Heavy Metals Cadmium Research Articles

Assessement of the Influence of Baking Fuel Types on the Residues of Some Heavy Metals in Selected Bread from Jalingo, Taraba State

Method of food processing and handling plays pivoted role in its contamination. This research was geared towards assessing the level at which food handling and production processes influence metallic contamination. Samples of flour and baked bread (electric or coal oven) were sourced from market and bread bakeries within Jalingo metropolis. Heavy metals (Lead, Cadmium, Chromium, Nickel, Iron, and Zinc) analysis of the samples was done using Atomic Absorption Spectrophotometer (AAS). Bread baked using coal oven were observed to show elevated level of metallic contamination over those baked using electric oven with Iron (Fe) showing a statistical significant increase at p<0.05 while Cadmium (Cd) was not detected in bread baked using both fuel source. Both electric and coal baked bread were analyzed to have more metallic deposition when compared to the flour. Although, the heavy metals contamination were within the range of FAO/WHO permissible limit but long term consumption of such food products could lead to bioaccumulation in the biological system and becomes injurious to health.

Dual resistance to heavy metals and antibiotics of Aeromonas hydrophila isolated from Carassius carassius (Linnaeus, 1758) in Lake Tonga, Algeria

Aeromonas hydrophila, a bacterium with significant virulence potential, is the predominant pathogenic bacteria naturally infecting fish. This study aims to identify the antibiogram and heavy metal resistance pattern of Aeromonas hydrophila obtained from both Carassius carassius fish and their surrounding water environment in Lake Tonga, Algeria. A total of 59 strains of Aeromonas hydrophila were isolated from 168 Carassius carassius samples and 144 waters samples of Lake Tonga. All the strains were tested for resistance to 13 antibiotics and three types of heavy metals (Cobalt, copper and cadmium) using disk diffusion and two-fold agar dilution method, respectively. Clinical macroscopic examination of the fish was also carried out. More than 14% of the examined fishes showed the characteristic clinical signs. Drug screening showed high levels of resistance to β-lactam antibiotics, 100% of the strains were resistant to ampicillin followed by cefalotin (91.53%) and ticarcillin (88.14%). More than 40% of the strains exhibited resistance against gentamicin, amikacin and chloramphenicol. The multiple antibiotic resistance (MAR) indexing of A. hydrophila strains showed that all of them originated from high-risk sources. Among tested heavy metals, bacterial isolates exhibited resistant pattern of Co>Cu >Cd. A positive correlation was observed between antimicrobial resistance and metal tolerance (Odds Ratio>0.1). These resistant profiles could be useful information to avoid unnecessary use of chemical and antimicrobial products in the aquatic environment and to provide a novel approach to manage bacterial infection in fish.

Ecological and Health Risk Assessment of Heavy Metals Bioaccumulation in Ganges Fish Near Varanasi, India.

Heavy metal contamination in river Ganga is one of the factors for deterioration in its water quality and also adds to human health risks. We designed our study to achieve a holistic approach by not only estimating the concentration of heavy metals (lead, manganese, chromium, and cadmium) in the river water at different sites based on human anthropogenic activities but also in the fishes residing in the same sites that are collected for human consumption on daily basis. We found that Ganga River in Varanasi is highly loaded with metals (PLI = 6.698). Mean concentration in water was 1.29mg/L for Pb, 1.325mg/L for Mn, 0.169mg/L for Cr, and 0.161mg/L for Cd, which were above the permissible limits stated by Environment Protection Agency (EPA) in drinking water. Fish, including exotic and invasive species, were collected from the wild and were processed for the presence of these metals in their tissues. Degree of heavy metal concentration followed liver > gills > muscles. The highest accumulation of Pb was observed in Carpio (Cyprinus carpio) liver (8.86µg/g) and lowest in Baikari (Clupisoma garua) muscles (0.07µg/g). Total target hazard quotient (THQ) value, i.e., hazard index (HI) showed values in following sequence: Cyprinus carpio > Oreochromis niloticus > Channa gachua > Johnius coitor > Mastacembelus armatus > Mystus tengara > Clupisoma garua. Maximum HI value was recorded in C. carpio, which is highly consumed fish by humans, hence, may be harmful to them.

