Cobalt Content Research Articles

Prenatal Parental Exposure to Metals and Birth Defects: A Prospective Birth Cohort Study.

While maternal exposure to high metal levels during pregnancy is an established risk factor for birth defects, the role of paternal exposure remains largely unknown. We aimed to assess the associations of prenatal paternal and maternal metal exposure and parental coexposure with birth defects in singletons. This study conducted within the Jiangsu Birth Cohort recruited couples in early pregnancy. We measured their urinary concentrations for 25 metals. A total of 1675 parent-offspring trios were included. The prevalence of any birth defects among infants by one year of age was 7.82%. Paternal-specific gravity-corrected urinary concentrations of titanium, vanadium, chromium, manganese, cobalt, nickel, copper, and selenium and maternal vanadium, chromium, nickel, copper, selenium, and antimony were associated with a 21-91% increased risk of birth defects after adjusting for covariates. These effects persisted after mutual adjustment for the spouse's exposure. Notably, when assessing the parental mixture effect by Bayesian kernel machine regression, paternal and maternal chromium exposure ranked the highest in relative importance. Parental coexposure to metal mixture showed a pronounced joint effect on the risk of overall birth defects, as well as for some specific subtypes. Our findings suggested a couple-based prevention strategy for metal exposure to reduce birth defects in offspring.

Mineral and Organic Materials as Factors Reducing the Effect of Petrol on Heavy Metal Content in Soil.

As industrial production increases worldwide, so does the demand for fuels. The transport of fuels from the point of production to the end user poses a risk of environmental pollution, both during transport and during combustion in internal combustion engines. The soil is a part of the environment which is particularly sensitive to contamination by petroleum substances. For this reason, research has been carried out into the possibility of reducing the impact of petrol on the content of heavy metals in the soil using various materials, both mineral (bentonite, calcium oxide) and organic (compost). These played an important role in the in situ remediation of contaminated soils. Petrol contamination increased the content of some heavy metals (Pb, Cd, or Ni), while it decreased the content of other metals (Cr, Zn, Co, and Cu) in the soil. The materials used in this study significantly altered the levels of heavy metals in the soil. The strength of the effect varied and the direction of the effect depended on the element. Bentonite was the most effective, while calcium oxide and especially compost were less effective. The most beneficial (limiting) effect of calcium oxide was shown on the soil content of cadmium, cobalt, and chromium, while the bentonite effects were on the content of chromium. The application of the abovementioned materials seems to be effective in reducing low level soil contamination by petrol.

Accumulation of heavy metals and arsenic in plants in the vicinity of the Chadan coal deposit (Republic of Tuva)

The content of copper, zinc, lead, cadmium and cobalt in plant samples from the vicinity of the Severny dump of the Chadansky coal mine in the Republic of Tuva was studied. Heavy metals in plant samples were determined by the Quantum-2mt atomic absorption spectrophotometer. Due to the extra-arid conditions, the studied area belongs to the zone of risky agriculture and there is developed cattle breeding. It was revealed that vegetation typical for steppe communities is developed on the territory of the Chadan coal deposit, represented by wormwood-cereal, grass-grass-wormwood, grass-wormwood-kovyl, wormwood-grass-grass steppes. In the dumps, deposits of different ages with small-scale, wormwood-cereal communities with typically steppe species are developed. For lead, cadmium and cobalt, the concentrations in vegetation samples from the CER and SWZ sites adjacent to the dump turned out to be close to their background values. The Cu content in the vegetation of the dump sites exceeds the natural content by 2–2,2 times, Zn – 2–2,7 times, Pb – 1,5 times. However, a comparison of the content of Cu, Cd, Zn, Pb, Co in vegetation from 2 sites of the Severny dump and the background territory with MDU for plant feeds showed that their concentrations in the studied samples are much lower than the maximum permissible level.

