Concentrations Of Most Metals Research Articles

HEAVY METALS BIOACCUMULATION IN SELECTED FISH SPECIES OF RIVER GONGOLA AT YAMALTU DEBA, GOMBE STATE, NIGERIA

This study was aimed to determine the level of heavy metals in water and the bioaccumulation factor of heavy metals in selected fish species (Bagrus bayad macropterus, Oreochromis niloticus and Clarias gariepinus) of River Gongola, Gombe State. Water and fish samples were collected from two locations for 18 months (Dec. 2021- May 2023). Water and fish samples were analysed for heavy metals (Cu, Cd, Cr, As, Ni, Mn, Fe and Zn) concentration using an Atomic Absorption Spectrophotometer (AAS). Bioaccumulation factors of heavy metals were determined in the selected fish species. The Cd, As and Mn concentrations in water exceeded the recommended standards. The levels of heavy metals varied significantly among fish organs. The liver had the highest concentration of most metals, followed by the gills and the muscles. The levels of heavy metals in the fish tissues were below standard limits. However, Zn was reported to have the highest concentration in all the tissues studied. The BAF values calculated were mostly < 1, indicating no probability of bioaccumulation except for Fe in B. bayad macropterus and C. gariepinus and As in C. gariepinus Periodic monitoring of the water and biota of the river is recommended to ensure the safety of these resources for consumer use.

STUDY OF SILVER NANOPARTICLES BIOACCUMULATION IN CULTURED RED AND GREEN SEAWEED

The bioaccumulation of polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs) in Palmaria palmata and Ulva sp. seaweed was investigated by ICP-MS and SP-ICP-MS (determination of nanoparticles and size distribution after an enzymatic extraction). Seaweeds were exposed to 0.1 and 1.0 mg L-1 of PVP-AgNPs of small particle size (15 nm) for 28 days. They were cultured in 40-L seawater tanks and nanoparticles were mixed with growing media and the phytoplankton used for feeding. Bioaccumulation changed with the type of seaweed and was not proportional to the concentration. Palmaria palmata and Ulva sp. reached the maximum total Ag concentration at 14 and 21 days of exposure to 1.0 mg L-1, respectively. The Ag concentrations measured (until 0.79 ± 0.06 μg g-1 w.w.) were much smaller than those found in previous studies after short-term exposure (up to 48 h) under laboratory conditions, probably due to the presence of organic matter in the growing media. The maximum concentrations of AgNPs were achieved at 14 and 28 days for Palmaria palmata and Ulva sp., respectively, with most frequent sizes of approximately 20 nm. The size values measured by SP-ICP-MS agreed with TEM sizes in the enzymatic extracts. No changes were observed in the concentrations of most metals (Co, Cr, Cu, Mo, Ni, Rb and V) in exposed seaweed; only a decrease of Cd and Pb at the dose of 1 mg L-1 in Palmaria was observed. Studies simulating the real marine environment are important to estimate bioaccumulation and safety, which change depending on the type of seaweed and nanoparticle.

Investigating the Level of Metal’s Toxicity in Used Cell Phone Batteries by TCLP and WET Methods

Introduction: Batteries are widely used in all kinds of electrical and electronic equipment. These batteries contain several metals that lead to the leakage of metals into the soil and underground water in the burial places, which pose serious risks to human health and the environment. Materials and Methods: In this study, the concentration of 15 metals (Ag, Al, As, Ba, Cd, Co, Cs, Cu, Fe, Li, Mn, Pb, Sr, Zn, Ni) in different components of 7 used battery models was investigated using Waste Extraction Test (WET) and Toxicity Characteristic Leaching Procedure (TCLP) toxicity. The concentration of metals was measured by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Metal concentrations were compared with the United States Environmental Protection Agency (USEPA) and California Department of Toxic Substances Control (CDTSC) standards. Results: The results showed that the average concentration of metals in both WET and TCLP methods was high, but the concentration of most metals in WET method was relatively higher than in TCLP method. Conclusion: The results showed that the recovery of metals from batteries is necessary, moreover safe burial of batteries is essential to reduce environmental risks.

Sources and Specified Health Risks of 12 PM2.5-Bound Metals in a Typical Air-Polluted City in Northern China during the 13th Five-Year Plan.

