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1.
P. Succop S. Clark C.-Y. Tseng R. Bornschein M. Chen 《Environmental geochemistry and health》2001,23(1):1-15
A unique data set from lead risk assessments performed on 67 public housing developments from across the United States was made available for analyzes. The data set includes results of lead analysis from 5906 dust wipes and from 1222 soil samples. A total of 487 dwelling units in these developments, as well as associated common areas, were sampled, all by the same team of inspectors. The number of dwelling units within a development that were sampled reflected the guidelines then in force, the 1990 Interim HUD Guidelines, rather than those specified in the 1995 Guidelines. Median dust lead loadings for floors, 151gm–2 (14gft–2), and window sills, 936gm–2 (87gft–2), were much less than former HUD limits of 1076gm–2 (100gft–2) and 5380gm–2 (500gft–2), respectively and are only about one-third of the recently established limits of 431gm–2 (40gft–2) and 2690gm–2 (250gft–2). In contrast, the median lead loading for window troughs, 8560gm–2 (795gft–2), was almost identical to the HUD clearance limit of 8610gm–2 (800gft–2). There was a strong positive correlation between floor and window trough lead loading values for samples from the same dwelling units and those from common areas of the housing developments. Door threshold samples, which may reflect conditions exterior to the dwelling unit, were collected from 53 dwelling units. Median lead loading levels of these samples were more than ten times higher than those in floor samples from the same dwelling units, were about the same as window sill samples and about one-half of levels in window trough samples. Composite sample results, simulated by averaging results from four samples within a dwelling unit, revealed that in order to have the same rate of excedence of standards, the composite standards would have to be reduced, for example, from the single sample value of 1076gm–2 (100gft–2) to 527gm–2 (49gft–2) for floor samples and from the single sample value of 8610gm–2 (800gft–2) to 5160gm–2 (479gft–2) for window troughs. For this public housing data set, the portion of the units in developments containing more than 225 units which exceeded the established limit for window samples was the same when using either the full data set or a random one-half of the data set. This suggests that, for this data set, the number of dwelling units sampled was excessive . Thus, the required increase in the number of dwelling units to be sampled specified in the 1995 Guidelines for developments with more than 225 dwelling units, may not have been necessary if this data set is representative of public housing developments in the United States. 相似文献
2.
Soil and water samples were collected from the Susaki area of Korinthos and analysed for heavy metals in order to evaluate their environmental impact. The geology of the studied area includes ultrabasic rocks and Neogene and Quaternary deposits whereas magnesite veins are found within the ultrabasic rocks. In the north part of the studied area post volcanic emissions of H2S, CO2 and H2O vapor continue to the present day. All the samples were analysed for heavy metals by the ICP method. The element ranges (in g g–1) for soil samples are: Cu 11–63, Pb 5–256, Zn 21–604, Ni 183–2665, Co 12–124, Mn 456–1434, As 5–104, Sr 44–730, V 21–84, Cr 163–2346, Ba 48–218, Zr 3–41, Y 3–13. The metals Pb, Zn, Ni, Co, Cr, Fe, Cu, Mn, As and Sr are enriched in the Susaki soils. The element ranges for water samples are: Cu 65–103ppb, Pb<10ppb, Zn<5ppb, Ni 21–163ppb, Co 2–12ppb, As<30ppb, Cr<20ppb, Ba 36–785ppb, Sb<10ppb, W<10ppb, Bi<30ppb, Mn 0.0–0.9 g g–1, Fe 0.01–0.22 g g–1, Na 843–3076 g g–1, K 98–278 g g–1, Si 39–65 g g–1, P 0.1–0.2 g g–1. There is a natural pollution of soils with elevated concentrations of Ni, Co, Mn, Fe and Cr due to the presence of ultrabasic rocks. Another natural case of As pollution of soils is due to the volcanic activity and the geothermal field in the area. The geochemical data of ground waters and also the 18, D data showed a mixing in different proportions between sea water and meteoric water. 相似文献
3.
