Girl or boy? Prenatal lead, cadmium and mercury exposure and the secondary sex ratio in the ALSPAC study

AbstractThe aim of this study was to evaluate the effect of prenatal exposure to lead, cadmium and mercury levels on the secondary sex ratio. Whole blood samples were collected from pregnant women enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) study at a median gestational age of 11 weeks and were analyzed for lead, cadmium and mercury. Regression analysis was used to identify associations between maternal lead, cadmium and mercury levels and the secondary sex ratio with adjustment for confounders. There was no evidence for associations between maternal lead, cadmium or mercury levels and the secondary sex ratio in this sample. It appears unlikely that alterations in the secondary sex ratio are influenced by exposure to heavy metals, but further work should be done in large cohorts in other countries to confirm these findings

Influence of Arbuscular Mycorrhizal Fungi on Growth and Heavy Metal (Cd & Hg) Uptake of Pinto Peanut (Arachis pintoi)

The pollution of the ecosystem by heavy metals is a real threat to the environment because metals cannot be naturally degraded like organic pollutants and persist in the ecosystem having accumulated in different parts of the food chain. Due to the acute toxicity of heavy metal contaminants, an urgent need to develop low-cost, effective, and sustainable methods to remove or detoxify them from the environment. A study to investigate the growth and heavy metal (Cd and Hg) absorption capacity of Arachis pintoi associated with arbuscular mycorrhizal fungi (AMF) was conducted. The heavy metal (Cadmium and Mercury) uptake of A. pintoi inoculated with arbuscular mycorrizal fungi was also determined and compared by quantifying the heavy metal absorbed by the plants through Atomic Spectrophotometry. Randomized Complete Block Design (RCBD) was used as the experimental design with four treatments replicated three times each for Cadmium and mercury were made. The analysis of variance suggests a highly significant difference in the main effect of treatments, the main effect in weeks and their interaction in cadmium and mercury set-up. The results have found out that Treatment 3 (Heavy metal without AMF) in heavy metal cadmium and mercury has the highest heavy metal uptake. The study further recommend that A. pintoi, a widely available and abundant plant species with mycorrhyzal fungi interaction will be a beneficial procedure in reducing heavy metal pollution in soil

Relation between Concentrations of Lead, Cadmium and Mercury in Cord Blood and Prematurity in the Sidi Bel Abbes Region (West of Algeria)

Background: Exposure to heavy metals such as lead, cadmium and mercury during pregnancy carries a great risk to the mother as well as the fetus. Methods: Lead, cadmium and mercury were measured in umbilical cord blood samples of 3 groups women (30 women’s for lead, 30 cadmium and 10 from mercury) in maternity of Sidi Bel Abbes region in Algeria between 2016 and 2017.The objective of this study was to measure in the blood of the umbilical cord the concentration of lead (Pb), mercury (Hg) and cadmium (Cd), and to evaluate the relationship between these levels and prematurity. The lead, cadmium and mercury levels were measured by atomic absorption. Results: The study showed obvious variations in, maternal characteristics. The results revealed several factors predisposing to prematurity. The mean concentrations of cord blood lead, cadmium and mercury were; 18.97 µg/L, 0.26 µg/L, and6.20 nmol/L, respectively.  There was a highly significant direct correlation between cord lead concentrations and gestational age(r=0.43; P = 0.017), and we found that gestational age and birth weight inversely correlated with cord mercury concentration (r=0.44 and r=0.57 respectively).No correlation was observed between cord cadmium concentrations and gestational age. Conclusion: This study has shown that pregnant women in this region were exposed to high levels for heavy metalswhich need an intervention. Keywords: Lead. Cadmium, Mercury, Pregnancy, Prematurity, Fetal exposure, Algeria

Mercury and cadmium trigger expression of the copper importer Ctr1B, which enables Drosophila to thrive on heavy metal-loaded food

Organisms from insects to mammals respond to heavy metal load (copper, zinc, cadmium, and mercury) by activating the metal-responsive transcription factor 1 (MTF-1). MTF-1 binds to short DNA sequence motifs, termed metal response elements, and boosts transcription of a number of genes, notably those for metallothioneins. In Drosophila, MTF-1 somewhat counter-intuitively also activates transcription of a copper importer gene (Ctr1B) in response to copper starvation. Here, we report that mutant flies lacking Ctr1B are extremely sensitive to cadmium and mercury treatment, but can be rescued by excess copper in the food. We thus propose that copper, by competing for binding sites on cellular proteins, alleviates the toxic effects of mercury and cadmium. Such a scenario also explains a seemingly fortuitous metal response, namely, that cadmium and mercury strongly induce the expression of a Ctr1B reporter gene. Thus, the transcription enhancer/promoter region of the Ctr1B copper importer gene is subject to three modes of regulation. All of them depend on MTF-1 and all make biological sense, namely, (i) induction by copper starvation, (ii) repression by copper abundance, and (iii), as shown here, induction by cadmium or mercury at normal copper suppl

