Concentration Levels Of Elements Research Articles

The use of atomic absorption technology as a diagnostic and monitoring tool for some diseases: A review between 2010 and 2022

Atomic absorption technology is considered one of the important technologies in many different scientific fields because it is of a specification and diagnosis nature. Therefore, we decided to make a review about this technology over the years from 2010 to 2022 and the studies that used this technology in the fields of chemistry, physics, and medicine, and it's very important relationship in diagnosing the levels of element concentrations. Necessary, trace, toxic, etc. We have found that it is very effective in this aspect and provides scientific research with many relevant positives. Therefore, we advise researchers to use it and to delve into broader fields by using it in more comprehensive and advanced research and to work on developing the technology in terms of work and diagnosis.

Temporal change of potential toxic element contamination, ecological and toxicological risk in holocene in Southern Black Sea coasts (Türkiye)

This study was carried out to evaluate the temporal variation of the potential toxic element concentration and ecological risk level during the Holocene along the Southern Black Sea coasts. Ecological and ecotoxicological indices such as enrichment factor (EF), modified ecological risk index (mRI), modified potential ecological risk index (mPER) and toxic risk index (TRI) were used in the study. Anthropogenic effects were determined to be more dominant in the western and middle parts of the Southern Black Sea Region. As, Cu, Pb, Zn, Cd, Hg, Ni enrichments were observed in the last 200 – 300 years and the potential risk index values related to them increased. Source of enrichment detected in the cores was found to be related to the volcanic activities that occurred in different geological periods. It was determined that the increases in PTE concentration observed specifically in the middle parts of the cores coincided with the dates of the volcanic activities observed in Anatolia.

Concentration, speciation and risk effects of multiple environmentally sensitive trace elements in respirable fine-grained fly ash

Respirable fine-grained fly ash (RFA) is captured very inefficiently by existing air purification devices of power plant, leading to increasing concerns regarding their migration and subsequent interaction with body due to fine particle size and its complex toxic composition. Trace elements of RFA in three groups with five different sizes between 8–13 µm were analyzed in terms of available concentration, speciation and risk effects. The concentration, pollution level and ecological risk level of elements in RFA were related to particle sizes. Chronic non-carcinogenic effect risk (NER) and carcinogenic effect risk (CER) were negatively correlated with particle size. The individual weight of exposed subjects, corresponding trace elements concentration and ingestion rate in RFA were three significant variables influencing CER. NER and CER had a tenfold exaggerated effect when calculated using total element concentration of RFA. In addition to individual differences and exposure conditions, trace element properties, speciation and available concentration were the dominant factor responsible for ecological and environmental effects of trace elements in RFA, following the order As>Ni, Mn>Cr>Pb>Cu>Zn. Results of this work highlight the effects and differences of trace elements in RFA on ecology and health, and provide a basis for further pollution control and human health warning.

Nutritional Content, Antimicrobial Study and Isolation of Quercetin from Ziziphus spina-Christi Leaf

Plant has been the major source of medicinal globally. This study aimed at determining the nutritional composition, antimicrobial activity and isolation of phytochemical from the leaf of Ziziphus spina-Christi. Proximate composition, elemental (Ca, Na, Mg, K, P, Cu, Cd, Fe, Ni, Zn) concentrations, phytochemical screening and antimicrobial activity were carried out using standard protocols. Column chromatographic elution process was used to fractionate the methanol extract and Preparative TLC was used to isolate a compound. The result of the proximate composition and elemental concentration levels showed that the leaf is nutritious. Phytochemical screening showed the presence of alkaloids, cardiac glycosides, flavonoids, saponins and tannins. The methanol extract inhibited the growth of Escherichia coli, Salmonella typhi, Staphyloccocus aureus and Bacillus subtilis significantly at extract concentrations of 100, 200, 300, 400 and 500mg/mL was used, thus having antimicrobial activity. The compound isolated has 114-116oC melting point (uncorrected) with a single banding pattern confirmed by TLC study. Physical and chemical tests of isolated compound were conducted. By using IR,1H-NMR and 13C-NMR spectra of the isolated compound was confirmed as Quercetin – a flavonoid.

