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1.
Critical aspects of the physiological interactions between lead and magnesium.
Wyparło-Wszelaki, M, Machoń-Grecka, A, Wąsik, M, Dobrakowski, M
Journal of biochemical and molecular toxicology. 2022;(2):e22964
Abstract
Despite technological progress, exposure to lead is an ongoing problem. There are many mechanisms governing the toxic effects of lead on the human body. One such mechanism involves the interaction of this xenobiotic with bivalent metal ions, including magnesium. Literature data suggest that the competition between these elements for binding sites at the molecular and cellular levels, as well as at the systemic level, may represent an important aspect of lead toxicity in the human body. This is especially clear in the context of oxidative stress, immune response, and gene expression modifications. This review aims to summarize current knowledge regarding these issues.
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The association of cadmium and lead exposures with red cell distribution width.
Peters, JL, Perry, MJ, McNeely, E, Wright, RO, Heiger-Bernays, W, Weuve, J
PloS one. 2021;(1):e0245173
Abstract
Elevated red blood cell distribution width (RDW), traditionally an indicator of anemia, has now been recognized as a risk marker for cardiovascular disease incidence and mortality. Experimental and acute exposure studies suggest that cadmium and lead individually affect red blood cell production; however, associations between environmental exposures and RDW have not been explored. We evaluated relationships of environmental cadmium and lead exposures to RDW. We used data from 24,607 participants aged ≥20 years in the National Health and Nutrition Examination Survey (2003-2016) with information on blood concentrations of cadmium and lead, RDW and socio-demographic factors. In models adjusted for age, sex, race/ethnicity, education, poverty income ratio, BMI, alcohol consumption, smoking status and serum cotinine, RDW was increasingly elevated across progressively higher quartiles of blood cadmium concentration. A doubling of cadmium concentration was associated with 0.16 higher RDW (95% CI: 0.14, 0.18) and a doubling of lead concentration with 0.04 higher RDW (95% CI: 0.01, 0.06). Also, higher cadmium and lead concentrations were associated with increased odds of high RDW (RDW>14.8%). The associations were more pronounced in women and those with low-to-normal mean corpuscular volume (MCV) and held even after controlling for iron, folate or vitamin B12 deficiencies. In analysis including both metals, cadmium remained associated with RDW, whereas the corresponding association for lead was substantially attenuated. In this general population sample, blood cadmium and lead exposures were positively associated with RDW. The associations may indicate hemolytic or erythropoietic mechanisms by which exposure increases mortality risk.
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Identification of the endosymbionts from Sulla spinosissima growing in a lead mine tailings in Eastern Morocco as Mesorhizobium camelthorni sv. aridi.
Lamin, H, Alami, S, Bouhnik, O, Bennis, M, Benkritly, S, Abdelmoumen, H, Bedmar, EJ, Missbah-El Idrissi, M
Journal of applied microbiology. 2021;(3):948-959
Abstract
AIMS: To identify the bacteria nodulating Sulla spinosissima growing profusely in a lead and zinc mine tailings in Eastern Morocco. METHODS AND RESULTS In all, 32 rhizobial cultures, isolated from root nodules of S. spinosissima growing in soils of the mining site, were tolerant to different heavy metals. The ERIC-polymerase chain reaction (PCR) fingerprinting analysis clustered the isolates into seven different groups, and the analysis of the 16S rRNA sequences of four selected representative strains, showed they were related to different species of the genus Mesorhizobium. The atpD, glnII and recA housekeeping genes analysis confirmed the affiliation of the four representative strains to Mesorhizobium camelthorni CCNWXJ40-4T , with similarity percentages varying from 96·30 to 98·30%. The sequences of the nifH gene had 97·33-97·78% similarities with that of M. camelthorni CCNWXJ40-4T ; however, the nodC phylogeny of the four strains diverged from the type and other reference strains of M. camelthorni and formed a separated cluster. The four strains nodulate also Astragalus gombiformis and A. armatus but did not nodulate A. boeticus, Vachellia gummifera, Prosopis chilensis, Cicer arietinum, Lens culinaris, Medicago truncatula, Lupinus luteus or Phaseolus vulgaris. CONCLUSIONS Based on similarities of the nodC symbiotic gene and differences in the host range, the strains isolated from S. spinosissima growing in soils of the Sidi Boubker mining site may form a different symbiovar within Mesorhizobium for which the name aridi is proposed. SIGNIFICANCE AND IMPACT OF THE STUDY In this work, we show that strains of M. camelthorni species nodulating S. spinosissima in the arid area of Eastern Morocco constitute a distinct phylogenetic clade of nodulation genes; we named symbiovar aridi, which encompasses also mesorhizobia from other Mediterranean desert legumes.
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Bradyrhizobium sp. sv. retamae nodulates Retama monosperma grown in a lead and zinc mine tailings in Eastern Morocco.
