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1.
The leather industry, besides being a major contributorto the Indian national economy, is unfortunately alsoone of the major polluters. The present articlediscusses the influence of the wastes on thephysicochemical characteristics of the Ganga water andsediments. Two sampling sites have been chosen atKanpur, the first before and the second after thepoint where tanneries are located. The samephysicochemical parameters which have been determinedin the wastes have been monitored at these two sitesfor two seasons. The results reveal that mostparameters increase as the river traverses betweenthese two points. The increase in values of parameterssuch as BOD, COD, Cl-, and total solids could bedue to the domestic wastes just as much as to thetannery wastes. Phenols and sulfides, can also comefrom other sources, but their probability of comingfrom tanneries is higher. However, chromium is oneparameter which can primarily be identified tooriginate from the tanneries. The speciation of thesediments for chromium reveals that the leakage ofchromium into the Ganga is taking place at the secondsite. There is almost a ten fold increase in chromiumat the second site as compared to the first. At thefirst site the surface chromium is primarily in theresidual fraction while at the second site it is inthe Fe–Mn oxide fractions.  相似文献   

2.
Surface sediment samples collected from the Salina Cruz Bay in the last twenty years, were analyzed for the total available trace elements (Cr, Cu, Fe, Pb, Ni, V, and Zn) to evaluate metal contamination due to possible anthropogenic inputs. Normalization of metals to iron and fine-grained fraction (< 63 μm) indicated relatively high enrichment factors for lead during the last two decades. Sediment Quality Guidelines suggest that lead must be considered as a chemical of potential concern in the marine and estuarine ecosystem. Concentration levels of lead ranged from 5–124 μg/g, while Ni and V below 70 and 30 μg/g, respectively. Geoaccumulation and enrichment factors for the rest of elements show comparable values to those reported for sites with similar activities in the world. Spatial distribution suggests that in addition to harbor activities, a transboundary source for Pb must account for the observed trends.  相似文献   

3.
This study reports the concentration levels and distribution pattern of the persistent organochlorine pesticide (OCPs) residues in the water and bed-sediments of the Gomti River collected seasonally over a period of 2 years. The water and bed-sediment samples were collected from eight different sites and analyzed for aldrin, dieldrin, endrin, HCB, HCH isomers, DDT isomers/metabolites, endosulfan isomers (alpha and beta), endosulfan sulfate, heptachlor and its metabolites, alpha-chlordane, gamma-chlordane and methoxychlor. In the river water and sediments SigmaOCPs residues ranged between 2.16 and 567.49 ng l(-1) and 0.92 and 813.59 ng g(-1), respectively. The results, further, suggested that source of DDT contamination is from the aged and weathered agricultural soils with signature of recently used DDT in the river catchments. To assess any adverse effect of OCPs contamination on river's biological component, the threshold effect level (TEL) was used. The results revealed that bed-sediments of the Gomti River are contaminated with lindane, endrin, heptachlor epoxides and DDT, particularly at site-4 and may contribute to sediment toxicity in the freshwater ecosystem of the river.  相似文献   

4.
Heavy metals in honey are of interest not only for quality control, but also for determination environmental contamination. The objective of this work was to determine distribution of the levels of selected heavy metals. Levels of copper (Cu), cadmium (Cd), manganese (Mn), Iron (Fe), magnesium (Mg) and nickel (Ni) in honey samples (21) in Kahramanmaraş region were determined by atomic absorption spectrometer (AAS). The mean values for Cu, Cd, Mn, Fe, and Mg were 0.01, 0.32, 0.03, 0.36 and 10.45 ppm, respectively. Nickel was not detected in honey samples. Kahramanmaraş honey samples were not free of heavy metals but the levels of them were found well below the permitted levels. The results suggested that honey may be useful for assessing the presence of environmental contaminants.  相似文献   

5.
The levels of mercury, cadmium, lead, copper, nickel, zinc and iron were determined in samples of liver, kidney, skeletal muscle, heart, lungs and hair of moose (N = 67), reindeer (N = 45), brown bear (N = 18), wild boar (N = 10) and squirrel (N = 18) shot in Karelia from 1989 to 1991 during regular hunting. The highest heavy-metal concentrations were found in livers, kidney, lungs and hair samples. The samples of muscle contained lowest levels of these elements. The tissues of moose, reindeer and brown bear were contaminated with heavy metals to a greatest extent. Lowest levels of toxicants were recorded in wild boar. Results indicate a widespread presence of heavy metal in the environment and in wildlife, which may be linked to acid precipitation. There was no evidence of these elements accumulated to toxic levels, but Karelian public have been informed that the eating of moose liver and kidney would probably result in their exceeding WHO standard weekly intake limit for cadmium.  相似文献   

