Concentration Levels Of Trace Elements Research Articles

Distribution Characteristics and Influencing Factors of Bio-elements in the Human Hair of Uyghur Communities in an Oasis Area of Xinjiang, China.

Located in central Asia, Xinjiang is characterized as a diverse environment in China, consisting of vast deserts, dotted oases, and high mountains. Due to the combined effect of climate conditions under such a diverse environment, there are large differences in human activities, living styles, and eating habits in farmland and grazing pastures between Xinjiang and other regions of China. This study aimed to investigate the variations and mechanisms of elemental distribution in the hair of Uyghur communities among different ages and genders and under different land use backgrounds in an oasis region in Xinjiang. Hair samples from 524 residents from four traditional farmland areas and two grazing pasture areas in Bai Cheng County in Xinjiang were collected, and the levels of thirteen elements were analyzed. The results indicated that the average levels of Cu, Mg, Mn, Zn, Ni, Co, Pb, Fe, Ca, Cd, Cr, As, and Se in the hair of Uyghur communities were within the background levels of Chinese and global residents' hair. Overall, the levels of elements in the hair of women residents were higher than those of men residents. The levels of elements in the human hair of the middle-aged group were higher than those of child and older-aged groups. Elements Cr and Se in the hair of grazing pastures were higher than those of farmland areas. The levels of Cd, Pb, As, and Zn in the hair of farmland areas were higher than those of grazing pasture areas. The levels of Ca, Mg, Cu, and Fe in the hair of Uyghur communities were higher than those of other ethnic groups, while the toxic elements in the hair of residents in Bai Cheng were lower than those in other regions of China. Middle-aged people were exposed to higher levels of toxic elements in their daily activities compared to elderly and child groups. Also, adult groups need much more nutrients for their growth and intellectual development compared to child and elderly groups. The change in land use from grazing pastures to farmland increased the toxic trace element concentration levels in human hair. The significant differences in the overall concentration levels of elements in human hair among the different ethnic groups and regions can be attributed to the differences in lifestyles, cultural customs, dietary habits, and internal and external exposure routes.

A case-control study on the relationship between urine trace element levels and autism spectrum disorder among Iranian children.

Autism spectrum disorder (ASD) is a type of neurodevelopmental disorder characterized mainly by qualitative deficiencies in social communication skills, accompanied by repetitive and restricted behavior patterns. This study was conducted to investigate the associations between the risk of ASD development in children and exposure to trace elements (arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn)). Two groups of children, including 44 ASD and 35 typically developing (TD) children, were selected, and their fasting urine samples were obtained. The concentration levels of trace elements were assayed using ICP-MS. The results showed that as compared to the TD group, the concentration levels of As (p = 0.002) and Pb (p < 0.001) and also Cr (p < 0.001), Cu (p = 0.001), and Ni (p < 0.001) were significantly higher among ASD children. In terms of gender, boys with ASD showed elevated levels of Cr, Cu, Ni, and Pb, whereas the urine levels of As, Cr, Cu, Ni, and Pb were markedly higher among girls when compared to the non-ASD children. Under the logistic regression model, the risk difference for As, Co, Cr, Cu, Ni, Pb, and Zn remained significant when adjustment was applied for age and gender confounders.

Major and trace elements changes of female methamphetamine addicts during six months’ compulsory treatment: Biomarkers discovery

