Variations In Heavy Metal Concentrations Research Articles

Heavy metals accumulation in aquatic macrophytes from an urban lake in Kashmir Himalaya, India

Pollution of aquatic systems by heavy metals strongly affects food chain relationships through the process of biomagnification. In this study, the concentration of various heavy metals like Iron (Fe), Copper (Cu), Manganese (Mn), Lead (Pb), Zinc (Zn), Cadmium (Cd), Chromium (Cr), and Cobalt (Co) was determined in water and their sequestration capability was evaluated using three aquatic macrophytes Potamogeton crispus, Phragmites australis, and Ceratophyllum demersum in Nigeen Lake, Kashmir Himalaya. The concentration of different heavy metals was determined using atomic absorption spectrophotometer (AAS). The concentration of heavy metals in water was in the order of Pb > Fe > Zn > Cd > Mn > Cu > Cr > Co. In water, the concentration of Cd, Co, Fe, Pb, and Mn was above the permissible limits for drinking water set by World Health Organization (WHO). The concentration of accumulated heavy metals in Potamogeton crispus was in the order of Fe > Zn > Mn > Pb > Cr > Cd = Cu > Co. Phragmites australis showed the accumulation pattern as Fe > Zn > Mn > Cd > Pb > Cu > Cr > Co and Ceratophyllum demersum accumulated heavy metals in the order as Fe > Zn > Pb > Mn > Co > Cr > Cd > Cu. The study suggests that all the three macrophytic species viz: Potamogeton crispus, Phragmites australis, and Ceratophyllum demersum have the high potential to accumulate heavy metals and can be effectively used to remediate contaminated soils, wastewaters, and aquatic ecosystems.

Heavy Metal, Rare Earth Element and Pb Isotope Dynamics in Mussels During a Depuration Experiment in the Gulf of Aqaba, Northern Red Sea

Mussels are considered highly efficient marine biomonitors, tracing anthropogenic and natural variations in heavy metals and various organic compounds. While heavy metals depuration processes in biomonitors are of growing interest, less knowledge is available regarding their Pb isotopes and rare earth elements (REEs) accumulation-release dynamics, and their response to short-term anthropogenic and terrigenous perturbations. Here, we report the results of a relocation experiment where a group of mussels (Brachidontes pharaonis) were extracted from a contaminated lagoon in the Gulf of Aqaba, northern Red Sea, and placed in water tanks that were flushed continuously with fresh, uncontaminated seawater. Specimens were removed periodically from the water table over a period of 13 weeks and trace and REEs and Pb isotopic compositions were determined separately for mussel’s shells and soft tissues. The results display a clear decrease over time in the concentrations of various heavy metals and REEs in the soft tissue, in concert with a similar shift in the Pb isotopic compositions toward seawater values. By contrast, the elemental and Pb isotopic composition of the shell presents little change over time. Coupling between the Pb isotopic composition of corresponding soft tissue and shell samples allows back-calculation of the timing and magnitude of abrupt pollution events and presents a novel approach for monitoring short-term pollution events. Nevertheless, given the coastal setting of the studied samples, it is important to consider the effects of terrigenous material on the results. Accordingly, Al-normalized element concentrations, Pb isotopes and calculated Ce anomalies, are used to identify two distinct terrigenous end members controlling the contaminated lagoon and the pristine site. The study demonstrates the potential of using mussels as robust biomonitors of natural and anthropogenic environmental perturbations through the combination between elemental concentrations and the isotopic composition of Pb.

The potential of using Cedrus atlantica as a biomonitor in the concentrations of Cr and Mn.

