, Zn and Pb above guideline values. Lead and Zn concentrations from the tailings pond sediment were 16 and 5 times higher, respectively, than concentrations reported 10years earlier. Pb and Zn levels in most sediment samples exceeded the Expert Group (EGS) guidelines of 1000 and 5000mg/kg, respectively. Arsenic concentrations were as high as 6238mg/kg in the tailings ponds sediment, which is 62 and 862 times greater than the EGS and Canadian Soil Quality Guidelines (CSQG), respectively. Cadmium, Cu, Fe, Mn, Pb and Zn concentrations in water and sediment were above guideline values downstream of the site. Additionally, Fe, Mn and organic matter (OM) were strongly correlated and correlated to Zn, Pb, As, Cd, Cu and Ni in stream sediment. Therefore, the nearby Barnacullia Stream is also a significant pathway for contaminant transport to downstream areas. Further rehabilitation of the site may decrease the contamination around the area.

Trace metals in water and sediment from a tropical watershed subject to anthropogenic inputs

Sixteen stations were established to assess water and sediment quality throughout the Caura/Tacarigua watershed. Samples were analyzed for Cd, Cr, Cu, Fe, Ni, Pb, Zn and Hg using atomic absorption spectrometry during the dry and wet seasons of 2005. In the dry season, Pb and Zn exceeded sediment quality guidelines for the protection of aquatic life. Highest concentrations of all metals were recorded at one station subject to a range of anthropogenic inputs in the lower watershed area; Cu exceeded the water quality guideline at this station. In the wet season, Zn exceeded the SQG at one station located south of residential areas in the lower watershed area and highest concentrations of Cr and Pb were recorded at that station. Metals in water were detected primarily at stations in the lower watershed area. Wet season concentrations of Zn in water were significantly higher than corresponding dry season concentrations. Likely sources of trace metals in the watershed include effluent from a light industrial estate, sewage/domestic waste from non-functioning sewage treatment plants and pit latrines, agricultural and urban runoff. Results of this study show that management strategies using an integrated approach are needed to minimize trace metal pollution within the watershed.

Environmental concentrations and bioaccumulations of cadmium and zinc in coastal watersheds along the Chinese Northern Bohai and Yellow Seas

Cadmium (Cd) and zinc (Zn) in surface water, sediment, carp, and crab samples collected from upstream and downstream regions of coastal watersheds along the Chinese Northern Bohai and Yellow Seas were analyzed to provide a comprehensive understanding and assessment of their environmental concentrations and bioaccumulations. The results showed that downstream waters contaminated with Zn would have adverse effects on aquatic organisms. Although nearly all sediments were contaminated with Cd due to human activities, little potential existed for Cd toxicity in sediment-dwelling fauna. Concentrations of Cd and Zn in most water, sediment, carp, and crab were less than published values. The downstream carp and crabs had higher mean bioaccumulation factors and biota-sediment accumulation factors for Cd but lower mean biota-sediment accumulation factors for Zn than the upstream carp and crabs. Based on the relationships among Cd and Zn concentrations in water, sediment, and biota, the authors conclude that Cd and Zn in crabs primarily derived from sediment exposure. Although Cd and Zn in water and sediment originated from some of the same sources, the sources of Cd or Zn in water were likely different from those in sediment.

Biomarkers responses in muscle of Senegal sole (Solea senegalensis) from a heavy metals and PAHs polluted estuary

The biochemical responses in muscle, such as the enzymatic activities of acetylcholinesterase, lactate dehydrogenase and isocitrate dehydrogenase, were studied in sole (Solea senegalensis) collected in Huelva estuary (SW Spain), in the vicinity of a petrochemical and mining industry. The sampling sites showed different type and degree of pollution. The results demonstrated significant differences in muscle activities of AChE and IDH in Odiel and Tinto Rivers compared to control fish. LDH activity did not show any difference between sampling sites. Significant correlations were established between some biomarkers and heavy metals: AChE was correlated with Pb, Cd and Cu concentrations in water; IDH activity was correlated with Cd and Cu concentrations in water and As, Pb and Cd concentrations in sediments; LDH activity was correlated with As and Zn concentration in water and Cd concentration in sediment. Only one correlation was established between the biomarkers analysed and the concentrations of PAHs: benzo(b)fluoranthene concentration in sediment and IDH.

Effect of Land Use on Coastal Water and Perna viridis at Johor Straits, Malaysia

In this study, land use effect on river water quality and its subsequent impact on Johor Strait coastal water and green mussel, Perna viridis cultivated at the strait near the fast growing city of Johor Bahru, is investigated. Over the years, changes in land use and increased discharge of domestic, agricultural and industrial waste into the coastal water has severely impaired the water condition and threatened the profitable green mussel aquacu lture activity. Cu and Zn concentrations in water were found to be higher at sampling points closer to Johor Bahr u city while Sungai Pendas and Sungai Melayu which are less develop yielded lower pollutants concentration. The heavy metal concentrations (in mg/L) are between 0.18 to 0.38 for Zn and 3.24 to 3.44 for Cu. Coastal water recorded Zn concentratio n (in mg/L) of 0.03 to 0.05 and Cu concentration of 0.25 to 0.33 while green mussels recorded (in μg/g) 18.24 to 40.01 of Zn and 24.29 to 92.52 of Cu.

Influence of Salinity in the Bioavailability of Zn in Sediments of the Gulf of Cádiz (Spain)

This study assesses the effect of salinity in bioavailability and toxicity of Zn by means of laboratory bioassays by observing contamination in both sediment and water, accumulation of Zn in biological tissues, and histopathological damage in the gills and guts tissues of Ruditapes philippinarum clams, which were exposed to different types of sediments from the Gulf of Cadiz (SW Spain) as well as two dilutions of toxic mud coming from an accidental mining spill. With this objective, the coefficients of distribution (K D) for Zn between overlying water and sediments were calculated, the histopathological frequencies in the tissues of the gills and guts of clams were determined, and the biota-sediment bioaccumulation factors as well as the bioaccumulation factors were quantified in the different stations. Results showed that the greatest histopathological damages appeared when the salinity values decreased. Statistical results showed that salinity was inversely correlated with histopathological damage (p < 0.01) for the lesion index for gills. The most outstanding results were observed in the two dilutions of toxic mud (0.3% and 7.9%) at a salinity value of 10. Salinity was inversely correlated with the concentration of Zn in biological tissues (p < 0.05) and inversely correlated with the concentration of Zn in water and sediment. Zn mobilization to the overlying water is produced when salinity values decrease.