Health risk assessment of heavy metal pollution in groundwater of a karst basin,SW China

To investigate the presence of metal elements and assess their health risk for the populace in the Nandong Underground River Basin(NURB),we conducted an analysis of eleven common heavy metals in the water body.A Health risk assessment(HRA)model was employed to analyze 84 water samples from the NURB.The detection results revealed the following order of heavy metals concentrations:Fe>Al>Mn>Zn>As>Cd>Pb>Cr>Ni>Cu>Hg.Correlation analysis indicated a certain similarity in material source and migration transformation among these eleven metal elements.Our study identified that the health risks for local residents exposed to metal elements in the water of NURB primarily stem from carcinogenic risk(10^(−6)–10^(−4)a^(−1))through the drinking water pathway.Moreover,the health risk of heavy metal exposure for children through drinking water was notably higher than for adults.The maximum health risks of Cr in both underground and surface water exceeded the recommendation standard(5.0×10^(−5)a^(−1))from ICRP,surpassing the values recommended by the Swedish Environmental Protection Agency,the Dutch Ministry of Construction and Environment and the British Royal Society(5.0×10^(−6)a^(−1)).The results of the health risk assessment indicate that Cr in the water of NURB is the primary source of carcinogenic risk for local residents,followed by Cd and As.Consequently,it is imperative to control these three carcinogenic metals when the water was used as drinking water resource.

The Determination of Heavy Metal Elements in Sipunculs nudus by MWD-ICP-AES

In order to develop a method for measuring of elements in Sipunculus nudus, the contents of Cu, Pb, Cd, Cr, Mn, As, Hg and Ba were determined by actively coupled plasma atomic emission spectrometry （MWD） and microwave digestion （ICP-AES）. The results showed that correlation coefficients al kept higher than 0.999 and the recovery rates of sample added standard solutions were in 98%-114%. The results indicated that the contents of Cu, Pb, Cd, Cr, Mn, As, Hg and Ba were 17.119, 3.781, 0.695, 7.351, 1997.982, 0.620, 0.144, 4.249 mg/kg respectively. The contents of Mn exceeded national limit by hundredfold, Cd sevenfold, Pd fourfold, Cd three-and-a-half-fold, and As onefold. Sipunculs nudus became seriously pol uted. Therefore, it is necessary to formulate robust policies to fol ow closely and pay close attention to coastal areas pol ution around Dongfang City.

Effects of Alloying Elements on the Microstructures and Mechanical Properties of Heavy Section Ductile Cast Iron

The effects of alloying elements on the as-cast microstructures and mechanical properties of heavy section ductile cast iron were investigated to develop press die material having high strength and high ductility. Measurements of ultimate tensile strength, 0.2% proof strength, elongation and unnotched Charpy impact energy are presented as a function of alloy amounts within 0.25 to 0.75 wt pct range. Hardness is measured on the broken tensile specimens. The small additions of Mo, Cu, Ni and Cr changed the as-cast mechanical properties owing to the different as-cast matrix microstructures. The ferrite matrix of Mo and Ni alloyed cast iron exhibits low strength and hardness as well as high elongation and impact energy. The increase in Mo and Ni contents developed some fractions of pearlite structures near the austenite eutectic cell boundaries, which caused the elongation and impact energy to drop in a small range. Adding Cu and Cr elements rapidly changed the ferrite matrix into pearlite matrix, so strength and hardness were significantly increased. As more Mo and Cr were added, the size and fraction of primary carbides in the eutectic cell boundaries increased through the segregation of these elements into the intercellular boundaries.

Determination of wholesome elements and heavy metals in safflower(Carthamus tinctorius L.)from Xinjiang and Henan by ICP-MS/ICP-AES

An inductively coupled plasma mass spectrometry （ICP-MS） or inductively coupled plasma atomic emission spectrometry （ICP-AES） was developed to determine 19 elements in safflower, a traditional Chinese medicinal herb from Xinjiang Autonomous Region and Henan Province of China. Totally 19 elements in safflower included heavy metals, i.e. As, Cd, Cu, Hg and Pb, and wholesome elements, i.e. Al, Ca, Co, Cr, Fe, Mg, Mn, Mo, Ni, P, Se, Sr, V and Zn. The results showed that the concentrations of heavy metals in safflower samples were both low, all of which met the national hygiene standards except for Pb in Xinjiang sample. Meanwhile, the distribution tendency of elements in the two samples was similar, which indicated that the plant might absorb given elements in a proportional way. The method can be used for the quality control of elements in safflower, and it provides a way for the determination of the contents of safflower from Xinjiang and Henan.

