High Levels Of Cr Research Articles

Multidrug resistant and extensively drug resistant Acinetobacter baumannii hospital infection associated with high mortality: a retrospective study in the pediatric intensive care unit

BackgroundMultidrug resistant (MDR) and extensively drug resistant (XDR) Acinetobacter baumannii presents challenges for clinical treatment and causes high mortality in children. We aimed to assess the risk factors and overall mortality for MDR/XDR Acinetobacter baumannii infected pediatric patients.MethodsThis retrospective study included 102 pediatric patients who developed MDR/XDR Acinetobacter baumannii infection in the pediatric intensive care unit (PICU) of Shanghai Children’s Hospital in China from December 2014 to May 2018.Acinetobacter baumannii clinical isolates were recovered from different specimens including blood, sputum, bronchoalveolar lavage fluid, cerebrospinal fluid, ascites, hydrothorax, and urine. Antibiotic susceptibility test was determined according to the Clinical and Laboratory Standards Institute interpretive criteria. Clinical and biological data were obtained from the patients’ medical records.Results102 patients with Acinetobacter baumannii infection were enrolled. The median age was 36 (9.6, 98.8) months, and there were 63 male in the case group. The overall mortality rate was 29.4%, while the Acinetobacter baumannii-associated mortality rate was 16.7% (17/102, 12 bloodstream infections, 4 meningitis and 1 intra-abdominal infection). Bloodstream infections occurred in 28 patients (27.5%), and 10 patients (9.8%) among them had central line-associated bloodstream infections (6 central venous catheters, 2 PICCs, 1 venous infusion port and 1 arterial catheter). Cerebrospinal fluid (CSF) cultures were positive in 4(3.9%) patients. 14(13.7%) patients got positive cultures in ascites and hydrothorax. Lower respiratory isolates (56/102) accounted for 54.9% of all patients. Non-survival patients appeared to have a lower NK cell activity (6.2% ± 3.61% vs. 9.15% ± 6.21%, P = 0.029), higher CD4+ T cell ratio (39.67% ± 12.18% vs. 32.66% ± 11.44%, P = 0.039),and a higher serum level of interlukin-8 (IL-8, 15.25 (1.62, 47.22)pg/mL vs. 0.1 (0.1, 22.99)pg/mL, P = 0.01) when Acinetobacter baumannii infection developed. Multivariate logistic analysis indicated that high serum level of Cr (RR, 0.934, 95%CI, 0.890–0.981; P = 0.007) and high BUN/ALB level (RR, 107.893, 95%CI, 1.425–870.574; p = 0.005) were associated with high risk of mortality in MDR/XDR Acinetobacter baumannii infected patients.ConclusionMDR/XDR Acinetobacter baumannii infection is a serious concern in pediatric patients with high mortality. Bloodstream and central nervous system infection accounted for high risk of death. Acute kidney injury is associated with high risk of mortality.

Multiple factors in the prediction of risk of recurrent vitreous haemorrhage after sutureless vitrectomy for non-clearing vitreous haemorrhage in patients with diabetic retinopathy

BackgroundWe aimed to analyse multiple factors in the prediction of risk of postoperative recurrent vitreous haemorrhage (RVH) for non-clearing vitreous haemorrhage in patients with diabetic retinopathy (DR) who underwent sutureless vitrectomy with 23- (23G) or 25-gauge (25G) narrow-gauge systems.MethodsA retrospective consecutive case series design was used. DR patients who underwent sutureless vitrectomy for non-clearing vitreous haemorrhage between June 2017 and October 2019 were enrolled. All operations were performed at a tertiary hospital. Patient demographics and risk factors, including age, gender, duration of diabetes, preoperative fasting blood sugar levels (FBSL), systolic blood pressure (SBP), serum creatinine (Cr), urea, triamcinolone acetonide (TA), electrical coagulation, air-fluid exchange, pan-retinal photocoagulation status (PRP), anti-vascular endothelial growth factor drug (anti-VEGF), and other factors, were recorded. Patients were divided into two groups based on the timing of their postoperative RVH: immediate postoperative RVH (within 2 weeks after operation) and delayed postoperative RVH (beyond 2 weeks after operation).ResultsOverall, 167 eyes (167patients) were enrolled. Seventy eyes were underwent 23G and 25G sutureless vitrectomy performed in 97 eyes, respectively. Postoperative RVH developed in 18 eyes (25.7%) in Group 23G and in 20 eyes (21.6%) in Group 25G (P = 0.540). Of these, 3 eyes (4.3%) had severed RVH in Group 23G compared with 5 eyes (5.2%) in Group 25G (P = 0.584). Delayed postoperative RVH occurred in 6 eyes (8.6%) in Group 23G and 8 eyes (8.2%) in Group 25G (P = 0.789). A binomial logistic regression analysis revealed that age, duration of diabetes, and Cr level were significantly associated with RVH in both Group 23G (P < 0.05) and Group 25G (P < 0.05).ConclusionsThe incidence and severity of RVH were 25.7 and 4.3%, respectively, in Group 23G and 21.6 and 5.2%, respectively, in Group 25G. Thus, the 23G sutureless vitrectomy approach was as safe as the 25G sutureless vitrectomy approach for treating vitreous haemorrhage in patients with DR. A younger age, shorter duration of diabetes, and higher Cr levels were risk factors for postoperative RVH in sutureless vitrectomy.

