Natural Sources Of Metals Research Articles

An insight into source apportionment of metals in superficial sediments from the Tien Hai nature reserve of the Red River delta, Vietnam.

In the present study, concentrations of 23 metallic elements (Al, Fe, K, Mg, Ti, Mn, V, Cr, Co, Ni, Cu, Zn, Ga, As, Sr, Zr, Mo, Cd, Ba, W, Hg, Pb and U) were determined in superficial sediments from 20 sites within the Tien Hai nature reserve of the Red River delta. An integrated approach including correlation analysis (CA), principal components analysis (PCA) and positive matrix factorization (PMF) was combined to identify and quantify the sources of these metals. The results indicated that the correlation analysis was able to identify both allochthonous and authigenous origin of metals while the remaining methods were unable to identify these origins. With the help of CA, the PMF model performed better at the source identification of metals than the PCA. The results of PMF demonstrated that weathering products formed on different parent rocks were the biggest contributor to natural sources of metals in the superficial sediments, while agricultural activities were regarded as the major contributor to anthropogenic sources of metals. These findings could provide a scientific basis for environmental protection authority to prevent and control the sediment metal pollution. Accordingly, application of organic amendments and reduction of inorganic fertilizer should be encouraged to minimize metal accumulation in sediments.

Volatile metal emissions from volcanic degassing and lava\u2013seawater interactions at K\u012blauea Volcano, Hawai\u2019i

Volcanoes represent one of the largest natural sources of metals to the Earth’s surface. Emissions of these metals can have important impacts on the biosphere as pollutants or nutrients. Here we use ground- and drone-based direct measurements to compare the gas and particulate chemistry of the magmatic and lava–seawater interaction (laze) plumes from the 2018 eruption of Kīlauea, Hawai’i. We find that the magmatic plume contains abundant volatile metals and metalloids whereas the laze plume is further enriched in copper and seawater components, like chlorine, with volatile metals also elevated above seawater concentrations. Speciation modelling of magmatic gas mixtures highlights the importance of the S2− ligand in highly volatile metal/metalloid degassing at the magmatic vent. In contrast, volatile metal enrichments in the laze plume can be explained by affinity for chloride complexation during late-stage degassing of distal lavas, which is potentially facilitated by the HCl gas formed as seawater boils.

Metal geochemistry in suspended and bed sediments in the eutrophic lowland Salado River basin (Buenos Aires, Argentina)

The Salado River is a lowland river that drains a vast and productive region of central Argentina into the Río de la Plata estuary. To evaluate water quality and the geochemistry of major and trace metals (Fe, Mn, Zn, Cu, Pb, Cr and Ni), water and sediments samples were collected along 500 km of the Salado River basin (n = 21). Waters were highly alkaline (pH: 8.8 ± 0.4), saline (5.2 ± 1.8 mS/cm), turbid (467 ± 237 NTU) and eutrophic (chlorophyll a: 187 ± 119 µg/l) with a decreasing gradient towards the river mouth reflecting the contribution of alkaline ground waters and eutrophication at the river head. Suspended particles (70–595 mg/l) were enriched in total organic carbon, nitrogen (5–7 times) and metals (1–4 times) relative to bed sediments, but metal concentrations were 2–10 times below the world river’s average. Consistently, metal concentrations in bed sediments were lower than sediment quality guidelines with an increasing downriver trend following the enrichment of clays. The enrichment factors (EF) and geoaccumulation index (Igeo), calculated with local background metal levels from the deepest layers of a dated sediment core, indicate a general prevalence of natural metal sources (EF < 1.5) with unpolluted sediments (Igeo ≤ 0), excepted for the Chivilcoy stream, which showed a significant enrichment of Zn, Cu and Pb (EF = 2–12; 0 ≤ Igeo ≤ 1) constituting a clear pollution hot spot in the basin.

Distribution, ecological risk, and source analysis of heavy metals in recent beach sediments of Sharm El-Sheikh, Egypt.