6.
This study evaluates the spatial patterns of land occupation and their relationship to water quality in the Cuiabá River watershed, one of the main affluents of the Pantanal floodplain. The impact of farming and other land occupation forms were studied using a three year time series. Monitoring included 15 parameters at 21 stations with a total of 1266 different samples. Ten stations along the Cuiabá River were ordinated by Principal Component Analysis (PCA). For an exploratory analysis in the spatial domain, sub-basins of the Cuiabá watershed were classified according to mean concentrations of selected water quality parameters. Supervised classification of digital Landsat ETM imagery and standard GIS techniques were applied to parameterize land use and occupation according to a watershed scale. Redundancy Analysis (RDA) was then used to evaluate impacts of environmental and socio-economic factors on water quality.A Cuiabá headwater station only shows slightly elevated total coliform counts and concentrations of nutrients in the river after it passes regions of extensive cattle farming. After the confluence with the Manso River, nutrient and COD concentrations increase significantly, receiving loads from sub-basins under intensive agricultural land use, with mean annual concentrations up to 1.74 mg/L of total nitrogen (Kjedahl). Sub-watersheds with intensive fishing culture activities were shown to have significant impact on nitrogen concentrations, reaching mean concentrations of 2.66 mg/L of total nitrogen in the affluents. Most serious biological and chemical water pollution can be observed at stream outlets in the urban agglomeration of Cuiabá/Várzea Grande. Affluent pollution is reflected in the water quality of the Cuiabá River: subsequent monitoring stations in the urban area are ordinated on a gradient of increasing degradation of chemical and biological water quality. The auto-depuration capacity of the Cuiabá River is intact, but elevated concentrations of Phosphorous and Chemical Oxygen Demand can be observed as far away as the Pantanal floodplain, about 120 km downstream from the urban agglomeration.  相似文献   

7.
Sediment traps were deployed in the three major basins of Lake Erie, and the central (Mississauga) basin of Lake Ontario, and refurbished seasonally over the period 2000–2002. In Lake Ontario, sediment down-flux rates and corresponding contaminant down-flux rates were highest in winter during periods of unstratified thermal conditions, and generally increased with depth due to the influence of resuspended bottom sediments during all sampling periods. Lake Ontario suspended sediments exhibited the highest concentrations of metals; concentrations of mercury and lead frequently exceeded guideline values for bottom sediments. Contaminant levels in Lake Ontario suspended sediments were similar to concentrations in bottom sediments in the same area. There was a spatial trend toward higher suspended sediment metals concentrations from the eastern basin to the western basin of Lake Erie, which is similar to the trend in bottom sediment contamination. In the eastern basin of Lake Erie, which is the deepest area of the lake, there was no trend in down-flux rate with depth in 2001; however, down-flux rates increased with depth in 2002. Suspended sediments in the western basin of Lake Erie were determined to be largely resuspended bottom sediments; all western basin samples collected in the study exceeded the guideline value for mercury (0.486 μg/g).  相似文献   

8.
Analysis of summer and winter vegetable samples during 2002–2003 for pesticidal contamination was carried out on Gas Chromatograph-Electron Capture Detector with capillary columns. The contamination levels of winter vegetables (average concentration of 4.57, 6.80 and 5.47 ppb respectively for Lindane, Endosulphan and DDT) were found to be slightly higher than the summer vegetables (average concentration of 4.47, 3.14 and 2.82 ppb respectively for Lindane, Endosulphan and DDT). The concentration of these organochlorine pesticides in summer and winter vegetables were well below the established tolerances but continuous consumption of such vegetables even with moderate contamination level can accumulate in the receptor's body and may lead to chronic effects that could be fatal.  相似文献   

9.
Highways and main roads are a potential source of contamination for the surrounding environment. High traffic rates result in elevated heavy metal concentrations in road runoff, soil and water seepage, which has attracted much attention in the recent past. Nonetheless, investigations of pollutants in roadside soils are still a subject of major interest due to the rapid development of traffic systems and increasing traffic all over the world. The accumulation of the heavy metals Pb, Cd, Cu and Zn in soils along the oldest federal highway of the world has been studied by sampling a roadside transect of 125 by 10?m. In addition, heavy metal concentrations of Pb, Cd, Zn, Cu, Ni and Cr in soil solutions from different distances (2.5, 5 and 10?m) from the hard shoulder of the highway and from three soil depths (10, 30, and 50?cm) were investigated. The results show that heavy metal concentrations are up to 20 times increased compared to the geochemical background levels and a reference site of 800-m distance from the roadside. Soil matrix concentrations in the topsoil (0-10?cm) mostly exceeded the precautionary values of the German Federal Soil Protection and Contamination Ordinance (BBodSchV). The concentrations of Cd, Pb and Zn in the soil matrix tended to decrease with distance from the roadside edge, whereas the concentrations in the soil solution increased at a distance of 10?m onwards due to a lower soil pH. Because of both high pH values and a high sorption capacity of the soils, soil solution concentrations seldom exceeded the trigger values of the German Federal Soil Protection and Contamination Ordinance (BBodSchV) for transferring soil solution to groundwater.  相似文献   

