Lead Salts Research Articles

Increasing the resistance of barley sprouts by priming with heavy metal salts

The article investigated the different concentrations of cadmium and lead salts influence to the growth and development of barley plant shoots. As a response of sprouts to the action of lead and cadmium ions, changes in the accumulation of their wet and dry biomass, the height of the sprouts, as well as survival were evaluated. Since CdCl2 and Pb(CH3COO)2 belong to the group of heavy metals with a strong toxic effect, when they are individually administered, there is a decrease in the growth of shoots and a slowdown in development due to the accumulation of wet and dry biomass of the plant. While inhibition of sprouts at a concentration of Pb(CH3COO)2 0.5-10 mM reduced sprouts by 2-10 times, the effect of CdCl2 on barley sprouts in high concentrations led to a halt in the accumulation of dry mass. Processing of barley sprouts before sowing with a low concentration of lead and cadmium salts increases their resistance to metals and allows in the future to transport the effects of high concentrations of these substances without damage and with minimal inhibition of growth processes. In addition, these metals are powerful inducers of phytochelatin synthesis. Thus, the accumulation of osmoprotectants is unlikely to play an important role in cell detoxification from heavy metals. Apparently, the possible role of the accumulation of osmoprotectants in the presence of heavy metals is not necessarily associated with metal chelation. First, heavy metals usually disrupt the water balance in the cell. It is known that water deficiency always leads to the accumulation of osmoprotectants in the plant cell. The accumulation function of osmoprotectants caused by heavy metals may be more associated with osmoregulation and enzyme protection against dehydration than with direct metal chelation. Keywords: the growth and development of barley sprouts, lead and cadmium salts, priming, stability.

Effect of various types of anions and anionic surfactants on the performance of micellar-enhanced ultrafiltration process in the removal of Pb(II) ions: An optimization with the response surface methodology

In the present study, the micellar-enhanced ultrafiltration (MEUF) process was employed for the removal of Pb2+ ions from aqueous solutions using sodium dodecyl sulfate (SDS) and sodium lauroyl sarcosinate (Sarkosyl) as the anionic surfactants. The performance of Sarkosyl was compared to SDS, a frequently used surfactant in the MEUF processes, to evaluate their efficiency in the removal of lead ions. Sodium chloride (NaCl) was used as the electrolyte and the role of lead salt anions, lead nitrate (Pb(NO3)2) and lead chloride (PbCl2), was also investigated for the first time in the MEUF process. The MEUF process was modeled using response surface methodology (RSM), and experiments were designed and carried out based on the central composite design (CCD). Two categorical variables of anionic surfactants and lead salts, and two numerical variables of Pb2+ and electrolyte concentrations were considered as the studied factors in this design. The process was assessed in terms of its ability to simultaneously maximize Pb2+ rejection and permeate flux. The results showed that increasing the concentration of NaCl significantly reduces the permeate flux, while lead ions concentration has a negligible impact on the permeate flux. The response surface plots also indicated that the effect of the anionic surfactant type on the permeate flux is insignificant. In the studied range of lead concentrations, the highest removals of Pb2+ ions were observed at the concentration of 21 mg/L of Pb(NO3)2 and 0.05 M of NaCl, equal to 79.27% and 94.74% for Sarkosyl and SDS anionic surfactants, respectively.

Revealing M (M = Cu, Co and Zr) oxides doping effects on anti-PbCl2 poisoning over Mn-Ce/AC catalysts in low-temperature NH3-SCR reaction

