Review Study on the Accumulation and Release of Trace Metal Elements on Aluminum Containing Sediments in Drinking Water Distribution System

Accumulation and releasing of trace metal elements on aluminum containing sediments of inner drinking water pipe is discussed,as studied from five variations effecting:raw water quality,chemical reagents,solution pH and drinking water flow condition.In order to decrease the release of trace metal elements,and to ensure the pipe operation and human safety,water quality adjustment is suggested to avoid aluminum containing sediments formation in drinking distribution system.The maximum amounts of accumulation of common trace metal elements are given.Future trends of development in this field are also proposed.

Contents of Trace Metal Elements in Cow Milk Impacted by Different Feedstuffs

Feedstuff intake plays key role in impacting the yield and quality of milk. In this study, we discussed the contents of trace metal elements in cow milk impacted by different feedstuffs. We detected the contents of Pb, Cd, As, Cu, Mg, Ca, Fe and Zn in different feedstuffs and milk by atomic absorption spectrophotometry. The determinations of Pb, Cd and As contents were by graphite furnace A_AS and Cu, Mg, Ca, Fe and Zn was by flame atomic absorption spectrometry. The results showed that Pb, Cd, As and Cu presented in feedstuffs, but Pb, Cd and As were lowly detected in milk samples, and Cu was not detected in milk samples. The content of Mg in concentrates was lower than that in forages. However, the content of Mg in milk from concentrate feed was higher than that in forage feed. This suggested that the utilization of Mg in concentrate feed was higher than that in forage feed. The contents of Ca and Zn were opposite to Mg, and the utilization of Ca and Zn in forage feed was higher than that in concentrate feed. There was no obviously change law of Fe in different feedstuffs and milk samples. The relationship between the contents of trace metal elements in milk to feedstuffs would provide a theoretical basis for dairy farming. It would be useful for improving the milk yield and milk quality of dairy production.

Retention Factors for Trace Metal Elements in Solid Phase and Applicable Adsorption Models: Case of <i>Moringa oleifera</i>

Moringa oleifera is an edible plant cultivated throughout the tropical belt. It belongs to the family Moringaceae and is one of its 14 known species. This paper presents a synthesis of the main factors responsible for the retention of trace metal elements (TMEs) by Moringa oleifera seed powder, a natural adsorbent. The five main factors studied are metal concentration, solution pH, adsorbent particle size, adsorbent dose and adsorbent/adsorbate contact time. Through these factors, we present the optimal conditions for removal of these TMEs, as well as adsorption isotherm models appropriate for the conditions of retention of these metal cations by the adsorbent. The times of 20 min (GD) and 50 min (GND) are the equilibrium times obtained in our study. An optimal adsorbent mass (GD and GND powders) of 4.5 g was found. 20% to 97% abatement is observed for average pH values between 6 and 8. The coefficients of determination (R2) obtained (0.972, 0.963, 0.991 and 0.799) during the isotherm experiments carried out at 20°C, 30°C, 40°C and 50°C are close to 1. Also, the separation factor (RL), an essential characteristic of the Langmuir isotherm whose values are between 0 and 1, attest to the applicability of the Langmuir isotherm model to fit the experimental data of copper adsorption by Moringa powders. In this paper, we are particularly interested in the following TMEs (Mn, Ni, Cr, Cu, Cd, Co, Pb, Fe, Zn, Ag).

Trace metal elements: a bridge between host and intestinal microorganisms

Trace metal elements, such as iron, copper, manganese, and zinc, are essential nutrients for biological processes. Although their intake demand is low, they play a crucial role in cell homeostasis as the cofactors of various enzymes. Symbiotic intestinal microorganisms compete with their host for the use of trace metal elements. Moreover, the metabolic processes of trace metal elements in the host and microorganisms affect the organism's health. Supplementation or the lack of trace metal elements in the host can change the intestinal microbial community structure and function. Functional changes in symbiotic microorganisms can affect the host's metabolism of trace metal elements. In this review, we discuss the absorption and transport processes of trace metal elements in the host and symbiotic microorganisms and the effects of dynamic changes in the levels of trace metal elements on the intestinal microbial community structure. We also highlight the participation of trace metal elements as enzyme cofactors in the host immune process. Our findings indicate that the host uses metal nutrition immunity or metal poisoning to resist pathogens and improve immunity.

