Average Element Concentrations Research Articles

Radioactivity, radiogenic heat production and environmental radiation risk of the Basement Complex rocks of Akungba-Akoko, southwestern Nigeria: insights from in situ gamma-ray spectrometry

The Basement Complex rocks of Akungba-Akoko, southwestern Nigeria, typically migmatites (M), biotite gneisses (BGN), granite gneisses (GGN), charnockites (Ch), biotite granites (BG) and pegmatites (P), were assessed using ground gamma-ray spectrometry (GRS). This study aimed at determining rocks’ radionuclides concentration, alterations, radionuclides mobilization, radiogenic heat production (RHP) rate (first report for the area) and environmental radiation risk to humans. The results of this study were integrated with previous data on the petrography and geochemistry of these rocks, for detailed interpretation. The results of average elemental and activity concentrations for Akungba-Akoko rocks, were 2.66%, 3.16 ppm and 13.98 ppm, and 831.35, 39.01 and 56.77 $$Bq{kg}^{-1}$$ for 40K, 238U and 232Th, respectively; with increasing rock order of Ch < M < GGN < BGN < P < BG. High radionuclides concentration in the rocks, with exception of charnockites, were determined by high amount of K-feldspar, plagioclase, biotite and accessory minerals—zircon and monazites. On the other hand, the low radionuclides concentration in the rocks, especially in Ch and M, were aided by the variability of the naturally occurring radioactive elements (NORMs) caused by alterations and mobilization during metamorphism and crystallization processes as suggested by radioelements composite, K/eTh ratio and F-parameter of Efimov analyses. RHP average of 2.03 $$\mu W{m}^{-3}$$ above the crustal average range of 0.8–1.2 $$\mu W{m}^{-3}$$ may have significantly contributed to the heat flux in the studied area; however, the RHP of charnockites are lower than the crustal range. The absorbed dose rate average of 87.98 $$nGy{ h}^{-1}$$ was within the permissible range, and other estimated radiological parameters, namely annual effective doses, hazard indices, gamma activity and activity utilization index, were all far below the permissible limit of 1 $$mSv {y}^{-1}$$ for these rocks. However, the annual gonad dose equivalent (618.874 $$\mu Sv{ y}^{-1}$$ ) and excess life cancer risk (1.511 × 10− 3) were above their permissible limits. Due to the high gamma radiations from the pegmatitic and biotite-rich rocks in the studied area, their high usage should be reduced. Hence, periodic monitoring of the study area is advised.

Impact of Oxides and Physiochemical Properties of Agricultural Soil on Bioaccumulation of Toxic Heavy Elements in Wheat Grains in Yaychi, Northeast of Iraq

To investigate the potential link between toxic heavy elements in soil with soil physiochemical properties and oxides, as well as their impact on the bioaccumulation of these elements in wheat grains. Agriculture soil and wheat grains were sampled from Yaychi area, Kirkuk northeast of Iraq. Soil physiochemical properties, oxides and toxic heavy elements contents were determined. The average concentration of toxic heavy elements in soil was in this order Ni&gt; Cr&gt; Pb&gt; As&gt; Cd&gt; Hg, and some of these elements had exceeded their average in earth's crust and Canadian Agricultural Soil Quality Guidelines. While in wheat grains the toxic heavy elements, contents were in the following order Cr&gt; Ni&gt; Pb&gt; As&gt; Cd&gt; Hg. The soil physiochemical properties in the study area are shown to be medium alkaline, non-saline, calcareous, non-gypsiferous, inorganic and loam texture. It became clear from the correlation matrix that the toxic heavy elements except for arsenic have significant relationships with different soil physiochemical properties and major oxides. In turn, oxides and the physiochemical properties of the soil and its type reduced the bioaccumulation of these elements in wheat grains except for arsenic, as appeared in the present study, that toxic heavy elements do not accumulate in wheat grains. And among the studied elements, arsenic had the highest bioaccumulation rate in wheat grains, because its concentration in soil has been affected by only human activities.

