Mean Concentrations Of Trace Elements Research Articles

Selected trace element concentrations in run-of-mine coal, discard, and coal product, and environmental implications

The concentrations of selected trace elements (As, Cd, Hg, and Pb in run-of-mine (ROM) coal, discard, and coal product were investigated to assess the efficiency of beneficiation in reducing trace element concentrations and ascertain any implications regarding environmental compliance to regulatory frameworks. Samples were collected from a colliery in Mpumalanga Province twice a month for a period of 24 months. The samples were ashed to approximately 0.21 mm, then digested in a mixture of 70% HNO3 and 40% HF and analysed using inductively coupled plasma-mass spectrometry (ICP-MS). Except for Pb, the mean concentration of all elements decreased from the ROM stage to the coal product stage. The order in which trace elements occurred from the highest to lowest throughout the production chain was Pb>As>Hg>Cd. With the exception of Cd, the mean trace element concentrations in the discard were above the total concentration threshold (TCT) set for landfill disposal. The As, Hg, and Cd concentrations in the product were well below the thresholds for all land uses. However, Pb concentrations in the product coal were above legal limits, which is of concern with regard to environmental compliance and the performance and marketability of the product.

Concentration, seasonality, and sources of trace elements in atmospheric aerosols from Godavari in the southern Himalayas

Atmospheric pollution has detrimental effects on human health and ecosystems. The southern region of the Himalayas, undergoing rapid urbanization and intense human activities, faces poor air quality marked by high aerosol loadings. In this study, we conducted a two-year PM10 sampling in the suburban area (Godavari) of Kathmandu, a representative metropolis situated in the southern part of the central Himalayas. The trace elements were measured to depict aerosol-bound element loadings, seasonality, and potential sources. The mean concentrations of trace elements varied considerably, ranging from 0.27 ± 0.19 ng m−3 for Tl to 1252.78 ng m−3 for Zn. The average concentration of Co and Ni was 1.2 and 22.4 times higher, respectively, than those in Lhasa city in Tibet in the northern Himalayas. The concentration of Pb was 38 times lower than that in Lahore, Pakistan, and 9 times lower than urban sites in India. For the seasonality, the trace element concentrations displayed remarkable variation, with higher concentrations during the non-monsoon seasons and lower concentrations during the monsoon season. This trend was primarily influenced by anthropogenic activities such as low-grade fuel combustion in vehicles, coal combustion in brick kilns, and biomass burning, along with seasonal rainfall that induced aerosol washout. The enrichment factors (EFs) analysis revealed that Cd, Zn, Sb, Ni, Cu, Cr, and Pb had higher EFs, indicating their significant contributions from anthropogenic sources. In contrast, elements like Tl, Co, V, Cs, U, Ba, Th, and Sr, characterized by lower EFs, were mainly associated with natural sources. The Pb isotopic ratio profiles exhibited the Pb in PM10 are derived major contribution from legacy lead. Biomass burning contributed to the Pb source in winter. These findings provide policymakers with valuable insights to develop guidelines and strategies aimed at improving air quality and mitigating the impact of aerosol pollution on human health in the Himalayan region.

Assessment of trace elements in the long-term banana cultivation field’s soil

This work assesses the contamination of trace elements (Cr, Cu, Ni, As, Zn Cd, Mn, Fe, and Pb) in soil and different tissues of the banana plant (Musa spp.), the ecological risks of trace elements using various indices, and the probable health risks using a chemometric approach. Soil and different banana plant tissues were collected from banana fields around the industrial area of the capital of old Pundranagar (the earliest urban archaeological location), Bangladesh. Samples were digested by acid digestion, and trace elements were measured by inductively coupled plasma spectrophotometer (ICP-MS). The concentrations of Cr, Ni, Cu, As, Cd, Pb, Fe, Mn, and Zn in soil ranged from 1.50–61.7, 2.42–87.4, 2.00–100.8, 0.25–31.2, 0.10–12.7, 0.60–91.8, 11330–23782, 8.69–105.9, and 7.50–125.9 mg/kg, respectively. The mean concentrations of trace elements in four tissues descend in order of roots > leaves > stems > fruits. The abundances of trace elements varied in both soil and plant samples, which apparently occurred due to the variations of soil parent materials and the excessive use of agrochemicals for long-term banana cultivation. The soil exhibited a moderate to high degree of contamination with trace elements, and Cr, Pb, Zn, Cd, and As mainly originated from anthropogenic sources. Both non-cancer and cancer risks were perceived due to Cr and As exposure from the fruit tissue of banana plants in the study area.