BackgroundThe concentration levels of major and trace elements are significantly correlated with human health. However, studies profiling major and trace elements among female using methamphetamine are rare. This study aims to investigate the major and trace elements changes and discover elemental biomarkers in plasma of female methamphetamine (METH) addicts in six months’ compulsory treatment. MethodsA total of 60 female METH addicts selected from drug rehabilitation center were randomly divided into three equal groups: (1) Detoxification for one month; (2) Detoxification for three months; (3) Detoxification for six months. Twenty healthy women, without drug abuse history were selected as control group. Four major elements including Na, Mg, K, Ca and twelve trace elements including V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Mo, Sn, Pb were determined using inductively coupled plasma mass spectrometry (ICP-MS). The results were analyzed using One-way Analysis of Variance (ANOVA) and Student-Newman-Keuls (SNK test). Elemental biomarkers were discovered based on orthogonal partial least squares discriminant analysis (OPLS-DA). ResultsThe four groups used in the study were divided into four significant sections according to scatter plots. The total elemental concentrations of three METH withdrawal groups were increased compared to the control group. Over six months, element contents of the withdrawal groups gradually equaled element contents of the control group in compulsory treatment. The variable importance in the projection values (VIP > 1) of OPLS-DA model and SNK test (p < 0.05) revealed Fe, Cu, Cr and Se as elemental biomarkers. ConclusionMajor and trace elements demonstrated significant differences between control group and three METH withdrawal groups. Fe, Cu, Cr and Se are potential elemental biomarkers among METH-abused female groups. Metabolic disorders of major and trace elements exist in the female methamphetamine addicts.

Assessment of the concentration levels of heavy and trace elements in fish using Proton-Induced Gamma Emission

ABSTRACT Fish plays an essential role in Bangladesh people’s diet, being the leading and sometimes easily replaceable food of low-income households. Major and minor elements in fish are crucial for the biological process in the human body. The analyses of 18 distinct elements (Na, Mg, Al, Ca, V, Cr, Mn, Fe, Cu, Zn, Se, Br, Rb, Sr, Cd, I, Pb) in 6 selected fishes consumed by the people who live in the Savar region of Dhaka city in Bangladesh were conducted. The objective of the present analysis is to assess the concentration of heavy and trace elements in these fishes and provide up-to-date information if these fishes are safe to eat. The Proton-Induced Gamma Emission technique and the High Purify Germanium detector were used to detect the characteristic Gamma-rays from the target and then calculate the concentration of elements. In general, the highest concentrations range was typically found in K, Ca, and Fe, while the lowest concentrations range were found in V, Cd, and Pb. The findings were compared with the allowable limits of the International Atomic Energy Agency (IAEA-407) and the World Health Organisation/Food and Agriculture Organization (WHO/FAO).Fish are a key source of protein for millions of Bangladeshi citizens, particularly households with low incomes, so monitoring the toxicity level of fish is very crucial. The present analysis results indicate that these fishes are not entirely free of health hazards in consumption. Further study will provide crucial information on the relationship between the concentration of elements and human health.

Ecological and health risk assessment of trace elements in surface soil in an arid region of Xin Jiang, China

Trace element pollution in soil has become an increasingly common issue and potentially harms the environment and human health. In this study, the contamination levels and ecological and health risk indices of trace elements in surface soils in Bai Cheng, Xin Jiang, were investigated in order to examine if the land usage changed from pasture to agriculture has influenced the behaviours of these trace elements. In this study, descriptive analysis, normality test, the Tukey-HSD method and non-parametric methods were used to investigate the characteristics of trace elements. The geo-accumulation pollution and ecological risk indices were used to analyse the degree of contamination by trace elements. Correlation and principle analyses were used to identify the sources of trace elements and a health risk assessment was used to analyse human exposure to trace elements of the soil. Cadmium was the main pollutant in the 0–5 cm soil layer in both agricultural and pastoral areas. Thus, it contributed most to the Geo-Accumulation Index (Igeo) and the comprehensive potential ecological risk index (RI) of the surface soils. The levels of RI for the topsoil layer of agricultural areas fell into moderate to high (II-III) ecological risk categories, and those of pastoral areas belonged to low to moderate risk categories (I-II). Both values of Igeo and RI of the surface soils in agricultural areas were higher than in pastoral areas. The carcinogenic risk of Cr through hand-to-mouth intake and the total risk of trace elements in soils for humans were higher than the safety reference level. Chromium was the greatest contributor to total carcinogenic risk. Trace element concentration levels in surface soils in pastoral areas were relevant to geochemical characteristics and atmospheric deposition, whereas trace element concentration levels in surface soils in agricultural areas were derived not only from geochemical characteristics but also from human activities. The change in land use from pasture to agriculture increased the trace element concentration level in surface soils. There were both ecological risks and human health implications for residents exposed to such contaminants of soils in the studied region.

