Arsenic modifies the effect of folic acid in spina bifida prevention, a large hospital-based case-control study in Bangladesh.

BACKGROUND: Spina bifida, a developmental malformation of the spinal cord, is associated with high rates of mortality and disability. Although folic acid-based preventive strategies have been successful in reducing rates of spina bifida, some areas continue to be at higher risk because of chemical exposures. Bangladesh has high arsenic exposures through contaminated drinking water and high rates of spina bifida. This study examines the relationships between mother's arsenic exposure, folic acid, and spina bifida risk in Bangladesh. METHODS: We conducted a hospital-based case-control study at the National Institute of Neurosciences & Hospital (NINS&H) in Dhaka, Bangladesh, between December 2016 and December 2022. Cases were infants under age one year with spina bifida and further classified by a neurosurgeon and imaging. Controls were drawn from children seen at NINS&H and nearby Dhaka Shishu Hospital. Mothers reported folic acid use during pregnancy, and we assessed folate status with serum assays. Arsenic exposure was estimated in drinking water using graphite furnace atomic absorption spectrophotometry (GF-AAS) and in toenails using inductively coupled plasma mass spectrometry (ICP-MS). We used logistic regression to examine the associations between arsenic and spina bifida. We used stratified models to examine the associations between folic acid and spina bifida at different levels of arsenic exposure. RESULTS: We evaluated data from 294 cases of spina bifida and 163 controls. We did not find a main effect of mother's arsenic exposure on spina bifida risk. However, in stratified analyses, folic acid use was associated with lower odds of spina bifida (adjusted odds ratio [OR]: 0.50, 95% confidence interval [CI]: 0.25-1.00, p = 0.05) among women with toenail arsenic concentrations below the median value of 0.46 µg/g, and no association was seen among mothers with toenail arsenic concentrations higher than 0.46 µg/g (adjusted OR: 1.09, 95% CI: 0.52-2.29, p = 0.82). CONCLUSIONS: Mother's arsenic exposure modified the protective association of folic acid with spina bifida. Increased surveillance and additional preventive strategies, such as folic acid fortification and reduction of arsenic, are needed in areas of high arsenic exposure.

Dynamic performance of combined biochar from co-pyrolysis of pig manure with invasive weed: Effect of natural aging on Pb and As mobilization in polluted mining soil.

Due to the natural biochar aging, the improvement of soil quality and immobilization of soil pollutants achieved by biochar may change; understanding the dynamic evolution of the in situ performance of biochar in these roles is essential to discuss the long-term sustainability of biochar remediation. Therefore, in this study, combined biochar from co-pyrolysis of pig manure and invasive Japanese knotweed - P1J1, as well as pure pig manure - PM - and pure Japanese knotweed - JK - derived biochar were applied to investigate their remediation performance in a high As- and Pb-polluted soil with prolonged incubation periods (up to 360 days). Biochar application, especially P1J1 and PM, initially promoted soil pH, dissolved organic carbon, and EC, but the improvements were not constant through time. The JK-treated soil exhibited the highest increase of soil organic matter (OM), followed by P1J1 and then PM, and OM did not change with aging. Biochar, especially P1J1, was a comprehensive nutrient source of Ca, K, Mg, and P to improve soil fertility. However, while soluble cationic Ca, K, and Mg increased with time, anionic P decreased over time, indicating that continuous P availability might not be guaranteed with the aging process. The total microorganism content declined with time; adding biochars slowed down this tendency, which was more remarkable at the later incubation stage. Biochar significantly impeded soil Pb mobility but mobilized soil As, especially in PM- and P1J1-treated soils. However, mobilized As gradually re-fixed in the long run; meanwhile, the excellent Pb immobilization achieved by biochars was slightly reduced with time. The findings of this study offer fresh insights into the alterations in metal(loid)s mobility over an extended duration, suggesting that the potential mobilization risk of As is reduced while Pb mobility slightly increases over time.

Influence of Pteris vittata-maize intercropping on plant agronomic parameters and soil arsenic remediation.