Influence of cobalt doping on structural, optical, and electrical properties of zinc oxide nanoparticles prepared by polymeric precursor method

Cobalt-doped ZnO nanoparticles at different compositions have been obtained by the polymeric precursor method. The nanoparticles were obtained at the working pH from 8.3 to 8.5 and synthesized at 550 °C. The properties were studied using X-ray diffraction (XRD), vibrational spectroscopy (FTIR/Raman), diffuse reflectance absorbance spectroscopy (DR UV–Vis), photoluminescence spectroscopy (PL), scanning electron microscopy (SEM/EDS), and impedance spectroscopy. The lattice parameters were determined at room temperature by Rietveld refinement, confirming single-phase composition with a hexagonal wurtzite structure. FTIR and Raman analyzes identified the characteristic vibrations of the synthesized system and the typical deformations of the wurtzite-type hexagonal structure, corroborating the results obtained from XRD. A redshift in the optical energy band gap (Egopt) was observed with increasing cobalt content compared to the ZnO sample. Considering the doping percentage, Egopt value varied between 3.13 eV and 3.04 eV for pure ZnO and Co-doped ZnO with 5 at. %., indicating that the optical properties of the nanoparticles were affected by dopant concentration. PL and SEM/EDS characterization were used to determine the associated defects for each sample and the morphology and composition of the nanoparticles. PL results showed a strong blue emission at around 439 nm (2.83 eV), which is redshift with cobalt content (ΔE between 0.05 eV and 0.01 eV), attributed to the surface defects present in the doped samples. Conductivity analysis to temperature revealed a semiconductor behavior for all samples, and their respective activation energies determined. The results provide an easy method to obtain Co-doped ZnO nanoparticles with interesting properties for optoelectronics devices.

Injectable hydrogel scaffold incorporating microspheres containing cobalt-doped bioactive glass for bone healing.

Injectable in situ-forming scaffolds that induce both angiogenesis and osteogenesis have been proven to be promising for bone healing applications. Here, we report the synthesis of an injectable hydrogel containing cobalt-doped bioactive glass (BG)-loaded microspheres. Silk fibroin (SF)/gelatin microspheres containing BG particles were fabricated through microfluidics. The microspheres were mixed in an injectable alginate solution, which formed an in situ hydrogel by adding CaCl2. The hydrogel was evaluated for its physicochemical properties, in vitro interactions with osteoblast-like and endothelial cells, and bone healing potential in a rat model of calvarial defect. The microspheres were well-dispersed in the hydrogel and formed pores of >100 μm. The hydrogel displayed shear-thinning behavior and modulated the cobalt release so that the optimal cobalt concentration for angiogenic stimulation, cell proliferation, and deposition of mineralized matrix was only achieved by the scaffold that contained BG doped with 5% wt/wt cobalt (A-S-G5Co). In the scaffold containing higher cobalt content, a reduced biomimetic mineralization on the surface was observed. The gene expression study indicated an upregulation of the osteogenic genes of COL1A1, ALPL, OCN, and RUNX2 and angiogenic genes of HIF1A and VEGF at different time points in the cells cultured with the A-S-G5Co. Finally, the in vivo study demonstrated that A-S-G5Co significantly promoted both angiogenesis and osteogenesis and improved bone healing after 12 weeks of follow-up. These results show that incorporation of SF/gelatin microspheres containing cobalt-doped BG in an injectable in situ-forming scaffold can effectively enhance its bone healing potential through promotion of angiogenesis and osteogenesis.