Lead salts poisoning was a great challenge for the catalysts application in selective catalytic reduction (SCR) reaction of NOx with NH3 in stationary sources. Herein, several typical transition metal (Cu, Co and Zr) oxides modified Mn-Ce/AC catalysts were prepared by impregnation method, and the effects of Cu, Co and Zr doping on resistance PbCl2 poisoning for the catalyst were investigated. The addition of three transition metal oxides improved the PbCl2 resistance of Mn-Ce/AC catalyst and maintained excellent low-temperature denitrification activity of the catalyst. The lead resistance performance of the three metal oxides followed: Cu > Co > Zr oxides. The NO conversion of Cu-doping catalyst after PbCl2 poisoning was only ca. 10% lower than that of fresh Mn-Ce/AC catalyst at 225 °C. Cu, Co and Zr doping could decrease the loss of specific surface area caused by poisoning, while Cu-doped catalyst showed lowest crystallinity of active components. Meanwhile, the contents of Mn4+ and chemisorbed oxygen in Cu-doped catalyst were higher than those in Co- or Zr-doped catalysts. Cu, Co and Zr doping improved the surface acidity and redox performance of the poisoned catalysts, with Cu-doped poisoned catalyst exhibiting nearly the same surface acidity and redox performance as the fresh Mn-Ce/AC catalyst. Furthermore, Cu doping could also improve NO adsorption and was in favor to the SCR process. Besides, in situ DRIFTS results showed that the catalytic reaction pathways of all the poisoned or modified catalysts were in accordance with both Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) mechanisms. Finally, a possible anti-PbCl2 poisoning mechanistic model of (Cu, Co and Zr) oxides modified on Mn-Ce/AC catalyst was proposed.

The effects of heavy metals on the developing brain

The analysis shows that there are disproportionately few works on the mentioned joint effects of HMs in relation to the importance of this issue. It was found that the joint administration of HMs with each other and under stress increases the neurotoxic effect of metals on the brain of animals. A greater vulnerability to the neurotoxic effects of HM mixtures on the developing brain was also noted. Neurotropic drugs in combination with HMs have multidirectional effects. Thus, along with the counteraction of the reference nootropic piracetam to the inhibition of the avoidance response in rats, which is exerted by HMs, there was an increase in the neurotoxic effects of lead and cadmium salts when combined with that nootropic. Combined administration of Semax (a regulatory peptide with nootropic effects) and molybdenum, which separately suppressed the avoidance response in rats, paradoxically improved learning and memory. The revealed unpredictability and enhancement of the neurotoxic effects of HMs when combined with neurotropic agents are fraught with danger to human health in regions with developed industries. This is especially important for the health of children due to the increased vulnerability of their developing brains to neurotoxicants.

Effects of Heavy Metals on Bacterial Growth, Biochemical Properties and Antimicrobial Susceptibility

Heavy metals are metallic elements that occur naturally and have a high atomic weight and a density which is five times greater than the density of water. Several studies have demonstrated that metal contamination in natural environments could have an important role in the development and spread of antimicrobial resistance. This is of particular concern, considering that heavy metals usually occur at higher levels than pharmaceutically produced antimicrobials. Also, the bio-accumulative and non-biodegradable nature of heavy metals may result in long- term antimicrobial resistance selection pressure. Therefore, this study assessed the effects of Copper, Cobalt, Cadmium, Zinc and Lead salts on growth, biochemical properties and antimicrobial susceptibility of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus to commonly used antimicrobials. The selected bacteria were exposed to varying concentrations of the heavy metal salts ranging from 1 ppm to 1000 ppm after which growth was measured using a spectrophotometer. The effect on biochemical reactions and antimicrobial susceptibility were also tested by the use of conventional biochemical tests and Kirby-Bauer disk diffusion methods respectively. Different heavy metals affected the growth of each individual microorganism differently. Despite that, the growth of E. coli, P. aeruginosa and S. aureus was observed to be inversely proportional to the concentrations of the heavy metals used. Following exposure to heavy metals, E. coli and S. aureus showed no changes in their biochemical properties but P. aeruginosa gave a positive urease result contrary to the control. E. coli developed resistance to Levofloxacin, Meropenem and Tetracycline while S. aureus to Azithromycin and Gentamicin and P. aeruginosa developed resistance only to Meropenem. These results confirm the adverse effects of heavy metals on bacterial growth and reveals that heavy metals can cause changes in some biochemical properties of bacteria that produce any of these properties under stressful growing conditions. This research also supports the findings that heavy metals enhance the development of antimicrobial resistance in otherwise antimicrobial sensitive strains of bacteria. This study therefore, gives insight into the likely state of the proliferation of heavy metal induced antimicrobial resistance in heavy metal contaminated areas.