Dietary intake assessment of macro, trace, and toxic elements via consumption of kimchi in South Korea.

Kimchi, a Korean food, is now produced and consumed in many other countries. In this study, the macro, trace, and toxic element content in varieties of kimchi from Korea and China was evaluated. A health-risk assessment, involving the calculation of estimated dietary intake values, was undertaken. To discriminate among samples with different origins, linear discriminant analysis (LDA) and principal component analysis (PCA) were applied. The analytical methods used for analyses were successfully validated. In the quantification of elements, no significant differences were detected in the concentrations of the elements that were analyzed. Based on the fresh weight of kimchi, among the macro elements, the concentrations of Na and K were relatively high, with values of 4181.9-9919.8 mg kg-1 and 1661.8-6623.5 mg kg-1 , respectively. Among the trace elements that were analyzed, zinc in Korean samples, and strontium in Chinese samples showed the highest concentrations, at 2.67 and 2.98 mg kg-1 , respectively. Concentration levels of the toxic trace elements were within permissible limits. The amount of daily intake and provisional daily intake of each element calculated based on kimchi intake confirmed its safety for consumption. Linear discriminant analysis and PCA successfully discriminated among the samples of Chinese and Korean origin. The provisional daily intake of the toxic elements was within provisional tolerable daily intake values. The normal intake of kimchi could not pose a threat upon consumption. © 2019 Society of Chemical Industry.

Determination of the content of metals in used lubricating oils using AAS

This article focuses on the results of investigations of selected heavy metals (Mg, Fe, Ni, Cu, Zn, Pb, Ca, Cr and Al) in engine oils of various manufacturers. The measurements were made using atomic absorption spectrometry (AAS) THERMO-iCE 3000 Series. The aim of the study was to determine the concentrations and the direction of changes of those heavy metals and to determine the statistical relationship between the car mileage and the concentration levels of individual trace elements. Statistical analysis of the test results showed significant changes in iron and copper concentrations in engine oil, depending on the engine's operating history.

Association of Periodontitis with the Concentration Levels of Germanium and Tin in Hair.

The purpose of this study was to investigate whether or not the concentration levels of certain kinds of trace elements in hair are associated with periodontitis. We studied a total of 109 participants, which are composed of 25 participants with periodontitis and 84 participants without periodontitis. Periodontal conditions were assessed by measuring the periodontal clinical attachment loss and pocket depth, which were determined at six sites of all teeth. Periodontitis was defined according to the criteria of periodontitis proposed by CDC-AAP. The hair samples were washed with acetone, water, and extran (1%v/v), and then aliquots of hair samples were wet-ashed. This sample solution was analyzed by Perkin-Elmer Mass Spectrometer. The odds ratios and 95% confidence intervals of the concentration levels of trace elements for periodontitis were calculated by multivariate logistic regression analysis. After adjusting all confounders, it was found that the higher concentration level of germanium in hair was significantly and positively associated with periodontitis (odds ratio [OR] 7.12; 95% confidential interval [CI] 2.03-25.00). The higher concentration level of tin in hair was significantly and negatively associated with periodontitis (OR 0.27; 95% CI 0.08-0.94). It was concluded that there was a significant relationship between periodontitis and the concentration level of germanium and tin in hair.