Inter- and intra-specific phenotypic variation of ecological stoichiometric traits in a mixed-oak secondary forest in China

Ecological stoichiometry provides a framework for the balance and flow of elements between organisms and ecosystems. Elemental phenotypes have an important influence on the environmental adaptation and ecological evolution of plants. There have been few reports on inter- and intra-specific phenotypic variations of ecological stoichiometric traits for congeneric species in a mixed forest although such variations are well- documented at the species level at global, regional and local scales. In this study, total carbon (TC), nitrogen (TN), phosphorus (TP) and potassium (TK) were measured in leaves and the elemental phenotypes were statistically analyzed in four species of oaks—Quercus fabri, Q. serrata var. glandulifera, Q. acutissima and Q. variabilis—in a mixed-oak secondary forest in Yushan, Jiangsu, China. The average element concentrations in the four oak species were not relatively higher than previously reported for oaks from world and Chinese flora. Ecological stoichiometry traits were correlated with tree height and diameter at breast height, indicating that phosphorous and potassium were positively correlated with tree size, while carbon was negatively correlated, especially the relationship between oak growth and total carbon or total phosphorus was obvious, and the study concluded that this was because plant growth depended on phosphorus storage and had opposite effects on leaf carbon accumulation. Based on tree plasticity index and the coefficient of variation, there was medium variation in element concentrations. The plasticity index of total carbon levels was the lowest, and that of potassium the highest. Principal component analysis and cluster analysis showed that the intra-specific variation among the four oak species was higher than inter-specific variation. From the perspective of nutrient supply and ecological adaptation, this study creates a foundation for the management of secondary oak forest stands.

ICP/XRF Analysis for Trace Elements in Soil Samples from Gezira and Suki Schemes, Sudan

In the present study, soil samples have been collected from two different agriculture areas: Gezira and Suki schemes in Sudan, The elemental concentrations for Cr, Ni, Cu, Zn, and Pb have been determined using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and X-ray Fluorescence spectrometry (XRF). The accuracy of measurements has been investigated by using ISE (PT) 1&amp;4 and fortified samples for ICP, IAEA-Soil-7 XRF, respectively. A good agreement was found between certified and measured values.&#x0D; The average elemental concentrations by ICP of these elements Cr, Ni, Cu, Zn, and Pb in loc1 were found as follows: 84.7, 48.15, 33.5, 65.43, and 12.57 ppm, respectively. While the results obtained in loc2 were found as follows: 105, 65.1, 41.3, 55.4, and 12.74 ppm, respectively. The average elemental concentrations by XRF of these elements Cr, Ni, Cu, Zn, and Pb in loc1 were found as follows: 77.21, 43.72, 27.62, 86.96, and 18.74 ppm, respectively. While the results obtained in loc2 were found as follows: 123.33, 57.41, 35.99, 98.85, and 16.43 ppm, respectively.&#x0D; A statistical test (t-test) was applied to the data of both methods without any significant difference between the two techniques. The results obtained were compared to WHO permissible limits. Correlations between different elements were performed. Hierarchical cluster analysis was done for the data. The average elemental concentrations were calculated and compared with data from the literature.