Heavy Metal Control in Domestic Rubbish by Source Screening and Suitability of Nutrient Elements as Turfgrass Medium

This paper, probing into heavy metal control in domestic rubbish by source screening and nutrient element analysis, revealed the feasibility of source control of heavy metals and the suitability of rubbish as turfgrass medium. Heavy metals in domestic rubbish were controlled by source screening before composting. The study consisted of a control with garden soil. The contents of main mineral elements and heavy metals in rubbish compost and control were determined by the method of ICP-AES. The results showed that heavy metal concentrations in rubbish were lower than those in garden soil, and little difference occurred between rubbish and garden soil in main mineral element concentrations. Based on this, it was concluded that rubbish compost was favorable for using as turfgrass medium and heavy metal control in rubbish by source screening was effective.

SPATIAL-TEMPORAL VARIATION OF HEAVY METAL ELEMENTS CONTENT IN COVERING SOIL OF RECLAMATION AREA IN FUSHUN COAL MINE

Grid method is employed for sampling covering soil at the test field,whic h is reclamation area filled by coal mining wastes for cropland in th e Fushun coal mine,Liaoning Province,the Northeast China.The soil samp les are taken at different locations,inclu ding three kinds of covering soil,th ree different depths of soil layers a nd four different covering ages of covering soil.The s patial-temporal variation of heavy metal element content in reclamatio n soil is stud-ied.The results indicate that the co ntent of heavy metal elements is decreasing year after year;the determin ant reason why the content of heavy metal elemen ts at 60cm depth layer is higher than t hat at 30cm depth layer and surface is fertiliz-er and manure application;the metal elements mainly come from external environment;there is no metal pollut ion coming from mother material(coal mining wastes)in plough layer of covering soil.

Effect of occurrence mode of heavy metal elements in a low rank coal on volatility during pyrolysis

The harmful trace elements will be released during coal utilization, which can cause environment pollution and further endangering human health, especially for heavy metal elements. Compared to combustion, the release of heavy metal elements during coal pyrolysis process, as a critical initial reaction stage of combustion, has not received sufficient attention. In the present paper, a low rank coal, from Xinjiang province in China, was pyrolyzed in a fixed bed reactor from room temperature, at atmospheric pressure, with the heating rate of 10 °C/min, and the final pyrolysis temperature was from 400 to 800℃ with the interval of 100℃. The volatility of heavy metal elements (including As, Hg, Cd and Pb) during pyrolysis process was investigated. The results showed the volatility of all heavy metal elements increased obviously with increasing temperature, and followed the sequence as Hg > Cd > As > Pb, which was mainly caused by their thermodynamic property and occurrence modes in coal. The occurrence modes of heavy metals were studied by sink-andfloat test and sequential chemical extraction procedure, and it can be found that the heavy metal elements were mainly in the organic and residual states (clay minerals) in the raw coal. And most of the organic heavy metals escaped during the pyrolysis process, the remaining elements were mainly in the residual state, and the elements in Fe-Mn state also tended to remain in the char.

Origin of Shallow Jurassic Heavy Oils in the Northwestern Margin of the Junggar Basin,NW China:Constraints from Molecular,Isotopic and Elemental Geochemistry

