Anthropogenic Metal Pollution Research Articles

Zinc isotope fractionation during the sorption of Zn to minerals and organic matter in sediment cores affected by anthropogenic pollution

Zinc stable isotopes (δ66Zn) serve as a widely fingerprinting tool for detecting anthropogenic Zn contamination. However, there is a limited understanding of δ66Zn behavior during the sorption of Zn to minerals and organic matter. In this study, we have determined the δ66Zn values in specific fractions to investigate their effectiveness in tracing anthropogenic Zn. The revised Community Bureau of Reference (BCR) extraction procedure was applied to a coastal marine core from Osaka Bay and from a lacustrine core from Lake Biwa, both with a history of anthropogenic metal pollution. The δ66Zn values varied from −0.14 ‰ to +1.00 ‰ across the four to five chemical fractions with up to 0.9 ‰ variation within a single horizon. The highest δ66Zn values in the acid-soluble fraction (up to +1.00 ‰) could be explained by the preferential sorption of 66Zn to carbonates and/or the preferential incorporation of 66Zn into calcite. The complex isotopic fractionation during the sorption of Zn to and co-precipitation with Fe–Mn oxyhydroxides likely resulted in an unclear pattern of the δ66Zn values of the reducible fraction. Low δ66Zn values in the oxidizable fraction (Osaka Bay) agree with the 64Zn enrichment in phytoplankton. Higher δ66Zn values of the reducible and oxidizable fractions of the Lake Biwa core indicate that environmental conditions (e.g. ionic strength) and for instance different phytoplankton species or dissolved and suspended particulate matter input drive the Zn isotope fractionation depending on the system (marine vs. lacustrine). The δ66Zn values of the acid-soluble fraction (Osaka Bay and Lake Biwa), of the reducible fraction (only Lake Biwa) and of oxidizable fraction (only Osaka Bay) better reflected the temporal changes in the Zn concentration than the bulk sediment, indicating that these fractions could be a sensitive fingerprinting tool for anthropogenic Zn contamination.

The effect of metal remediation on the virulence and antimicrobial resistance of the opportunistic pathogen Pseudomonas aeruginosa.

Anthropogenic metal pollution can result in co-selection for antibiotic resistance and potentially select for increased virulence in bacterial pathogens. Metal-polluted environments can select for the increased production of siderophore molecules to detoxify non-ferrous metals. However, these same molecules also aid the uptake of ferric iron, a limiting factor for within-host pathogen growth, and are consequently a virulence factor. Anthropogenic methods to remediate environmental metal contamination commonly involve amendment with lime-containing materials. However, whether this reduces in situ co-selection for antibiotic resistance and siderophore-mediated virulence remains unknown. Here, using microcosms containing non-sterile metal-contaminated river water and sediment, we test whether liming reduces co-selection for these pathogenicity traits in the opportunistic pathogen Pseudomonas aeruginosa. To account for the effect of environmental structure, which is known to impact siderophore production, microcosms were incubated under either static or shaking conditions. Evolved P. aeruginosa populations had greater fitness in the presence of toxic concentrations of copper than the ancestral strain and showed increased resistance to the clinically relevant antibiotics apramycin, cefotaxime and trimethoprim, regardless of lime addition or environmental structure. Although we found virulence to be significantly associated with siderophore production, neither virulence nor siderophore production significantly differed between the four treatments. Furthermore, liming did not mitigate metal-imposed selection for antibiotic resistance or virulence in P. aeruginosa. Consequently, metal-contaminated environments may select for antibiotic resistance and virulence traits even when treated with lime.

Variability in mentum deformities of Tanytarsus larvae (Diptera, Chironomidae) in a metal rich basin in Northern Mexico

