Low Pb Concentrations Research Articles

Combining biomonitoring data in children and biokinetic modeling to guide decision-making for health risk management – a case study on lead emitted by a smelter in Rouyn-Noranda, Canada

This work aims at illustrating the benefit of combining lead (Pb) biomonitoring data with toxicokinetic simulations in order to confidently identify the risk management intervention that favors the greatest reduction of blood Pb level (BLL) in children exposed to smelter emissions in a mining city from northern Quebec, Canada. The U.S. EPA’s Integrated Exposure and Uptake BioKinetic (IEUBK) model was parametrized with relevant environmental concentrations data to simulate background BLL (in average Canadian children) and local BLL (in children from the concerned community). The resulting simulations were compared with corresponding BLL biomonitoring data. Next, soil and air concentrations were lowered sequentially within the IEUBK model to values specified in Quebec’s environmental regulations. IEUBK simulations predicted mean BLL values that were similar to the measured biomonitoring values, for both the background (predicted: 0.56 vs observed: 0.5 µg/dL) and local BLL (1.24 vs 1.16 µg/dL). Repeating local BLL simulations with lower Pb concentration in the air or soil based on regulatory guidelines showed a much stronger impact of decreasing soil Pb as compared to air Pb. Concluding, this work shows that soil remediation should be prioritized to lower local children’s BLL. Also, the combined use of case-specific environmental Pb levels and biomonitoring data can increase the level of confidence toward an IEUBK-driven identification of the most effective measure for lowering children’s BLLs, in the ≤2 µg/dL domain.

Structural design of cellulose-hyperbranched double-network for enhanced intramolecular diffusion kinetics of heavy metal ion capture processes

Extracting cellulose from agricultural residues and converting it into environmentally friendly adsorbents to solve the heavy metal contamination problem of groundwater and farmland is an effective strategy to achieve high-value utilization of agricultural residues. Herein, we propose a streamlined crosslinking strategy to fabricate a cellulose-based amphoteric hyperbranched adsorbent (MAHPA) in a controlled manner. The strategy involves synthesizing the amphoteric hyperbranched functional reagent first and then crosslinking it with microcrystalline cellulose (MCC). This approach simplifies the complexity of the multi-component cross-linking system, resulting in a conversion rate of reaction reagents exceeding 99 %. MAHPA, with a three-dimensional hyperbranched structure (degree of branching: 0.77), exhibits a high swelling rate (247.62 %) and high densities of carboxyl (7.05 mmol·g−1) and amino (8.27 mmol·g−1) groups. Moreover, the cellulose-hyperbranched double-network structure of MAHPA greatly enhances the intramolecular diffusion kinetics of heavy metal ions on MAHPA, enabling it to complete the removal of low concentrations of Cr(VI), As(V), Pb(II), and Cd(II) within 20 min. Interestingly, MAHPA demonstrates excellent synchronous capture performance for Cr(VI), As(V), Pb(II), and Cd(II) in groundwater at a velocity of 1.60 × 10−2 m·s−1. Meanwhile, applying MAHPA can realize the safe utilization of Cd-As contaminated soil. This work offers a general strategy for the structural design of cellulose-based hyperbranched adsorbent holding great promise as heavy metal contaminated groundwater and soil remediation field.

Spraying or fertigation? looking for the better method in terms of the lower concentration of Pb and Ni in greenhouse cucumber.