Oil group separation,gas chromatography-mass spectrometry analysis of saturated hydrocarbons,carbon isotope analysis of fractions and tests on trace elements were all carried out to determine the origin of shallow Jurassic heavy oils in the northwestern margin of the Junggar Basin,northwestern China.Results showed that all the crude oils had been subjected to different degrees of biodegradation,on an order ranging from PM 6 to 9,which yielded many unresolved complex mixtures(UCM)and formed a huge spike in the mass chromatogram(M/Z=85).Two heavy oils from the Karamay area underwent slight biodegradation,characterized by the consistent ratios of biomarker parameters.C_(21)/C_(23)and C_(23)/H of the two samples were 0.81 and 0.85,while G/H,C_(27)/C_(29)and C_(28)/C_(29)were 0.38 and 0.40,0.16 and 0.27,0.87 and 0.86,respectively.The isomerization parameters of terpane and steranes were 0.50-0.53,and 0.48-0.49,respectively.The above geochemical indices indicated that the crude oils in the study area were in the marginally mature stage.The parent materials were a mixture,consisting of bacteria,algae and some higher plants,formed under reducing depositional conditions,which is in agreement with the source rocks of the Fengcheng Formation in the Mahu depression.The carbon isotopic compositions of saturated hydrocarbon,aromatic hydrocarbon,NSO and asphaltene were−31‰−to−30.3‰,−29.5‰to−29.03‰,−29.4‰to−28.78‰and−28.62‰to−28.61‰,respectively.These findings are in agreement with the light carbon isotope of kerogen from the lower Permian Fengcheng Formation.Furthermore,V/Ni and Cr/Mo of all the crude oils were 0.01 to 0.032,0.837 to 10.649,which is in good agreement with the ratios of the corresponding elements of the extracts from the Fengcheng Fm.carbonate source rock.As a result,a two-stage formation model was established:(1)the oil generated from the carbonate source rocks of the Fengcheng Formation migrated to the Carboniferous,Permian and Triassic traps during the Late Triassic,forming the primary oil reservoirs;(2)during the Late Jurassic period,the intense tectonic activity of Yanshan Episode II resulted in the readjustment of early deep primary reservoirs,the escaped oils gradually migrating to the shallow Jurassic reservoir through cross-cutting faults,unconformities and sand body layers.The oils then finally formed secondary heavy oil reservoirs,due to long-term biodegradation in the later stage.Therefore,joint methods of organic,isotopic and element geochemistry should be extensively applied in order to confirm the source of biodegradation oils.

Monitoring the Heavy Element of Cr in Agricultural Soils Using a Mobile Laser-Induced Breakdown Spectroscopy System with Support Vector Machine

Due to its complicated matrix effects, rapid quantitative analysis of chromium in agricultural soils is difficult without the concentration gradient samples by laser-induced breakdown spectroscopy. To improve the analysis speed and accuracy, two calibration models are built with the support vector machine method： one considering the whole spectra and the other based on the segmental spectra input. Considering the results of the multiple linear regression analysis, three segmental spectra are chosen as the input variables of the support vector regression （SVR） model. Compared with the results of the SVR model with the whole spectra input, the relative standard error of prediction is reduced from 3.18% to 2.61% and the running time is saved due to the decrease in the number of input variables, showing the robustness in rapid soil analysis without the concentration gradient samples.

Investigating Catalase and Carbonic Anhydrase Enzyme Activities and Levels of Certain Trace Elements and Heavy Metals in Patients with Primary and Metastatic Hepatic Carcinoma

Hepatocellular carcinoma (HCC) is among most common terminal cancer types in the world. Primary etiological factors include cirrhosis, hepatitis, aflatoxin and alcohol. The current study was conducted to determine cytosolic erythrocyte carbonic anhydrase and catalase enzyme activities and levels of some trace elements. For this purpose, 40 patients with primary and metastatic hepatic cancer and 29 healthy volunteers enrolled to the study. Catalase and carbonic anhydrase enzyme activities and serum trace element levels were measured in patient and control groups. In the current study, serum copper, magnesium, manganese and zinc levels were lower in the primary and metastatic hepatic cancer group in comparison with the control group (P < 0.05). In contrast, serum iron, cobalt, cadmium and lead levels were higher in the patient relative to the control group (P < 0.05). In comparison with the control group, the catalase level was lower in primary and metastatic cancer group, while the carbonic anhydrase level was higher in the cancer group (P < 0.05). Changes in levels of trace elements and anti-oxidant enzymes may be the factors which influence the development and progression of liver cancer. The carbonic anhydrase enzyme can be a useful indicator in the diagnosis of cancer. However, this issue warrants further investigation.

