Amount Of Cd Research Articles

Main Control Factors of Cadmium Content in Rice in Carbonate Rock Region of Guangxi Based on the DGT Technique

In order to explore the main controlling factors of Cd enrichment in rice under a geological high background in the Guangxi carbonate rock area, this study was based on rice grain-root soil samples from the carbonate rock areas in the southwest and north of Guangxi. Combined with diffusive gradients in thin films technology (DGT), the relationship between soil pH, organic matter, cation exchange capacity (CEC), DGT-Cd, and ω(rice-Cd)-BCF value in rice grains was analyzed and discussed. The main factors were determined by principal component analysis, and a quantitative model was established. The results showed that the average value of ω(soil-Cd) was 0.975 mg·kg-1, and the over-standard rate was 33.33%; the average value of ω(rice-Cd) was 0.020 mg·kg-1, and the average BCF value was 0.038, and the over-standard rate of Cd content in rice grains was 4.2%. The content of Cd in paddy soil was high, but bioavailability was low in the study area. The BCF value of rice grains in the study area was significantly negatively correlated with soil pH and cation exchange capacity at the level of 0.01, positively correlated with DGT-CD at the level of 0.01, and negatively correlated with organic matter at the level of 0.05. The results of principal component analysis showed that the total amount of Cd in the soil, pH, and DGT-Cd were the main factors affecting the accumulation of Cd in rice in the Guangxi carbonate rock area. Taking the total amount of Cd in the soil, pH, and DGT-Cd as variables, the fitting equation of BCF value of rice grains in the Guangxi carbonate rock region was established, and the determination coefficient of the model was 0.717, which could better predict the content of Cd in rice grains in this region.

Three-dimensional graphene/amino-functionalized metal-organic framework for simultaneous electrochemical detection of Cd(II), Pb(II), Cu(II), and Hg(II).

Trace detection of multiple toxic heavy metals is a very important and difficult problem, conveniently, sensitively, and reliably. In this work, we developed an innovative electrochemical sensor for simultaneously detected heavy metal ions (Cd2+, Hg2+, Cu2+, and Pb2+). In order to detect trace amounts of Cd(II), Pb(II), Cu(II), and Hg(II) in food quickly, accurately, and at low cost, this study used electrochemical reduction to prepare a screen-printed electrode (3DGO) modified with 3DGO and UiO-66-NH2 composite nanomaterials (UiO-66-NH2/SPCE). The sensing platform is composed of three-dimensional graphene (3DGO), aminated UiO-66 metal-organic framework, named 3DGO/UiO-66-NH2. It is worth noting that the porous structure, amino functional groups on the surface, and large specific surface area of UiO-66-NH2 can enrich and promote the absorption of heavy metal ions. 3DGO was introduced to improve the electrochemical activity and conductivity of UiO-66-NH2 material. The construction of this new sensing platform, which can synchronously, reliably, and sensitively simultaneously detect Cd2+, Pb2+, Cu2+, and Hg2+ only in 150s in the linear range of 0.01-0.35pM with the detection limitations, is 10.90 fM, 5.98 fM, 2.89 fM, and 3.1 fM, respectively. This method provides a new strategy that uses MOF materials for electrochemical detection of a variety of heavy metal ions in food.

Immobilization mechanism of Cd2+/HCrO4-/CrO42- ions and carboxin on montmorillonite modified with Rhizobium leguminosarum bv. trifolii exopolysaccharide