To achieve "production while remediation" in arsenic (As) -contaminated farmlands, a field experiment was conducted to investigate the effects of five Pteris vittata L. (PV) - maize intercropping modes on the growth, nutrient, and As accumulation characteristics of PV and maize. The intercropping increased the As content of PV by 2.9%-132.0% and decreased the As content in maize shoots by 15.5%-37.0%. Total As accumulation in above-ground plant parts reached 202.03-941.97 g hm-2. Intercropping also improved nitrogen and phosphorus content in maize kernels by 27.6%-124.7% and 15.9%-31.5%, respectively. Additionally, intercropping increased maize kernel 100-grain weight by 10.0%-16.6% and resulted in a 1.1%-24.1% increase in maize yield compared to sole cultivation. The intercropping transformed soil As from iron-bound to calcium-bound and aluminum-bound forms. Analysis of soil microbial diversity showed that the intercropping decreases the abundance of Chloroflexi and increases the abundance of Proteobacteria. Among the five modes, the intercropping mode with 4 rows of maize and 4 rows of PV showed the highest remediation efficiency and mechanized operation. These findings contribute to a theoretical framework and technical support for the simultaneous soil pollution remediation and productive farming practices.

Arsenic and fluoride in groundwater triggering a high risk: Probabilistic results using Monte Carlo simulation and species sensitivity distribution.

The widespread presence of arsenic (As) and fluoride (F-) in groundwater poses substantial risks to human health on a global scale. These elements have been identified as the most prevalent geogenic contaminants in groundwater in northern Mexico. Consequently, this study aimed to evaluate the human health and ecological risks associated with the content of As and F- in the Meoqui-Delicias aquifer, which is in one of Mexico's most emblematic irrigation districts. Concentrations of As and F- were measured in 38 groundwater samples using ICP-MS and ion chromatography, respectively. Overall, these elements showed a similar trend across the aquifer, revealing a positive correlation between them and pH. The concentration of As and F- in the groundwater ranged from 5.3 µg/L to 303 µg/L and from 0.5 mg/L to 8.8 mg/L, respectively. Additionally, the levels of As and F- surpassed the established national standards for safe drinking water in 92% and 97% of samples, respectively. Given that groundwater is used for both agricultural purposes and human activities, this study also assessed the associated human health and ecological risks posed by these elements using Monte Carlo simulation and Species Sensitivity Distribution. The findings disclosed a significant noncarcinogenic health risk associated with exposure to As and F-, as well as an unacceptable carcinogenic health risk to As through water consumption for both adults and children. Furthermore, a high ecological risk to aquatic species was identified for F- and high to medium risks for As in the sampling sites. Therefore, the findings in this study provide valuable information for Mexican authorities and international organizations (e.g., WHO) about the adverse effects that any exposure without treatment to groundwater from this region represents for human health.

Investigation of arsenic contamination in soil and plants along the river of Xinzhou abandoned gold mine in Qingyuan, China.

The exploitation of mineral resources is very important for economic development, but disorderly exploitation poses a serious threat to the ecological environment. However, investigations on the advantages of plant species and environmental pollution in polluted mining areas are limited. Thus, a survey was conducted to evaluate the impacts of abandoned mines on the surrounding ecological environment along rivers in polluted areas and to determine the Arsenic (As) pollution status in soil and plants. The results showed that the soil and vegetation along the river in the survey area were seriously polluted by As. The total As content of the 15 samples was significantly greater than the national soil background value (GB 15618-2018), and degree of pollution was nonlinearly related to the distance from the mine source, R2 = 0.9844. B. bipinnata, P. vittata and B. nivea were predominant with degrees of dominance of 0.01-0.33, 0.05-0.11, and 0.06-0.14 respectively. The As enrichment capacities of Juncus and P. vittata were significantly greater than those of the other plants, while the bioaccumulation factors (BCFs) were 21.81 and 7.04, respectively.

Colloidal fraction on pomelo peel-derived biochar plays a dual role as electron shuttle and adsorbent in controlling arsenic transformation in anoxic paddy soil.

