High Concentrations Of Lead Research Articles

Phase transformation mechanism of oxidation roasting of low-grade polymetallic chalcopyrite ore in the presence of CaO

Low-grade polymetallic chalcopyrite ore has a high lead and iron content and a low softening point, which is difficult to treat using conventional pyrometallurgical and hydrometallurgical processes. In order to investigate the suitable methodology for efficient utilization, it was pelletized with CaO for oxidation roasting in the present work. By controlling the Po2 and Pso2 in the gas phase, the metal sulfide in the ore was converted into easily soluble metal oxide, the thermal analysis of the roasting process was carried out and the acid leaching of the extracted calcine at atmospheric pressure was investigated. The results show that by pelletizing with CaO and then roasting at 800 ? for 1 h, chalcopyrite is converted into CuO, which can be easily dissolved, galena and pyrite are converted into PbO2 and Fe2O3, respectively, and sulfur reacts with CaO and turns into CaSO4, which can fix the sulfur in the calcine. The copper leaching rate of calcine can reach 98.60 wt.% under atmospheric pressure in the H2SO4-H2O system. CaO can increase the softening point of raw materials, improve the roasting effect, promote the phase transformation of chalcopyrite in the oxidation process, and convert sulfur into CaSO4 to fix sulfur, effectively avoiding SO2 pollution to the environment.

Lead and cadmium content in wheat grain from different regions of Poland and risk analysis

The level of wheat grain contamination with lead and cadmium was determined using electrothermal atomic absorption spectrometry with Zeeman background correction (ETAAS) after microwave digestion. The obtained limits of quantification were 0.001 mg∙kg–1, for both metals. A total of 300 samples of wheat grain from agricultural regions of Poland were examined, 150 each from the two consecutive harvest years 2017 and 2018. None of the tested samples exceeded the maximum level of these metals, as specified in the European regulations. The contents of lead and cadmium in wheat grain from both years of harvest ranged from <0.001 to 0.098 mg∙kg –1 and from 0.006 to 0.098 mg∙kg –1, respectively. Despite similar ranges of these metals, the highest lead contents were two times lower than the maximum limit value, while the highest cadmium contents were close to it. As for lead, a significantly higher (p < 0.05) mean content of this metal was found in wheat grain from the 2018 harvest compared to 2017 and in the western compared to eastern regions of the country. However, the cadmium contents did not differ significantly between the two harvest years, but were significantly higher (p < 0.05) in wheat grain from the southern regions compared to northern regions of Poland. Additionally, the highest contents of cadmium, close to the maximum limit, were found in the South-West region and in the both years of harvest. The risk analysis of the occurrence of the excessive contents of toxic metals in wheat grain showed a low risk level for lead in all investigated regions, and a medium level for cadmium, in general.

Health risk assessment of heavy metals (lead and cadmium) in transgenic corn in Tehran

Corn plant and the products made from corn is one of the major transgenic concerning in the world, and due to public concerns about the presence of heavy metals in this product; the present study investigated the food safety in transgenic corn samples due to the presence of lead and cadmium. Iran has the highest exchange of agricultural products. Five packaged popular brands of raw corn samples and one unpackaged one as the bulk sample were purchased from Tehran markets in 2021, and after confirming transgenicity by quantitative real-time PCR and then wet digestion method. The heavy metal contents in all studied samples were analyzed by inductively coupled plasma spectrometer. Bulk samples had the highest content of lead and cadmium compared to other packaged studied samples. The comparison of lead and cadmium compared to the maximum permissible levels set by the National and international standards revealed that the these toxic heavy metals ‘contents in 100% of studied raw corn samples were higher than the maximum limit. The results of current study indicate that the Lead and Cadmium contents in the studied samples were 18 and 2.7 times higher than the maximum permissible limit (MPL).