Review of trace toxic elements (Pb, Cd, Hg, As, Sb, Bi, Se, Te) and their deportment in gold processing. Part 1: Mineralogy, aqueous chemistry and toxicity

A literature review on the deportment of trace toxic elements (Pb, Cd, Hg, As, Sb, Bi, Se, and Te) in gold processing by cyanidation is presented which compiles the current knowledge in this area and highlights the gaps. This review, together with further research on the gaps in the thermodynamics and kinetics of these systems, aims to support the development of computer models to predict the chemical speciation and deportment of these elements through the various stages of the gold cyanidation process. The first part of this review is a collation of the relevant information on trace element mineralogy, aqueous chemistry and toxicity, together with a comparison of two available software packages (JESS and OLI) for thermodynamic modelling. Chemical speciation modelling can assist in understanding the chemistry of the trace toxic elements in gold cyanidation solutions which remains largely unexplored. Many significant differences exist between the predicted speciation of these trace elements for different types of modelling software due to differences in the thermodynamic data used, the paucity of data that exists under appropriate non-ideal conditions, and the methods used by the software packages to estimate thermodynamic parameters under these conditions. The toxicity and environmental guidelines of the chosen trace element species that exist in aqueous solutions are discussed to better understand the health and environmental risks associated with the presence of these elements in gold ores

Lead, Cadmium, and Mercury Concentration Levels in Some Commercial Fish From the Arabian Sea and the Gulf of Aden During the Years 2020–2022

This study was conducted to determine and evaluate the heavy metal concentrations levels: lead (Pb), cadmium (Cd), and mercury (Hg) in the meat of some commercial fish species: Grouper (Epinephelus areolatus), Emperor (Lethrinus nebulosus) and Cuttlefish (Sepia Pharaonis). A total of 84 fish samples were caught and collected from different sites in the Gulf of Aden and the Arabian Sea between January 2020 and December 2022. Some of them were sold in the cities markets of Hadhramout governorate- Yemen, and some of them were exported abroad. All samples were analyzed at the laboratories of the Faculty of Environmental Sciences and Marine Biology- Hadhramout University, where atomic absorption spectrometer was used in the process of analyzing elements, following the generally accepted scientific methods. The results of the study showed that the mean concentrations of lead, cadmium, and mercury in the Grouper samples were (0.1225, 0.0101, and 0.0098 ppm) respectively. In Emperor the mean concentrations of lead, cadmium, and mercury reached (0.1228, 0.0108, and 0.0084 ppm) respectively, while in Cuttlefish, lead, cadmium, and mercury reached (0.1220, 0.0143, and 0.0063 ppm) respectively. All these values remained even lower than the minimum permissible limits, whether according to Yemeni or European standards. The results of one-way analysis of variance (ANOVA) did not show any significant difference in lead concentrations among study\u27s fish (P\u3e0.05), whereas, it indicated that there were significant differences between cadmium and mercury. Among years, (ANOVA) did not indicate any significantly difference (P\u3e0.05) in cadmium concentration, whereas, there were significant difference (P\u3c0.05) in lead and mercury. This study concluded by providing some important recommendations to local authorities and competent scientific centers in this field

Сравнительная оценка метаболических нарушений при действии малых доз кадмия и ртути

На підставі даних, одержаних в експериментах на лабораторних тваринах, показано, що в суспільній свідомості небезпека кадмію невиправдано занижена в порівнянні зі ртуттю. Обґрунтовується недостатність і обмеженість пояснення токсичності важких металів, зокрема кадмію і ртуті, однієї лише формулою «тіолові отрути». Вивчені розподіл і токсикокінетика кадмію і ртуті в органах і тканинах щурів, динаміка рівнів металотіонеїнів при введені тваринам цих важких металів внутрішньошлунково. Доводиться визначаюче значення хімічних і физико-хімічних властивостей елементів на їх токсикологічні характеристики. Показані схожість і відмінність кадмію і ртуті в плані токсикодінамики і токсикокінетики їх сполук.On the basis of the experimental data it is shown that in public consciousness the danger of cadmium is unfairly underestimated in comparison with mercury. Insufficiency and limitation of an explanation of toxicity of heavy metals, in particular cadmium and mercury, by only one formula " thiol poisons " is proved. Distribution and toxicological genetics of cadmium and mercury in the bodies and tissues of rats, dynamics of metallotieneines levels at a priming of animals by the heavy metals under study are investigated in vivo. The leading value of chemical and physical and chemical properties of elements on their toxicological characteristics is proved. Similarity and distinction of cadmium and mercury from the point of view of toxicodynamics and toxicokinetics of their compounds are shown