The modification of clay minerals by exopolysaccharides (EPSs) may significantly increase their adsorption capacity. Therefore, this study focused on the impact of the EPS synthesised by the soil bacterium Rhizobium leguminosarum bv. trifolii on the adsorptive features of montmorillonite relative to two heavy metal ions (cadmium/Cd(II) and chromium/Cr(VI)) and a pesticide (carboxin). The characterization of montmorillonite was carried out using various methods: X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy. The adsorption/desorption data were modelled using theoretical equations (Langmuir-Freundlich, Redlich-Peterson, etc.). The obtained results showed that EPS promoted the accumulation of heavy metals on the clay mineral and, simultaneously, contributed to a lower degree of their desorption. This resulted from complexation between the biopolymer and the Cd(II)/Cr(VI) ions. After montmorillonite modification with 100 mg/L EPS, the maximum noted growth in Cd(II) adsorption was 26.10%, whereas it was 20.30% for Cr(VI). The adsorbed amounts of Cd(II) and Cr(VI) were then 24.24 and 14.45 mg/g, respectively. In the case of carboxin, the EPS effect on its adsorption/desorption rates was opposite – its adsorption level decreasing by 10.80%, was 0.27 mg/g. Thus, the presence of EPS-producing bacteria could reduce the bioavailability of the heavy metals, but not of the selected pesticide.

Nitric Oxide Alleviates Photochemical Damage Induced by Cadmium Stress in Pea Seedlings

Cadmium (Cd), a life threatening hazardous heavy metal is abundant in nature. Cd amounts are greater in leaves than other plant parts, and it shows considerable effects on photosynthesis. Nitric oxide (NO), a free radical present in living organisms, is now known as an important signaling molecule playing various physiological processes in plants. In this study, the possible ameliorative effect of NO on photosynthesis was examined on pea seedlings grown under Cd stress. Results showed that chlorophyll, net photosynthetic rate, transpiration rate, stomatal conductance, photochemical efficiency of Photosystem II and Photosystem I decreased, and Fo and non-photochemical parameters for PSII and PSI significantly increased due to Cd stress. This suggests that Cd affects the photochemistry efficiency at both the PSII and PSI levels. Nitric oxide supplementation through SNP ameliorated Cd stress by enhancing all the above mentioned parameters but causing a reduction in the Fo, and non-photochemical parameters of PSII and PSI in pea plants. These data indicate that the exogenous application of NO was useful in mitigating Cd-induced damage to photosynthesis in pea seedling.

Research Progress on the Land Application of Tannery Sludge

Tannery sludge are rich in organic matter and N, P, Fe, Mn, Cu, Zn and other nutrient elements and trace elements, at the same time, contain considerable amount of Cr and a small amount of Ni, Cd, Pb and other heavy metal elements. Land use is one of the effective ways to reduce the large amount of tannery sludge and reuse it. Based on the literature about land application of tannery sludge, the properties of tannery sludge and its influence on soil properties and soil plants after entering into the soil were summarized, as well as the risks of oxidation and migration of Cr, and soil salinization after the application of tannery sludge. Proper amount of tanning sludge can improve the physical properties of soil, for example, bulk density, porosity and water holding capacity, and increase the content of organic matter and N, P and K nutrient elements in soil, and stimulate the growth of microorganisms and enzyme activities in soil. How-ever, the application of tannery sludge can significantly increase the accumulation of Cr and salt in the soil, which has a negative impact on the physical and chemical properties of the soil, and there is a risk that Cr (III) will be transformed into Cr (VI) with stronger toxicity and migration ability, thus threatening the activities of microorganisms and plants. Based on the above analysis, the future research prospects were put forward in order to provide reference for the land use of tannery sludge.

Ion release and surface roughness of silver soldered bands with two different polishing methods: An in-vitro study.

OBJECTIVE:To evaluate the surface roughness and ion release of silver-soldered joints by using two polishing methods.METHODS:174 orthodontic bands with and without silver-soldered joints were evaluated and divided into three groups: two experimental, with different polishing methods (SP1 and SP2), and one control (SS) composed of bands without silver solder. For ionic release, 50 bands of each group were immersed in saline solution and submitted to atomic absorption spectrophotometry to quantify the amount of Fe, Ni, Cr (in all the three groups), Ag, Cu, Cd, and Zn (in the two experimental groups). A rugosimeter was employed to verify the surface roughness.RESULTS:Ni and Cr were released in higher amounts after soldering. Cd, Ag, Zn, and Cu may be released from silver-soldered bands independently of the polishing method employed. Ag was released in higher amounts from the soldered bands that presented higher surface roughness.CONCLUSIONS:Differences exist in relation to the surface roughness of silver-soldered bands when distinct polishing methods are used. Toxic ions may be released from silver soldered joints and higher surface roughness may cause higher ionic release.