Estimation of Soil Contamination with Heavy Metals in the Streets of Al-Diwaniyah City in Al-Qadisiyah Governorate, Iraq

This study aims to calculate the contamination levels of the elements (Pb, Cr, Ni and Cd) in soil samples taken from the Iraqi city of Al-Diwaniyah in the Al-Qadisiyah Governorate. Twenty samples of dust collected between the street and the sidewalk were collected for some areas of Al-Diwaniyah city, and then analyses were conducted to determine the concentrations of toxic and carcinogenic elements with the global determinants. The study’s findings revealed that there were very high concentrations of heavy metals compared to the internationally permissible limits, where the highest concentration of lead and chromium was in Main Street - Al-Asry District (112.6 ppm) and (115.1 ppm), respectively, and the lowest concentration of them was in Health Center Street - Al-Furat District (15.8 ppm) and (48.8 ppm), respectively, where the lowest lead value exceeded the internationally permitted limits and the lowest chromium value fell below the permissible limit. As for nickel and cadmium, the highest values of nickel and cadmium appeared in Main Street - Eastern Republican District which amounted to (135.2 ppm) and (2ppm), respectively, which is significantly greater than the internationally permissible limit, while the lowest values appeared in University Street - University District, which is (3.6 ppm) (0.05 ppm) respectively, which is less than the internationally permissible limit. It is noted from the results obtained that high rates of heavy metals concentrations in the soil samples of Al-Diwaniyah City indicate that the main factor in this rise is pollution caused by human activities, and the reason for this is due to the effect of vehicle launchers and some launchers of workshops and factories, as well as its presence in sand-laden dust of various sources. This rise might have an effect on the environment and human health at all of the selected sites.

Population status and ecology of the globally threatened moss Ditrichum plumbicola Crundw. on the Isle of Man

ABSTRACT Introduction. Ditrichum plumbicola Crundw. is a rare metallophyte that is threatened with global extinction. In this study, its population status and ecology on the Isle of Man were investigated. Methods. Surveys were carried out at all sites where the species may currently occur. Geographical coordinates of colonies were recorded using a GPS unit and counts made of occupied 1 m grid cells. Habitat and community composition were recorded by relevés. The chemical composition of occupied soil was also ascertained. Key results and conclusions. Two subpopulations of the species have occurred, associated with the two main ore bodies on the island. One of the subpopulations has become extinct. The other subpopulation comprises colonies at four nearby disused metal mines. It occurs at each in small quantity, with a total population of 47 occupied 1 m grid cells. The species is confined to open metalliferous spoil with high concentrations of lead. Solenostoma gracillimum is the only frequent associate. Management intervention to re-expose open metalliferous spoil will be required ultimately to save the species from extinction.

A survey of toxic elements in ready to eat baby foods in the US market 2021

ABSTRACT A non-targeted convenience survey was conducted in 2021 to estimate the range of total arsenic (As), cadmium (Cd), total mercury (Hg) and lead (Pb) concentrations in ready-to-eat baby foods. Four hundred samples were purchased both online and in brick-and-mortar retail. Samples included both organic and non-organic products, packaged in glass or plastic jars and foil or plastic pouches. Samples were analysed by acid assisted microwave digestion and ICP-MS with an emphasis on ultra-low detection limits. Limits of quantification were 2.26, 1.31, 0.72, and 3.14 µg/kg (ppb) for As, Cd, Hg and Pb, respectively. The median concentrations of As, Cd, Hg, and Pb in tested products were 2.60, 1.81, 0.09, and 1.38 µg/kg, respectively. Foods containing rice were more likely to contain arsenic. Foods with leafy greens, such as spinach and kale, were more likely to contain cadmium and foods with root vegetables had the highest concentrations of lead.

Microbial remediation mechanisms and applications for lead-contaminated environments.

High concentrations of lead (Pb) in agricultural soil and wastewater represent a severe threat to the ecosystem and health of living organisms. Among available removal techniques, microbial remediation has attracted much attention due to its lower cost, higher efficiency, and less impact on the environment; hence, it is an effective alternative to conventional physical or chemical Pb-remediation technologies. In the present review, recent advances on the Pb-remediation mechanisms of bacteria, fungi and microalgae have been reported, as well as their detoxification pathways. Based on the previous researches, microorganisms have various remediation mechanisms to cope with Pb pollution, which are basically categorized into biosorption, bioprecipitation, biomineralization, and bioaccumulations. This paper summarizes microbial Pb-remediation mechanisms, factors affecting Pb removal, and examples of each case are described in detail. We emphatically discuss the mechanisms of microbial immobilization of Pb, which can resist toxicity by synthesizing nanoparticles to convert dissolved Pb(II) into less toxic forms. The tolerance mechanisms of microbes to Pb are discussed at the molecular level as well. Finally, we conclude the research challenges and development prospects regarding the microbial remediation of Pb-polluted environment. The current review provides insight of interaction between lead and microbes and their potential applications for Pb removal.