Accumulation of Heavy Metals in Franciscanas from Buenos Aires Province, Argentina

Marine mammals accumulate heavy metals in their tissues at different concentrations according to trophic levels and environmental conditions. The franciscana (Pontoporia blainvillei) is a small coastal species inhabiting the marine and estuarine areas of the Southwestern Atlantic Ocean. Its diet includes numerous species of small fish, squid and crustaceans. The aims of this study were to (i) assess the heavy metal concentration and burden distribution in different franciscana age classes and sex, and to (ii) evaluate both the accumulation processes and the transplacental transference of zinc, cadmium, copper and total mercury. Heavy metal concentrations (wet weight) were determined in eighteen dolphins by Atomic Absorption Spectrophotometry (AAS), by the cold vapour technique (mercury) or with air/acetylene flame (cadmium, zinc and copper). Liver showed the highest concentrations of mercury (max. 8.8 mg/g), zinc (max. 29.7 mg/g) and copper (max. 19.0 mg/g), whereas the highest cadmium concentrations (max. 6.7 mg/g) were found in kidney. Adults contained the highest concentrations for all heavy metals, followed by juveniles and calves in decreasing order, suggesting an age-related accumulation. No differences (p<0.05) were found between sexes within each age class. Organ burden distribution followed the same pattern for all metals and age classes: liver tissues contained maximum burdens. Mercury concentrations were higher than those of cadmium in both foetuses and newborns; and neither metal could be detected in the foetus. The analysed data suggested differences in the placental transference between metals, being significant for mercury and almost null in the case of cadmium. We can conclude that franciscana accumulates heavy metals and, due to its coastal distribution, it may be considered as a biomonitor of its environment. SPANISH: Los mamíferos marinos acumulan metales pesados en sus tejidos cuyas concentraciones están en relación con su nivel trófico y las condiciones ambientales. La franciscana (Pontoporia blainvillei) es una especie costera que habita áreas marinas y estuariales en el Atlántico Sudoccidental. Su dieta está constituída por peces, como item alimentario principal, calamares y crustáceos. El objetivo del presente trabajo es estudiar la distribución de metales pesados en diferentes clases de edad y en ambos sexos, evaluando procesos de acumulación y cargas de cadmio, mercurio total, cinc y cobre. Las concentraciones de metales pesados (en peso húmedo) fueron determinadas en dieciocho delfines por Espectrofotometría de Absorción Atómica (EAA), usando la técnica de vapor frío (mercurio) o llama de aire/acetileno (cadmio, cinc y cobre). El hígado presentó las concentraciones más altas de mercurio (máx. 8,8 mg/g), cinc (máx. 29,7 mg/g) y cobre (máx. 19,0 mg/g), mientras que las más altas de cadmio (máx. 6,7 mg/g) fueron encontradas en el riñón. Los adultos presentaron los niveles más altos, presentando los juveniles y cachorros concentraciones menores, lo cual sugirió una acumulación con la edad. No se encontraron diferencias significativas (p < 0,05) entre sexos dentro de cada clase de edad. Las cargas de metales pesados en los órganos presentaron la misma disribución para todos los metales y clases de edad. Los valores más altos fueron encontrados en el hígado, incluyendo los correspondientes a cadmio. Las concentraciones de mercurio y cadmio fueron no detectables en el feto, mientras que las de mercurio fueron superiores a las de cadmio en los cachorros. Los datos encontrados en el feto sugieren una transferencia nula a través de la placenta. Podemos concluir que P.blainvillei acumula metales pesados en sus tejidos y debido a su distribución costera, esta especie puede ser considerada como un biomonitor de su ambiente

A Fluorescent Dissymmetric Thiosemicarbazone Ligand Containing a Hydrazonequinoline Arm and Its Complexes with Cadmium and Mercury

A new dissymmetric thiosemicarbazone ligand containing a hydrazonequinoline arm, H2AMeTsQ, and its chloride salt, [H3AMeTsQ]Cl, were synthesized. Nine new complexes of cadmium and mercury with different structural characteristics were obtained under different reaction conditions as the ligand charge can be controlled by varying the amount of base. 113Cd and 199Hg NMR spectroscopy together with X-ray diffraction indicated that the complexes form monomeric and dimeric structures and even a coordination polymer. Fluorescence spectroscopy showed that both protonated and neutral forms of the ligand were fluorescent as well as some of their cadmium and mercury derivatives. The fluorescence intensity decreased upon complexation and in some complexes a shift of the emission maximum was also observedWe thank César J. Pastor from “Servicio Interdepartamental de Investigación” (SidI) of the Universidad Autónoma de Madrid (Spain) for the crystal measurements. We also thank the Ministerio de Economía y Competitividad, Instituto de Salud Carlos III for funding (project number PS09/00963