Predictive Study of Trace Metal Pollution of Gold Panning Sites in Birimian Formations: Case of the Yaouré Furrow (Côte d’Ivoire)

The present study was carried out on small-scale gold mining sites in the Yaouré region of Côte d’Ivoire. This region is geologically representative of the Birimian formations (2.1 Ga) of West Africa. The aim is to determine the potentially toxic trace metals (TMEs) generated by these sites, with a view to preventing possible contamination and/or metal pollution of the waters that provide fish products for local populations. To this end, a sampling campaign was carried out, resulting in the collection of 20 mining waste samples analyzed by X-ray fluorescence spectrometry (XRF) and 10 by X-ray diffractometer (XRD). The XRF analysis detected 06 predominant TMEs: arsenic, chromium, copper, nickel, zinc and vanadium. Statistical analysis was carried out to determine the distributions and correlations between these ETMs. To assess contamination and/or pollution levels, the following indices were calculated on the basis of reference concentrations of upper continental crust MTEs: Enrichment Factor, Geo-accumulation Index, Concentration Factor, Degree of contamination and those related to ecological risks. The results of statistical analyses and indices have shown that arsenic and chromium are the most predominant and can be, depending on the chemical form, potentially more toxic. The results of the DRX analysis show the occurrence of several minerals carrying these two MTEs, especially that of a rare mineral, Stenhuggarite, an arsenic oxide linked to hydrothermal veins. The majority of gold mining operations in West Africa are located in the birimian zone, hence the need for environmental monitoring by the relevant authorities, to prevent potential ecological risks to water and possibly health risks via the food chain.

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.

Assessment of the Degree of Contamination by Metal Traces Element （Cd, Zn, Cu, Pb） in the Environment of an Open Landfill of a Large City Part One ： A Human Population

The disposal of urban or hospital waste in open landfills is the easiest way to throw back of them without environmental concerns. MTEs （Metal Trace Elements） are the most toxic mineral elemems. This study evaluates the impact of MTE on a neighboring human population or playing near a municipal dump. Two panels were composed of adult men and children （males under sixteen years old）. Four trace metal elements were analyzed： copper, lead, cadmium and zinc. The site of the study was the municipal waste dump in Marrakech （Morocco）. The results reveal abnormal concentrations of these MTEs in blood and hair of adults and children.

Grain Size and Metallic Trace Element Contents in Sediments of Kemaman Coast, Terengganu, Malaysia, South China Sea

A total of 43 sediment samples were collected at Kemaman coast, Terengganu, by using Smith Mclntyre grab. These sediments were analyzed to determine the grain size, sediment texture and metallic trace elements. Lazer diffraction method using PSA （particle size analyzer） was used to determine the grain size and sediment texture. Teflon bomb was used to digest the sediments for metallic trace elements concentration. Results showed that the study area was dominated with sand particles （60.5%） followed by loamy sand （20.9%）, sandy clay （16.3%） and silt loam （2.3%）. On the other hand, the average concentrations of each metallic trace elements were 0.12 pg/g for Cd; 36.6 lag/g for Cr; 9.51 pg/g for Cu; 11.6 ~tg/g for N： 41.5 ~tg/g for Zn and 29.3/ag/g for Pb. Based on the results, it was found out that coarse sediments showed lower levels of metallic trace elements and higher levels in fine sediments. In addition, enrichment factor was calculated to assess the pollution status of the study area. Based on the calculation, the enrichment of metallic trace elements ranked in the following order： Pb 〉 Cd 〉 Zn 〉 Cu 〉 Ni 〉 Cr. The significant enrichment of Pb and moderate enrichment of Cd and Zn indicated that there are anthropogenic inputs while the rest of the metals can be considered from natural sources although there are effects of anthropogenic inputs in some sampling location.

