High Risk For Cd Research Articles

Distribution, speciation, and assessment of heavy metals in sediments from Wadi Asal, Red Sea, Egypt

Globally, the environmental contamination of stream sediments due to geogenic and anthropogenic sources is of growing concern. In this study, the heavy metals (Cd, Co, Cr, Cu, Ni, Pb, and Zn) in 22 superficial sediments in Wadi Asal, Red Sea, Egypt, were explored to assess sediment sources, the mobility of chemical species, and the degree of contamination in sediments. Therefore, the total heavy metal values in the fine fraction (< 63 μm), a five-step sequential extraction on selective samples, risk assessment, and principal component analysis (PCA) were applied. The mobility of heavy metals in Wadi Asal sediments, according to non-residual fraction percent, declines in the following order: Cd (90.9%) > Pb (85.2%) > Co (84.4%) > Cu (80.8%) > Zn (75.9%) > Ni (48.4%) > Cr (39.6%); indicating the high mobility of Cd, Zn, Pb, Cu, and Co. The mean metal contamination factor (CF) order is Cd (10.96) > Ni (3.91) > Cr (2.77) > Zn (2.18) > Pb (2.10) > Co (1.12) > Cu (0.70). The Geo-accumulation Index (Igeo) is decreased in the following order: Cd (2.19) > Ni (0.78) > Cr (0.55) > Zn (0.44) > Pb (0.42) > Co (0.22) > Cu (0.14). The risk assessment code (RAC) revealed very high to high risk for Cd, Co, and Pb. The results pointed out that the metals Cr, Co, Cu, and Ni are from geogenic sources, while Zn, Cd, and Pb are from anthropogenic sources due to Pb–Zn mining activities. Based on the threshold effect level (TEL), Cd, Cr, Ni, and Pb have adverse effects on living organisms. According to these findings, the area along Wadi Asal and the downstream regions on the beach are highly polluted and heavy metal monitoring in sediments and aquatic organisms is recommended.

Empirical and Mechanistic Modeling of Release Kinetics of Heavy Metals and Their Chemical Distribution in the Rhizosphere and Non-rhizosphere Soils Under Vegetable Cultivation.

Biochemical processes in the rhizosphere affect the availability and distribution of heavy metals (HMs) in various forms. Rhizosphere soil (RS) and non-rhizosphere soil (NRS) samples were collected from 10 fields under tarragon(Artemisia dracunculus L.) cultivation to investigate the release kinetics and distribution of HMs including cadmium (Cd), cobalt (Co), copper (Cu), iron (Fe), and zinc (Zn) in five fractions. The cumulative amounts of Cu and Fe released after 88h were in the following ranges, respectively: 1.31-2.76 and 3.24-6.35mgkg-1 in RS and 1.41-2.72 and 3.15-5.27mgkg-1 in NRS. The parabolic diffusion and pseudo-second-order equations provided the best fit to the release kinetics data of Cu and Fe, respectively. The cation exchange model (CEM) based on Gaines-Thomas selectivity coefficients implemented in the PHREEQC program could well simulate the release of Cu and Fe suggesting that cation exchange was the dominant mechanism in the release of Fe and Cu from soils by 0.01 MCaCl2. Cadmium was predominantly found in fraction F2, while other HMs were mainly present in fraction F5. According to the risk assessment code, there was a very high risk for Cd, a medium risk for Co and Cu, a very low risk for Fe, and a low risk for Zn. Correlation analysis showed that soil physicochemical properties were effective in the distribution and transformation of HMs. Significant positive correlations between five fractions indicated that different forms of HMs can potentially transform into each other.

Toxic elemental abundances in the sediment of the Jamuna River, Bangladesh: pollution status, sources, toxicity, and ecological risks assessment

ABSTRACT In this study, elemental abundances of As, Cd, Cr, Co, Cu, Pb, and Zn in the 30 composite sediment samples from Jamuna River, Bangladesh were measured by atomic absorption spectrophotometer to assess their contamination level, toxicity, and ecological risks in both summer and winter season. In the summer season, mean concentrations of As, Cd, Cr, Co, Cu, Pb, and Zn in sediment samples were 2.82, 1.13, 25.30, 8.63, 22.01, 4.58, and 68.82 mg/kg, respectively. In the winter season, mean concentrations of As, Cd, Cr, Co, Cu, Pb, and Zn were 3.83, 1.48, 43.22, 13.86, 35.63, 8.48, and 100.27 mg/kg, respectively. The mean concentrations of all elements were found lower than the sediment quality guidelines values of probable effect level (PEL), effect range medium (ERM), and toxic effect thresholds (TET) in both seasons. There was a significant variation in elemental concentrations between wet and dry seasons and also between upstream and downstream sites (P < 0.05). Principal component analysis showed Zn, Cr, and Pb; As and Cu; and Cd and Co might have originated from the same geogenic source. The pollution evaluation indices showed consistent outcomes of almost no pollution for As, Cr, Co, Cu, Pb, and Zn, but moderately to strongly polluted for Cd in all seasons. The contamination level of elements follows the decreasing order of Cd > Zn > Cu > As > Co > Cr > Pb for both seasons. The elemental toxicity in the sediments follows the order of Cd > Cr > Zn > As > Cu > Pb, with a very high risk for Cd while a minimal risk for other elements. The ecological threats of the toxic elements were found moderate to very high. Therefore, the findings of our study concluded that the ecological condition of the Jamuna River posed a considerable risk for human health and living organisms.