A holistic approach to the eco-geochemical risk assessment of trace elements in the estuarine sediments of the Southeastern Black Sea

The estuarine sediments were sampled seasonally along the southeast coast of the Black Sea, to assess the concentrations, sources, distributions, and possible ecological risks of trace elements (TEs). The mean concentrations of TEs (mg/kg) were ranked as Fe (56,659.83) > Al (39,758.00) > Mn (1168.53) > Zn (155.03) > Cr (120.75) > Pb (93.71) > Cu (82.66) > Ni (44.93) > Co (17.98) > As (13.66) > Cd (0.99) > Hg (0.18), respectively. The stations S4 and S6 showed “very high contamination” for Pb, “significantly enrichment” for Pb and Cd, “high ecological risk” for Cd, and “heavily polluted” for Pb and Cd according to the results of CF, EF, Eri, Igeo, respectively. The rest of the stations were in the low or moderate contamination through the all seasons as assessed by different eco-geochemical risk assessment indices. The integrated risk evaluation indices indicated no contamination in stations S3 and S5.

Physicochemical properties of water in an intensive agricultural region in Bangladesh: a preliminary study for water quality and health risk assessment

ABSTRACT There are many reservoirs, ponds and Korotoa River in the capital of ancient Pundranagar, Bangladesh, which is an intensive agricultural region. Since different industries are operated for the preparation of different agricultural instruments and agrochemicals are extensively applied to the agricultural soils which mix with the river and pond water and these water bodies may be contaminated with trace elements. In this study, levels of nine trace elements (Cr, As, Cu, Ni, Zn, Cd, Fe, Mn and Pb) and physicochemical properties in surface water from one river and five ponds were measured and compared with water quality guidelines. In addition, health risks, pollution status and possible sources of trace elements were assessed. The mean concentrations of As, Cd, Pb, Cr, Ni, Cu, Fe, Mn and Zn in pond water were 0.059, 0.033, 0.067, 0.136, 0.133, 0.280, 0.733, 0.127 and 0.266 mg/L and river water were 0.055, 0.037, 0.054, 0.104, 0.120, 0.230, 0.702, 0.125 and 0.200 mg/L, respectively. Except Cu and Zn, the mean concentrations of trace elements were above the water quality permissible standards indicating water from these sources is not safe for human use. The WQI values suggested that the water quality is excellent to poor water quality class. Health risk indices indicated that As in water via ingestion exposure pathway may pose both non-carcinogenic and carcinogenic health risks to the residents where the non-carcinogenic risk to the residents is raised from ingestion of As, Cd, Cr and Pb from water.

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

Spatial trace element bioaccumulation along with consumer risk simulations of Mediterranean mussels in coastal waters of Turkey.

Turkey borders three seas and the most populous locations are squeezed into the coastal territories. Thus, organisms living in these aquatic territories are under longstanding anthropogenic pressure. Hence, this study investigated the consumption outcomes leading to potential child and adult health risks along with the spatial distribution of As, Cd, Cr, Cu, Ni, Pb, V, and Zn in the Mediterranean mussels (Mytilus galloprovincialis) sampled at 23 different stations from the Black Sea, the Sea of Marmara, and the Aegean Sea coastal waters of Turkey. The mean concentrations of trace elements found in the Mediterranean mussels followed Zn (39.75 mg kg-1) > Cu (1.95 mg kg-1) > As (1.84 mg kg-1) > Pb (0.99 mg kg-1) > Ni (0.65 mg kg-1) > Cr (0.62 mg kg-1) > V (0.47 mg kg-1) > Cd (0.08 mg kg-1). Factor analysis revealed that trace elements were mostly derived from anthropogenic sources. Pb values were found to be above the permissible European Union limits at 10 sampling stations. While the estimated weekly intake did not exceed the Joint FAO/WHO Expert Committee on Food Additives limits, the target hazard quotient for As was found >1 for children. The lifetime cancer risk (CR) for adults and children was unacceptable (>10-4) at high consumption rates for As according to US Environmental Protection Agency. Monte Carlo simulation confirmed a CR to adult (62.98%) and children (97.24%) mussel consumers caused by As.