Prospects for the use of layer-by-layer technology for the development of an enzyme biosensor used for milk quality control

This article presents the results of scientific research on the development of a biosensor system for the determination of salts of heavy metals (cadmium and lead) in milk. When developing a biosensor system, much attention is paid to the selection of biological material and the method of their stabilization using physical and chemical forces, namely, immobilization. In this regard, studies were carried out on the selection of the enzyme and the method of its immobilization in the development of a biosensor for the detection of salts of heavy metals in milk. The development of a biosensor for the determination of toxic elements in food products is of scientific and practical importance. In world practice, special attention is paid to the contamination of raw materials and food products with toxic chemicals, mainly of anthropogenic origin, which are persistent organic pollutants. Therefore, quality control of raw materials, food products is important for consumers, and, accordingly, for the food industry. Experimental studies are based on the methods of Filippova A. M., Vorobieva O. V. to determine the specific activity of the enzyme acetylcholinesterase. Determination of the activity of the catalase enzyme was carried out in accordance with the gasometric method according to the method of Warburg. As a result of experimental studies, the catalase enzyme as a biological material was chosen as a sensitive element. As a carrier for the immobilization of enzymes, a 5-bilayer combination of "chitosan-sodium alginate" was selected. The layer-by-layer technology was used to immobilize the enzyme on the substrate surface when creating an enzyme biosensor. The results of the research are recommended to be applied in the study of food safety issues and in the assessment of safety indicators of raw materials and food products by the express method.

Removal of Diclofenac and Heavy Metal Ions from Aqueous Media Using Composite Sorbents in Dynamic Conditions.

Pharmaceuticals and heavy metals pose significant risks to human health and aquatic ecosystems, necessitating their removal from water and wastewater. A promising alternative for this purpose involves their removal by adsorption on composite sorbents prepared using a conventional layer-by-layer (LbL) method or an innovative coacervate direct deposition approach. In this study, four novel composite materials based on a silica core (IS) and a polyelectrolyte coacervate shell were used for the investigation of dynamic adsorption of three heavy metals (lead, nickel and cadmium) and an organic drug model (diclofenac sodium salt, DCF-Na). The four types of composite sorbents were tested for the first time in dynamic conditions (columns with continuous flow), and the column conditions were similar to those used in wastewater treatment plants. The influence of the polyanion nature (poly(acrylic acid) (PAA) vs. poly(sodium methacrylate) (PMAA)), maintaining a constant poly(ethyleneimine) (PEI), and the cross-linking degree (r = 0.1 and r = 1.0) of PEI chains on the immobilization of these pollutants (inorganic vs. organic) on the same type of composite was also studied. The experiments involved both single- and multi-component aqueous solutions. The kinetics of the dynamic adsorption process were examined using two non-linear models: the Thomas and Yoon-Nelson models. The tested sorbents demonstrated good adsorption capacities with affinities for the metal ions in the following order: Pb2+ > Cd2+ > Ni2+. An increase in the initial diclofenac sodium concentration led to an enhanced adsorption capacity of the IS/(PEI-PAA)c-r1 sorbent. The calculated sorption capacities were in good agreement with the adsorption capacity predicted by the Thomas and Yoon-Nelson models. The substantial affinity observed between DCF-Na and a column containing composite microparticles saturated with heavy metal ions was explained.

Ameliorating Effects of Graphene Oxide on Cadmium Accumulation and Eco-Physiological Characteristics in a Greening Hyperaccumulator (Lonicera japonica Thunb.).