Mentum deformities in chironomids have been commonly used as indicators of metal contamination in freshwater ecosystems. Incidence of these deformities suggests sublethal effects and can provide early signals of environmental deterioration. While anthropogenic metal pollution is known to lead to an increase in deformities in chironomids, natural background deformity incidence information is key to their effective use as biomonitoring tools. Here we explore the incidence of deformities from 5000 Tanytarsus (Diptera, Chironomidae) menta in relation to water physicochemical, and sediment metal (Al, As, Cu, Fe, Mn, Pb, Zn) concentration data from numerous sites in the naturally metal-rich Sonora River (NW Mexico) obtained over a two-year period. Higher metal concentrations were found in the upper basin. Higher salinity, total suspended solids and conductivity were found in the lower basin. Only As and Cu were occasionally found above published threshold effect levels (TEL). The proportion of deformities (% D) was low (2.1%) and a generalized linear model only explained 25.36% of % D variability among samples; this model included several physicochemical parameters. The only metal significantly related to deformities was Cu. Despite significant spatial and temporal variability in all metal concentrations and other physicochemical parameters in the basin, we were unable to explain a strong relationship between metal concentration and deformity incidence. Our results, based on consistent % D quantification from 5000 samples from a single taxon, suggest that natural variation in metal concentrations, even when statistically significant, is not associated with notable variations in the incidence of deformities.

Photochemistry of foraminiferal test as proxy of Marine Environment, parts of Andhra Coast, East Coast of India

The use of in-coastal environment for monitoring activities such as the marine environment is well known across the world over the years. As a representative of various water-based environmental monitoring activities, many species of foraminifera such as Ammonia have been used. The screening of foraminiferal shell for chemical constituents provides a step forward in determining the ability of benthic foraminifer in the coastal area to react to anthropogenic metal pollution. This study's initial hypothesis is the Foraminifera Calcite Test (Ammonia dentata, Asterorotalia pulchella, Elphidium crispum, Quinqueloculina laevigata, and Massilina secans) binds anthropogenic metals to the structure of the shell and initiates the deformation test. This research uses the normal and abnormal shells of Ammonia specimen. The Ponar collector was used to sample surface sediments. Sophisticated facilities like SEM (Scanning Electron Microscope), EDS (Energy Dispersive X-ray Spectroscopy), and FTIR (Fourier Transform Infrared spectroscopy) detectors have been employed for the analysis of the Foraminiferal shell. For each test (the shooting was done thrice, i.e. first chamber (proloculus), the aperture chamber, and the chambers between the two. The key elements of the foraminifera test are oxygen with an average (weight range of 44.71 - 58.79%) and carbon with an average weight range (10.07 -12.07%). There is a record low level of C element in the abnormal tests.

Evaluation of the Anthropogenic Metal Pollution at Osisko Lake: Sediments Characterization for Reclamation Purposes

The anthropogenic pollution of lake ecosystems by human activities (e.g., mining industries) is recognized as a serious issue. The Osisko urban lake located in Rouyn-Noranda (Quebec, Canada) was used partially as a waste disposal facility for many decades, causing a heavy pollution. The main undertakings of this study are (i) assessing the mineralogical and geochemical properties of lake Osisko sediments, and (ii) studying the pollution that occurred within lake water due to the sediments’ reactivity. Water and sediments across the lake were collected in different sensitive locations. Within the sediment samples, two parts were distinguished: a small layer of black vase over grey sediments. The black vase resembled organic matter while the gray sediment seemed close to clean lake sediments. The collected samples were characterized for their physical (particle size distribution, specific gravity and specific surface area), chemical (minor and major elements as well as total sulfur and carbon) and mineralogical (X-ray diffraction and scanning electron microscope) properties. Additionally, the reactivity of sediments was studied using weathering cells to quantify chemical species leaching and their releasing rates. The results showed that the vase was the only contaminated part with high concentrations of sulfur and metals such as copper, zinc and iron. Geochemical data showed that the composite sample and the vase potentially cause contaminated acid drainage if they are exposed to atmospheric conditions. Indeed, the pH values of the leachates from both samples were between 4 and 6, while those corresponding to sediments remained around circumneutral values. Quantitatively, the contaminant release from the tested samples was variable. Indeed, the Fe cumulative concentrations were around 200, 80 and 20 mg/kg for the vase, composite and sediment samples, respectively. Similarly, the Zn cumulative concentrations were around 4500, 4200, and below the detection limit for vase, composite and sediment samples, respectively. The same tendency was observed for Cu, S, and Fe. Thus, sediments within Osisko lake present a risk for water contamination if they are resuspended or dredged out of the lake. Consequently, they should be stabilized before their disposal. The samples’ high Cu contents also offer the possibility of their reprocessing.