Spectroscopic study of the coloring techniques used in Egyptian ceramics from the ptolemaic and roman period

The manufacture of the Egyptian Faience through the periods of Ptolemaic and roman shows intense use of polychrome; our main concerns in this research are investigating the parameters controlling the blue color variation and the production of the apple green Faience. Archaeological faience samples belonging to the Ptolemaic and Roman periods representing various color hues were extensively studied using multiple spectroscopic techniques to explore the color palette of the Egyptian artist in this period and highlight the most significant features of their ways of coloring and fabrications. X-ray Fluorescence (XRF) and Scanning Electron Microscopy (SEM) results revealed quartz-rich body feature for all samples, with defined boundaries in some samples due to coloring techniques. The investigated Faience are not lead-alkaline glazes but possibly soda (plant ash) or mixed-alkali glazes with inter-particle glass phases. The high lead content accompanied by antimonite and percentage of sulphur suggested the usage of natron salt flux. The apple green glazes are a yellow lead antimonite mixed with copper oxides. The color varies from deep apple green to light apple green based on the content of oxides in the sample.

Regulation of three subtypes of SOD gene in Aleuroglyphus ovatus (Acari: Acaridae) under lead stress

Superoxide dismutase (SOD) is an important enzyme that acts as the first line of protection in the mite antioxidant defense system and involves in eliminating reactive oxygen species (ROS) under harsh environmental conditions. Lead pollution is becoming increasingly serious and poses a serious hazard to the health and survival and reproduction of organisms. Nevertheless, the SOD gene family was yet to be reported in stored grain pest mite (Aleuroglyphus ovatus). In the present study, A. ovatus was reared on artificial diets treated with different concentrations of lead (12.5, 25, 50 and 100 mg/kg); the treatment fed on artificial diet without lead was marked as the control group (CK). Then three different subtypes of SOD were cloned, including AoSOD1 (Cu-ZnSOD), AoSOD2 and AoSOD3 (MnSOD). Enzyme activity of the egg stage was the lowest, and that of the protonymph stage was the highest. The enzyme activity of A. ovatus increased initially before dropping with increasing lead concentration, nevertheless, it was still substantially higher than that in CK. The analysis of SOD enzyme activity specified that it was higher at 25 mg/kg lead in each mite stage compared to other concentration groups. All three genes were up-regulated and thereafter reduced in the embryonic stage, according to an examination of mRNA expression levels; tritonymphs, in particular, attained the highest level. The expression level of the SOD genes also changed with lead concentration. It increased after an initial decline trend with increasing lead concentration, and then peaked in the 100 mg/kg lead group, which were 3.1 times (AoSOD1), 4.1 times (AoSOD2), and 2.3 times (AoSOD3) the control group, respectively. In this study, three AoSOD genes had developmental stage-specific mRNA expressions, and the expression of SOD enzyme activity was encouraged by the higher lead concentration, and the mRNA expression level of the AoSODs genes was not synchronized with the enzyme activity.

