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Particulate phases transport trace metals (TM) and thereby exert a major control on TM distribution in the ocean. Particulate TMs can be classified by their origin as lithogenic (crustal material), biogenic (cellular), or authigenic (formed in situ), but distinguishing these fractions analytically in field samples is a challenge often addressed using operational definitions and assumptions. These different phases require accurate characterization because they have distinct roles in the biogeochemical iron cycle. Particles collected from the upper 2,000 m of the northwest subtropical Atlantic Ocean over four seasonal cruises throughout 2019 were digested with a chemical leach to operationally distinguish labile particulate material from refractory lithogenics. Direct measurements of cellular iron (Fe) were used to calculate the biogenic contribution to the labile Fe fraction, and any remaining labile material was defined as authigenic. Total particulate Fe (PFe) inventories varied <15% between seasons despite strong seasonality in dust inputs. Across seasons, the total PFe inventory (±1SD) was composed of 73 ± 13% lithogenic, 18 ± 7% authigenic, and 10 ± 8% biogenic Fe above the deep chlorophyll maximum (DCM), and 69 ± 8% lithogenic, 30 ± 8% authigenic, and 1.1 ± 0.5% biogenic Fe below the DCM. Data from three other ocean regions further reveal the importance of the authigenic fraction across broad productivity and Fe gradients, comprising ca. 20%–27% of total PFe. Plain Language Summary: The availability of dissolved iron controls phytoplankton growth in much of the ocean. Most oceanic iron is contained in particles that are a mixture of live and dead cells (biogenics), crustal material (lithogenics), and minerals that have precipitated in seawater (authigenics). Each of these materials has different chemical properties that determine how iron cycles through the ocean and regulate how much iron is available for uptake by phytoplankton. Specifically, authigenic and biogenic forms are more accessible to phytoplankton but are often measured as one fraction despite formation by different processes. We measured different forms of iron in particles across seasons and environmental gradients and found that 20%–30% of iron is authigenic. Key Points: Iron in phytoplankton accounts for <80% of chemically labile Fe and does not exceed 0.1 nMBiogenic Fe is a small and relatively invariant component of particulate Fe (PFe) pools, even across seasonal and regional gradientsAuthigenic Fe is a significant fraction of particulate Fe across seasons and productivity gradients [ABSTRACT FROM AUTHOR]

ABSTRAK Pantai Sampulungan merupakan salah satu pantai di Kabupaten Takalar, Sulawesi Selatan sebagai kawasan wisata. Aktivitas pengunjung di pantai ini dapat mempengaruhi kualitas pasir besi. Dengan demikian, perlu dilakukan investigasi sifat magnetik pasir besi dan hubungannya dengan logam berat. Studi ini bertujuan menganalisis sumber mineral magnetik serta hubungan suseptibilitas magnetik dan logam berat pasir besi Pantai Sampulungan. Pengukuran parameter magnetik seperti suseptibilitas magnetik menggunakan alat Bartington Susceptibility Meter dilengkapi sensor MS2B. Metode XRF digunakan untuk identifikasi logam berat. Hasil menunjukkan bahwa mineral yang terkandung pada pasir besi bersifat ferimagnetik. Sumber mineral magnetik pada pasir besi dominan berasal dari proses pelapukan batuan secara alami atau litogenik. Hubungan suseptibilitas magnetik dan logam berat memiliki korelasi positif kuat. Kata kunci: suseptibilitas magnetik; logam berat; korelasi positif; litogenik; pantai sampulungan. ABSTRACT Sampulungan Beach is one of the beaches in Takalar Regency, South Sulawesi, as a tourist area. Visitor activities on this beach can affect the quality of the iron sand. Thus, it is necessary to investigate the magnetic properties of iron sand and its relationship with heavy metals. This study aims to analyze the magnetic mineral resources and the relationship between magnetic susceptibility and the heavy metal iron sand of Sampulungan Beach. Measurement of magnetic parameters such as magnetic susceptibility uses a Bartington Susceptibility Meter equipped with an MS2B sensor. The XRF method is used to identify heavy metals. The results show that the minerals contained in the iron sand are ferrimagnetic. Iron sand's dominant magnetic mineral source comes from natural or lithogenic rock weathering processes. The relationship between magnetic susceptibility and heavy metals has a strong positive correlation. Keywords: magnetic susceptibility; heavy metal; positive correlation; lithogenic; sampulungan beach.