Trace elements determination by ICP-QMS in octopus edible samples from Mexico City markets

The purpose of this study was to evaluate the total concentration levels of trace elements (Cr, Cu, Mn, Pb, Rb and Sr) in octopus’ mantle and tentacles samples from Mexico City markets, by using the Mexican regulation applied to food for human consumption. The determination of both essential (Cr, Cu, Mn) and non-essential (Pb, Rb and Sr) trace elements was made by inductively coupled plasma-quadrupole mass spectrometry (ICP-QMS). The samples were collected from local markets and supermarkets from each of 16 delegations of Mexico City, Distrito Federal. The overall ranges of concentrations found were: 2.4-4.8, 5.1-95.3, 1-6, 0.1-1.6, 0.4-4.5 and 11-58 mg/kg for Cr, Cu, Mn, Pb, Rb and Sr, respectively. The maximum and mean concentration values obtained for Cu and Cr in mantle and tentacle samples from both kind of markets, are above of the NOM-051-SCFI/SSA1-2010 (closest Mexican standard), according to USDA National NDB for Standard Reference consumer exposure (100g/day) of octopus. It was observed that the maximum Pb concentration value found in mantle and tentacle samples from supermarkets origin exceeds the NOM-129-SSA1-1995 and NOM-242-SSA1-2009 reference values, while the maximum mean value is below the regulation. Similar Mexican regulation data for Mn, Rb and Sr were not found.

Unravelling provenance and recycling of late antique glass from Cyprus with trace elements

Earlier research has shown that several common late antique glass types circulate in Cyprus between the fifth and the seventh century AD, specifically Levantine 1, HLIMT, HIMTa, HIMTb and Egypt 1, HIT, Roman and a plant ash glass. By investigating the glass material from Yeroskipou-Agioi Pente, Maroni-Petrera, and Kalavasos-Kopetra, we aimed to refine the chemical groups present within three late antique Cypriot sites and define the relations between trace elements obtained from LA-ICP-MS. Our data demonstrate compositional patterns that can be exploited to provenance late antique glass by investigating the REE-bearing mineral fractions, the amount of zircon and the carbonaceous fraction of the sand. In addition, Nb and Ti display a strong linear relation which depends on the glass type. Finally, the paper discusses the occurrence of glass recycling on the island and how this activity influenced the concentration levels of specific trace elements. Our study thus sets out an analytical framework to identify recycling events tailored on each compositional type.

Natural and anthropic effects on hydrochemistry and major and trace elements in the water mass of a Spanish Pyrenean glacial lake set.

This study presents the key hydrochemical characteristics and concentration levels of major (Ca, Mg, Na, Si, K, Sr, Fe) and trace (Ba, Sc, Cr, Mn, Al, As, Li, Co, Cu, U, Pb, Hg, Au, Sn, Zn, Cd, Ag, Ni) elements in the water mass of four selected Pyrenean cirque glacial lakes (Sabocos, Baños, Truchas and Escalar tarns) with different catchment features, between 2010 and 2013. Resulting data set is statistically analyzed to discriminate between the natural or anthropic origin of the elements. Analyses indicate that in all cases, the main source of most major and trace elements is geological weathering, being thus individual bedrock composition the main driver of differences between lakes. Several anthropogenic sources of airborne Cu, Sc, Co, and Cr must be also considered. The shallowness of the lake is also a factor that may influence element cycling and concentration levels in its water mass. Concentrations of anthropogenic elements were low, comparable to those reported in other glacial lakes, way below the WHO, US EPA, EC, and Spanish legal limits for drinking water quality, indicating the absence of serious pollution. Toxic heavy metals Cd, Pb, Hg, and Zn were not detected in any of the tarns.