The continuous monitoring of PM2.5 (including 12 metal elements) was conducted in Jinan, a city with poor air quality in China, during the 13th Five-Year Plan (2016-2020). Positive matrix factorization (PMF) was used to identify emission sources of PM2.5-bound metals, and the health risks of the metals and their emission sources were assessed. During the study period, the concentration of most metals showed a decreasing trend (except Al and Be), and a significant seasonal difference was found: winter > fall > spring > summer. The PMF analysis showed that there were four main sources of PM2.5-bound metals, and their contributions to the total metals (TMs) were dust emissions (54.3%), coal combustion and industrial emissions (22.3%), vehicle emissions (19.3%), and domestic emissions (4.1%). The results of the health risk assessment indicated that the carcinogenic risk of metals (Cr and As) exceeded the acceptable level (1 × 10-6), which was of concern. Under the influence of emission reduction measures, the contribution of emission sources to health risks changes dynamically, and the emission sources that contribute more to health risks were coal combustion and industrial emissions, as well as vehicle emissions. In addition, our findings suggest that a series of emission reduction measures effectively reduced the health risk from emission sources of PM2.5-bound metals.

Below ground chemical and microbial community responses of wood ash addition to a hardwood forest in central Ontario

The use of wood ash as a soil amendment remains restricted in many parts of Canada. To better understand belowground biogeochemical responses to wood ash, soil solution chemistry was measured over 3 years following the application of wood ash (0, 2.5, 5.0, and 7.5 Mg·ha−1) at a hardwood stand in Ontario, after which soil microbial response was assessed using 16S rRNA gene and internal transcribed spacer sequencing. Metal concentrations in the locally sourced wood ash were below provincial regulatory limits. Significant increases in soil solution pH were observed within the forest floor in the first year of the trial, and significant increases in calcium and magnesium were also observed in later years of the trial. Concentrations of most metals in soil water either decreased or exhibited no significant change in response to wood ash. There was an increase in diversity and richness of soil prokaryotic groups in the FH horizon at the highest wood ash treatment that is most likely linked to the large increase in pH. This study indicates that wood ash has a strong ameliorative effect on soil and soil water chemistry without major changes to soil microbial communities and is a viable amendment to forest soils at dosages below 5 Mg·ha−1.

Trace metal pollution gradients in a tropical seagrass ecosystem

Trace metals are one of the most serious pollutants in tropical seagrass meadows given their persistence and toxicity. Whereas quantity is frequently measured, there is no information on the spatial extent of metal pollution in these systems. Here, we use an island in Indonesia (Barang Lompo) as a model system to study the impact radius of two major and eight trace metals in sediment and seagrass leaves. We provide evidence for exponential decay in both the metal pollution index and concentrations of most metals with increasing distance from the island (k = −0.01 to −0.08 m–1). Consequently, there is an impact radius of approximately 100 m around the island. The comparative analysis of both seagrass species further revealed interspecific differences in metal loads. This study highlights the importance of assessing the spatial extent of metal pollution in addition to its quantity.

Potentially Harmful Elements (As, Sb, Cd, Pb) in Soil Polluted by Historical Smelting Operation in the Upper Silesian Area (Southern Poland)

This study aimed at determining the concentration and possibility of migration of potentially harmful elements (PHEs) in soils and mining and metallurgical waste in the Silesian-Cracow region. Our research was carried out in selected locations of Ruda Śląska, Świętochłowice, Bytom, and in the Olkusz region (Bukowno) in southern Poland. The concentrations of metals (e.g., Ag, Ba, Ca, Cd, Cu, Fe, Mg, Mn, Pb, Sr, Zn), metalloids (As, Sb), and sulphur were determined in 33 soil samples (with a depth range of 0.0–0.3 m) and 12 slag samples. These studies show an increased concentration of metals, metalloids, and sulphur, exceeding the level of regional geochemical background. The research results indicate that the degree of the chemical transformation of soils in the analysed regions of Ruda Śląska, Bytom, and Bukowno is advanced. This highlights the high concentrations of most metals, i.e., arsenic, antimony, and sulphur, in the surface layer of soils (topsoil) due to historic Zn-Pb ore mining and Zn and Fe metallurgy. The presence of both primary and secondary metal sulphides, sulphates, carbonates, oxides/hydroxides, silicates, and aluminosilicates was found in the mineral composition of soils and slags.