To study the distribution of the concentrations and the sources of pollutants and their environmental assessment in the Sharm El-Sheikh coastal area, Fe, Mn, Cu, Zn, Pb, Ni, Cd, and Co concentrations were analyzed in the beach sediments of Sharm El-Sheikh harbor and Sharm El-Maya bay by the atomic absorption spectrophotometer. The results revealed that Sharm El-Sheikh harbor has higher concentrations of Fe, Mn, Ni, and Cd than in Sharm El-Maya bay. Meanwhile, the environmental pollution indicators as enrichment factors, metal pollution index, contamination factors, sediments pollution index, geo-accumulation index, ecological risk factor, and the potential contamination index reported that Sharm El-Sheikh harbor has a higher degree of pollution (MPI = 43.4) than Sharm El-Maya bay (MPI = 38.2). Moreover, both of the studied areas have shown very high contamination of Cd and moderate to high contamination of Pb, Mn, Cu, and Zn. Furthermore, the concentrations of Mn, Cu, Ni, and Cd in the studied area are higher than those in the coasts of Hurghada, Shalateen, Red Sea of Saudi Arabia, and the Russian Caspian Sea. The main sources of the metals in the studied area are the human impacts as tourist activities, boat navigation, large numbers of anchored tourist boats, diving operations, and car fuel combustion products. In addition, the natural weathering of Gabal El-Safra and basement rocks can be counted as natural sources of metals.

Economic aspects of metals recover

Abstract One of the modern economy models is circular economy in which wastes should be considered as resource and used in an efficient and sustainable way. This also concerns to metals included in scraps. However, the need for metal recovery from waste is not only the result of the latest economic trends but also the result of large and constantly changing demand for metals. Shrinking natural sources of metals, concentrations of ores in small number of countries in the world and resulting from this dependence on import, geopolitical situation, new technologies demands are only a few most important determinants that have been changing the structure of the metal market over years. In this chapter, authors focused on the presentation of economic aspects of metal recovery from various sources. The chapter presents the characteristic of metal market elements (supply, demand and price) and changes that took place over decades, underlining the structure of precious and highly desirable metal market elements. Balance between the demand and supply ensures price stability and rationalizes inflation. However, growing demand on many means that secure supply chains, such as recycling and material recovery, are essential to ensure continuity in the supply chain and guarantee unrestricted technological progress and innovation. The data included in this chapter presents also the concentration of different metals and group of metals in wastes pointing that recycling of waste can become one of the possibilities of acquiring missing and critical metals. Metal-laden wastes include a few groups: waste electrical and electronic equipments, catalysts of different application, introduced on chemical, petrochemical or automotive market, galvanic wastes and wastewaters. The profitability assessment of recycling processes is very complicated. Nevertheless cited data shows that profitability of recovery depends on the metal analyzed and the type of waste. It must be underline that an optimized management of wastes is of a great importance for the global economy and allow achieving not only economic but also environmental and social benefits.

Metal Contents and Pb Isotopes in the Surface Seawater of the Gulf of Prigi, Indonesia: Detection of Anthropogenic and Natural Sources

In order to investigate the anthropogenic and natural sources of metals in the Gulf of Prigi, Indonesia, it was analyzed their metal contents and Pb isotopes of surface seawater together with sediment, grouper fish, mosh, seaweed, soil, and sharp grass for protecting the environmental pollution of the study area. Samples were leached using a microwave digestion technique. Metal (Ca, Fe, Mn, Cu and Pb) concentrations and 206Pb, 207Pb and 208Pb in the leached solutions were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS). The level concentrations of Ca (491436 µg kg–1), Fe (12123 µg kg–1), Mn (37.2 µg kg–1), Cu (84.0 µg kg–1) and Pb (34.5 µg kg-1) in the surface seawater were low compared with those of background seawater levels issued by World Health Organization (WHO). The range of Pb isotope ratios (207Pb / 206Pb = 0.7966-0.9945 and 208Pb / 206Pb = 2.2600-2.8243) in surface seawater was higher in the plotted Pb growth curve suggesting unpolluted Pb reflected by natural sources such as mineral sources or lithogenic from marine sediment.