Study Plant Contamination Surrounding the Brick Factory in Al- Saniyah: Al- Diwaniyah Governorate, Iraq

This study examined how brick factories in Al-Saniyah, Al-Diwaniyah Governorate, affected the surrounding plants at 50, 500, and 1000-meter intervals in relation to the direction of the prevailing winds, as well as at 50, 500, and 1000-meter intervals in the opposite direction. Zinc concentrations were measured; the values ranged from 20.2 µg\g in the summer to 161.3 µg\g in the winter. Additionally, in winter, the content of cadmium was 0.39 at its lowest and 3.7µg\g at its maximum. The maximum concentration of cobalt was 41.55 µg/g in winter, while the lowest was 2.55 µg/g in summer. While the highest value in Pb was 96.4 µg/g in S2 in winter and the lowest value was 0.7 µg/g in S6. It's possible that the causes Seasonal variations in wind and precipitation that leave suspended metals in the atmosphere may be the cause of wintertime increases in element concentrations. Alternatively, better weather could be the reason for a rise in productivity.

An inclusive study to elucidation the heavy metals-derived ecological risk nexus with antibiotic resistome functional shape of niche microbial community and their carbon substrate utilization ability in serpentine soil

Heavy metals (HMs) contained terrestrial ecosystems are often significantly display the antibiotic resistome in the pristine area due to increasing pressure from anthropogenic activity, is complex and emerging research interest. This study investigated that impact of chromium (Cr), nickel (Ni), cobalt (Co) concentrations in serpentine soil on the induction of antibiotic resistance genes and antimicrobial resistance within the native bacterial community as well as demonstrated their metabolic fingerprint. The full-length 16S-rRNA amplicon sequencing observed an increased abundance of Firmicutes, Actinobacteriota, and Acidobacteriota in serpentine soil. The microbial community in serpentine soil displayed varying preferences for different carbon sources, with some, such as carbohydrates and carboxylic acids, being consistently favored. Notably, 27 potential antibiotic resistance opportunistic bacterial genera have been identified in different serpentine soils. Among these, Lapillicoccus, Rubrobacter, Lacibacter, Chloroplast, Nitrospira, Rokubacteriales, Acinetobacter, Pseudomonas were significantly enriched in high and medium HMs concentrated serpentine soil samples. Functional profiling results illustrated that vancomycin resistance pathways were prevalent across all groups. Additionally, beta-lactamase, aminoglycoside, tetracycline, and vancomycin resistance involving specific bio-maker genes (ampC, penP, OXA, aacA, strB, hyg, aph, tet(A/B), otr(C), tet(M/O/Q), van(A/B/D), and vanJ) were the most abundant and enriched in the HMs-contaminated serpentine soil. Overall, this study highlighted that heavy-metal enriched serpentine soil is potential to support the proliferation of bacterial antibiotic resistance in native microbiome, and might able to spread antibiotic resistance to surrounding environment.

Cobalt enrichment and metallogenic mechanism of the Galinge skarn iron deposit in the Eastern Kunlun metallogenic belt, western China

Skarn iron deposits, as representative examples of Co-rich magmatic-hydrothermal deposits, are attracting increasing attention due to rising cobalt demand worldwide. However, the specific Co enrichment mechanisms and metallogenic processes in skarn deposits remain elusive. This study presents high-precision in situ U–Pb geochronological data for garnet from skarns, major and trace element analyses of sulfarsenides and sulfides, and X-ray mapping in the Galinge deposit. The Galinge skarn iron deposit formed at 237.1 ± 0.3 Ma (garnet U–Pb dating), during which time the region was in the post-collisional stage. During this period, the crust was thickened, causing delamination of the lithospheric mantle, which further led to the upwelling of asthenospheric materials and partial melting of the lower crust. As the resultant mixed magma ascended, it reacted with carbonate strata to form skarn deposits. Cobalt shows two occurrence modes in the Galinge deposit: independent cobalt minerals such as skutterudite and cobaltite, and isomorphic substitution of Co with other metals in ore minerals (arsenopyrite, pyrrhotite, sphalerite, pyrite, magnetite, and chalcopyrite). Our results revealed that arsenopyrite is the most cobalt-enriched ore mineral in the Galinge deposit, with an average Co content of 34,077 ppm. Other minerals generally contain insignificant Co contents of less than 500 ppm, including sphalerite (471 ppm) > pyrite (194 ppm) > pyrrhotite (145 ppm) > alabandite (∼100 ppm) > magnetite (7 ppm) > chalcopyrite (2 ppm). In arsenopyrite, cobalt and nickel replace iron in accordance with the inverse correlation between the concentrations of cobalt and nickel (wt%) and that of iron. In pyrite and chalcopyrite, a portion of the isomorphic cobalt substitutes for Fe or Cu. The weak correlation between Co (ppm) and Cu or Fe (wt%) indicates that only isomorphic cobalt is carried out by substituting Fe or Cu. The negative correlation between Co + Fe and Zn or Mn suggests that cobalt and iron replace Zn or Mn in sphalerite and alabandite. No evidence of element substitution was observed in pyrrhotite. Our study highlights that during the early mineralization stage, cobalt in the magmatic-hydrothermal fluids migrated in the form of CoCl42-. Subsequently, under the influence of an increase in pH, CoCl42- reacts with H3AsO30 to form CoAs3 (skutterudite). With the continuous precipitation of arsenides and sulfarsenides, the As/S (reduced) ratio decreased, leading to the CoAs3 (skutterudite) changing to CoAsS (cobaltite).