Geochemistry of a lateritic mantle developed on basalt in the Cameroon Western Highlands (Cameroon Volcanic Line)

Although lateritic mantles have been strongly documented, there is need to continuously characterise and update information at site-scale so as to optimize exploration and exploitation operations in various industrial domains. In this paper, four soil profiles developed on basalt are described in detail to appreciate their morphology, mineralogy, geochemistry, pedogenesis and ore potential. The basalt is composed of olivine, plagioclase feldspars and pyroxenes and accessory magnetite, sphene and apatite. The basalt shows high levels of Ba, Cr, V, Sr, Ni, Zn and Zr; meanwhile total REEs range from 185.03 to 199.45 mg kg−1. The weathering indices reveal an extreme weathering intensity of the parent rock. Newly formed minerals are kaolinite (15–48%), haematite (13–40%), Goethite (10.5–19%) and gibbsite (10–12%), magnetite (4–9.56%), feldspars (4.67–6.10), apatite (2.8–3.9) and sphene (1.77–2.46%). The weathered materials show high levels of Cr (40–850 mg kg−1), V (145–582 mg kg−1), Zr (300–583 mg kg−1) and Ce (24.2–510 mg kg−1). The total REEs of the weathered materials range from 126.52 to 1267.69 mg kg−1, with the predominance of LREE. The REE basalt-normalized patterns revealed slight LREE depletion, more pronounced for the B horizons relative to the underlying C horizons as well as HREE enrichment that increase with depth and altitude. In these soils, mass balance calculations reveal depletion of Si, Ca, Mg, Ba, K, Na, Mn, P, Rb, Sr, La and Lu, enrichment of Al, Fe, Ti, Ga, U, Zr, Dy, Hf, U, Tm and Yb meanwhile Cr, Cs, Sn, Ta, Th, Tl, V, W, Y, Nb, Ce, Pr, Nd, Sm, Eu, Gd, Tb and Ho are either depleted or enriched from one profile to the other. Apart from Cr, V, Zr and Ce whose concentrations respectively attain 850 mg kg−1, 582 mg kg−1, 487 and 510 mg kg−1, the mining potential of the studied lateritic mantle is low.

Concentration and speciation of trace metals and metalloids from road-deposited sediments in urban and rural areas of Beijing, China

Intensive urbanization decreases the self-regulation of urban ecosystems, leading to accumulation of persistent pollutants such as trace metals and metalloids in urban environments. Road-deposited sediments (RDS) are important carriers of trace metals and metalloid contaminants that could contribute to urban runoff pollution. This study aims to investigate the concentration and speciation systemically and assess the risks of trace metals and metalloids from RDS comprehensively. Road-deposited sediments (RDS) were analyzed for As, Cd, Cr, Cu, Mn, Pb, and Zn, in terms of total concentrations, speciation, release, and risks at 23 sites across six land types (the rural-urban fringe, commercial, residential, industrial, traffic, and the natural areas) in Daxing District of Beijing, China, in April 2018. Risk factors evaluating different aspects included contamination levels and ecological risk, Igeo, and RI; source of metal (natural or anthropogenic), EF; bioavailability, RAC. Six particle sizes vs. metal concentrations were also analyzed for trace metals and metalloids from rural-urban fringe samples. Obvious variations were found for the concentrations of Cr, As, and Cd in rural-urban area, especially for Cr. Industrial sites exhibited highest average values for all trace metals and metalloids except for As and Cu. Cr, Cd, and Pb in particular posed more risk. Traffic area showed signs of contamination for Cu, Pb, and Zn. Commercial and residential areas presented low ecological risk. However, there were signs of As and Cu contaminations in both areas, and of Pb in the residential area as well. No research sites were contaminated by Mn, despite the high concentration values. Although high contamination levels of Cr were found in many sites, the risk level of Cr was low. Generally, RDS with smaller particle size (< 80, 80–150, and 150–300 μm) possessed higher concentrations of trace metals and metalloids compared to larger size (300–500 and 500–1000 μm). The study showed that metals of high concentration do not always pose high risk. More attention should be paid to the systematical risk assessment of trace metals and metalloids than the concentration.

