H-vector Research Articles

Assessment of EDDS and vermicompost for the phytoextraction of Cd and Pb by sunflower (Helianthus annuus L.)

The effects of Ethylenediamine disuccinic acid (EDDS) (0 and 5 mmol·kg−1) as a synthetic chemical amendment, vermicompost (0 and 5%w/w) as an organic amendment and their combined application were evaluated for the phytoextraction by sunflower (Helianthus annuus L.) of cadmium (Cd) and lead (Pb) at three artificial contamination levels in soils (0, 50, and 100 mg·kg−1 for Cd and 0, 100, and 200 mg·kg−1 for Pb). The results showed that the application of EDDS was the most effective method to increase Pb and Cd concentrations in both parts of the plant. The results also showed that the application of EDDS increased 9.27% shoot Pb content at 200 mg·kg−1 but decreased 15.95% shoot Cd content at 100 mg·kg−1 contamination level with respect to the respective controls. The bioavailable concentrations of Cd at 100 mg·kg−1 and Pb at 200 mg·kg−1 contamination level in the soil at the end of experiment increased 25% and 26%, respectively after the application of EDDS but vermicompost decreased 43.28% the bioavailable Pb concentration relative to their controls. Vermicompost increased the remediation factor index of Cd, thus making it the best treatment for the phytoextraction of Cd. The combined application of EDDS and vermicompost was the best amendment for Pb phytoextraction.

Spatial Variations of Soil Heavy Metal Potential Ecological Risks in Typical Moso Bamboo Forests of Southeast China.

Spatial patterns of soil heavy metal potential ecological risk are important for the scientific pollution management of bamboo forests. A total of 160 soil samples were collected from typical moso bamboo forests in the southeastern region of China. Ecological risk index and GIS-based kriging methodologies were applied to analyze spatial variations of analyzed metals and were compared to background levels in samples collected from Zhejiang Province. The results show that the exceeded background rate of the single-factor pollution index of Pb, Cd and Cu in all soil samples is greater than 50%, with the highest overbackground rate of Pb being 99.38%. The potential ecological risk of Hg, Pb and Cd reaches a stronger risk level, while other heavy metals such as As, Cu and Cr are associated with a slight risk level. Different spatial patterns across the whole study area indicate that the potential ecological risk in the northwest and southeast areas is high, but is relatively low in the north-central area.

P016] Performance of 3 CT scanners: Results from a 4 year period

Purpose Present the results of a 4 years period quality control routine test performed on 3 CT scanners (Siemens Somaton Sensation Open (S), Toshiba Aquilion 16 (T) and Ge HiSpeed Lx/i (G)) to assure compliance of the monitored parameters with baseline values and detect system performance malfunctioning. The weekly test, is a 15 minute check acquisition of the CATPHAN 600 phantom sections. Methods Baseline values were established using the average of 10 images in sequential mode 120 kV, 200 mAs(T), 280 mAs(S) and 300 mAs(G), collimation 1 × 5 mm(SG 31 mGy(G); 35 mGy(S). Performance indicators: Noise Index (standard deviation of the HU measured in a central ROI of 28 cm[b] (40% useful radius) Homogeneity index (maximum difference on the average HU measured in 4 periphery ROI’s relative to a central ROI each with 10cm2); Spatial Resolution Index (zoomed visualization of the last perceptible group of a lp/cm pattern using constant WW, WL); Low Contrast Index (CD – diameter * percentage contrast (mm*%) for each target – 3 groups of different sized low contrast targets 10HU, 5HU, 3HU – 2 images averaged; HU index (average HU in 45 mm[b] ROI’s of 8 target materials from −1000 up to 1000 HU. Results Noise index: σ(T) = 5.36 ± 2%; σ(G) = 2.87 ± 3%; σ(T) = 4.01 ± 5%; maximum deviations: 8.6%(T); 3.1%(G); 4.7%(S); outliers(>10%): two (12.3;16.0%(T)); one 21.6%(G); zero(S). Homogeneity index: HU = 9.53 ± 4%(T); HU = 7.1 ± 3%(G); HU = 12.7 ± 3%(S); maximum difference deviations: 14.7%(T); 14.5%(G); 12.6%(S); outliers(>15%): six(16.7;15.7%(T)) one 24.2%(G); zero(S). Spatial Resolution index (lp/cm): 9(T); 7(G); 8(S); CD index (mm*%): Conclusions The customized test proved to be a simplified but incomplete method for system performance consistency evaluation since it was inefficient in the detection of ring artifacts caused by faults in detector system calibration for the head protocol. The addition of a spiral acquisition in the homogenous section, lead to direct visualization and awareness of this type of artifacts but still do not prevent the detection of artifacts in larger FOVs or in special collimation sets depending on the CT scanner design.