Graphene oxide (GO), as a novel carbon-based nanomaterial (CBN), has been widely applied to every respect of social life due to its unique composite properties. The widespread use of GO inevitably promotes its interaction with heavy metal cadmium (Cd), and influences its functional behavior. However, little information is available on the effects of GO on greening hyperaccumulators under co-occurring Cd. In this study, we chose a typical greening hyperaccumulator (Lonicera japonica Thunb.) to show the effect of GO on Cd accumulation, growth, net photosynthesis rate (Pn), carbon sequestration and oxygen release functions of the plant under Cd stress. The different GO-Cd treatments were set up by (0, 10, 50 and 100 mg L-1) GO and (0, 5 and 25 mg L-1) Cd in solution culture. The maximum rate of Cd accumulation in the roots and shoots of the plant were increased by 10 mg L-1 GO (exposed to 5 mg L-1 Cd), indicating that low-concentration GO (10 mg L-1) combined with low-concentration Cd (5 mg L-1) might stimulate the absorption of Cd by L. japonica. Under GO treatments without Cd, the dry weight of root and shoot biomass, Pn value, carbon sequestration per unit leaf area and oxygen release per unit leaf area all increased in various degrees, especially under 10 mg L-1 GO, were 20.67%, 12.04%, 35% and 28.73% higher than the control. Under GO-Cd treatments, it is observed that the cooperation of low-concentration GO (10 mg L-1) and low-concentration Cd (5 mg L-1) could significantly stimulate Cd accumulation, growth, photosynthesis, carbon sequestration and oxygen release functions of the plant. These results indicated that suitable concentrations of GO could significantly alleviate the effects of Cd on L. japonica, which is helpful for expanding the phytoremediation application of greening hyperaccumulators faced with coexistence with environment of nanomaterials and heavy metals.

Calcium Activation of the Androgen Receptor in Prostate Cells.

Although prostate cancer patients initially respond to androgen deprivation therapy, most patients progress to a resistant phenotype. Castration resistance is due, in part, to intratumoral and/or adrenal synthesis of androgens, overexpression or mutation of the androgen receptor (AR), stabilization of AR by chaperones, and ligand-independent activation of AR. Increasing evidence also links disruption of calcium homeostasis to progression of prostate cancer. Our previous study shows that heavy metal cadmium activates the AR through a ligand-independent mechanism. Cadmium mimics calcium in biological systems due to their similar ionic charge and radius. This study determines whether calcium activates AR and whether first- and second-generation antiandrogens block the ability of calcium to activate the receptor. The expression of androgen-responsive genes and calcium channels was measured in prostate cells using a quantitative real-time polymerase chain reaction assay. Cell growth was measured. To ask whether calcium activates AR, prostate cells were treated with calcium in the absence and presence of the first-generation antiandrogens hydroxyflutamide and bicalutamide and the second-generation antiandrogen enzalutamide, and the expression of androgen-responsive genes and cell growth was measured. In the normal PWR-1E cells and HEK293T cells transiently expressing AR, treatment with calcium increased the expression of androgen-responsive genes by approximately 3-fold. The increase was blocked by enzalutamide but was not consistently blocked by the first-generation antiandrogens. In LNCaP cells which contain a mutant AR, treatment with calcium also increased the expression of androgen-responsive genes by approximately 3-fold, and the increase was more effectively blocked by enzalutamide than by hydroxyflutamide or bicalutamide. Treatment with calcium also increased cell growth that was blocked by enzalutamide. To ask whether dysregulation of calcium channels is associated with castration resistance, calcium channels were measured in the normal PWR-1E prostate cells, the hormone-responsive LNCaP cells, and the castration-resistant VCaP and 22RV1 cells. Compared to normal prostate cells, the hormone-responsive and hormone-resistant cells overexpressed several calcium channels. The results of this study show that calcium activates AR and increases cell growth and that calcium channels are overexpressed in hormone-responsive and hormone-resistant prostate cancer cells. Taken together, the results suggest a novel role of calcium in the castration-resistant phenotype.

Dual Benefits of Hydrogel Remediation of Cadmium-Contaminated Water or Soil and Promotion of Vegetable Growth under Cadmium Stress.