Adsorption and desorption of Cu, Zn, Pb, and Cd on surface sediments from a shallow lake, North China

The processes of adsorption and desorption of heavy metal ions on sediments is of great significance for water quality conservation. To investigate the adsorption and release characteristics of heavy metals on sediments from shallow lakes, an isothermal adsorption and desorption experiment of Cu2+, Zn2+, Pb2+, and Cd2+ on sediments from Baiyun Lake was carried out. Our results showed that sediments demonstrated a strong capacity of absorbing these heavy metal ions in a sorption system. The maximum sorption capacity for heavy metals on sediments followed the order Pb2+> Cd2+> Cu2+> Zn2+. The followed order of the maximum buffer capacities for heavy metals was Pb2+ > Cu2+ > Zn2+ > Cd2+. The Langmuir isotherms model can better fit the adsorption of Cu2+, whereas the Freundlich isotherm model for the adsorption of Zn2+, Pb2+, and Cd2+. In the maximum initial concentration treatment, Pb exhibited the highest desorption amount, followed by Cu and Zn, whereas the lowest amount of Cd was observed. The exponential and quadratic functions could describe the relationships of adsorption and desorption. In the maximum initial concentration treatment, the adsorption rates of these four heavy metals followed the order Pb2+ > Cd2+> Cu2+> Zn2+, whereas the desorption rates followed an opposite order. The hysteresis index (HI) values for Zn was smaller than 1, whereas the HI values for Cu and Cd were slightly larger than 1, suggesting slightly negative hysteresis processes. However, the HI value of Pb was larger than 1, indicating that Pb2+ was easily desorbed from sediments.

Adsorption Performance of Two Kinds of Biochar for Cd<sup>2+</sup> in Water

Cadmium is one of the most widely distributed and toxic pollutants in nature, and the remediation of Cd pollution is still a difficult and serious task. In this paper, the biochar derived from walnut shells and sunflower seed shells were prepared at 700°C. The two kinds of biochar were characterized by SEM and FTIR, and the effects of pH, adsorption time, initial concentration on the adsorption of Cd²⁺ in aqueous solution were investigated. The adsorption kinetics were studied and the experimental data was also fitted with the isotherm equilibrium models. The results showed that the adsorption amount of Cd²⁺ increased with the pH when the solution pH was between 2 and 7. The maximum adsorption amount of Cd in water was up to 12.94 mg•g^-1 and 21.11 mg•g^-1 for BWS and BSS. The adsorption kinetics of Cd²⁺ on the BWS and BSS followed pseudo-second-order kinetics. The Langmuir adsorption isotherm was used to describe the adsorption equilibrium process isotherms. Thermodynamic studies showed that the adsorption reaction was spontaneous, endothermic and entropy increasing. The analysis of microstructural characteristics indicated that complexation and ion exchange are the main mechanisms of cadmium adsorption on the two kinds of biochar. And the surface of the BSS contained a large number of functional groups. Compared with the BSS exhibited better Cd²⁺ adsorption capacity. The results of this research are important for the resourceful use of waste and the purification of heavy metals in water.