Abstract The present study was conducted for the spatial distribution and concentration evaluation of heavy metals, including Cu, Cd, Mn, Fe, Zn, and Pb, within 102 soil samples collected from Kushk Mine in Bafgh, Iran. This work employed hierarchical clustering analysis (HCA), principal component analysis (PCA), and spatial distribution patterns, to perform element distribution evaluation within the area. The distributions of heavy metals in the entire area were exhibited in the form of maps. The average concentrations of Cd, Cu, Mn, Fe, Zn, and Pb were found to be 0.39, 0.26, 5.3, 4.1, 51.9, and 40.9 mg.kg−1, respectively. Based on the PCA and HCA findings, the heavy metals were divided into two groups. The first group included Pb, Cd, Zn, and Cu. In the first group, altered threshold‐surpassing anthropogenic and lithogenic pollution was found to be the main factor accounting for Pb and Zn. The second group involved Fe and Mn, which could be impacted by either anthropogenic and lithogenic factors. Furthermore, the geo‐statistical results demonstrated higher contents of the heavy metals in the south of the mine and in the vicinity of the mine tailings. It may be concluded from the results that the heavy metal contents of the area are impacted by anthropogenic and lithogenic factors.

The Svalbard archipelago is a glacial environment bestowed with various lakes that act as a natural archive for understanding environmental conditions. The accumulation of sediments in lake basins and their distribution are affected by different mechanisms. Therefore, to understand the distribution of sediments, factors controlling the transport and metal enrichment in the lake environment, core sediments were studied from four lakes (L-A, L-1, L-2 and L-3). Also, the potential ecological risk index (PERI) was computed to determine the impact of metal enrichment on the sediment-associated biota. The results obtained showed that the distribution of trace elements was mainly controlled by the major elements like Al, Ti, Fe, and Mn attributed to their lithogenic origin. Index of geoaccumulation (Igeo) of all four lakes showed a moderate level of enrichment of metals like Cr and Cd indicating an enhanced supply of these metals probably from the catchment rocks and anthropogenic activities. A comparison of metals with Arctic Sediment Quality Guidelines (ASQGs) showed that Cd, Cr and Cu were enriched in the sediments of all the cores indicating the occurrence of adverse biological effects. Furthermore, a potential ecological risk index (PERI) revealed high Cd indicating considerable potential ecological risk to the sediment-associated biota. Thus, trace element influx to the lakes needs to be monitored with due emphasis on Cd contamination. [ABSTRACT FROM AUTHOR]

The present study was conducted for the spatial distribution and concentration evaluation of heavy metals, including Cu, Cd, Mn, Fe, Zn, and Pb, within 102 soil samples collected from Kushk Mine in Bafgh, Iran. This work employed hierarchical clustering analysis (HCA), principal component analysis (PCA), and spatial distribution patterns, to perform element distribution evaluation within the area. The distributions of heavy metals in the entire area were exhibited in the form of maps. The average concentrations of Cd, Cu, Mn, Fe, Zn, and Pb were found to be 0.39, 0.26, 5.3, 4.1, 51.9, and 40.9 mg.kg−1, respectively. Based on the PCA and HCA findings, the heavy metals were divided into two groups. The first group included Pb, Cd, Zn, and Cu. In the first group, altered threshold‐surpassing anthropogenic and lithogenic pollution was found to be the main factor accounting for Pb and Zn. The second group involved Fe and Mn, which could be impacted by either anthropogenic and lithogenic factors. Furthermore, the geo‐statistical results demonstrated higher contents of the heavy metals in the south of the mine and in the vicinity of the mine tailings. It may be concluded from the results that the heavy metal contents of the area are impacted by anthropogenic and lithogenic factors. [ABSTRACT FROM AUTHOR]

The objective of this study was the determination of major and trace elements in the bee pollen samples from the whole territory of Republic of Kosovo. Pollen, as a natural plant product, is exposed to different contaminations absorbed by plants from the soil through the root system or with water intake, as well as to pollutants of different origins, including anthropogenic ones, deposited directly on pollen. In total 67 pollen samples were collected in 2019. The samples were analyzed for 27 macro and microelements by using ICP-AES and ICP-MS. The mean content of major elements in bee pollen was 4065, 3455, 1375 and 549 mg/kg for K, P, Ca and Mg, respectively. The range of the contents for some potentially toxic elements was 11.9-139.1, 1.9-16, 0.11-6.25, 0.01-0.329 and 0.001-0.38 mg/kg for Zn, Cu, Pb, Cd and As, respectively. Three groups of elements of mixed origin were identified through factor analysis: the first and the third Factors, are mostly of geogenic origin (Ag, Li, Al, Fe, Ca, Sr, K, Mg and P and Co, Ni, Cr, Cu and Mn) and the second Factor association is related to anthropogenic processes (Sb, As, Pb, Tl, Sn and Cd). [ABSTRACT FROM AUTHOR]