Environmental Accumulation of Airborne Fluorides in Romania 总被引:2,自引:0,他引:2
The nature and extent of pollution from an aluminium smelter and a fertiliser factory in Romania were studied. These are large industrial complexes, and both types of industry are known to release fluorides into the atmosphere. In grass samples collected from around the aluminium smelter, the maximum fluoride levels were found to be 4023mgkg–1 and 162mgkg–1 in unwashed and washed grass samples respectively, and 89mgkg–1 in soils. For the fertiliser factory, the maximum levels in washed grasses were found to be 207mgkg–1, and 11mgkg–1 in the soils. In both locations, these maximum values were obtained in samples collected from within 200m of the factory limits, and compare with regional background levels of less than 10mgkg–1 for grasses and 2mgkg–1 for soils. The high fluoride levels of fluoride in the grasses are sufficient to give cause for concern for the effects that these could have on the local population and on grazing animals. 相似文献
4.
Three study areas of Kwanak campus (Seoul National University), Boeun (Choongbuk) and Gapyung (Kyonggi) were selected and classified according to their bedrock types in order to investigate soil–gas radon concentrations. The mean values of radon concentrations decreased in the order of Gapyung (40BqL–1) > Kwanak campus (30BqL–1) > Boeun (22BqL–1), and decreased in the order of granite gneiss > banded gneiss > granite > black slate–shale > mica schist > shale–limestone > phyllite schist according to bed rock types. Variation in radon emanation with water content in soils and with soil grain size was assessed by the modified Morse (1976) 3min method. Soil–gas radon concentrations increased with increasing water content in the range of less than about 6–16wt.%, but decreased above 6–16wt.%. Radon concentrations also increased with decreasing soil grain size. Radioactivity analysis of radionuclides of 238U series in some soil samples indicated their possible radioactive disequilibrium between 226Ra and 238U due to the differing geochemical behaviour of intermediate radionuclides. Thus, a radioactive isotope geochemical approach should be necessary for soil–gas radon study. 相似文献
5.
Levels of Pb, Zn, Cu, Cr, Ni and Cd were determined in topsoil and vegetation in the vicinity of a factory manufacturing lead- batteries in Ibadan, Nigeria. The samples were collected along five transects in different directions, and varying distances up to 1000m from the factory. Soil lead levels were found to be elevated around the factory, with average levels of about 2000mgkg–1 close to the fence that declined gradually to about 50mgkg–1 some 750m away. Soil-lead level around a primary school located about 500m from the factory was as high as 1450mgkg–1. Lead levels were equally elevated in the vegetation, though average levels in vegetation were slightly lower than in the soil. Cadmium concentrations in soil and vegetation, though low, were more positively correlated with lead levels than any of the other metals are with lead. 相似文献
6.
A Geochemical Survey of Topsoil in the City of Oslo, Norway 总被引:9,自引:0,他引:9
The city of Oslo is situated centrally in the Oslo-graben, which is a Permian rift basin consisting of different kinds of volcanic and sedimentary rocks. In the summer of 1998, approximately 300 samples of surface soil (2–3cm) were taken systematically, 1km–2. The investigated area covers about 500km2. Samples were dissolved in 7M HNO3 and analysed for 29 elements with ICP-AES, mercury with cold-vapour technique (CV-AAS) and arsenic and cadmium with a graphite furnace (GF-AAS). A factor analysis is frequently used to identify relationships among sets of interrelated variables. To describe the covariant relationships among the elements, a factor analysis has been completed. The first factor contains the elements Sc, Fe, Li, Co, Al, Cr, Be, K, Ni, V, Mg, Y, Ba, Zr, Mn and As (listed with decreasing communality). These elements are typical for the minerals in the area and most of these elements have a near normal distribution. Sources for this factor are probably geological. The second factor contains Cd, Hg, P, Zn, Cu, Ba and Pb. They have a log-normal distribution. Road traffic is probably one of the sources contributing to this factor. In Norway studded tyres are used frequently in the winter season which results in large amounts of road dust. Leaded petrol has been a major source for Pb but is not in use any more. Wear and tear of tyres and brakes contribute also to this factor. Other sources contributing to this factor are probably industry, rubbish incineration, crematoria and release of some of these elements from structural material by fire. Factors 3, 4 and 6 with elements such as Ca, Na, La, Ti and Sr probably have geological sources. They are associated with minerals like amphiboles, pyroxenes and feldspars and some of the elements are from sea aerosols. Factor 5 contains Mn, Cd, Zn, As and Pb. Manganese may be derived from many different sources such as rock weathering, windblown dust, agriculture and traffic. Since As and Mn are placed in both factor 1 and 5 they probably have both geological and anthropogenic sources. Concentrations of the elements in the second factor are much higher in the central parts of Oslo, than in the rest of Oslo. The median value of Hg in the centre is 0.48mgkg–1, which is 8 times higher than that in the rest of the city. Also, the other elements have much higher levels in the centre. The industrial district north-east of the centre also has high values. The distribution of arsenic is regular throughout the whole city, but has a slightly higher level in the centre. Norm values for contaminated land used by the Norwegian authorities are 2mg As kg–1 and 25mg Cr kg–1. Of 297 samples, 61% contain more than 25mg Cr kg–1 and 79% more than 3mg As kg–1, which is the detection limit of the analysis. These samples will therefore be regarded as contaminated. Factor analysis places these elements in the geological factor. The Norm value of zinc is 150mgkg–1, and 40% of the samples contain more than this. The Norm value of lead is 150mgkg–1, and 35% of the samples contain. Road traffic is probably the major source for these elements. 相似文献
7.