Distribution and Source of Trace Elements in Marine Aerosol of Mersing, Johor, Malaysia

Particulate matter samples with diameter less than 10 μm (PM10) were collected from the coastal area of Mersing, Johor Meteorological Station to investigate external sources of trace elements injected into the marine atmosphere. The concentrations of PM10 in the 47 samples for over two years of sampling period between January 2009 and December 2010 were ranged from 8 μg/m3 to 87 μg/m3, and a weak negative statistical correction (r=0.139) with daily rainfall were observed except for certain inter-monsoon period. While the concentration of trace elements such as Na, Ba, Al, K and Ca were classified as major metals ranging in concentration from 1 μg/m3 to 100 μg/m3. Other elements comprising Mg, Fe, Sr, Cr, Cu, Pb, Mn and Ni were classified as intermediate metals with concentrations ranging from 1 ng/m3 to 1000 ng/m3. Also detected were Co and Cd, but these were classified as minor metals with concentration levels of less than 1 ng/m3. The fluctuate concentration levels of trace elements in PM10 also found at study area were directly corresponded to the source of particulate matters, but the concentration levels of particulate matters were influenced by monsoon events. Trace metal compositions in the PM10 and the PMF (positive matrix factorization) model have shown a significant presence of terrestrial soil sources especially the by-product of biomass burning (53%) together with terrestrial soil, crustal dust (34.9%), and mixture of anthropogenic sources (12%).

Trace elements in hazardous mineral fibres

Both occupational and environmental exposure to asbestos-mineral fibres can be associated with lung diseases. The pathogenic effects are related to the dimension, biopersistence and chemical composition of the fibres. In addition to the major mineral elements, mineral fibres contain trace elements and their content may play a role in fibre toxicity. To shed light on the role of trace elements in asbestos carcinogenesis, knowledge on their concentration in asbestos-mineral fibres is mandatory. It is possible that trace elements play a synergetic factor in the pathogenesis of diseases caused by the inhalation of mineral fibres. In this paper, the concentration levels of trace elements from three chrysotile samples, four amphibole asbestos samples (UICC amosite, UICC anthophyllite, UICC crocidolite and tremolite) and fibrous erionite from Jersey, Nevada (USA) were determined using inductively coupled plasma mass spectrometry (ICP-MS). For all samples, the following trace elements were measured: Li, Be, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, As, Rb, Sr, Y, Sb, Cs, Ba, La, Pb, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, U. Their distribution in the various mineral species is thoroughly discussed.The obtained results indicate that the amount of trace metals such as Mn, Cr, Co, Ni, Cu and Zn is higher in anthophyllite and chrysotile samples, whereas the amount of rare earth elements (REE) is higher in erionite and tremolite samples. The results of this work can be useful to the pathologists and biochemists who use asbestos minerals and fibrous erionite in-vitro studies as positive cyto- and geno-toxic standard references.

Distribution and leaching characteristics of trace elements in ashes as a function of different waste fuels and incineration technologies

Impact of waste fuels (virgin/waste wood, mixed biofuel (peat, bark, wood chips) industrial, household, mixed waste fuel) and incineration technologies on partitioning and leaching behavior of trace elements has been investigated. Study included 4 grate fired and 9 fluidized boilers. Results showed that mixed waste incineration mostly caused increased transfer of trace elements to fly ash; particularly Pb/Zn. Waste wood incineration showed higher transfer of Cr, As and Zn to fly ash as compared to virgin wood. The possible reasons could be high input of trace element in waste fuel/change in volatilization behavior due to addition of certain waste fractions. The concentration of Cd and Zn increased in fly ash with incineration temperature. Total concentration in ashes decreased in order of Zn>Cu>Pb>Cr>Sb>As>Mo. The concentration levels of trace elements were mostly higher in fluidized boilers fly ashes as compared to grate boilers (especially for biofuel incineration). It might be attributed to high combustion efficiency due to pre-treatment of waste in fluidized boilers. Leaching results indicated that water soluble forms of elements in ashes were low with few exceptions. Concentration levels in ash and ash matrix properties (association of elements on ash particles) are crucial parameters affecting leaching. Leached amounts of Pb, Zn and Cr in >50% of fly ashes exceeded regulatory limit for disposal. 87% of chlorine in fly ashes washed out with water at the liquid to solid ratio 10 indicating excessive presence of alkali metal chlorides/alkaline earths.