In this paper, we present, describe, and model the first size-fractionated (0.8–51 µm; >51 µm) water-column particulate trace metal results from the US GEOTRACES North Atlantic Zonal Transect in situ pumping survey, with a focus on the lithogenic tracer elements Al, Fe and Ti. This examination of basin-wide, full-depth distributions of particulate elements elucidates many inputs and processes—some for bulk lithogenic material, others element-specific—which are presented via concentration distributions, elemental ratios, size-fractionation dynamics, and steady-state inventories. Key lithogenic inputs from African dust, North American boundary interactions, the Mediterranean outflow, hydrothermal systems, and benthic nepheloid layers are described. Using the refractory lithogenic tracer Ti, we develop a 1-D model for lithogenic particle distributions and test the sensitivities of size-fractionated open-ocean particulate Ti profiles to biotically driven aggregation, disaggregation rates, vertical sinking speeds, and dust input rates. We discuss applications of this lithogenic model to particle cycling in general, and to POC cycling specifically.

Thorium (Th) isotopes were applied to quantify the supply of lithogenic inputs from the Kerguelen Plateau to the Southern Ocean. The dissolved concentrations of 232Th and 230Th were measured following a novel pre-concentration method using the Nobias resin from 10 stations above and on the slopes of the plateau. Elevated 232Th/230Th ratios in the upper 500 m of the water column confirm the input of lithogenic material from islands, glaciers and the resuspension of shelf-deposited sediments. 230Th concentrations were used to calculate a scavenging residence time for Th, which was then applied to calculate the flux of dissolved 232Th required to match the observed concentrations of dissolved 232Th. The 232Th content of the lithogenic material from the Kerguelen Plateau was used with the solubility of Th reported in the literature, to estimate a lithogenic particle flux of 7 to 810 mg m–2 day–1. This flux is comparable to fluxes obtained using sediment traps (8–777 mg m–2 day–1) in other continental-margin zones of the Southern Ocean. The flux of dissolved iron, generated by the dissolution of particles, was also calculated (4,189–6,800 nmol m–2 day–1) based on the iron/thorium ratio in the material from the Kerguelen Plateau. This is higher than previous estimates (1,342 nmol m–2 day–1), suggesting the dissolution of particles as the missing source of iron, thus closing the iron budget of the region. This study confirms the utility of long-lived Th isotopes to quantify lithogenic inputs from continental margin settings.

Increasing demographic pressure in the area around the Mounts Kupe and Manengouba (Cameroon) is leading to increased agricultural activities with potential heavy metal pollution problems. Concentrations of twelve trace elements (TEs) in five Andosols and one Cambisol developed on tephra of ages varying from 6.61 ± 0.17 to 0.01 ± 0.12 Ma of the mounts mentioned above were determined and their correlation relationships with selected soil physico–chemical (organic matter (OM), , pHKCl, pHNaF, oxalate extractable Al, Fe, Si, pyrophosphate extractable Al, allophane and ferrihydrite contents) properties evaluated. Alkaline fusion was used to bring the elements in solution followed by elemental detection through ICP–OES. Results showed that average concentrations (ppm) of the TEs increased in the following order: Be, Bi (<5) ≈ Cd, Pb (<10) < Co (54 ± 13), Cu (60 ± 23) < S (109 ± 140), Ni (119 ± 51), Zn (125 ± 17), Cr (152 ± 69), Sr (197 ± 133) < Ba (472 ± 224). Vertical distribution of TEs was irregular, except for S accumulated in topsoil. Ba, Sr, and Zn are associated to OM and allophane according to correlation analysis. Cr, Co, Cu and Ni are apparently more related to OM and pH, while S appears to be related to OM only. In both the Andosols and Cambisol, TEs are dominantly lithogenic. Relationships between TEs indicated that Ba is associated to Zn, Co to Cr, Cu and Ni, Cr to Cu and Ni, while Cu is associated to Ni. Status of TEs in these soils will provide more critical information to environmentalists for pollution monitoring. This study provides baseline data on TE concentrations and distribution in tephra soils of the humid tropics in Africa where a paucity of such data exists. [ABSTRACT FROM AUTHOR]