Achieving highly efficient and stable MAPbI3 planar solar cell by embedding Cs+, Fe2+, and Cd2+ metal inorganic cations in perovskite structure

Perovskite solar cells (PSCs) have been attracted the attention of many researchers due to their high conversion efficiency, low manufacturing cost, easy manufacturing steps, high light absorption, and the possibility of changing the photo electronic properties by modifying the chemical structure. Despite the mentioned advantages, the low stability of PSCs and toxicity of lead in the perovskite layer were the challenging issues in this field. In this regard, the use of mixed cation and mixed halide perovskite compounds with high crystal quality, efficiency, and stability has attracted enormous attention. In this project, Fe2+, Cd2+, and Cs+ cations with various contents (Fe2+ + Cd2+: 5% and 10%; Cs+: 5% and 10%) were partially replaced the Pb2+ and CH3NH3+ cations, respectively in the MAPbI3 perovskite structure through a two-step process using spin-coating. The as-synthesized [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 5, 10%, y: 5, 10%) perovskites were characterized with X-ray diffraction (XRD), grazing incidence X-ray diffraction (GIXRD), and field emission scanning electron microscopy (FESEM). The optical properties of prepared compounds were investigated by ultraviolet–visible (UV–Vis) and photoluminescence (PL) spectroscopy. The photovoltaic behavior as well as stability of solar cells containing MAPbI3, [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 5%, y: 5%), and [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 10%, y: 10%) perovskites as active layers were evaluated by current density-voltage (I–V) under AM1.5G illumination.Results showed that partial substitution of CH3NH3+ cations with Cs+ and Pb2+ cations with Fe2+ + Cd2+ in the CH3NH3PbI3 structure improved crystallinity and photovoltaic parameters. The average power conversion efficiency (PCE) of six solar cell containing [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 10%, y: 10%) perovskite layer was 21.04% which was 1.03 and 1.21 times higher than that cells containing [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 5%, y: 5%) and MAPbI3, respectively.The electrochemical impedance spectroscopy (EIS) was utilized to study the charge transfer resistance (Rct) and recombination resistance (Rrec) of prepared solar cells. The Rct and Rrec values of fabricated solar cell were decreased and increased, respectively in the presence of Fe2+, Cd2+, and Cs+ inorganic cations. As a result, the [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a] perovskites can be considered as the appropriate candidate with high efficiency, stability, and low lead content in the planar perovskite solar cells.

Characteristics of Corrosion Layers and Corrosion Products by Lead Contents of Excavated Bronze Artifacts

This study aims to investigate the corrosion characteristics of bronze artifacts according to lead contents by conducting a comprehensive analysis on corrosion layers and corrosion products focusing on excavated bronze artifacts of ternary alloys with various chemical compositions.</br>From the research outcome, the selective corrosion, high-tin corrosion layers, and lead compounds were identified in two excavated bronze artifacts, and there was a difference in the structure of corrosion layers and the corrosion products of core metal between high lead content bronze and the lowest lead content bronze. Especially, based on the specimen with the highest lead content, it was identified that lead oxide in reddish color and a large quantity of lead corrosion products including lead carbonate in various colors such as white, red, yellow, and green are distributed inside the base metal.</br>In this study, the number of analyzed samples is insufficient to represent the corrosion characteristics of bronze artifacts made of the ternary alloys. Therefore, it is judged that basic data should be accumulated by conducting a corrosion characteristic study on bronze artifacts with various alloy composition ratios in the future.

Relationship between Postural Stability, Lead Content, and Selected Parameters of Oxidative Stress.

This study attempts to determine whether the increased blood lead concentration affects the posturographic test and to determine the relationship between the parameters of posture stability and selected parameters of oxidative stress. The study population consisted of 268 male employees and was divided into two equal subgroups, depending on the lead content in the blood. A posturographic examination was performed. Concentrations of lead, cadmium, zinc protoporphyrin, selected essential elements, and selected markers of oxidative stress in the blood were tested. Higher blood lead concentrations positively affected the values of the sway results: the field and the mean velocity of the center of the feet pressure in posturography. The absolute value of the proprioception ratio was similar in both subgroups. The content of malondialdehyde shows a statistically significantly higher value in a subgroup with high blood lead concentration and exhibits significant correlations only with some of the posturography parameters. The lipofuscin content in erythrocytes correlates with the results of the posturography test. Zinc protoporphyrin, total oxidant status, total antioxidant capacity, selected minerals, and metals did not correlate with the results of the posturography test. In conclusion, posturographic results correlate only with selected markers of oxidative stress, so it can be assumed that the effect on the body balance is only partial.