Different lead species deactivation on Mn-Ce activated carbon supported catalyst for low-temperature SCR of NO with NH3: Comparison of PbCl2, Pb (NO3)2 and PbSO4

Due to the accumulation of heavy metal compounds produced by the sintering process in steel industry, the catalysts used for low-temperature selective catalytic reduction of NO with NH3 (NH3-SCR) might be seriously deactivated. In this work, the deactivation effect of PbCl2, Pb(NO3)2, and PbSO4 on Mn-Ce activated carbon supported catalyst for low-temperature NH3-SCR of NO was investigated and compared. Poisoned catalysts were provided by impregnating fresh catalysts with Pb(NO3)2, PbSO4 and PbCl2 aqueous solutions, respectively. Deactivation could be observed on the poisoned samples, and the deactivation degree was following PbCl2 > PbSO4 > Pb(NO3)2. The catalytic activities of all samples were tested, and the physicochemical properties of fresh and poisoned catalysts were assessed. PbCl2 caused the most severe deactivation of the catalyst, owing to its poor redox property and surface acidity. Cl- could also react with Mn active sites to form -O-Mn-Cl bonds, resulting in additional acid sites, although these newly generated sites were not reactive in NH3-SCR reaction process. PbSO4 exhibited moderate poisoning effect due to the addition of SO42-, which created new Brønsted acid sites, facilitating the NH3 adsorption and NO reduction. Pb(NO3)2 had the least poisoning impact on the catalyst due to the NO3–, promoting the NH3 activation. The in situ DRIFTS results revealed that NH3-SCR reaction over all samples was governed by Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanism, and did not change due to the lead poisoning. Finally, a possible mechanistic model for different lead salts poisoning over Mn-Ce/AC catalyst was proposed.

-Ferrocenedicarboxylic Acid Salts as Burning Rate Modifiers of Double-Base Propellant

To expand the possibilities of using solid propellants in gas generators or civil- purpose rockets, the properties of new compounds proposed as burning rate modifiers were considered. -ferrocenedicarboxylic acid and its insolubility in water copper, iron, and lead salts were synthesized. The effect of the salts on the burning rate of a double-base propellant was studied. It was shown that individually 3% of copper salt (CFDA) has the most considerable effect on the burning rate, increasing by times at the pressure interval of 1–10 MPa. It is possible to lower the n value in the burning law from 0.71 to 0.21 in a pressure range of 6–15 MPa with use of lead salt. Carbon nanotubes significantly increase the efficiency of FDA salts. An interesting phenomenon was discovered: Iron salt (IFDA) affects the burning rate only at pressure up to 2 MPa, and at higher pressures, but only in combination with a carbon nanotube. IFDA also reduces the efficiency of CFDA. An explanation of that fact was suggested.

A universal ionic liquid solvent for non-halide lead sources in perovskite solar cells

Replacing lead iodide (PbI2) with suitable non-halides lead source has been found to be an effective method to control crystallization and fabricate high-performance perovskite solar cells (PSCs). However, the solubility of non-halide lead sources is highly limited by traditional solvents due to the chemical interaction limitation. Here, we report a series of non-halide lead sources (e.g., lead acetate (PbAc2), lead sulfate (PbSO4), lead carbonate (PbCO3), lead nitrate (Pb(NO3)2), lead formate (Pb(HCOO)2) and lead oxalate (PbC2O4)) can be well dissolved in an ionic liquid solvent methylammonium acetate (MAAc). We found that the universal strong coordination of CO with lead ion (Pb2+) and the formation of hydrogen bonds were observed in perovskite precursor solution. This allows the dissolution of non-halide lead salts and is able to produce perovskite film with smooth, compact, and full coverage crystal grain. The power conversion efficiency (PCE) of 14.48%, 19.21%, and 20.13% in PSCs based on PbSO4, PbAc2, and PbCO3 was achieved, respectively, in the absence of any additives and passivation agents. This study demonstrates the universality of ionic liquid for the preparation of PSCs based on non-halides lead sources.