Carpobrotus dimidiatus is an indigenous South African medicinal plant species from the Aizoaceae family that bears edible fruit that is consumed for nutritional value. In this study, the elemental distribution in C. dimidiatus fruit and growth soil from fifteen sites in KwaZulu-Natal (South Africa) was determined along with soil pH, soil organic matter and cation exchange capacity, to assess for nutritional value and the effect of soil quality on elemental uptake. The results showed elemental concentrations in fruit to be in decreasing order of Ca (6235–32755 mg kg−1) > Mg (2250–5262 mg kg−1) > Fe > Mn > Zn (20.9–50.6 mg kg−1) > Cu (3.83–20.6 mg kg−1) > Pb > Cr > Cd > As ∼ Co ∼ Ni ∼ Se and no potential health risk due to metal toxicity from average consumption. For sites that had high levels of Cd and Pb, bioaccumulation occurred from atmospheric deposition. Concentrations of elements in soil were found to be in decreasing order of Fe (1059–63747 mg kg−1) > Ca (1048–41475 mg kg−1) > Mg > Mn (9.76–174 mg kg−1) > Cr (1.55–135 mg kg−1) > Zn (0.76–58.2 mg kg−1) > Se > Cu > Ni > Pb > Co > As ∼ Cd with no evidence of heavy metal contamination. This study revealed that the plant inherently controlled uptake of essential elements according to physiological needs and that the concentrations of essential elements in the fruit could contribute positively to the diet. [ABSTRACT FROM AUTHOR]

Management of kidney stones primarily depends on various factors such as the presence of urinary tract obstruction, pain, stone size, location, impact on renal function, and the existence of infection. Renal colic is the classic presentation of an obstructive kidney stone. However, in this study, we present a cohort of non-verbal non-ambulatory (NVNA) patients who exhibit a distinct and uncommon presentation of kidney stones due to their medical conditions. Information about kidney stone disease in this gropup of complex pediatric patients is, scarce and their associated risk factors are not well understood. Therefore, we aim to summarize the clinical presentation, and management challenges in this unique group of NVNA patients to identify potential variables for prospective studies. A retrospective chart review was completed for all NVNA patients seen at the pediatric multidisciplinary kidney stone clinic between July 2020 to August 2022. Demographic variables, clinical presentation data, metabolic evaluation, radiological imaging, and surgical management was included for analysis. A total of 224 pediatric patients were referred to the multidisciplinary stone clinic. Of those, 27 were identified to be NVNA. The most common primary diagnosis was Cerebral Palsy followed by Lennox-Gastaut syndrome. Average age at first kidney stone presentation was 11.5 years ± 5.7 years. An obstructing stone was diagnosed in 18 (66%) patients, 4 (22.2%) of these presented with sepsis. Average stone burden was 9.2 mm (± 5.8 mm). Of the obstructing stones, 13 (72%) were in the kidney. All patients with an obstructing stone underwent surgical management with retrograde endoscopic approach. Metabolic 24-h-urine analysis was completed in 24 (89%) patients. 17 (62%) had an elevated urine density, 15 (55%) demonstrated calcium oxalate supersaturation, 12 (44%) met criteria for acidosis, and 7 (26%) had significant hypocitraturia. NVNA patients represent a unique cohort whose clinical presentation is atypical. Limited ability to express symptoms makes early detection difficult to recognize. Twenty two percent of patients present with sepsis as their first manifestation of an acutely obstructing kidney stone. Pain is subjectively interpreted by caregivers and is an uncommon symptom. Our cohort demonstrates common risk factors for stones including propensity for chronic dehydration, slow urinary tract transit, ineffective bladder emptying, G-tube feeding, and lithogenic medications. NVNA pediatric patients have atypical kidney stone clinical presentation. Awareness of this unique group of patients should support future collaborative studies to focus on understanding these atypical presentations and reflect on improving management. [Display omitted] [ABSTRACT FROM AUTHOR]

Distributions of dissolved rare earth element (REE) concentrations and neodymium isotopic compositions (expressed as εNd) of seawater over and off the Kerguelen Plateau in the Southern Ocean are presented. The sampling took place during the austral spring bloom in October–November 2011 (KEOPS2 project, GEOTRACES process study) and aimed to further the investigations of the KEOPS1 austral summer study in terms of sources and transport of lithogenic material, and to investigate the impact of local biogeochemical cycles on the REE distributions. The REE signature of the coastal eastern Kerguelen Islands waters was characterized by negative europium anomalies (Eu/Eu*) and negative εNd in filtered samples. By contrast, the unfiltered sample showed a positive Eu/Eu* and more radiogenic εNd. These distinct signatures could reflect either differential dissolution of the local flood basalt minerals or differential leaching of local trachyte veins. The dissolved Kerguelen coastal REE patterns differ from those observed close to Heard Island, these latter featuring a positive Eu/Eu* and a less radiogenic εNd (Zhang et al., 2008). These differences enabled us to trace the transport of waters (tagged by the Kerguelen REE signature) 200 km downstream from the coastal area, north of the Polar Front. Northward transport of the central Plateau shallow waters, enriched by both local vertical supplies and lateral advection of inputs from Heard Island, was also evident. However, the transport of Kerguelen inputs southeastward across the Polar Front could not be discerned (possibly as a result of rapid dilution or scavenging of REE signatures), although evidence for such transport was found previously using Ra isotopes (Sanial et al., 2015). Comparison of the REE patterns at stations sampled prior, during and at the demise of the bloom revealed diverse fractionations, including production of significant lanthanum and europium anomalies, which are tentatively ascribed to chemical reactions with various inorganic and biogenic phases, including surface coatings, barite crystals, and biogenic silica.