Potentially Harmful Elements Content in Soil and Stream Sediments in Southwestern Districts of Katowice (Southern Poland) – Geochemical Record of Historical Industrial Plants’ Activity

Abstract The aim of the research was to assess the quality of topsoils and stream sediments in the districts of the Katowice City of southern Poland in the Upper Silesian Industrial Agglomeration, influenced primarily by the exploitation of hard coal deposits and metallurgy. The task was carried out using indicators used to assess anthropogenic soil contamination (contamination factor CF and the Igeo geoaccumulation index), as well as ecotoxicological indicators used to determine the quality of stream sediments (Threshold Effect Concentration TEC and Probable Effect Concentration PEC). In order to indicate the most polluted areas, geochemical maps of selected elements in soil and stream sediments were developed. The material comes from the top layer of soil (0.0–0.3 m) and stream sediments located in the districts of the Katowice City. The work took into account selected potentially harmful elements (PHEs). The concentrations of elements were measured using the ICP-AES method, except for Hg (the CV-AAS method). The values of the CF and Igeo indicators allowed for the indication of high concentrations of most metals, arsenic, and sulfur in the topsoil layer, significantly exceeding the geochemical background values caused by the historical exploitation of Zn-Pb and zinc ores and ferrous metallurgy. The values of the TEC and PEC indicators classify the sediments into categories that may threaten the environment and living organisms.

Transfer of Metals Relevant to the Nuclear Fuel Cycle into Lumbriculus variegatus from Boreal Freshwater Sediments

Radioecological modeling requires information about the transfer of different elements and their radionuclides. These models have traditionally used radionuclide concentrations in water to predict concentrations in aquatic organisms. In addition, these models often assume this accumulation to be linear. In this study, we investigated the transfer of Ba, Co, Ni, Sr, U, and Zn from sediment and artificial freshwater to laboratory-reared benthic Oligochaeta (Lumbriculus variegatus). Total elemental concentrations were used as substitute measurements for specific radionuclides. The radioactive isotopes of these metals are an important part of the nuclear fuel cycle. During various parts of this cycle, they can end up in aquatic environments, mostly at low concentrations. Sediment samples were collected from three small lakes connected to a former uranium mine in Eastern Finland, as well as from a reference lake from a different drainage area nearby. A 28-day bioaccumulation experiment was conducted using collected samples and artificial freshwater. Concentrations measured from sediment, porewater, overlying water, and L. variegatus indicated importance of sediment as a source of uptake for all tested metals. Linear accumulation assumption (constant concentration ratio) also did not appear to be correct for most metals. Metal uptake by L. variegatus seemed to reduce at higher sediment concentrations for most metals, except for Ba and Co. Thus, the common assumptions related to radioecological modeling were not supported by our findings for majority of tested metals and accumulation sources. Further basic research is required to develop more accurate and robust radioecological models.

A 2-year study on the spatio-temporal changes in trace metal concentrations in sediment, water and plants within the Walvis Bay Lagoon, Namibia