Water quality criteria and ecological risk assessment of lead (Pb) in China considering the total hardness of surface water: A national-scale study

Site-specific water quality criteria considering hydrochemical conditions are needed for zoning control of environmental risks. However, the differences in water quality parameters between regions have not been fully considered in the current research on water quality criteria and risk assessment of lead. In this study, lead concentration and total hardness (TH) data of surface water in 13 major river basins and 31 administrative regions in China were collected. Based on the normalization of the TH of the toxicity data, the short-term and long-term water quality criteria of lead in China's surface water in the specific TH condition (100 mg/L) were derived using the species sensitivity distribution method, which were 90.7 μg/L and 2.1 μg/L, respectively. Furthermore, this study provided general derivation formulas for the water quality criteria based on the TH of surface water and obtained the site-specific criteria for different regions/basins in China. On this basis, an ecological risk assessment considering the TH was proposed for the first time. The results showed that there was a clear risk of lead in the Pearl River Basin and the rivers in Zhejiang-Fujian. The southern coastal provinces were at an unacceptable risk level, although the lead concentrations in the surface water were medium; the opposite was true in northern China, which meant that a high concentration of lead did not necessarily pose a high ecological risk and about 25 % of the variation in the predicted risk can be explained by the TH in Monte Carlo simulation.

Using pollution indices to develop a risk classification tool for gold mining contaminated soils

The presence of potentially toxic elements (PTEs) in soil and plants is a risk factor to human well-being and the environment. Soil and leaves from a traditional medicinal plant, Vachellia karroo, known as the sweet thorn plant, were assessed to determine the extent of pollution by PTEs from gold mine tailings in a case study area of Matjhabeng Local Municipality, South Africa. A risk classification tool was developed using the different indicators of pollution quantified to describe the pollution risk at each sampling site. High concentrations of copper, cadmium, lead, nickel, and zinc were measured in the soil, which exceeded the maximum permissible soil quality limits. The enrichment factor and geoaccumulation index results also confirmed heavy soil pollution by copper, nickel, and zinc, with exceptionally heavy pollution by cadmium and selenium. The PTEs in the soil were in an exchangeable form, with the sweet thorn plant accumulating lead and selenium at toxic levels, which poses a risk to the health of the local people as the plant is used for medicinal purposes. The overall pollution risk classification tool of the sampling sites showed that 17% were high-risk areas, 53% were moderate-risk areas, and 20% of the sites were low-risk areas.

Adsorption of Pb (II) ion onto Modified Doum Palm (Hyphaene thebaica) Shells: Isotherm, Kinetic and Thermodynamic Studies

The negative impact of high concentrations of lead in the analytical environment on humans and aquatic plants prompted this research. The adsorption of hazardous lead from an aqueous medium using a Modified Doum Palm (MDP) shell was investigated. The modification of the Doum palm shell was supported via 2 M 1: 2 ZnCl2 as activating agent. The batch equilibrium technique was employed to study the effect of initial concentration (800 mg/L), contact time (90 min) and temperature (313 K) on the adsorption capacity of the prepared adsorbent. Experimental data were analyzed using four kinetic models: pseudo-first-order, pseudo-secondorder, intra-particle diffusion and Elovich models and it was found that the pseudo-second-order model fitted the adsorption data most with the highest correlation (R2 = 0.9875). The studies of thermodynamic behaviour revealed negative values for ∆Go (-26.7036 to -28.1252 kJ/mol), and negative values for ∆Ho (-15.5796 kJ/mol) and ∆So (0.03554 kJ/mol/k) respectively. These indicated the adsorption process was exothermic, feasible and spontaneous in the removal of the Pb (II) ion. The findings demonstrated that the adsorbent could be exploited in the removal of Pb (II) ion from an aqueous solution.