Prediction of Au-Associated Minerals in Eastern Thailand Based on Stream Sediment Geochemical Data Analysis by S-A Multifractal Model

Conducted within the scope of geochemical exploration in eastern Thailand, this study aims to detect geochemical anomalies and potential mineral deposits. The objective was to interpret intricate spatial dispersion patterns and concentration levels of deposit pathfinder elements, specifically arsenic (As), copper (Cu), and zinc (Zn), using a comprehensive array of stream sediment geochemistry data. Methodologies involved integrating multifractal properties and traditional statistics, facilitated by the GeoDAS and ArcGIS platforms as instrumental analytical tools. In total, 5376 stream sediment samples were collected and evaluated, leading to the development of an in-depth geochemical map. The results indicated distinct geological units marked by substantially elevated average values of the aforementioned elements. Identification of geochemical anomalies was achieved through the spatial distribution method and the subsequent application of the spectrum-area (S-A) multifractal model. An intriguing link was found between high As concentrations and gold deposits in the area, suggesting As as a viable pathfinder element for gold mineralization. The anomaly maps, generated from the stream sediment data, spotlighted potential zones of interest, offering valuable guidance for future mineral exploration and geological inquiries. Nonetheless, it is vital to recognize that the increased values noted in these maps may be influenced by regional geological factors, emphasizing the necessity for a diverse set of analytical methods for accurate interpretation. This study’s significance lies in its pioneering use of the S-A multifractal model in geochemical data analysis. This innovative approach has deepened our comprehension of geochemical dispersion patterns and improved the precision of mineral exploration.

Environmental Assessment for Concentration of Heavy Metals Due to the Industrial Activity in the Soils of Samawah and Al-Khader Districts

Objective: The current study concluded with the evaluation of the concentration level of heavy elements due to industrial activity in the soils of Samawah and Al-Khader districts, represented by elements (cadmium Cd, cobalt Co, copper Cu, nickel Ni, lead Pb). Samples were taken from (17 sites) affected by industrial activity, and a region One reference point away from the impact of industrial activity, at a single depth of (0-40 cm), with a total of (180 measurements), (90 measurements) in winter and another in summer, for each site (10 measurements). Methods: The current research was based on the descriptive analytical approach in describing the phenomenon and analyzing it spatially, and the systematic approach in revealing the geographical factors causing the variation in the values of heavy elements due to industrial activity in the soils of Samawah and Al-Khader districts. Results: Industrial activity contributes to increasing the concentration of some heavy metals in the soils of the study area. The concentrations of heavy elements varied as a result of the industrial activity in the soils of the Samawah and Al-Khader districts, clearly between them. Their general rates are (101.5415, 38.2659, 25.7814, 9.7475, 0.5574 ppm). Conclusion: Environmental awareness about the behavior of the owners of industrial activities and directing them to the need to preserve the soil, through audio and visual environmental awareness and explanatory seminars. On the other hand, the necessity of adhering to the application of environmental requirements according to the type of industrial activity and the imposition of fines and environmental closures in the event of non-application of environmental standards. Orientation towards environmental studies and scientific research in the field of environmental pollution and harnessing them in solving environmental problems, including soil pollution.

Elements and sugars in kelp and fucoid species in Greenland, correlation and seasonality