This study aims to solve the problem of cadmium heavy metal ion pollution caused by the abuse of chemical fertilizers and activities such as mining, which pose a serious threat to the plant growth environment. We successfully synthesized DMAPAA (N-(3-(Dimethyl amino) propyl) acrylamide)/DMAPAAQ (N, N-Dimethyl amino propyl acrylamide, methyl chloride quaternary) hydrogels via free radical polymerization. Subsequently, we conducted experiments on this hydrogel for growing vegetables under cadmium stress conditions in aqueous solutions and soil. The cadmium capture capacity of DMAPAA/DMAPAAQ hydrogels under different cadmium ion concentrations and pH values was evaluated by using inductively coupled plasma optical emission spectrometry (ICP). The research results show that under the condition of pH = 7.3, the cadmium capture capacity of DMAPAA/DMAPAAQ hydrogels is the greatest. We used the Langmuir model to fit the adsorption data, and the correlation coefficient was as high as 0.96, indicating that the model fits well. The application of the hydrogels promoted the growth of vegetables in soil under cadmium stress conditions. The results showed that when the added amount of hydrogel was 4%, the dry weight of the vegetables was the largest. In addition, when the added amount of cadmium was 500 mg/kg and the added amount of hydrogel was 4%, the absorption of cadmium by the vegetables decreased to an undetectable level. In summary, the hydrogel successfully synthesized in this study can be effectively used to immobilize cadmium ions in soil while positively promoting the growth and yield of vegetables. This achievement has practical significance for solving the problem of heavy metal ion pollution.

Evaluation of Heavy Metal Pollution in Commonly Consumed Mollusc (Crassostrea gasar) from Elechi Creek, River State, Nigeria and the Health Risk Implications

Marine biotas are used to assess potential adverse human health risks associated with consuming protein-rich aquatic organisms. Heavy metal content of Mangrove oysters (Crassostrea gasar) was evaluated between January and June 2022 in 3 stations. Six heavy metals (copper, cadmium, zinc, lead, arsenic and iron) were determined using standard methods. Target Hazard Quotient (THQ) and Hazard Index (HI) were used for the non-carcinogenic assessment while Target Cancer Risk (TR) was used for the carcinogenic assessment of the potential human health risk of consuming the oysters. The heavy metal values recorded were Cu (473.2 – 596.7 mg/kg), Cd (2.33 – 3.84 mg/kg), 209.02 – 246.41 mg/kg), Pb (6.16 – 12.07 mg/kg), As (0.012 – 0.016 mg/kg) and Fe (1609.0 – 1846.0 mg/kg). All the heavy metals were above the acceptable limits except arsenic. Stations 2 and 3 had relatively higher values; attributed to anthropogenic activities. The THQ and HI values were less than 1 in all the metals and stations while TR for Pb and arsenic were within the negligible range in all the stations. However, Cd was unacceptable among the children in station 2. Station 3 had relatively higher values while the children were more vulnerable to both non-carcinogenic and carcinogenic risks. In conclusion, the consumption of oysters from Elechi Creek is considered safe based on acceptable levels of the THQ, HI and TR; though Cd-TR for children (Station 2) was unacceptable.

Potential Protective Effects of Spirulina (Spirulina platensis) against In Vitro Toxicity Induced by Heavy Metals (Cadmium, Mercury, and Lead) on SH-SY5Y Neuroblastoma Cells