This study was conducted to investigate the status of Lead (Pb) and Nickel (Ni) in greenhouse cucumber affected by fertigation and spraying as a factorial split plot arrangement based on a randomized complete block design (RCBD) with three replications at Soil and Water Research Institute, Karaj, Iran in 2023. The main and sub-plots were respectively fertigation and spraying that was applied in two levels [the minimum permissible concentration of these metals in granular triple super phosphate fertilizer (five ppm Pb and five ppm Ni) as the control treatment, and the maximum permissible concentration of Pb and Ni in granular triple super phosphate fertilizer (50 ppm Pb and 100 ppm Ni)]. Spraying was done in three modes (spraying leaves, leaves + fruit, and fruit). Based on the results, the highest concentration of Pb in the fruit (fruit peel + fruit flesh) (0.295 mg/kg DW) was recorded in the fertigation + spraying with the maximum permissible concentrations of Pb and Ni treatments. A general comparison between the two fertilization methods showed that the sprayingmethod accumulated a higher concentration of Pb in the fruit (i.e., peel + flesh) than the fertigation method. The reverse of this status happened for Ni, so the fertigation method accumulated a higher concentration of Ni in the fruit (skin + flesh) compared to the spraying method. On average, the order of Pb concentration in different organs was as follows: leaf (0.765mg/kg) > fruit peel (0.232mg/kg) > fruit peel + flesh (0.174mg/kg) > fruit flesh (0.129mg/kg). This order for Ni was as follows: fruit flesh (0.597mg/kg) > fruit peel + flesh (0.345mg/kg) > leaf (0.3mg/kg) > fruit peel (0.175mg/kg). These orders show that the status of the heavy metals in plant tissues is related to the nature of the metal, the type of the organ, and the method of fertilization.

Provenancing copper in the middle Shang period through isotopic analysis of metallurgical remains

Archaeological investigations recently conducted at the site of Tajiasi, a Middle Shang bronze casting workshop, have led to the discovery of abundant metallurgical micro-remains from various stages of bronze production processes. Lead isotope analysis of these samples has given fresh insights into the discussion about the origin of the metal sources employed during this period. The copper melting and refining slags, characterized by 206Pb/204Pb around 18.0 and very low lead concentrations (＜4,000 ppm), provided the first reliable indicator about the geological origin of copper used in the Middle Shang period. It is suggested the Jiurui metallogenic district in the Middle Yangtze River, home to the Shang period copper smelting site of Tongling, was the copper source for the Taijiasi site. On the other hand, alloying slags and bronze objects bearing highly radiogenic lead (206Pb/204Pb > 19.0) show an elevated, but still relatively low Pb content (＜2 wt%), suggesting that the source of tin introduced Pb which was characterized by HRL. Items including alloying slags, dross, spillages and bronze objects have similar HRL characteristics to the Middle Shang bronzes from other sites. This result indicated the Taijiasi site was involved in a multi-line metal circulation during this period, and elucidated the complexity and multiplicity of supply networks for different kinds of metals in the Middle Shang period. It also highlighted the great potential of copper melting and refining slags for detecting the copper provenance.

Two electrochemical sensors based on pencil graphite electrodes modified with azo dye and a novel Schiff base for lead and cadmium ion quantification

This research introduces a cost-effective and straightforward approach to fabricating two novel electrochemical sensors. The initial novel sensor, termed AZOD/PLE, involves coating the surface of a pencil lead electrode (PLE) with the azo dye molecule (AZOD). The second novel sensor, named HDBE/PLE, is created by coating the pencil lead electrode (PLE) with a newly synthesized novel Schiff base molecule (HDBE), characterized through techniques such as IR, 1H NMR, and 13C NMR. The reason for the choice of the modifier materials in this research is their complexing ability with metal ions since they contain electron donor atoms such as O and N, which can form coordination bonds with the toxic heavy metal’s ions, cadmium and lead. This is the first time using the azo dye molecule (AZOD) and the novel Schiff base molecule (HDBE) as modifiers on PLE. The characterization of the electrode surfaces was made by energy-dispersive X-ray spectroscopy (EDS), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). The surface morphology of the electrode was investigated by scanning electron microscopy (SEM). CV results indicate that the modified electrodes possess larger electroactive surface areas compared to the bare PLE. Square wave voltammetry (SWV) results demonstrate that both sensors exhibit high sensitivity in detecting low concentrations of Cd (II) and Pb (II) in tris-HCl buffer (0.1 M) for both single-metal and multi-metal solutions. These sensors can be easily produced in a single step and exhibit excellent selectivity, stability, reproducibility, and repeatability, making them well-suited for detecting Pb (II) and Cd (II) in aqueous environments.