Integrative analysis of transcriptome and proteome provides insights into adaptation to cadmium stress in Sedum plumbizincicola

Sedum plumbizincicola, a cadmium (Cd) hyperaccumulating herbaceous plant, can accumulate large amounts of Cd in the above-ground tissues without being poisoned. However, the molecular mechanisms regulating the processes are not fully understood. In this study, Transcriptional and proteomic analyses were integrated to investigate the response of S. plumbizincicola plants to Cd stress and to identify key pathways that are potentially responsible for Cd tolerance and accumulation. A total of 630 DAPs (differentially abundant proteins, using fold change >1.5 and adjusted p-value <0.05) were identified from Tandem Mass Tag (TMT)- based quantitative proteomic profiling, which were enriched in processes including phenylpropanoid biosynthesis, protein processing in endoplasmic reticulum, and biosynthesis of secondary metabolites. Combined with the previous transcriptomic study, 209 genes and their corresponding proteins showed the identical expression pattern. The identified genes/proteins revealed the potential roles of several metabolism pathways, including phenylpropanoid biosynthesis, oxidative phosphorylation, phagosome, and glutathione metabolism, in mediating Cd tolerance and accumulation. Lignin staining and Cd accumulation assay of the transgenic lines over-expressing a selected Cd up-regulated gene SpFAOMT (Flavonoid 3′,5′-methyltransferase) showed its functions in adapting to Cd stress, and provided insight into its role in lignin biosynthesis and Cd accumulation in S. plumbizincicola during Cd stress.

Genotoxicity of PM2.5 and PM1.0 Particulates on Human Peripheral Blood Lymphocytes in Manila, Philippines

Urban air quality is increasingly being studied as a fraction of the world’s population is living in megacities. In this study, particulate matter (PM) along Taft Avenue, Manila, the Philippines, is investigated in terms of its ability to induce genetic damage in human peripheral blood lymphocytes (PBLs). Size-segregated roadside air samples were obtained from 2015–2017 near a university gate and analyzed using in vitro micronucleus (MN) and cytokinesis-block proliferation tests. While cellular proliferation was unaffected by 0–0.1 kg/m3 of PM1.0 and PM2.5, PBL cells treated with PM2.5 displayed a significantly higher micronucleus count (p = 0.03) compared to the cells treated with PM1.0. Atomic absorption spectroscopy revealed greater amounts of Cd, Ca, Pb, K, Na, and Zn in PM2.5 compared to PM1.0. The results indicate that the differences in composition of the two size fractions of air particulates are associated with their genotoxicities.

Lead and other elements-based pollution in soil, crops and water near a lead-acid battery recycling factory in Bangladesh

Lead (Pb) pollution in the environment predominantly occurs through anthropogenic activities, which pose significant threats to human health and that of biota. In this study, Pb and other elements were investigated in different soils (n = 52), crops (n = 24) and water (n = 13) around a lead-acid battery (LAB) recycling workshop in southwestern Bangladesh. Most of the elements’ concentrations (except Se and Ag) in soil were lower than the background concentrations. However, excessive concentrations of Pb were found in both surface (966 ± 2414 mg kg−1 at 0–15 cm) and subsurface (230 ± 490 mg kg−1 at 15–30 cm) soil. Although no definitive pattern or direction in elemental concentration in soil was observed, relatively higher concentrations of most elements were detected at the southeast part of the factory. The LAB factory, brick kiln, agricultural and geogenic activities might be the sources of these elements in soil. Extremely high amounts of Cr, As, Cd, and Pb were found in the food crops around the area. In particular, the Pb concentrations were 114 ± 155 and 665 ± 588 mg kg −1 dry weight in rice grain and straw, respectively, which reflected the emissions of Pb from the LAB recycling workshop. Moreover, 40% and 100% of the groundwater samples exceeded, respectively, the WHO provisional guideline values for As (0.01 mg L−1) and Pb (0.05 mg L−1). Consequently, a high level of Pb contamination in the soil was observed while assessing different soil pollution indices. Human health risk assessment indicated severe carcinogenic (from Pb, As, and Cr intake) and non-carcinogenic (from Pb, As, Co, Cr, Ni and Sb intake) health risks are associated with rice and groundwater consumption. It is concluded that all LAB recycling workshops should be better managed to prevent Pb pollution from seeping into the environment.