Enhanced hydrogen separation performance of cobalt-doped microporous silica membranes: Influence of cobalt content and processing parameters

This research focused on synthesizing microporous silica and cobalt-doped silica through acid-catalyzed hydrolysis and condensation. The effects of various synthesis parameters (calcination temperature, cobalt content, and cobalt addition step) were investigated. The results confirmed that the presence of cobalt in the microporous structure enhances the performance of the silica membrane. However, the hydrothermal stability remained unchanged, which can be attributed to the pore size of the silica. The competitive cobalt-doped silica sol coated on a modified support, resulting in a membrane with better performance compared to the blank silica membrane. The membrane was subjected to single gas permeation tests: H2 permeance of 1.8 × 10−7 mol m−2 s−1 Pa−1 and H2/N2 selectivity of 58 at a low temperature of 200 °C. The high apparent activation energy (Ea) observed for H2, suggests the presence of a molecular sieving mechanism, which was further improved by incorporating cobalt into the microporous structure of silica.

Effect of grain size and cobalt content on machining performance during milling tungsten carbide with PCD tool

Tungsten carbide has been extensively utilized in the manufacturing field due to its exceptional properties. However, traditional methods such as grinding or electric discharge machining often result in a low material removal rate and inevitable surface defects, making tungsten carbide one of the most challenging materials to machine. Milling has emerged as a promising alternative for machining tungsten carbide. However, the milling of tungsten carbide has not been widely applied in the industry due to a lack of comprehensive understanding regarding the milling performance of different tungsten carbides under various conditions. In this paper, a polycrystalline diamond (PCD) tool was used in the milling of tungsten carbides to investigate the effects of tool grain size, workpiece Co content, and WC grain size on tool wear and machining surface quality. It was found that PCD tools with larger grain sizes exhibited higher wear resistance. Additionally, excessive Co content in the workpiece and large WC grain size increased tool wear and degraded the quality of the machined surface. The primary types of tool wear observed in the milling of WC-Co included adhesive wear, abrasive wear, phase change wear, and oxidation wear.

Effect of substituting manganese by few cobalt content in the transport properties of Pr/Ca based manganite

Effect of substituting manganese by few cobalt content in the transport properties of Pr/Ca based manganite

Seasonal Variation of Heavy Metals in the Bivalves of a Major Fish Landing Centre in Mumbai

One of the most prevalent environmental contaminants found in aquatic ecosystems and its associated biota is considered to be heavy metals. The current study evaluated the heavy metal concentrations of Copper (Cu), Iron (Fe), Cadmium (Cd), Zinc (Zn), Manganese (Mn), Cobalt (Co), Chromium (Cr), Arsenic (As), Nickel (Ni), and Lead (Pd) in the soft tissues of M.casta and Paphia malabarica species seasonally for one year. The soft tissue of the two species were digested using a microwave digestion system (CEM-MARS-5) using nitric acid and perchloric acid. Evaluation of Cu, Ni, Cr, Mn, Co, Fe, and Zn was done using ICP-OES while for estimation of Pd, Cd and As, ICP-MS was used. During the study, Fe, Mn and Zn content dominated the whole soft tissues of both species. The findings demonstrated that the pre-monsoon season had higher amounts of the most examined heavy metals, whereas the monsoon season had the lowest quantities of these metals in the soft tissues of both species.