Spirulina, a filamentous microalga, is used all over the world as a nutraceutical dietary supplement. Recent studies have focused on examining its chelating activity and antioxidant properties, especially as a candidate for protection against neurotoxicity caused by heavy metals. The MTT test and LDH assay were used to examine the viability of the SH-SY5Y cells for 24, 48, and 72 h, to Cd, Hg, and Pb, individually or in combination with Spirulina, and the effects of necrotic cell death. In comparison to the control group, the viability of SH-SY5Y cells decreased after 24 h of exposure, with Cd being more toxic than Hg and Pb being less lethal. The effects of heavy metal toxicity on cell survival were ranked in order after 72 h under identical experimental circumstances as follows: Hg, Pb, and Cd. The viability of the cells was then tested after being exposed to Spirulina at doses of 5 at 50 (%v/v) for 24, 48, and 72 h, respectively. SH-SY5Y cells that had been treated with mixtures of heavy metals and Spirulina underwent the same assay. Cell viability is considerably increased by using Spirulina treatments at the prescribed periods and doses. Instead, the same procedure, when applied to SH-SY5Y cells, caused the release of LDH, which is consistent with the reduction in cell viability. We demonstrated for the first time, considering all the available data, that Spirulina 5, 25, and 50 (%v/v) enhanced the number of viable SH-SY5Y cells utilized as a model system for brain cells. Overall, the data from the present study provide a first insight into the promising positive role of Spirulina against the potentially toxic effects of metals.

Bioaccumulation of some Heavy Metals (Cadmium, Copper and Zinc) in Three Tissues of the Common Carp Cyprinus carpio L. Collected from a Mud Culture

The current study was conducted to find out the bioaccumulation of the three elements cadmium, copper and zinc, in tissues of the common carp Cyprinus carpio L., they were gills, muscles and viscera. Cultivated in three mud ponds in Thi Qar Governorate - Nasiriyah city, Shatrah district, in the village of Al-Ajjah Al-Buhan, near Al-Ghamouqa Valley, it is 55 km away from the center of Al-Nasiriyah. The fish were distributed to the lakes with uniform densities for the period from 5/11/2022 to 5/4/2023, by 1000 fish/m3 were used, it was divided into three lakes equally, with an average weight of 20 gm. A standard local diet was used to feed the fish, standard methods were used to estimate the concentrations of heavy metals in tissues, by a flame atomic absorption spectrometer. Results were recorded in tissues for cadmium in gills, muscles and viscera. The highest values were in the autumn season for gills and muscles, respectively (12.13-12.77 μg/gm dry weight). The highest concentration recorded in spring for tissues was (8.3 μg/gm dry weight). Copper recorded the highest value in gills, muscles and viscera, in the spring season (222.14, 334.77 and 110.65μg/gm dry weight), respectively. Zinc recorded high concentrations in the gills, viscera, and muscles, i In autumn (350.34, 259.17 and 303.34 μg/g dry weight), respectively. The results showed that the accumulation of elements; Heavy was in the following order: Zinc > copper > cadmium. Cadmium: gills > viscera > muscles. Copper: gills > muscles > viscera. Zinc: gills > viscera > muscles.

Isolation and identification of bacteria from solid waste deposit sites for the degradation of heavy metals

Heavy metals from solid waste deposits that are toxic, mutagenic, and carcinogenic contaminate natural water supplies and agricultural environments. The purpose of this project is to separate and characterize naturally occurring bacteria that can reduce and detoxify heavy metals (lead, cadmium, nickel, zinc, manganese, iron, copper, chromium, and mercury) from solid waste dumping sites. Ten strains in total were isolated from the samples; the two best-performing isolates, Shewanella oneidensis strain AGB 4 (Isolate 5) and Bacillus pumilus strain AGB 11 (Isolate 6) were recognized up to the genus level based on their 16S rRNA identification studies. These isolates demonstrated resistance to every heavy metal that was examined in the solid waste. The MICs for the two isolates varied in relation to the amounts of the heavy metals listed above. The solid waste isolates grew best at pH 7.0, 30°C and an incubation period of 24 hours. Utilizing an atomic absorption spectrophotometer to measure degradation potential, Shewanella oneidensis demonstrated the most removable capability for copper (60%) and the lowest removable capability for lead, arsenic and mercury (45%) and Bacillus pumilus demonstrated a reduction of 48% in mercury and arsenic and 65% in copper. Bacillus pumilus and Shewanella oneidensis may be able to break down heavy metals through plasmids, which could be used to change plasmids so they can carry the ability to accumulate heavy metals. Thus, determining the resistance to heavy metals and biodegradation potential of two bacteria could serve as a foundational investigation for the development of viable local biological remediation agents in solid waste deposit sites.