Reconstruction of mining activities in the Western Alps during the past 2500 years from natural archives

The geochemical analysis of natural archives can improve our knowledge of past mining activities and their environmental imprint. The sedimentary records from the Hasli-Aare floodplain (Bernese Alps) over the last 2500 years were analysed for metals. Evidence of past mining contamination was obtained from the XRF analyses of iron, copper, zinc and lead. These results were analytically and statistically processed to produce a metal content index. Positive metal anomalies indicate four major pulses of contamination coinciding with the end of the Iron Age, from the end of the Roman Period to the Early Medieval Period, the Late Medieval Period, and the Modern Period. These pulses show good agreement with local historical sources of mining in the Hasli-Aare catchment, dating back to the beginning of the 15th century. Furthermore, they are in phase with anthropogenic pollution trends inferred from glacier ice cores, lake sediments and peat bogs across the Western Alps, most notably during the Roman, Late Medieval and Modern Periods. However, close comparison between these records can show some differences, suggesting local variations in mining activities and/or a lag in metal transfer. The reconstructed periods of anthropogenic metal pollution are located in their political, economic and social contexts and compared with the climate periods of central Europe.

Multicriteria to estimate the environmental risk of sediment from the Obedska Bog (Northern Serbia), a reservation area on UNESCO's list

The objective of this current study is to compare related sediment legislation standards and norms to the diversity and influence of anthropogenic and natural (geogenic) sources of pollution in the investigated fluvial relief test site region of the Obedska bog. All metals (nickel (Ni), zinc (Zn), cadmium (Cd), copper (Cu) and lead (Pb) except chromium (Cr)) and arsenic (As) have higher values than the Upper Continental Crust (UCC) for loess sediment. Several sharp leaps in the enrichment factor (r) suggested “indicators of anthropogenic metal pollution” for Cd, Cu (r > 5.0) and Zn, Ni (r > 1.0) for this region. In addition, the Chemical Proxy of Alteration (CPA, 60–95) from the unique Jadar block terrane and neighbouring representative catchment areas, confirmed moderate to higher intensity of alteration. Principal Component Analysis/Factor Analysis (PCA/FA) and cluster analysis suggest that Ni, Zn, Cu and Cd are derived from several anthropogenic sources, whereas As is convincingly of geogenic origin, and Pb and Cr exhibit dual origins. The sum of 16 U. S. Environmental Protection Agency Polycyclic Aromatic Hydrocarbons (EPA PAHs) indicated heterogenic sources, but minor effects to biota. The results of the current investigation indicated intensive and highly diffuse sources of pollution in this United Nations Educational, Scientific and Cultural Organization [UNESCO's] region. The outcomes indicate that Cu should be added to the European Union [EU] watch list of emerging contaminants.

Effects of environmental metal pollution on reproduction of a free-living resident songbird, the tree sparrow (Passer montanus)

Anthropogenic metal pollution is known to adversely affect bird reproduction; however, few systematic studies are available on the effects of metal pollution on breeding performance and parental investment in a common resident songbird, the tree sparrow (Passer montanus). We conducted this study in two sites, a long-term heavy metal polluted site (Baiyin [BY]) and a relatively unpolluted site at approximately 110 km distance (Liujiaxia [LJX]), to assess the potential effects of environmental metal contamination on breeding parameters (clutch size, hatching success, fledging success, and growth of nestlings) and parental investment. The results showed smaller clutch size, lower fledging success, and differences in incubation behaviors of tree sparrows in BY than in LJX. Although there was no difference in parental body condition (residual body mass) between the two study sites, the parents responded differently with respect to reproduction due to varying metal levels in their habitats and bodies. Higher Cd levels in the primary feathers of females in BY were associated with lower clutch sizes. Parental investment including incubation duration and feeding rates showed no significant difference between the two sites during the incubation and nestling periods, but the frequencies of incubation visits were higher in BY. Parental behavior during the incubation period was also negatively affected by the parental Pb and Cd levels. Although the nestling growth patterns were relatively similar between the two sites, the nestlings were smaller, had lower body weight, and fledged later and fledging rate was also lower in BY than in LJX. Metal concentrations were higher in nestling organs and feces in BY. Taken together, metal pollution might adversely affect nestling growth condition. Our results suggest a negative response in the reproduction of tree sparrows to long-term environmental metal pollution.