10.
The Republican River Basin of Colorado,Nebraska, and Kansas lies in a valley which contains PierreShale as part of its geological substrata. Selenium is anindigenous constituent in the shale and is readily leached intosurrounding groundwater. The Basin is heavily irrigated throughthe pumping of groundwater, some of which is selenium-contaminated, onto fields in agricultural production. Water,sediment, benthic invertebrates, and/or fish were collected from46 sites in the Basin and were analyzed for selenium to determinethe potential for food-chain bioaccumulation, dietary toxicity,and reproductive effects of selenium in biota. Resultingselenium concentrations were compared to published guidelines orbiological effects thresholds. Water from 38% of the sites (n = 18) contained selenium concentrations exceeding 5 g L-1, which is reported to be a high hazard for selenium accumulation into the planktonic food chain. An additional 12 sites (26% of the sites) contained selenium in water between 3–5 g L-1, constituting a moderate hazard. Selenium concentrations in sedimentindicated little to no hazard for selenium accumulation fromsediments into the benthic food chain. Ninety-five percent ofbenthic invertebrates collected exhibited selenium concentrationsexceeding 3 g g-1, a level reported as potentially lethal to fish and birds that consume them. Seventy-five percent of fish collected in 1997, 90% in 1998, and 64% in 1999 exceeded 4 g g-1selenium, indicating a high potential for toxicity andreproductive effects. However, examination of weight profilesof various species of collected individual fish suggestedsuccessful recruitment in spite of selenium concentrations thatexceeded published biological effects thresholds for health andreproductive success. This finding suggested that universalapplication of published guidelines for selenium may beinappropriate or at least may need refinement for systems similarto the Republican River Basin. Additional research is needed todetermine the true impact of selenium on fish and wildliferesources in the Basin.  相似文献   

11.
The Chillán River in Central Chile plays a fundamental role in local society, as a source of irrigation and drinking water, and as a sink for urban wastewater. In order to characterize the spatial and temporal variability of surface water quality in the watershed, a Water Quality Index (WQI) was calculated from nine physicochemical parameters, periodically measured at 18 sampling sites (January–November 2000). The results indicated a good water quality in the upper and middle parts of the watershed. Downstream of the City of Chillán, water quality conditions were critical during the dry season, mainly due to the effects of the urban wastewater discharge. On the basis of the results from a Principal Component Analysis (PCA), modifications were introduced into the original WQI to reduce the costs associated with its implementation. WQIDIR2 and WQIDIR, which are both based on a laboratory analysis (Chemical Oxygen Demand) and three (pH, temperature and conductivity), respectively, four field measurements (pH, temperature, conductivity and Dissolved Oxygen), adequately reproduce the most important spatial and temporal variations observed with the original index. They are proposed as useful tools for monitoring global water quality trends in this and other, similar agricultural watersheds in the Chilean Central Valley. Possibilities and limitations for the application of the used methodology to watersheds in other parts of the world are discussed.  相似文献   

12.
A study was carried out in Pettavaithalai area to evaluate the current status of physico-chemical contaminants and their sources in groundwater. Groundwater samples collected from pettavaithalai area in 15 different stations were analyzed every alternative months over a period of two years from August 2000 to June 2002. A sugar mill is situated at the heart of the study area. Three profiles (profile A, B and C) were selected based on the direction in which the sugar mill effluent flows. In each profile five samples were collected from five different station at a regular distance of about 1 Km. The physico-chemical parameters such as pH, EC TDS, TH, NO3, SO4, PO4, Na, K, Ca, Mg, DO, BOD and COD have been analyzed. The results showed that among the three profiles, many of the estimated physico-chemical parameters of profile C were very high when compared to profile B and A which indicates the poor quality of the groundwater around this area.  相似文献   