Lake Limboto is one of the major lakes in Sulawesi, Indonesia. It is currently undergoing serious degradation due to population pressure. As more residential areas have been established around the lake, the sedimentation rate has increased because of the contribution of anthropogenic particles. In this study, the lithogenic and anthropogenic components in surface sediments from 17 points in the lake were studied and identified using a combination of magnetic and geochemical analyses. The results showed that although the magnetic susceptibility values in R (residential) and NR (non-residential) areas were relatively similar, the values of saturation isothermal remanent magnetization (SIRM) as well as those of SIRM/χLF differed significantly, implying that the magnetic characteristics of the lithogenic component (in the NR area) differ from those of the anthropogenic component (in the R area). The discrepancy between the anthropogenic and lithogenic contributions was further supported by trace metals and rare earth element (REE) contents. Sediment samples in the R area contained higher levels of Mn, La, Pr, and Gd, while in the NR area they contained higher levels of Fe, Sc, Nd, and Ce. The magnetic susceptibility also correlated strongly with Fe, Cu, Zn, and Mn contents in the NR area. A similar correlation was not observed in the R area. The results above imply that a combination of magnetic and geochemical analyses can successfully differentiate lithogenic and anthropogenic components or contributions in lake sediments.

Mineral limitation of mesozooplankton production is possible in waters with low trace metal availability. As a step toward estimating mesozooplankton Fe and Zn requirements under such conditions, we measured tissue concentrations of major and trace nutrient elements within size-fractioned zooplankton samples collected in and around the Costa Rica Upwelling Dome, a region where phytoplankton growth may be co-limited by Zn and Fe. The geometric mean C, N, P contents were 27, 5.6 and 0.21 mmol gdw-1, respectively. The values for Fe and Zn were 1230 and 498 nmol gdw-1, respectively, which are low compared with previous measurements. Migrant zooplankton caused C and P contents of the 2-5 mm fraction to increase at night relative to the day while the Fe and Zn contents decreased. Fe content increased with size while Zn content decreased with size. Fe content was strongly correlated to concentrations of two lithogenic tracers, Al and Ti. We estimate minimum Fe:C ratios in large migrant and resident mixed layer zooplankton to be 15 and 60 μmol mol-1, respectively. The ratio of Zn:C ranged from 11 μmol mol-1 for the 0.2-0.5 mm size fraction to 33 μmol mol-1 for the 2-5 mm size fraction. [ABSTRACT FROM AUTHOR]

To assess the extent of soil contamination with a potentially toxic element, it is important to determine the background concentration of that element in the soil. In this study we decided to investigate the relationship between trace element concentrations in soils and the lithology of their parent rocks. We collected 85 topsoils (0–20 cm) samples from the Petorca, La Ligua, Aconcagua, and Casablanca River basins (Valparaiso region, central Chile). For soil sampling, we chose 11 tributary watersheds free of anthropogenic influence. The areas that contributed to the formation of each alluvial soil were delineated and the parent lithologies were acquired from 1:250,000 geological maps. The results show that the total concentrations of arsenic (As), copper (Cu), lead (Pb), and zinc (Zn) in soil vary considerably among the four river basins studied. Soil concentrations of all elements under study are positively correlated with the presence of andesitic volcanic rocks. Furthermore, soils formed from marine sediments and felsic volcanic rocks had the highest concentrations of Pb and As. The carbonate-bearing marine sediments may have adsorbed As and Pb released by weathering of felsic volcanic rocks found upstream of the study area. In contrast, lithologies dominated by continental sedimentary and plutonic rocks showed negative correlations with the concentrations of As, Cu, Pb, and Zn in the soil. Thus, the differences in soil element concentrations in the watersheds under study were due to the different rock types present in the area. We argue that absolute "one-limit-fits-all" background trace element values may be inadequate to assess the extent of soil contamination. Therefore, it is important to determine background concentrations of soil elements in each river basin in the anthropogenically impacted areas. In contrast, erroneous conclusions can be drawn when background concentrations are determined in one region and then applied in another region that is lithologically different. • Rock lithology affected background element concentrations in the studied soils. • Cu and Zn concentrations correlated positively with andesitic volcanic rocks. • Carbonate-bearing oceanic sediments adsorbed Pb and As released by volcanic rocks. • It is important to establish background concentrations for each river basin. • An absolute "one-limit-fits-all" total metal concentration may be inadequate. [ABSTRACT FROM AUTHOR]