Air pollution is becoming increasingly dangerous which is quite a significant issue of today's world, especially air pollution from heavy metal, whose emission increases with industrial and traffic activities. This is of great importance in terms of environmental pollution and human health. Heavy metals do not deteriorate and disappear easily on earth. They are liable to bioaccumulate within cells in organisms. Most of them demonstrate harmful effects in addition as a result of advanced accumulation, and thus they emerge as toxic and carcinogenic. Therefore, it is of great importance to observe the changes in heavy metal concentrations in the air. One of the most effective techniques for monitoring the change of heavy metal concentrations in the atmosphere is the use of annual rings of trees as biomonitors. In this study, in the annual rings of the Cedrus atlantica Manettitree cut at the Kastamonu province at the end of 2019, the variation of the concentrations of some of the heavy metals most associated with traffic density was tried to be determined. Within the scope of the study, Cr and Mn concentration in the outer bark and the inner bark was compared with the direction and wood for the variation of heavy metal concentrations. Also, variance analysis and Duncan test were applied and evaluated. As a result of the study, while the highest values in many heavy metals are generally obtained in the outer bark, the transfer of metals in the wood is limited, and some heavy metal concentrations change significantly depending on the direction, especially in the wood. This change is related to the traffic density, so Cedrus atlantica Manettiannual rings are very suitable as biomonitors for air pollution control.

Indigenous multiresistant bacteria of Cupriavidus pauculus IrC4 isolated from Indonesia as a heavy metal bioremediation agent

Abstract. Irawati W, Winoto SE, Kusumawati L, Pinontoan R. 2021. Indigenous multiresistant bacteria of Cupriavidus pauculus IrC4 isolated from Indonesia as a heavy metal bioremediation agent. Biodiversitas 22: 3349-3355. Heavy metal pollution is a serious environmental problem because it endangers humans, animals, and plants. Bioremediation of heavy metals using bacteria is an effective method to remove heavy metals. Cupriavidus pauculus IrC4 is an indigenous multi-resistant bacteria isolated from Indonesia. This study aims to determine the growth of this strain in a medium containing cadmium, mercury, lead, copper, and its ability to accumulate heavy metal. Bacterial resistance was observed by cultivating bacteria on a Luria Bertani medium containing various concentrations of heavy metals. Heavy metal accumulation was measured using atomic absorption spectrophotometer. The study showed that this strain could grow in a solid medium containing 5 mM cadmium, 13 mM lead, and 4 mM mercury, also in 0.5 mM of the heavy metal mixture. A high concentration of heavy metals resulted in lag phase elongation and logarithmic growth phase inhibition. C. pauculus IrC4 could accumulate copper, lead, and cadmium and lead up to 371.42 mg, 254.4 mg, 5.8 mg heavy metals per gram of dry weight of cells, respectively. In conclusion, this strain is a promising bacterium for use as a heavy metal bioremediation agent.

Uptake and accumulation of heavy metals by water body and Azolla filiculoides in the Anzali wetland

The Anzali international wetland is a valuable habitat to a wide variety of aquatic flora and fauna. This wetland ecosystem is being threatened due to various pollutants particularly the heavy metals discharging from different point and non-point sources. Concentration of various heavy metals (Cr, Pb, Hg, Cu, Zn, Cd, Ag and Ti) was examined in the water body and Azolla filiculoides (an exotic fern in the Anzali wetland). The samples regarding water and A. filiculoides were randomly carried out in three parts of the wetland (eastern, central and western parts) in May 2015. After preparing and digesting the samples, the concentration of the heavy metals was measured using ICP OES method. The obtained results showed that the concentration of Zn in water and A. filiculoides samples was higher than other heavy meals in all parts of the wetland (p < 0.05). Overall, concentration of the heavy metals was significantly higher in the eastern part of the wetland than other two sampling locations (p < 0.05). Also with comparing the concentration of the heavy metals in water and A. filiculoides, it was found that all examined metals (except Cd and Ag) in A. filiculoides had significantly higher concentration than water sample, while Cd and Ag in water and A. filiculoides did not have a significant difference with each other. Based on the results, it can be concluded that A. filiculoides can effectively absorb Cr, Pb, Zn, Hg, Cu, Cd, Ag and Ti so that it might be used as a valuable species for the bioremediation and the removal of heavy metals from the wetland.