Greenland seaweeds constitute an arctic marine resource as well as being important monitoring organisms in connection with arctic mining activities. In both cases, the natural element content, and its potential seasonal variation, is important knowledge for designing a monitoring programme and for planning of harvest for highest biomass quality and value. Therefore, concentration levels of 54 elements and two sugars (laminarin and mannitol) were obtained in seven different seaweed species of relevance for monitoring and commercial harvest sampled in the same location in Greenland across all seasons during two years. The kelp species sampled were Agarum clathratum, Alaria esculenta, Hedohyllum nigripes, Saccharina latissima, and the fucoids Ascophyllum nodosum, Fucus distichus and F. vesiculosus. The thallus samples were analysed for element concentration levels by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), and the monosaccharides were separated by HPAEC ion exchange and detected using Pulsed Amperometric Detection (gold electrode). The results showed, in the studied location, and on average, that the dominant major and minor elements are potassium, sodium, calcium, magnesium and phosphorus with mean concentration levels > 4800 μg g−1. The trace elements are dominated by iron, aluminium and arsenic with mean concentration levels > 61 μg g−1. Concentration levels of elements were in general seaweed species specific. Seasonality was not tested statistically significant for most of the elements when data were pooled in summer and winter months, although higher concentration levels during winter could be observed. Thus, the content of laminarin and mannitol is highest during late summer, thus July–October/November may be the time window for optimal harvest yield with respect to those compounds, although narrower time windows may be considered, depending on the species harvested. Regarding unwanted compounds such as As and I, harvesting time of the year seems not to cause a profound difference on the quality of the biomass.

Anaerobic Digestion Remediation in Three Full-Scale Biogas Plants through Supplement Additions

Additives can improve the efficiency of anaerobic digestion by increasing biogas production, reducing air pollution, and preventing ammonia inhibition. Biological or chemical supplementation can also improve the economic efficiency of anaerobic digestion. However, the effects of specific additives on biogas production can vary, depending on the type of supplement used. This research utilizes the additives on an industrial scale and monitors the optimization of the anaerobic digestion operating parameters after their addition. The various AD additives were examined in a sufficient cycle of operation for three biogas plants located in northern Greece. In this manner, the effectiveness was investigated in multiple initial feeds and unstable operating situations caused by the seasonality of specific feedstocks. The existing operation state in the three biogas plants was recorded before and after adding the supplements. The addition of zeolite contributed to the reduction in the total ammoniacal nitrogen values in BG01 and BG03 plants. 8.4 tn of zeolite were added to the BG01 and BG03 plants over a period of two months. Low levels of trace element concentrations were observed in the BG02 plant; this issue was addressed by adding 5 kg of a trace element mixture every week over a period of 60 days. Introducing additives proved to be a stabilization factor in AD performance and an inhibition mediator.

Variations of PM2.5-bound elements and their associated effects during long-distance transport of dust storms: Insights from multi-sites observations

Dust storms are a significant concern because of their adverse effects on ambient air quality and human health. To investigate the evolution of dust storms during long-distance transport and its impacts on air quality and human health risks in cities along the transport pathway, we monitored the major fraction of dust (i.e., particle-bound elements) online in four cities in northern China during March 2021. Three dust events originating from the Gobi Desert of North China and Mongolia and the Taklimakan Desert of Northwest China were captured. We investigated the source regions of dust storms using daily multi-sensor absorbing aerosol index products, backward trajectories, and specific element ratios, identified and quantified sources of particle-bound elements using Positive Matrix Factorization model, and calculated the carcinogenic and non-carcinogenic risks of elements using a health risk assessment model. Our results indicated that under the influence of dust storms, mass concentrations of crustal elements increased up to dozens of times in cities near the dust source and up to ten times in cities farther from the source. In contrast, anthropogenic elements increased less or even decreased, depending on the relative contributions of the increase caused by accumulation of dust itself and entrainment along the transport path and the decrease caused by dilution of high wind speeds. Si/Fe ratio was found to be a valuable indicator for characterizing the attenuation of the amount of dust along its transport pathways, especially for the case originated from northern source regions. This study highlights the significant role of source regions, intensity and attenuation rates of dust storms, and wind speeds in determining the increased levels of element concentrations during dust storms and its associated impacts on downwind areas. Furthermore, non-carcinogenic risks of particle-bound elements increased at all sites during dust events, emphasizing the importance of personal exposure protection during dust storms.

