Metals In Lake Sediments Research Articles

The Spatial Distribution of Characterised Fly-Ash Particles and Trace Metals in Lake Sediments and Catchment Mosses in the United Kingdom

Spheroidal carbonaceous particles (SCP) and trace metals (Cd, Cu, Pb, Ni, V and Zn) were analysed from 75 lake surface sediments across the UK. Trace metals were additionally analysed from catchment mosses (Hylocomium splendens and Pleurozium schreberi) from 43 of the sites but were absent from the remainder. Spatial distribution of SCP concentration and trace metal concentrations in sediments and mosses showed good agreement with each other and with known emission sources. Particles were allocated to their fuel-type and spatial trends in these data showed good agreement with potential sources. High areas of oil particle deposition were identified in the south-east of England, Merseyside, Galloway / Northern Ireland, the Firth of Forth and eastern Scotland. Oil SCP concentrations showed good agreement with Ni and V concentrations in mosses suggesting an atmospheric source for these metals from the combustion of this fuel. Characterised SCP trends also showed good agreement with predictions from models such as HARM and EMEP. Most high deposition areas of metals and particles were found to coincide with population centres suggesting a possible impact on human health.

The Spatial Distribution of Characterized Fly-Ash Particles and Trace Metals in Lake Sediments and Catchment Mosses: Czech Republic

As a part of the FLAME research project funded by the EU COPERNICUS programme (1994-1996) samples of surface sediments were taken from 31 man-made lakes and one natural lake in the Czech Republic. The sites differ considerably in their altitude, area, catchment, depth, retention time, trophic status, and in parameters of local air pollution. The samples were analysed for concentration of spheroidal carbonaceous particles (SCP, numbers per gram dry mass of sediment), a characteristic component of industrial fly-ash. The extracted carbonaceous particles were allocated according to the fuel-types combusted throughout Europe (coal, oil, brown coal, peat, oil shale) using particle chemistries derived by energy dispersive spectroscopy (EDS). Trace metals were also analysed in the surface sediments as were mosses sampled at the study sites. The main objectives of the study were (i) to look for factors determining SCP concentrations in surface sediments of lakes, with special emphasis on the distribution of large fossil-fuel combustion sources (ii) to compare fuel-type allocation of carbonaceous particles with combustion of these fuels within the country, (iii) to look for trends in spatial distribution of trace metals and (iv) to characterize the impact of airborne particles from these sources on environmental and human health. The SCP concentrations show little or no relation to air-pollution parameters on a small scale, although some large-scale effects are evident. A good relationship was, however, found to site characteristics such as altitude and lake area : catchment area. The reason, why this relationship is more apparent from our dataset than from any other study published so far, is likely to be based on the high variation in the physical parameters (altitude, lake and catchment area) of the sites under study. The distribution of particles attributed to brown coal combustion are in good agreement with the distribution of major air pollution sources across the country but the fraction of particles attributed to coal seems to be overestimated by the present technique. The distribution of trace metals in surface sediments are also in agreement with expected sources. The usefulness of SCP concentrations as indicators of stress to human and environmental health is briefly discussed.

The Spatial Distribution of Characterised Fly-Ash Particles and Trace Metals in Lake Sediments and Catchment Mosses: Estonia

The concentrations of fly-ash particles were studied in the surface sediments of 42 lakes in Estonia. Concentrations of both spheroidal carbonaceous particles (SCPs) and inorganic ash spheres (IASs) were determined and the particles chemically characterised to different fuel types. This was accompanied by trace metal analyses from lake surface sediments and catchment mosses in order to determine the distribution of atmospheric pollutants. The obtained spatial distribution data for fly-ash particles varied to a great extent, partly due to differences in sedimentation rates but mainly due to higher deposition in industrial areas. The distribution patterns of the different particle types in lake sediments, as well as the trace metals in mosses, show that the deposition of airborne particulates is of local origin around pollution sources and that the share of long-range transported atmospheric impurities is high along the main cyclonic routes in Estonia.

200-Year Record of Metals in Lake Sediments and Natural Background Concentrations

Lake sediments conserve important information about past conditions of a lake and its environments. We present analyses of calcium, manganese, iron, copper, zinc, cadmium, mercury, and lead in dated (210Pb, 137Cs, varve-chronology) sediment cores from Zurichsee (Lake Zurich), Switzerland, covering a time span of the last 200 years and an additional time interval between 13 500 and 15 000 years before the present time. The concentrations of these elements varied very little in pre-anthropogenic sediments and represent geochemical background concentrations. With the beginning of industrialization in the early 19th century and the corresponding growth of population, significant changes occurred in the concentrations of the investigated metals. Copper, zinc, and cadmium increased until about 1960 and decreased sharply afterwards. The increase correlates to the growth of local industrial productivity (and population growth), whereas the decrease after about 1960 was caused by (i) the introduction of sewage tre...