Anatomy and genesis of the world’s largest carbonate-hosted Zn-Pb deposit: New insights from ore characteristics, Zn-Pb-C-O isotopes, and trace element constraints of the Huoshaoyun deposit, Karakorum Range, Xinjiang

The Huoshaoyun deposit in the Karakorum area of NW China is the world’s largest zinc-lead carbonate ore deposit. Here we investigate the genesis of the mineralization based on multiproxy investigations. The deposit contains zinc-lead carbonate and sulfide minerals, with smithsonite (Smt), cerussite (Cer), and sulfides accounting for 85%, 10%, and 5% of the total lead and zinc resources, respectively. Three ore-forming stages, involving Smt, Cer, and sulfides ores were summarized. The Smt mineralization is characterized by veined, massive, and stratified Smt forming horizontal sedimentary layered ore and vertical feeder veins similar to the SEDEX-type deposits. The sulfide and Cer veins display typical hydrothermal characteristics and are superimposed on the massive Smt ores. The Smt ores show high Li, Be, Cr, Y, Ba, Nd, Yb, and Zr contents, whereas the Cer veins have extremely high Sr contents (up to 3814–9174 ppm) and low Zr contents (less than 0.01 ppm). Galena and sphalerite show higher Cd concentrations compared to Smt and Cer ores.The Smt ores differ with different spatial locations, with Smt ores formed at the vent have δ66Zn values of +0.15‰ to +0.21‰, the massive Smt formed close to the vent show a value of +0.13‰, and those formed away from the vent show a value of 0.05‰, all values being close to 0. The sulfides have δ66Zn values of −0.09‰ to +0.04‰. The C-O isotopes of Smt ores are similar to both altered and unaltered host limestone, suggesting that the limestone was a potential source for carbon and oxygen. Quartz with veined Smt shows magmatic signatures with δ18OVSMOW of +1.14‰ to +2.23‰, high Pb (115–401 ppm) and Zn concentrations (390–997 ppm), whereas quartz associated with sulfide has meteoric fluid signature with the lowest δ18OVSMOW (−14‰ to −10.7‰), low Pb (11.6–49.0 ppm) and Zn (18.1–72.8 ppm) concentrations. The temperature of equilibration computed based on oxygen isotope fractionation between Smt and coeval quartz indicate a dual source with that of quartz derived from an aqueous fluid, whereas the source for Smt might involve CO2 or HCO3−.We trace multiple metallogenic stages for this deposit including exhalation, hydrothermal deposition, and fault-controlled sulfide vein formation. The largest orebody (III-1) preserves a 16 Mt reserve of Zn and was formed by crust-mantle interaction at ca. 195 Ma in the early development of the Linjitang post-arc rift system. Fluid convection, zinc enrichment driven by granitic magma, volcanic activity, and karst alteration induced by acid rain in a lagoonal environment promoted ore enrichment.

Pb Pollution Stress in Alnus cremastogyne Monitored by Antioxidant Enzymes

Lead (Pb) is a common toxic heavy metal element that can be absorbed by plant roots and enter the food chain, damaging human health. Alnus cremastogyne has a wide native range, is fast growing, has a wide range of timber uses, and has rhizomatous roots that can improve planted soils. In this study, we evaluated whether Alnus cremastogyne has the potential to remediate Pb-contaminated soils through a 6-month pot experiment in soils with different Pb concentrations (0, 50, 100, 200, and 400 mg/kg). Our results indicate that Alnus cremastogyne plant height, basal diameter, and organ biomass decreased, H2O2 and MDA content increased, and the activities of antioxidant enzymes and osmotic regulators increased and then decreased with increasing lead concentrations. The Pb bioconcentration factor of Alnus cremastogyne was less than 1 at all Pb concentrations, and Pb accumulated mainly in the root system. This indicates that Alnus cremastogyne is not a Pb-enriched plant and does not have outstanding Pb transport capacity. The growth of Alnus cremastogyne was not significantly affected at low Pb concentrations, and its plant height, basal diameter, and biomass were significantly suppressed under high Pb stress. Therefore, Alnus cremastogyne is not a suitable species for the remediation of lead-contaminated soils but can be used as a silvicultural species in environments with low lead levels.