Walrus teeth as biomonitors of trace elements in Arctic marine ecosystems

Effective biomonitoring requires an understanding of the factors driving concentrations of the substances or compounds of interest in the tissues of studied organisms. Biomonitoring of trace elements, and heavy metals in particular, has been the focus of much research; however, the complex roles many trace elements play in animal and plant tissues can make it difficult to disentangle environmental signals from physiology. This study examined the concentrations of 15 trace elements in the teeth of 122 Pacific walruses (Odobenus rosmarus divergens) to investigate the potential for walrus teeth as biomonitors of trace elements in Arctic ecosystems. Elemental concentrations were measured across cementum growth layer groups (GLGs), thereby reconstructing a lifetime history of element concentrations for each walrus. The locations of GLGs were used to divide trace element time series into individual years, allowing each GLG to be associated with an animal age and a calendar year. The elements studied exhibited a great deal of complexity, reflecting the numerous factors responsible for generating tooth trace element concentrations. Generalized linear mixed models were used to investigate the importance of age and sex in explaining observed variation in trace element concentrations. Some elements exhibited clear physiological signals (particularly zinc, strontium, barium, and lead), and all elements except arsenic varied by age and/or sex. Pearson's correlations revealed that elements were more strongly correlated among calendar years than among individual walruses, and correlations of trace elements within individual walruses were generally inconsistent or weak. Plots of average elemental concentrations through time from 1945 to 2014 further supported the correlation analyses, with many elements exhibiting similar patterns across the ~70-year period. Together, these results indicate the importance of physiology in modulating tooth trace element concentrations in walrus tooth cementum, but suggest that many trace elements reflect a record of environmental exposure and dietary intake/uptake.

СОДЕРЖАНИЕ И РАСПРЕДЕЛЕНИЕ МИКРОЭЛЕМЕНТОВ В ПОЧВОГРУНТАХ ПРИ ОСВОЕНИИ НЕФТЯНЫХ МЕСТОРОЖДЕНИЙ РЕСПУБЛИКИ КАЛМЫКИЯ

The article presents the results of chemical analysis soils of drilling sites of the Sostinsky and Mezhozerny oil fields of the Republic of Kalmykia. The content of sodium ions is more than 2 times higher in both deposits. At the same time, the content of chlorides in some areas of the Mezhozerny field reaches its maximum. As a result, the soils are highly saline in terms of the degree of salinity and are mainly chloride-sulfate-sodium in terms of the type of salinity. In oil fields, oil spills lead to the accumulation of organic carbon many times, with the total content of organic matter exceeding up to 5 times. The increase in the content of petroleum products is greatest in water discharge and wellheads. Studies on the content of heavy metals in the soils of oil fields showed that the average content of elements does not exceed the maximum permissible concentration of substances. At the same time, the content of most heavy metals exceeds the background ones, for example, lead, cadmium up to 2 times, strontium up to 8 times, mercury up to 6-12 times. In comparison with the clarke of the lithosphere (according to Vinogradov), an ecological-geochemical specialization in cadmium is noted. In the soils of the Sostinsky deposit, in the series of distribution of heavy metals, the maximum value is typical for cadmium, and in the Mezhozernoye deposit for mercury. At the Sostinskoye deposit, higher than the background is characteristic of such elements as: lead, vanadium, copper, strontium, and at the Mezhozernoye deposit, the excess of the background is achieved for such elements as: cadmium, zinc, lead, vanadium, copper, chromium, strontium.

Characteristics and evaluations of heavy metal contents in irrigation water sources on a suburb farmland in the lower reaches of Xijiang River in the early busy season of farming

Abstract The pollution of heavy metals in irrigation water was related to the management-control of the risk of heavy metals in farmland and the safe production of crops. There were various sources of irrigation water in the suburb farmlands of Xijiang River. We investigated the sources and distribution characteristics of heavy metals in the irrigation water sources on a riverside and inside-dyke farmland of Xijiang River. According to sample test results, it was found that nearly 100% of heavy metals that we were concerned about were detected in the irrigation water sources in the study. The box plot showed that the average content of other elements ranged from 1.65 to 43.75 μg·L−1, and the average level of cadmium was 0.02 μg·L−1 in the studied area. According to quantitative evaluation index and analysis of distribution characteristics, most heavy metals were at relatively low concentration in the irrigation water sources, while mercury content was far greater than other elements, followed by arsenic. Arsenic and mercury had become increasingly prominent problems in local irrigation water sources. River quality was more likely to be affected by river water and agricultural activities, while groundwater quality was more likely to be affected by natural causes. According to single/comprehensive water-quality evaluations, the comprehensive water quality evaluation ranged from level I to level III, but the single-factor index evaluations of mercury in most water samples and arsenic in two groundwater samples were of ‘Inferior’ level. Attention should be paid to the monitoring of mercury and arsenic (in the groundwater) in the studied area. The disposal methods of farmland water inflow and drainage should be increased if necessary, and reducing the influence of human activities on the natural weathering and leaching of heavy metals was an effective measure to avoid risk of agricultural production.