Effect of co-application of wastewater and freshwater on the physiological properties and trace element content in Raphanus sativus: soil contamination and human health.

Nowadays, the use of wastewater for crop irrigation is increasing at global scale mainly due to freshwater scarcity and economic benefits. However, the presence of different types of pollutants including the trace elements (TEs) poses a serious threat to environmental and human health. This pot study evaluated the effect of alone and mixed irrigation water [wastewater (WW) with canal water (CW) and tube-well water (TW)] on TEs build-up in the soil, their soil-plant transfer and allied health hazards in District Vehari. The WW samples were mainly contaminated with Cd (0.03mg/L), Cr (1.45mg/L), Cu (0.35mg/L) and Ni (0.40mg/L). The CW contained high levels of Cr and Fe, while TW was contaminated with Pb and Cr. In soil, the concentrations of Cd, Fe and Mn exceeded their respective limit values for all the treatments. Among all the treatments, TEs concentration was found highest in WW-3 irrigated soil. Application of all the treatments resulted in TEs (Cu, 60.1mg/kg; Cd, 8.2mg/kg; Ni, 39.9mg/kg; Fe, 4411mg/kg; Zn, 111.3mg/kg and Pb, 44.5mg/kg) accumulation mainly in the edible parts of Raphanus sativus. Compared to other treatments, TW and TW + CW irrigated plants accumulated higher levels of TEs. Results showed linear trends among TEs accumulation and alterations in physiological attributes of R. sativus. High TEs accumulation in TW irrigated treatments (TW + WW-1 and TW + CW) caused maximum H2O2 production, lipid peroxidation and decline in plant pigments. Risk assessment parameters showed both carcinogenic and non-carcinogenic risks for all the irrigation treatments due to high TEs contents in edible tissues. It is concluded that alone or combined application of WW, TW and CW is not fit for vegetable irrigation, in the studied area, due to high TEs contents.

Detoxification of wood-combustion ashes containing Cr and Cd by thermal treatment

This study assesses the potential of thermal processing for detoxification of wood-combustion ashes that contain high levels of Cr and Cd. Thermal treatment (1000 °C) of bottom ash and fly ash in an oxidising gas (air) atmosphere resulted in: low volatilisation of Cd and most other heavy metals, oxidation of Cr in the ashes to Cr (VI), and, in the case of the fly ash, significantly increased leaching of Cr and Mo. Thermal treatment in a nitrogen atmosphere resulted in local reducing conditions due to oxidation of ash-derived carbon to CO (g). Thermal treatments in this atmosphere and in a reducing atmosphere consisting of 10 % H2 and the balance N2 detoxified the ashes in at least two ways: (i) by substantially removing Cd, Pb, Bi, Tl, and, in the case of the fly ash, Zn from the ashes by volatilisation; and (ii) by thermal reduction of Cr (VI) in the ashes. There was at least a 100-fold reduction in the leaching of total Cr from both the bottom ash and the fly ash following the thermal treatments in reducing conditions. Chromium only leached from the detoxified bottom ash to a significant extent in acidic conditions (pH < 4).

Importance of Preanalytical Factors in Measuring Cr and Co Levels in Human Whole Blood: Contamination Control, Proper Sample Collection and Long-Term Storage Stability.