Assessment of heavy metal impact on two species of ciliate protozoa

In the present study toxic effect of heavy metals (Chromium, Cadmium and Lead) was observed in two species of ciliated Protozoa (Dreponomonas and Colpoda species). Both Protozoa were collected from agriculture field of Madhepura district. Heavy metal salt used in this study were CrCl 6H 0, CdCl and * 2 2 Pb(NO ) . Lethal concentration dose (LC ) for 50% survival of Protozoa population was estimated with 3 2 50 different concentration of heavy metal salt using Sedge-Wick-Rafter chamber. The effect of metal salt on Protozoa was monitored with binocular microscope at every 10 minutes. The order of toxicity in both species was observed as Cr>Cd>Pb.. KEYWORDS :Ciliated Protozoa, Toxicity, Heavy metals, Lethal dose (LC )

Comparison of leaching behaviour of heavy metals from sediments sampled in sewer systems - environmental and public health aspect.

The article analyzes the content of heavy metals and standard physical as well as chemical pollution indicators in different types of sediments from stormwater, combined sewer and sanitary sewer systems. Nickel, lead, chromium, copper, zinc and cadmium, as well as standard physical and chemical pollution indicators, were determined in sewage sediments. Aqueous extracts of sediments samples, taken from storm water sewer inlet sediments traps, storm sewers, sanitary sewers and combined sewers, were prepared in accordance with PN-EN 12457-2:2006. After mineralization, the concentrations of the metals: nickel, lead, chromium, copper, zinc and cadmium in the extracts were determined using the inductively coupled plasma emission spectroscopy technique. The results were analyzed with a non-metric multidimensional scaling algorithm. The heavy metal content was variable depending on the sediments collection site. The heavy metals nickel, lead, chromium, copper, zinc and cadmium were found in the sediments from stormwater inlets, storm sewer and sanitary sewer channels, with variability in the concentration of individual metals. The sediments from the flushing of sanitary sewers and combined sewers did not contain cadmium. The content of heavy metals in sediments varied depending on the sampling location and type of sewer system, indicating the need for detailed monitoring to identify the sources of emissions. Sediments from stormwater sewers have higher concentrations of heavy metals, with those from sewer inlets showing zinc concentrations exceeding regulatory limits, highlighting the variability and potential environmental impact of different sewer systems.

Assessment of some heavy metal content in sediments of a mangrove swamp, niger delta, nigeria using applicable ecological risk indices

Sediments can act as pollutant sinks and a source of pollution in aquatic environments. The surface sediments of the Isaka–Bundu tidal swamp, Niger Delta was assessed for heavy metal content using standard methods and assessment indices. The study was carried out in three stations between January and June 2022. Five heavy metals (lead, copper, cadmium, nickel and zinc) were evaluated while eight assessment indices (Contamination Factor - CF, degree of contamination - DC, Ecological Risk - Er, Potential Ecological Risk - PERI, Pollution Load Index - PLI, Enrichment Factor - EF, Geo-accumulation Index - Igeo and Quantification of Contamination -QoC) were applied. Results showed that cadmium and copper exceeded permissible limits while lead, zinc and nickel were within limits. Stations 1 and 3 recorded significantly higher values indicating anthropogenic influence. The dominant anthropogenic activities observed in the area include maritime and dockyard activities and artisanal crude oil refinery. The assessment indices showed that the sediments were at various levels of heavy metal pollution mainly influenced by copper and cadmium viz: CF: Cu (considerable degree) and Cd (very high degree), DC (very high degree), Er: Cd (high ecological risk) and Cu (very high ecological risk), PERI (significant high ecological risk), PLI (very high level pollution), EF: Pb, Zn, Cu (Station 1) and all Cd (extremely high enrichment), Igeo: Cd (extremely polluted) and QoC: Cu and Cd (anthropogenic source). The sediments were highly polluted with toxic metals, which is detrimental to humans and aquatic biota.Keywords: Heavy metal; Indices; Mangrove; Niger Delta; Sediment.