Establishment of regional background for heavy metals in the soils of the Lower Don and the Taganrog Bay coast

Data on the regional geochemical background and threshold values of heavy metals are required to establish anomalies and assess soil pollution. As a rule, the background values are the average contents of elements in natural undisturbed soils, or the threshold values for the study area, obtained by statistical methods. The aim of the study is to obtain geochemical threshold values of heavy metals in the soils of the Lower Don and the Taganrog Bay coast using different statistical approaches. A total of 86 topsoil samples were collected from the study area. The concentrations of Cr, Mn, Ni, Сu, Zn, As, Cd, and Pb were analyzed by X-ray fluorescence. The median element concentrations in the soils of the study area were consistent with world soil average and metal concentrations in background soils of protected area. Using a ‘geochemical’ approach is not suitable for this dataset because it does not take into account the natural variability of concentrations in different soil types. The Tukey inner fence method delivers estimates that do not detect outliers for Ni, As, Cd, and Pb. The ‘median + 2 median absolute deviations’ method was the most appropriate, as it consistently provided the most conservative background values.

Trace Elements in Mollusks, Crustaceans and Fish Commonly Consumed by the Catfish &amp;lt;i&amp;gt;Chrysichthys nigrodigitatus&amp;lt;/i&amp;gt; Lac&amp;#233;p&amp;#232;de, 1803 from the Lake Togo-Lagoon of An&amp;#233;ho Hydrosystem (Southern Togo)

The omnivorous fish species, C. nigrodigitatus feeds mainly on benthic organisms and may therefore consume contaminated food throughout its food web. This can lead to the bioaccumulation of contaminants such as trace elements in their tissues. However, fish consumption is a major pathway of human exposure to contaminants which may cause public health problems. The aim of the present study is to assess trace elements contamination in some species from the food web of C. nigrodigitatus. For this, 10 main food items of the silver catfish were collected at two sites from February to July 2017 and analyzed using an Atomic Absorption Spectrometer coupled with a hydride and cold vapour generator. The concentrations of trace elements varied greatly from one species to another and within each species. These values ranged from 0.007 mg/kg for Hg in C hippos to 354.84 mg/kg for Mn in P. fusca. The most contaminated species by trace elements were benthic organisms: M. perna (Cd, Pb, Hg), Pagurus sp. (Cr, Ni, Cu, Zn), G. paradoxa (As) and P. fusca (Mn). The average concentrations of trace elements found in species were, for the most part, above WHO standards except Hg in M. perna and G. paradoxa. The water-based bioconcentration factors (BCFw) reach 92.58 for Cd, 44.72 for Pb, 382.49 for Hg and 1514.34 for As in M. perna. It is therefore necessary to pay particular attention to this ecosystem and to put in place a better management plan.

Pollution Characteristics and Risk Assessment of Heavy Metal Elements in Sediment in the West Lake of Hengshui Lake