Electrochemical applications of CdO-Co-ZnO nanocomposites, their synthesis and characterization reveal their multifunctional abilities

In this study, we investigated the electrochemical catalysis potential of hybrid nanocomposites containing CdO, Co and ZnO nanocomposites, as opposed to Zn-O doped Co nanocomposites, have weaker Coulomb interactions due their ionic bonds. Because CdO and Co form a covalent bond, Co interacts more strongly with O than Zn. In order to reduce nanoparticle crystallinity, oxygen defects improve the interaction between −O and oxygen defects in the lattice. From SEM micrographs, it appears that CdO does not completely change under the influence of dopants. It can be seen from the SEM image that both materials have very tightly packed particles. The Co and CdO dopants in ZnO nanocomposites prevent them from absorbing a large range of visible wavelengths. It is more energy-dense for nanocomposites with 5.28 eV to compare to 5.14 eV nanocomposites. The fact that CdO matrix has a tuneable bandgap is evident since different types of dopants are used in its manufacture. There are at least three distinct absorption modes in Co nanocomposites doped with CdO, around 450, 498, and 676 cm−1. In addition to its absorption from 450 cm−1 and 498 cm−1 vibrational modes, Co-O stretching absorption along the [101] plane has also been observed at 676 cm−1. As a method of studying charge carriers, photoluminescence spectroscopy is usually used. This method can be used to analyze electron-hole pairs (e−/h+) formed by semiconducting particles. It is in the blue emission range between the luminescence band of 615 nm and the valence band of 635 nm. With increasing cobalt and zinc concentrations, CdO nanomaterials lose their remanent magnetization. CdO has been demonstrated to have significant coercive effects in both pure and additively incorporated solutions regardless of their anisotropic, morphological, porosity, and particle size distribution. Electrochemical impedance spectrum measurements were conducted between 100 kHz and 0.01 Hz. According to the Nyquist plot, purity CdO, CdO doped Co, and CdO doped ZnO nanocomposites show a high frequency resistance to charge transfer. Nanocomposites that contained CdO doped Co & ZnO were exposed to UV light for 120 min to remove the solution. The degradation of MO is virtually nonexistent when no photocatalyst is present, but with a photocatalyst, degradation can reach 92.56 %.

PRODUCTION OF SYNTHETIC HYDROCARBONS USING COBALT CATALYSTS BASED ON ZSM-5 ZEOLITE

In this work, cobalt catalysts based on zeolite ZSM˗5 were prepared by the triple impregnation method and chemically analyzed. Zirconium dioxide was used as a promoter (3 wt. %). Chemical analysis of the elemental composition and structure of the obtained catalysts was carried out using scanning electron microscopy. It is shown that the elemental composition of the catalysts with satisfactory accuracy corresponds to their given composition. Experiments for catalytic tests of the prepared catalysts were carried out on a laboratory Fischer-Tropsch synthesis unit and synthetic hydrocarbons were obtained. Comparative characterization of activity of the obtained catalysts with cobalt content of 10 % and 20 % has been carried out, dependence of carbon monoxide conversion and selectivity with respect to formation of gas hydrocarbons and yield of liquid products on temperature has been studied.