13.
Sediments constitute a pollutant trap and have proven to be an efficient tool to identify environmental impacts. Sediments are considered a very important means to assess the level of contamination of water bodies because of their ability to accumulate metals and organic. The anthropogenic inputs of sewage, with or without prior treatment, in aquatic environments, affect the geochemical composition of sediment. In addition, the sediment adsorbs hydrophobic compounds found in feces, such as the fecal sterols. The granulometric and geochemical composition of the sediment of Barigüi River-Brazil was investigated. The results show that silt and clay dominate the granulometric composition of the sediments. The geochemical composition of sediments showed high concentrations of phosphorus and nitrogen. The Redfield ratios confirm the inputs of phosphorus and nitrogen. The TOC/N ratio was used to identify the source of pollution. N/TP ratios were found between 1.0 and 3.5. Clearly, an input of phosphorus, sewage is the most acceptable source, following the historic profile of the Barigüi River. High concentration of nitrogen phosphorus labels the area to be polluted by sewage. To confirm the sewage pollution, adsorbed fecal sterols in sediments were investigated. The concentration of total sterols was found between 0.86 and 304.58 μg g???1. Two distinguished scenario was found, one severely polluted and another slightly polluted. The highest concentrations of total fecal sterols were associated with sediment whose geochemical composition showed higher levels of TOC, as well as higher proportions of silt and clay. Also, epicoprostanol, a coprostanol isomer, was used as an indicator of the level of treatment or age of the fecal matter because it is formed during the treatment of wastewater and sludge digestion. If the treatment of sludge takes a long time, epicoprostanol can form from cholesterol, and relative proportions of those compounds may be used as an indicator of the presence of untreated sewage in the sediments. The epicoprostanol was found in the range between 0.02 and 9.71 μg g???1; concentration of up to 0.015 μg g???1 represents situations where there is strong contamination by sewage. All sites investigated showed a concentration of epicoprostanol higher than the value adopted as threshold. The lower concentration of epicoprostanol found for all sites is consistent with the high concentration found for coprostanol, and this is typical for untreated sewage.  相似文献   

14.
Systematic measurements of both Tributyltin (TBT) and Dibutyltin (DBT) in sediments along different locations in the inner zone of Bahía Blanca estuary were done. Two samples were taken near the main dry dock facility, at Puerto Belgrano naval base, in Argentina. TBT concentrations from non-detected to 170.3 ng Sn g−1 were measured in the inner region of the estuary, and higher one of 3,288 ng Sn g−1 near the dry dock at Puerto Belgrano. DBT values ranging between non-detected and 75.2 ng Sn g−1 were obtained along the principal channel, but extreme concentration of 1,645 ng Sn g−1 was measured at Puerto Belgrano. These values show that this estuary is affected by organotin pollution, mainly in areas of heavy shipyard activities.  相似文献   

15.
Lake Ontario and St. Lawrence River (LOSL) wetland bird abundance and diversity are greatly influenced by lake and river hydrology. Our study used an interdisciplinary ecosystem approach, blending avian and plant ecology, ecohydraulic, statistical ecology and modelling to evaluate potential impacts of water level fluctuations on indicator species representative of the wetland breeding bird assemblages in the entire LOSL freshwater system. Multi-year (2000–2003) bird surveys captured bird distribution and density in wetland habitats under varying degrees of water inandation, depth and fluctuation. Analyses revealed strong associations between estimated breeding pair densities and plant communities, water depth, and degree of water level fluctuation during the breeding season for a suite of wetland bird species using marsh, wet meadow, shrub swamp and treed swamp habitats. These quantitative associations were used to develop wetland bird performance indicators for use in a LOSL water regulation review study. Several bird species also nest at or near the water surface and are thus vulnerable to nest flooding or stranding. Changes to the seasonal hydrology of Lake Ontario and St. Lawrence River that result in an increased frequency or magnitude of these nest failure events may have a significant impact on regional population sustainability. Long term nest record databases were analyzed to create nesting flooding and stranding probability equations based on water level increases and decreases during the breeding season. These species-specific nesting relationships were incorporated into a reproduction index.Many breeding bird species were strongly associated with specific wetland plant communities. Predicted habitat suitability, as measured by estimated breeding pair density, can also change significantly within a specific wetland plant community based solely on changes in water depth during the breeding season. Three indicator species, Black Tern, Least Bittern and Virginia Rail were selected as key environmental performance indicators for alternate regulation plan comparisons.Water regulation criteria should be such that the long term diversity and abundance of wetland plant communities and frequency of spring flooding in marsh habitats during breeding are not reduced. Magnitude and frequency of water level change during the nesting season (May–July) can also adversely impact reproductive success of many wetland bird species. As such, regulation criteria that increase the seasonal magnitude and frequency of water level change may be detrimental to the long term viability of certain regional breeding bird populations.  相似文献   