Fe Element Analysis in the Spleen Tissue by Using EDS and ICP-MS after Aminated Silica Shelled Magnetite (Fe₃O₄) Administered to the Tail Vein of Mice

The suppression of cytokine storm in severe coronavirus disease 2019 (COVID-19) patients can be treated with monoclonal antibody therapy against CD3 for T cell receptor inhibition. An optimized liquid phase as a CD3 antibody-magnetic nanoparticle (Ab-MNP) conjugate can inhibit the overactivation of T cells. We aim to analyze the distribution of Fe in the spleen after acute administration of silica-conjugated amine magnetite (Fe₃O₄) nanoparticles (35 nm) delivered by intravenous injection. The Fe element distribution and concentration levels in spleen tissue were analyzed using energy dispersive spectroscopy (EDS) and inductively coupled plasmamass spectrometry (ICP-MS). The experimental result is a difference in the concentration of Fe elements, which was 1.89×10³ mg/kg in the spleen of a control mouse not administered with MNPs, whereas increases significantly to 1.93×10³ mg/kg in that of a mouse administered with MNPs. Further, time kinetic analysis of biochemical and immunological parameters is required to confirm its suitability in bio-administration.

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.

Spatial Distribution, Ecological Risk Assessment and Source Analysis of Heavy Metals Pollution in Urban Lake Sediments of Huaihe River Basin.

Heavy metals in freshwater lake sediments often exist in various chemical forms. However, the investigation and evaluation of heavy-metal elements in the sediments of the study area have not been reported, and there is a lack of objective understanding of the concentration level of heavy-metal elements. Therefore, this study is the first to report the concentrations, sources, and potential ecological risks of heavy metals in the sediments of Chengdong Lake and Chengxi Lake in Huoqiu County, Anhui Province, China. The spatial distribution, pollution characteristics, potential pollution sources, and ecological risks of heavy metals in the sediments of Chengxi Lake and Chengdong Lake of Huoqiu City in the middle section of Huaihe River in Anhui Province, China have not been reported. In this study, the sediment samples of the two Lakes were collected systematically, and the concentrations of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) were determined. The potential sources of heavy-metal elements in sediments were quantitatively analyzed according to the principal component analysis-absolute principal component fraction-multiple linear regression (PCA-APCS-MLR) receptor model. Descriptive statistics data showed that the enrichment degree of heavy metals in Chengxi Lake was higher than that in Chengdong Lake. The geo-accumulation index (Igeo) and pollution load index (PLI) indicated that there was moderate pollution for Cu, As, Hg, Ni, and Zn. The calculation results of the potential ecological risk index (Er) of the two lakes indicated that Cd (Er,max = 92.22, n = 60) and Hg (Er,max = 64.39, n = 60) showed a certain potential ecological risk in a small amount of sediment, while other heavy metals were classified as low risk. The mean sediment quality guideline quotient indicated that there was a moderate degree of potential adverse biological toxicity in lake sediments. Spatially, the seriously polluted contamination zones were the central position of Chengxi Lake and the northeast end of Chengdong Lake. The PCA-APCS-MLR receptor model revealed that Cr, Ni, Cu, and Zn were mainly from natural sources while Cd, As, Hg, and Pb elements were mainly from industrial sources and pesticide sources.

Trace element accumulation in different edible fish species from the Bolivian Amazon and the risk for human consumption