Hot-carrier infrared detection in PbS with ultrafast and highly sensitive responses

Traditional infrared semiconductors with direct narrow bandgaps, such as HgCdTe, InGaAs, and lead salts (PbS, PbSe, and PbTe), have been commercialized for decades in various infrared technologies, such as night vision, military communication, and health monitoring. However, traditional infrared (specifically middle- and long-wave infrared) semiconductors suffer from serious noise generation via thermal excitation and external current bias. Although thermal infrared detectors can operate at room temperature, their response speed is very slow, typically on the order of milliseconds or worse, which limits their applications. Herein, we reinvent a classical lead salt semiconductor (PbS) as a room temperature, high speed, and high-detectivity infrared detector. The detection is operated via the self-driven (no bias voltage necessary) photothermoelectric (PTE) effect with a response time reaching 500 ns (limited by the measurement setup)—three orders of magnitude faster than commercial PTE and photoconductive PbS detectors. Furthermore, the physical principle of hot-carrier-dominated heat energy conversion is proposed to understand the unconventional ultrafast response behavior. Combined with high sensitivity at room temperature (noise equivalent power 0.3 pW Hz−1/2) and broadband detection range (0.4–2.3 μm), this hot carrier makes the traditional commercial semiconductor PbS applicable to a class of infrared detection applications.

The Negative Effect of Heavy Metal Salts on the Body of Mammal Animals

The main purpose of this presented article was to explain the need to study the amount of heavy metal salts in the environment where animals live, in the water, in air, and in the food and fodder consumed. This article presents materials from the literature on the effects of heavy metal salts on the body of animals and the environment in which they live. The cited analytical data showed that the general information on the negative effects of heavy metal salts on the body is sufficient, but their effects on the digestive tract and morpho-functional properties of rabbits should be studied in depth. Therefore, we planned to focus our scientific work on this topic. The article mainly refers to salts of heavy metals cadmium, lead, and mercury (Cd, Pb, Hg). It is noted in the literature that heavy metal salts have a negative effect on the body of animals. We focused mainly on data on the effects of heavy metals on farm animals, including rabbits. But it is clear that the authors referred to were referring to experimental animals. These negative effects are manifested in the form of disorders of digestive functions, disorders of neurovegetative processes, increasing incidence of cardiovascular disease, rapid heart failure, deterioration of calcium metabolism, as well as impaired haemoglobin metabolism. Disorders of protein metabolism manifest themselves in the form of cases of hyperproteinaemia and dysproteinaemia. The results of the evaluation of the organism of healthy animals in chemically and radioactively contaminated areas showed the accumulation of significant levels of chemical elements in their organism. We mainly looked at the effects of heavy metal salts on farm animals. The cited analytical data showed that the general information on the negative effects of heavy metal salts on the body is sufficient, but the effects on the activity of organ systems in the body (respiration, blood and blood circulation, digestion, reproduction, productivity and immunological systems) have not been comprehensively studied.

Manage the environmental risks of perovskites

Manage the environmental risks of perovskites

Evaluating the xerophilic potential of moulds on selected egg tempera paints on glass and wooden supports using fluorescent microscopy

• 11 fungal isolates from cultural heritage institutions’ interiors were screened for xerophilic trait. • Specially designed incubators were constructed to hold specific RH levels of 55%, 63% and 74.% • Fungal growth was monitored at low relative humidity on wood and glass supports painted by traditional artists’ paints. • Effects of pigments, support materials and strain variability are discussed. Even though contamination of painted artwork by xerophilic moulds frequently causes aesthetical, physical and/or biochemical biodeterioration, mould growth on paints, prepared from assorted traditional artists’ pigments, has yet to be systematically evaluated especially with regard to low relative humidity (RH) levels and painted support materials. Therefore, we investigated 11 fungal strains isolated mostly from cultural heritage institutions’ interiors for their potential to grow on egg tempera paint films prepared with different colouring agents and applied on wooden and glass supports which were maintained in monoculture in specially designed incubators at three different RH levels of 55%, 63% and 74%. The growth rate of mould over the surface was assessed using fluorescent microscopy after Calcofluor White staining. Additionally, these stains were screened for their xerophilic and hydrolytic potential using standard microbiological assays. Results show that when comparing growth rates on egg tempera paint films, 6 isolates grew exclusively on wood, exemplifying the greater susceptibility of this supporting material to mould attack. Prussian blue paint also stimulated the growth of 6 isolates, and the maximum overall expansion (38%) was observed on Prussian blue painted wood. RH was the key factor limiting growth, and at RH of 55% only a slight growth of 2 isolates was observed on Prussian blue painted wood. On the same samples incubated at RH of 63%, 10 isolates exhibited a moderate to strong growth and 4 of these showed an additional increase in growth at 74% RH. Paints consisting of artists’ pigments carmine lake or lead white in general completely prevented the development of moulds. Nevertheless, tolerance was species/strain dependant and the growths of isolates Cladosporium halotolerans EXF-15,333, Aspergillus niger EXF-14,897 and Aspergillus creber EXF-15,148 on lead white paint (containing ions and salts of heavy metal lead (Pb +2 )) even exceeds 11%. Standard microbiological tests showed that all stains had hydrolytic potential and proved positive for xerophilic trait, nevertheless their ability to develop on egg tempera paint films was mostly dependant of very specific conditions.