Most pristine coastal ecosystems are at threat from pollution due to the increasing anthropogenic activities such as mining, recreational activities, and human settlements that discharge waste as effluents. In Namibia, the Walvis Bay Lagoon is regarded as one of the most important wetlands for birds along the Southern African coast and has been designated as wetland of international importance, which makes its protection from pollution very critical. To date, no studies have focused specifically on the potential accumulation of heavy metals in the Walvis Bay Lagoon environment under the current increase in industrial activities around the lagoon. It is therefore imperative to monitor the changes in industrial pollutants such as toxic heavy metals within the Walvis Bay Lagoon, which is critical in evaluating the overall lagoon ecosystem health. Therefore, this study monitored changes in heavy metals (As, Cr, Cd, Ni, Pb and Zn) in sediment, water and Salicornia spp. plants collected from the Walvis Bay Lagoon. The highest concentrations of the heavy metals were found in the sediment in transects located furthest away from the lagoon mouth, though with values below minimum threshold values. For sediment samples, the maximum average concentration recorded was Cr (31.3 mg/kg); Ni (8.03 mg/kg); Pb (27.9 mg/kg); Zn (59.4 mg/kg); As (6.14 mg/kg); whilst for water samples it was As (0.06 gm/L); Cd (0.11 mg/L); Ni (0.68 mg/L) and Pb (1.49 mg/L). It was noted that the stations further away from the lagoon mouth had higher concentrations of most metals, indicating the importance of lagoon recharge and discharge. Sedimentation with clay in areas furthest away from the lagoon mouth could be resulting in higher heavy metal retention within the lagoon and thus periodic monitoring of both heavy metals and clay sedimentation is required. Based on this baseline data, the heavy metal concentrations within the lagoon indicate a healthy lagoon, with no immediate risk posed by the heavy metals. However, this study was only undertaken over two years and more time will be required to monitor the long-term changes in these trace metals to have more policy influencing data, hence continued monitoring is recommended. Monitoring of sediment, water and plants should also be coupled with sampling of organisms like fish, crustaceans and birds, that are found within the lagoon to evaluate any correlations between the source concentrations and that in the organisms.

Assessment of metal pollution in sediment and its impact on the macrobenthic community of Richards Bay Harbour, South Africa

Port and industrial activities often cause contamination of estuarine sediments, yet information on sediment metal contamination in Richards Bay Harbour is limited. This study examined the extent and ecological relevance of metal contamination using sediment quality guidelines, pollution indices, macrobenthic community structure and the biotic index M-AMBI. Sediment samples for metal and macrobenthic analyses were collected quarterly at seven sites during 2016−2017 using a Van Veen sediment grab sampler. Sediment samples were acid digested using a microwave digester and analysed for metal concentrations using ICP-OES. Highest metal concentrations (Cd, Cr, Cu, Ni and Zn) were associated with areas most affected by industrial activities, while concentrations of most metals at the remaining sites were low. Pollution indices confirmed significant enrichment of Cd, Cr and Cu in bulk terminal sediment. Sediment quality guidelines revealed potential toxicity associated with Cu, Cr and Ni. The dominant taxa were Halmyrapseudes digitalis (two sites), Mediomastus capensis (three sites) and Sigambra parva (two sites). A significant inverse correlation existed between pollution indices and M-AMBI scores, confirming the adverse effect of metals on habitat quality. The need for a biomonitoring programme incorporating relevant biotic and abiotic indices is emphasised to assess the long-term effects of sediment contamination on aquatic communities in South African estuarine environments.

Sediment Contamination and Toxicity in the Guadalquivir River (Southwest, Spain)

A segment of the Guadalquivir River was assessed between the Alcalá del Río dam and Seville through an integrative sediment quality assessment. Chemical concentrations of metals and toxicity under laboratory conditions were used as lines of evidence. A battery of bioassays with four organisms (the amphipod Ampelisca brevicornis, the bacteria Vibrio fischeri, the sea urchin Paracentrotus lividus, and the oligochaete Tubifex tubifex) exposed to sediment made it possible to determine the potential risk associated. The sediments from Seville and Alcalá del Río showed higher values of the concentration of most metals than the Algaba station, with Cu (35–37 µg/g), Zn (70–75 µg/g), Ni (23–26 µg/g), and Pb (27–30 µg/g) being the most abundant metals. An increasing toxicity gradient was shown downstream among the bioassays with the amphipod A. brevicornis, the fertilization test using the sea urchin P. lividus, and the freshwater worm growth T. tubifex. Conversely, an increasing toxicity gradient was shown upstream in the embryo-larval P. lividus development. The link between sediment contamination and toxicity makes it possible to obtain a gradient of contaminant concentration comparable with nationally and internationally widely accepted sediment quality guidelines in order to establish the risk associated with this area of study.