Amendments and bioaugmentation enhanced phytoremediation and micro-ecology for PAHs and heavy metals co-contaminated soils

Co-existence of polycyclic aromatic hydrocarbons (PAHs) and multi-metals challenges the decontamination of large-scale contaminated sites. This study aims to comprehensively evaluate the remediation potential of intensified phytoremediation in coping with complex co-contaminated soils. Results showed that the removal of PAHs and heavy metals is time-dependent, pollution-relevant, and plant-specific. Removal of sixteen PAHs by Medicago sativa L. (37.3%) was significantly higher than that of Solanum nigrum L. (20.7%) after 30 days. S. nigrum L. removed higher amounts of Cd than Zn and Pb, while M. sativa L. uptake more Zn. Nevertheless, amendments and microbial agents significantly increased the phytoremediation efficiency of pollutants and shortened the gap between plants. Cd removal and PAHs dissipation reached up to 80% and 90% after 90 days for both plants. Heavy metal stability in soil was promoted after the intensified phytoremediation. Plant lipid peroxidation was alleviated, regulated by changed antioxidant defense systems (superoxide dismutase, peroxidase, catalase). Soil enzyme activities including dehydrogenase, urease, and catalase increased up to 5-fold. Soil bacterial diversity and structure were changed, being largely composed of Proteobacteria, Actinobacteria, Patescibacteria, Bacteroidetes, and Firmicutes. These findings provide a green and sustainable approach to decontaminating complex-polluted environments with comprehensive improvement of soil health.

Study on the occurrence of typical heavy metals in drinking water and corrosion scales in a large community in northern China

Excessive heavy metal content in drinking water could lead to red water and acute and chronic diseases. A field study in combination with batch experiments using pipe scales of drinking water distribution systems (DWDS) in the study area, was used to determine the content distribution and migration of As, Cd, Cr, Mn, Pb, and V in DWDS. In the field study, As, Cd, Cr, Pb, and V contents in pipe scales and drinking water were extremely low and did not exceed the Chinese drinking water standards. However, Mn concentrations at the end of the DWDS with aged and corrosive pipes were relatively high, which presented a risk of excessive release. The batch experiment showed that As in pipe scales would not be released into water under static immersion conditions; however, pipe scales would release excessive Cd, Cr, Mn, Pb, and V in the initial reaction stage, and the heavy metal contents released by tubercle scales in the initial release stage were at least twice as much as those released by loose scales. The mass percentage of four metals (excluding Cd and Pb) released from pipe scales was extremely low. The field study and batch experiment data both suggested a strong correlation between Cr and V released into the water, indicating a synergistic effect. There were differences in heavy metals released in the field research and the batch experiment. The amount of Cd, Cr, Pb, and V released were not consistent with its proportion in pipe scales. As release did not occur under static conditions, but may be promoted by the water flow in the actual network. The effect of water flow on heavy metal release in DWDS should be considered.

Phytoremediation in Removing Selected Heavy Metals from Aqueous Solutions

Bioaccumulation of Ulothrix zonate was compared for cadmium, copper, nickel, and zinc removal at various concentrations and contact time. The results of the present investigation showed that the lowest amount of Cd, Cu, Ni and Zn was adsorbed when the initial heavy metal concentration was 10 ppm whereas Cd showed highest concentration at 20 ppm and Cu exhibited greatest removal at 30 ppm. The metals Ni and Zn exhibited highest removal at 40 ppm. The value of Freundlich model constant (1/n) for different metals ranged from 0.334 to 0.721 and the values of Langmuir separation factor values (RL) varied between 0.111 and 0.722 which indicated favorable bio-sorption by the biomass of the algae. The order of metals uptake was found to be Ni&gt;Zn&gt;Cu&gt;Cd. The finding of the study showed that U. zonate has much potential as a biosorbent for the sorption of Cd, Cu, Ni and Zn and indicated that the metal uptake was concentration-independent for Cd and Zn whereas for Cu and Ni an increase in initial metal concentration resulted in higher metal uptake. This present study leads the way for the future studies on the use of algae as a cheap bio-adsorbent for heavy metals removal in Iraq which is suffering from huge inland waste water.