Evaluation of coastal sediments for heavy metal contamination, Yanbu area, Red Sea coast, Saudi Arabia

To evaluate the heavy metal contamination, ecological risk and possible sources at Saudi Yanbu coastline, 30 sediment samples were collected for Fe, Pb, Ni, As, Zn, Cu, Cr, Co, Al, Sb, Cd, and TOC analyses using ICP-MS. The potential ecological risk index (PERI), enrichment factor (EF), contamination factor (CF), potential contamination index (Cp), geoaccumulation index (Igeo), soil pollution index (SPI) were calculated and interpreted, and multivariate analyses were applied. The results indicated the following order for metal averages: Al (8573 μg/g) > Fe (5895 μg/g) > Mn (192 μg/g) > Zn (80.4 μg/g) > Cu (35.87 μg/g) > Cr (27.11 μg/g) > Ni (23.5 μg/g) > Co (8.29 μg/g) > Pb (7.72 μg/g) > As (6.83 μg/g) > Sb (0.50 μg/g) > Hg (0.33 μg/g) > Cd (0.30 μg/g). Average levels of As, Ni, Zn, Co, Cd, and Pb values were greater than those reported from many coastal sediments from the Red Sea, Gulf of Aqaba, Arabian Gulf and Mediterranean Sea, as well as the sediment quality guidelines. The results of potential ecological risk revealed very high risk for Cd, high risk for Hg, considerable risk for Cu, Sb, and As, moderate risk for Pb and Ni, and no to low risk for Zn and Cr. The moderately severe enriched HMs (Cd, Zn, Cu, Hg) and the moderate enriched ones (Pb, Co, As) were originated mostly from anthropogenic sources related to industrial, agricultural, urbanization and fishing activities. The no and minor enriched HMs (Fe, Al, Ni, Cr, Sb) were mostly related to lithogenic factors related to rock weathering and atmospheric inputs.

A223 THE GEM PROJECT: ASSOCIATIONS OF DIETARY PATTERNS WITH MICROBIOME AND FECAL CALPROTECTIN IN HEALTHY FIRST-DEGREE RELATIVES OF CROHN’S DISEASE PATIENTS

Abstract Background Crohn’s disease (CD) is thought to be due to an interaction between environmental factors and the gut microbiome that activates an immune response in genetically susceptible hosts. Epidemiologic studies suggest diet is an important variable in CD development; however, little is known about the mechanism by which diet contributes to pathogenesis. It has recently been shown that diet plays a substantial role in shaping microbiome composition (MC). We hypothesize that specific diet patterns are associated with differences in MC that may be related to CD risk. Aims To characterize associations between diet patterns with MC and fecal calprotectin (FC) in healthy first-degree relatives (FDR’s) of CD patients in the Genetic, Environmental, Microbial (GEM) Project. Methods A validated food frequency questionnaire (FFQ) was used to assess diet for North American FDR’s at recruitment. Each question was summarized as a score based on weekly consumption frequency. The Dirichlet method of unsupervised clustering was used to generate dominant diet clusters. Diet-microbiome associations were assessed using the two-part microbiome model. Stool microbiota at recruitment was characterized by 16s RNA sequencing of V4 region using MiSeq platform. Baseline FC was measured by BUHLMANN ELISA test. Results 2766 FDR’s had FFQ’s at recruitment; mean age 18.52 years, 53% female. The Dirichlet method identified 4 clusters, some of which resembled known diet patterns: Superbowl (mainly organ meats, non-red meat, beer, spirits), High Carbohydrate (HC), Mediterranean (MD) and Western (WD) diets. HC was associated with increased relative abundance of V. veillonella (P=2.68E-4). Both HC and MD were associated with decreased abundance of E. klebsiella (P=2.64E-5 and P=1.02E-5 respectively). WD was associated with decreased abundance of L. dorea (P=5.74E-5), a genus considered high risk for CD. A per question analysis demonstrated significant associations between several taxa and individual foods. Diet clusters were then correlated with FC, and a decrease in FC was observed with MD (estimate -16.96, P=0.012). There were no associations with FC in a per question analysis. Conclusions Dominant dietary patterns and certain individual foods are associated with specific gut MC. As well, MD is inversely associated with FC and therefore has potential use as an intervention for lowering inflammation. Understanding relationships between diet, MC and FC in individuals at high risk for CD would be beneficial in defining new dietary strategies in predictably modulating future risk of CD. Funding Agencies CCCHelmsley Charitable Trust