CHANGE IN THE CONCENTRATION OF HEAVY METALS IN MUSHROOMS FOR THEIR PRESERVATION

The article presents the results of studies on the concentration of heavy metals in edible mushrooms (Suillus luteus (Lat.), Lactarius deliciosus (Lat.), Armillaria mellea (Lat.), harvested in the conditions of the SE "Vinnytsia Forestry", and the hazard ratio of these toxicants for the human body is determined. The purpose of the research was to study changes in the concentration of heavy metals (lead, cadmium, zinc, copper) in mushrooms during their preservation in marinade. A comparative assessment of the concentration of lead, cadmium, zinc, and copper in fresh and preserved in marinade was carried out. Changes in the concentration of lead, cadmium, zinc, and copper in mushrooms and their hazard ratio during their preservation in marinade are shown. A different intensity of accumulation of heavy metals was revealed by the mushrooms Suillus luteus (Lat.), Lactarius deliciosus (Lat.) and Armillaria mellea (Lat.), collected in the conditions of the studied forest area. It was established that the highest content of lead and cadmium was found in Suillus luteus (Lat.), and zinc and copper in Lactarius deliciosus (Lat.). A lower concentration of lead by 1.14 times, 1.29 and 1.08 times, cadmium – by 1.62 times, 1.68 and 1.4 times, zinc was found in Suillus luteus (Lat.) - 1.2 times, 1.4 and 1.1 times, copper - 1.3 times, 2.2 and 1.8 times, compared to mushrooms before their processing and canning. Similar changes were found in the hazard ratio of lead, cadmium, zinc and copper in mushrooms preserved in marinade. In particular, the hazard ratio of lead, cadmium, zinc, and copper was lower in Suillus luteus (Lat.) by 1.55 times, 1.62, 1.25, and 2.1 times; Lactarius deliciosus (Lat.) - 1.29 times, 1.68, 1.43 and 2.9 times; Armillaria mellea (Lat.) - 1.08 times, 1.4, 1.17 and 1.88 times, respectively, compared to fresh mushrooms.

ОСОБЕННОСТИ НАКОПЛЕНИЯ ТЯЖЕЛЫХ МЕТАЛЛОВ В ЗЕЛЕНОЙ МАССЕ КУСТАРНИКОВ ВИДА BETULA NANA (БЕРЕЗА КАРЛИКОВАЯ) В УСЛОВИЯХ ПОВЫШЕННОЙ АНТРОПОГЕННОЙ НАГРУЗКИ

The features of the distribution and accumulation of heavy metals in the green mass of Betula nana (dwarf birch) shrubs in the territories of the Yamalo-Nenets Autonomous District exposed to anthropogenic load are considered. The relative concentrations of the elements Ni, Cu, Cd, Mn, Zn, Pb in the green mass of shrubs were determined. Elements (Cd, Ni, Mn) with abnormal concentrations in the studied green mass of the conditionally background territory, relative to the clark content in land plants, were identified. The anomalous content of cadmium, zinc and manganese in the Betula nana green mass is characteristic of all the considered areas with increased anthropogenic load, and high concentrations of copper and lead were also found in the area of the unpaved highway near Yar-Sale. Pb has the highest concentration coefficient in the area of a dirt road (11.81), Cd accumulation is most characteristic for the Betula nana cenopopulations near the Obskaya-Bovanenkovo railway (2.4), the highest concentration coefficient for Zn (14.24) was found in the area of the Salekhard-Aksarka highway and GTPP-3. The nature of the distribution of heavy metals from sources is also investigated, among the studied elements, the most distant transfer is characteristic of manganese, and cadmium and copper, on the contrary, are deposited on the territory adjacent to the sources. Conclusions are drawn about the main ways of heavy metals getting into the environment in the region.

Adansonia digitata L. fruit shell extract alleviates lead-induced neurotoxicity in mice via modulation of oxidative stress and a possible chelating activity