STRUCTURAL AND FUNCTIONAL CHANGES IN TONGUE TISSUES UNDER PER OS ADMINISTRATION OF HIGH DOSES OF LEAD ACETATE

The main purpose of this study was to evaluate the structural transformation in rats’ tongue tissue after oral administration of lead salts. Under the conditions of acute experiment during 5 days Wistar rats were orally administered the lead acetate solution in the amount of 24 mg per day. Histological studies were carried out at OSMU upon the completion of the experiment. Effect of toxic doses of lead results in symptoms of both hyperkeratosis and destruction of tongue tissue. It is assumed that the oxidative stress and tissue irritation, induced by lead intoxication, causes pathological changes in the shape, height and number of filiform papillae of the tongue. This results in hyperkeratosis, hydropic degradation of the epithelium and in the presence of an inflammatory infiltrate in the connective tissue.

Assessment of the resistance of highly ornamental plants of autochthonous flora to increased concentrations of pollutants

Aim. The purpose of the work is to assess the resistance of highly decorative plants of the native flora to a high level of salinity and the content of zinc, lead and cadmium for landscaping urban and roadside areas. Methods. We used seed germination under laboratory conditions with soaking in solutions of sodium chloride and salts of zinc, lead and cadmium, as well as the method of in vitro cell selection to increase resistance to salinity of Verbascum nigrum L. Results. The resistance of 7 species of highly decorative plants, representatives of the autochthonous flora of Belarus, to increasing concentrations of lead, zinc and cadmium salts was assessed. Germination capacity, length and morphology of roots, length of seedlings during germination of seeds of Betonica officinalis L., Centaurea jacea L., Verbascum nigrum, Knautia arvensis (L.) Coult., Galium verum L., Anthemis tinctoria L., Anthemis arvensis L., Viscaria vulgaris Bernh., Achillea millefolium L. in the presence of sodium chloride are shown. It has been shown that the in vitro cell selection method is promising for the selection of resistant lines of Verbascum nigrum. Conclusions. The presence of lead, zinc and cadmium salts had a significant effect on the average length of the root, hypocotyl, and cotyledonous leaves, as well as the germination capacity of highly decorative species of autochthonous flora. The most resistant to salinity were yarrow (Achillea millefolium), brown knapweed (Centaurea jacea) and black mullein (Verbascum nigrum). Lines of Verbascum nigrum, capable of growing in vitro at a sodium chloride concentration of 5 g/L, were selected. Keywords: salinity, heavy metals, seed germination, highly decorative species.