Distribution of selected elements and PAH in freshly deposited sediments of waste water streams from Lubin district, Southwest Poland 总被引:1,自引:0,他引:1
Yu‐Zhuang Sun 《Environmental geochemistry and health》1999,21(2):141-155
Nine selected elements (Cu, Pb, As, Zn, Co, Ni, Cr, Cd and Fe) were determined by inductively coupled plasma atomic emission spectroscopy in 15 samples from the tailings pond (Zelazny Most) and waste water streams (Moskorzynke and Rudna) in the Kupferschiefer mining district in Southwest Poland. Waste water from mining and industry enter the Zelazny Most pond. The water then flows through Moskorzynke and Rudna streams, and discharges into the River Odra. The analytic results indicate that the contamination with Cu, Pb, Zn, As, Co, Cd and Fe extend about 6km along the streams in contrast to the nonpolluted samples close the River Odra. Their concentrations reach a level, which could be toxic for plants, animals and humans. The contamination with Ni and Cr continued at least 20km along Rudna stream. Besides mechanical transport, redox conditions and Corg contents also played an important role for trace element and Fe contamination in Rudna stream. The samples with high Corg contents have also high contents of trace metals. In Moskorzynke stream the element contamination was mainly caused by mechanical transport of particles. Polyaromatic hydrocarbon (PAH), which is abundant in Kupferschiefer, is toxic for animals and humans. The PAH concentration in the stream sediments was determined by GC and GC/MS. The results indicate that the contamination of PAH reaches 6 and 17mgkg–1 in samples TP1 and RS6, respectively. In the other samples, the PAH contents are lower than 3mgkg–1. Some PAH could be solved by waste water in the tailings pond and migrated to the stream sediments. Some PAH might be contained in particles which were transported mechanically from the tailings pond into stream sediments. 相似文献
8.
John J. McAlister Bernard J. Smith Jose A. Baptista Neto 《Environmental geochemistry and health》2000,22(3):195-210
Established research in first world urban environments has shown street sediments to be effective sinks for heavy metals and emphasises the health risks to children by its inhalation or ingestion. In third world countries with fewer pollution controls, contamination may be augmented by additional pollutants such as sewage discharge into urban streets and/or periodic inundation with sewage-laden run-off. This pollutant not only contains heavy metals and organic matter, but calcium oxalates that may derive directly from the sewage itself. To study this premise street sediments were collected from sites of varying industrialisation and sewage contamination within the city of Niteroi, Brazil. Calcium oxalate dihydrate (weddellite) was identified by X-ray diffraction, fourier transform infra red and scanning electron microscopy techniques and oxalate concentrations in <63m and colloidal (clay and organic matter) fractions, were determined by ion chromatography. Oxalate in colloidal fractions averaged 43601mgkg–1 in sewage contaminated industrialised urban zones, 4519mgkg–1 in suburban areas and 17477mgkg–1 in suburbs with favelas (shantytowns-of Niterói). Oxalate concentrations coincide with high levels of metal ions (Fe, Mn, Zn, Pb, Ni, Cr) that stabilise calcium oxalate dihydrate and prevent its dehydration to the monohydrate (whewellite). Lower levels of oxalate were found in lichen-covered roof sediment, plaster and mortar samples. Oxalate concentration coincides with sewage contamination and street sediments appear to act as a sink for calcium oxalate dihydrate derived from sewage. Previous studies have shown that low levels of exposure can damage kidneys and the nervous system, while prolonged exposure can cause severe corneal, retinal and skin damage, cyanosis and possibly gangrene. Contact with blood serum may result in hypocalcemia, muscular stimulation, convulsions and finally collapse. The conditions described are common throughout urban areas of the developing world and may suggest a particular environmental hazard in these regions. 相似文献
9.