Selection and propagation of IncP conjugative plasmids following long-term anthropogenic metal pollution in river sediments

For a century, the MetalEurop foundry released metals into the river “La Deûle”. Previous work revealed higher microbial diversity in metal impacted sediments, and horizontal gene transfer mediated by conjugative plasmids was suggested to drive the community adaptation to metals. We used an integrative state-of-the-art molecular approach coupling quantitative PCR, conjugation assays, flow cytometry, fluorescence activated cell sorting and 16S rRNA gene amplicon sequencing to investigate the presence of conjugative plasmids and their propagation patterns in sediment microbiomes. We highlighted the existence of a native broad-host range IncP conjugative plasmid population in polluted sediments, confirming their ecological importance for microbial adaptation. However, despite incompatibilities and decreased transfer frequencies with our own alien IncP plasmid, we evidenced that a wide diversity of bacterial members was still prone to uptake the plasmid, indicating that sediment microbial communities are still inclined to receive conjugative plasmids from the same group. We observed that metal pollution favoured exogenous plasmid transfer to specific metal-selected bacteria, which are likely coming from upstream sources (e.g. wastewater treatment plant, farms…). Altogether, our results suggest that MetalEurop sediments are hotspots for gene transfer via plasmids, acting as an “environmental reservoir” for microbes and mobile elements released by human activities.

Teneurs Des Éléments Traces Métalliques Cu, Zn Et Pb Des Sédiments Du Barrage Béni Haroun (Nord-Est De l’Algérie)

This paper focuses on evaluating the degree of three metal pollution (Cu, Zn and Pb) in the sediments of Béni Haroun dam, located in northeastern of Algeria. For this reason, the superficial sediments were sampled at five stations, and the samples were taken at different seasons of the year. The results show low Cu and Zn levels which reflect natural conditions in relation to the area of geological nature. It also highlights the presence of Pb contamination (2.29 to 91.86µg/g). This result was also confirmed by various indices, including the geoaccumulation index (Igeo) and the contamination factor (FC). The Igeo values for Pb show moderate contamination of the Bge2 and Bge3 stations. CF values indicate moderate to considerable contamination for most stations by Pb. However, low or absent of Zn contamination was noted in all stations except for the Bge5. The correlation matrix and the PCA between all metal elements indicates that they were derived from similar sources. The contamination sources would probably establish a significant relationship between runoff and the erosion of agricultural lands. It is therefore an anthropogenic metal pollution related to agricultural activity using fertilizers and pesticides.

Contamination of sediments in the floodplain wetlands of the lower uMngeni River, Kwa-Zulu Natal, South Africa

This study describes the geochemical and physico-chemical characterization of contaminant status of six wetlands of the lower uMngeni River floodplain, KwaZulu-Natal Province, South Africa. At all sites, organic matter content, calcium carbonate and metal concentrations were highest within the fine-sediment dominated surface laminae, decreasing with depth. Exceptions were displayed by arsenic (As), nickel (Ni) and vanadium (V), presumed to be derived from normal geochemical processes. Geochemical indicies indicated high contamination factors for lead (Pb) and V, pointing to moderate anthropogenic metal pollution contribution. Most conspicuous are the contamination high factors for Pb across most sites. Fe and Pb contamination is ubiquitous in all surface laminae, with contamination factors being either border-line, moderate or of high contamination. Enrichment factors for As, Mn and P at site S6 indicate possible anthropogenic sources. The data also shows a possibility of anthropogenic input of P and Zn at site S3. Apart from the enrichment factors established for Ni across all sites, all other metals indicate some degree of enrichment. A range of variable results for the mid to deeper laminae are indicative of natural processes with some human influence. Results of ANOVA confirm the above. Principal component analysis reveals a 46.4% variance from component 1 elements (Al, Ca, Cr, Cu, Fe, Mg, Mn and Zn) and a 17.8% variance from component 2 (Al, Cu and Fe). Given the rapid rate of development in this region, the protection of these floodplain wetlands must receive high conservation priority from the local municipality.

The Response of a 16S Ribosomal RNA Gene Fragment Amplified Community to Lead, Zinc, and Copper Pollution in a Shanghai Field Trial.

