5 resultados para Lead mines and mining

em Aquatic Commons


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Studies were carried out to assess some macro and trace elements of mineral composition of the male and female Heterobranchus bidorsalis adults exposed to graded concentrations (1.00-8.00m/L-1) of Bonny-light crude oil (BLCO). The experiment was monitored for 4 days (toxicity) and 42days (recovery) periods. Significant decreases (P < 0.05)in the sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), phosphorus (P), zinc (Zn), iron (Fe), vanadium (Va), lead (Pb) and manganese (Mn) contents of the male H. bidorsalis corresponded with the increasing concentrations of BLCO. In contrast, the female fishes recorded significant increases (P < 0.05) in the values of the above elements in their tissues as the concentrations of BLCO increased. Furthermore, the values of Na, K, Mg, Ca, P, Zn, Fe, Va, Pb and Mn recorded in the male fishes where generally lower than those of their female counterparts and the control fish. Increased values of these elements were also recorded during the recovery periods (days 14, 28 and 42) of this study in the magnitudes of 15% at day 14, 20% at day 28 and 20% at day 42. This implied that the removal of crude oil stress during this period improved the quantity of these minerals deposited in the fish tissues. The highest percent proportion of Zn and the lowest proportion of Pb recorded in both male and female H. bidorsalis adults agreed with the report of other workers for other fish species. KEYWORDS: Heterobranchus bidorsalis, Mineral composition, Bonny-light crude oil, Toxicity, Recovery.

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The impact of Petrochemical Special Economic Zone (PETZONE) activities on the health status of Jafari Creek was studied by assessing the changes in macroinvertebrate assemblages in nine sites during September 2006- January 2008. Furthermore to evaluate the ecological status of the Jafari Creek the WFD indices (i.e. AMBI, M-AMBI) were used. The relationship between spatial pattern of macro invertebrate assemblages and ambient factors (i.e. water temperature, salinity, pH, dissolved oxygen, turbidity, electrical conductivity, total dissolved solid, total hardness, total nitrogen, ammonia, total phosphorous, chemical oxygen demand, biological oxygen demand, sediment grain size distribution, sediment organic content, heavy metals contents) was measured. Background Enrichment indices, Contamination factor and Contamination degree, were used to assess the health status in the study area based on Nickel, Lead, Cadmium and Mercury contents of the sediments. The macrobenthic communities had a low diversity and were dominated by opportunistic taxa, and the AMBI and M-AMBI indices need to be calibrated before using in Persian Gulf and its coastal waters. The BIO-ENV analysis identified pH, dissolved oxygen, TDS, and the total organic content of sediments as the major environmental variables influencing the infaunal pattern. This suggests that management should attempt to ensure minimal disturbance to environmental variables underlying the spatial variation in macroinvertebrate assemblages. Background Enrichment indices showed that the health of Jafari Creek has declined over time due to the constant discharge of heavy metals to the Creek system. Furthermore WQS index shows that the quality condition of the water column in Jafari Creek, regard to the calculated number (3) is week. These indices also identified a significant degree of pollution in the study area. The decrease in the ecological potential of Jafari Creek was best highlighted by the alteration in macrobenthic assemblages.

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There are various tools for monitoring the concentration of pollutants on aquatic ecosystems. Today these studies are based on biological monitoring and biomarkers. The aim of this study was to measure the concentration of the acetylcholinesterase (AChE), glutathione S-transferase and catalase as biomarkers of heavy metal contamination in pearl oyster Pinctada radiata and their mechanism in aquatic ecosystems. Heavy metals lead, cadmium and nickel were measured in soft tissue and studied stations in four seasons. Samples were collected seasonally in Lavan stations, Hendurabi and Nakhilo (in the northern Persian Gulf) from spring 2013 to winter of that year by scuba diving. Pearl oysters are divided according to their shells size; shells separated from soft tissues and were transferred to the laboratory for analysis of heavy metals and enzymes. Moopam standard method for were used for measuring the concentration of heavy metals and for analyzing tissue concentrations of glutathione S-transferase in Clam the method recommended by Habig et al in 1974 were used. For measuring acetylcholinesterase Ellman method were used. Catalase contamination in pearl oyster in the supernatant obtained from the study based on the method homogeate soft tissue of mussels (Abei, 1974) was evaluated. The results showed that the concentration of lead has significant difference in sediments station, the concentration of lead in Lavan is significantly higher than the other two stations, This could be due to the movement of tanker, boats and floating refueling and with a considerable amount of wastewater containing oil and Petroleum into the water, and also due to precipitation and industrial discharges the lead in the region is increasing, land-disposed sewage sludge, has large concentrations of lead. Compare the results of this study with standards related and other similar studies at the regional and international level showed that pollutant concentration of heavy metals in all cases significantly less than all the standards and guide values associated. And also compared to other world research results have been far less than others, Being Less of the conclusion given in this research according that nickel is one of the indicators of oil pollution in the study area and emissions have been relatively low of oil. The concentration of acetylcholinesterase at several stations, in large and small sizes and in the seasons had no significant difference. Variations of catalase, and glutathione S-transferase were almost similar to each other and parameters, station and seasons were significantly different in the concentrations of these enzymes. The effects and interaction between various parameters indicate that following parameters has impact on the concentration of catalase and glutathione S-transferase. Stations; Seasonal changes in antioxidant enzymes related to (assuming a constant in salinity and oxygen) to age, reproductive cycle, availability of food and water temperature. With increasing temperature at warm season, antioxidant enzymes were increase, with increasing temperature and abundance of food in the environment the amount of antioxidant enzymes may increase. The presence of the enzyme concentration may indicate that the higher levels of the enzyme to eliminate ROS activities to be any healthier situation. At the time of gonads maturation and spawning season catalase activity increases. This study also indicates that catalase was significantly higher in the warm season. Due to low pollutants of heavy metals in the study area, a lower level of contaminants were observed in shellfish tissue incidents of international standards and strong correlation between the amount of heavy metal contamination in pearl oyster tissue and enzymes was not observed. Therefore, we can say that the pearl oyster remains in a healthy condition and the amount of enzyme is normal.

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Lake Victoria shoreline in Jinja Municipality has four urban wetlands of Kirinya West/Loco, Kirinya East/Walukuba, Masese and Budumbuli which have undergone major changes during the past fifty years due to increased human activities. Amongst these activities is the continuous inflow of agricultural run-off, industrial and municipal wastewater. A significant increase in nutrient loads of Nitrogen and Phosphorus from the catchment area continues to enhance eutrophication of Lake Victoria. Pollution from point sources (Industrial plants and NWSC Kirinya final maturation pond) into Jinja’s urban wetlands were therefore studied using a simplified material flux analysis methodology to identify the active elements and estimate the pollution loads due to Nitrogen, Phosphorus, Carbon (nutrients), Chromium, Copper, Lead, Nickel and Manganese metals.

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A number of ocean science fields have profitted, either directly or indirectly from satellite remote sensing, including physical, biological and geological oceanography. User oriented applications include fishing, shipping, offshore drilling and mining, coastal engineering and coastal hydrology. Following a brief account of the technology involved, areas in oceanography benefitting from satellite information are detailed. Examples are given of satellite data applications to marine resources.