Arsenic release and reduction in anoxic environments can be mitigated or facilitated by biochar amendment. However, the key fractions in biochars and how they control arsenic transformation remain poorly understood. In this study, a biochar produced from pomelo peel was rich in colloids and was used to evaluate the roles of the colloidal and residual fractions of biochar in arsenic transformation in anoxic paddy soil. Bulk biochar showed a markedly higher maximum adsorption capacity for As(III) at 1732 mg/kg than for As(V) at 75.7 mg/kg, mainly because of the colloidal fraction on the surface. When compared with the control and treatments with the colloidal/residual fraction, the addition of bulk biochar facilitated As(V) reduction and release in the soil during days 0-12, but decreased the dissolved As(III) concentration during days 12-20. The colloidal fraction revealed significantly higher electron donating capacity (8.26 µmole-/g) than that of bulk biochar (0.88 µmole-/g) and residual fraction (0.65 µmole-/g), acting as electron shuttle to promote As(V) reduction. Because the colloidal fraction was rich in aliphatic carbon, fulvic acid-like compounds, potassium, and calcium, it favored As(III) adsorption when more As(III) was released, probably via organic-cation-As(III) complexation. These findings provide deeper insight into the role of the colloidal fraction of biochar in controlling anaerobic arsenic transformation, which will be helpful for the practical application of biochar in arsenic-contaminated environments.

Arsenic and cadmium availability and its removal in paddy farming areas.

Arsenic (As) and cadmium (Cd) accumulation in rice grain is a global concern threatening food security and safety to the growing population. As and Cd are toxic non-essential elements poisonous to animal and human at higher levels. Its accumulation in agro-ecosystems pose a public health risk to consumers of agro-ecosystem products. Due to their hazards, As and Cd sources should be cleared, avoiding entering plants and the human body. As and Cd removal in soils and grains in agro-ecosystems has been conducted by various materials (natural and synthesized), however, there are little documentation on their contribution on As and Cd removal or reduction in rice grains. This identified knowledge gap necessitate a systematically review to understand efficiency and mechanisms of As and Cd availability reduction and removal in paddy farming areas through utilization of various synthetic and modified materials. To achieve this, published peer reviewed articles between 2010 and 2024 were collected from various database i.e., Science Direct, Web of Science, Google Scholar, and Research Gate and analyzed its content in respect to As and Cd reduction and removal. Furthermore, collected data were re-analyzed to determine standardized mean differences (SMD) with 95% confidence intervals (CI). Based on 96 studies with 228 observations involving Fe, Ca, Si, and Se-based materials were identified, it was found that application of Fe, Ca, Si, and Se-based materials potentially reduced As and Cd in rice grains among various study sites and across studies. Among the studied materials, Fe-based materials observed to be more efficient compared to other utilized materials. However, there little or no information on performance of materials when used in combination and how they can improve crop productivity and soil health, thus requiring further studies. Thus, this study confirm Fe, Ca, Si, and Se modified materials have significant potential to reduce As and Cd availability in paddy farming areas and rice grains, thus necessary effort must be made to ensure materials access and availability for farmers utilization in paddy fields to reduce As and Cd accumulation.

Evaluation of arsenic pollution in field-contaminated soil at the soil's actual pH.

The pollution and ecological risks posed by arsenic (As) entering the soil are the major environmental challenges faced by human beings. Soil phosphatase can serve as a useful indicator for assessing As contamination under specific soil pH conditions. However, the study of phosphatase kinetics in long-term field As-contaminated soil remains unclear, presenting a significant obstacle to the monitoring and evaluation of As pollution and toxicity. The purpose of this study was to determine phosphatase activity and explore enzyme kinetics in soils subjected to long-term field As contamination. Results revealed that the soil phosphatase activity varied among the tested soil samples, depending on the concentrations of As. The relationship between total As, As fractions and phosphatase activity was found to be significant through negative exponential function fitting. Kinetic parameters, including maximum reaction velocity (Vmax), Michaelis constant (Km) and catalytic efficiency (Vmax/Km), ranged from 3.14 × 10-2-53.88 × 10-2 mmol/(L·hr), 0.61-7.92 mmol/L, and 0.46 × 10-2-11.20 × 10-2 hr-1, respectively. Vmax and Vmax/Km of phosphatase decreased with increasing As pollution, while Km was less affected. Interestingly, Vmax/Km showed a significant negative correlation with all As fractions and total As. The ecological doses (ED10) for the complete inhibition and partial inhibition models ranged from 0.22-70.33 mg/kg and 0.001-55.27 mg/kg, respectively, indicating that Vmax/Km can be used as an index for assessing As pollution in field-contaminated soil. This study demonstrated that the phosphatase kinetics parameters in the soil's pH system were better indicators than the optimal pH for evaluating the field ecotoxicity of As.