Effects of pollution on the geochemical properties of marine sediments across the fringing reef of Aqaba, Red Sea

The Gulf of Aqaba is of significant strategic and economic value to all gulf-bordering states, particularly to Jordan, where it provides Jordan with its only marine outlet. The Gulf is subject to a variety of impacts posing imminent ecological risk to its unique marine ecosystem. We attempted to investigate the status of metal pollution in the coastal sediments of the Jordanian Gulf of Aqaba. The distribution of Cd, Cr, Zn, Cu, Pb, Al, Fe, and Mn concentrations were determined in trapped and bottom-surface sediments at three selected sites at different depths. In addition, monthly sedimentation rates at varying water depths were also estimated at each sampling site using sediment traps. The high concentrations of Cd, Cr, Zn were recorded at the Phosphate Loading Birth (PLB) site followed by the Industrial Complex (IC) site indicating their dominant anthropogenic source (i.e., the contribution of industrial activities). However, Fe, Al, and Mn contents were related to inputs from the terrigenous (crustal) origin. Except for Al, Fe and Mn at the PLB site, the concentrations of metals exhibited a decreasing trend with increasing water depth (distance from the shoreline). The PLB site also showed the highest sedimentation rate which decreased with increasing water depth. The Enrichment factors (EFs) showed that Cd was the most enriched element in the sediment (indicating that Cd pollution is widespread), whereas the least enriched metal in sediments was Cu. EF values suggested that the coastal area is impacted by a combination of human and natural sources of metals, where the anthropogenic sources are intense in the PLB site (north of Gulf of Aqaba). The MSS area is potentially the least polluted, consistent with being a marine reserve. The IC sediments have been found to be impacted by human activities but less intensely compared to the PLB area. These results suggested that there are two sources of metals in sediments; the primary source is likely closer to PLB, while the secondary is nearby the IC.

Climate change enhances the mobilisation of naturally occurring metals in high altitude environments

Manmade climate change has expressed a plethora of complex effects on Earth's biogeochemical compartments. Climate change may also affect the mobilisation of natural metal sources, with potential ecological consequences beyond mountains' geographical limits; however, this question has remained largely unexplored. We investigated this by analysing a number of key climatic factors in relationship with trace metal accumulation in the sediment core of a Pyrenean lake. The sediment metal contents showed increasing accumulation trend over time, and their levels varied in step with recent climate change. The findings further revealed that a rise in the elevation of freezing level, a general increase in the frequency of drier periods, changes in the frequency of winter freezing days and a reducing snow cover since the early 1980s, together are responsible for the observed variability and augmented accumulation of trace metals. Our results provide clear evidence of increased mobilisation of natural metal sources - an overlooked effect of climate change on the environment. With further alterations in climate equilibrium predicted over the ensuing decades, it is likely that mountain catchments in metamorphic areas may become significant sources of trace metals, with potentially harmful consequences for the wider environment.

Lead concentrations and isotope ratios in speleothems as proxies for atmospheric metal pollution since the industrial revolution

Lead concentrations and isotope ratios from two speleothems from the Han-sur-Lesse cave in southern Belgium were measured in order to study the ability of speleothems to act as archives of atmospheric pollution. To address this aim we analyzed trace elemental Al and Pb compositions by LA-ICP-MS and ICP-MS as well as Pb isotopes by MC-ICP-MS. The results help to identify three intervals characterized by particularly high enrichment of Pb: from 1880 to 1905AD, from 1945 to 1965AD, and from 1975 to 1990AD. The speleothem record shows similar changes as the known historical atmospheric pollution level in Belgium. Lead isotope ratios discriminate between Pb sources and confirm that coal and gasoline combustion, combined with regional metallurgical activities, were the predominant Pb pollution sources in the stalagmites during the last 250years. This study opens possibilities to determine anthropogenic versus natural metal sources in well-dated speleothem archives.

Isopods of the genus Ligia as potential biomonitors of trace metals from the gulf of California and pacific coast of the Baja California peninsula.