21 sampling points were set in the West Lake of Hengshui Lake including 20 fish ponds and 1 natural pond to analyze the contents distribution of heavy metal elements including Cr, Zn, Pb, Cu, Cd, Hg, As, and Sb in sediment. The degree of heavy metal pollution was evaluated by the geoaccumulation index (Igeo) method. The results showed that the concentrations of Cr, Zn, Pb, Cu, Cd, and Hg at in all sampling points of the fish ponds were lower than soil risk screening values of agricultural land in soil environmental quality: risk control standard for soil contamination of agricultural land (trial) (GB 15618‐2018). The concentrations of As at 5 sampling points were higher than soil risk screening values and lower than soil risk control values of agricultural land in GB 15618‐2018. The concentrations of Sb were lower than soil risk screening values of construction land in soil environmental quality: risk control standard for soil contamination of development land (trial) (GB 36600‐2018). The evaluation results of the geoaccumulation index method showed that the pollution degrees of Cd, Pb, and Hg were moderately contaminated in general, the pollution degree of Cu was uncontaminated to moderately contaminated in general, the pollution degrees of Cr and As were uncontaminated to moderately contaminated in some sampling points, and Zn and Sb could be regarded as uncontaminated in sediment of the fish ponds in the West Lake of Hengshui Lake. Otherwise, the average contents of other heavy metal elements in sediment of the fish ponds in the West Lake of Hengshui Lake were higher than the background value of soil in Hebei Province (BVSH) except for Zn and Sb. The average contents of seven heavy metal elements in sediment of the natural pond in the West Lake of Hengshui Lake were lower than BVSH except for Cr. The result can be regarded as no pollution in the natural pond because the values of Igeo were all lower than 0. The heavy metal pollution in the sediment of the West Lake of Hengshui Lake may be due to the introduction of feeding. The water environment of the West Lake of Hengshui Lake can be effectively improved by cleaning up the sediment of fish ponds and “returning fishing to wetland.”

РУХЛИВІСТЬ УРАНУ ТА ЕЛЕМЕНТІВ-СУПУТНИКІВ У КОРІ ВИВІТРЮВАННЯ УРАНОВОРУДНИХ АЛЬБІТИТІВ

The work considers the mobility series, the features of the hydrogenous mobilization of uranium and elements-satellites of the material complexes of the mineral-forming systems in the weathering crust of uranium-ore albitites of the Ukrainian Shield. Chemical elements that are companions of uranium can enter both concentrating minerals and ordinary rock-forming minerals containing these elements. The first include native metals – gold, bismuth, lead; sulfides: Cu, Zn, Pb, Ni, Co; monazite, zircon. Examples of the second group of the minerals are feldspars with rubidium, strontium, lead; egirin, ribecite, sphen with vanadium. Samples of rocks to calculate the average content of chemical elements and their mobility were formed taking into account the composition of the rocks and the degree of weathering. Titanium, the least mobile element, was used as a conditionally stable element, for which, in fact, all calculations were performed. Approbation of the method at all levels, including the root base, disintegration zone, hydromica-kaolin and kaolin weathering crust, soil layer (B- and A-horizons) and scattering fluxes, showed quite satisfactory results. Wastes from the industrial development of uranium deposits of albite formation, that are (and will be) stored, being essentially a crushed mineral concentrate enriched in uranium and heavy metals, which in conditions of hypergenic processes conducive to oxidation and decomposition, undoubtedly pose a potential threat of environmental pollution . A significant part of uranium and related elements in all blocks of rocks that are subject to operational excavation can be classified as “mobile”, ie has a fairly high migration capacity. This form can be a source of contamination of groundwater and surface water, and soils. Calculations show that uranium in all areas of the weathering crust behaves as a mobile element, prone to scattering. The share of uranium removed from different zones is 25-42% (0.11-0.19 g/t), which in absolute terms is the maximum in the kaolin zone. The main role in the migration of radionuclides is played by water erosion under the influence of precipitation. Therefore, to reduce hydrogen pollution, it is necessary to provide underlayment of dumps with clay and carbonate rocks. To limit the impact of wind erosion, it is necessary to fill the dumps with a layer of inert soil.

Content and distribution of some chemical elements in the poplar leaves (Populus laurifolia) in Ulaanbaatar