A rapid microwave-assisted acid extraction method based on the use of diluted HNO3-H2O2 followed by ICP-MS analysis for simultaneous determination of trace elements in coal samples

Before coal processing such as pyrolysis, liquefaction, gasification and combustion, it is very crucial to monitor the trace element concentration levels as that determines the coal quality. Therefore, the current study describes the development of microwave-assisted acid extraction (MW-AAE) method for extraction of 15 trace elements in coal samples prior to their determination using inductively coupled plasma-mass spectrometry. Diluted HNO3-H2O2 was used in order to reduce reagents amount used, eliminate matrix interferences caused by concentrated acids and to decrease waste produced in analytical laboratories. The optimisation of the proposed extraction method was carried out by using a full factorial design (24) involving four factors; that is, temperature, extraction time, HNO3 and H2O2 concentrations. The optimum conditions for the MW-AAE procedure were found to be 200°C, 5 min, 5 mol L−1 and 2 mol L−1 for temperature, extraction time, HNO3 and H2O2 concentrations, respectively. Under optimum conditions, the accuracy of the MW-AAE method was examined by analysing three coal certified reference materials (SARM 18, 19 and 20) and recoveries of 80–115% were achieved for V, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Sr, Zr, Cs, Ba, Pb and U, except for Ti (10–25%) and Hf (27–70%). In addition, the precision of the proposed method, expressed in terms of relative standard deviation (SD) (n = 15), was within the accepted range (≤3.5%). The method detection limits of 0.001–0.57 µg g−1 for all trace elements under the investigation were similar to the literature reported work, except for Ti (4.00 µg g−1).

Analysis of Trace Elements in Groundwater Using ICP-OES and TXRF Techniques and Its Compliance with Brazilian Protection Standards

In this work, an assessment of groundwater quality and its compliance with Brazilian environmental protection standards was carried out. Ground waters from the Serra Geral aquifer are currently used for human consumption at the western region of the Brazilian state of Parana. Ground water samples from 10 wells covering the entire Toledo municipality rural region were collected and analysed by two highly accurate and sensitive spectrometric techniques: inductively coupled plasma–optical emission spectrometry (ICP-OES) and total reflection X-ray spectrometry (TXRF). Among all detected elements, 18 elements (As, Ba, Br, Ca, Pb, Cl, Co, Cu, Cr, Fe, P, S, Mn, Ni, K, Ti, V and Zn) were measured by the TXRF technique while three elements (B, Mg and Na) were measured by ICP-OES. Trace element concentration levels were then compared with Brazilian environmental legislation (BEL). From the results obtained, concentrations of chromium, iron, arsenic, selenium, manganese and barium were detectable in some wells at slightly above the maximum limits allowed by the BEL.

Trace element concentration levels in three bird species in Hormod Protected Area, Larestan, Iran

The objective of the present study was to investigate the levels of Cd, Pb, Co, and Cu, in A. chukar, A. griseogularis, and Columba livia, in order to (1) examine the age- and gender-related variation in trace metal accumulation and (2) to determine the significance between metal concentrations in the kidney, liver, and pectoral muscle. Mean concentrations of Cd and Pb in the kidney of A. chukar, A. griseogularis, and C. livia were 3.7, 4.1, and 3.9 µg/g and 15.9, 13.6, and 15.5 µg/g, respectively. In the liver, they were 4.8, 4.3, and 3.9 µg/g and 21.4, 21.3, and 21.1 µg/g, and in the pectoral muscle, 2.3, 2.3, and 2.2 µg/g and 7.1, 7.1, and 7.8 µg/g, respectively. Metal concentrations in three bird species were decreased in the sequence of liver > kidney > pectoral muscle. Trace metal concentrations in the three species were higher in females than in males. The mean concentrations of Cd in the kidney and liver were higher than the background levels, as well as Pb concentrations in the liver were higher than the toxic level.