Studies on the Nutritional, Minerals, Mineral Ratio, Anti-nutritional, Molar Ratio and Antioxidant Compositions of Four Selected Leafy Wild Vegetables in Ado-Ekiti, Ekiti State, Nigeria

The study investigated the nutritional, mineral Anti-nutritional factors, molar ratios and antioxidants compositions in the leaves of four selected wild edible vegetables (Piper guinensis, Piper umbelatum, Celosia argentia and Jatropha tajorensis) collected in Ado Ekiti, Ekiti State, Nigeria. The proximate, minerals and anti-nutrient compositions of the samples were determined using standard procedures. Also antioxidant activity of the samples were detected using standard assays such as 1, 1, diphenyl-2-2 picrylhydrazyl (DDPH) and Ferric Reducing Antioxidant Potential (FRAP).The mineral ratio, molar ratio and Mineral Safety Index were calculated from mineral results. The results of the proximate compositions for the four wild vegetables for moisture content, ash, crude fat, crude fiber, crude protein and carbohydrate ranged from 11.16 - 12.15%, 2.76-4.03%, 4.07 -7.31%, 13.33-16.73%, 7.36 – 10.09%, and 52.09 -58.22% respectively,. The results of the mineral composition revealed high content of K, moderate content of Ca, P, and low contents of Mg, Fe, Zn, Cu and very low concentrations of Pb and Ni. Cd was absent in all the samples investigated. Zn/Cu and Fe/Cu ratios indicated low copper load. Antinutrients factors in the vegetable were low with the exception of phytate which can be reduced to non-toxic level through boiling or cooking. The calculated mole ratio for [Phy][Zn], [Ca]/[Phy], [Phy]/[Fe] and [Ca][Phy]/[Zn] conformed with the standard values. The results of the antioxidant properties showed that the wild vegetables are good natural antioxidant sources. The assessment of the vegetables showed that they are rich sources of crude protein, crude fiber and carbohydrate with high energy calories. The mineral ratios and mineral safety index suggested that the minerals could not pose any mineral load to human body. Hence, the vegetables could be explored as supplement diet for man. The vegetables could provide the needed nutrition health benefit and also help in addressing the problem of food security in Nigeria.

LEAD LEVELS IN MILK AND ITS PRODUCTS FROM VARIOUS ENVIRONMENTS IN EGYPT

Milk and its products are considered healthy due to their content of key nutritional elements. Despite their essential role in the human diet, they may be susceptible to contamination with many chemical pollutants from the surrounding environment, most notably heavy metals such as lead, which is considered toxic to consumers. This study evaluated lead concentrations in milk and dairy product samples collected from various Egyptian environments. The results showed significant differences (p < 0.05) in Pb concentrations in the samples collected from different environments in Egypt (industrial, traffic and rural). The average lead content in raw cow’s milk, sterilised milk, Domiati cheese, Ras cheese, processed cheese and yoghurt samples from industrial areas were 2.23, 0.33, 3.19, 5.10, 0.11 and 0.09 mg/kg, respectively. In traffic areas, lead concentrations were 1.83, 0.30, 2.72, 4.72, 0.13 and 0.09, and in rural areas, they were 0.61, 0.27, 1.52, 3.13, 0.13 and 0.09. The data showed that Pb levels in dairy product samples collected from industrial areas are very high compared with those collected from traffic areas. By contrast, the lowest Pb concentrations were recorded in samples from rural areas. It is recommended that lead levels in different foods, especially milk and its products, be evaluated at regular intervals.