Evaluation and health risk assessment of arsenic and potentially toxic elements pollution in groundwater of Majha Belt, Punjab, India.

Concentrations of potentially toxic elements (PTEs) like arsenic, uranium, iron, and nitrate in the groundwater of the Majha Belt (including Tarn Taran, Amritsar, Gurdaspur, and Pathankot districts) in Punjab, India were measured to evaluate the health risks associated with its consumption and daily use. The average concentrations of these elements in some locations exceeded the WHO-recommended values. Arsenic and iron toxicity levels were found to be higher in the Amritsar district, while uranium toxicity was more prevalent in Tarn Taran. The Trace Element Evaluation Index suggests that Amritsar is one of the districts most affected by toxic elements. According to the US Environmental Protection Agency's (USEPA) guidelines, the HQ values of U, Fe, and nitrate were less than one, indicating that there is no non-carcinogenic health risk for adults and children. However, the hazard quotient (HQ) value for arsenic was greater than one, indicating a higher possibility of health risk due to arsenic in the study area. The total hazard index values of 44.10% of samples were greater than four for arsenic, indicating that people in the Majha Belt are at a very high health risk due to the usage of water for drinking and domestic purposes. The cancer risk assessment values for arsenic in children (5.69E + 0) and adults (4.07E + 0) were higher than the accepted limit of USEPA (10-4 to 10-6) in the Majha Belt. The average radiological cancer risk values of U for children and adults were 8.68E-07 and 9.45E-06, respectively, which are well below the permissible limit of 1.67 × 10-4 suggested by the Atomic Energy Regulatory Board of DAE, India. The results of this study confirm that the residents of the Majha Belt who use contaminated groundwater are at a serious risk of exposure to arsenic in the Amritsar district and uranium in Tarn Taran district.

Integrated Approach to Hydrogeochemical Assessment of Groundwater Quality in Major Industrial Zone of Punjab, Pakistan.

Groundwater contamination with arsenic (As) is a significant concern in Pakistan's Punjab Province. This study analyzed 69 groundwater samples from Faisalabad, Gujranwala, Lahore, and Multan to understand hydrogeochemistry, health impacts, contamination sources, and drinking suitability. Results revealed varying as concentrations across districts, with distinctive cation and anion orders. Faisalabad exhibited Na+ > Mg2+ > Ca2+ > K+ > Fe2+ for cations and SO42- > Cl- > HCO3- > NO3- > F- for anions. Gujranwala showed Na+ > Ca2+ > Mg2+ > K+ for cations and HCO3- > SO42- > Cl- > NO3- > F- for anions. In Lahore, demonstrated: Na+ > Ca2+ > Mg2+ > Fe > K+ for cations and HCO3- > SO42- > Cl- > NO3- > F- for anions. Multan indicated K+ > Ca2+ > Mg2+ > Na+ > Fe for cations and HCO3- > SO42- > Cl- > F- > NO3- ) for anions. Hydrochemical facies were identified as CaHCO3 and CaMgCl types. Principal Component Analysis (PCA), highlighted the influence of natural processes and human activities on groundwater pollution. Water Quality Index (WQI) result reveal that most samples met water quality standards. The carcinogenic risk values for children exceeded permissible limits in all districts, emphasizing a significant cancer risk. The study highlights the need for rigorous monitoring to mitigate (As) contamination and protect public health from associated hazards.

Sea-level rise and arsenic-rich soils: A toxic relationship.