Pollution characteristics of atmospheric dustfall and heavy metals in a typical inland heavy industry city in China

Through field sampling of atmospheric dustfall in regions of Zhuzhou City, China for a period of one year, the deposition fluxes of atmospheric dustfall and five heavy metals contained inside, including Cr, As, Cd, Hg and Pb, were analyzed. Meanwhile the enrichment factor and index methods were used to analyze the pollution characteristics of heavy metals of atmospheric dustfall in Zhuzhou. The annual deposition flux of atmospheric dustfall in Zhuzhou was 50.79 g/(m2·year), while the annual deposition fluxes of Cr, As, Cd, Hg and Pb were 9.80, 59.69, 140.09, 0.87 and 1074.91 mg/(m2·year), respectively. The pollution level of atmospheric dustfall in Zhuzhou was relatively lower compared with most other cities in China, but the deposition fluxes of As, Cd, Hg and Pb in atmospheric dustfall in Zhuzhou were much higher than that in most cities and regions around the world. Cd is the typical heavy metal element in atmospheric dustfall in Zhuzhou, and both the enrichment factor and pollution index of Cd were the highest. Cd, Hg, Pb and As in atmospheric dustfall were mainly from human activities. According to the single-factor index, Nemerow index and pollution load index analyses, the atmospheric dustfall in Zhuzhou could easily cause severe heavy metal pollution to urban soil, and the most polluting element was Cd, followed by Pb, As and Hg. Only the pollution level of Cr lay in the safety region and mainly originated from natural sources.

Deciphering adverse effects of heavy metals on diverse wheat germplasm on irrigation with urban wastewater of mixed municipal-industrial origin.

The current study provides one of the first attempts to identify tolerant, moderately sensitive, and highly sensitive wheat genotypes on the basis of heavy metal accumulation, biochemical attributes, and human health risk assessments on urban wastewater (UW) irrigation. Mean heavy metals (Fe, Co, Ni, Cu, Zn, Pb, Cd, Cr, Mn) and macro-nutrients (Na, K, Ca, Mg) levels increased in the roots, stem, and grains of studied genotypes. Except K (stem > root > grain), all metals were accumulated in highest concentrations in roots followed by stem and grains. Principal component analyses (PCA) identified three groups of UW-irrigated genotypes which were confirmed by hierarchical agglomerative cluster analyses (HACA). Wheat genotypes with the lowest metal accumulation were regarded as tolerant, whereas those with maximum accumulation were considered highly sensitive. Tolerant genotypes showed the lowest hazard quotient for heavy metals, i.e., Co, Mn, Cd, Cu, Fe, Pb, and Cr, and hazard index (HI) values (adults, 2.04; children, 2.27) than moderately and highly sensitive genotypes. Higher health risks (HI) associated with moderate (adults 2.26; children 2.53) and highly sensitive (adults 2.52; children 2.82) genotypes revealed maximum uptake of heavy metals. The heatmap showed higher mean biochemical levels of chlorophyll, carotenoids, membrane stability index (MSI%), sugars, proteins, proline, superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in tolerant genotypes than remaining genotypes. With the lowest metal accumulation and advanced biochemical mechanisms to cope with the adverse effects of heavy metals in their plant bodies, tolerant genotypes present a better option for cultivation in areas receiving UW or similar type of wastewater.