A number of errors with potentially significant consequences may be introduced at various points in the analytical process, which result in skewed, erroneous analytical results. Precautionary procedures such as contamination control, following established sample collection protocols, and having a complete understanding of the long-term stability of the elements of interest can minimize or eliminate these errors. Contamination control is critical in the quantification of Cr and Co in human whole blood. Cr and Co levels in most biological samples are low, but these elements occur naturally in the environment and are often found in commercial and consumer products, which increases the risk of contamination. In this paper, we demonstrated that lot screening process in which we pre-screen a sub-set of manufactured lots used in collecting, analyzing and storing blood samples is a critical step in controlling Cr and Co contamination. Stainless steel needles are often utilized in blood collection but are considered as a potential source of introducing metal contamination to the patient sample. We conducted two studies to determine if there is a possibility of Cr or Co leaching into the human whole blood from the needles during blood collection. We analyzed blood collected from 100 donors and blood collected in vitro in the laboratory from designated vessel containing spiked blood with higher levels of Cr and Co. Two blood tubes were consecutively collected through one needle. In both studies, Cr and Co concentration levels in the two consecutively collected tubes were compared. Based on the results from donor and in vitro blood collection studies, we concluded that there was no Cr and Co leaching from the limited sets of stainless steel needles used in these studies. Furthermore, we demonstrated that Cr and Co human whole blood samples are stable for 1 year stored at temperatures of -70, -20 and 4°C and 6 months at room temperature.

Levels of heavy metals in wastewater and soil samples from open drainage channels in Nairobi, Kenya: community health implication

Levels of Mercury (Hg), Lead (Pb), Cadmium (Cd), Chromium (Cr), Nickel (Ni) & Thallium (Tl) were established in wastewater & soil samples obtained from 8 sites in open drainage channels at Nairobi industrial area, Kenya. Ultra-trace inductively coupled plasma mass spectroscopy (ICP-MS) was used for metal analysis. Temperature, pH & turbidity of wastewater ranged from 16.75 to 26.05 °C; 7.28 to 8.78; 160.33 to 544.69 ppm respectively and within World Health Organization (WHO) allowable limits. Wastewater conductivities in 4 sites ranged from 770 to 1074 µS/cm and above WHO limits at 25 °C. The mean concentrations of the metals in wastewater ranged from 0.0001 to 0.015 ppm in an ascending order of Tl <Cd <Hg <Ni <Cr <Pb. Levels of Cd, Cr & Ni in wastewater were within WHO, World Bank (WB), United States Environmental Protection Agency (US EPA), China, Kenya and India’s Central Pollution Control Board (CPCB) limits while Hg & Tl were above US EPA limits. The mean Pb levels in wastewater (5 sites) were above WHO, US EPA and Kenya allowable limits. Mean levels of the metals in soil samples ranged from 0.085 to 199.99 ppm, with those of Hg, Pb, Cr, Cd & Ni being above WHO limits for agricultural soils. Positive correlations (P < 0.05) for Cd & Hg in soils; and Tl (wastewater) & Cd (soil) were noted. In conclusion, wastewater in open waste channels at Nairobi industrial area had elevated levels of Pb and Hg, while the soil from the same channels had high levels of Hg, Pb, Ni, Cr, and Cd. Good management of Nairobi industrial area effluents is inevitable since it borders densely populated informal settlements which are likely to suffer exposure to toxic wastes. Effective wastewater treatment and reuse is highly recommended.