Artisanal mining and erosion of metalbearing soils can contaminate aquatic ecosystems and affect the health of riparian human populations, through metal bio-accumulation processes and fish consumption. Concentrations of eight trace metals (Cd, Cr, Co, Cu, Pb, Hg, Ni, Zn) and a metalloid (As) were measured in the muscle tissue of different edible fish species collected from markets of two cities along the Beni River banks, in the Bolivian Amazon. Relationships between the size of fish belonging to different trophic levels (carnivores, omnivores, detritivores and herbivorous) from four different fishing zones were analyzed. The most relevant results corresponded to the detritivore group, whose members exhibited significant positive correlations between the fish size and the concentration of three metals (cadmium, cobalt and nickel).Furthermore, a 3 × 3 scenario-risk analysis was performed to assess local risk for human health. This was done by relating three different scenarios of local fish consumption collected from literature (maximum, average and minimum) and three different levels of trace element concentrations (95th, 50th and 5th percentile) derived from the present study and the Minimal Risk Levels suggested by the Agency for Toxic Substances and Disease Registry. Results of these calculations determined the amount of fish muscle per contaminant that could be consumed per day without risking human’s health. Finally, Target Hazard Quotients were calculated for each trace element, aiming to indicate the potential exposure to each one and the concentration at which no adverse effects are expected.The obtained results made clear that mercury is the only trace element that represents an important health risk to humans within the studied region, considering most of the combinations in the 3 × 3 analysis. Chronic mercury intoxication could occur when consumption of fish in Riberalta or Rurrenabaque exceeded 83 g/day in females and 110 g/day in males.

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.

Metallic Composition Analysis of Crude Petroleum from Some Oil Fields in Ghana

Qualitative and quantitative analyses of chemical elements in crude petroleum using energy-dispersive X-ray fluorescence spectroscopic technique has attracted the attention of scientific world because it is fast, cheap, non-destructive and assurance in quality compared to other methods. Metallic element characterisation of crude petroleum is important in the petrochemical industry because it determines rock reservoir properties, the technology needed for extraction and refinery process, hence an exciting field that calls for research. X-ray fluorescence method was used for metallic composition analysis of four rundown crude petroleum samples (SB-2, SB-4, TB-2 and TB-1) from three oil fields (Saltpond, TEN and Jubilee). It was conducted at the National Nuclear Research Institute of Ghana. Analysis of the four samples concluded that oil field maturity decreases orderly from Saltpond, Jubilee and TEN. Vanadium-nickel ratios for each crude petroleum sample was less than 0.5, indicating that both Saltpond and Tano sedimentary rocks are of marine organic origin. Higher concentration levels of rare earth metal elements (scandium and yttrium) in the Saltpond sedimentary basin compared to Tano sedimentary rock suggest seismic effect of McCarthy Hills on Saltpond Basin. The strong negative correlation between the vanadium-nickel ratio (predictor) and scandium concentration (dependent) among the three oil fields implies that scandium concentration can equally be used to characterise the oil fields just as the vanadium-nickel ratios.

Multivariate statistical evaluation of heavy metals in the urine of opium individuals in comparison with healthy people in Western Iran

The current study aimed to evaluate the levels of some toxic and essential elements (Pb, Cd, Cu, Ti, Ni, Cr, Co, Fe, Ca, Hg, Mn, Se, and Zn) in the urine of opium-addicted compared to non-addicted cases. In this study, 126 participants were recruited and their fasting urine samples were collected (63 opium-addicted and 63 non-addicted subjects served as the reference group). ICP-MS was utilized to detect the concentration of trace elements. Results exhibited that the concentration of all elements than Ni, Cu, and Zn was markedly different between the addicted and non-addicted groups. Compared to controls, the Cd, Cr, Co, Hg, Mn, Pb, Se, and Ti levels were higher among opium-addicted cases (p < 0.05) whereas the Fe and Ca concentrations were higher among controls (p < 0.05). Robust regression analysis showed no statistically significant effect of gender on element levels. It revealed that age was associated with the levels of Ni and Cu only and also the route of administration was related to the urinary levels of Co, Cr, Hg, and Mn. In conclusion, results confirmed that it is opium consumption that affects the concentration levels of most elements.