Assessment of Soil Environmental Quality in Huangguoshu Waterfalls Scenic Area

This paper concentrates on five major heavy metal pollutants as soil environmental quality evaluation factors, respectively Lead (Pb), Cadmium (Cd), Mercury (Hg), Arsenic (As), Chromium (Cr), based on the National Soil Environmental Quality Standards (GB15618 - 1995), we used single factor index evaluation model of soil environmental quality and comprehensive index evaluation model to analyze surface soil environmental quality in the Huangguoshu Waterfalls scenic area. Based on surface soil analysis, our results showed that the individual contamination index, Pb, Hg, As and Cr in the Huangguoshu Waterfalls scenic area met class I according to requirements of National Soil Environmental Quality Standards, which indicated that Pb, Hg, As and Cr were not main heavy metal pollutants in this area, but the individual contamination index of Cd in soil was seriously exceeded National Soil Environmental Quality Standards’ requirement. Soil environmental quality in Shitouzhai, Luoshitan, Langgong Hongyan Power Plant have exceeded the requirement of National Soil Environmental Quality Standards “0.7< Pc≤ 1.0” (Alert Level), these soils had been slightly polluted; the classification of soil environmental quality assessment in Longgong downstream area was above “Alert Level”, it indicated that soil in this area was not polluted. Above all, relevant measures for soil remediation are put forward.

Epidemiological Study on Metal Pollution of Ningbo in China.

Background: In order to search for effective control and prevention measures, the status of metal pollution in Ningbo, China was investigated. Methods: Nine of the most common contaminating metals including lead (Pb), cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), chromium (Cr), nickel (Ni), zinc (Zn), and mercury (Hg) in samples of vegetables, rice, soil, irrigation water, and human hair were detected using inductively coupled plasma-mass spectrometry (ICP-MS). Three different districts including industrial, suburban and rural areas in Ningbo were studied through a stratified random sample method. Results: (1) Among all of the detected vegetable samples, Cd exceeded the standard limit rates in industrial, suburban and rural areas as high as 43.9%, 27.5% and 5.0%, respectively; indicating the severity of Cd pollution in Ningbo. (2) The pollution index (PI) of Cd and Zn in soil (1.069, 1.584, respectively) suggests that soil is slightly polluted by Cd and Zn. Among all samples, metal contamination levels in soil were all relatively high. (3) A positive correlation was found between the concentrations of Pb, Cd and Cu in vegetables and soil; Pb, Cu, Cr and Ni in vegetables and irrigation water, as well as, Cu and Ni in rice and irrigation water; and, (4) Higher Pb and Cd concentrations were found in student scalp hair in both industrial and suburban areas compared to rural areas. (5) Hg and Pb that are found in human scalp hair may be more easily absorbed from food than any of the other metals. Conclusions: In general, certain harmful metal pollutions were detected in both industrial and suburban areas of Ningbo in China.

High-Dosed Intravenous Iron Replacement Therapy for Iron Deficiency Anemia Does Not Hinder Drug-Induced Amelioration of Disease Activity in IBD Patients

BACKGROUND: Iron deficiency and iron deficiency anemia (IDA) are common complications in IBD patients, and can seriously affect quality of life, hospitalization rates, and time lost from work. In IBD patients, anemia is caused by chronic blood loss and/or impaired iron intake and absorption. International guidelines recommend intravenous iron supplementation in IBD patients with moderate-severe anemia or intolerance to oral iron. While oral supplements are convenient and relatively inexpensive, they fail to compensate continuous iron loss due to inadequate intestinal absorption in the presence of inflammation. Oral iron intake is associated with gastrointestinal side-effects including abdominal pain and nausea. Moreover, mounting evidence from animal and human studies shows that non-absorbed iron enhances mucosal inflammation. Intravenous iron has been demonstrated to be safe, effective and well tolerated in correction of IDA and maintenance of iron stores in patients with IBD. Intravenous ferric carboxymaltose (FCM; Ferinject® 50mg ferric iron(III)/mL suspension) can be administered in single 15-minute infusions of up to 1,000mg per week. Here, we assess the effect of high-dosed intravenous FCM on inflammatory activity in IBD patients. METHODS: A prospective non-interventional post-marketing study was performed in 101 centers in Germany to assess efficacy, tolerability, and convenience of Ferinject® in clinical practice. Alongside primary outcomes including response rates and adverse events, changes in clinical disease indices (CDAI/CAI), changes in CRP values, and self-reported disease-related symptoms (fatigue, concentration lack, headache, paleness of mucous membranes, hair loss, (exertional) dyspnoea, sleeping disorders, restless legs syndrome) rated on a severity scale of 1 to 4, were analyzed. Patients were additionally analyzed in subgroups according to baseline CRP levels (<5mg/L, >5mg/L, 5-10mg/L, >10mg/L). RESULTS: Intravenous FCM was administered to 224 subjects (127 CD; 97 UC). Mean total iron dose over ca. 12 weeks was 1,139mg (range: 100mg-4,800mg). 76.7% of doses were between 500mg and 2,000mg. Concomitant drugs included aminosalicylates (89 patients/46.1%), corticosteroids (84/43.5%), immunosuppressants (36/18.7%), biologics (36/19%), antibiotics (8/4.1%) and antidiarrheics (11/5.7%). Although patients (n=97) with elevated CD or UC activity indices (CDAI ≥150; CAI ≥5) presented with lower mean Hb values at baseline compared to those with normal activity indices, mean Hb levels at end of study (EOS) were similar. Subjects with higher activity indices presented with higher mean CRP values at baseline (6.1mg/L) compared to those with normal activity indices (3.6mg/L). CRP levels decreased significantly during the observation period, falling from 6.4mg/L to 3.5mg/L in mean (median 1.9 -1.0mg/L), indicating a general reduction in inflammatory activity, which was independent of baseline Hb levels. Change in CRP levels was statistically significant in subgroups of patients with high disease activity, CD and UC patients treated with a total dose of 500-1000mg iron, and patients who completed therapy. Amelioration of inflammatory activity as indicated by lower CRP levels was confirmed by reduced mean clinical disease activity indices (CDAI/CAI). Patients in both CRP subgroups showed increases in Hb, s-ferritin and TSAT, but reduced CRP levels and fewer symptoms. CONCLUSION(S): High-dosed FCM therapy does not appear to inhibit drug-induced amelioration of inflammatory activity in patients with IBD.