Supralittoral and high intertidal coastal zones are exposed to pollution from both marine and terrestrial sources and undergo higher deposition rates than the subtidal zone. It is therefore important to identify organisms for this section of the coastal area that can be tolerant to contaminants. The aim of this study was to determine if supralittoral isopods of the genus Ligia can be used as biomonitors, since they are abundant and widely distributed. For this purpose, concentrations of trace elements were determined in Ligia isopods in toto from 26 locations across the Gulf of California and Pacific coast of the Baja California peninsula, which were collected during the summers of 2009 and 2010. The concentrations of trace elements followed the order of; Zn≥Cu>As>Cd>Pb>Hg. Elevated concentrations of copper (up to 1010μg/g) were detected in Ligia from Santa Rosalía (SRo), a locality where industrial mining of copper has historically occurred. Industrial and municipal sewage discharges appear to have contributed to the high concentrations of zinc (326μg/g) and lead (144μg/g) found in organisms from Guaymas location. The high mercury concentration in organisms from Mazatlán (M) (2.01μg/g) was associated with a thermoelectric plant. Natural sources of metals were also detected; coastal upwelling appears to be associated with high cadmium concentrations in Ligia from Punta Baja (PB) (256μg/g) in the Pacific coast, whereas hydrothermal vents may have contributed to high concentrations of arsenic at Ensenada (E) (61μg/g). Our results suggest that Ligia isopods reflect the natural and anthropogenic inputs of trace metals in the environment and could potentially be used as biomonitor organisms of the intertidal rocky shores of the Gulf of California and Pacific coast.

Basin-scale contributions of Cr, Ni and Co from Ortegal Complex to the surrounding coastal environment (SW Europe)

The enrichment of Cr and Ni in the coastal zones is usually associated with anthropogenic sources such as the tanning, galvanization, ceramic, and cement industries. However, geological complexes of specific lithologic composition located near shorelines may act as natural sources of metals to the continental shelf. Cape Ortegal (SW Europe) is an ultramafic complex that has Cr, Ni and Co enriched in rocks due to the minerals chromite, chromospinel, gersdorfite and pentlandite. Thus, the hypothesis that this geological complex contributes to metal enrichment in Ortigueira and Barqueiro Rias and the adjacent continental shelf was tested. Chromium, Ni, and Co were determined in water and in suspended particulate matter of ria tributaries, rainfall, surface sediments, mussels, and algae. High contents of Cr (max. 1670mg·kg−1) and Ni (max. 1360mg·kg−1) were found in the sediments surrounding Cape Ortegal and the Ortigueira Ria as a result of erosion of exposed cliffs. Dissolved Cr and Ni concentrations in fluvial waters were significantly higher in the rivers that crosses the Ortegal Complex, i.e. Lourido (0.47μgCr·L−1; 9.4μgNi·L−1) and Landoi (0.37μgCr·L−1; 4.3μgNi·L−1), in comparison with the nearby basin out of the complex influence (Sor River: <0.01μgCr·L−1; 0.57μgNi·L−1). The annual fluvial contributions of Cr and Ni to the Ortigueira Ria were higher than fluxes into the Barqueiro Ria. Moreover, the increase in Cr and Ni in the rainfall in summer demonstrated the importance of the atmosphere pathway for introducing these elements into the aquatic environment. As a consequence, the contents of these metals in soft tissues and shell of mussels and algae from the Ortigueira Ria were higher than the organisms from Barqueiro Ria. Thus, geological complexes, such as the Cape Ortegal, located in an uncontaminated area, can increase the land–sea exchange of trace metals.