Preparation and Characterization of Indomethacin Supramolecular Systems with β-Cyclodextrin in Order to Estimate Photostability Improvement.

Cyclodextrins have found wide application in contemporary chemistry, pharmacy and medicine. Because of their unique properties, cyclodextrins are constantly used in research on solubility or stability improvement, as well as other physicochemical properties of medicinal substances. Indomethacin (IND) is a photolabile molecule that also attracts the interest of researchers due to its therapeutic potential and the need to overcome its problematic photosensitivity. Supramolecular complexes of indomethacin with β-cyclodextrin (CD) are already known, and they show greater stability compared to complexes with other types of cyclodextrins. So far, however, the sensitivity to light of physical mixtures and inclusion complexes in the solid phase has not been studied, and their various stoichiometries have not yet been investigated. Due to this fact, the aim of the present study is to obtain supramolecular systems (inclusion complexes and physical mixtures) of indomethacin with three different amounts of β-cyclodextrin. Assessment of the photochemical stability of indomethacin-β-cyclodextrin systems in the solid state is performed in order to find the best correlation between IND stability and the amount of CD. Comparative analysis of physicochemical degradation for stoichiometry systems [CD:IND] = [1:1], [0.5:1] and [0.1:1] is performed by using ultraviolet spectroscopy, transmission—FTIR, reflection—ATR-FTIR infrared spectroscopy and DSC calorimetry.

Trophic Transfer without Biomagnification of Cadmium in a Soybean-Dodder Parasitic System.

Cadmium (Cd) is among the most available and most toxic heavy metals taken up by plants from soil. Compared to the classic plant-animal food chains, the host-parasitic plant food chains have, thus far, been largely overlooked in the studies of Cd trophic transfer. To investigate the pattern of Cd transfer during the infection of parasitic plants on Cd-contaminated hosts, we conducted a controlled experiment that grew soybeans parasitized by Chinese dodders (Cuscuta chinensis) in soil with different levels of Cd treatment, and examined the concentration, accumulation, allocation and transfer coefficients of Cd within this parasitic system. Results showed that among all components, dodders accounted for more than 40% biomass of the whole system but had the lowest Cd concentration and accumulated the least amount of Cd. The transfer coefficient of Cd between soybean stems and dodders was much lower than 1, and was also significantly lower than that between soybean stems and soybean leaves. All these features were continuously strengthened with the increase of Cd treatment levels. The results suggested no evidence of Cd biomagnification in dodders parasitizing Cd-contaminated hosts, and implied that the Cd transfer from hosts to dodders may be a selective process.

Evaluation of Cadmium Bioaccumulation-Related Physiological Effects in Salvinia biloba: An Insight towards Its Use as Pollutant Bioindicator in Water Reservoirs

Free-living macrophytes play an important role in the health of aquatic ecosystems. Therefore, the use of aquatic plants as metal biomonitors may be a suitable tool for the management of freshwater reservoirs. Hence, in this study, we assessed the effects of cadmium (Cd) in Salvinia biloba specimens collected from the Middle Paraná River during a 10-day experiment employing artificially contaminated water (100 μM Cd). S. biloba demonstrated a great ability for Cd bioaccumulation in both the root-like modified fronds (named “roots”) and the aerial leaf-like fronds (named “leaves”) of the plants. Additionally, Cd toxicity was determined by the quantification of photosynthetic pigments (chlorophylls a and b, and carotenoids), flavonoids, and soluble carbohydrate contents in S. biloba over time (1, 3, 5, 7, and 10 days). In general, deterioration was more pronounced in leaves than in roots, suggesting a greater implication of the former in long-term Cd sequestration in S. biloba. Deleterious effects in the appraised parameters were well correlated with the total amount of Cd accumulated in the leaves, and with the qualitative changes observed in the plants’ phenotype during the 10-day metal exposure assay. The flavonoids and carotenoids in leaves were highly affected by low Cd levels followed by root carbohydrates. In contrast, chlorophylls and root flavonoids were the least impacted physiological parameters. Therefore, our results demonstrate that S. biloba displays dissimilar organ-linked physiological responses to counteract Cd phytotoxicity and that these responses are also time-dependent. Though further research is needed, our work suggests that easy-handled physiological data obtained from autochthonous free-floating S. biloba specimens may be used as a valuable tool for metal-polluted water biomonitoring.