Relation between cadmium exposure and gestational diabetes mellitus

BackgroundCadmium (Cd) has been associated with type 2 diabetes in general population. However, the role of Cd in the occurrence of Gestational diabetes mellitus (GDM) remains unclear. ObjectivesOur study was aimed at investigating whether Cd exposure during pregnancy was associated with increased risk of GDM. MethodsCd concentrations were measured in urine samples from 6837 pregnant women in Wuhan, China, from 2012 to 2014. A “modified Poisson” model with a robust error variance was used to examine the association of GDM with continuous natural logarithm (ln) transformed urinary Cd or quartiles of urinary Cd levels. ResultsFor about 3-fold increase in Cd concentrations, there were 16% [relative risk (RR) =1.16; 95% confidence interval (CI): 1.03, 1.33] increase in risk of GDM. Compared with women in the lowest quartile of urinary Cd levels, women in the highest quartile had 1.30 higher risk of GDM [95% CI: 1.05, 1.61; p-trend <0.05]. Further analyses indicated overweight/obese women with higher urinary Cd levels had significantly higher risk of GDM, compared with women in the reference category of lowest quartile of Cd and normal pre-pregnancy body mass index [RR =2.71; 95% CI: 1.81, 4.07]. ConclusionsOur study presented a significantly positive association between urinary Cd levels and risk of GDM, supporting the hypothesis that environmental exposure to Cd may contribute to the development of GDM.

P086 Non-enzymatic serum antioxidant capacity is diminished in inflammatory bowel disease and is associated with severity of inflammation in ulcerative colitis