Level of Contamination of Fishponds Water in Pesticide Residues and Metallic Trace Elements (Pb, Cd, As, Hg): Case of Fishponds of ZEPREGUHE (Daloa, Côte d’Ivoire)

Fishponds waters intended to satisfy the nutritional needs of the populations in terms of supply of fish resources are strongly and unfortunately exposed to the mobility and dispersion of metallic trace elements (TMEs) or to the persistence in the environment and in the form of pesticide residues from human activities. The objective of this work is to evaluate, on the one hand, the levels of identified pesticide residues and, on the other hand, those of researched TMEs (lead, cadmium, mercury and arsenic) in the waters of ponds used for fish farming in Zépréguhé, a locality located 9 km from the town of Daloa in the centre-west of C&ocirc;te d’Ivoire. The dosage of the samples carried out by means of a gas chromatograph coupled to a mass spectrometer (GC/MS) made it possible to detect nine (9) pesticide molecules, including eight (8) organochlorines and a single molecule from the pyrethroid family, obtained from the detection limit of 0.006 μg/L and the quantification limit of 0.018 μg/L. The maximum average concentration was obtained with α-endosulfan for a content reaching 0.8038 μg/L and well above the maximum admissible concentration of 0.1 μg/L. The TMEs were quantified using an atomic absorption spectrophotometer (AAS). Arsenic is the most abundant metal with an average concentration of 9.497 μg/L. With the exception of lead, these measured levels are above the acceptable limit values for freshwater. This study showed that human activities such as the use of fertilisers and plant protection products in plantations, sand extraction and road traffic have a negative impact on the quality of the water in ponds used for fish breeding.

Distribution of major and trace elements in surface sediments of Hangzhou Bay in China

The Inductively Coupled Plasma Optical Emission Spectrometer was used to analyze sediment samples collected from the Hangzhou Bay to determine major and trace elemental concentrations. Based on these concentrations, the study area can be classified into three geochemical provinces. Province I covers the northern Hangzhou Bay area and contains high concentrations of A120~, Fe203, MgO, Na20, K20, MnO, Cr, Cu, Ni, Pb, V, Co and Zn. Province III is located in the western Hangzhou Bay, near the Qiantang River mouth, and contains high concentrations of SiO~, Na20, P205~ TiO2, Cr, Sr, Zr. Province II is located in the middle and eastern Hangzhou Bay, with the medium concentrations of major and trace elements. The results also demonstrate that the grain size is the dominating factor controlling the spatial variations of elemental concentrations, and the Changjiang River （Yangtze River） and Qiantang River sediments play an important role in the distribution of these elements. Anthropogenic impact on heavy metal concentrations （especially Cr, Sr and Zr） can be detected in the surface sediments near the Qiantang River mouth.

Mineral and Trace Element Concentrations in <i>Morinda citrifolia</i>L. (Noni) Leaf, Fruit and Fruit Juice

Fruit and leaf of noni (Morinda citrifolia L.) have been used traditionally as food and for medicinal purposes by South Pacific populations since over two thousand years. Recently noni fruit juice became very popular as health beverage worldwide. Manufacturers and distributors of noni juice often praise the high content of minerals and trace elements in conjunction with the geological situation of the origin of the raw noni material. We therefore performed an investigation about the metal concentration of noni fruit, leaf and soil samples from 42 different locations in French Polynesia, and of 16 commercial noni juices. Median concentrations of metals in noni fruit, leaf and fruit juice appeared in a normal range compared to other fruits, however, the variance between different locations was considerable. Noni fruits from lime soil were poorer compared to volcanic soil in most metals. Self-prepared noni juices did generally not serve for more then 10% of the daily requirement of trace elements and minerals per 100 ml. The metal concentration in noni fruit puree was higher compared to clear juice and reached 10% and 34% of the daily requirement in 100 ml for manganese and chromium respectively. The concentrations of toxic metals (As, Cd, Pb) were below 2% of the maximum permitted levels (MPL) in all of these juices. For one of the commercial noni juices the MPL for lead was exceeded (170%) and some others were close to it. Most metals showed a good correlation regarding the concentration in noni fruit versus leaf, but not for soil versus fruit or juice. The concentration of magnesium, manganese, zinc and germanium in the commercial juices was highly correlated to the potassium concentration, indicating that these elements are useful to detect a dilution of noni juices.

Heavy metal: a misused term?

The use of the term"heavy metal"is regularly questioned by the scientific community.Here,we followed the evolution(1970–2020)in the number of published papers including this term in their title.Thus,we can evidence a continuous,albeit sometimes stabilizing,increase especially in environmental journals.After several other warning opinions,we propose that it should be replaced in the scientific literature by terms like"metal","metalloid","trace metal elements"or"potentially toxic element".