Seasonal Variations of Lead and Chromium Concentrations in the Water Samples From Yamuna River in Delhi, India

Background: According to Hindu mythology, Yamuna River plays an impotent role as a holy water resource in Delhi, India. The lead and chromium concentrations were determined from the water samples collected from five different locations around this river in Delhi area. The contaminated water from this river is mostly used for drinking, agriculture, aquaculture, and storage as a holy water. Methods: The seasonal variations of heavy metal concentrations in the water samples collected from Yamuna river were determined for the summer, monsoon and winter supplies, using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Atomic Absorption Spectroscopy (AAS). Results: In the summer water samples, we found greater concentrations of both heavy metals than those for the monsoon season. The concentrations of lead and chromium in the water samples were higher than the permissible limits recommended by the World Health Organization (WHO). The water quality was not safe for drinking, cleaning and agriculture, nor for the aquatic animals, such as fish, amphibians and others. Conclusion: The condition of the water in Yamuna river is of great health concerns. Therefore, it is vital to take necessary actions to decontaminate the water from this river, and to draw effective strategies to minimize or prevent the current and future contaminations added to this important water resource in India.

Assessment of Human Health Risks Associated with Heavy Metals Accumulation in the Freshwater Fish Pangasianodon hypophthalmus in Bangladesh

In this study, pangas and feed samples were analyzed to estimate the levels of metallic elements and to profile the human health risks due to consumption of contaminated fish. This investigation confirmed significant variations in heavy metal concentrations among different tissues of pangas in the order of Ni > Cu > Pb > Cd > Cr in pre-monsoon and Ni > Cd = Cu > Pb = Cr in post-monsoon. Considerably higher concentrations of Pb, Cu, and Cr were estimated in liver; and Cd and Ni were detected in muscle than in other organs (p > 0.05). Statistically significant higher amounts of Cd, Ni, and Cu were observed in pre-monsoon than in post-monsoon. Furthermore, three metal pairs showed significant association (Pb–Ni and Pb–Cu involved positively; Cd–Ni acted negatively). In pre-monsoon, Cd, Pb, Ni, and Cu concentrations of feed significantly differed than those of pangas contents, whereas only Cu varied during the post-monsoon. Regression analysis revealed the significant effect of Ni content in feed on the Cu deposition of pangas (p-value 0.027, that was < 0.05). For the assessment of potential human health risk of the studied metals, estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and carcinogenic risk (CR) indices were calculated. Studied EDI indicated that an average adult ingested a higher amount of Ni and Cu than the recommended intake limit. Nevertheless, only the higher EDI of Ni increases the value of THQ and HI than standard limit indicates adverse non-carcinogenic risk. However, lower CR of Pb confirmed no serious health hazard due to the ingestion of pangas. Factor analysis through principal component and cluster analysis suggested that higher concentrations of Pb and Ni may be regulated by the feed used, geochemical properties, or rapid industrialization in the study area. A proper monitoring for controlling the quality of fish feed with sustainable planning for industrialization could secure the booming of pangasius aquaculture in Bangladesh.

A modelling study of a buffer zone in abating heavy metal contamination from a gold mine of Hainan Province in nearby agricultural area

The establishment of new buffer zone in the mine areas lacks the basis of theoretical model. As a case study, this study presents the partition model of new buffer zone in a small-scale mine area located in the remote mountainous region of Hainan province, China. The investigation carried out by integration of geostatistical interpolation maps using unmanned aerial vehicle has revealed that As, Cd, Pb, Zn, and Hg are mainly distributed near the tailing ponds and the dressing plant, while Cr and Cu are prominent near the agricultural area. The partition model of buffer zone was established in accordance to the transport velocity of the liquid phase heavy metal in soil. The boundary line of buffer zone is integrated by comparing the ‘predicted’ heavy metal concentrations with the ‘measured’ heavy metal concentrations. Principal component analysis (PCA) and the variations of heavy metal concentrations with elevation, slope, and distance were performed to further evaluate the reliability of the predicted buffer zone, indicating that the new buffer zone has a significant effect on minimizing transport of heavy metals from the mining area into the agricultural land. This study is suggestive to provide risk control and sustainable development strategy for the ecosystem protection in mine areas.