IBD results from activation of the gastrointestinal immune system toward gut microbiota in genetically susceptible individuals. Oxidative stress signalling plays a role in IBD development and exacerbation as it leads among others to mucosal barrier damage. Reduction of oxidative stress may preserve gut microbiota and control inflammation. We assessed the concentrations of free thiols (FT) and uric acid (SUA), constituting together a large part of non-enzymatic serum antioxidant capacity, with reference to IBD phenotype, activity, inflammatory markers, advanced oxydation protein products (AOPP) and as mucosal healing (MH) markers. A study group consisted of 175 individuals: 57 controls, 71 UC, and 47 CD patients. The disease activity was assessed using the Crohn's Disease Activity Index (CDAI) for CD and Rachmilewitz Index (RI) as well as Mayo Endoscopic Score for UC. SUA and FT concentrations were measured with uricase method and modified Ellman's method, respectively. As compared with controls, SUA concentrations were significantly lower in patients with CD but not UC. Detailed analysis demonstrated that SUA concentrations were significantly lower in both active CD and UC. In CD patients with active disease, SUA concentrations inversely correlated with CDAI (ρ = −0.35, p = 0.038). As compared with controls, FT concentrations were significantly lower in patients with both CD and UC, regardless the disease activity. There were no significant differences between CD and UC or patients with active and inactive disease. However, in CD and UC patients with active disease, FT concentrations were inversely correlated with, respectively, CDAI (ρ = −0.52, p = 0.001) and RI (ρ= −0.40, p = 0.044). In UC patients, SUA (ρ = −0.41, p < 0.001) and FA (ρ = −0.27, p = 0.023) concentrations were inversely correlated with the severity of bowel inflammation expressed in terms of Mayo endoscopic score with a significant drop between score 3 and scores 0 and 1. As MH markers, SUA displayed better overall accuracy, expressed in terms of area under ROC curve, and higher specificity than FA. Exclusively in patients with UC, SUA inversely but weakly correlated with IL-1 (ρ = −0.25, p = 0.035) and FT with TNF-α (ρ = −0.38, p = 0.044). In patients with active CD, FA was correlated with hsCRP (ρ = −0.56, p < 0.001), ESR (ρ = −0.51, p = 0.003), PLT (ρ = −0.45, p = 0.008), and IL-6 (ρ = −0.45, p = 0.008). Solely FT, in patients with active CD, inversely correlated with AOPP (ρ = −0.45, p = 0.007). Free thiol content, particularly in patients with active CD, was inversely related to various inflammatory markers as well as to AOPP, important marker of oxidative stress. Free thiol status and uric acid were decreased in IBD and correlated with severity of inflammation in UC.

Antioxidant enzyme activities of Folsomia candida and avoidance of soil metal contamination.

Induction of the antioxidant enzymes catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) and the avoidance of potentially toxic metals in soil by Folsomia candida were investigated. Both laboratory-spiked and field-polluted agricultural soils were used. Cadmium (Cd) concentrations in body tissues, animal avoidance behaviour and physico-chemical properties of the field soils were also determined. In laboratory Cd-spiked soils, the CAT and SOD activities in the Cd treatments were 71.1-94.7 and 1.31-4.55 times higher than in the control, respectively. In field-polluted agricultural soils, the CAT and POD activities generally increased with increasing pollution index (PI Nemerow ) of soil Cd, Cu, Pb and Zn. The CAT, POD and SOD activities at different PI Nemerow were 65.7-128, 30.1-180 and 36.5-95.8% higher than in the control, respectively. In line with the enzyme activities, Cd concentrations in the animal bodies were 8.31-15.1 and 3.21-10.0 times higher than in the control in spiked and field-polluted soils, respectively. Avoidance behaviour also increased with increasing metal concentrations in both soils. The effects of metals on CAT, POD or SOD activity were influenced by soil properties such as soil texture and pH. These results indicate that the antioxidant enzymes activities of F. candida can be induced by heavy metals and potentially used to assess the toxicity, and also that soil properties must be considered in the analysis of enzyme activities in different types of field soils.

Distribution and Health Risk Assessment of Heavy Metals in Atmospheric Particulate Matter and Dust

In order to study the concentration, distribution characteristics, and health risk assessment of toxic heavy metals, Cu, Mn, Pb, Ti, V, Cd, Cr, Co, Mo, and Ni, in atmospheric particulate matter (PM) and dust, the PM and dust samples were collected in all four seasons in 2014 in Beijing using two high volume air samplers (Echo Tecora Inc., Italy) and a dust tank, respectively. Selected metals were quantified by ICP-MS. Annual average concentrations of PM2.5 and PM10 were 153.40 μg·m-3 and 232.93 μg·m-3, which were five and three times higher than the Ambient Air Quality Standard values (GB 3095-2012), respectively. The average PM2.5/PM10 was 0.74, implying that PM2.5 predominated the particulate matter concentrations. The results of backward trajectory analysis suggested that exogenous particles originated from the northwest, north-northeast, southeast, and southeast-northwest during winter, spring, summer, and autumn, respectively. The order of annual average concentrations of selected metals in PM2.5 and PM10 was Ti > Mn > Pb > Cu > Cr > Ni > V > Cd > Mo > Co. The sum of the concentrations of Ti, Mn, Pb, Cu, and Cr accounted for 91.93% and 92.49% of the total concentration of target metals in PM2.5 and PM10, respectively. The metal content of dust followed the order of Ti > Mn > Pb > Cu > Ni > Cr > V > Co > Mo > Cd and Ti (2561.48 μg·g-1) accounted for 72.57% of the total metal content of dust. The geo-accumulation index (Igeo) of Cd, Pb, Cu, and Ni were 4.03, 2.49, 1.33, and 0.43, which represented the states of heavily to extremely contaminated, moderately to heavily contaminated, moderately contaminated and uncontaminated to moderately contaminated, respectively, indicating that dust in the target area included significant amounts of Cd, Pb, and Cu. The health risk assessment suggested that non-carcinogenic and carcinogenic risks of selected metals in PM10 and dust were within safe limits, but their long-term impact cannot be ignored.