Modified accumulation of selected heavy metals in Bt transgenic rice

Safety assessment of genetically modified crops generally does not take into account the potential hazard of altered patterns of heavy metal accumulation in plants. A pot experiment was conducted under greenhouse conditions to evaluate the impact of heavy metal amendments on the accumulation of Cd, Cu, Pb and Zn in a Bt transgenic rice Ke-Ming-Dao （KMD） and its wild-type Xiushui 11 （Xs11）. In control soils, significant difference was only found in contents of Cu （p 〈 0.01） and Pb （p 〈 0.05） in straw between KMD and Xs11. At three levels of Cd amendments （5, 10, and 20 mg/kg）, the Cd contents in grain and straw of KMD were significantly higher than those of Xs11, and all grain Cd contents were significantly higher than the International Criteria （0.2-0.4 mg/kg） as specified by the Codex Alimentarius Commission （CAC）. These results implied that it may be unsafe for growing Bt transgenic rice in heavily Cd-polluted areas. No significant difference in Zn was found between the two varieties with the exception of roots at Zn amendment level of 600 mg/kg, while Pb contents in KMD were much higher in the straw at the lead amendment level of 1000 mg/kg and in the root at 250 mg Pb/kg. Data on the heavy metal accumulation patterns for the genetically modified rice may be used for the selection of growing areas as well as for plant residue management for Bt rice.

Best practices for making high integrity lightweight metal castings-molten metal composition and cleanliness control

To make high integrity lightweight metal castings,best practices are required in various stages of casting and heat treatment processes,including liquid metal composition and quality control,casting and gating/riser system design,and process optimization.This paper presents best practices for liquid metal processing and quality assurance of molten metal in both melting and mold filling.Best practices for other aspects of lightweight metal casting will be published separately.

原子吸收光谱法测定苦瓜中微量金属元素的含量

用微波消解法对苦瓜进行预处理,采用火焰原子吸收光谱法测定了苦瓜中钙、镁、铁、锌四种微量金属元素的含量。在最佳条件下测得苦瓜中各金属元素的含量分别为Ca:3843.50μg/g,Mg:2545.492μg/g,Fe:93.3415μg/g,Zn:77.685μg/g;RSD为0.19%~0.85%;检出限为0.0020μg·mL^(-1)~0.0703μg·mL^(-1);相关系数为0.9927~0.9997;加标回收率为94.60%~102.92%,此方法简单、快捷、经济、有效。

Assessment of the Risk of Toxicity of Fish in the River So by Contamination in Heavy Metals(Southern Benin,West Africa)

The purpose of this study is to assess the state of contamination of fish in the S? River by trace metal elements including Zinc, Lead, Cadmium, Copper and Arsenic. Water samples and four species of both sexes (Clarias anguillaris, Kribia kribensis, Tilapia guineensis and Eleotris vittata) were collected and analyzed. The pH, temperature and values of the chemical species present in the water of the S? River characterize an ecosystem favorable to the growth of aquatic species. The Metallic Traces Elements (MTE) concentrations vary from one fish species to another and depend on the sex and age of the animal. Zinc and copper are more concentrated in males than females with the exception of copper in Tilapia. The Pb concentration is higher in young Kribia and Clarias as well as Zn and Cd in young Tilapia. The concentrations in Cd and Pb are well above the European standards and those in the Republic of Benin, worrying results that express a health toxicity risk related to the consumption of fish of the river S?.