Growth Responses and Accumulation Characteristics of Three Ornamental Plants to Sn Contamination in Soil

Decorative ornamental plants have been applied as hyperaccumulators/phytoremediators to a wide spectrum of heavy metal contaminants. In this study, pot culture experiments were conducted to investigate the Sn tolerance and accumulation in Impatiens balsamina L., Mirabilis jalapa L. and Tagetes erecta L., in order to assess the possibility of these three ornamental plants to be used as phytoremediators of Sn-contaminated soil. Results show that all three plants exhibited strong tolerance to Sn contamination, and no significant visual toxicity was observed for all three plants grown under most of the Sn treatments. The amount of Sn accumulated in the three plants was positively correlated with the Sn concentration in the soil. The order of the Sn accumulative capacity was Impatiens balsamina &gt; Mirabilis jalapa &gt; Tagetes erecta. Impatiens balsamina and Tagetes erecta showed a low translocation ability (TF) (&lt;1), and the roots accumulated the highest Sn concentration, but Impatiens balsamina showed a relatively high bioconcentration factor (BCF, Sn concentration in each part &gt; 100 mg/kg after Sn treatment of 500 mg/kg). Meanwhile, the TF of Mirabilis jalapa was &gt;1, and the fluorescence accumulated the most Sn. In combination with the adaptation to high concentrations of various heavy metals, these three ornamental plants are potential candidates for Sn mining tailings or contaminated soil.

Water Pollution and Its Causes in the Tuojiang River Basin, China: An Artificial Neural Network Analysis

This work aimed to assess the water quality of the Tuojiang River Basin in recent years to provide a better understanding of its current pollution situation, and the potential pollution risks and causes. Water quality parameters such as dissolved oxygen (DO), ammonia–nitrogen (NH3-N), total phosphorus (TP), the permanganate index (CODMn), five-day biochemical oxygen demand (BOD5), pH, and concentrations of various heavy metals were measured in the Tuojiang River, according to the national standards of the People’s Republic of China. Samples were collected between 2012 to 2018 at 11 national monitoring sites in the Tuojiang River Basin. The overall water pollution situation was evaluated with back propagation artificial neural network (BP-ANN) analysis. The pollution causes were analyzed considering both industrial wastewater discharge in the upper reaches and the current pollution situation. We found potential risks of excessive NH3-N, TP, Cd, Hg, and Pb concentrations in the Tuojiang River Basin. Moreover, corresponding water pollution control suggestions were given.

Use of benthic foraminifera as a proxy for monitoring heavy metal pollution in the Swarnamukhi estuary, southeast coast of India

Benthic foraminiferal assemblages were surveyed as potential indicators of heavy metal pollution of sediments from Swarnamukhi estuary, southeast India. Grain size analysis indicated that the sediments were deposited under low energy conditions. Results of assessment by factor analysis and hierarchical cluster analysis showed relations among the heavy metals. The sediment pollution assessment was carried out using the Enrichment Factor (EF), and Pollution Load Index (PLI). The results showed significant seasonal variation in heavy metal concentrations, and several metals (e.g. Fe, Cr, Zn, Pb and Cd) had high abundance in the sediments. A total of 53 benthic foraminiferal species belonging to 20 genera and 3 suborders were recorded in the sediments. The effect of heavy metal pollution on foraminifera's species diversity was assessed. The assemblage changes and test abnormalities in foraminiferal species appeared to be proxies for evaluating environmental stresses. • Distribution and mobility of heavy metals in sediments collected from Swarnamukhi estuary were assessed. • A total of 53 species, 20 genera and 3 suborders according to their distribution was summarized. • Benthic foraminifera was used as a bio-indicator to evaluate the heavy metal pollution from the study area. • Benthic foraminiferal species and shell abnormalities were identified.