Pollution characteristics, risk assessment, and source apportionment of heavy metals in road dust in Beijing, China

To analyze the spatial distribution patterns, risks, and sources of heavy metals (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn, Fe), 36 road dust samples were collected from an urbanized area of Beijing in June 2016. The mean concentration of most metals, except As and Mn, exceeded their corresponding background values, with the mean concentration of Cd being 8 times that of its background. Spatially, for most heavy metals, except As and Mn, the high concentration areas were mainly within the 5th ring road, especially the northern area. The geo-accumulation index of Cd and Cu indicated moderate contamination at many sites. The entire study area was prone to potential ecological risks, with higher risks within the 4th ring road. Cd caused high potential ecological risk at most sites. According to the health risk assessment results, the non-carcinogenic risks that human beings suffered from heavy metals were insignificant. However, the carcinogenic risks due to Ni and Cr exceeded the acceptable level. Based on the source apportionment using positive matrix factorization, four factors were defined for the heavy metals. Factor 1, which was traffic-related exhaust, accounted for 34.47% of the concentration of heavy metals. The contributions of Factors 2 and 3 were approximately 25% each. Factor 2 was potentially related to coal combustion, while Factor 3 could be related to the manufacture and use of metal components. Factor 4, which could be related to the use of pesticides, fertilizers, and medical devices, accounted for 14.88%, which was the lowest.

The Effect of Highway on Heavy Metal Accumulation in Soil in Turfy Swamps, Northeastern China

A detailed investigation was conducted to study the effect of highway on the accumulation of heavy metals in soils of turfy swamps. The concentrations of Cr, Zn, Cu, and Cd showed a decreasing trend with increasing distance from the road, while such trend was not identified in Pb, Ni, Co, and As. The results of factor analysis and cluster analysis indicated that Cr, Zn, Cu, and Cd were in a closer relationship than other metals and might be derived from common sources. The soil samples from JY and LQ sites with the highest traffic volume had the highest heavy metal concentrations of the three highways, while the concentrations of Cr and Cu were significantly positively correlated with traffic volumes (p < 0.05). Contamination levels of traffic-related metals were evaluated using the geo-accumulation index (I geo) and enrichment factor (EF) in turfy soil. The I geo index for Cr, Zn, Cu, and Cd varied from unpolluted to the heavily polluted, and the enrichment factor (EF) ranged from 0.44 (no enrichment) to 8.38 (significant enrichment) at JY and LQ site. For HSD site, the I geo index and EFs of Cr, Zn, and Cd in turfy soils were lower than that in JY and LQ, ranged from uncontaminated to moderate contamination and no enrichment to moderate enrichment, respectively. The I geo index and EFs of Cd were higher than 1 among all three sites. Therefore, Cd should be paid more attention to avoid potential risk to the flora and fauna in turfy swamps. The affected area of traffic-related metals was <30 m from the highway; this may be due to the abundant precipitation and long cold winter in Changbai Mountain area. The heavy metals could move with rainfall runoff and snowmelt in both particulate and dissolved forms.