Geologic processes influence the effects of mining on aquatic ecosystems

Geologic processes strongly influence water and sediment quality in aquatic ecosystems but rarely are geologic principles incorporated into routine biomonitoring studies. We test if elevated concentrations of metals in water and sediment are restricted to streams downstream of mines or areas that may discharge mine wastes. We surveyed 198 catchments classified as "historically mined" or "unmined," and based on mineral-deposit criteria, to determine whether water and sediment quality were influenced by naturally occurring mineralized rock, by historical mining, or by a combination of both. By accounting for different geologic sources of metals to the environment, we were able to distinguish aquatic ecosystems limited by metals derived from natural processes from those due to mining. Elevated concentrations of metals in water and sediment were not restricted to mined catchments; depauperate aquatic communities were found in unmined catchments. The type and intensity of hydrothermal alteration and the mineral deposit type were important determinants of water and sediment quality as well as the aquatic community in both mined and unmined catchments. This study distinguished the effects of different rock types and geologic sources of metals on ecosystems by incorporating basic geologic processes into reference and baseline site selection, resulting in a refined assessment. Our results indicate that biomonitoring studies should account for natural sources of metals in some geologic environments as contributors to the effect of mines on aquatic ecosystems, recognizing that in mining-impacted drainages there may have been high pre-mining background metal concentrations.

Metal Pollution Assessment of Surface Sediments Along a New Gas Pipeline in the Niger Delta (Nigeria)

Chromium, nickel, copper, zinc and cadmium were determined in sediments of the Niger Delta (Nigeria) in order to discriminate between natural metal sources and anthropogenic ones. Surface sediments were collected at seven sites along a new gas pipeline near Port Harcourt, between the New Calabar River and the Bonny River towards Bonny town. Chemical characterisation is obtained by hydrofluoric-nitric acid digestion procedure, providing the 'total' ('residual') metal contents. Information about the anthropogenic metal fraction was obtained by cold diluted hydrochloric acid extraction procedure. This 'labile' acid soluble fraction of metals, perhaps due to relatively recent inputs in the sediments, constitutes the fraction more likely to be available to marine organisms, and furnishes a first evaluation of the possible toxicity of sediments of this sensitive ecosystem. Zinc appears to be the most available of all the heavy metals: its 'labile' fraction attains 40-50% of the 'total' zinc in sediment. Sites near Port Harcourt city are the most contaminated. All the examined metals are one order of magnitude below the respective values proposed as a limit for toxicity and are comparable with those observed by other authors in similar Niger Delta areas. Some anomalous data found near Port Harcourt city suggest that zinc and cadmium are the metals that require further monitoring. Their anthropogenic source could be derived from urban and industrial sewage.

Distinguishing between natural and anthropogenic sources of metals entering the Irish Sea

International agreements (e.g. OSPAR) on the release of hazardous substances into the marine environment and environmental assessments of shelf seas require that concentrations and bioavailability of metals from anthropogenic sources can be distinguished from those originating as a result of natural geological processes. The development of a methodology for distinguishing between anthropogenic and natural sources of metals entering the Irish Sea through river inputs is described. The geochemistry of stream, river and estuarine sediments has been used to identify background geochemical signatures, related to geology, and modifications to these signatures by anthropogenic activities. The British Geological Survey (BGS) geochemical database, based on stream sediments from 1 to 2 km 2 catchments, was used to derive the background signatures. Where mining activity was present, the impact on the signature was estimated by comparison with the geochemistry of sediments from a geologically similar, but mining free, area. River sediment samples taken upstream and downstream of major towns were used respectively to test the validity of using stream sediments to estimate the chemistry of the major river sediment and to provide an indication of the anthropogenic impact related to urban and industrial development. The geochemistry of estuarine sediments from surface samples and cores was then compared with river and offshore sediment chemistry to assess the importance of riverine inputs to the Irish Sea. Studies were undertaken in the Solway, Ribble, Wyre and Mersey estuaries. The results verify that catchment averages of stream sediments and major river samples have comparable chemistry where anthropogenic influences are small. Major urban and industrial (including mining) development causes easily recognised departures from the natural multi-element geochemical signature in river sediment samples downstream of the development and enhanced metal levels are observed in sediments from estuaries with industrial catchments. Stream sediment chemistry coupled with limited river and estuarine sampling provides a cost-effective means of identifying anthropogenic metal inputs to the marine environment. Investigations of field and laboratory protocols to characterise biological impact (bioaccumulation) of metals in sediments of the Irish Sea and its estuaries show that useful assessments can be made by a combination of surveys with bioindicator species such as clams Scrobicularia plana, selective sediment measurements that mimic the ‘biologically available’ fractions, and laboratory (mesocosm) studies.