A comparison of metal distribution in surface soil between wetland and farmland in the Sanjiang plain

The transformation from wetland to farmland is in vigorous process to gain more grain production. Meanwhile, restoring wetland from farmland is going on due to the important ecological function of wetland. To understand the ecological risk which might happen in these transform processes, the 18 kind of metals and SOM were analyzed in 25 wetland sites and 7 farmland sites from Sanjiang Plain. Results showed that the concentration of most metals in wetland was lower than that in farmland in generally and SOM was higher in wetland. According to Geo-accumulation index, there were no pollution for most metals. Metal pollution risk in farmland was generally higher than that in wetland except Cu and Zn. Parent rocks, flooding conditions and vegetation types were the main metal sources for wetland. For farmland, anthropogenic activities were the major metal sources. Metal distribution should be taken seriously to avoid metal pollution when land use was changed.

Assessment of contaminants in blue sharks from the Northeast Atlantic: Profiles, accumulation dynamics, and risks for human consumers

Chemical pollution is a major threat to marine ecosystems, and top predators such as most shark species are extremely vulnerable to being exposed and accumulating contaminants such as metals and persistent organic pollutants (POPs). This work aimed to study the degree, composition, and the sources of contamination in the blue shark (Prionace glauca) inhabiting the Northeast Atlantic, as well as the potential risk faced by human consumers. A total of 60 sharks were sampled in situ aboard fishing vessels, and the concentrations of a set of metals and POPs were analysed in various tissues and complemented with stable isotope analyses. High levels of contaminants were found in most sharks sampled. The concentrations of most metals were higher in the muscle when compared with the liver. Regarding the dangers to consumers posed by the concentrations of arsenic (As), mercury (Hg), and lead (Pb), over 75% of the sharks presented muscle concentrations of at least one contaminant above the legal limits for human consumption, and a risk assessment determined that consumption of meat of these sharks exceeding 0.07 Kg per week could potentially expose human consumers to dangerous amounts of methylmercury (MeHg). Additionally, the assessment of single contaminants may lead to an underestimation of the risk for the human health. Finally, the overall accumulation of contaminants seems to be mostly influenced by the sharks’ geographical distribution, rather than sex, size, or trophic level of their prey.

Characteristics and influencing factors of metal distribution in different wetlands of the Liaohe Delta, Northeastern China

Metal distribution in different wetlands under the complex influence of natural and anthropogenic activities in the Liaohe Delta was analyzed to better protect and manage delta areas. Ninety-six soil samples were collected from six wetland types, and the levels, depth distributions, risk, and influencing factors of metals (i.e., As, Cd, Cr, Ni, Cu, Pb, Zn, Mn, Al, and Fe) were analyzed. The results showed that the concentrations of As, Cd, Cr, Ni, Zn, and Al in more than 70% of the soil samples were higher than the background value of Liaoning Province. The concentration of As decreased with distance from the estuary, while that of Cr was higher downstream of Liaohe. The spatial distributions of Cd, Ni, Cu, Pb, and Zn were similar. The concentrations of most metals in the topsoil were higher than those in the subsoil. According to the Nemerow pollution index, higher pollution was observed in the area far away from the Liaohe River and Bohai Sea for the topsoil layer, while for the subsoil layers, higher pollution was observed in the area near the Liaohe estuary. The correlation analysis showed that the wetland type was clearly correlated with Cd, Cu, Al, and S. The concentrations of Cd, Pb, Zn, C, N, P, and S and the electrical conductivity obviously decreased with soil depth, while the concentration of Mn was positively correlated with soil depth. Mn was negatively correlated with total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP), whereas Cd, Pb, and Zn showed positive correlation with TOC, TN, and total sulfur (TS). The general linear model indicated that wetland type had a significant effect on As, Cd, Ni, Cu, Pb, Zn, Al, and Fe (p< 0.01), while depth had a significant effect on Cd, Cr, and Pb (p< 0.01). The findings of this work will contribute to pollution control and ecosystem health conservation of the Liaohe Delta.