Optimizing Room-Temperature Thermoelectric Performance of n-Type Bi2Te2.7Se0.3.

Bi2Te3-based compounds are exclusive commercial thermoelectric materials around room temperature. For n-type compounds, optimal thermoelectric properties are normally obtained at temperatures higher than room temperature to suppress the bipolar effect through increased carrier concentration. We find that doping with trace amounts of Cd and the addition of excess Bi are effective ways to optimize carrier concentration and achieve enhanced room-temperature thermoelectric performance for the Bi2Te2.7Se0.3 alloy in this work. For the Cd-doped samples, the replacement of Cd with Bi leads to not only a significant decrease in electron concentration but also apparently reduces the total thermal conductivity. The addition of excess Bi in the samples creates a Bi-rich synthetic atmosphere during the synthesis process, leading to increased BiTe antisite defects, decreased electron concentration, and reduced total thermal conductivity. Doping a small amount of Cd or adding excess Bi causes optimal thermoelectric performance of the n-type Bi2Te2.7Se0.3 sample shifts obviously toward low temperatures, and the samples with 0.4 atom % Cd and 0.8 atom % excess Bi achieve maximum zT of ∼0.97 at 448 K and ∼0.88 at 348 K, respectively.

Pollution zoning on the southern shores of the Caspian Sea by measuring metals in Rutilus kutum tissue.

The aim of this study was to bio monitor the status of heavy metals on the southern shores of the Caspian Sea by determining the concentration of these metals in the tissue of Rutilus kutum. Sampling of kidney tissue, liver, muscle, skin, and gonad of this fish was performed in 5 sites. Sampling was performed in Anzali, Kiashahr, Astara, Farahabad, and Bandar Torkaman from September 2017 to January 2018. In this study, the concentration of elements in different tissues was determined. Contamination zonation was determined by the concentration of metals in fish tissues. The highest amount of Pb accumulation (0.73ppb) was determined in Astara and Anzali regions and in liver tissue. The highest amount of Cd (0.23ppb) was reported in Astara region and in fish liver. Zoning showed that the concentration of most elements in the west of the Caspian Sea is higher than in the east; in other words, the west of the Caspian Sea is more polluted than the east. Existence of polluting sources such as ports, customs, agricultural lands, and tourism industry are important factors of pollution in these areas. Annual biological monitoring along with accurate identification of pollutant sources can help reduce this pollution, especially in the western part of the Caspian Sea. This study showed that the use of zoning technique in environmental studies as an effective management tool can be very useful in providing appropriate ways to identify and control sources and pollutants in the coast.

Cadmium and Lead Content in Selected Fungi from Poland and Their Edible Safety Assessment.

Mushrooms are able to accumulate toxic trace elements. This study investigates the content of cadmium (Cd) and lead (Pb) in selected species of fungi (Boletus badius, Boletus edulis, and Cantharellus cibarius) from the northeastern part of Poland and estimates their edible safety. The amount of Cd and Pb was determined by flameless atomic spectrometry using the iCE 3000 Series-Thermo. The mean content of Cd in analyzed mushrooms ranged from 0.370 to 2.151 mg/kg d.w., while Pb was found at the level of 0.243–0.424 mg/kg d.w. Boletus edulis was characterized by the highest content of Cd, whereas Cantharellus cibarius contained the biggest amount of Pb. Estimated exposure to the Cd intake expressed as percentage share in TWI (Tolerable Weekly Intake) was at the highest level in Boletus edulis (30.87%), which could be associated with the risk of excessive Cd accumulation in the body.