Rejection of antimony and bismuth in sulphide flotation – a literature review

ABSTRACT Rejection of deleterious impurity minerals containing antimony and bismuth from sulphide deposits by flotation has been reviewed. The key antimony minerals of commercial interest to remove are stibnite, tetrahedrite, and jamesonite, while the main bismuth mineral is bismuthinite. The most promising methods for separating antimony and bismuth minerals from sulphide ores are based on pH and/or pulp potential adjustments or the use of starvation levels of collector. Stibnite has been floated with xanthate, dithiophosphates and thionocarbamates in acidic conditions, but floatability decreased with increasing pH. Antimony minerals are activated with lead and copper salts and depressed with an oxidant (e.g. H2O2 or Na2Cr2O7). Bismuth minerals can float strongly between pH 3 and 7 with a xanthate collector but floatability decreased sharply at pH values above pH 7. Molybdenite is separated from bismuth minerals by depressing them with reducing agents such as sodium sulphide, while cyanide depresses chalcopyrite.

Efficient Concentration of PB From Water by Reactions With Layered Alkali Silicates, Magadiite and Octosilicate

AbstractHuman health problems are often related to contamination of the aqueous environment by toxic metal ions. In the present study, two layered alkali silicates (magadiite and octosilicate) were examined to assess removal of Pb2+ from aqueous solutions in terms of quantity and kinetics. The ion-exchange reaction between the silicates and aqueous solutions of lead(II) acetate at various concentrations was examined at room temperature for 24 h. The adsorption isotherms were H-type, showing the strong interactions between Pb2+ and the silicates. The amounts of Pb2+ adsorbed were as much as 1.23 mmol Pb/g magadiite and 2.32 mmol Pb/g octosilicate, which are larger than the reported values for various ion exchangers. They were larger than the theoretical cation exchange capacities (2.2 and 3.7 meq/g for magadiite and octosilicate, respectively), suggesting that the collection of Pb2+ included the precipitation as basic lead salts in addition to the ion exchange. The adsorption isotherms for magadiite and octosilicate fitted the Langmuir equation with correlation coefficients, R2, of 0.9991 and 0.9972, respectively. The adsorption of Pb2+ onto the layered alkali silicates from acidic aqueous solution was examined to obtain smaller amounts of adsorbed Pb2+ (0.32 mmol Pb/g magadiite and 0.34 mmol Pb/g octosilicate), confirming the important role of pH on the surface charge of the layered silicates in terms of ion exchange. The adsorption of Pb2+ reached equilibrium within 5 min for magadiite while it took 60 min for octosilicate. The difference was in the particle morphology; smoother diffusion of Pb2+ was possible through flower-shaped aggregates of particles of magadiite.

Влияние свинца и/или кадмия на сократительную функцию миокарда крыс при субхронической интоксикации и ее ослабление комплексом биопротекторов

Background : As by-products of copper smelting, lead and cadmium pollute both workplace air at metallurgical plants and adjacent territories. Their increased levels in the human body pose a higher risk of cardiovascular diseases. The objective of our study was evaluate changes in the rat myocardium contractile function following moderate subchronic exposure to soluble lead and/or cadmium salts and its attenuation by means of a complex of bioprotectors. Materials and methods : The subchronic exposure of rats was modelled by intraperitoneal injections of 3-H 2 O lead acetate and/or 2.5-H 2 O cadmium chloride in single doses, 6.01 mg of Pb and 0.377 mg of Cd per kg of body weight, respectively, 3 times a week during 6 weeks. The myosin heavy chains isoform ratio was estimated by gel electrophoresis. Biomechanical measurements were performed on isolated multicellular preparations of the myocardium (trabeculae and papillary muscles) from the right ventricle. Results : The subchronic lead exposure slowed down the contraction and relaxation cycle and increased myosin expression towards slowly cycling V3 isomyosins. Cadmium intoxication, on the contrary, shortened the contraction and relaxation cycle and shifted the ratio of isomyosin forms towards rapidly cycling V1. Following the combined exposure to lead and cadmium, some contractile characteristics changed in the direction typical of the effect of lead while others – in that of cadmium. We observed that the metal combination either neutralized or enhanced the isolated damaging effect of each heavy metal. The use of a complex of bioprotectors normalized the myocardial contractility impaired by the exposure to lead and cadmium either partially or completely. Discussion : Despite the changes in myocardial contractility following the subchronic lead and cadmium exposure, the mechanisms of heterometric regulation were maintained. The adverse cardiotoxic effect of the combination of these industrial contaminants may be weakened by administering a complex of bioprotectors.