T27. COGNITIVE RESERVE IN CHILD AND ADOLESCENT OFFSPRING OF PATIENTS DIANOSED WITH SCHIZOPHRENIA OR BIPOLAR DISORDER

BackgroundCognitive Reserve (CR) is defined as the ability of the brain to cope and deal with physiological or pathological brain injuries. In the field of psychiatry, higher levels of CR have been associated with lower levels of psychotic symptoms, higher psycho-social functioning and higher cognitive performance, suggesting that CR should be considered as a protective factor (Barnett et al., 2006; Amoretti et al., 2016). This study aims to compare CR levels in a sample of adolescents and young adult offspring of patients with schizophrenia or bipolar disorder who are at high risk of developing these disorders (HR) and compared them with a group of healthy controls (HC). We also assess the utility of CR in predicting clinical and cognitive variables.MethodsParticipants were 85 HR and 45 HC. A CR proxy was calculated based on premorbid IQ, socio-occupational attainment and social activities. Clinical assessment included: the Structured Interview for Prodromal Symptoms (SOPS), the Young Mania Rating Scale (YMRS) and the Hamilton Depression Rating Scale (HDRS). Neuropsychological assessment included: Working Memory, Processing Speed, Verbal Memory, attention and executive functioning. A factorial analysis was conducted in order to obtain a single CR measure. Differences between groups in CR were assessed via MANCOVA and linear regressions were conducted to check the effectiveness of CR in predicting clinical and neuropsychological variables.ResultsNo significant differences were observed in age or gender between HR and HC groups. Socioeconomic status was lower in HR subjects (F=8.100, p=0.005).CR was significantly lower in the HR group than in the HC group (F=17.522; p<0.001). Moreover, the CR proxy was able to correctly classify 72.7% of the sample as either HR or HC. Our proxy was able to predict the following clinical variables in the HR group: negative (F=9.269; p=0.002), and total (F=7.290; p=0.009) prodromal symptoms, the YMRS (F=11.597; P<0.001) and the HDRS (F=12.761; p<0.001). In terms of neuropsychological variables, RC predicted WM (F=9.738; p=0.003), PS (F=4.557; p=0.037) and verbal memory [immediate (F=6.999; p=0.010) and delayed recall (F=10.990; P=0.002)] in the HR sample.DiscussionHR subjects have lower CR than controls. CR is associated with clinical and neuropsychological variables. To our knowledge no previous studies have assessed CR in high risk samples. Nevertheless, studies conducted in adult first episode psychotic samples have shown an association between CR and the severity of symptoms.

Geochemical behavior and potential health risk of heavy metals in basalt-derived agricultural soil and crops: A case study from Xuyi County, eastern China

Basalt-derived agricultural soil is widely distributed around the world and is extensively used as a medium to plant many kinds of crops. Weathering of basalt can release heavy metals into the soils and may cause health risks via the food chain. However, the geochemical behavior and the potential human health risks of heavy metals remain poorly understood in these agro-systems. In this study, basalt bedrock, paired topsoil and crops (wheat and rice) samples were collected from a basaltic area located in Xuyi County, eastern China. Concentrations and bioavailability of heavy metals in the basalt-topsoil-crop system were measured to determine their geochemical behavior during the weathering and transfer processes as well as their potential risk to human health. Our results showed that basalt and topsoil were characterized by high levels of Ni, Cr and Zn. Topsoil and crop grains were highly polluted by Ni, and Ni accumulated more readily in rice grains than in wheat grains. Nickel, a high-risk metal in topsoil was mainly derived from the basalt bedrock, and its enrichment in topsoil was significantly related to the Fe oxide content of the soils. The accumulation of Ni in crop grains was mainly controlled by soil pH, and the 0.01 M CaCl2 extractable Ni was a good indicator in predicting Ni accumulation in crop grains. Risk analysis revealed that there are significant health risks to local inhabitants if rice grains contaminated with heavy metals are ingested. To our best knowledge, this is the first study to investigate the flow of heavy metals in a basalt-topsoil-crop-human system that focuses on geochemical behavior and human health risk. This study will aid the strategic design of evaluation and remediation protocols for basaltic soil.

Evaluation of Levels of Cadmium, Chromium and Lead in Bio Fertilizer from Various Feed Stocks and in Inorganic Fertilizers Used in Kenya

This study was conducted to compare the levels of selected heavy metals (Pb, Cr and Cd) in inorganic fertilizers and bio slurry from different feed stocks. Bio slurry samples from chicken droppings, cow dung and pig wastes were analyzed for levels of selected heavy metals. Inorganic fertilizers for analysis DAP, CAN, Urea and NPK were procured from local market in Juja town next to Jomo Kenyatta University of Agriculture and Technology (JKUAT). Bio slurry samples were collected from Githunguri Sub County in Kiambu County and from mini digesters set up at JKUAT. Concentrations of Cd, Cr, and Pb were determined by Flame Atomic Absorption Spectrophotometer (Shimadzu 6200). Inorganic fertilizers were found to contain detectable amounts of lead metal. DAP had the highest amount of Pb at 0.03 mg/l followed by CAN (0.02 mg/l) Urea and NPK had 0.01 mg/l each. Bio slurry samples contained lower amounts of lead which was below detectable limit in chicken litter and pig wastes. Inorganic fertilizers contained Cd with the highest levels being in the phosphorous containing fertilizers DAP (0.41 mg/l) and NPK (0.48 mg/l). All samples contained Cr with the highest in bio slurry samples being 0.09 mg/l in cow dung collected from Githunguri. CAN had the highest level of Cr (0.08 mg/l) among the inorganic fertilizers. Bio slurry is a better alternative fertilizer in reducing heavy metal uptake and their subsequent bioaccumulation.