Industrial and agricultural activities have caused extensive metal contamination of land throughout China and across the globe. The pervasive nature of metal pollution can be harmful to human health and can potentially cause substantial negative impact to the biosphere. To investigate the impact of anthropogenic metal pollution found in high concentrations in industrial, agricultural, and urban environments, 16S ribosomal RNA gene amplicon sequencing was used to track change in the amplified microbial community after metal contamination in a large-scale field experiment in Shanghai. A total of 1,566 operational taxonomic units (OTUs) identified from 448,108 sequences gathered from 20 plots treated as controls or with lead, zinc, copper, or all three metals. Constrained Analysis of Principal Coordinates ordination did not separate control and lead treatment but could separate control/lead, zinc, copper, and three metal treatment. DESeq2 was applied to identify 93 significantly differentially abundant OTUs varying in 211 pairwise instances between the treatments. Differentially abundant OTUs representing genera or species belonging to the phyla Chloroflexi, Cyanobacteria, Firmicutes, Latescibacteria, and Planctomycetes were almost universally reduced in abundance due to zinc, copper, or three metal treatment; with three metal treatment abolishing the detection of some OTUs, such as Leptolyngbya, Desmonostoc muscorum, and Microcoleus steenstrupii. The greatest increases due to metal treatment were observed in Bacteroidetes, Actinobacteria, Chlamydiae, Nitrospirae, and Proteobacteria (α, β, δ, and γ); the most (relative) abundant being uncharacterized species within the genera Methylobacillus, Solirubrobacter, and Ohtaekwangia. Three metal treatment alone resulted in identification of 22 OTUs (genera or species) which were not detected in control soil, notably including Yonghaparkia alkaliphila, Pedobacter steynii, Pseudolabrys taiwanensis, Methylophilus methylotrophus, Nitrosospira, and Lysobacter mobilis. The capacity to track alterations of an amplified microbial community at high taxonomic resolution using modern bioinformatic approaches, as well as identifying where that resolution is lost for technical or biological reasons, provides an insight into the complexity of the microbial world resisting anthropogenic pollution. While functional assessment of uncharacterized organisms within environmental samples is technically challenging, an important step is observing those organisms able to tolerate extreme stress and to recognize the extent to which important amplifiable community members still require characterization.

Unraveling the impact of chronic exposure to metal pollution through human gallstones

This study aims to explore the impact of chronic metal exposure derived from persistent pollution from mining activity using human gallstones as proxies. The samples were obtained from patients residing in geologically and environmentally contrasting areas in the Province of Huelva, SW Spain, allowing for the evaluation of the regional effect of metal pollution. The study group resides in the Iberian Pyrite Belt characterized by natural and anthropogenic metal pollution from mining activities, whereas the control group resides in the Ossa Morena Zone famous for its natural parks. A total of 68 gallstones were first classified based on their phase composition and structure and subsequently their chemical composition was studied using solution Inductively Coupled Plasma-Mass Spectrometry. The metal concentrations increased in the cholesterol-rich gallstones from pure, to mixed and composite cholesterol stones along with the increasing amount of minor phases, such as bilirubinate, carbonate, and phosphate. These cholesterol stones did not show an evident enrichment tendency. On the contrary, pigment stones, composed of bilirubinate, carbonate, and phosphate phases, were rich in a variety of elements and the regional comparison showed that the pigment stones from the study area were enriched in sulfide-associated metal(loid)s, Mn, Fe, Cu, Zn, Sr, As, Ag, Sb, and Pb with respect to the control group. Inhalation of polluted airborne particulate matter is considered as one of the main exposure routes among the residents of the study area. Additionally, consumption of local water and locally produced food products such as fruit and vegetables and dermal contact may be possible sources of exposure, but no direct connection was observed.

Effects of experimental calcium availability and anthropogenic metal pollution on eggshell characteristics and yolk carotenoid and vitamin levels in two passerine birds

The maternal investment into egg quality depends on the condition of the female, the quality of the mate, and the quality of the environment. In that sense, availability of nutrients and exposure to pollutants are essential parameters to consider. The main aim of this study is to assess the effects of calcium (Ca) availability and anthropogenic metal pollution on early-stage reproduction in two passerine species, great tits (Parus major) and pied flycatchers (Ficedula hypoleuca), inhabiting a Ca-poor and metal-polluted area in SW Finland. Both species were able to obtain sufficient Ca for eggshell formation, and metal pollution was below the level of having negative effects in the egg size and eggshell characteristics. However, metal polluted environment negatively affected yolk lutein and vitamin D3 levels in both species, probably because of a lower access to carotenoid-rich diet and higher metal interference with vitamin D3 metabolism. The higher levels of vitamin D3 in yolks in the unpolluted zone could also be due to upregulated D3 levels as a response to the lower natural Ca availability. Yolk carotenoids and vitamin D3 were positively associated with nestling growth and size, supporting their importance for the appropriate chick development. The interspecific differences in yolk nutrient concentrations possibly reflect the different growth rate of these species. Pied flycatchers are likely adapted to low Ca availability through an efficient vitamin D3 metabolism, but their Ca intake could be close to a deficient level.