In this paper, we present, describe, and model the first size-fractionated (0.8–51 µm; >51 µm) water-column particulate trace metal results from the US GEOTRACES North Atlantic Zonal Transect in situ pumping survey, with a focus on the lithogenic tracer elements Al, Fe and Ti. This examination of basin-wide, full-depth distributions of particulate elements elucidates many inputs and processes—some for bulk lithogenic material, others element-specific—which are presented via concentration distributions, elemental ratios, size-fractionation dynamics, and steady-state inventories. Key lithogenic inputs from African dust, North American boundary interactions, the Mediterranean outflow, hydrothermal systems, and benthic nepheloid layers are described. Using the refractory lithogenic tracer Ti, we develop a 1-D model for lithogenic particle distributions and test the sensitivities of size-fractionated open-ocean particulate Ti profiles to biotically driven aggregation, disaggregation rates, vertical sinking speeds, and dust input rates. We discuss applications of this lithogenic model to particle cycling in general, and to POC cycling specifically. [ABSTRACT FROM AUTHOR]

More than 200 sediment trap samples were collected at 310 or 360m depth during 2002-2009 from the center of the 410m-deep Alfonso Basin in La Paz Bay, an arid, subtropical embayment of the southern Gulf of California. Sample splits were analyzed for total mass flux (TMF), particulate organic carbon (POC), inorganic carbon (CaCO3) and opal (biogenic silica BioSi). The lithogenic (Litho) and biogenic fluxes (Biogen), but especially the particulate organic matter (POM) and CaCO3, fluxes are relatively high compared with those recorded in a number of other coastal basins at depths less than ~500m. The average yearly Litho fluxes (mean of 133±158gm−2yr−1) are well correlated with the frequency of strong wind gusts and reflect the relative proximity of the mooring to shore and the importance of eolian transport. The sedimentation patterns are influenced by monsoonal shifts--cool temperatures and strong northerly winds in late fall and winter sustain a well-mixed deep surface layer and high lithogenic fluxes, whereas progressive heating and relatively weak southerlies in summer and fall lead to a shallower, more-stratified surface layer with lower nutrient levels, limited productivity and generally low particulate fluxes. There is considerable interannual variability in the size of the various fluxes. This is likely related to a number of regional and internal factors whose timing, intensity and interactions remain to be resolved. Although there is an inverse relationship between SST and satellite-derived net primary production (NPP) estimates, no correlation was found between NPP and the POC, CaCO3 and BioSi fluxes (r2<0.05 and p>0.05). Significant correlations (p<0.001) do exist, however, between the POC flux and the total mineral flux as well as with the CaCO3, Litho and BioSi fluxes (r=0.86, 0.82, 0.79 and 0.69, respectively). As suggested by the ballast ratio hypothesis, the strength of these correlations follows the relative density of the individual ballast components. Among the ballast minerals, the Litho fraction correlates strongly with CaCO3 (r=0.84), both fluxes being important during the windy cool season. The lithogenic fraction accounts for almost half of the total mass flux and is clearly a significant ballasting agent in this continental margin basin. [ABSTRACT FROM AUTHOR]

Soils from cocoa plantations treated with Boudreaux mixture in two southwestern states of Nigeria were collected at different depths, 0–15 cm and 15–30 cm, and subjected to five-stage sequential extraction to obtain the speciation forms of copper: exchangeable, carbonate, manganese and iron oxides, organic and residual fractions. The Cu content in the extracts from the sequential extraction was read with an Atomic Absorption Spectrophotometer (AAS). The total Cu content of the soil and the physicochemical parameters of the soils were also determined. The results from the study showed that the soils had high organic matter and copper is mostly bounded to the more mobile exogenic phase much more than the stable lithogenic phase, indicating higher mobility. Within the exogenic species, carbonate fraction was the highest followed by the organic bound and the exchangeable fraction in decreasing order. Cu was not detected in the Fe/Mn bound fraction. The implication is that the fate of the administered Cu-based pesticide is more in the relatively stable carbonate bound species than the other, more mobile phase. The results showed variation in the distribution of the copper species from one depth to another. The most transported metal from the surface to the lower layer is the exchangeable fraction. The carbonate bound species is less mobile and is not readily transported into the bottom soil layer. The organic bound Cu has nearly equal distribution between the top and bottom soils and there was little or no transport of the residual metal specie from the top to the bottom. The existence of copper in the soil largely in the anthropogenic (exogenous) phase is not the most desirable for the ecosystem. This may increase the availability of Cu in the cocoa plant and bean and may lead to potential exposure risk. [ABSTRACT FROM PUBLISHER]