Natural Sources of Metals to the Environment

Almost all metals present in the environment have been biogeochemically cycled since the formation of the Earth. Human activity has introduced additional processes that have increased the rate of redistribution of metals between environmental compartments, particularly since the industrial revolution. However, over most of the Earth's land surface the primary control on the distribution of metals is the geochemistry of the underlying and local rocks except in all but the worst cases of industrial contamination and some particular geological situations. Fundamental links between chemistry and mineralogy lead to characteristic geochemical signatures for different rock types. As rocks erode and weather to form soils and sediments, chemistry and mineralogy again influence how much metal remains close to the source, how much is translocated greater distances, and how much is transported in solutions that replenish ground and surface water supplies. In addition, direct processes such as the escape of gases and fluids along major fractures in the Earth's crust, and volcanic related activity, locally can provide significant sources of metals to surface environments, including the atmosphere and sea floor. As a result of these processes the Earth's surface is geochemically inhomogeneous. Regional scale processes lead to large areas with enhanced or depressed metal levels that can cause biological effects due to either toxicity or deficiency if the metals are, or are not, transformed to bioavailable chemical species.

Long-range atmospheric transport of trace metals: the need for geoscience perspectives

The scientific literature of the past 25 years indicates a lack of consensus over the relative significance of anthropogenic and natural sources of metals in rural and remote ecosystems, meaning areas located several hundred to several thousand kilometers from industrial point sources. Geoscience perspectives are needed to address the critical information gaps associated with this issue, particularly where information on the significance and variability of naturally occurring metals is required. Uncertainties in source apportionment need to be addressed by improving methods of fingerprinting sources of airborne particles, and establishing identities of individual particles on the basis of characteristic morphologies and chemical composition. Further research is required to obtain robust estimates of total metal emissions to the atmosphere and to the oceans in order to determine the relative contribution from anthropogenic sources. Such research must involve a systematic attempt to obtain spatially and temporally representative data on the natural release of metals at the global scale. Moreover, a clear understanding of all local natural and anthropogenic loadings to an ecosystem is required before firm conclusions can be drawn about the relative importance of long-range atmospheric transport.

Controls on As, Pb, and Mn distribution in community soils of an historical mining district, southwestern Colorado

Rico, Colorado is a small mountain community that was developed before the turn of the century around and near underground lead-zinc-silver mines. Today, US regulatory concerns in such communities focus on the metal content, particularly of lead, in community soils. This study integrates bedrock geology, surficial geology, mineralogy and geochemistry in order to define the controls on metal distribution in Rico community soils. The principal constituents of concern are As, Pb, and Mn. The results show that mining-related sources are discrete and localized whereas natural sources, including bedrock (mean Pb content of 3 500 ppm), colluvium (mean Pb content of 1 410 ppm), and older alluvium (mean Pb content of 744 ppm) are wider spread and are the principal sources of metals in Rico community soils. Historical mining sites like Rico should be expected to have significant surficial expressions of mineralized bedrock. In these communities, it is important to accurately define the role of all metal sources as a foundation for determining environmental liabilities, cleanup guidelines, and health risk assessments. The application of geology and mineralogy in support of geochemical characterization is necessary to accurately define the origin and distribution of both anthropogenic and natural metal sources at such sites.

Heavy metal content of meltwaters from the Ross Dependency, Antarctica

Twenty‐eight meltwater samples were collected from Scott Base, Cape Evans, Cape Royds, Marble Point, Vanda Station, and along the length of the Onyx River, in the McMurdo Sound area of Antarctica during the summers of 1992/93 and 1993/94. Samples were analysed for major components, and for heavy metals at ultra‐trace levels. The sample sites included biologically active ponds, glacier melt water, lake water, roadside drains, and rivers. Sample salinities varied widely, but heavy‐metal concentrations were uniformly low except where significant human impacts would have been expected. Concentrations of silver, mercury, lead, copper, cadmium, chromium, nickel, and zinc were higher at Scott Base than in the other areas and were dominantly associated with coarse particulates. Natural sources of metals may be local lithology, but chemical and mechanical processes within the soils and solutions affect the distributions of different metals.