Metals, PAHs and oxidative potential of size-segregated particulate matter and inhalational carcinogenic risk of cooking at a typical university canteen in Shanghai, China

Cooking is an important source of indoor emissions, and exposure to cooking emissions can instigate adverse health effects. Oxidative potential (OP) is a good indicator for assessing health risk, but studies detecting the OP of cooking emissions are rare. In this paper, size-segregated samples were collected at four sites in the canteen to study the chemical characteristics and OP of particulate matter (PM) emitted from cooking. The four sites were set to study the effects of different cooking styles and kitchen types. The results showed that the concentrations of most metals, water-soluble ions, PAHs, and OP at four sites followed the trend: deep-frying > stir-frying > second floor hall > first floor hall. And the concentration at the fine fraction (PM0.056-3.2) was much higher than that at coarse fraction (PM3.2-18). The PM OP at four sites were 1.1642 nmol m−3·min−1, 1.2088 nmol m−3·min−1, 0.8589 nmol m−3·min−1 and 0.9507 nmol m−3·min−1, respectively. The correlation between OP and other components showed that Zn (|r| = 0.444) and DBA (|r| = 0.507) were moderately related to OP, which suggested that heavy metals and PAHs might be contributed to PM OP. The carcinogenic risk assessments of heavy metals and PAHs showed that, there might be an increasing of potential carcinogenic risk if exposure to cooking environment for lifetime. Our results were firstly helpful for PM characteristics researches on cooking emissions, and also significant to public health protection, especially for people who usually cook.

Adaptive Redox Reactions Promote Naturalization of Rare Orchid Epipactis atrorubens on Serpentine Dumps Post Asbestos Mining

Epipactis atrorubens (Hoffm.) Besser. is a regionally rare orchid species with highly ornamental properties due to its very beautiful bright flowers, therefore it is of considerable interest as a horticultural plant for use in botanical gardens and greenhouses. The objective of the research was to assess metal accumulation and some pro- and antioxidant reactions in E. atrorubens, colonizing serpentine dumps post asbestos mining. Additionally, some physicochemical properties of substrates, microbiotic characteristics and water status were investigated in orchids growing on two serpentine dumps and in a natural forest habitat of the Middle Urals, Russia. The dump substrates were characterized by the strong stoniness and the high content of Mg, Ni, Cr and Co (by 1.8 times on average) compared to the natural habitat. In these sites, E. atrorubens was characterized by increased mycorrhization. In the rhizome and roots of E. atrorubens the concentrations of most metals studied were considerably higher (more than 4 times on average) than in the leaves. It was found that orchids colonizing serpentine dumps produced more lipid peroxidation products (by 1.4 times on average) in the leaves which was accompanied by the more active synthesis of such non-enzymatic antioxidants as ascorbate, free proline, soluble phenolic compounds (including flavonoids) and non-protein thiols. The study suggests that non-enzymatic antioxidants increased the adaptive potential of E. atrorubens and contributed to its naturalization on serpentine dumps post asbestos mining.

Are Fresh Water and Reclaimed Water Safe for Vegetable Irrigation? Empirical Evidence from Lebanon

The use of polluted water to irrigate is an increasing problem in the developing world. Lebanon is a case in point, with heavily polluted irrigation waters, particularly in the Litani River Basin. This study evaluated the potential health risks of irrigating vegetables (radishes, parsley, onions, and lettuce) using three water sources (groundwater, river water, and treated wastewater) and three irrigation methods (drip, sprinkler, and surface) over two growing seasons in 2019 and 2020. Water, crop, and soil samples were analyzed for physicochemical parameters, pathogens, and metals (Cu, Cd, Ni, Cr, and Zn). In addition, the bioaccumulation factor, estimated dietary intakes, health risk index, and target hazard quotients were calculated to assess the health risk associated with metal contamination. The study showed that, for water with less than 2 log E. coli CFU/100 mL, no pathogens (Escherichia coli, salmonella, parasite eggs) were detected in irrigated vegetables, irrespective of the irrigation method. With over 2 log E. coli CFU/100 mL in the water, 8.33% of the sprinkler-and surface-irrigated vegetables, and 2.78% of the drip-irrigated root crops (radishes and onions), showed some degree of parasitic contamination. E. coli appeared only on root crops when irrigated with water having over 3 log CFU/100 mL. The concentrations of most metals were significantly lower than the safe limits of the FAO/WHO of the Food Standards Programme Codex, except for zinc and chromium. The trends in the bioaccumulation factor and the estimated dietary intakes of metals were in the order of Cu < Cd < Ni < Cr < Zn. The target hazard quotient values for all metals were lower than 1.0. Under trial conditions, the adoption of drip irrigation with water with less than 3 log E. coli CFU/100 mL proved to be safe, even for vegetables consumed raw, except for root crops such as onions and radishes that should not be irrigated with water having over 2 log E. coli CFU/100 mL. Treated wastewater had no adverse effect on vegetable quality compared to vegetables irrigated with other water sources. These results support efforts to update the Lebanese standards for water reuse in agriculture; standards proposed in 2011 by the FAO, and currently being reviewed by the Lebanese Institution of Standards. This research will inform a sustainable water management policy aimed at protecting the Litani River watershed by monitoring water quality.