Monitoring spatially resolved trace elements in polar bear hair using single spot laser ablation ICP-MS

Elements and compounds circulating in the body are incorporated into hair as it grows. Because of this, hair analyses are increasingly being incorporated in investigations of temporal trends in e.g. hormones and diet in wildlife species such as polar bears (Ursus maritimus).For this study, guard hair (GH; mean length 62 mm) and foreleg guard hair (FGH; mean length 164 mm) were collected from 15 adult male polar bears in western Hudson Bay, Canada. Our aim was to quantify the trace elements arsenic (As), cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), mercury (Hg), selenium (Se), strontium (Sr), and zinc (Zn) every 3 mm in GH and FGH using laser ablation inductively coupled plasma mass spectrometry (laser ablation ICP-MS).Quantitative data was obtained at spatial scales as small as 50 μm – the smallest laser spot diameter used. Mean trace element concentrations increased in the order Pb < As < Cd < Se < Hg < Cu < Sr < Fe < Zn for both GH and FGH (pooled across all individuals). However, mean trace element concentrations were all significantly different between GH and FGH, except for Hg. Hg concentration varied along the length of both GH and FGH; each bear exhibited a unique pattern in Hg variation along the hair. For the remaining eight trace elements, the most common pattern was that of smaller fluctuations near the base of the hair, followed by an increase towards the tip. These fluctuations in trace element concentrations were likley related to hair growth and temporal changes. In this pilot study, we found quantifying trace elements in polar bear hair using laser ablation ICP-MS to be a promising monitoring technique across multiple temporal scales.

Trace element concentrations in fine sediment and linkages to non-point pollution source: Lower Johor river basin

Johor Strait is an economically important freshwater system in the southern portion of Peninsular Malaysia. In past decades, Johor has been experiencing rapid developments especially in industrialisation, urbanisation and agricultural activities which have impacted the quality of Johor river. This study focused on identifying the intensity and degree of sediment contamination by trace elements from different anthropogenic sources using the multiple Risk Indexes. Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was used to detect trace element concentrations from nine sampling stations. The overall ranges for metals are 0.35-4.25, 505.86-1864.56, below detection limit (BDL)-5.37, 0.02-0.07, 0.02-0.17, 0.59-2.05, BDL-5.35, 247.07-1010.23, 0.71-9.62, 1.08-5.68 and 10.87-21.15 mg/kg for Ag, Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, and Zn respectively. The mean concentrations of trace elements follow the order: Al > Fe > Zn > Cu > Mn > Ni > Ag > Cr > As > Co > Cd. In this study, high concentrations of most elements (Al, As, Cd, Co, Fe, Mn, and Ni) were recorded at SS5 as the station is located near the Kota Tinggi city. Comparison with the sediment quality guidelines (SQGs) portrayed that concentrations of As, Cd, Cr, Cu, Ni, and Zn were below the Threshold Effects Level (TEL), Severity Effects Level (SEL), Probable Effects level (PEL) values in all sampling stations. The Pollution Load Index (PLI) that ranged between 0.151 and 0.389 (PL1 < 1) indicates that the Johor river sediments are free of trace element contamination. Potential Ecological Risk Index (RI), and Potential Ecological Risk Factor (Er) were in the range of 3.018-11.823 (RI < 150) and 0.103-7.141 (Er <40) respectively, which indicate that trace elements in Johor river pose no adverse effects on aquatic biota. The Pearson’s correlation matrix showed a good positive correlation between Al and As (0.546), Co (0.595), Fe (0.440), Mn (0.770), and Ni (0.496), representing similar sources of pollution. The cluster analysis indicates that Al, Mn, As, Ni, Fe, Cd, and Co originated from natural processes while Cr, C, Ag, and Zn are mainly from anthropogenic sources. Suggesting that man-made activities are accelerating sedimentation rate and washing down the pollutants together to the adjacent water bodies. Tracing the origin of the elements and planning for target mitigation to reduce further deterioration to the receiving river system could be the next mode of action.