Influence of soil properties on the bioaccessibility of Cr and Ni in geologic serpentine and anthropogenically contaminated non-serpentine soils in Taiwan

Serpentine minerals with high levels of geologic chromium (Cr) and nickel (Ni) and non-serpentine farmlands polluted by irrigation water causing high anthropogenic Cr and Ni levels are both found in Taiwan. Elevated levels of Cr and Ni in these soils are a concern due to their potential to promote cancer mortality in humans. Bioaccessibility is a crucial factor determining the actual health risk via oral ingestion when children are exposed to metal-contaminated soils. Furthermore, the bioaccessibility of metals varies with the source, soil properties, and fractionation of metals in the soil. Therefore in this study, soil pH, total organic carbon (TOC), texture, and the total concentrations, fractionation, and bioaccessibility of Cr and Ni were analyzed and correlated for soils collected from serpentine mineral-containing deposits and contaminated non-serpentine farmlands. The low bioaccessibility and low mobility of Cr and Ni in serpentine soils suggested that incidental ingesting of soils posed a low health risk; however, the higher bioaccessibility and mobility of Ni in non-serpentine soils contaminated by electroplating wastewater could lead to potential risks for humans. Additionally, a significant difference in the bioaccessibility of Ni was observed between serpentine and non-serpentine soils, but this was not shown for Cr. Accordingly, a correlation analysis showed that Cr bioaccessibility was positively correlated with TOC, with no distinction between serpentine and non-serpentine soils. In contrast, TOC and the fractions of the sequential extraction procedure were significantly correlated with Ni bioaccessibility both in anthropogenically contaminated non-serpentine soils and in natural serpentine soils.

Heavy Metals Contents of Municipal Solid Waste Dumpsites in Potiskum, Yobe State Nigeria

The concentrations of As, Cd, Cr, Cu, Ni, Pb, Fe and Zn in selected dumpsites in Potiskum were determined with Buck Scientific 210VGB Atomic Absorption Spectrometer (AAS) AVG 210. One-way ANOVA was deployed at p ·kg-1) of studied heavy metals in Potiskum dumpsites ranged from 0.108 ± 0.02 - 262.536 ± 0.68 with pattern of accumulation Pb (262.536 ± 0.02) > Zn (183.369 ± 0.58) > Fe (159.453 ± 0.50) > Cu (111.382 ± 0.62) > Cr (43.523 ± 0.36) > Ni (6.419 ± 0.26) > Cd (0.679 ± 0.01) > As (0.108 ± 0.02) mg·kg-1. The concentrations of As, Cr, Ni, Fe and Zn fell below the WHO standards while those of Pb, Cd and Cu were above set limits by WHO. High acidity corresponds markedly with high levels of Cd, Cu, Cr and Zn and requires urgent attention as this trend is capable of groundwater contamination that will cause public health concern in affected areas.

Heavy metals in iron ore tailings and floodplain soils affected by the Samarco dam collapse in Brazil

In November 2015, the Fundão Dam collapsed releasing about 35 million m−3 of iron ore tailings into the environment, which covered approximately 15 km2 of floodplain soils. Four years later, there is still great concern and controversy regarding contamination by heavy metals in the affected areas. Thus, the present study sought to evaluate the heavy metal contents and its distribution in tailings and non-affected soils. Tailings samples were collected in the stretch between Bento Rodrigues and the Candonga hydroelectric plant, in addition to a sample inside the Fundão Dam. Non-affected soils and river sediments from the same region were also collected as a control group. The heavy metal contents in the tailings were lower than in non-affected samples from the same area, discarding the hypothesis of contamination by the tailings mud. The non-affected samples presented high levels of As, Ba, Co, Cr, Cu, Ni and Zn, with at least one sample exceeding the quality reference values (QRV's) established for Minas Gerais state, which indicated a scenario of pre-disaster contamination for the Doce River watershed. Most of the elements (As, Cr, Cu, Ni, V and Zn) were extracted in the residual fraction of the BCR sequential extraction, presenting low risk of release in nature. The health risk assessment for As estimated that all the non-affected soils and sediments from Gualaxo do Norte, Carmo and Doce rivers have carcinogenic risk higher than the acceptable value for children. From our results, it is more likely to conclude that the deposited tailings are not a time-bomb for heavy metals contamination in the region.