BackgroundLead is a ubiquitous environmental heavy metal known to induce neurotoxicity. It has been postulated that substance with high antioxidant capacity could alleviate lead-induced neurotoxicity. Adansonia digitata fruit shell extract (ADFS) has been reported to have high phenolic contents and exerts antioxidant activity. This study investigated the effects of Adansonia digitata fruit shell extract on lead-induced neurotoxicity in mice. MethodsMale balb/c mice (n = 7) were administered with Pb-acetate (50 mg/kg) 30 mins before ADFS (250 mg/kg and 500 mg/kg) or succimer (50 mg/kg) per orally for 28 days. Motor activities were evaluated on days 29 and 30 through horizontal bar and open field tests respectively. Further, spectrophotometry, atomic absorption spectrophotometry and haematoxylin and eosin staining were carried-out to determine the expression of oxidative stress biomarkers, level of lead concentration in the brain and histology of the cerebellum respectively. ResultsLead acetate exposure significantly (p < 0.05) induced motor deficits in horizontal bar test and open field test, caused oxidative stress, high concentration of lead in the brain as well as histological aberration in the cerebellum. ADFS significantly (p < 0.05) reversed the motor deficits evident by increased muscle strength and number of lines crossed. Further, ADFS significantly reversed oxidative stress evident by increased levels of SOD, CAT and GSH and decreased level of MDA. There was also significant (p < 0.05) decrease in brain lead concentration as well as reduced cerebellar cells death. ConclusionFindings suggest that ADFS attenuated motor deficits via inhibition of oxidative stress and chelating activity which is comparable to succimer. Hence, ADFS should be explored for possible development of chelating agent against lead and other heavy metals toxicity.

Effects of lead pollution on bacterial communities in biofilm attached to submerged plants.

Submerged plants and biofilms have significant advantages in hydro-ecology rehabilitation, but their tolerance and physiological responses to heavy metal stress have thus far been under-investigated. This study investigated the influence of lead on physiological and biochemical responses, as well as variation in bacterial communities and functional characteristics of submerged plant biofilms. The results showed that chlorophyll a content of two submerged plants decreased with increased lead concentration. The concentration of malondialdehyde of both submerged plants was higher under high lead concentrations than under low lead concentrations, and the concentrations of malondialdehyde and hydrogen peroxide in Vallisneria natans were more stable. The antioxidant enzyme systems of the two plants played protective roles against lead stress. High lead concentration can inhibit the bacterial community and lead to decreased diversity. The most abundant bacterial phyla were Proteobacteria (40.9%), Cyanobacteria (21.5%), and Bacteroidetes (14.3%). Proteobacteria abundance decreased with increased lead concentration, while Cyanobacteria abundance increased. The lead concentration in plants (19.7%, P < 0.01) and the lead concentration in aquatic environment (17.7%, P < 0.01) were significantly correlated with variation in bacterial communities. High lead concentration inhibits the activity of these bacteria related to the conversion of nitrogen and sulfur.

Nerium oleander L. as a Phytoremediation of Heavy Metals in Diyala Governorate – Iraq

The study samples were collected during the months of April and May 2022, samples were collected from different regions in Diyala Governorate – Iraq. The study aimed to assess the role of oleander plant in the phytoremediation of heavy metals (lead , cadmium , arsenic and selenium) within Diyala Governorate by estimating their concentration in the leaves of the plant and the soil on which it grows as well as calculating the bioaccumulation factor (BAF). Al-Muqdadiyah Industrial area was one of the most polluted areas with lead, the highest concentration of lead appeared in the leaves of the oleander plant grown in this area, as well as the soil on which it grows (2.452 and 0.904 ) ppm respectively. The highest concentration of cadmium was recorded for oleander leaves in the old city of Baqubah (2.208ppm), while the highest concentration appeared in the soil on which it grows in the Al-Muqdadiyah Industrial area (0.363ppm). The Al-Muqdadiya industrial area also recorded the highest concentration of arsenic in the leaves of the oleander plant ( 0.559 ppm) ,but the highest concentration in the soil on which it grows was in the central city of Al-Muqdadiyah (0.218ppm) , followed by the industrial city off Al-Muqdadiyah.( 0.132ppm) . The highest concentration of selenium appeared in the industrial city of Al-Muqdadiya in both the leaves of the oleander plant and the soil on which it grows (0.441 and 0.104) ppm. The value of the bioaccumulation factor (BAF) shows the efficiency of the oleander plant in the phytoremediation of cadmium, followed by lead, arsenic and selenium in varying proportions. Keywords : Phytoremediation , Neium oleander , Heavy metals DOI: 10.7176/JEES/12-9-04 Publication date: September 30 th 2022