Sources and behavior of trace elements in groundwater in the South Eastern Desert, Egypt.

Due to water scarcity, the groundwater will represent an essential source of water in many communities worldwide. This study was carried out to investigate the main hydrogeochemical characteristic of trace elements composition, their sources, and its vulnerability in groundwater to the human population. Fifteen groundwater samples were collected from boreholes and hand dug wells from the South Eastern Desert, Egypt, and analyzed for Al, As, B, Fe, Mn, Cd, Co, Cr, Cu, Hg, Ni, Pb, Rb, Sb, Sr, Th, U, V, and Zn using inductively coupled plasma mass spectrometry. Multivariate analyses were applied to identify the distribution and potential source of trace elements. The groundwater is tapped from the Miocene and the fractured basement rock aquifers. The mean concentrations of trace elements exceed the guideline values of all organizations, except in some wells for Zn, Cu, and Co. Cationic trace elements declined in the order of Mn > Fe > Zn > Al > V > Ni > Rb > Sr > U > Cu > Cr > Co > Cd > Pb > Th > Sb > Hg. Oxyanions As (mean 15.48 mg/L) and B (mean 1.24 mg/L) showed very high concentrations and higher than the average WHO concentrations in water suggesting potential adverse toxicity to all aquatic organisms. Five factor analyses indicated that different geochemical contributions are involved in the chemical characteristics of groundwater in the study area. Water-rock interaction and dissolution processes in bed rocks from different coastal Miocene deposits, meta-volcanics, basic-ultrabasic rocks, granitic and meta-sediments, seawater intrusion, residential wastes, and mining activities, in addition to the pH/Eh conditions, adsorption, and surface complexation during the chemical weathering are the main factors influence the trace elements distribution in groundwater. Results from this study for the six different groundwater aquifers are a unique insight into the sources and mobility of the observed trace elements in the groundwater and can be used in the assessment of contamination for drinking water wells. The association of trace elements from different aquifers might be useful in tracers studies of water-rock interaction. Due to the enrichment of trace elements in nearshore and crystalline groundwater aquifers in the study area and in similar areas worldwide, treatment technologies, and sustainable water management processes should be applied to prevent severe risks to the communities.

Hydrogeochemical processes and trace elements in sediments at the south-eastern Mexican karst aquifer

The chemical characteristics and hydrogeochemical processes that govern the groundwater in the sinkholes ring of the Yucatan Peninsula were assessed. The groundwater of the area studied is of the Ca–Mg–HCO3 type. Local geology (abundance of dolomite) determines Mg2+ enrichment relative to Ca2+. The absence of seawater intrusion was established. Sinkhole water chemistry is controlled by carbonate rock dissolution, with dominance of Ca2+, Mg2+ and HCO3–. The dynamic and controlling factors of trace elements were determined in sediments of the southern part of Mexico. The order of mean concentrations of trace elements in sediments is Sr&amp;gt;Pb&amp;gt;Cu&amp;gt;Zn&amp;gt;Cr&amp;gt;&amp;gt; Cd. With regard to the sequential extraction procedure, the potential importance of fractions in sediments is in the order residual&amp;gt;organic matter&amp;gt;carbonates&amp;gt;exchangeable&amp;gt;water soluble, confirming that sinkhole sediments works as a sink of trace elements, and that no anthropogenic pressure exists in the groundwater of the hydrogeological reserve area. Trace element stability in sediments decreased as follow: Cd&amp;gt;Pb&amp;gt;Zn&amp;gt;Cr&amp;gt;Cu&amp;gt;Sr. The study results describe the groundwater and sediment condition of the hydrogeological reserve area, and provide insights for stakeholders and authorities. Growing population and economic activities may be major threats to the groundwater in coming decades.

Trace element contaminant uptake in phytocap vegetation and implications for koala habitat, Lismore, Australia.