Assessment of trace metal contamination and bioavailability in an Environmental Protection Area: Guaxindiba estuarine system (Guanabara Bay, Rio de Janeiro Brazil)

Guaxindiba River, located inside an Environmental Protected Area (EPA) inside Guanabara Bay, was evaluated concerning trace metals and arsenic. A total of 7 sediment cores up to 80 cm were extracted along the river and in the channel that connects Guaxindiba and Caceribu rivers. No natural enrichment from bottom to top was observed, suggesting a constant mobilization of the sedimentary column along the Guaxindiba River. Results showed elevated concentrations of Zn (175.77-321.01 mg.kg−1) and Ni (27.71-108.39 mg.kg−1) surpassing the probable effect levels (PEL) reference values. Sediments were considered severely enriched in Ni (EF >10) and Cu (EF>5). No enrichment was observed for As. The evaluation of bioavailability through the Risk Assessment Code (RAC), however, revealed medium risk for Zn and Ni, which exhibited high concentrations, and low risk for sediments severely enriched in Cu. Despite exhibiting minor enrichment and low concentrations, under PEL, the RAC revealed high risk for Cd, for bioavailability. Overall, the Guaxindiba River proved to be contaminated by recent pollution, in spite of its localization inside an EPA.

Sequential extraction studies on the river Tisa sediments for the assessment of the metal pollution

The sequential extraction procedure was applied for partitioning of metals in river sediments collected along the course of the river Tisa (Serbia). Eight elements (Sb, Sn, As, Cd, Cu, Hg, Pb and Zn) from twenty-one sampling site were analyzed using the modified BCR sequential extraction procedure in combination with ICP-OES. The results of sequential extraction, statistical analyses and calculation of EF and lithogenic and anthro?pogenic ratio of metals are similar. In the river Tisa sediments Sn, Cd, Hg, Pb and Zn are of anthropogenic origin, while As, Cu and Sb are of lithogenic and anthropogenic origin. The sediments from the river Tisa show high risk for Cd, medium risk for Hg and Zn, low risk for Sn, As, Cu and Pb, whereas Sb does not show the risk for the aquatic environment.

Trace element concentrations, ecological and health risk assessment in sediment and marine fish Otolithes ruber in Oman Sea, Iran

This study aimed to investigate the concentration of Cd, Ni, Cr, Pb and As in the tissues of Otolithes ruber and surface sediments in the Oman Sea. Trace element concentrations were analyzed by flame atomic absorption spectrophotometer (FAAS) for ecological and health risk assessment. The results showed a significant difference in trace element concentrations of the liver, muscle and sediments between different stations (p < 0.05). Potential ecological risk index (PER) indicated very high risk for Cd at all stations. Estimated daily intake (EDI) for consumption of Otolithes ruber for Cr, Pb and As was lower than tolerable daily intake (TDI). The mean target hazard quotient (THQ) of Cd and Ni were higher than 1 at all stations. Target cancer risk (TR) for Ni and As were higher than the acceptable value range at all stations. Accordingly, the risk of cancer due to the long-term consumption of this fish can be concerned.

Bioavailability of trace metals in sediments of a recovering freshwater coastal wetland in China's Yellow River Delta, and risk assessment for the macrobenthic community

We investigated the speciation of trace metals and their ecological risks to macrobenthic communities in a recovering coastal wetland of China's Yellow River Delta during the freshwater release project. We established 16 sampling sites in three restoration areas and one intertidal reference area, and collected sediments and macrobenthos four times from 2014 to 2015. The instability index for the trace metals showed a moderate risk for Mn and a high risk for Cd. For both Mn and Cd, the carbonate and FeMn-bound fractions appear to contribute mostly to the instability and bioavailability indexes, but for Cd, the exchangeable fraction also have a much higher contribution. The bioavailability index indicated higher bioavailability of trace metals in freshwater restoration areas than that in the intertidal area. The single-factor contamination index indicated that most trace metal concentrations in the macrobenthos were in excess of the national standard. The biota-sediment accumulation factor suggested that the macrobenthos accumulated most As, Cd, and Cu. Redundancy analysis showed clear relationships between the macrobenthos and sediment metal concentrations. Our results will help wetland managers to assess the bioaccumulation risks based on metal speciation, and to improve management of these recovering freshwater wetland ecosystems.

Disposal Situation of Sewage Sludge from Municipal Wastewater Treatment Plants (WWTPs) and Assessment of the Ecological Risk of Heavy Metals for Its Land Use in Shanxi, China.