Lamin, H, Alami, S, Lamrabet, M, Bouhnik, O, Bennis, M, Abdelmoumen, H, Bedmar, EJ, Missbah-El Idrissi, M
Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]. 2021;(2):639-649
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Abstract
The aim of this work was to characterize and identify some bacteria isolated from the root nodules of Retama monosperma grown in Sidi Boubker lead and zinc mine tailings. Very few root nodules were obtained on the root nodules of R. monosperma grown in these soils. The three bacteria isolated from the root nodules were tolerant in vitro to different concentrations of heavy metals, including lead and zinc. The rep-PCR experiments showed that the three isolates have different molecular fingerprints and were considered as three different strains. The analysis of their 16S rRNA gene sequences proved their affiliation to the genus Bradyrhizobium. The analysis and phylogeny of the housekeeping genes atpD, glnII, gyrB, recA, and rpoB confirmed that the closest species was B. valentinum with similarity percentages of 95.61 to 95.82%. The three isolates recovered from the root nodules were slow-growing rhizobia capable to renodulate their original host plant in the presence of Pb-acetate. They were able to nodulate R. sphaerocarpa and Lupinus luteus also but not Glycine max or Phaseolus vulgaris. The phylogeny of the nodA and nodC nodulation genes as well as the nifH gene of the three strains showed that they belong to the symbiovar retamae of the genus Bradyrhizobium. The three strains isolated could be considered for use as inoculum for Retama plants before use in phytoremediation experiments.
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Inactivation of GAP-43 due to the depletion of cellular calcium by the Pb and amyloid peptide induced toxicity: An in vitro approach.
Ayyalasomayajula, N, Bandaru, M, Dixit, PK, Ajumeera, R, Chetty, CS, Challa, S
Chemico-biological interactions. 2020;:108927
Abstract
Environmental pollutant, Lead (Pb) is known to induce neurotoxicity in human. The central nervous system is the most vulnerable to the minute levels of Pb induced toxicity. Pb has been linked to Alzheimer's disease (AD) as a probable risk factor, as it shows epigenetic and developmental link associated with Alzheimer's disease-like pathology. Beta amyloid peptides were considered as the crucial factors in the beta amyloid plaque formation in Alzheimer's disease brain. In this context, we investigated the molecular mechanism involved in the development of Pb induced Alzheimer's disease in in vitro. Previous data from our studies have reported that Pb in the presence of beta Amyloid peptide (1-40) and (25-35) induces more apoptosis than individual exposures. Here, to further evaluate the molecular mechanism underlying Pb induced Alzheimer's disease; we focussed on the involvement of calcium signalling in inducing cell death. Our experimental observations suggesting that Pb in the presence of beta amyloid peptide alters intracellular calcium levels, which leads to the increased beta-secretase activity, which further promotes the generation of beta amyloid peptides. It also showed depression in the levels of GAP-43 expression, inhibition of PKC activity and altering synaptic activity further leads to cell death.
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In situ effects of Lathyrus sativus- PGPR to remediate and restore quality and fertility of Pb and Cd polluted soils.
Abdelkrim, S, Jebara, SH, Saadani, O, Abid, G, Taamalli, W, Zemni, H, Mannai, K, Louati, F, Jebara, M
Ecotoxicology and environmental safety. 2020;:110260
Abstract
Rehabilitation of heavy metals contaminated soils using association between legumes and beneficial rhizospheric microorganisms such as plant growth-promoting bacteria (PGPR) is a major challenge in agronomy. The present study focuses on assessing the impact of field inoculation with I1 (Rhizobium leguminosarum (M5) + Bacillus simplex + Luteibacter sp. + Variovorax sp.) and I5 (R. leguminosarum (M5) + Pseudomonas fluorescens (K23) + Luteibacter sp. + Variovorax sp.) on growth and phytoremediation potential of Lathyrus sativus plants as well as soil quality and fertility. The experimentation was carried out in mine tailings of northern Tunisia. Obtained Results indicated that the in situ inoculation with I1 and I5 significantly increased the shoots (47% and 22%) and roots dry weights (22% and 29%), as well as nodules number (48% and 31%), respectively, compared to uninoculated plants. The maximum Pb accumulation in the above-ground tissue was recorded in plants inoculated with I5 (1180.85 mg kg-1 DW). At the same time, we noticed a reduction in total Pb and Cd in the rhizosphere of inoculated plots mainly in those inoculated with I5 reaching 46% and 61%, respectively, compared to uninoculated plots. Likewise, I5 inoculum significantly enhanced soil total nitrogen (35%) and available phosphorus (100%), as well as β-glucosidase (16%), urease (32%) and alkaline phosphatase (12%) activities. Here we demonstrate the usefulness of L. sativus inoculated with I5 inoculum formed by mixing efficient and heavy metals resistant PGPR to boost an efficient reclamation of Cd and Pb contaminated soils and, ultimately, to improve their quality and fertility.
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Perspective on Cadmium and Lead in Cocoa and Chocolate.