Swift Removal of the Heavy Metals Cadmium and Lead from an Aqueous Solution by a CAN-Zeolite Synthesized from Natural Clay

CAN-zeolite was synthesized with a high purity from natural kaolinite via alkali fusion by hydrothermal treatment at a pressure of 1 kbar H2O. It was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy and nitrogen adsorption at 77 K. The results show that after AK hydrothermal treatment (under specific conditions), the SBET increases from 5.8 m2g−1 to 30.07 m2g−1 which is six times greater. The AK which was a non-porous or macroporous solid (the nitrogen adsorption/desorption of AK is of type II) became mesoporous (N2 adsorption–desorption isotherms exhibit typical hysteresis of type IV) with a pore size of 5.9 Å. XRD of AK shows the presence of quartz (Q) as impurities, and illite and kaolinite as major fractions; after hydrothermal treatment, the XRD diffractogram shows only fine pics related to CAN-zeolite (with a good crystallinity), confirming the success of the synthesized process. These results suggest that the synthesized CAN-zeolite has the potential to be tested in the removal of heavy metals from waste water as part of a remediation process. Batch reactors were used to evaluate the adsorption isotherms and kinetic studies of heavy metals, cadmium, and lead, by natural kaolinite clay (AK) and synthesized cancrinite zeolite (CAN-zeolite). The results show that the adsorption kinetics of the bivalent heavy metals cadmium and lead are extremely fast with either AK or CAN-zeolite. Equilibrium was reached within 2 min. Adsorption isotherms show that the synthesized CAN-zeolite has a higher adsorption capacity; the retention capacity of lead and cadmium was three times greater than that presented by the natural clay mineral. According to the findings, CAN-zeolite has a higher affinity for PbII (192 mg/g) compared to CdII (68 mg/g). The negative reactive surface sites interacting with these cationic heavy metals resulted in a higher amount of heavy metals adsorption than the cation exchange capacity (CEC). The adsorption information was analyzed using the Langmuir and Freundlich equations. The Langmuir model provided a good fit to the equilibrium data, indicating a monolayer adsorption mechanism.

Chemical risk assessment of conventionally and organically grown tomatoes in Côte d'Ivoire

Background: The use of fertilizers in agriculture can be a source of contamination of fruits and vegetables. Aims: This study was to assess the level of contamination of tomatoes by heavy metals (Pb, Cd, Hg, and As), in order to assess the risks of exposure of consumers of tomatoes in Côte d'Ivoire. Material and Methods: More specifically, the assessment focused on the contamination by heavy metals used intensively by producers for the fertilization of vegetable crops. Four heavy metals (mercury, lead, cadmium and arsenic) were tested in tomato samples from both types of agriculture. Results: The average level of mercury in organic tomatoes (0.08290 ± 0.03 mg/kg) and in conventional tomatoes (0.1564 ± 0.1 mg/kg) exceeded the maximum limit (EC N 1881/2006). However, in organic tomatoes, only mercury level exceeded the required standard, the other heavy metals being present in trace amounts. The content of these other metals in the organic tomatoes exceeded the standard. However, the ratio (hazard quotient) of the weekly heavy metal intake to the provisional tolerable weekly intake for all heavy metals was less than one (1). Conclusion: Consumption of tomatoes from the areas in this study did not pose a health risk to the consumer. Keywords: Organic agriculture, conventional agriculture, heavy metals, dietary exposure.