Metals in sediments of lakes in Latvia

The concentrations and speciation forms of Pb, Cu, Ni, Cd, Zn, and Mn have been determined in sediments from 49 lakes thoroughout Latvia to study the impact of different pollutant sources and to estimate the background pollution level. Regional variation in pollutant distributions of Pb, Cu, and Cd concentrations is due to anthropogenic load. The enrichment of metals in the top layer of sediments is an estimate of the environmental pollution level. In regions with no known pollution sources, this enrichment was not typical. Another factor that determines metal concentrations in sediments is the organic matter production and sedimentation in eutrophic water bodies.

Regional accumulation pattern of heavy metals in lake sediments and forest soils in Sweden

Concentrations of heavy metals (Pb, Cd, Hg, Zn, Cu) in the mor layer of forest soils and in recent lake sediments from small forest lakes show similar large-scale distributions in Sweden. Comparatively high concentrations of Pb, Hg and Cd are found in southern Sweden, with gradually decreasing concentrations towards the north, indicating a marked impact of long-range transport. In general, for most metals, higher concentrations are found in lake sediments than in the mor layer and also a more marked concentration gradient over the country. This is probably due in part to natural processes but also to an increased leaage in souther SSweden of especially Zn and Cd from acidified forest soils. In southern Sweden, concentrations in the mor layer have probably increased by factors of ∼ 5–10 for Pb and 3–5 for Hg and Cd, compared with estimated pre-industrial values. In sediments, the levels have increased even more. In the northernmost part of the country also, the contents of these metals are enhanced, probably by approximately a factor of 2. Concentrations of Zn and Cu do not appear to have generally increased in the mor layer. Relative increases in mor of Pb and Hg in southern Sweden are above the levels where adverse effects on soil biological processes might occur.

Heavy metals in lake sediments of the Kola Peninsula, Russia

Investigations of heavy metal content in lake sediments in the Kola Peninsula, Russia, were carried out from 1989 to 1992. The study lakes were situated at varying distances from two heavy metal pollution sources — smelters of the Pechenganickel and Severonickel Companies. Four aspects were considered: (1) values of background concentrations of heavy metals in the sediments; (2) historical trends in heavy metal concentrations; (3) regional distribution of the concentrations in surficial sediments; (4) degree of contamination and Håkanson's risk index values. Atmospheric emissions from smelters of the Murmansk region were the main sources for the increased concentrations of Ni, Cu, Co, Cd and Hg observed in young sediments within a distance of 30 km, presenting a considerable ecological risk to aquatic ecosystems. Surface sediment concentrations declined considerably away from the smelters and differences between upper and lower layers decreased. Pb concentrations increased from east to west owing to the deposition of atmospheric Pb from automobile exhaust in northern Finland and north-eastern Norway.

Heavy metals in lake sediments of the Kola Peninsula, Russia

Investigations of heavy metal content in lake sediments in the Kola Peninsula, Russia, were carried out from 1989 to 1992. The study lakes were situated at varying distances from two heavy metal pollution sources — smelters of the Pechenganickel and Severonickel Companies. Four aspects were considered: (1) values of background concentrations of heavy metals in the sediments; (2) historical trends in heavy metal concentrations; (3) regional distribution of the concentrations in surficial sediments; (4) degree of contamination and Håkanson's risk index values. Atmospheric emissions from smelters of the Murmansk region were the main sources for the increased concentrations of Ni, Cu, Co, Cd and Hg observed in young sediments within a distance of 30 km, presenting a considerable ecological risk to aquatic ecosystems. Surface sediment concentrations declined considerably away from the smelters and differences between upper and lower layers decreased. Pb concentrations increased from east to west owing to the deposition of atmospheric Pb from automobile exhaust in northern Finland and north-eastern Norway.

Focusing Patterns of Transition Metals in Lake Sediments — Indicators for the Reconstruction of Deep-Water Mixing in the Past?

Transition metals in lake sediments show characteristic focusing patterns according to their mobility, which is strongly influenced by the redox conditions in the deep water. Oxygen concentrations in deep lakes depend on two factors: The mineralization of organic matter and deep-water mixing. Under conditions of constant nutrient input the wind-induced mixing during the cold season determines whether deep waters remain anoxic during longer periods of time or if the oxygen reservoir is replenished during winter. Different transition metals such as V, Cr, Mn, Fe, Co, Mo show a broad range of behaviour with respect to adsorption, complexation and solubility depending on the redox conditions. Their concentration and distribution in lake sediments offers some potential as proxy indicators for deep water mixing and the frequency and magnitude of strong wind events. Varved lake sediments covering the last 100 years offer an opportunity to test and calibrate focusing patterns of transition metals with limnological and meteorological time series.