Phytocapping is increasingly regarded as an economical and environmentally sustainable post-closure landfill management strategy. During 2013, a phytocap comprised of koala habitat trees was established on a historic landfill site in Lismore as part of an Australian trial program (A-ACAP). This case study was conducted to determine trace element contamination of the Lismore phytocap soil and foliage, and identify risks to grazing koalas. Foliage of Eucalyptus tereticornis, a key koala food tree, and Acacia melanoxylon, a reference native species, were assessed at the phytocap and an uncontaminated reference site. Concentrations of Ag, As, Hg and Pb were significantly higher in foliage from the phytocap compared to that from the reference site (p < 0.0001df 7, 52). Mean trace element concentrations in phytocap E. tereticornis foliage were compliant with state and international standards for contaminants in food and animal feed (NSW State Government, 2010; WHO and FAO, 2015) and soil was compliant with national health-based investigation levels for contaminated sites (NEPC, 2011). However, contaminant distribution was not homogenous, and As and Pb concentrations exceeded guidelines in some soil and foliage samples. Based on available guidelines and weekly dietary intake calculations, risks to koala health posed by trace element contamination of phytocap foliage are currently low, though should be managed by continued monitoring as the vegetation matures.

The Influence of Waste Disposal Site on The Water and Soil Quality in Halabja Province, Kurdistan, Iraq

Solid waste disposal could be a major environmental problem in in Kurdistan region of Iraq because it is not managed properly. The main purpose of this study was to assess the influence of long term solid waste disposal on water and soil physicochemical properties. Soil and water samples were collected in and around the solid waste disposal area. The samples were analyzed for physicochemical characteristics and potentially toxic elements using ICPMS. The results revealed that some water parameters analysed well below WHO and EU standards for drinking water. Therefore, the surface and ground water samples in this study are good for drinking purposes. However, the application of water quality index (WQI) suggests that the ground and surface water around the open dumpsite are marked as good and poor water in quality respectively. High concentration of Ca in all soil samples is expected because the regional geology is calcareous. The concentrations of PTEs were found in order of Mn&gt; Fe&gt; Ni&gt; Zn&gt; Cr&gt; Cu&gt; Pb&gt; Se&gt; Cd. Although relatively high concentrations of Ni and Cr were found at all sampling points, mean concentrations of trace elements in the soil samples in the studied area were all below the soil guideline values (SGV). Enrichment factors (EFs), calculated using typical carbonate bedrock geologies, confirmed that there was typically significant enrichment in trace elements above expected background concentrations. Whereas concentrations of toxic elements were within the ‘safe’ limits in the studied agricultural areas, care should be taken because prolonged disposing of wastes in the outskirt of the city could lead to PTE accumulation in surrounding water soils.

Human health risk assessment of trace elements in shallow groundwater of the Linhuan coal-mining district, Northern Anhui Province, China

ABSTRACTEnrichment of trace elements in groundwater poses considerable risks to human health. The concentrations of seven trace elements (Cr, Mn, Ni, Cu, Zn, Cd, and Pb) in 34 samples of shallow groundwater from the study area were estimated. We assessed the concentrations of the trace elements and health risks with statistical analysis and the US Environment Protection Agency (USEPA) model. The results showed that the mean concentrations of trace elements decreased as follows: Mn > Zn > Ni > Cr > Cu > Cd > Pb. Apart from Mn at one sampling point, the concentrations of all trace elements were below the guideline values of the World Health Organization for drinking water. Correlation and cluster analysis indicated that the trace elements fell into groups, with Ni and Cu in one group, and Mn, Zn, and Cd in another, which suggested that the trace elements grouped together had similar sources. The total non-carcinogenic risk values ranged from 8.52 × 10−4 to 1.27 × 10−1. The total carcinogenic risk caused by Cr and Cd averaged 1.62 × 10−6, which exceeded the acceptable level of 1 × 10−6 recommended by the USEPA. The carcinogenic risk of Cr accounted for 75.93% of Rtotal.