Group IV topological quantum alloy and the role of short-range order: the case of Ge-rich Ge1–xPbx

Despite the explosion of interest in topological materials over the last decades, their applications remain limited due to challenges in growth and incorporation with today’s microelectronics. As a potential bridge to close this gap, we investigate the group-IV alloy Ge1–xPbx, in the Ge-rich condition using density functional theory and show that relatively low concentrations of Pb (~9.4%) can lead to a topological phase transition. Furthermore, the calculation of the Z2 invariant for both the random alloy and the alloy with short-range order (SRO) indicate that the topological phase of the material can be directly modified by the degree of SRO. These findings are understood in terms of local structural relaxation, which decreases the bandgap in the random alloy. However, in the SRO case, the mutual avoidance of Pb leads to minimal structural relaxation, alleviating strain. Our findings not only highlight the emerging importance of SRO in alloy properties but also indicate the possibility of constructing topological interfaces between materials of identical composition (and nominally identical structure). Moreover, they uncover a viable avenue toward the monolithic integration of quantum materials with today’s semiconductor industry.

Sequestration of Pb(II) using channel-like porous spheres of carboxylated graphene oxide-incorporated cellulose acetate@iminodiacetic acid: optimization and mechanism study

The adsorption property of the costless green cellulose acetate (CA) was boosted by the dual modifications: inner modification by incorporating carboxylated graphene oxide (COOH-GO) into the CA spheres and outer modification by the surface modification of the COOH-GO@CA spheres by iminodiacetic acid (IDA) for removing Pb(II). The adsorption experiments of the Pb(II) proceeded in a batch mode to evaluate the adsorption property of the COOH-GO@CA@IDA spheres. The maximal Pb(II) adsorption capacity attained 613.30 mg/g within 90 min at pH = 5. The removal of Pb(II) reached its equilibrium within 20 min, and the removal % was almost 100% after 30 min at the low Pb(II) concentration. The Pb(II) adsorption mechanism was proposed according to the kinetics and isotherms studies; in addition, the zeta potential (ZP) measurements and X-ray Photoelectron Spectroscopy (XPS) analysis defined the adsorption pathways. By comparing the XPS spectra of the authentic and used COOH-GO@CA@IDA, it was deduced that the contributed chemical adsorption pathways are Lewis acid–base, precipitation, and complexation. The zeta potential (ZP) measurements demonstrated the electrostatic interaction participation in adsorbing the cationic Pb(II) species onto the negatively charged spheres (ZP = 14.2 mV at pH = 5). The unique channel-like pores of the COOH-GO@CA@IDA spheres suggested the pore-filling mechanism of Pb(II). The promising adsorption results and the superb recyclability character of COOH-GO@CA@IDA enable it to extend of the bench scale to the industrial scale.

Exposure to Sublethal Concentrations of Lead (Pb) Affects Ecologically Relevant Behaviors in House Sparrows (Passer domesticus)

Global contamination of environments with lead (Pb) poses threats to many ecosystems and populations. While exposure to Pb is toxic at high concentrations, recent literature has shown that lower concentrations can also cause sublethal, deleterious effects. However, there remains relatively little causal investigation of how exposure to lower concentrations of environmental Pb affects ecologically important behaviors. Behaviors often represent first-line responses of an organism and its internal physiological, molecular, and genetic responses to a changing environment. Hence, better understanding how behaviors are influenced by pollutants such as Pb generates crucial information on how species are coping with the effects of pollution more broadly. To better understand the effects of sublethal Pb on behavior, we chronically exposed adult wild-caught, captive house sparrows (Passer domesticus) to Pb-exposed drinking water and quantified a suite of behavioral outcomes: takeoff flight performance, activity in a novel environment, and in-hand struggling and breathing rate while being handled by an experimenter. Compared to controls (un-exposed drinking water), sparrows exposed to environmentally relevant concentrations of Pb exhibited decreases in takeoff flight performance and reduced movements in a novel environment following 9–10 weeks of exposure. We interpret this suite of results to be consistent with Pb influencing fundamental neuro-muscular abilities, making it more difficult for exposed birds to mount faster movements and activities. It is likely that suppression of takeoff flight and reduced movements would increase the predation risk of similar birds in the wild; hence, we also conclude that the effects we observed could influence fitness outcomes for individuals and populations altering ecological interactions within more naturalistic settings.