Migration of Heavy Metal Elements in Reclaimed Irrigation Water-Soil-Plant System and Potential Risk to Human Health

[Objectives]To study the impact of heavy metal pollution of soil and plants during the process of reclaimed water for irrigation of green land in arid areas and the potential health risks to humans during use.[Methods]Taking Zhongwei City in Ningxia,a typical arid area,as the research area,the irrigation water,soil and green grass in the reclaimed water irrigation region and the original green water irrigation region were sampled,the heavy elements Hg,As,Zn,Pb,Cd,Cr were detected,and the Nemerow method,biological absorption coefficient,and health risk assessment were employed to evaluate the degree of soil pollution,plant absorption capacity,and human health risks.[Results]Compared with the original green water,the Hg,Cd,and Cr pollution of the reclaimed water irrigated green land was higher,the As,Zn,Pb pollution was lower,and the content of Hg and Cd was higher than the environmental background values of soil in Ningxia;the Cr content exceeded the risk intervention values of the first type of land in the Soil Environmental Quality—Risk Control Standard for Soil Contamination of Development Land(GB 36600-2018).Compared with the original green water irrigation region,it is found that the reclaimed water irrigation reduced the heavy metal pollution of the soil to a certain extent.The heavy metal content of tall fescue grass(Festuca arundinacea)in the reclaimed water irrigation region was Zn,Cr,Pb,As,Cd,and Hg from high to low;the order of the biological absorption coefficient was Cd>As>Zn>Pb>Hg>Cr;irrigation water exerted a certain effect on the content of heavy metals in plants and the biological absorption coefficient through the soil.Using the health risk assessment method recommended by Environmental Protection Agency of the United States of America(USEPA),it was found that the reclaimed water has the highest risk through the inhalation route,and the occupational population has a higher risk of skin contact with soil and plants.[Conclusions]This study is intended to provide data support and theoretical basis for the environmental safety risk research of the application of reclaimed water in arid areas to urban greening.

Evaluation on environmental quality for heavy metal elements of Xihe soil

According to "Environmental quality standard for soil" and using As,Cd,Cr,Cu,Hg,Ni,Pb,Zn elements as evaluation index,the author evaluated soil environmental quality in Xihe area of Shenyang.The results show that the soil in Xihe area is polluted rifely by heavy metal elements.The polluted areas are mainly distributed near the upstreams of Xihe River,Shenxin River and Shenliao irrigation canal.There exist large distinctions among the heavy metal elements to the pollution degree.Cd pollution area is the biggest and the most serious in pollution degree.

Plasma Concentrations of Some Trace Element and Heavy Metals in Patients with Metastatic Colon Cancer

Purpose: It is well known that trace elements and heavy metals play a significant role in human health and disease. These elements play an important role in different metabolic pathways of cells and tissues. Trace element deficiency or excess is implicated in the development or progression of some cancers. We present a study which investigates serum/ plasma levels of trace-heavy elements in metastatic colon cancer patients and healthy subjects. Methods: Blood samples were collected from 29 healthy subjects and 40 patients with metastatic colon cancer in Oncology Department of Medical School of Yuzuncu Yil University. In both groups, the serum levels of copper (Cu), magnesium (Mg), lead (Pb), chromium (Cr), zinc (Zn) selenium (Se), manganese (Mn), and cadmium (Cd) were determined. Results: Higher levels of Cu, Mg, Pb, Cr, Zn, Mn and Cd were seen in patients with metastatic colon cancer compared to healthy subjects and these findings were statistically significant (p 0.05). Se levels were noted to be lower in patients with colon cancer in comparison to healthy subjects and this finding was also statistically significant (p 0.05). Conclusions: According to our findings there was significant diffence in trace elements and heavy metals levels between healthy subjects and metastatic colon cancer patients. Therefore heavy metal and trace elements may have prognostic significance in complex disorders including colon cancer. However, further comprehensive studies are needed in order to advance our understanding of the relationship between heavy metal and trace elements and their role in cancers.