EFFECT OF LEAD ON STRUCTURAL CHANGES IN LIVER OF WISTAR RATS UNDER THE CONDITIONS OF ACUTE EXPERIM

The purpose of this study was to evaluate the structural transformations of Wistar rats liver after oral administration of lead salts. Under the conditions of acute experiment during 5 days the Wistar rats were orally administered the lead acetate solution in the amount of 3 mg/kg. Histological studies were carried out at OSMU upon the completion of the experiment. Effect of toxic doses of lead causes symptoms of both steatosis and hydropic degeneration of the liver. It is assumed that the appearance of hepatic steatosis reflects the reaction of hepatocytes to hemic hypoxia caused by the action of lead, while the signs of hydropic degeneration expressed in varying degrees reflect its direct toxic effect.

Effects of Lead and/or Cadmium on the Contractile Function of the Rat Myocardium Following Subchronic Exposure and Its Attenuation with a Complex of Bioprotectors

Background: As by-products of copper smelting, lead and cadmium pollute both workplace air at metallurgical plants and adjacent territories. Their increased levels in the human body pose a higher risk of cardiovascular diseases. The objective of our study was evaluate changes in the rat myocardium contractile function following moderate subchronic exposure to soluble lead and/or cadmium salts and its attenuation by means of a complex of bioprotectors. Materials and methods: The subchronic exposure of rats was modelled by intraperitoneal injections of 3-H2O lead acetate and/or 2.5-H2O cadmium chloride in single doses, 6.01 mg of Pb and 0.377 mg of Cd per kg of body weight, respectively, 3 times a week during 6 weeks. The myosin heavy chains isoform ratio was estimated by gel electrophoresis. Biomechanical measurements were performed on isolated multicellular preparations of the myocardium (trabeculae and papillary muscles) from the right ventricle. Results: The subchronic lead exposure slowed down the contraction and relaxation cycle and increased myosin expression towards slowly cycling V3 isomyosins. Cadmium intoxication, on the contrary, shortened the contraction and relaxation cycle and shifted the ratio of isomyosin forms towards rapidly cycling V1. Following the combined exposure to lead and cadmium, some contractile characteristics changed in the direction typical of the effect of lead while others – in that of cadmium. We observed that the metal combination either neutralized or enhanced the isolated damaging effect of each heavy metal. The use of a complex of bioprotectors normalized the myocardial contractility impaired by the exposure to lead and cadmium either partially or completely. Discussion: Despite the changes in myocardial contractility following the subchronic lead and cadmium exposure, the mechanisms of heterometric regulation were maintained. The adverse cardiotoxic effect of the combination of these industrial contaminants may be weakened by administering a complex of bioprotectors.

Analytic and chemometric assessments of the native probiotic bacteria and inulin effects on bioremediation of lead salts.

Lead (Pb2+ ) is one of the most toxic heavy metals and can be found in various quantities in the environment. The five native probiotic bacteria and inulin were used to assess in vitro lead nitrate and lead acetate binding capacities, as well as removal potentials. The highest decrease in media pH was seen for samples containing a combination of Lactobacillus paracasei IRBC-M 10784, lead nitrate and inulin (5.30 ± 0.012). The presence of inulin in the environment accelerated decreases in the pH of all samples with no significance. In all groups, lead nitrate-containing samples included maximum pH decreases. From the highest to the lowest, the ability of lead removal was linked to Lactobacillus acidophilus PTCC-1932 (88.48%), Bifidobacterium bifidum BIA-7 (85.32%), Bifidobacterium lactis BIA-6 (85.24%), Lactobacillus rhamnosus IBRC-M 10782 (83.18%) and L. paracasei IRBC-M 10784 (80.66%). Most species included the highest decrease in lead nitrate. Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated that various functional groups (hydroxyl, carboxylic, carbonyl, amino and amide binds) on the bacterial cell wall were involved in lead ion binding during incubation. Principal component analysis of the FTIR results showed differences with respect to treated groups and control groups. The results obtained in the present study reveal that the simultaneous use of native probiotics and inulin can be an effective and safe approach for removing various toxic substances, especially Pb. © 2021 Society of Chemical Industry.