In the United States, dangerously high arsenic (As) levels have been found in drinking water wells in more than 25 states, potentially exposing 2.1 million people to drinking water high in As; a known carcinogen. The anticipated sea-level rise (SLR) is expected to alter soil biogeochemical and hydrological conditions, potentially impacting their ability to sequester As. In our study of coastal Wilmington, DE, an area projected to experience a 1 -meter SLR by 2100, we examined the spatial distribution, speciation, and release possibilities of As due to SLR. To understand the complex dynamics at play, we employed a comprehensive approach, including bulk and micro X-ray absorption spectroscopy measurements, hydrological pattern evaluation, and macroscopic stirred-flow experiments. Our results suggest that introducing reducing and saline conditions can increase As release in both river water and seawater inundation scenarios, most likely due to ionic competition and the dissolution of As-bearing Fe/Mn oxides. Regardless of the salinity source, the released As concentrations consistently exceeded the EPA threshold for drinking water. Our results provide valuable insights for developing appropriate remedial and management strategies for this site and numerous others facing similar environmental challenges. ENVIRONMENTAL IMPLICATION: With nearly two hundred million individuals living within coastal flood plains and with two million square kilometers of land and one trillion dollars' worth of assets lying less than 1 m above current sea level, sea-level rise (SLR) is one of the significant socio-economic threats associated with global warming. Arsenic is a prevalent contaminant in coastal areas impacted by industrial activities, many of which are susceptible to being impacted by SLR. This study examines SLR's impact on arsenic fate and speciation in a densely populated coastline in Wilmington, DE, expecting 1 meter of SLR by 2100.

Sources and human health risks associated with potentially toxic elements (PTEs) in urban dust: A global perspective.

Long-term exposure to urban dust containing potentially toxic elements (PTEs) poses detrimental impacts on human health. However, studies estimating human health risks in urban dusts from a global perspective are scarce. We evaluated data for twelve PTEs in urban dusts across 59 countries from 463 published articles, including their concentrations, input sources, and probabilistic risks to human health. We found that 34.1 and 60.3% of those investigated urban dusts have been heavily contaminated with As and Cd, respectively. The input of PTEs was significantly correlated with economic structure due to emissions of industrial activities and traffic emissions being the major sources. Based on the Monte Carlo simulation, we found that the mean hazard index below the safe threshold (1.0) could still cause non-negligible risks to human health. Arsenic and Cr were the major PTEs threatening human health, and relatively high risk levels were observed in cities in China, Korea, Chile, Malaysia, and Australia. Importantly, our analysis suggested that PTEs threaten the health of approximately 92 million adults and 280 million children worldwide. Overall, our study provides important foundational understanding and guidance for policy decision-making to reduce the potential risks associated with PTE exposure and to promote sustainable development of urban economies.

Industrial hemp (Cannabis sativa L.) can utilize and remediate soil strongly contaminated with Cu, As, Cd, and Pb by phytoattenuation.

Industrial hemp (Cannabis sativa L.) has great application potential in heavy metal-polluted soils owing to its safe non-food utilization. However, the fate of heavy metals in different varieties of hemp planted in strongly contaminated natural soils remains unknown. Here, we investigated the growth, heavy metal uptake, distribution, and transfer of nine hemp varieties in soils strongly contaminated with Cu, As, Cd, and Pb. Hemp variety and metal type were the main factors affecting the growth and heavy metal uptake in hemp. The nine hemp varieties grew well in the contaminated soils; however, differences existed among the varieties. The biomass of Z3 reached 5669.1 kg hm-1, whereas that of Yunma No. 1 was only 51.8 % of Z3. The plant height, stalk diameter, and stalk bark thickness of Z3 were greater than those of the other varieties, reaching 168 cm, 9.2 mm, and 0.56 mm, respectively. Permanova's analysis revealed that the total effects of Cu, As, Cd, and Pb on the growth of the nine hemp varieties reached 60 %, with leaf As having the greatest effect, reaching 16 %. , Even in strongly contaminated soils, the nine varieties showed poor Cu, As, Cd, and Pb uptake. Most of the Cu, As, Cd, and Pb were retained in the root, reaching 57.7-72.4, 47.6-64.7, 76.0-92.9, and 70.0-87.8 %, respectively. Overall, the Cu, As, Cd, and Pb uptake of Wanma No.1 was the highest among the nine varieties, whereas that of Guangxi Bama was the lowest. These results indicate that hemp is a viable alternative for phytoattenuation in soils contaminated with heavy metals because of its ability to tolerate and accumulate Cu, As, Cd, and Pb in its roots, and Guangxi Bama is superior to the other varieties considering the safe utilization of hemp products.