Influence of Heavy Metals on the Process of Anaerobic Fermentation of Biomass by the Consortia of Anaerobic Microorganisms

Heavy metals released into the environment have a negative impact on the development of living organisms and soil fertility. The use of biomass obtained on such soils as a substrate for biogas production is problematic since heavy metals affect the consortia of microorganisms-decomposers and methane producers, and, consequently, the biogas yield. Therefore, the effect of certain metal ions and their concentrations in the environment on the development of the anaerobicconsortia for biogas production is the topical question. We are aimed to generalize research findings across the influence of heavy metal compounds on the process of anaerobic fermentation of biomass and determination of limiting concentrations for the functioning of the anaerobic consortia. Analysis of the literature has shown that the addition of heavy metal salts to the working medium affects the process of anaerobic fermentation, which depends on the form of the introduced metal, its concentration, the preliminary adaptation of the consortia to the metal. The biogas yield depends on the concentration of the element under study and the presence of other elements in the substrate. It has been established that the allow­able concentrations of metal ions are as follows: for іron – 20 g/l Fe0 or 500 mg/l K2FeO4; for chromium – 50 mg/l Cr3+; for copper – 40 mg/l CuCl2; for zinc – 40 mg/l ZnCl2. The data obtained on the influence of various concentrations of heavy metals on the anaerobic fermentation process will make it possible to model and conduct further studies of the effects of both individual heavy metal ions and their combinations on the biotechnology of processing waste containing such metals.

Shungite application for treatment of drinking water – is it the right choice?

Abstract Shungite is a natural carbon containing material that is widely used in water treatment. Scientific research shows that shungite has good adsorption properties towards various organic compounds and heavy metals, as well as exhibiting antibacterial properties. Unfortunately, at the same time shungite releases various chemical elements into the water, including heavy metals. In this study changes in concentration of various heavy metals during drinking water treatment with one commercial and one non-commercial shungite sample were determined. Also sorption of Cu(II) with initial concentration of 2,500 μg/L onto shungite was investigated. The results showed that various heavy metals like nickel, copper, lead, cadmium, zinc, chromium and arsenic are leaching from shungite into water. Lead and cadmium exceeded the maximum acceptable concentration in drinking water for a few days, but nickel exceeded for up to 2 weeks. At the same time shungite showed good adsorption properties towards copper. Nevertheless, before using shungite in drinking water treatment, it would be advisable to assess the necessity and/or wash shungite with larger volumes of water for a longer period of time than is written in the instructions.

Application of Aztec Marigold (Tagetes erecta L.) for phytoremediation of heavy metal polluted lateritic soil

Heavy metals are pollutants of great concern due to their toxicity and immutable nature. As a result of human actions such as mining, industrial activity and agricultural practices, heavy metals find their way in to the soil. Phytoremediation is a a cost-effective, non-intrusive, and aesthetically pleasing technology in which herbaceous plants and trees are used to remediate and remove pollutants from soils. In the present study, potential of Tagetes erecta L. was assessed for phytoremediation of cadmium (Cd), lead (Pb) and zinc (Zn) contaminated lateritic soil. Pot experiments were conducted for various concentrations of heavy metals (ranging from 20 mg/kg to 160 mg/kg). The plant uptake of the heavy metals was analyzed after a 12-week growing period and was determined by analyzing residual heavy metal concentrations in aerial and subterranean parts of the plant by atomic absorption spectrophotometry (AAS). The total uptake of heavy metals by the plant increased with increasing heavy metal concentration in the soil. Considering the plant as a whole, the ability to uptake Zn and Cd was comparable and was significantly higher, approximately 13 times on average than its ability to uptake Pb. At lower concentrations, the ability was slightly higher for Cd, but at higher concentrations, Zn uptake was slightly higher. The order of accumulation of heavy metals in Tagetes erecta L. shoots was in the order of Cd > Zn > Pb, and the same order for roots was Zn > Cd > Pb. The bioconcentration factor (BCF) was greater than 1 for Cd (soil concentration Highlights •Aztec marigold (Tagetes erecta L.) was used for phytoremediation of heavy metal polluted lateritic soil