Source Analysis, Spatial Distribution and Pollution Assessment of Heavy Metals in Sewage Irrigation Area Farmland Soils of Longkou City

Farmland soils in sewage irrigation area at Longkou City were collected, soil pH together with the heavy metal content were tested. Taking 70 soil points as the study object, this paper investigated the source of heavy metals in this area based on the correlation analysis and PCA of multivariate statistical analysis theory. We studied the spatial variation and distribution characteristics about heavy metals using both the theory of geostatistics and GIS spatial interpolation method. At last, the heavy metal pollution was evaluated in the way of Nemerow Index and improved fuzzy evaluation method. It turned out that, 9 kinds of heavy metal elements in the soil of research area had a certain degree of enrichment, among them the average of Cd was 3.06 times as high as the background value, and its enrichment was most severe. The result of Nemerow Index showed that, the values of comprehensive pollution index of Cu, Cd and Pb respectively were 7.06, 6.10 and 5.54, and they all belonged to high levels of pollution. According to the results of correlation analysis and principal component analysis, Cu, Zn together with Pb, Cd were mainly affected by human factors, sewage irrigation was their common pollution factor, the pollution sources for the first two heavy metals included excessive use of chemical fertilizers and pesticides in agricultural production and the accumulation of long time, whereas pollution from northern coal mining and coal gangue piled up as well as plating, machinery manufacturing and other industrial pollution were the pollution sources of the latter two elements. Other elements (Co, Cr, Mn, Ni and As) were mainly influenced by natural factors such as parent material. Comprehensive evaluation results showed that, among the 70 points, 13 points had moderate pollution,23 points belonged to light pollution, 28 points were at alert level, 6 points were in the safe range. From the perspective of spatial distribution,high value areas of heavy metal contents were mainly concentrated in towns of Zhuyouguan and Xufu. This showed that, sewage irrigation caused a certain degree of heavy metal pollution to local soil.

Comprehensive Risk Evaluation of Cadmium in Soil-rice System Based on Uncertainty Analysis

Cadmium (Cd) can cause adverse health effects and is a subject of concern in rice consumption. The uncertainty analysis helps improve the accuracy in the risk assessment for Cd in soil-rice system. A regional investigation on Youxian prefecture, southern China, was conducted to analyze the Cd concentration in rice. Based on the species sensitivity distribution model (SSD), health risk assessment model, and Monte Carlo simulation, the accumulation characteristic of Cd in soil-rice system, accumulation risk of Cd in soil, and health risk of Cd concentration in rice were determined. The results showed that the plant uptake factor (PUF) of Cd of rice was well fitted by the SSD model. The mean level of PUF was 1.86, with a significant spatial heterogeneity. The rice produced in WL county tended to accumulate a high level of Cd. There was no significant relationship between concentrations of Cd in soil and rice, suggesting that of rice renders the Cd risk management very difficult. The pollution load index of Cd in soil was 2.4, which belonged to a moderate contamination level. Under current accumulation condition of Cd in soil, there would be a 90.4% probability for soil Cd concentration to be higher than the national soil quality standard after 10 years. Health risk assessment showed that the average daily dose (ADD) was 2.9 μg·(kg·d)-1, 3.5 fold higher than the WHO limit. About 93.9% of the adult populations consuming rice cropping in affected areas had the risk that the daily Cd intake was above the WHO limit. The health risk index (HRI) was around 2.1 to 4.7. The probability for health risk index (HRI) higher than 5 was 21.5%, suggesting a high health risk. When the soil pH was lower than 5.5, the probability for HRI higher than 1 was 95.3%, and when the soil pH was higher than 6, the probability for HRI higher than 1 reduced to 68.1%. An improved management of soil pH values would be needed for a better and safer rice production. The combination of uncertainty analysis, species sensitivity model and health risk assessment model was validated to be feasible and reliable in the risk analysis.

Combining contamination indexes, sediment quality guidelines and multivariate data analysis for metal pollution assessment in marine sediments of Cienfuegos Bay, Cuba

The purpose of the present work was to combine several tools for assessing metal pollution in marine sediments from Cienfuegos Bay. Fourteen surface sediments collected in 2013 were evaluated. Concentrations of As, Cu, Ni, Zn and V decreased respect to those previous reported. The metal contamination was spatially distributed in the north and south parts of the bay. According to the contamination factor (CF) enrichment factor (EF) and index of geoaccumulation (Igeo), Cd and Cu were classified in that order as the most contaminated elements in most sediment. Comparison of the total metal concentrations with the threshold (TELs) and probable (PELs) effect levels in sediment quality guidelines suggested a more worrisome situation for Cu, of which concentrations were occasional associated with adverse biological effects in thirteen sediments, followed by Ni in nine sediments; while adverse effects were rarely associated with Cd. Probably, Cu could be considered as the most dangerous in the whole bay because it was classified in the high contamination levels by all indexes and, simultaneously, associated to occasional adverse effects in most samples. Despite the bioavailability was partially evaluated with the HCl method, the low extraction of Ni (<3% in all samples) and Cu (<55%, except sample 3) and the relative high extraction of Cd (50% or more, except sample 14) could be considered as an attenuating (Ni and Cu) or increasing (Cd) factor in the risk assessment of those element.