Water Quality and Risk Assessment of Selected Heavy Metals in Tilapia Oreochromis niloticus from Pulangi Lake, the Philippines

Regular monitoring of the water quality and heavy metal concentration in edible fish from the Pulangi Lake – an artificial lake in Bukidnon, the Philippines – has not yet been established. This study analyzed the water quality of the Pulangi Lake and assessed the associated risks of heavy metals cadmium (Cd), chromium (Cr), and lead (Pb) in Nile tilapia (Oreochromis niloticus) harvested from the lake during the dry season. Key informant interviews (KII) were also conducted to gather relevant information about the lake. The physico-chemical analysis of the surface water revealed high fecal coliform levels, exceeding the standard limit by more than 100%, but the concentrations of Cd, Cr, and Pb were below the standard limit. However, the Cr concentration in tilapia (0.2430–1.7870 mg/kg) exceeded the permissible limit of 0.05 mg/kg set by the Food and Agriculture Organization and the World Health Organization. Low concentrations of Cd (0.0270–0.1140 mg/kg) and Pb (0.0360–0.4350 mg/kg) were observed. The risk assessment of these individual heavy metals measured from tilapia and its combined impacts showed no potential non-carcinogenic effects based on the estimated target hazard quotient (THQ < 1) and hazard index (HI < 1). However, based on the permissible target cancer risk (1 x 10–6 to 1 x 10–4), tilapia from the Pulangi Lake should be reexamined as it appears that – in terms of Cd and Cr – the probability relating to contamination problem can occur. The present study can be used as baseline data for risk management.

Potential of organic wastes typical of the Brazilian Amazon for fertilizer use in agriculture

Characterization of different organic wastes is essential to reveal alternative nutrient sources useful for agriculture. The objective of this work was to characterize a variety of organic wastes generated in the Brazilian Amazon in order to identify nutrient sources for potential use as organic fertilizers. Samples of nine different organic wastes from agricultural, livestock and forestry activities were collected in the state of Pará, Amazon region, Brazil. These samples were characterized using reference methods for analyses of organic fertilizers. Palm oil mill boiler ash was highly concentrated in P, K, Ca, and Mg and also highly alkaline, being considered a promising material for use as fertilizer and lime in acid soils. Palm oil mill decanter cake was the best N source; it also contained relevant amounts of K, S, and Zn. Cattle manure was more concentrated in N and oil palm empty fruit bunch in K. Residual eucalyptus charcoal was high in Ca but also in Na and Al. Oil palm fruit fiber, oil palm fruit shell, wood sawdust of the pile top, and wood sawdust of the pile slope were consistently poor in nutrients. All wastes presented low concentrations of As, Ba, Cd, Cr, Hg, Pb, and Se. This study identified organic wastes differing in prevalent nutrients for potential use as organic fertilizers. Such a difference could be explored in further studies by combining two or more wastes with complementary prevalent nutrients in order to better meet the nutritional requirements of different crops in the Brazilian Amazon.