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 heavy metal concentration in ipomoea batatas and spinach consumed in Zanzibar by Energy Dispersive X-ray Fluorescence (EDXRF)

This work aimed to assess the levels of heavy metal concentration in ipomoea batatas and spinach associated with uncontrolled municipal waste, motor vehicles fumes, pesticides and fertilizer in the urban west region, in Zanzibar. Twenty samples were randomly collected in local markets and three farms located along a roadside in the urban west region. The samples were analysed using an energy dispersive X-ray fluorescence method at Tanzania Atomic Energy Commission in Arusha. Essential and toxic elements: Mn, Cu, Fe, As, Zn, Pb, and Ni were detected in both ipomoea batatas and spinach. Ipomoea batatas was found to have a higher concentration of Cr, Fe, Cd and Zn while spinach had a higher concentration of Ni, Cr and Zn. The essential elements concentrations of vegetables analysed in the current study were found within safety baseline levels for human consumption. However, the concentration levels of toxic elements were above FAO/WHO permissible limits. The higher concentration levels of toxic elements in ipomoea batatas and spinach might be associated with contamination of municipal waste, chicken manure, motor vehicles fumes or pesticides. Therefore, vegetable cultivation along a roadside in the urban west region in Zanzibar and the use of fertilizer and chicken manure in vegetables introducing high levels of heavy metals in the food chain.

Characterization and source apportionment of airborne particulate elements in the Athabasca oil sands region

The oil sands industries in Alberta, Canada are potential sources of particulate-bound elements in the region. This study explored the ambient concentrations and size distributions, and conducted source apportionment of 48 particulate elements, based on samples collected in 2016–2017 at four air monitoring sites in the Athabasca oil sands region: Fort McKay (AMS1), Buffalo Viewpoint (AMS4), Wapasu Creek (AMS17), and Stoney Mountain (AMS18). Element concentrations in fine and coarse particulate matter (PM2.5 and PM2.5–10 respectively) at the four sites were generally lower than their typical concentrations at other urban and industrial sites in North America. Among all elements, S was the most abundant in PM2.5 with mean concentrations ranging from 189 ng/m3 (AMS18) to 284 ng/m3 (AMS1). Of the trace, toxic elements in PM2.5, Zn was the most abundant with mean concentrations ranging from 3.43 ng/m3 (AMS18) to 5.37 ng/m3 (AMS4). Positive Matrix Factorization (PMF) modeling of the element concentrations in PM2.5 was used for source apportionment for Zone1 (including AMS 1, 4, and 17, situated closer to industrial activities) and for Zone2 (including AMS18, a background site). The sources of elements for Zone1, included crustal dust, bitumen processing, haul road dust, and biomass burning that explained ~33%, ~43%, ~15%, and ~9% of the total resolved elemental mass, respectively. The sources of elements for Zone2, included Pb-rich source, biomass burning, fugitive oil sands, crustal dust, and bitumen processing explaining ~8%, ~7%, ~3%, ~22%, and ~60% of the total resolved elemental mass, respectively. Elemental mass concentrations of the bitumen processing source factor at Zone2 was two-thirds of that in Zone1. Overall, mass proportions of the bitumen processing source factor at all four sites were significant, suggesting that the oil sands industries played a key role in ambient element concentration levels in the region.

Determination of chemical elements in rice from Singapore markets: Distribution, estimated intake and differentiation of rice varieties

Concentrations of As, Cd, Co, Cu, Mn, Pb, Se and Zn were determined in polished and husked rice samples purchased from Singapore markets to estimate nutritional risk by their estimated weekly intakes (EWIs). The elemental distribution in rice grain was studied using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS), and a principal component analysis was performed to investigate the relationships between the variables (total element concentration) in a multidimensional space. Except for Cd and Se, the median concentration of analytes for husked grains was higher than in polished grains. Rice samples with As concentration higher than 198 μg kg−1 were submitted to speciation analysis, and inorganic-As found in grains ranged from 41 to 87 % of the total As. Calculated EWIs for essential elements were lower than the Recommended Dietary Allowance, while the EWIs for non-essential elements were below the Provisional Tolerable Weekly Intake. Nevertheless, our results demonstrate that the presence of toxic elements in rice, especially As, must be carefully monitored. It was found a significantly low concentration levels of essential elements in most of the samples analyzed, highlighting the relevance of biofortification strategies to mitigate hidden hunger. Furthermore, the mineral profile obtained from the samples allowed discrimination of rice samples according to farming practice, grain processing and country of origin using principal component analysis and discriminant function analysis.