In the last more than two decades, technogenic environmental pollution of Ulaanbaatar (Mongolia) has become a critical issue due to the rapid growth of the city’s population and environmental objects such as soil, plant and water in Ulaanbaatar territory have been heavily contaminated through air. The objectives of this study were (1) to determine the toxic and biophilic elements in the leaves of laurel poplar (Populus laurifolia) in Ulaanbaatar (Mongolia) and to study the behaviour and interdependence of its distribution, (2) and to assess the ecological state of laurel poplar (Populus laurifolia). In the leaves of laurel poplar (Populus laurifolia) on the territory of Ulaanbaatar, the distribution of most of the studied toxic and biophilic elements is even, but only Mg, Ca, and Mn are not evenly distributed. The biogeochemical feature of laurel poplar (Populus laurifolia) on the territory of Ulaanbaatar was studied by comparing it with the value of the world clarke and with the average content of elements in plant ash according to Alekseenko and with the background value. Our study revealed the accumulation of Zn, Ni, Cd, Pb and the scattering of Fe, Mn, Co, Cu in the leaves of laurel poplar (Populus laurifolia) in Ulaanbaatar In Populus laurifolia leaves in Ulaanbaatar area the median value of Fe/Mn ratio is 4.2-2.7 times, and the median value of Pb/Mn ratio is 6.7 times higher the normal and Cu/Zn ratio is at an equilibrium. The highest Fe/Mn ratios are found along the main highway (10.45) and in the city centre (11.09).

Ecological and Geochemical Features of the Underground Waters of the Semipalatinsk Test Site

The results of the study of ecological and geochemical features and assessment of the water quality of water sources located on the territory of the Semipalatinsk test site are presented. The studied waters are diverse in chemical composition: 14 % of the samples had hydrocarbonate, 69 % – sulfate, and 17 % – chloride types of waters. On the basis of the revealed features of the elemental composition of the underground waters of the Semipalatinsk test site, decreasing series of excess of the average concentrations of elements in water in relation to the composition of waters of the zones of hypergenesis and continental salinization were constructed: U14&gt; Mo8&gt; Sr8&gt; V3(hypergenesis zone), U5&gt; Mo3&gt; Sr3&gt; V2(zone of continental salinization). For the groundwater of the Semipalatinsk test site, specific elements were identified, such as U, Mo, Sr and V. The water quality was assessed for the studied chemical components based on comparison with the standards of the Republic of Kazakhstan and the World Health Organization (SaNPiN No. 209, WHO 2011).

11000-Year Record of Trace Metals in Sediments off the Southern Shandong Peninsula in the South Yellow Sea

Geochemical background values are the normal concentration of trace metals in the natural environment and sediment cores have been proved to be excellent samples to get these values. The trace metal (Cu, Pb, Zn, Cr, Cd, As, Hg, Ni, Li, and Co) concentration profiles along a sediment core are investigated to get the background values and to assess the depositional processes and contamination levels off the southern Shandong Peninsula, China. All the metals, except As and Hg, had similar concentration profiles with the highest average values during the period of 6 − 3 kyr. The high concentrations of As and Hg occurred before 6ka and during the period of 3 − 0 kyr. The difference in metal concentrations before and after 6 kyr was mainly attributed to the source of core sediments, which are derived from proximal sediment on the Shandong Peninsula before 6 kyr and the mixture of proximal sediment and Yellow River sediment after 6 kyr. The effects of particle size and human activity were mainly contributed to the metal concentrations since 6 kyr. The average concentrations of trace elements in sediments between 6 and 3 kyr were selected as background values. The principal component factor analysis indicate that the metals were from the natural sources throughout the observed depositional period, with the exception of As and Hg, which may had anthropogenic sources for the sediments from the bottom 2 m of the core. Their geoaccumulation indices indicate that the sediments were not contaminated for Cu, Zn, Cr, Cd, Pb, Ni, Li and Co, whereas they were contaminated recently for As and Hg due to the regional civilization and human activities.

Identification of the spatial distributions, pollution levels, sources, and health risk of heavy metals in surface dusts from Korla, NW China