PROLIFERATION OF THE DIATOM CYCLOTELLA MENEGHINIANA AFFECTED BY EXPOSURE TO LEAD

Elevated levels of pollutants, including heavy metals, resulting from human activities, have raised concerns regarding their adverse impacts on natural ecosystems. Among these, aquatic organisms, particularly non-target microalgae, bear substantial consequences from such contaminants. This study endeavored to evaluate the impact of the heavy metal lead (Pb) at concentrations of 2.5, 25, and 250 μg L−1 on the growth and lipid content of the diatom Cyclotella meneghiniana in a 14-day toxicity test conducted under controlled laboratory conditions. The findings indicate that lower Pb concentrations (2.5 and 25 μg L−1 ) fostered algal proliferation, whereas exposure to 250 μg L−1 resulted in complete inhibition in two distinct endpoints. Additionally, no significant fluctuations in algal lipid content were discernible between exposure to 2.5 and 25 μg Pb L−1 and the control group. This study stands as a pioneering effort in unveiling the toxicity of Pb on C. meneghiniana, shedding light on the species’ susceptibility to this heavy metal and underscoring the necessity of incorporating this species into ongoing ecological risk assessments of Pb.

Adaptation to lead in a Pb/Zn-mine population of Marrubium cuneatum

Marrubium cuneatum is an endemic Iranian plant species, which can be found in lead-contaminated environments. This study aimed to investigate the effects of lead on the growth and germination in two M. cuneatum populations, from metalliferous, Pb-contaminated and uncontaminated soil, respectively. Soil and plant samples of the Tang-e Douzan Pb-Zn mine and Morghab Spring (non-contaminated site) were collected and analysed. Germination and growth were recorded under increasing Pb exposure in the non-metallicolous (NM) and the metallicolous (M) local M. cuneatum populations. Germination percentage (GP), mean germination time (MGT), germination index (GI), healthy plant percentage (HPP), seedling death (SD), fresh weight (FW) and dry weight (DW), were measured. Primary assessments showed toxic levels of lead in soil samples of the Tang-e Douzan mine and in leaves of plants growing at the mine site. Germination experiments showed that the germination parameters were stimulated by low concentrations of Pb in both populations, but inhibited by high concentrations. However, the adverse effects of Pb at high concentrations on GP, GI, and HPP were significantly less in the M population. The mortality of germinating seeds (SD) was consistently associated with fungal infection, which gradually decreased with increasing Pb exposure, but to the same degree in both populations. Growth experiments clearly demonstrated Pb hypertolerance in the M population. In the NM population, seedling growth is more sensitive to excess Pb than seed germination, compared to the M population. The M population has high biomass and a relatively high Pb accumulation in its shoots, which suggests it is a suitable candidate for phyto-extraction of Pb.

Banglaponics: A Soilless Cultivation Technique For Tomato In Bangladesh

The study was carried out to develop an efficient, reproducible method to overcome the drought stress and increasing agriculture field crisis of Bangladesh. Banglaponics, a soilless cultivation technique comprised of traditional agricultural fertilizers in pond water mixed with cow urine has been used to evaluate the efficiency of tomato production. The production rate (237.85 ± 10.87 g/plant) was significantly (p < 0.05) higher in the Banglaponics medium than soil medium. Plant height, leaf number, leaf area, root number, root length, and flower number of the studied plant showed significantly (p < 0.05) higher in Banglaponics medium than plants grown in soil. Both treatments showed that chlorophyll score and antioxidant activity (DPPH) were almost equal. Banglaponically grown plant leaf, despite having lower Ca concentrations, possessed higher concentrations of Fe and Zn than those of soil-grown. Additionally, Banglaponically grown plant also showed significantly much lower Pb concentrations than that of grown in soil. On the contrary the other two heavy metals Cr and Cd, hold nearly the same value. By appearance, Banglaponically-grown plants were much healthier than that of soil-grown. This technique can be introduced in drought-prone areas of Bangladesh as it requires much less water than soil-grown tomato plants. Bangladesh J. Bot. 52(4): 933-939, 2023 (December)

Estimation of Trace and Toxic Metals from Cannabis Sativa Plant in District, Kech Baluchistan, Pakistan