Investigation of possible heavy metal contaminants of Zingiber officinale rhizomes and Allium sativum bulbs sourced from a market in Enugu State of Nigeria using rat models

Natural products such as plants, animals, microorganisms, and aquatic organisms have been employed by humans from ancient time for treatment and prophylaxis of diseases. In the last decade, attention is being diverted towards traditional medicine partly due to high cost of synthetic and semi-synthetic drugs, increase in multidrug resistant disease causing microorganisms, and unavailability of certain drugs. A major limitation is heavy metal contamination. This study is aimed at investigating the possible heavy metal contaminants of Zingiber officinale rhizomes and Allium sativum bulbs sourced from a market in Enugu State of Nigeria using rat models. Phytochemical analysis and acute toxicity studies were done according to standard methods with slight modifications. The Atomic Absorption Spectroscopy (AAS) technique was used for extraction and assay of the possible heavy metal contaminants. The phytochemicals in Zingiber officinale were alkaloids, tannins, flavonoids, steroids and terpenoids and those of Allium sativum were alkaloids, saponins, flavonoids, and glycosides. The actual lethal doses (actual LD50) of Zingiber officinale, Allium sativum and combination of the two were 8,660, 4,472, and 5,477 mg/kg body weight respectively. The respective amounts of the tested heavy metals (lead, cadmium, mercury, chromium and arsenic) present in the samples were 0.041, 0.082, 0.084, 0.061 and 0.041 ppm in Zingiber officinale and 0.012, 0.018, 0.039, 0.045 and 0.030 ppm in Allium sativum. These were below the WHO permissible limits. This study therefore concluded that heavy metals contamination of herbal products are inevitable but can be controlled and minimized to WHO acceptable limit.

Metal and pesticide residues levels accumulated in leafy vegetables and several fragrant medicinal plants in Baghdad Governorate / Iraq

The levels of some heavy metals (cadmium, lead, chromium) and pesticide residues (Malathion, Dimethoate, Profernofoes, PrimiohosMe) were estimated in some aromatic medicinal plants (chamomile, anise seeds, coriander, fennel) and leafy vegetables (cabbage, celery, grape leaves, and coriander, Mint, lettuce, spinach, and watercress) are commonly used and collected frm various markets. Organophosphorus pesticides have also been detected in some aromatic medicinal plants and leafy vegetables. Where, chamomile samples showed only Malathion, while in coriander malathion is 0.86 and Dimethoate have been detected in Anise seeds, profernofoes in chamomile were predominant, and leafy vegetables have also been detected some Organophosphorus pesticides in green mint Malathion, profernofoes is dominant, the findings showed that some heavy metals were present in some of the samples that were collected. Lead and chromium levels, as well as varying amounts of cadmium and chromium, were found in grape leaves in the majority of the samples that were examined. Samples of chamomile flowers had the greatest average amounts of cadmium and chromium, whereas samples of anise seeds had the highest levels of lead.

MiR397b-LAC2 module regulates cadmium stress response by coordinating root lignification and copper homeostasis in Arabidopsis thaliana

Non-essential heavy metal cadmium (Cd) is toxic to plants and animals. Cadmium affects plant photosynthesis, respiration, and causes water imbalance and may lead to plant death. Cadmium induces toxicity by interfering with the essential metal copper (Cu) homeostasis, which affects plant nutrition. Though root lignin biosynthesis is positively regulated by Cd stress, the underlying mechanisms promoting lignin accumulation and controlling Cd-induced Cu limitation responses are unclear. Here, we elucidated the role of Cu-responsive microRNA (miR397b) in Arabidopsis thaliana plants for Cd stress by targeting the LACCASE2 (LAC2) gene. This study demonstrated the fundamental mechanism of miR397b-mediated Cd stress response by enhancing the lignin content in root tissues. We developed miR397b over-expressing plants, which showed considerable Cd stress tolerance. Plants with knockdown function of LAC2 also showed significant tolerance to Cd stress. miR397b overexpressing and lac2 mutant plants showed root reduction, higher biomass and chlorophyll content, and significantly lower Reactive Oxygen Species (ROS). This study demonstrated the miR397b-mediated Cd stress response in Arabidopsis by enhancing the lignin content in root tissues. We conclude that modulation in miR397b can be potentially used for improving plants for Cd tolerance and Cu homeostasis.