Abstract A total of 54 surface dust samples were gathered from Korla in NW China, and the concentrations of six heavy metal elements, such as Hg, Cd, As, Pb, Cr, and Cu, were determined by standard methods. The geostatistical analysis, multivariate statistical analysis, pollution load index (PLI), and the US EPA health risk assessment model were used to analyze the spatial distribution, pollution, and its potential health risk of heavy metals in surface dusts, and the main sources of heavy metals were also identified. The obtained results indicate that the average concentrations of As in surface dust of Korla is lower than the background values determined in Xinjiang soil, whereas the average concentrations of Hg, Cd, Pb, Cr, and Cu elements exceeded the corresponding background values by factors of 3.71, 1.87, 1.96, 1.14, and 1.29, respectively. The higher concentration of analyzed heavy metals is observed in the northeastern and northern parts in the study area. The pollution level of heavy metals decreased in the following order: Hg &gt; Pb &gt; Cd &gt; Cu &gt; Cr &gt; As. Based on the identified concentrations, the collected dust samples are found to be heavily polluted by Hg and slightly polluted by As, and the remaining elements, Pb, Cd, Cu, and Cr, are found to be low polluted. Furthermore, the PLI values of heavy metals in surface dust vary between 0.74 and 2.74, with an average value of 1.40, at the low pollution level. In addition, As in surface dust in the study area is mainly natural source, while Hg, Cd, Cr, Cu, and Pb are mainly anthropogenic sources. Overall, the carcinogenic and noncarcinogenic health risks of the analyzed elements, instigated mainly by oral ingestion of surface dust, are found to be within the acceptable range for both children and adults. As and Cr are the main noncarcinogenic elements, whereas Cr is the major carcinogenic element among the investigated dust-bound heavy metals in Korla.

A study of atmospheric pollutants (particulates, metallic elements) at an agricultural site

In this study, the total suspended particulate (TSP) concentrations and dry deposition of ambient air particulates are measured using a high-volume air sampler and a dry deposition plate at an agricultural sampling site in central Taiwan from March of 2019 to February of 2020. In addition, the concentrations of metallic elements attached to the particulates and dry deposits are analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). Finally, the TSP and metallic elements concentrations in TSP at different sampling sites around the world are also compared and discussed. The results indicated that the average highest TSP concentrations and dry depositions values both occurred in autumn, and the agricultural sampling site had the average greatest ambient air particulates dry depositions velocities when compared with other previous characteristic-related studies in Taiwan. In addition, metallic element Al had the average highest concentrations and dry depositions and metallic element Cd had the average lowest concentrations and dry depositions values in this study. In addition, metallic elements Cr, Cu, Pb, and Zn had the average highest concentrations when compared with other typical sampling site studies (airport, suburban, downtown, residential, industrial, and wetlands) in central Taiwan. Furthermore, when compared with the other previous metallic elements concentrations found in related studies in other regions from 1978 to 2020, the results obtained in this study indicated that the average metallic element concentrations Cr, Cu, Pb, and Zn in Taiwan were only lower than those reported in India and China. Taiping District is the main fruits production area in central Taiwan. Therefore, continued monitoring of ambient air related pollutants and finding the possible pollution sources have become an important issue for this agricultural site. From the above analysis, we also conclude that ambient air particulates and all the metallic elements dry deposition values obtained in this study were higher than those from the other characteristic sampling sites where studies were previously conducted in Taiwan.

Mass balance of metals during the phytoremediation process using Noccaea caerulescens: a pot study.

There are two widely used methods to estimate the time taken for phytoremediation for the removal of the target pollutants, i.e., using the data of metal uptake by the harvested parts of the selected plant or using the decrement in average element content between the beginning and end of the remediation. The latter not only depends on sampling points but is also determined by sampling time because even if the soil is initially perfectly homogenized, plant growth itself heterogenizes the soil as time goes by. In this study, phytoremediation was tested on one homogenized soil obtained from various soil samples taken within an e-waste dismantling and recycling site, and the remediation time for different points of bulk and rhizosphere soil was estimated using the two methods. Phytoremediation efficiency, as assessed by the change in soil metal concentrations over 100days, widely varied depending on which of the six soil compartments of the pot was sampled, and the standard deviations of Cd, Zn, Pb, and Cu increased as the experiment proceeded, indicating the inaccuracy of this method. When applied to rhizosphere soil, this method led to a large overestimation of phytoremediation efficiency for Cd and Zn, which was 81- and 77-fold that was obtained by measuring the actual amount of metals taken up by Noccaea caerulescens. The significant difference between the two methods indicated that the blended soil became heterogeneous during the phytoremediation process because the species extracted metals from different soil parts, manifested by the variation in the metal content. The gap between these two estimation methods decreased when the soil was mixed thoroughly at the end of the experiment. This work shows that calculating the metal decontamination efficiency based on the measurement of the actual amount of metal taken by the plant is more robust than estimating it based on the evolution of soil metal concentration over time. In addition, our study reveals that using N. caerulescens may not be appropriate in Pb- or Cu-polluted soil, since this species mobilized these metals but did not extract them.