Progress in understanding the chemical stratigraphy of metals in lake sediments in relation to acidic precipitation

Progress in understanding the chemical stratigraphy of metals in lake sediments in relation to acidic precipitation

Distribution of Cr, Pb, Cd, Zn, Fe and Mn in Lake Victoria sediments, east Africa.

The presence of many metals at trace or ultra-trace levels in the human environment has received increased global attention. Sediments as a sink for pollutants are widely recognized pollution sources and diagenesis and biochemical transformations within the sediment may mobilize pollutants posing a threat to a wider biological community. The natural (background) concentrations of heavy metals in lake sediments can be estimated either by analysis of surface sediments in non-polluted regions or by analysis of core samples antedating modern pollution. The distribution pattern of heavy metals in tropical freshwater systems has been little studied. The authors found increased concentrations of lead and other trace metals in Lake Victoria. Thus this study was initiated in order to further investigate the distribution patterns of lead and other metals in Lake Victoria.

Geochemical associations and anti-ropogenic trace metals in lake sediments of Central Italy

Geochemical associations and anti-ropogenic trace metals in lake sediments of Central Italy

Concentration and annual accumulation values of heavy metals in lake sediments: Their significance in studies of the history of heavy metal pollution

Concentration and annual accumulation values of heavy metals in lake sediments: Their significance in studies of the history of heavy metal pollution

Simulated mobilization of metals from sediments in response to lake acidification

The regeneratable forms of pollutant metals in lake sediments were estimated using different chemical extractants and the effects of lake acidification on the mobilization of such metal fractions studied in laboratory microcosm. The release of each metal was found to increase exponentially below a threshold pH value, which was about 4.0 for Cu, Ni, Zn, Cd and Fe. The data suggest that a large percentage of pollutant metals are mobile as determined by chemical extraction techniques and long-term release experiments.

Geochemical Pathway Studies of Heavy Metals in Lake Sediments from the Sudbury-Temagami Area, Ontario

The concentrations of some heavy metals in lake sediments from the Sudbury-Temagami area were determined by radiochemical neutron activation, atomic absorption, and x-ray fluorescence. Data for dredge samples from 23 lakes indicate that concentration gradients for Pd, As, and Se tend to center about the Sudbury industrial complex and increase toward it. Metal concentration profiles over the top 20 cm of sediment cores from five lakes show pronounced increases in Pd, Ir, Au, As, Se, Cu, Ni, and Pb in the top 5 cm. These data suggest that one of the principal pathways for heavy metal loading of lake sediment in the area is atmospheric fallout of particulate material.

Sediment-Water Interchange of Copper and Nickel in Experimental Aquaria

Abstract Lake and stream sediments often reflect recent additions of heavy metals before elevations of such elements are detectable in the overlying water. Concentrations of metals in sediments of lakes may be three to four orders of magnitude greater than in the water. While tests of water quality may, therefore, indicate no elevated metal levels in the soluble phase, a water body may still be heavily polluted, with organic and inorganic material in sediments acting as sites for precipitation and adsorption of the metals. The possibility of reentry of sedimented material into the water, due to physical, chemical or biological processes in natural situations, always exists. Experimental work was carried out on nickel and copper in the sediments of Middle Lake (recently limed to pH 6.5, and fertilized) and of Clearwater Lake (untreated), Sudbury, Ontario, under a variety of physical and biological conditions in aquaria. Results showed that both copper and nickel increased in concentration in water overlying the sediments, eg. in “live” aerobic systems over 28 days total copper in water increased from 0.15 to 0.85 ppm, and total nickel from 0.3 to 3.0 ppm. The pH of the water, initially 6.5, dropped to below 4.0. In sterile anaerobic conditions, total copper decreased slightly, and total nickel remained constant, while pH in this condition initially dropped only slightly, and at 28 days was 6.0. The “live” anaerobic system was intermediate in all these respects. “Free” copper at lower pH values (measured by differential pulse anodic stripping voltammetry) was predictably equal to total copper (measured by flame atomic absorption or by anodic stripping), but in the sterile anaerobic treatments where pH was 6.0, “free” copper was less than 50% of the total copper. Since ionic copper is believed to be the form toxic to biota, the lowered pH and increased ionic copper in water close to the sediments appears to have serious implications.