Transient deep-water oxygenation in the early Cambrian Nanhua Basin, South China

Many late Neoproterozoic to early Cambrian fossils of multicellular eukaryotes, including those of benthic animals, are found preserved under anoxic and even euxinic bottom-water conditions, which is contradictory to the consensus that oxygen is essential to eukaryotes. To investigate this conundrum, we conducted an integrated study of iron speciation, redox-sensitive trace elements, and Mo isotopes (δ98Mo) on the black shale interval of the lower Cambrian Hetang Formation (∼535–521Ma) at Lantian, South China, in which benthic sponge fossils are abundant in the lower member (LM) but absent in the upper member (UM). Iron speciation data point to uniformly anoxic-ferruginous conditions in the LM and euxinic conditions in the UM, whereas the trace-element and δ98Mo data show greater secular variation in redox conditions. The LM shows higher mean trace element concentrations (Mo: 108ppm, U: 36ppm, V: 791ppm) and lower and more variable δ98Mo (+0.13 to +1.76‰) relative to the UM (Mo: 45ppm, U: 18ppm, V: 265ppm, δ98Mo: +1.59 to +1.67‰), and ratios of redox-sensitive trace element concentrations to total organic carbon are significantly more variable and higher on average in the LM relative to the UM. The appearance of sponge fossils and lower δ98Mo values correlate strongly with gray (i.e., lighter-colored) layers in the LM. These patterns can best be interpreted as recording mainly euxinic conditions throughout deposition of the study units, with more intense background euxinia in the LM relative to the UM, but also with frequent transient oxygenation events in the LM that do not appear in the UM. The transient oxygenation events of the LM led to the initial colonization of the deep Nanhua Basin by sponges, and the termination of these events in the UM caused sponge faunas to disappear until a general rise in O2 levels later in the Cambrian permitted their return to deeper-water habitats. Our study also illustrates that multiple geochemical and paleobiological proxies exhibit different responses in ‘poikiloredox’ environments (i.e., characterized by small-scale spatial and high-frequency temporal variations), which can lead to apparent contradictions between metazoan fossil occurrences and their inferred watermass redox conditions.

Assessment of Air Pollution around the Panzhihua V-Ti Magnetite Mine Region, Southwest China

This study investigated variations in air quality by evaluating trace gases, inhalable particulate matter (PM_(10)), and associated trace elements at three sites in Panzhihua (a mining city located in Panxi Rift Valley, Southwest China) between January and December 2014. The concentrations of 19 trace elements in PM_(10) were determined through inductively coupled plasma mass spectrometry. Single particle morphology and chemical composition were determined through scanning electron microscopy with energy-dispersive X-ray analysis to identify their possible sources. Mean sulfur dioxide, nitrogen dioxide, and carbon monoxide concentrations were highest near the steel smelting district, whereas ozone concentrations were highest in the residential region. Annual mean concentrations of PM_(10) at three sites were 129.4, 165.5, and 187.2 μg m^(-3); all these exceed the annual mean (70.0 μg m^(-3)) of the National Ambient Air Quality Standard. In addition, the concentrations of trace elements in PM_(10) exhibited significant spatial and seasonal variations at the three sites. The mean concentrations of trace elements in PM_(10) were in the order of Fe ＞ Ti ＞ Zn ＞ Pb ＞ Cu ＞ Mn ＞ Ba ＞ V ＞ Cr ＞ Ni ＞ Sr ＞ Bi ＞ Cd ＞ As ＞ Co ＞ Sb ＞ Sc ＞ TI ＞ U. The enrichment factor values of the trace elements suggested that anthropogenic activities were the dominant sources of As, Cd, Sb, Ti, TI, Zn, Cu, Pb, and Bi. Particle morphology and chemical composition analysis revealed five major particle types, namely aluminosilicate, Fe-containing, mineral, soot, and Ca-containing particles.

Bioaccumulation of metals in silver carp and stone moroko from Zarivar Wetland in Kurdistan Province, Iran

This research aims to monitor the trace elements content (Cr, Cu, Pb, Cd, Ag, Al, Mn, Mg, Zn and Fe) in the tissues of the muscle and liver of silver carp (H. molitrix ) and stone moroko (P. parva) from Zarivar Wetland in western Iran. This research was cross-sectional. The research specimen was fish caught from Zarivar Wetland. Metal concentration analysis was carried out utilizing an ICP. Findings indicate presence of Fe and Pb in the liver, Zn and Cd in the muscle hadthe highest and lowest metal concentration accumulated, respectively. The trace elements content in the liver tissue was higher than those in the muscle tissue of H. molitrix and P. parva. Moreover, the Hazard Quotients for an adult with mean of 71.5 kg was below 1 based on trace elements levels. Though, the mean concentrations of trace elements in the muscle of H. molitrix and P. parva was lower than international standards. according to the uptake and distribution, these elements require periodic monitoring in the human body.