Bioaccessibility and human health risks of arsenic from geological origin in lateritic red soil on construction land.

Current human health risk assessments of soil arsenic (As) contamination rarely consider bioaccessibility (IVBA), which may overestimate the health risks of soil As. The IVBA of As (As-IVBA) may differ among various soil types. This investigation of As-IVBA focused As from geological origin in a typical subtropical soil, lateritic red soil, and its risk control values. The study used the SBRC gastric phase in vitro digestion method and As speciation sequential extraction based upon phosphorus speciation extraction method. Two construction land sites (CH and HD sites) in the Pearl River Delta region were surveyed. The results revealed a high content of residual As (including scorodite, mansfieldite, orpiment, realgar, and aluminum arsenite) in the lateritic red soils at both sites (CH: 84.9%, HD: 91.7%). The content of adsorbed aluminum arsenate (CH: 3.24%, HD: 0.228%), adsorbed ferrum arsenate (CH: 8.55%, HD: 5.01%), and calcium arsenate (CH: 7.33%, HD: 3.01%) were found to be low. The bioaccessible As content was significantly positively correlated with the As content in adsorbed aluminum arsenate, adsorbed ferrum arsenate, and calcium arsenate. A small portion of these sequential extractable As speciation could be absorbed by the human body (CH: 14.9%, HD: 3.16%), posing a certain health risk. Adsorbed aluminum arsenate had the highest IVBA, followed by calcium arsenate, and adsorbed ferrum arsenate had the lowest IVBA. The aforementioned speciation characteristics of As from geological origin in lateritic red soil contributed to its lower IVBA compared to other soils. The oxidation state of As did not significantly affect As-IVBA. Based on As-IVBA, the carcinogenic and non-carcinogenic risks of soil As in the CH and HD sites decreased greatly in human health risk assessment. The results suggest that As-IVBA in lateritic red soil should be considered when assessing human health risks on construction land.

Does transplanted Posidonia oceanica act as a sink or source of trace elements? Ecological implications for restoring polluted coastal areas.

Despite the high potential of seagrass restoration to reverse the trend of marine ecosystem degradation, there are still many limitations, especially when ecosystems are severely degraded. In particular, it is not known whether restoring polluted ecosystems can lead to potentially harmful effects associated with contaminant remobilisation. Here, we aimed to investigate the role of P. oceanica transplanted from a pristine meadow to a polluted site (Augusta Bay, Italy, Mediterranean Sea) in two seasons of the year, as a sink or source of trace elements to the environment. The main results showed i) higher accumulation of chromium (Cr), copper (Cu) and total mercury (THg) in plants transplanted in summer than in winter, as well as an increase in Cr and THg in plants from sites with higher trace element loads; ii) an increase in leaf phenolics and a decrease in rhizome soluble carbohydrates associated with As and THg accumulation, suggesting the occurrence of defence strategies to cope with pollution stress; iii) a different partitioning of trace elements between below- and above-ground tissues, with arsenic (As) and Cr accumulating in roots, whereas Cu and THg in both roots and leaves. These results suggest that P. oceanica transplanted to polluted sites can act as both a sink and a source, sequestering trace elements in the below-ground tissues thus reducing their bioavailability, but also potentially remobilising them. However, the amount of trace elements potentially exported from P. oceanica to the environment through transfer into food webs via leaves and detritus appeared to be low under the specific conditions of the study site. Although further research into seagrass restoration of polluted sites would improve current knowledge to support effective ecosystem-based coastal management, the benefits of restoring polluted sites through seagrass transplantation appear to outweigh the potential costs of inaction over time.

Relation between solid phase speciation and oral/lung bioaccessibility of metal(loid)s polluted soils in inhabited area: Contribution of synchrotron-based experiment.