16.
An assessment on heavy metal (Al, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn) accumulation by seven seagrass species of Lakshadweep group of islands was carried out using multivariate statistical tools like principal component analysis (PCA) and cluster analysis (CA). Among all the metals, Mg and Al were determined in higher concentration in all the seagrasses, and their values varied with respect to different seagrass species. The concentration of the four toxic heavy metals (Cd, Pb, Zn and Cu) was found higher in all the seagrasses when compared with the background values of seagrasses from Flores Sea, Indonesia. The contamination factor of these four heavy metals ranged as Cd (1.97–12.5), Cu (0.73–4.40), Pb (2.3–8.89) and Zn (1.27–2.787). In general, the Pollution Load Index (PLI) calculated was found to be maximum for Halophila decipiens (58.2). Results revealed that Halophila decipiens is a strong accumulator of heavy metals, followed by Halodule uninervis and Halodule pinifolia, among all the tested seagrasses. Interestingly, the small-leaved seagrasses were found to be efficient in heavy metal accumulation than the large-leaved seagrass species. Thus, seagrasses can better be used for biomonitoring, and seagrasses can be used as the heavy metal sink as the biomass take usually long term to get remineralize in nature.  相似文献   

17.
Ashtamudi estuary, situated on the southwest coast of India, is enormously affected by anthropogenic interventions. Physicochemical quality of water and sedimentological features of the estuary are evaluated during monsoon and nonmonsoon seasons to elucidate its quality variations and to link the same with existing environmental scenario. The whole data has been factorized using principal component analysis for extracting the total variability and linear relationships existing among a set of different physicochemical parameters of the backwater system. In PCA, high loadings were obtained for conductivity, salinity, fluoride, calcium, magnesium, sulfate, boron, and pH. The results were revealed that all the physicochemical processes depend upon seasonal fluctuation of freshwater input and seawater intrusion. Wide spatial concentration fluctuations of organic carbon and iron in bottom sediment have been noticed and both constituents reveal good correlation with sediment texture. The results showed high deterioration of the physicochemical quality of water during nonmonsoon season with respect to monsoon season.  相似文献   

18.
A combined semi-distributed hydrological model (CASCADE/QUESTOR) is used to evaluate the steady-state that may be achieved after changes in land-use or management and to explore what additional factors need to be considered in representing catchment processes. Two rural headwater catchments of the River Derwent (North Yorkshire, UK) were studied where significant change in land-use occurred in the 1990s and the early 2000s. Much larger increases in mean nitrate concentration (55%) were observed in the catchment with significant groundwater influence (Pickering Beck) compared with the surface water-dominated catchment (13% increase). The increases in Pickering Beck were considerably greater than could be explained by the model in terms of land-use change. Consequently, the study serves to focus attention on the long-term increases in nitrate concentration reported in major UK aquifers and the ongoing and chronic impact this trend is likely to be having on surface water concentrations. For river environments, where groundwater is a source, such trends will mask the impact of measures proposed to reduce the risk of nitrate leaching from agricultural land. Model estimates of within-channel losses account for 15–40% of nitrate entering rivers.  相似文献   

19.
The Yamaska River drainage basin in Quebec, Canada, is intensively farmed and heavily polluted with poorly treated domestic and industrial wastes. We investigated the responses of the resident and colonizing components of the benthic macroinvertebrate community to municipal/industrial versus agricultural pollution in the basin, and evaluated the performances of seven diversity and biotic indices for assessing water quality. Samples of riffle-dwelling, infaunal and colonizing invertebrates were collected from 13 stations representing a wide range of types and degrees of pollution using Surber, scoop and artificial substrate samplers. The data were summarized using the indices S (number of taxa), N (number of individuals), H (Shannon-Wiener's diversity index), D (Simpson's diversity index), BBI (Belgian Biotic Index), TBI (a modification of Hilsenhoff's Biotic Index), % CHIR (percentage of arthropods consisting of Chironomidae) and %OLIGO (percentage of total organisms consisting of Oligochaeta). Different components of the community generated somewhat different assessments and were, therefore, complementary. Community composition, expressed as the percentage of individuals contributed by major taxonomic groups, reflected the kinds of stresses at a station more consistently than did any of the indices. S and TBI came closest to ranking control, agricultural and municipal/industrial sites in accordance with our a priori classification, both between months and among sampling methods. %OLIGO usually separated municipal/industrial sites from control sites. Other indices were found to be less sensitive, accurate or temporally stable, or were otherwise inappropriate for use with certain sampling methods or for certain types of pollution. With most of our samples, all of the summary indices suggested that the impact of agricultural practices on stream ecosystems may be as severe as the impacts of municipal and industrial wastes.  相似文献   

20.
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