An investigation on the abundance and distribution of trace metals (Fe, Cu, Zn, Mn, Cr, Cd and Pb) in water, and nine species of fish samples from Calabar river was carried out in 1992. The concentrations of iron (6000–7240gl–1), zinc (4910–7230gl–1), and cadmium (3–7gl–1) showed moderate pollution while those of copper (420–630gl–1), manganese (23–48gl–1), chromium (<10–20gl–1) and lead (<1–10gl–1) in water were well below WHO permissible levels. Significant seasonal changes (0.001p0.25) were obtained for iron, copper, zinc, manganese and cadmium in water. Furthermore, iron, zinc and cadmium showed statistically significant spatial changes (0.005p0.10). Of the nine fish species studied, no statistically significant relationship between body weight and the concentrations of the metals was observed. The concentrations of the metals per mean total body weight apparently decreases in the order Fe>Zn>Cu>Mn>Pb>Cd=Cr and were within the limits that were safe for consumption. 相似文献
10.
B. E. Davies Claudio Bifano K. M. Phillips J. L. Mogollon M. Torres 《Environmental geochemistry and health》1999,21(3):227-256
Surface soils (0–15 cm) were sampled at 10–20 km intervals along two transects in Venezuela. One (1162 km, 70 samples) ran west to east parallel with the Caribbean coastline, the other (920 km, 92 samples) ran south to north from the frontier with Brazil to the Caribbean shore. Sampling took place in both a wet and a dry season. Trace metals were extracted from dried, sieved (<2 mm) soil with boiling aqua regia followed by analysis by ICP or flame AAS. Metal values did not differ significantly between the two seasons and dates were averaged. Geometric mean values for the west–east transect were: Cr=41.5, Cu 17.9, Cs 3.6, Li=13.9, Mn=294, Ni=21.3, Pb=17.4, Sr=39.4, V=60.4 and Zn = 83.7g g–1, respectively. Similarly, for the south–north transect Cr=21.3, Cu=4.3, Cs=1.1, Li=2.0, Mn=55.7, Ni=4.4, Pb=6.1, Sr=13.3, V=28.2 and Zn=16.7g g–1, respectively. A classification of samples by lithology showed surface soil composition to be related to rock composition. Metal values were low in the soils in the south of the country, in the Guyana highlands (Gran Sabana). Low Zn contents were prevalent. Lead contents were affected by roadside fallout from vehicles using leaded petrol except that high Pb contents of soils in the Gran Sabana were of more complex origin. 相似文献
11.
Margaret E. Farago Iain Thornton Nicola D. White Inge Tell Maj‐Britt Mårtensson 《Environmental geochemistry and health》1999,21(1):67-82
Scandinavia has one secondary lead smelter that recycles lead from approximately 85% of used car batteries in Scandinavia and which has been active since the 1940s. The smelter, situated in Landskrona, has undergone a comprehensive clean up programme during the last decade, during which time production has doubled, while at the same time discharges of dust and lead to the atmosphere have decreased.Top and depth soil samples were taken on a 0.5km×0.5Km grid throughout the city of Landskrona, which covers an area of approximately 15km2. Samples were analysed by ICPAES for a number of elements including Pb, Zn, Cu, Cd, As, Sb and Hg. Road dust samples from selected sites were collected and similarly analysed. Blood samples were taken from 37 volunteer schoolchildren (aged 8–11) from two schools in Landskrona. House dust samples were taken from each child's home. Soil samples were taken from homes which had gardens, public and school play areas. Elevated heavy metal concentrations were found in close proximity to the secondary lead smelter, and this soil enrichment influences the whole of the town, modified to some extent by the prevailing wind. The smelter does not influence the soil lead concentration at distances greater than 3.5km, where the soil reflects the background value for the area.Road dust samples also show decreases in lead concentrations with distance from the smelter. The average level of lead in house dust was considerably lower than that found in Birmingham, UK. Blood lead levels in the child population ranged from 1.5–5.1gdl–1, with a mean of 3.05gdl–1, showing a distinct decrease from those measured in 1978–82. No significant difference in blood lead concentrations with distance of the home from the smelter, nor between attenders at the two schools was revealed in the limited number of children studied. 相似文献
12.