Background: Cannabis sativa, a plant indigenous to the Kech district in Baluchistan, Pakistan, is traditionally used for medicinal purposes. Understanding its trace and toxic metal content is crucial for evaluating its safety and therapeutic potential. Objective: The primary aim of this study is to estimate the levels of trace and toxic metals in various parts of Cannabis sativa plants grown in the Kech district and assess the potential health risks associated with their consumption. Methods: The leaves, stems, and roots of Cannabis sativa were analyzed for metals including Iron (Fe), Copper (Cu), Zinc (Zn), Potassium (K), Magnesium (Mg), Calcium (Ca), Sodium (Na), Cadmium (Cd), Lead (Pb), and Nickel (Co). Flame Atomic Absorption Spectroscopy was employed to quantify the metal content. Results: The plant exhibited high levels of Fe (20.34 ppm in leaves), Zn (24.14 ppm in leaves), Ca (9.29 ppm in leaves), Cu (14.40 ppm in leaves), K (10.56 ppm in leaves), Mg (13.47 ppm in leaves), and Na (12.25 ppm in leaves). Conversely, lower concentrations of Cd (0.65 ppm in leaves), Co (2.29 ppm in leaves), As (0.53 ppm in leaves), and Pb (1.60 ppm in leaves) were detected. The leaves contained higher concentrations of these metals compared to the stems and roots. Conclusion: The presence of beneficial trace metals like Fe, Cu, Zn, and Ca in significant amounts suggests Cannabis sativa's potential for treating diseases related to deficiencies of these metals. However, the low levels of toxic metals indicate minimal health risks, affirming its safety for medicinal use.

Detection of environmental pollutants from cobwebs found in selected lecture rooms at the Faculty of Science, Federal University Dutse, Nigeria

The aim of this study was to assess the environmental pollutants present in the cobwebs found in selected lecture rooms; Mathematics lecture room (MTH), Chemistry lecture room (CHM), Biology lecture room (BIO) and Environmental Science lecture room (EMT) in the Faculty of Science, Federal University Dutse. Bacterial pollutants coupled with Arsenic (As) Lead (Pb) in the sampled cobwebs were isolated and identified using standard procedures. One-way Analysis of variance was used to determine the variation in the concentrations of Pb and As in the sampled cobwebs. Staphylococcus aureus (28.1%), Bacillus sp. (37.5%), Streptococcus sp. (18.8%), and Streptobacillus sp. (15.6%) were detected in all the cobwebs samples. MTH 4 had the highest Pb concentration (1.2800 mg/kg) while CHM 3 had the lowest (0.470 mg/kg) Pb concentration. CHM 3 and BIO 3 had very low concentrations of Pb, which were significantly different from each other (p˂0.05). This study has revealed that spider cobwebs can be an effective bio-indicator in determining indoor air quality. Keywords: Indoor air, Cobwebs, Lecture rooms, Bacterial contaminants, Lead, Arsenic

Allanite geochronology in the Mount Isa Inlier

New allanite geochronology is presented for four mineral deposits in the Mount Isa Inlier (SWAN, Mary Kathleen, Koppany and Elaine Dorothy). The data indicate the occurrence of multiple phases of allanite formation: one at 1732 ± 8 Ma at Koppany, one at ca 1520 Ma at Mary Kathleen, Koppany and SWAN, and one at ca 1473 Ma at Mary Kathleen and Elaine Dorothy associated with vein calcite. In the Mary Kathleen–Koppany–Elaine Dorothy skarn system, there are chemical and textural differences between the three allanite generations; the ca 1520 Ma generation formed by dissolution–reprecipitation of 1732 Ma allanite, with no addition of externally sourced rare earth elements, as shown by the identical Nd isotopic compositions of these two populations. Allanite at SWAN yielded a 207Pb/206Pb ID-TIMS age of 1519.6 ± 1.1 Ma; its homogeneity, low common Pb contents and near-concordance make it a suitable reference material. Repeated remobilisation of rare earth elements in the Mary Kathleen system is surprising, given the widely accepted low solubility of these elements, but may have been restricted in spatial extent.