Composite assessment of human health risk from potentially toxic elements through multiple exposure routes: A case study in farmland in an important industrial city in East China

Accumulation of potentially toxic elements (PTEs) in farmland soils and agricultural products is an issue of considerable concern related to food safety and human health. Assessment of composite health risks caused by exposure to PTEs through different pathways and the spatial probability of these risks could help in soil management and reduction in the corresponding human health risk. In this study, we collected 932 soil samples and corresponding samples of rice planted at the same locations in an industrial city in eastern China. The composite human health risk, including the health risks caused by Cr, Pb, Cd, Hg, As, Cu, Zn, and Ni from soil inhalation, ingestion, and dermal contact combined with the consumption of rice were assessed. Sequential Gaussian stochastic simulation and probability kriging were employed to explore the spatial pattern of the composite health risk. The results showed that 13.52%, 5.47%, 2.68%, 2.58%, 1.61%, 0.86%, and 0.21% of soil samples collected from the study area were polluted by Hg, Cd, Pb, Cu, Zn, Ni, and Cr, respectively. Furthermore, 65.02%, 20.28%, 10.94%, 4.72%, 0.75%, 0.11%, and 0.11% of rice samples were polluted by high levels of Ni, Cr, As, Cd, Pb, Hg, and Zn, respectively. Children had a higher hazard index than adults for non-carcinogenic health risks. Both children and adults had potential carcinogenic risks. The largest contributor to non-carcinogenic health risks was As, whereas Ni was the largest contributor to carcinogenic risk. Consumption of contaminated rice accounted for >90% of the total non-carcinogenic and carcinogenic health risks, suggesting that PTEs accumulation in rice could exert harmful effects on human health. In terms of their spatial patterns, both non-carcinogenic and carcinogenic risks were associated with areas with a high density of anthropogenic activities. Residents in most areas in the study region have a high probability of experiencing significant carcinogenic and non-carcinogenic health effects caused by exposure to PTEs. Children have a higher probability of non-carcinogenic health risk than adults across the study area. The results revealed that consumption of contaminated crops poses essential potential health risks to humans. Measures should be undertaken to reduce the content of contaminated PTEs in farmland soils and rice, and children should be listed as a priority for protection from exposure to PTEs.

Formation Causes and Preventive Measures of the Scale of 600MW Unit High Temperature Reheater Tubes

It was found obvious accumulation of scale at the elbow of a high temperature reheaters, by measuring scale accumulation of boiler high temperature reheater SA213-TP347H steel pipe of a power plant. By hardness test, tensile test, optical microscopy and spectroscopy analysis of the pipe sample, it was showed that hardness test results meet DL / T 438-2009 standard requirements; mechanical properties test results meet GB 5310-2008 standards. The microstructure of cross-sectional sample is austenite. EDS analysis result shows that the scale mainly composed of Fe, Cr, Ni oxide. There is obvious stratification in the scale of austenitic stainless steel, the inner layer scale has higher levels of Cr and Ni, Fe and O content is relatively low, which has antioxidant. Fe and O content of the outer layer of skin is relatively high, low Cr and Ni content, leading to its outer oxide does not have the ability of anti-oxidation. There are gathered holes between the inner and outer layers. Temperature change process will produce stress, resulting in oxidation of the outer layer of skin off. Finally, a few precautions to prevent the scale spalling are proposed.

Enhanced chromium(VI) treatment in electroactive constructed wetlands: Influence of conductive material

A constructed wetland (CW) microcosm based on conductive graphite gravel was investigated for hexavalent chromium (Cr(VI)) treatment from synthetic wastewater. Its performance was evaluated and compared with a traditional gravel-based CW microcosm. The microcosms were operated at varying initial Cr(VI) concentrations (5−20 mg/L) and hydraulic retention times (HRT) (3–7.5 h). Near complete treatment (99.9 ± 0.06 %) was achieved in the graphite-based microcosm throughout the experiment. The performance was consistently high throughout with 42.9 % improvement in Cr (VI) treatment compared to a traditional gravel microcosm. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) analysis indicated that chromium was adsorbed to microbial biofilms. Moreover, microbial diversity profiling suggested that the microbial population in both microcosms differed in diversity and communities. The results suggest that the use of conductive materials in CW significantly enhances the treatment of Cr(VI) and more importantly, allows microbial activity even at high levels of Cr(VI) in the CW.

Trace Elements in the Lung Tissue Affected by Sarcoidosis.