Land use of sewage sludge is the primary disposal method in Shanxi, accounting for 42.66% of all. To determine the ecological risk of heavy metals in sewage sludge, contents of seven heavy metals in sewage sludge from 9 municipal waste water treatment plants (WWTPs) that had the highest application for land use were determined. The order of the measured concentrations was: Zn > Cr > Cu > Ni > Pb > As > Cd, and all heavy metals contents were within the threshold limit values of the Chinese Control Standards for Pollutants in Sludge from Agriculture Use (GB4284-84). Four indices were used to assess the pollution and the ecological risk of heavy metals. By the mean values of the geoaccumulation index (Igeo), heavy metals were ranked in the following order: Cd > Zn > Cu > As > Cr > Ni > Pb. The values showed that the pollution of Zn in station 3 and Cd in station 1, 2, 3, 4, 8 and 9 were heavily; Cu in station 8 and 9, Zn in station 1, 2, 4, 8 and 9 and Cd in station 5 and 7 were moderately to heavily, and the accumulation of other heavy metals were not significant. The single-factor pollution index (PI) suggested that none of the stations had heavy metals contamination, except for Cu in station 9, Zn in station 3 and 8, and Cd in station 1 and 9, which were at a moderate level. According to the results of the Nemerow’s synthetic pollution index (PN), sewage sludge from all stations was safe for land use with respect to heavy metals contamination, except for stations 3, 8 and 9, which were at the warning line. The monomial potential ecological risk coefficient () revealed that heavy metals ecological risks in most stations were low. However, station 9 had a moderate risk for Cu; station 6 had a moderate risk, stations 5 and 7 had high risk, other stations had very high risk for Cd. According to the results of the potential ecological risk index (RI), station 1, 8 and 9 had high risk; station 2, 3, 4, 5 and 7 had a moderate risk, and station 6 had a low risk. The preliminary results indicated that the potential risk of land exposure to heavy metals in sewage sludge was relatively low, with Zn and Cd as the main contributor to the ecological risk for the applying of sewage sludge on land. Additionally, stations 3, 8 and 9 require more attention regarding the land applications related to heavy metals pollution.

Geochemical speciation, anthropogenic contamination, risk assessment and source identification of selected metals in freshwater sediments—A case study from Mangla Lake, Pakistan

Geochemical speciation of selected metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr and Zn) using modified BCR sequential extraction procedure was performed in the sediments collected from Mangla Lake, Pakistan. The extraction method was optimized using certified reference material (BCR-701) which showed significant recoveries (95–106%). Among the metals, Cd, Co, Ni, Pb and Sr exhibited relatively higher mobility and bioavailability, while Cu, Fe, Mn and Zn were found mainly in the residual fractions. Principal component analysis (PCA) revealed four groups of the metals in the sediments; I (Cd–Cr–Ni–Sr), II (Co–Pb), III (Fe–Zn), and IV (Mn–Cu); first two groups were mostly contributed by anthropogenic sources. The pollution indicators (individual contamination factor, enrichment factor and geoaccumulation index) revealed significant anthropogenic contamination of Cd, Co, Ni, Pb, Sr and Zn in the sediments. Risk assessment code (RAC) indicated medium risk for Co and Ni; high risk for Cd and Pb; and very high risk for Sr in the sediments. Cluster analysis (CA) and global contamination factor (GCF) were used to identify the pollution hotspots, which indicated more severe metal contamination at sites near to Mirpur city and other urban/semi-urban areas (S3–S5), especially for Cd, Co, Ni, Pb and Sr.

M2055 Time-Course of T-Transglutaminases Antibodies and Adherence to Gluten Free Diet (GFD) Among Celiac Patients in the General Population: Results of a “CD-Watch” Population Based Program

G A A b st ra ct s 21 ± 16.2 U/ml; 10 (5.3%) patients were classified as Marsh 1, 14 (7.5%) Marsh 2 and 163 (87.2%) Marsh 3. Age for the 45 controls was 42 ± 9 years and TTGA level was 0.8 ± 0.1 U/ml. Area under the ROC was 0.98 (95% CI 0.96-0.99 , Std error 0.009, p <0.0001) indicating very high discrimination between CD and non-CD patients (sensitivity 100%specificity 95%). Data of sensitivity, specificity, PPV and NPV for TTGA cut off points for off villous atrophy (Marsh 1-2 vs Marsh 3) are summarized in Table 1. In a population at high risk for CD, TTGA exceeding the upper limit of normal is virtually always associated with CD histopathology, and the level predicts villous atrophy. Because of the highly selected population of our study, results cannot support the concept of avoiding duodenal biopsy for diagnosing CD in average risk patients but this can represent an option in high risk patients or in presence of safety issues precluding biopsy. Sensitivity, specificity, PPV and NPV for TTGA cut-off points for villous atrophy (Marsh 12 vs 3)