Heavy Metals Contamination in Snow Cover of Pavlodar (Kazakhstan)

A study of the concentration of heavy metals in snow cover was carried out in Pavlodar in the area of influence of the Pavlodar Petrochemical Plant and other industrial facilities. Significant excesses of background concentrations of manganese, chromium, vanadium and other metals were detected. The distribution of metals in the snow cover showed that the elements have high values near the oil refinery and decrease at a distance of 700 m. The possible influence of other industrial enterprises and the direction of winds from CHP-3 are also noted. Manganese and barium show more stable values, and chromium, zinc, lead and cadmium have increased concentration near JSC “Kaustik”. The total concentration of manganese, strontium, cobalt and arsenic varies slightly across all sites, indicating uniform contamination by these substances. Lead is highest in industrial areas and in populated areas with highways. Aluminum and iron are widespread, with the lowest values in the Zhanaul village at a distance of 3 km from the Petrochemical Plant. The results of the study highlight the importance of controlling and monitoring heavy metal pollution and the need to take measures to reduce anthropogenic impacts on the natural environment.

Preparation of Bimetallic CoFe@CSC-700 Carbonated Microspheres and Activated Peroxymonosulfate for Degradation of Levofloxacin

The exploration of efficient, low-leaching, and recyclable transition-metal-based catalysts is of great importance for the removal of pollutants from peroxymonosulfate (PMS) in water purification processes. In this study, a bimetallic CoFe@CSC-700 composite was prepared by an alkaline gel pyrolysis reduction method using chitosan as a forming agent and applied to activate PMS to degrade levofloxacin (LEV). The leaching concentration of both cobalt and iron ions in the CoFe@CSC-700 catalyst was reduced by about 8-fold compared to the monometallic composite pellet catalyst. In addition, the removal efficiency of the CoFe@CSC-700 catalyst can still reach 90% after five cycles, showing good recyclability, recoverability and stability. Both free radical pathways (SO4·−, ·OH, and ·O2−) and non-free radical pathways (1O2) were detected in the oxidation reaction, with free radical pathways as the main contributor. The possible degradation pathways of LEV were proposed by LC-MS tests. Overall, this study provides new insights into the construction of efficient and stable PMS catalysts for wastewater treatment.

Effect of cobalt content on the microstructure, microtexture, and mechanical properties of W-Ni-Fe-xCo alloys during solid-phase-sintering and liquid-phase-sintering

Compared the effect of Co content on the microstructure, microtexture, and mechanical properties of W-Ni-Fe-xCo alloys during solid-phase-sintering and liquid-phase-sintering. The results indicated there is a non-uniform distribution of W and γ phases, accompanied by the presence of little voids during solid-phase-sintering at 1420 °C. Adding Co element enhances the wetting between the W and γ phases, and reduces the liquid-phase-sintering temperature, shrinking the size and quantity of pores. The W phase transforms into ball-shaped particles with completed liquid-phase-sintering at 1440 °C. With increased Co content, W grain size decreases, matrix fraction volume increases, and Cw-w continuity and dihedral angle decrease. The mechanical properties of the alloys improve with sintering temperature and Co content, the tensile strength and elongation reached 989 MPa and 13.7% due to the elimination of holes and the W content increased within γ phase. The relationship among W content in γ phase, strength, elongation, and microhardness with Co content were revealed. The solution strengthening effect increases, which drives the co-deformation of W and γ phases, thereby increasing the strength and elongation. The addition of Co element and the atomic diffusion at high temperature made the fibre microtexture more concentrated.