Trace Element Accumulation and Tissue Distribution in the Purpleback Flying Squid Sthenoteuthis oualaniensis from the Central and Southern South China Sea.

Sthenoteuthis oualaniensis is a species of cephalopod that is becoming economically important in the South China Sea. As, Cd, Cr, Cu, Hg, Pb, and Zn concentrations were determined in the mantle, arms, and digestive gland of S. oualaniensis from 31 oceanographic survey stations in the central and southern South China Sea. Intraspecific and interspecific comparisons with previous studies were made. Mean concentrations of trace elements analyzed in arms and mantle were in the following orders: Zn > Cu > Cd > Cr > As > Hg. In digestive gland, the concentrations of Cd and Cu exceed that of Zn. All the Pb concentrations were under the detected limit.

Study of road dust magnetic phases as the main carrier of potentially harmful trace elements

Mineralogical and morphological characteristics and heavy metal content of different fractions (bulk, non-magnetic fraction-NMF and magnetic fraction-MF) of road dusts from the city of Thessaloniki (Northern Greece) were investigated. Main emphasis was given on the magnetic phases extracted from these dusts. High magnetic susceptibility values were presented, whereas the MFs content of road dust samples ranged in 2.2–14.7wt.%. Thermomagnetic analyses indicated that the dominating magnetic carrier in all road dust samples was magnetite, while the presence of hematite and iron sulphides in the investigated samples cannot be excluded. SEM/EDX analyses identified two groups of ferrimagnetic particles: spherules with various surface morphologies and textures and angular/aggregate particles with elevated heavy metal contents, especially Cr. The road dusts (bulk samples) were dominated by calcium, while the mean concentrations of trace elements decreased in the order Zn>Mn>Cu>Pb>Cr>Ni>V>Sn>As >Sb>Co>Mo>W>Cd. MFs exhibited significantly higher concentrations of trace elements compared to NMFs indicating that these potentially harmful elements (PHEs) are preferentially enriched in the MFs and highly associated with the ferrimagnetic particles. Hazard Index (HI) obtained for both adults and children through exposure to bulk dust samples were lower or close to the safe level (=1). On the contrary, the HIs for the magnetic phases indicated that both children and adults are experiencing potential health risk since HI for Cr was significantly higher than safe level. Cancer risk due to road dust exposure is low.

Seasonal variation in trace element concentrations and Pb isotopic composition of airborne particulates during Asian dust and non-Asian dust periods in Daejeon, Korea

Trace element contamination (As, Cd, Cr, Co, Cu, Mo, Ni, Pb, S, Zn, and Zr) in both Asian dust (AD) and non-Asian dust (NAD) periods taken from Daejeon, Korea, in 2008 was examined, and the pollution sources were evaluated based on the Pb stable isotope. Additionally, temporal variation in the trace element concentrations of total suspended particulate matter, PM10 and PM2.5, was evaluated in 14 samples for AD and 46 samples for NAD collected from March 2007 to November 2008. Patterns showed that the monthly mean concentrations of trace elements in winter were 2–13 times higher than those in other seasons. In contrast, the monthly mean concentrations of sulfur were the highest in the summer monsoon season. Distinct temporal patterns were observed in the monthly mean concentrations of trace elements, due mainly to high coal combustion in China. These results were supported by the 206Pb/207Pb ratios of AD and NAD, which were identical or similar to those of the airborne particles in certain heavily industrialized Chinese cities and coal and coal combustion dust of China. The Pb isotopic composition in the particulate matter of NAD showed lower 206Pb/207Pb, 207Pb/204Pb, and 206Pb/204Pb ratios in the autumn, winter, and spring seasons, showing the influence of Pb from the heavily industrial cities of China, and higher values in the summer, indicating the dilution and/or mixing effect of the marine air mass from the south.