Alterations in photosynthetic pigments, antioxidant machinery, essential oil constituents and growth of menthol mint (Mentha arvensis L.) upon nickel exposure

The present study was conducted in view of the alarming increase in the concentration of various heavy metals like nickel, copper, lead, cadmium, and arsenic etc., in the soils globally. Little attention has been paid towards the deleterious effect of these heavy metals particularly nickel (Ni) on the performance of pharmaceutically exigent essential oil-bearing crops like menthol mint (Mentha arvensis L.). Menthol mint, a dominant essential oil-producing aromatic plant, is widely cultivated in Uttar Pradesh (India) and has wide applications in pharmaceutical industry. Nickel, an essential micronutrient and a main component of the plant enzyme urease, has vital role in plants and is required in very low amounts for normal growth and functioning of plants. In this study, Ni was applied in the form of NiCl2 with various concentrations of 20, 40, 60, 80, and 100 mg kg−1 Ni of soil and one set was kept as control. Interestingly, Ni at 20 mg kg−1 of soil significantly enhanced all the parameters studied, including constituents of essential oil, particularly menthone and menthyl acetate content. However, a significant reduction was observed in most of the parameters studied with increasing concentrations of Ni. The growth (plant height, fresh and dry weights and herbage yield), biochemical (photosynthetic pigments, chlorophyll fluorescence and carbonic anhydrase activity), and quality parameters (content of essential oil & its active constituents) exhibited a significant reduction over 20 mg kg−1 of soil. However, the activities of enzymatic antioxidants, such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX), and the level of proline (PRO) were enhanced at the higher concentrations of Ni. Thus, the present study confirms that Ni applied at 20 mg kg−1 of soil proved beneficial dose, whereas 100 mg kg−1 of soil produced toxic response for the overall growth and development of the mint crop.

Seasonal variations of heavy metals concentrations and pollution assessment of major dumpsites in Ilisan-Remo, Nigeria

Seasonal variations of heavy metals concentrations and pollution assessment of major dumpsites in Ilisan-Remo, Nigeria

Antarctic Adélie penguin feathers as bio-indicators of geographic and temporal variations in heavy metal concentrations in their habitats

Seabird feathers are effective indicators of heavy metal contamination. To propose a biological detection method suitable for the long-term monitoring of heavy metals in the Antarctic environment, eight heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in Adélie penguin feathers from different body parts, years, and molting grounds in the Antarctic were investigated in this study. It is found that the concentrations of heavy metals in the feathers showed differences among the body part of origin. The levels of the eight elements in the abdomen and back feathers were approximately the same, but some elements of them were significantly higher than those in the tail feathers. The Hg and Cd concentrations in the abdomen and back feathers increased from root to tip, regardless of the sampling year or molting ground. Based on a structural analysis of the feathers, Hg and Cd were mainly distributed in the feather vane rather than the shaft. The methylmercury content accounted for 83%–97% of the total mercury content in all feather samples, regardless of location, year, or body part, thereby supporting the assumption that mercury entering the feather was predominantly methylated and indicating that a relatively toxic form of Hg is excreted through the feathers. The heavy metals in feathers from the same molting ground showed significant differences over the sampling years. The average concentrations of As, Cr, Cu, Ni, and Zn increased significantly from 2015 to 2019, whereas those of Cd, Hg, and Pb tended to decrease. The concentrations of the eight elements in Adélie feathers from three molting grounds varied greatly, possibly in relation to their living areas and dietary structures. Feathers from the Ross Sea site had the highest Cd, Cu, Hg, Ni, and Zn concentrations, the highest As and Cr concentrations were detected in feathers from the Zhongshan site, and feathers from the Great Wall site showed higher Pb concentrations than those from the other two sites. This study established a long-term, nondestructive, and efficient method for monitoring heavy metal contamination in the polar environment in the future.