Abt, E, Robin, LP
Journal of agricultural and food chemistry. 2020;(46):13008-13015
Abstract
Cocoa and chocolate can contain cadmium (Cd) and lead (Pb) from natural and anthropogenic sources. This perspective provides background on the origin, occurrence, and factors affecting Cd and Pb levels in chocolate products as well as ongoing international efforts to mitigate Cd and Pb in these popular foods, particularly the higher Cd levels observed in some cocoa and chocolate originating from parts of Latin America. Information on factors contributing to higher Cd levels in Latin America, including elevated soil Cd, is increasing, but more work is needed to identify successful mitigation methods.
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Interpretation of Population Health Metrics: Environmental Lead Exposure as Exemplary Case.
Staessen, JA, Thijs, L, Yang, WY, Yu, CG, Wei, FF, Roels, HA, Nawrot, TS, Zhang, ZY
Hypertension (Dallas, Tex. : 1979). 2020;(3):603-614
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Abstract
Our objective was to gain insight in the calculation and interpretation of population health metrics that inform disease prevention. Using as model environmental exposure to lead (ELE), a global pollutant, we assessed population health metrics derived from the Third National Health and Nutrition Examination Survey (1988 to 1994), the GBD (Global Burden of Disease Study 2010), and the Organization for Economic Co-operation and Development. In the National Health and Nutrition Examination Survey, the hazard ratio relating mortality over 19.3 years of follow-up to a blood lead increase at baseline from 1.0 to 6.7 µg/dL (10th-90th percentile interval) was 1.37 (95% CI, 1.17-1.60). The population-attributable fraction of blood lead was 18.0% (10.9%-26.1%). The number of preventable ELE-related deaths in the United States would be 412 000 per year (250 000-598 000). In GBD 2010, deaths and disability-adjusted life-years globally lost due to ELE were 0.67 million (0.58-0.78 million) and 0.56% (0.47%-0.66%), respectively. According to the 2017 Organization for Economic Co-operation and Development statistics, ELE-related welfare costs were $1 676 224 million worldwide. Extrapolations from the foregoing metrics assumed causality and reversibility of the association between mortality and blood lead, which at present-day ELE levels in developed nations is not established. Other issues limiting the interpretation of ELE-related population health metrics are the inflation of relative risk based on outdated blood lead levels, not differentiating relative from absolute risk, clustering of risk factors and exposures within individuals, residual confounding, and disregarding noncardiovascular disease and immigration in national ELE-associated welfare estimates. In conclusion, this review highlights the importance of critical thinking in translating population health metrics into cost-effective preventive strategies.
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Effects of organic matter components and incubation on the cement-based stabilization/solidification characteristics of lead-contaminated soil.
Ge, S, Pan, Y, Zheng, L, Xie, X
Chemosphere. 2020;:127646
Abstract
Stabilization/solidification (S/S) has been studied since 1950s and widely used for the treatment of potentially toxic elements (PTEs). The coexistence of organic matter (OM) and PTEs can cause a very complicated mechanism for cement-based S/S applications and bring challenges from both scientific and engineering perspectives. To fill in the knowledge gap, this paper investigates for the first time the effects on S/S characteristics of OM components and incubation, which are the two main factors that result in the inconsistency in the leaching characteristics from the available studies. OM samples with different components (humic acid (HA) and fulvic acid (FA)) and contents were mixed into lead-contaminated soil and incubated for different durations of up to 90 days. The experimental results show that the strength of stabilized soils increases with increasing incubation duration and the lead leaching concentration of stabilized soils is decreased by 60.7%-83.6% from zero to 90 days. The lead leaching concentration of the HA group, which is 144.0% higher with no incubation than the non-OM group, becomes 58.3% lower with 90 days of incubation. The leaching concentration of the FA group remains much higher than those of the other groups. Finally, a competing mechanism of HA-weakening cement hydration reactions and stabilizing lead with a critical incubation duration of 14 days-is proposed, together with a cooperating mechanism of FA-weakening cement hydration reactions and releasing lead.
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Systematic Review of the Literature of Factors Affecting the Exposure and the Levels of Lead in Human Breast Milk.
Cherkani-Hassani, A, Ghanname, I, Benitez-Rexach, AM, Mouane, N
Reviews of environmental contamination and toxicology. 2020;:97-129
Abstract
Human milk may sometimes contain chemical contaminants, which could have adverse effects on neonates or nursing infants. Lead (Pb) is of considerable interest due to its toxicity and occurrence. Furthermore, it has been suggested that human milk is a significant potential source of lead exposure to nursing infants. A systematic literature search in PubMed, Science Direct, and Google Scholar databases was performed to identify relevant studies, published in English until 2017, that investigated and explored common factors affecting the level of lead in human milk among lactating women around the world. Forty-nine papers were rated and explored the effect of one or several factors on the level of lead in human milk from 28 countries and carried out over a wide time frame from 1983 to 2017 and through Europe, Asia, America, and Africa, reviewing more than 5,000 subjects. Place of residence, maternal age, stage of lactation, smoking habits, maternal dietary intakes, and parity were the mostly assessed factors among the studies and considered as the main factors affecting Pb levels in BM. Other factors were not studied well enough and considered minor because few surveys evaluated their impacts. However, the literature findings are very controversial.