新疆阿尔泰可可托海矿区伟晶岩成因与矿化潜力研究:来自石英SEM-CL和微量元素的指示

新疆阿尔泰可可托海3号脉矿床是世界瞩目的伟晶岩型稀有金属Li-Be-Nb-Ta-Rb-Cs-Hf矿床。尽管前人对3号脉伟晶岩矿床已经进行了大量的研究工作,然而在伟晶岩稀有金属成矿潜力以及伟晶岩成因问题上仍存在一些争议。本文以发育在可可托海矿区不同规模的伟晶岩脉以及淡色花岗岩为研究对象,利用石英SEM-CL和原位微量元素技术手段,查明各伟晶岩脉和花岗岩的稀有金属禀赋差异及成因联系。研究结果表明,石英的Li和Al含量可以用来指示伟晶岩的矿化潜力。与1号和2号伟晶岩脉相比,3号伟晶岩脉具有更宽的分异范围,以石英中Ge/Ti变化于1.83×10^(-6)~159×10^(-6)范围为特征,更高的Li含量,其中外侧带平均Li含量为39×10^(-6),因而成矿潜力最大。此外,证实了白云母钠长花岗岩为矿化花岗岩,其微量元素组成和演化程度与3号脉伟晶岩外侧带相当,而白云母碱长花岗岩为贫矿花岗岩。更重要的是,本文利用各伟晶岩结构分带内的石英中Ge/Ti-Ge以及Ge/Ti-Al/Ti图解,确定了各伟晶岩脉具有相似的演化趋势,指示它们可能源于相同的花岗岩母岩。与世界上典型的RMG(花岗岩浆演化后残余熔浆结晶)和DPA(直接深部地壳熔融)成因的伟晶岩相比,可可托海矿区含矿伟晶岩和花岗岩中石英微量元素与RMG成因伟晶岩存在地球化学亲和性,这指示它们来源于花岗质岩浆的残留熔浆。

麋鹿被毛微量元素、重金属含量及对环境污染的监测作用

哺乳动物被毛微量元素和重金属元素含量能够反映其生活状态和栖息地状况,是环境监测中重要的生物化学指示物。对北京南海子和浙江临安两地麋鹿(Elaphurus davidianus)种群被毛中的10种重金属和34种微量元素进行测定,以期探讨麋鹿被毛微量元素和重金属含量在栖息环境监测中的可行性。结果表明:除Re元素外,其余43种元素在麋鹿被毛中均被检出,统计分析表明Li、Be、Sc、V、Co、Ga、Rb、Ir、Mo、Cd、Cs、Ba、La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Tl、Bi、Th、U、Nb、Ta、Zr和Hf 34种元素为麋鹿被毛的特征元素;与北京南海子麋鹿种群相比,浙江临安麋鹿种群被毛中的微量元素Sr、In、Sb、W、Bi、U和重金属元素Zn、Cu、Cr、Pb、Cd含量更少,其余32种元素含量均高于北京南海子麋鹿种群;独立样本t检验分析表明,麋鹿被毛微量元素和重金属元素含量存在地域差异性,仅Cr(p=0.064)、Ni(p=0.769)、Mo(p=0.129)、Tl(p=0.065)、Zr(p=0.138)和Hf(p=0.057)6种元素差异不显著,其余37种元素差异均显著;北京南海子和浙江临安麋鹿种群的栖息环境和食物均未受到Zn、Cu、Cr、Pb、Cd、V、Co、Ni、Sb和Tl 10种重金属元素污染的威胁。研究表明,麋鹿被毛可作为栖息环境重金属污染的非损伤监测指示材料。

Elemental Quantification in Intradermal Tattoo-Inks by Means of Total Reflection X-Ray Fluorescence

This work describes the application of a detailed set of TXRF evaluations to the elemental content of assorted tattoo inks, on the market of the city of Concepcion, Chile. We applied TXRF as a screening method for determining the composition in 3 sets of tattoo inks, in order to establish, from an inorganic point of view, the composition and purity of the samples, evaluating their elemental innocuousness. The analyzed 48 products were freely acquired from on line suppliers. All of them were analyzed by external standard quantification, but in order to inter-compare the results, a 15% of the samples were acidly digested and then quantified by the internal standard method. In the samples we determined: 1) their inorganic quantitative composition and, 2) the possible presence of elements which are potential health hazards. In this study few anomalies were found: 1) The high presence Ti of and W in few samples, 2) Arsenic was found in four of them, and 3) A trace detection of a rare earth element in a particular product. The products studied are almost freely imported from a world open marked, so the questions about their innocuousness could affect not only to the Chilean society.

电容器薄膜用聚丙烯原料微量元素分析方法

为了精确分析电容器薄膜用聚丙烯原料中微量元素,介绍了电容器薄膜用聚丙烯原料进行元素测定时的干法灰化法以及微波消解法两种预处理方法,比较了不同方法对分析结果的影响。对比了几种分析手段的特点,选择电感耦合等离子体质谱法作为分析手段。相比于干法灰化法,微波消解法的准确度和精密度都较高,微波消解法结合ICP-MS法适用于测定电容器薄膜用聚丙烯原料中的微量金属元素,建立了基于ICP-MS法测定电容器薄膜用聚丙烯原料中微量金属元素含量的方法。