Investigation on four heavy metal constituents of commercial restorative Chinese medicines

This study undertook the analysis of Cd, Cr, Mn, and Pb constituents in the various forms of five restorative preparations from ten GMP Chinese medicine laboratories. Collected samples of the commercial drugs were digested with HNO3-HClO4 in the presence of microwaving, followed by atomic absorption spectrophotometric analysis the results showed higher levels in the Mn content (27.9 ± 19.8 ppm) than Cr (2.86 ± 2.04 ppm), Pb (0.247 ± 0.578 ppm), and Cd (0.157 ± 0.167 ppm), based on the dry weight of the samples. The variation of heavy metal contents between laboratories, prescriptions, prescribed doses, and lot numbers may be attributed to the differences in the origin of raw materials as well as the additives used in the processing procedure. Comparison between prescriptions exhibited higher heavy metal contents (53.6 ± 24.7 ppm, the sum of Cd, Cr, Mn and Pb) in Kim-So-Ku-Gien-Wan. For purposes of safety and quality in Chinese drugs,it is necessary to confine individual heavy metal content on the basis of potential toxicity.

Hydrodynamic Controls of Particulate Metals Partitioning Along the Lower Selenga River—Main Tributary of The Lake Baikal

In this study, the downstream effects of pollutants spreading due to hydromorphological gradients and associated changes in sediment transport conditions along the braided-meandering and deltaic distributary reach of a large river downstream section are discussed. We demonstrate the significance of hydrodynamic control for sediment-associated metal partitioning along the river. Typically, the downward decline of the sediment and metals spreading towards Lake Baikal is observed due to buffer effects in the delta. During peak flow, the longitudinal gradients in heavy metal concentration along the distributary delta reach are neglected due to higher concentrations delivered from the upper parts of the river. In particular, significant variations of heavy metal concentrations associated with the river depth are related to sediment concentration and flow velocity profiles. Various particulate metal behavior in silt-sand delta channels and the sand–gravel Selenga main stem emphasize the importance of near-bottom exchange for particles spreading with the river flow. Using empirically derived Rouse numbers, we found quantitative relationships between the ratio of particulate metals sorting throughout depth in a single river channel and the hydrodynamic conditions of sediment transport.

Effects of Some Heavy Metals (Cd, Cu, Pb, and Zn) Concentration on Qualitative Traits of Dill (Anethum graveolens L.) and Basil (Ocimum basilicum L.)

Soil pollution is a global concern from past to recent. Toxic and high resistance nature of chemical pollutants, such as heavy metals show their important as environmental risk and a serious problem for human health, because they can introduce to the food chain from contaminated environments. Experiments were conducted to evaluate the effect of Cd, Cu, Pb, and Zn on qualitative parameters of dill (Anethum graveolens L.), and basil (Ocimum basilicum L.) grown in polluted soil environment. Heavy metals concentration, total phenol and flavonoid, essential oil percentage, DPPH radical scavenging activity, super and nitric oxide radical scavenging activity in leave and stem parts of the plants were analysed in this study according to standard methods. According to results, Cu was the dominant heavy metal in leave and stem of both studied plants, followed by Pb, Zn, and Cd. The concentration of various heavy metals in dill was more than two times higher than basil. Total phenol and flavonoids showed significant differences in leave and stem in both plants. DPPH, super oxide and nitric oxide radical scavenging activity showed significant higher values in leave than stem in both plants.