The presence of contaminated sites/soils in or near cities can pose significant risks to public health. The city of Viviez (France) was taken in reference site bears significant industrial responsibility, particularly in zinc metallurgy, with the presence of a now rehabilitated smelter. This has led to soil contamination by zinc (Zn), lead (Pb), arsenic (As), and cadmium (Cd), with concentrations reaching up to 4856 mg kg-1, 1739 mg kg-1, 195 mg kg-1, and 110 mg kg-1, respectively. The aim of this study is to comprehend the contamination patterns of the site post-rehabilitation, the geochemical behavior of each element, and their speciation (analyzed through BCR, XRD, and XANES) in relation to associated health risks due to metals accessibility for oral ingestion and inhalation by the local population. The findings revealed that elements inducing health risks were not necessarily those with the highest metal contents. All results are discussed in terms of the relationship between element speciation, stability of bearing phases, and their behavior in different media. XANES is an important tool to determine and estimate the Pb-bearing phases in garden soils, as well as the As speciation, which consist of Pb-goethite, anglesite, and Pb-humate, with variations in proportions (the main phases being 66 %, 12 % and 22 % for Pb-goethite, anglesite, and Pb-humate, respectively) whereas As-bearing phase are As(V)-rich ferrihydrite-like. A new aspect lies in the detailed characterization of solid phases before and after bioaccessibility tests, to qualify and quantify the bearing phases involved in the mobility of metallic elements to understand the bioaccessibility behavior. Ultimately, the health risk associated with exposure to inhabitants, in terms of particle ingestion and inhalation, was assessed. Only ingestion-related risk was deemed unacceptable due to the levels of As and Pb.

A thiazole-based colorimetric and photoluminescent chemosensors for As3+ ions detection: Density functional theory, test strips, real samples, and bioimaging applications.

A Schiff-base Ethyl (E)-2-(3-((2-carbamothioylhydrazono)methyl)-4-hydroxyphenyl)-4-methylthiazole-5-carboxylate (TZTS) dual functional colorimetric and photoluminescent chemosensor which includes thiazole and thiosemicarbazide has been synthesized to detect arsenic (As3+) ions selectively in DMSO: H2O (7:3, v/v) solvent system. The molecular structure of the probe was characterized via FT-IR, 1H, and 13C NMR & HRMS analysis. Interestingly, the probe exhibits a remarkable and specific colorimetric and photoluminescence response to As3+ ions when exposed to various metal cations. The absorption spectral changes of TZTS were observed upon the addition of As3+ ions, with a naked eye detectable color change from colorless to yellow color. Additionally, the chemosensor (TZTS) exhibited a new absorption band at 412 nm and emission enhancements in photoluminescence at 528 nm after adding As3+ ions. The limit of detection (LOD) for As3+ ions was calculated to be 16.5 and 7.19 × 10-9 M by the UV-visible and photoluminescent titration methods, respectively. The underlying mechanism and experimental observations have been comprehensively elucidated through techniques such as Job's plot, Benesi-Hildebrand studies, and density functional theory (DFT) calculations. For practical application, the efficient determination of As3+ ions were accomplished using a spike and recovery approach applied to real water samples. In addition, the developed probe was successfully employed in test strip applications, allowing for the naked-eye detection of arsenic ions. Moreover, fluorescence imaging experiments of As3+ ions in the breast cancer cell line (MCF-7) demonstrated their practical applications in biological systems. Consequently, these findings highlight the significant potential of the TZTS sensor for detecting As3+ ions in environmental analysis systems.

The effect of soil types, pH, and geographical locations on carcinogenic metal buildup in Oryza sativa cultivated in Ghana.