Chi-Wen Lin 《Environmental geochemistry and health》2002,24(1):23-33
For the past two decades, the Taiwan Environmental Protection Administration has made a systematic investigation of As, Cd, Cr, Cu, Pb, Hg, Ni and Zn in agricultural soils to identify soil pollution from industrial production. The EPA has cooperated with local governmental agencies to establish a soil quality monitoring system that would upgrade the land recovery ability and prohibit polluted lands from being cultivated or turned over to other uses. Based on an island-wide soil survey, more than 1,000 hectares of arable soils in Taiwan were found to be considerably contaminated by heavy metals. One of the heavy metal contaminated sites, located near a ceramic product manufacturing factory in Nantou County, was identified as lead contaminated. According to the Nantou Environmental Protection Bureau, the lead content in contaminated sites showed a great variation of several mg Pbkg–1 soil to several thousands mg Pbkg–1 soil. Therefore, it is appropriate to estimate the lead spatial distribution through geostatistics such as Kriging. The soil lead concentration contour maps obtained by Kriging can help us to identify the pollution patterns and delineate the range of contaminated sites. The purpose of this study is to determine the Pb concentrations at each location by performing detailed soil sampling on those Pb contaminated sites and estimating the lead spatial distributions by Kriging. A total of 70 soils were sampled from different locations at two experiment sites. Lead contents were determined with 0.1M HCl extractable lead content of the soils. The results obtained by investigating the lead contents in each 15cm segment down to a 60cm depth, revealed that lead contents were greater in arable land near the ceramic products manufacturing factory, and lead concentrations decreased with depth. In addition, Pb concentrations in heavily contaminated soils showed heavy concentrations of Pb in specific locations. Results from Pb content spatial distributions indicated that the Kriging model is a useful tool and can provide decision-makers with critical information for delineating hazardous areas in heavy metal contaminated sites. 相似文献
13.
This study investigated geochemical characteristics of the acid mine drainage (AMD) discharged from the abandoned mine adits in the vicinity of the Dogye coal mine in Korea. Acid mine drainage discharged from Jeoncha pit adit of the Dogye coal mine, which is the main source of the AMD in the study area, had a pH value of 3.0 and concentrations of 2148mg SO4
2– L–1, 229mg Fe L–1, 71mg A1 L–1 and 11mg Mn L–1. The reduction of some metal concentrations downstream from the discharge point could be explained on the basis of dilution and precipitation. The order of removal of metal ions downstream from the discharge point was Fe>A1, Cu>Zn, Mn. Acidity could be used as a good determining factor offering comprehensive and quantitative values for the polluting extent of acid mine drainage. The acidities existing in all acidic water samples in the Gunahan district originated primarily from mineral acidity, especially in the upper Nahan Creek from dissolved Fe and Al and in the middle and down Nahan Creek from dissolved Al. From the application of the WATEQ4F program, it was determined that predominant species of dissolved Fe in all water samples was Fe2+, and those of dissolved Al were AlSO4
+ and Al3+ except for IW2 sample which was associated with white precipitates. The species of dissolved Al in IW2 sample include also AlOH2+ and Al(OH)2
+. The saturation indices of goethite and haematite were positive in the water samples associated with ochrous precipitates (usually called Yellow Boy), therefore these solids might be precipitated. For the IW2 sample, the saturation indices of amorphous Al(OH)3 and gibbsite were positive, so theoretically these solids might also be precipitated. By XRD analysis, it was found that goethite occurs in ochrous precipitates, and gibbsite in white precipitates. 相似文献
14.