Bioaccumulation of trace elements in the sandhopper Talitrus saltator (Montagu) from the Ionian sandy coasts of Sicily

The Ionian beaches of Sicily are of particular ecological interest because they include the basin of the largest active volcano in Europe and hosts both sites subject to natural protection constraints, as well as important industrial settlements. Consequently, the possibilities for these areas to become polluted are numerous.The sandhopper Talitrus saltator has proven to be a good bioindicator of contamination by numerous trace metals on some European coasts. Nevertheless, no data are available for the populations inhabiting the shores of the southern Mediterranean. Now, as metal accumulation has been shown to vary intraspecifically, the aim of this study was to evaluate trace metal accumulation in adults of T. saltator inhabiting Ionian coastal areas of Sicily and make an assessment of natural and anthropogenic metal pollution of this strip of coast. We also extended our survey to As, Co, Mo, Se, Sn and V never investigated before in this species.Significant differences in metal concentration among sites were found in both sand samples and amphipod tissues. The highest metal content was observed near the mouth of Simeto, the longest river of Sicily which collects waters coming from the volcanic territory of Mount Etna. The bioaccumulation of Cd, Cu, Hg and Zn in T. saltator is fully confirmed; it is also proven for As and Mo and assumed for Cr, Fe, Mn and V.Our outcomes let us to evaluate the prevailing influence of telluric contamination of the Ionian sandy shores of Sicily by trace metals. We also come to the conclusion that in the northern sites, pollution originates from volcanic emission while anthropogenic influence prevails in the southern ones.

Contrasted responses of Ruditapes decussatus (filter and deposit feeding) and Loripes lacteus (symbiotic) exposed to polymetallic contamination (Port-Camargue, France)

The use of symbiotic bivalve species to assess the effect of anthropogenic metal pollution was rarely investigated whereas data on filter feeding bivalves are common. The aim of this study was the exposure of two bivalve species, Ruditapes decussatus and Loripes lacteus to polymetallic pollution gradient, originating from harbor activities (Port-Camargue, south of France). Both bivalves differ by their trophic status, filter and deposit feeder for Ruditapes and symbiotic for Loripes that underlies potential differences in metal sensibility. The bivalves were immerged in July (for Ruditapes during 2 and 8days) and in August 2012 (for Loripes during 2, 6 and 8days) in the water column of the harbor, at 3 stations according to pollution gradient. Metal concentrations (Cu, Mn, Zn) in the water column were quantified as dissolved metals (measured by ICP-MS) and as labile metals (measured by ICP-MS using DGT technique). For each exposure time, accumulation of metals in the soft tissue of bivalves (“bioaccumulation”) was measured for both species. In addition, specific parameters, according to the trophic status of each bivalve, were investigated: filtering activity (specific clearance rate, SCR) for Ruditapes, and relative cell size (SSC) and genomic content (FL1) of bacterial symbionts hosted in the gills of Loripes. The SCR of Ruditapes drops from 100% (control) to 34.7% after 2days of exposure in the less contaminated site (station 8). On the other hand, the relative cell size (SSC) and genomic content (FL1), measured by flow cytometry were not impacted by the pollution gradient. Bioaccumulation was compared for both species, showing a greater capability of Cu accumulation for Loripes without lethal effect. Mn, Fe and Zn were generally not accumulated by any of the species according to the pollution gradient. The trophic status of each species may greatly influence their respective responses to polymetallic pollution.

Evaluation of trace metal levels in surface sediments of the Sergipe River Hydrographic Basin, Northeast Brazil

The distributions of Co, Cr, Cu, Mn, Ni, Pb, Fe and Al were investigated in surface sediments collected at 19 sites in the Sergipe River Hydrographic Basin of Northeast Brazil. A regional geochemical baseline (RGB) was defined using iron as a reference element. Enrichment factors (EF) and geoaccumulation indices (Igeo) were used to determine the extent of anthropogenic metal pollution. EF values showed that sediments from sites 1, 5 and 13 could be considered contaminated by Pb, Cr and Cu, respectively. Igeo values showed that only site 13 could be considered contaminated. For other sites, results indicated that naturally occurring metals predominated in the sediments. Possible toxicity related to these metals was examined using the comparing sediment chemical data with sediment quality guidelines (SQG) PEC-TEC values. Principal component analysis (PCA) clearly separated the sites into two groups and hierarchical cluster analysis (HCA) confirmed the interpretations made from the PCA results.