Cobalt(II) removal with dolomite: Use of radiotracer technique in aqueous solution

Industrial processes have the potential to release cobalt into the environment, and exposure to cobalt in quantities higher than specific amounts can have harmful impacts on living organisms. This study aimed to determine whether natural dolomite from the Thrace region of Türkiye could effectively remove Co(II) from aqueous solutions. Batch studies were conducted to examine the impact of various experimental factors, including adsorbent dosage, initial Co(II) concentration, contact time, solution pH, and temperature. The cobalt concentrations in aqueous solutions were determined by employing 60Co radionuclide as a radiotracer. Experimental results revealed that optimum adsorption conditions were obtained at a solid-liquid ratio of 20 g·L−1, initial Co(II) concentration of 128 mg·L−1, contact time of 120 min, and pH 6 with a maximum adsorption capacity of 2.32 mg⋅g−1. The pseudo-second-order kinetic and Redlich-Peterson isotherm models described the experimental data well. The adsorption process of Co(II) ions on the dolomite was spontaneous and exothermic. The results showed the potential use of dolomite to remove such a toxic metal ion from industrial wastewater.

Residential proximity to toxic metal-emitting industrial sites and toenail metal concentrations in a United States-wide prospective cohort

BackgroundIndustrial facilities across the United States (US) release millions of pounds of toxic chemicals, including metals. Exposure to toxic metals has been associated with adverse health outcomes, but there is limited evidence on the association between living near metal-releasing facilities and the body burden of emitted compounds. ObjectiveTo investigate the association between residential proximity to toxic metal-emitting industrial facilities and toenail metal concentrations and to evaluate whether associations differed by race. MethodsIn a sample of 1556 non-Hispanic Black (32.5%) and non-Hispanic White (67.5%) women from the Sister Study, we used the US Environmental Protection Agency Toxics Release Inventory to identify metal-emitting facilities within 3, 5, and 10 km of participants’ baseline residences. We measured toenail concentrations (μg/g) of arsenic, cadmium, cobalt, chromium, and lead. Using multivariable linear regression, we examined associations between residential proximity to and emissions from metal-emitting facilities and toenail metal concentrations, stratifying by race. We explored modification of race-stratified associations by neighborhood deprivation, using the Area Deprivation Index (ADI). ResultsBlack participants were more likely to reside within 3 km of chromium-releasing facilities and 5 and 10 km of all observed metal-emitting sites. Living near metal-releasing facilities was not associated with higher toenail metal concentrations overall. Among Black women, higher chromium emissions exposure was associated with higher toenail chromium levels (βTertile3vs.non-exposed = 2.36 μg/g, 95% CI = 0.63, 4.10). An association with lead was observed among Black women residing in the most deprived areas (≥75th ADI percentile: β = 3.08 μg/g, 95% CI = 1.46, 4.71). No associations were observed for White participants. ConclusionsDespite low exposure prevalence, our findings suggest that living near chromium- and lead-releasing facilities, especially at shorter distances, may be associated with higher corresponding toenail metal levels among Black women, particularly those residing in the most disadvantaged areas.

Exposure to iodine, essential and non-essential trace element through seaweed consumption in humans

Seaweed consumption has gained popularity due to its nutritional value and potential health benefits. However, concerns regarding the bioaccumulation of several trace elements highlight the need for comprehensive studies on exposure associated with seaweed consumption. To address this gap in knowledge, we carried out a feeding intervention study of three common edible seaweeds (Nori, Kombu, and Wakame) in 11 volunteers, aiming to elucidate the extent of both beneficial and harmful trace element exposure through seaweed consumption in humans. Concentrations of total arsenic, cobalt, copper, cadmium, iodine, molybdenum, selenium, and zinc were measured in urine samples before and following seaweed consumption. Elements concentrations were also measured in the seaweeds provided for the study. Descriptive analysis for each element were conducted and we used quantile g-computation approach to assess the association between the 8-element mixture and seaweed consumption. Differences in urine element concentrations and seaweed consumption were analyzed using generalized estimating equations (GEE). Urinary concentrations of iodine and total arsenic increased after seaweed consumption. When we analyze the 8-element mixture, the largest weight was observed for iodine after Kombu consumption while for total arsenic was observed after Wakame consumption. Similar results were observed when we compared the mean differences between the elements before and after seaweed consumption through the GEE. Seaweed consumption relates with increased urinary iodine and total arsenic concentrations, particularly after Kombu and Wakame consumption.