Occurrences and toxicological risk assessment of eight heavy metals in agricultural soils from Kenya, Eastern Africa.

The concentration distribution and toxicological assessment of eight heavy metals including lead (Pb), cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), mercury (Hg), arsenic (As), and zinc (Zn) in agricultural soils from Kenya, Eastern Africa, were investigated in this study. The results showed mean concentrations of eight heavy metals of Zn, Pb, Cr, Cu, As, Ni, Hg, and Cd in agricultural soils as 247.39, 26.87, 59.69, 88.59, 8.93, 12.56, 8.06, and 0.42mgkg(-1), respectively. These mean values of eight heavy metals were close to the toxicity threshold limit of USEPA standard values of agricultural soils, indicating potential toxicological risk to the food chain. Pollution index values revealed that eight heavy metals severely decreased in the order Hg > Cd > As > Cu > Pb > Zn > Ni > Cr and the mean value of the overall pollution index of Hg and Cd was 20.31, indicating severe agriculture ecological risk. Potential pollution sources of eight heavy metals in agricultural soils were mainly from anthropogenic activities and natural dissolution. The intensification of human agricultural activities, the growing industrialization, and the rapid urbanization largely influenced the concentration levels of heavy metals in Kenya, Eastern Africa. Moreover, the lack of agricultural normalization management and poor enforcement of environmental laws and regulations further intensified the widespread pollution of agricultural soils in Kenya.

Spatial distribution and pollution assessment of heavy metals in the surface sediments of the Bohai and Yellow Seas

A total of 141 surface sediments were collected and analyzed for their geochemistry, total organic carbon, and grain size to assess the heavy metal pollution in the Bohai and Yellow Seas. The enrichment factor (EF) and geoaccumulation index (Igeo) of Cu, Pb, Zn, Cr, Cd, Ni, As, and Hg were calculated to assess anthropogenic contamination, and the results suggest that moderate Pb, Cd, and As contamination occurs in the study area. Sediment quality guidelines were applied to assess the adverse biological effects of these metals. The spatial distribution of the mean Effects Range-Median quotient for the vast majority of the study area is between 0.1 and 0.5, indicating low impact and potential negative biological effects. Multivariate analysis indicates that Cu, Pb, Zn, Cr, and Ni resulted primarily from lithogenic sources, whereas As, Cd, and Hg were mainly attributed to anthropogenic sources.

Assessment of health risk of trace metal pollution in surface soil and road dust from e-waste recycling area in China

Informal recycling of e-waste and the resulting heavy metal pollution has become a serious burden on the ecosystem in Guiyu, China. In this investigation, we evaluated the trace metal concentration of community soil and road dust samples from 11 locations in Guiyu and 5 locations (consisting of residential areas, kindergarten/school, and farm field) in a reference area using graphite furnace atomic absorption spectrophotometer. The study spanned four seasons, 2012-2013, with a view to assess the risk associated with e-waste recycling in the study area. The concentrations of Pb, Cd, Cr, and Mn were 448.73, 0.71, 63.90, and 806.54mg/kg in Guiyu soil and 589.74, 1.94, 69.71, and 693.74mg/kg, in the dust, respectively. Pb and Cd values were significantly higher (P ≤ 0.05) than the reference area, and the mixed model analysis with repeated seasonal measurements revealed soil Pb and Cd levels that were 2.32 and 4.34 times, while the ratios for dust sample were 4.10 and 3.18 times higher than the reference area. Contamination factor, degree of contamination, and pollution load index indicated that all sampling points had a high level of metal contamination except farm land and kindergarten compound. The cumulative hazard index of Pb, Cd, Cr, and Mn for children in exposed area was 0.99 and 1.62 for soil and dust, respectively, suggesting non-cancer health risk potential. The significant accumulation of trace metals in the e-waste recycling area predisposes human life, especially children, to a potentially serious health risk.