Heavy metal uptake of nearshore benthic foraminifera during multi-metal culturing experiments

Abstract. Heavy metal pollution originating from anthropogenic sources, e.g. mining, industry and extensive land use, is increasing in many parts of the world and influences coastal marine environments even after the source has ceased to pollute. The elevated input of heavy metals into the marine system potentially affects the biota because of their toxicity, persistence and bioaccumulation. An emerging tool for environmental applications is the heavy metal incorporation into foraminiferal calcite tests, which facilitates monitoring of anthropogenic footprints on recent and past environmental systems. The aim of this study was to investigate whether the incorporation of heavy metals into foraminifera is a direct function of their concentration in seawater. Culturing experiments with a mixture of dissolved chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), cadmium (Cd), tin (Sn), mercury (Hg) and lead (Pb) in artificial seawater were carried out over a wide concentration range to assess the uptake of heavy metals by the nearshore foraminiferal species Ammonia aomoriensis, Ammonia batava and Elphidium excavatum. Seawater analyses revealed increasing concentrations for most metals between culturing phases and high metal concentrations in the beginning of the culturing phases due to sudden metal addition. Furthermore, a loss of metals during the culturing process was discovered by an offset between the added and the actual concentrations of the metals in seawater. Laser ablation ICP-MS (inductively coupled plasma mass spectrometry) analysis of the newly formed calcite revealed species-specific differences in the incorporation of heavy metals. The foraminiferal calcite of all three species exhibited Pb and Ag concentrations strongly correlated with concentrations in the seawater culturing medium (partition coefficients and standard deviation for Ag – Ammonia aomoriensis, 0.50 ± 0.02; Ammonia batava, 0.17 ± 0.01; Elphidium excavatum, 0.47 ± 0.04; for Pb – Ammonia aomoriensis, 0.39 ± 0.01; Ammonia batava, 0.52 ± 0.01; Elphidium excavatum, 0.91 ± 0.01). Ammonia aomoriensis further showed a correlation with Mn and Cu, A. batava with Mn and Hg, and E. excavatum with Cr and Ni and partially also with Hg. However, Zn, Sn and Cd showed no clear trend for the species studied, which in the case of Sn was maybe caused by the lack of variation in the seawater Sn concentration. The calibrations and the calculated partition coefficients render A. aomoriensis, A. batava and E. excavatum as natural archives that enable the determination of variations in some heavy metal concentrations in seawater in polluted and pristine environments.

Tissue-specific distribution and bioaccumulation pattern of trace metals in fish species from the heavily sediment-laden Yellow River, China

The Yellow River is one of the largest contributors to the global riverine sediment flux from the land to the ocean. Tissue-specific bioaccumulation of trace metals in fish from heavily sediment-laden rivers remains unclear to date. The concentrations and distributions of trace metals in water, suspended matters, sediments, and various fish tissues were investigated in the mainstem of the Yellow River were investigated. The concentrations of most metals in abiotic media were high in the Gan-Ning-Meng of upstream and downstream segments, and were highest in fine-sized suspended matters. The highest concentrations of most metals were in the gill and liver, followed by the gonad, and lowest in the muscle, and there were a significant overall differences among the tissues. The concentrations of metals in some tissues (e.g., muscle and gill) significantly differed among regions and feeding habits. The highest values of the bioaccumulation factor for suspended matters (BFSPM) were observed in the midstream region (e.g., reaching to 19.0 for Se in the liver). This was determined by metal type and tissue specificity, food composition, and concentration of metals in abiotic media. The results highlight the significance of suspended matters for the distribution of trace metals in abiotic and biotic media.