Heavy metals’ origin, accumulation, and distribution in soil have been the focus of much attention by many researchers. The objective of this study was to recognize the sources of heavy metals in surface soils in Hamadan Province in western Iran using multivariate geostatistical techniques. A total of 263 surface (0–10 cm) soil samples and 18 rock samples from major parent materials were collected. Cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) contents of the samples were determined. Selected soil physical and chemical characteristics were also measured. A multivariate geostatistical analysis was performed to identify the common source of heavy metals. The quantities of Co, Cr, and Ni were found to be associated with parent rocks, corresponding to the first factor termed the “lithologic component.” The second factor was mainly attributed to Cu, which also comprised the first and third factors, indicating a mixed source both from lithologic and anthropogenic inputs. Zn and Pb contents were related to the anthropogenic activities and comprised the third factor. A significant correlation was found between metals from the lithogenic sources and selected soil properties such as soil organic matter, clay, CEC, and carbonate, indicating an interaction among them. Generally, Zn and Pb showed a less significant correlation with soil properties. [ABSTRACT FROM AUTHOR]

The vertical distribution of mercury along a weathering profile derived from a diabase was compared to the main geochemical and mineralogical characteristics of the soil and its parental rock. The sampling site was in a metropolitan area, nearby to an active quarry and relatively close to an industrial park. The samples of a 6-m-deep fresh exposure of the soil profile and also of fresh rock were collected during the dry season. Kaolinite, goethite, hematite, and residual primary minerals were identified in the soil samples. Typically, the concentrations of Hg in the soil are low. Whole samples contained between 1 (rock) and 37 μg kg Hg, while the < 63-μm soil fraction had up to 52 μg kg Hg. The higher values of Hg corresponded to the upper layers of A (0-10 cm) and B (200-220 cm) soil horizons. Elemental gains and losses calculated against Zr resulted in the following order: Hg>>Pb > Zr > LREE > Nb > HREE > Al > Ti > Fe > Cr. Total organic carbon in soil samples varied between 0.2 and 5.1 g dm, and correlation with Hg concentrations was moderate. The acid pH (4.2-5.5) of the soil samples favors the sorption Hg species by predominant secondary phases like goethite and kaolinite. The Hg concentration of the rock is insufficient to explain the large enrichment of Hg along the soil profile, indicating that exogenic Hg, via atmospheric deposition, contributed to the measured Hg concentrations of the soil. [ABSTRACT FROM AUTHOR]

Abstract: We analyzed the chemical composition of suspended matter from the Black Sea for a complete suite of elements used as tracers for various sources and processes. Samples of suspended matter were collected at four stations from the Bosporus to the center of the western gyre during a R/V Bilim cruise in September 2000. Sample depths were from the oxic surface layer, the suboxic zone and the upper part of the anoxic (sulfidic) layer. All samples were analyzed for Al, Ti, V, Cr, Mn, Fe, Co, Cu, Zn, Mo, Ag, Cd, Ba, Pb, U and P using ICP-MS, AAS, and spectrophotometer. The main objective of this study was to determine the processes that influence the distributions of particulate trace metals in the water column under various redox environments. The composition of the particulate matter was influenced by lithogenic input from surrounding rivers, biological production in the surface layer, biogeochemical (e.g. redox) processes and anthropogenic inputs. Almost all elemental concentrations decreased from the coastal to the offshore stations to the center of the western gyre. Metal/Al ratios were compared with the ratios of average crust and Danube and Turkish rivers. Deviations from these lithogenic sources were used to examine the anomalies due to geochemical, biological and anthropogenic processes. In general, the largest metal enrichments relative to crust were observed inthe surface samples away from coastal sources. Metal/P ratios were used to compare data for some of the elements with previous data from the open ocean. The Me/P ratios for Cu, Zn, Mo and Ni were much higher than open ocean studies, while the ratios for Cd and Co were comparable. The high Me/P (and Me/Al) for several elements suggest anthropogenic input may contribute to these high surface concentrations. The composition of particulate matter from the suboxic zone showed that some elements were strongly enriched. Enrichments of Mn and Fe in the suboxic zone were observed, as expected. Mn and Fe oxides play an important role in scavenging processes. The redox dependent processes in the suboxic - anoxic interface influence the vertical distribution of U, V, Ni, Co, Cu, Zn, Ba and possibly Mo, Cr. Elements influenced by sulfide formation in the anoxic layer were Fe, Cr, Ni, Co, Mo, and Ag. [Copyright &y& Elsevier]