Mari S. Golub Carl L. Keen Joel F. Commisso Charles B. Salocks T.R. Hathaway 《Environmental geochemistry and health》1999,21(3):199-209
A potentially high bioavailability of arsenic in gold mine tailings from a site in northern California has been suggested by solubility studies. To help address this issue, an in vivo dosing study was conducted using 12dayold Swiss Webster mouse pups (n=8/group). A sample of sizefractionated mine tailings from the site (<20m particle size, 691g g–1 arsenic) was prepared as an aqueous suspension and administered by gavage in a volume that provided 4mg As/kg body weight. The control group received the same volume of a commercial soil (1g g–1 As) of similar particle size (<60m). No mortality or toxic signs were noted in either group. Tissue samples were collected 1h after gavage, freezedried, microwavedigested and analysed for arsenic by ICP/MS (detection limit 2ng As g–1 dry weight). Arsenic concentrations (ng As g–1 dry weight) in tissues from the pups who received mine tailings were significantly higher than in control tissues. The mean elevation in arsenic concentration was highest in the liver (3364% of control, p<0.0001), followed by blood (818 of control, p<0.0001), skin (207% of control, p=0.07), and brain (143% of control, p<0.0001). The carcass arsenic concentration (excluding the GI tract, liver, brain and skin) was 138 of control (p=0.02). The data indicate uptake of arsenic from weathered mine tailings by the immature mouse pups after oral exposure. 相似文献
15.
Diesel oil is a complex mixture of hydrocarbons with an average carbon number of C8–C26. The majority of components consist of alkanes, both straight chained and branched and aromatic compounds including mono-, di- and polyaromatic hydrocarbons. Regardless of this complexity, diesel oil can be readily degraded by a number of soil microorganisms making it a likely candidate for bioremediation. The concept of using plants to enhance bioremediation, termed phytoremediation, is a relatively new area of scientific interest. It is particularly applicable to diesel oil contamination as diesel oil generally contaminates the top few metres of soil (surface soil) and contamination is not uniform throughout the site. By encouraging plants to grow on diesel oil contaminated soil, conditions are improved for the microbial degradation of the contaminant. During this study, establishing plants on diesel oil contaminated soil proved difficult. Diesel oil is phytotoxic to plants at relatively low concentrations. At concentrations below this phytotoxic level, the development of plants grown in diesel oil contaminated soil differs greatly from plants grown in uncontaminated soil. Tolerance of plants to diesel oil and ability to germinate in diesel oil contaminated soil varied greatly between plant species as well as within plant species. The broadest differences in germination were seen within the grasses with certain species thriving in low levels of contamination (e.g. Creeping bent) while others were intolerant of diesel oil contamination (e.g. Rough meadow grass). The herbs, legumes and commercial crops screened appeared to be largely unaffected by low levels of diesel oil contamination (25g dieselkg–1). At the higher level of contamination (50g dieselkg–1), half of the twenty two plants species screened failed to reach a germination rate equal to 50% of the control rate. Two species of grass failed to germinate at all at this contamination level. Plant species that successfully germinated and grew were studied further to determine the effect of diesel oil contamination on the later stages of plant development. This work investigates the effect of diesel oil on plant growth and development. 相似文献
16.
Felicia J. Higgs Howard W. Mielke Michelle Brisco 《Environmental geochemistry and health》1999,21(1):27-36
Soil studies, conducted in Maryland, Minnesota and Louisiana, have described the urban pattern of lead contamination. They have shown that the highest amounts of lead cluster within the interior of the largest cities. The results of the New Orleans urban patterns of distribution of soil lead provided the basis for further study. The hypothesis was tested that elementary school properties have the same pattern of soil lead contamination as their neighbouring residential communities. Thirty New Orleans Public Elementary Schools were selected for this study. Surface samples (2.5cm or 1 inch depth) were collected from playgrounds and next to entrances of each school. Results showed that soil lead on school properties follows the same relative contamination patterns (pvalue10–5) as soil lead on residential properties of neighbouring communities. Schools however, have significantly lower lead contamination than the neighbouring residential properties. Innercity school properties present a higher risk of soil lead exposure than mid and outercity schools. Soils next to innercity school entrances showed the highest lead, with 18.5% having concentrations over 400gg–1. Systematic landscaping around the school entrances would significantly reduce the hazard from lead dust contaminated soils. 相似文献
17.
The distribution of heavy metals in deposited urban dusts and sediments, Coventry, England 总被引:11,自引:0,他引:11
Samples of urban dusts and sediments have been collected and categorised into three compartment those which act mainly as sources, those undergoing transport and those which have been deposited. The sediments were fractionated into <63m to match similar sized lacustrine sediments and <2mm to represent natural and anthropogenic fluvially transported sediments. Preliminary results of total heavy metals analysis show that the <2mm fraction of the source group exhibits the greatest variabilty in metal concentrations. Overall, however, the <63m fraction dominates regardless of compartment. Some heavy metal concentrations decrease through the sourcetransportdeposit process, possibly due to selective onward transport of finer material or other anthropogenic processes unique to the urban environment (e.g. street cleansing). Sitespecificity is indicated in a comparison with other similar studies. 相似文献
18.