Heavy metal pollution assessment in marine sediments in the Northwest coast of Sabah,Malaysia

Heavy metal contents along the Northwest coast of Sabah were determined to interpret the pollution level in the marine sediment. The metal abundance is regulated by the physico-chemical properties such as the average sediment pH(7.82, 9.00 and 8.99), organic matter(0.62%, 1.60%, and 2.27%), moisture content(25.00%, 29.70%, and 15.00%) and sandy texture in Kota Belud, Kudat and Mantanani Island,respectively. The major elements show Ca>Fe>Mg>Al>Mn for all study sites, while the heavy metals show Ni>Cr>Zn>Cu>Co>Pb, Cr>Ni>Zn>Cu>Pb>Co and Zn>Pb>Cr>Ni, for Kota Belud, Kudat and Mantanani Island, respectively. The pollution degree of heavy metals was evaluated by using the Sediment Quality Assessment(SQA). The SQA parameters indicated none to moderate pollution in Kota Belud that shows Class 0, Class 1 and Class 2 pollution. The parameters also indicated none to low pollution in Kudat and Mantanani Island that show only Class 0 pollution. The enrichment factor(EF) suggested minor to moderately severe metal enrichment by anthropogenic sources in Kota Belud, whereas only minor enrichment in Kudat and Mantanani Island. The modified pollution degree(MCD<1.5) and pollution load index(0 PLI<1) indicating only low pollution level in the marine sediments for all study sites. The objectives of this study are:(1) to determine the physico-chemical parameters of sediments,(2) interpret the heavy metal contents and(3) evaluate the sediment quality.

Analysis of Wholesome Elements and Heavy Metals in Red Soybean by Inductively Coupled Plasma Mass Spectrometry

Objective: To study wholesome elements and heavy metals in red soybean of Heilongjiang Province. Methods: Samples preparation with hydrodigestion, and twenty-four elements quantitative analysis in red soybean by inductively coupled plasma mass spectrometry technique (ICP-MS) with indium, platinum, ruthenium as internal standard. Results: The red soybean contained many elements necessary to human health, the sequence of elements (higher than mg/kg) was K > Mg > Ca > Fe ≈ Zn > Na > Mn > Ti > Cu > Sr ≈ Ni > Ba > Mo. Besides the trace elements, the contents of heavy metals were very low than National standard. With reference standard substance and added standard recovery for the quality control of analytical method, the results were credibility, recovery 85% - 114%, the detect limit 0.2 - 20 ng/g, linearity range 0 - 200 μg/g (r > 0.999), RSD (n = 6) Conclusion: The established method could be applied to the element quantitative analysis in food, simple and high sensitivity.

Selective Separation of Light and Heavy Rare Earth Elements from the Pregnant Leach Solution of Apatite Ore with D2EHPA

Different separation techniques such as solvent extraction, ion exchange, and precipitation are often used for recovery of rare earth elements (REEs) from pregnant leach solutions obtained from acid leaching. Solvent extraction is generally accepted as the most appropriate commercial technology for separating REEs due to the need to be able to handle larger volumes of diluted pregnant solutions. This study focused on the development of selective separation of light and heavy REEs from the pregnant leach solution obtained from leaching of apatite ore in 1 M sulfuric acid (H2SO4) using solvent extraction. Three different commercial organophosphorus extractants (di-(2-ethylhexyl) phosphoric acid (D2EHPA), 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC88A) and tributyl phosphate (TBP)), and the influences of experimental parameters such as extractant concentration, organic/aqueous phase ratio, diluent type, pH, extraction time and stripping agent concentration were examined. Results showed that light REEs (LREEs) and heavy REEs (HREEs) in the pregnant leach solution were selectively separated with D2EHPA via a two-stage extraction process. In the first-stage of solvent extraction, >90% of (0.05 g/L) HREEs was extracted with 1.8 M D2EHPA in kerosene while the vast majority (>95%) of LREEs was remained in raffinate. In the second-stage, >93% (1.01 g/L) of LREEs was extracted from the raffinate with 1.8 M D2EHPA dissolved in kerosene at pH 1.6. HREEs (>95%) and LREEs (>90%) loaded with D2EHPA after the first and second-stage of extraction were stripped by 4 M H2SO4 and 1 M H2SO4 solutions, respectively. Distribution of middle rare earth elements (MREEs) was discussed through the extraction processes in this study.