Partial extraction was carried out on thirty-three (33) soil samples collected from the Bassa industrial zone 1 of Douala, Cameroon. From the samples analyzed the following metal concentrations (range) were obtained (in ppm): Ag (0-1.3), As (0-64), Cd (0-7.3), Co (0-31), Cr (34-423), Cu (12-909), Mn (55- 3282), Mo (0-81.6), Ni (9-284), Pb (0-3320), Sb (0-30), Sc (0.6-7.5), V (26- 110), Zn (30-3782), and Fe (in wt %) (1.50-47.31). Results obtained reveal background and anomalous populations for most of the metals except Sc and V, which only have background populations. Multi-element geochemical anomalies occur within the vicinity of industries, waste dump sites, metal workshops, and mechanical workshops. R-mode factor analysis reveals three element associations and two singular elements (As, Cd) accounting for 94% of the total data variance. The three associations are: Ag-Cu-Cr-Fe-Mn-Mo-Ni-Sb; Co-Cu-Pb-Sb-Zn; and Sc-V. The geoaccumulation indices show that soils in the Bassa industrial zone are moderately to very highly polluted. These metal-laden soils constitute a major health risk to the local population and a cause for concern. This study successfully relates the concentration and distribution of toxic metals in the soils of the Bassa industrial zone to urban effluents generated mainly from industrial activities. [ABSTRACT FROM AUTHOR]

Recently, we demonstrated that cholesterol gallstone-prone C57L/J mice rarely develop gallstones unless they are infected with certain cholelithogenic enterohepatic Helicobacter species. Because the common gastric pathogen H. pylori has been identified in the hepatobiliary tree of cholesterol gallstone patients, we wanted to ascertain if H. pylori is cholelithogenic, by prospectively studying C57L infected mice fed a lithogenic diet. Weanling, Helicobacter spp.-free male C57L mice were either infected with H. pylori SSI or sham dosed. Mice were then fed a lithogenic diet (1.0% cholesterol, 0.5% cholic acid, and 15% dairy triglycerides) for 8 wk. At 16 wk of age, mice were euthanatized, the biliary phenotype was analyzed microscopically, and tissues were analyzed histopathologically. H. pylori infection did not promote cholesterol monohydrate crystal formation (20% vs. 10%), sandy stone formation (0% for both), or true gallstone formation (20%) compared with uninfected mice fed the lithogenic diet (10%). Additionally, H. pylori failed to stimulate mucin gel accumulation in the gallbladder or alter gallbladder size compared with uninfected animals. H. pylori-infected C57L mice developed moderate to severe gastritis by 12 wk, and the lithogenic diet itself produced lesions in the forestomach, which were exacerbated by the infection. We conclude that H. pylori infection does not play any role in murine cholesterol gallstone formation. Nonetheless, the C57L mouse develops severe lesions of both the glandular and nonglandular stomach in response to H. pylori infection and the lithogenic diet, respectively. [ABSTRACT FROM AUTHOR]

Lake Limboto is one of the major lakes in Sulawesi, Indonesia. It is currently undergoing serious degradation due to population pressure. As more residential areas have been established around the lake, the sedimentation rate has increased because of the contribution of anthropogenic particles. In this study, the lithogenic and anthropogenic components in surface sediments from 17 points in the lake were studied and identified using a combination of magnetic and geochemical analyses. The results showed that although the magnetic susceptibility values in R (residential) and NR (non-residential) areas were relatively similar, the values of saturation isothermal remanent magnetization (SIRM) as well as those of SIRM/χLF differed significantly, implying that the magnetic characteristics of the lithogenic component (in the NR area) differ from those of the anthropogenic component (in the R area). The discrepancy between the anthropogenic and lithogenic contributions was further supported by trace metals and rare earth element (REE) contents. Sediment samples in the R area contained higher levels of Mn, La, Pr, and Gd, while in the NR area they contained higher levels of Fe, Sc, Nd, and Ce. The magnetic susceptibility also correlated strongly with Fe, Cu, Zn, and Mn contents in the NR area. A similar correlation was not observed in the R area. The results above imply that a combination of magnetic and geochemical analyses can successfully differentiate lithogenic and anthropogenic components or contributions in lake sediments. [ABSTRACT FROM AUTHOR]