In the lungs of 76 patients with verified sarcoidosis, 28 chemical elements were identified with neutron activation analysis. High levels of Ca, Fe, Cr, Co, Cs, Eu, Lu, Th, Hf, Au, and U and low level of Na compared to the control samples were determined in sarcoidosis. There were no significant differences in the content of Zn, Rb, La, Sm, Sr, Nd, As, Br, Ag, Tb, Sc, Ta, Sb, Ba, and Yb. Spearman correlation analysis shows multiple positive associations, with the maximum being in pairs as follows: Fe-Cr, Eu-La, Ce-Lu, Hf-Cr, Sc-Zn, Fe-Hf, Ce-Co, and Sb-Cr. These studies support the hypothesis that sarcoidosis is a response of the organism in the form of granulomatous inflammation when exposed to heavy metals and rare earth elements in the environment. We assume that the role of calcium and iron is to separate granulomas from the tissues of the body.

Chromium tolerance and accumulation in Aspergillus flavus isolated from tannery effluent

Cr(VI) tolerance in Aspergillus flavus, strain SFL, isolated from tannery effluent was measured and compared with a reference strain of A. flavus, A1120. On solid medium, SFL had a high level of Cr(VI) tolerance (1,600 mg/L), which was 16 times that of A1120 and greater than most previously analyzed fungal strains. When in 100 mg/L of Cr(VI), SFL completely depleted Cr(VI) within 72 h while A1120 depleted 85% of Cr(VI). SFL was more effective in reducing extracellular Cr(VI) than A1120. While A1120 showed greater biosorption of Cr(VI) than SFL, intracellular accumulation was approximately 50% greater in SFL and was more energy-dependent than A1120. Cr(VI) modified the external surface of the hyphae. Cr speciation detected the presence of only Cr(III), corresponding to Cr(OH)3 , which precipitated on the hyphal surface. Cr(VI) bound to the functional groups carboxyl, amine, and hydroxyl in both SFL and A1120. Transmission electron microscopy energy-dispersive X-ray detected Cr on the fungal wall and within membrane-bound organelles of the cytoplasm. In conclusion, the greater tolerance of SFL to Cr(VI) relative to A1120 is due to more effective energy-dependant uptake of Cr(VI) into the cell and increased capacity of SFL to store Cr in intracellular vacuoles compared with A1120.

Reproductive Hormones among Electroplaters Exposed to Chromium and Nickel at a Factory for Metallic Industries in Egypt

Introduction: Exposure to chromium (Cr) and nickel (Ni) is prevalent at workplace. Although they are toxic,human studies on their effect on the reproductive system are few and contradictory. Aim of work: To evaluatethe association of male reproductive hormone levels with the concentrations of blood chromium and nickelamong electroplaters in a factory for metallic industries in Egypt. Materials and methods: A cross sectionalcomparative study was conducted on 48 electroplating workers and 48 non-occupationally exposed subjectsused as controls. Personal interview with specially designed questionnaire were fulfilled. Blood nickel andchromium concentrations were determined and the reproductive hormones levels [follicle stimulating hormone(FSH), luteinizing hormone (LH), testosterone and inhibin] were assayed for all participants. Results: Thestudy showed a statistically significant high levels of the mean values of blood Cr and Ni among electroplatingworkers compared to the control group (1.2±0.93 and 1.3±1.02 μg/L vs 0.4±0.1 and 0.39±0.2 μg/L respectively;p<0.001). Also, a statistically significant high levels of FSH and LH were detected among exposed workers(5.19±2.08 mIU/L and 6.85± 2.67 IU/L respectively) compared to controls (1.95±0.7 mIU/L and 3.97± 0.85IU/L respectively) with low levels of testosterone and inhibin. Significant positive correlations (p<0.05)were found between FSH level and heavy metals (Cr and Ni) levels (r=0.28 and r=0.63; p=0.05 and p<0.002respectively). Conversely, significantly negative correlations were detected as regards testosterone level (r=-.323 for chromium and r=-.571 for nickel; p<0.05 for each). Blood nickel was found to be a significant predictorfor FSH and testosterone level, and smoking index was predictor for all measured reproductive hormonesamong exposed electroplaters. Conclusion: Exposure to high levels of Cr and Ni might affect reproductivehormones levels among male electroplating workers. Regular wearing of good quality’s personal protectiveequipment, especially masks and gloves, to decrease exposure to electroplating fumes, is highly recommended.