Gross alpha and beta activities and trace heavy elemental concentration levels in chemical fertilizers and agricultural farm soils in Nigeria

The gross alpha (α) and beta (β) activities and trace heavy elemental concentrations have been determined in Single Super Phosphate (SSP) and Nitrogen Phosphorous Potassium (NPK) fertilizers samples used for agricultural purposes in Nigeria. Cultivated farm soil samples from two regions (north and south) in the country and samples of phosphate rocks were also analyzed for gross α and β radioactivity and elemental concentrations. The beta activity concentration in the NPK (15-15-15) fertilizers was found to vary from 2410.0 ± 80.0 Bq·kg–1 to 4560 ± 140.0 Bq·kg–1, between 1340.0 ± 70.0 Bq·kg–1 and 1440.0 ± 70.0 Bq·kg–1 in the Single Super phosphate fertilizers while in the farm soil it ranged between 360.0 ± 40.0 Bq·kg–1 to 570.0 ± 50.0 for the north samples and 200.0 ± 50.0 to 230.0 ± 20 Bq·kg–1 for the south samples. The alpha activities in the NPK fertilizers was found to vary from 20.0 ± 10.0 to 90.0 ± 20.0 Bq·kg–1, in the SSP it varied from 60.0 ± 20.0 to 100.0 ± 20.0 Bq·kg–1 while in the soil samples it varied from 8.0 ± 6.0 to 40.0 ± 10.0

MATHEMATICAL STATISTICS OF HEAVY MINERALS AND THEIR REE AND TRACE ELEMENTS IN THE NORTHWESTERN SEA AREA OF ANTARCTIC PENINSULA

Based on the analysis and mathematical statistics of quantitative data on both the heavy minerals and their REE (La, Ce, Nd, Sm, Eu, Tb, Yb, Lu), trace (Zr, Hf, Th, Ta, U, Rb, Sr, Zn, Co, Ni, Cr, As, Sc) and major (Fe) elements in the surface sediments in the northwestern sea area of Antarctic Peninsula, the authors find that the heavy minerals as the carriers of REE and trace elements should not be overlooked.Q-mode factor analysis of the heavy minerals provides a 3-factor model of the heavy mineral assemblages in the study area, which is mainly controlled by the origin of materials and sea currents. The common factor P1, composed mainly of pyroxene and metal minerals, and common factor P2, composed of hornblende, epidote and accessory minerals, represent two heavy mineral assemblages which are different from each other in both lithological characters and origin of materials. And common factor P3 probably results from mixing of two end members of the above-mentioned assemblages. R-mode group analysis of the heavy minerals indicates that there are two heavy mineral groups in the sea area, which are different from each other in both genesis and origin of materials. With the help of R-mode analysis, 22 elements are divided into 3 groups and 9 subgroups. These element assemblages show that they are genetically related and that they are different in geochemical behaviors during diagenesis and mineral-forming process. In addition, the relationship between the heavy mineral assemblages and the element subgroups is also discussed.

Annual Fluxes of Heavy Metal Elements in Atmospheric Dry and Wet Depositions in the Pearl River Delta Economic Region, Guangdong Province

There are 158 sampling points to be set up in the Pearl River delta economic region. The collecting period is mostly one year, namely, from July 2007 to July 2008. The eight heavy metal elements of Cr, Ni, Cu, Pb, Zn, As, Hg, and Cd in 474 dry and wet deposition samples were tested in terms of the standard procedures. Their average annual fluxes have no obvious difference between dry deposition and wet deposition. So these elements might be at an equilibrium or quasi-equilibrium state between dry deposition and wet deposition.

Grain refinement of W-Ni-Fe heavy alloys by tantalum element adding

90W-7Ni-3Fe and (90-x)W-xTa-7Ni-3Fe (x=1,3,5,7,10) specimens were attained by liquid phase sintering. A model describing the process of liquid forming and spreading was proposed to point out the differences between alloys doped with tantalum and traditional tungsten heavy alloys. Tantalum priority of entering matrix and a relative high solubility in liquid matrix depress tungsten solubility in liquid matrix, which decreases kinetic rate constant K and consequently results in the reduction of W grain size. The grain refinement is influenced by Ta content and becomes more obvious when Ta content is over 5%. The sample with less than 3%Ta has dominant W and matrix phases. While besides W and matrix phases, intermetallic phases emerge in 85W-5Tai-7Ni-3Fe sample. Ta is superfluous and forms a new tantalum phase when more than 7% Ta is added into alloys.