Anthropogenic metal pollution in surface sediments of the Tambaraparni River Estuary

Estuarine sediments in the<63 μm size fraction were collected from 15 stations within the Tambaraparni River Estuary, located on the east coast of India. The distribution of the heavy metals Cd, Co, Cr, Cu, Ni, Pb and Zn was recorded. Our analysis distinguished two groups of elements. First, Cd, Pb and Zn, which occurred in higher than expected concentrations indicative of pollution, and second, Co, Cr, Cu and Ni, which occurred at background levels. The highest metal concentration found in the study area was for Zn (1200 μ g·g−1), and the lowest was for Cd (0.42 μ g·g−1). It is presumed that river run-off, industrial waters and untreated domestic waters are major contributors to heavy metal pollution in the Tambaraparni River Estuary. The concentrations of heavy metal species in surface sediments (<2 m water depth) of the Tambaraparni Estuary were studied to determine the extent of anthropogenic inputs from catchment areas and to understand anthropogenic effects on geochemical process in this tropical estuarine system.

(Pre-) historic changes in natural and anthropogenic heavy metals deposition inferred from two contrasting Swiss Alpine lakes

Continuous high-resolution sedimentary record of heavy metals (chromium (Cr), copper (Cu), lead (Pb), zinc (Zn), manganese (Mn), and mercury (Hg)), from lakes Lucerne and Meidsee (Switzerland), provides pollutant deposition history from two contrasting Alpine environments over the last millennia. The distribution of conservative elements (thorium (Th), scandium (Sc) and titanium (Ti)) shows that in absence of human disturbances, the trace element input is primarily controlled by weathering processes (i.e., runoff and erosion). Nonetheless, the enrichment factor (EF) of Pb and Hg (that are measured by independent methods), and the Pb isotopic composition of sediments from the remote lake Meidsee (which are proportionally more enriched in anthropogenic heavy metals), likely detect early mining activities during the Bronze Age. Meanwhile, the deposition of trace elements remains close to the range of natural variations until the strong impact of Roman activities on atmospheric metal emissions. Both sites display simultaneous increases in anthropogenic trace metal deposition during the Greek and Roman Empires (ca 300 BC to AD 400), the Late Middle Ages (ca AD 1400), and the Early Modern Europe (after ca AD 1600). However, the greatest increases in anthropogenic metal pollution are evidenced after the industrial revolution of ca AD 1850, at low and high altitudes. During the twentieth century, industrial releases multiplied by ca 10 times heavy metal fluxes to hydrological systems located on both sides of the Alps. During the last decades, the recent growing contribution of low radiogenic Pb further highlights the contribution of industrial sources with respect to wood and coal burning emissions.

Does anthropogenic metal pollution affect carotenoid colouration, antioxidative capacity and physiological condition of great tits ( Parus major)?

Although several studies have shown that carotenoid-based signals are negatively affected by (metal) pollution, the underlying mechanisms are not well understood. There are two possible, not mutually exclusive, hypotheses to explain the metal-induced fading of carotenoid colouration. Metal pollution could affect oxidative stress levels and/or the diet. We assessed the expression of the yellow breast of adult and nestling great tits ( Parus major) and related this to physiological parameters in plasma indicative of oxidative stress (total antioxidative capacity) and nutritional condition (albumin, triglyceride, total protein, cholesterol and uric acid concentrations). In four study sites along a metal pollution gradient, both adult and nestling great tits had significantly reduced carotenoid colouration at the most polluted sites. While nestlings' total antioxidative capacity was significantly affected by metal pollution, there was no significant effect on adults' total antioxidative capacity. Both for adult and nestling birds, no clear relation between total antioxidative capacity and carotenoid colouration was found. However, there were significant differences among sites in nutritional parameters, indicating that metal pollution might affect diet composition and quality. We found strong among brood variation in nestlings for all variables (except cholesterol), suggesting that there might be a considerable genetic and/or parental investment factor involved.