Determination of trace elements in nutrition materials in Kingdom of Saudi Arabia

Four types of edible tubercular roots cultivated in Saudi Arabia are analysed through sequential determination of certain essential and toxic trace elements by inductively coupled plasma atomic emission spectrometry (ICP-AES). Comparable runs carried out using both flame and graphite atomic absorption spectroscopy (AAS). Radish proved to contain the highest concentration level of iron (>21 μg/g), onion contains high concentration of zinc and strontium (~ 6 and 9 μg/g) and potato was found to contain the highest concentration level of copper (~2 μg/g). Samples of carrots, radish and potato collected from different locations are also analysed to study the effect of cultivation area on the concentration levels of trace elements in edible tubercular roots. Variation in the concentration levels of iron, zinc, copper, cobalt, strontium, cadmium and lead in each type of test samples seem not to be significant. Detailed studies seem necessary to throw further light on the effect of different of sample location on the concentration levels of both essential and toxic trace elements in different vegetable materials; especially those cultivated in areas neighboring various industrial and other human activities in Saudi Arabia. Key words: Tubercular roots, trace elements, inductively coupled plasma atomic emission spectrometry (ICP-AES), atomic absorption spectroscopy (AAS) analysis.

Using fuzzy clustering algorithms to describe the distribution of trace elements in arable calcareous soils in northwest Iran

Accumulation of trace elements in arable soils is an important global hazard worldwide. In this research, the available content of Zn, Fe, B, Co, Cu, Mn, Mo and other soil parameters (pH, organic carbon content, carbonates and electrical conductivity) were analysed in northwest Iran. Concentration levels of trace elements were relatively low in areas with high pH values and low organic matter content, and only the Mo value exceeded the reference threshold. Based on the correlation among the elements, two datasets were produced. The first consists of Fe and Mn data, while the second contains Zn, B, Co, Cu and Mo data. Two fuzzy clustering approaches, Fuzzy C-means (FCM) and Gustafson–Kessel (GK), were applied for clustering both datasets. Multiple accumulation of trace elements was investigated from the clustering results and then visualized in spatial regionalization maps. The fuzzy clustering evaluating indices showed that the GK method was more appropriate than FCM for clustering datasets. The results revealed that the first and second datasets were divided into seven and six clusters, respectively. Fuzzy clustering analyses combined with geostatistical methods were used to map the spatial variability of each cluster. This method enabled the monitoring of multiple metal accumulation in large agricultural soils.

Trace Elements and Health: An Environmental Risk in Nigeria

The concentration levels of trace elements in drinking water and food pose potential health risks to man and therefore require great attention. Studies on iodine deficiency disorders (IDD) indicate goiter prevalence in areas underlain by metamorphic Basement and Younger Granite rocks and its near absence in the sedimentary terrains. There are cases of dental fluorosis resulting from the excessive ingestion of fluoride in both children and adults living in both the crystalline and sedimentary terrains in Nigeria with none reported from the coastal areas. Mining/mineral processing predisposes these trace elements to weathering whereby they are released into the environment in the soil and water bodies. The incidence of abnormally high natural radiation (radon gas) associated with most rocks and the exceptionally higher natural radiation associated with cassiterite mill tailings of the Jos Plateau, north central Nigeria, is a source of worry. Epidemiological records have indicated the increasing rate of lung cancer prevalence on the Jos Plateau and studies carried out elsewhere in Europe have linked about 13% of deaths associated with lung cancer to exposure to natural radiation. Preliminary hydro-geochemical study indicates high concentrations of potentially harmful elements (PHE) (Pb, Cu, Zn, As, Cd, Hg, V, Co, Cr, Ni, etc.) in the soils and water bodies in the crystalline and inland sedimentary terrains especially close to sulfide mineralization. In addition, high levels of these elements from anthropogenic sources have also been reported in soils and water in most mining/mineral processing sites and urban centres. The knowledge of the relationships between trace elements and human health issues is at its infancy in Nigeria. To adequately understand these relationships, there is need for geoscientists to intensify research on trace elements in the environment and together with professionals in community health so as to identify health issues arising from trace elements in the environment.