СОДЕРЖАНИЕ ХИМИЧЕСКИХ ЭЛЕМЕНТОВ В ОРГАНАХ ТРЁХ ВИДОВ МОРСКИХ РЫБ

The concentrations of 24 elements were investigated in the organs and tissues of commercial fish species – pollock, cod and scomber from fishing zones of Far Eastern region. The levels of element concentration in fish are changed greatly in several orders of magnitude, reflecting it content in the environment from the one side, and it’s role in biochemical processes from the other side, providing vital functions and survival of fish. The liver accumulates maximal concentrations of most elements, the muscle tissues are distinguished by relatively low content of elements. The average concentrations of toxic elements As, Cd, Hg, Pb don’t exceed it’s maximal permissible levels of concentration.

Results of Studying Physicochemical Characteristics of Atmospheric Aerosol in the 71st Cruise of RV Akademik Mstislav Keldysh

In summer 2018 along the route of the 71st cruise of RV Akademik Mstislav Keldysh in the North Atlantic we carried out the measurements of such atmospheric aerosol characteristics as aerosol optical depth, near-surface aerosol and black carbon concentrations, content of chemical elements in aerosol samples, and organic and elemental carbon, as well as the isotopic composition of black carbon. It is shown that the average values of most characteristics decrease severalfold during passage from the Baltic Sea to the North Atlantic (57°–60° N), and then to the Norwegian Sea. For instance, the average black carbon concentration decreased from 83 to 29 ng/m3. Episodic impact of continental aerosol was noted even in remote regions of ocean. Outflow of smokes from forest fires in the north of Canada to the region of measurements (southward of Greenland) had the strongest effect on aerosol characteristics. The average concentrations of chemical elements in aerosol composition over the North Atlantic were several times larger than in the Arctic region, and smaller than in the background region of Siberia.

The Accumulation of Al, As, Li, Mg, Mn, S, Si, Ti, and V in the Mussel Mytilus galloprovincialis from the Moroccan Mediterranean Coastal Areas: Trends Pertaining to Seasons and Levels

The accumulation levels of elements (Al, As, Li, Mg, Mn, S, Si, Ti, and V) in the soft tissue of mussels (Mytilus galloprovincialis), collected monthly in 2016, from Junuary to December, from sampling sites of the mussel farming facilities installed in the coastal areas of Al Hoceima, were investigated. The studied element levels were determined by using Inductively Coupled Plasma — Optical Emission Spectrometry (ICP-OES 720-ES). Descending order of the average element concentrations in soft tissue of M. galloprovincialis was S > Mg > Si> Al > Mn > Ti > As >V > Li. Element contents (Al, As, Mg, S and V) in tissue of mussels were significantly different (P < 0.05) between seasons, being highest in winter and lowest in summer. Strong correlations were observed between studied elements and chlorophyll a, indicating the importance of food for metal bioaccumulation in mussels in this period of the season. The observed strong correlations for metal levels in tissues of mussels can be explained by their common sources, which are associated with anthropogenic effects. The detected seasonal variations of investigated element concentrations in soft tissues of M. galloprovincialis could be attributed to physicochemical parameters such as temperature, salinity, dissolved oxygen, nutrients and food availability, as well as the biological status of the mussel. This study may provide basic information for detecting the current pollution status of investigated elements in Al Hoceima coasts from the Moroccan Mediterranean Sea using M. galloprovincialis as biological indicators.