Jennifer M. Hazen Mark W. Williams Bruce Stover Mike Wireman 《Environmental geochemistry and health》2002,24(1):1-22
The legacy of mining continues to affect stream water quality throughout the western United States. Traditional remediation, involving treatment of acid mine drainage from portals, is not feasible for the thousands of abandoned mines in the West as it is difficult and expensive. Thus, the development of new methods to address acid mine drainage is critical. The purpose of this study was two fold; to identify and test new tools to identify sources of metal pollution within a mine and to identify low-cost treatment alternatives through the use of these tools. Research was conducted at the Mary Murphy Mine in Colorado, a multiple-level underground mine which produced gold, silver, copper, lead and zinc from 1870 to 1951. Source waters and flowpaths within the mine were characterised using analysis of hydrogen and oxygen isotopes of water (water isotopes) in combination with solute analysis and hydrometric techniques. Hydrometric measurements showed that while discharge from a central level portal increased by a factor of 10 during snowmelt runoff (from 0.7 to 7.2 Ls–1), Zn concentrations increased by a factor of 9 (from 3,100 to 28320gL–1). Water isotopes were used as conservative tracers to represent of baseflow and snowmelt inputs in a hydrologic mixing model analysis. The results showed that less than 7% of peak discharge was from snowmelt. Within the mine, approximately 71% of the high-flow Zn loading was caused by a single internal stream characterised by extremely high Zn concentrations (270600gL–1) and low pH (3.4). Somewhat surprisingly, hydrologic mixing models using water isotopes showed that new water contributed up to 79% of flow in this high-Zn source during the melt season. Diversion of this high-Zn source within the mine resulted in a decrease in Zn concentrations at the portal by 91% to 2,510gL–1, which is lower than the base-flow Zn concentration. The results suggest that in some mines remediation efforts can be concentrated on specific areas within the mine itself. Using the characterisation techniques demonstrated in this study, problem areas can be identified and contaminated flows diverted or isolated. The results also suggest that it may be possible to dewater contamination areas, greatly reducing costs of remediation. 相似文献
19.
T. Strömgren 《Marine Biology》1982,72(1):69-72
The shortterm (10–22 d) effect of Zn, Hg, Cu, Cd, Pb, and Ni on the length growth of Mytilus edulis is studied. Significant reductions of growth rate was found at 0.3 g Hgl-1, 3 g Cul-1, 10 g Znl-1, and 10 g Cdl-1 added to the local sea water, while concentrations of up to 200 gl-1 of Pb and Ni had no effect on the growth. With exposure to Cu and Zn, there was a linear reduction in growth rate with increasing metal concentration up to about 6 g Cul-1 and 100 g Znl-1. Above these levels, growth stopped with Cu, while with Zn it was stabilized at about 20% of control growth. When Hg and Cd were added, a curvilinear relationship between growth and metal concentration is indicated. With Hg, growth rate is nearly zero above 3–4 g Hgl-1, while the growth rate was 50% of control after 10 d of exposure to 100 g Cdl-1. At 2 g Cdl-1 there was a significant stimulation of length increase. Observed EC50-values for growth were 0.3–0.4 g Hgl-1, 3–4 g Cul-1, 60 g Znl-1, and 100 g Cdl-1. 相似文献
20.
Years of political instability have left Lebanon with significant gaps in environmental knowledge. This paper reports new results for trace metals in bed sediments of the river Nahr-lbrahim. The drainage basin of the river Nahr-lbrahim is largely floored by karstified limestone. Metal pollution is operative within the catchment. The objectives of this study were first to identify possible sources of metals (geological and/or anthropogenic) and then to characterise the chemical partitioning of the metals in the sediments. Bed load sediments were sampled at five locations along a 13km stretch from the river mouth, during the dry season. Samples were collected on two dates, dried and then sieved into three mechanical fractions. We report total Fe, Cu, Pb and Zn contents of the <75m sediment fraction for the dry season and interpret the results in terms of geology and point and non-point discharges to the river. Total metal contents were derived from summing the concentrations of metals in the chemical fractions of the sediments. A sequential chemical extraction procedure was applied to the <75m fraction and the data showed that, except for Fe, the carbonate fraction had the largest role in metal sediment deposition. 相似文献