This study investigated the impact of soil type, pH, and geographical locations on the accumulation of arsenic (As), lead (Pb), and cadmium (Cd) in rice grains cultivated in Ghana. One hundred rice farms for the sampling of rice grains and soil were selected from two regions in Ghana-Volta and Oti. The concentrations of As, Pb, and Cd were analyzed using ICP-OES. Speciation modeling and multivariate statistics were employed to ascertain the relations among measured parameters. The results showed significant variations in soil-As, Pb, and Cd levels across different soil types and pH ranges, with the highest soil-As and Cd found in alkaline vertisols. For soil-As and Cd, the vertisols with a pH more than 7.0 exhibited the highest mean concentration of As (2.51 ± 0.932 mgkg-1) and Cd (1.00 ± 0.244 mgkg-1) whereas for soil-Pb, the luvisols of soil types with a pH less than 6.0 exhibited the highest mean concentration of Pb (4.91 ± 1.540 mgkg-1). Grain As, Pb, and Cd also varied across soil types and pH levels. In regards to grain-As, the vertisols soil type, with a pH less than 6.0, shows the highest mean concentration of grain As, at 0.238 ± 0.107 mgkg-1. Furthermore, vertisols soil types with a pH level less than 6.0 showed the highest mean concentration of grain Cd, averaging at 0.231 ± 0.068 mgkg-1 while luvisols, with a pH less than 6.0, exhibited the highest mean concentration of grain Pb at 0.713 ± 0.099 mgkg-1. Speciation modeling indicated increased bioavailability of grains Cd2+ and Pb2+ ions in acidic conditions. A significant interaction was found between soil-Cd and pH, affecting grain-As uptake. The average concentrations of soil As, Pb, and Cd aligned with international standards. Generally, the carcinogenic metals detected in grain samples collected from the Volta region are higher than that of the Oti region but the differences are insignificant, and this may be attributed to geographical differences and anthropogenic activities. About 51% of the study area showed a hazard risk associated with grain metal levels, although, no carcinogenic risks were recognized. This study highlights the complex soil-plant interactions governing metal bioaccumulation and emphasizes the need for tailored strategies to minimize metal transfer into grains.

Heavy metal association with chronic kidney disease of unknown cause in central India-results from a case-control study.

BACKGROUND: Chronic Kidney Disease of unknown cause (CKDu) a disease of exclusion, and remains unexplained in various parts of the world, including India. Previous studies have reported mixed findings about the role of heavy metals or agrochemicals in CKDu. These studies compared CKDu with healthy controls but lacked subjects with CKD as controls. The purpose of this study was to test the hypothesis whether heavy metals, i.e. Arsenic (As), Cadmium (Cd), Lead (Pb), and Chromium (Cr) are associated with CKDu, in central India. METHODS: The study was conducted in a case-control manner at a tertiary care hospital. CKDu cases (n = 60) were compared with CKD (n = 62) and healthy subjects (n = 54). Blood and urine levels of As, Cd, Pb, and Cr were measured by Inductively Coupled Plasma- Optical Emission Spectrometry. Pesticide use, painkillers, smoking, and alcohol addiction were also evaluated. The median blood and urine metal levels were compared among the groups by the Kruskal-Wallis rank sum test. RESULTS: CKDu had significantly higher pesticide and surface water usage as a source of drinking water. Blood As levels (median, IQR) were significantly higher in CKDu 91.97 (1.3-132.7) µg/L compared to CKD 4.5 (0.0-58.8) µg/L and healthy subjects 39.01 (4.8-67.4) µg/L (p < 0.001) On multinominal regression age and sex adjusted blood As was independently associated with CKDu[ OR 1.013 (95%CI 1.003-1.024) P < .05].Blood and urinary Cd, Pb, and Cr were higher in CKD compared to CKDu (p > .05). Urinary Cd, Pb and Cr were undetectable in healthy subjects and were significantly higher in CKDu and CKD compared to healthy subjects (P = < 0.001). There was a significant correlation of Cd, Pb and Cr in blood and urine with each other in CKDu and CKD subjects as compared to healthy subjects. Surface water use also associated with CKDu [OR 3.178 (95%CI 1.029-9.818) p < .05). CONCLUSION: The study showed an independent association of age and sex adjusted blood As with CKDu in this Indian cohort. Subjects with renal dysfunction (CKDu and CKD) were found to have significantly higher metal burden of Pb, Cd, As, and Cr as compared to healthy controls. CKDu subjects had significantly higher pesticide and surface water usage, which may be the source of differential As exposure in these subjects.

Essential and non-essential element concentrations in human milk samples and the assessment of infants' exposure.

As the data concerning element concentrations in human milk (HM) samples and their intake by infants are lacking in Poland, the present study aimed to explore this issue. The material consisted of HM samples obtained from 30 exclusively breastfeeding mothers during 4-6 weeks postpartum. Additionally, to identify the factors that may potentially affect HM composition, information regarding maternal data (anthropometry, body composition, and diet) was also collected. Maternal diet was assessed with two methods-a food frequency questionnaire and 3-day dietary records. In total, 18 essential and non-essential elements were determined. For the elements analysis, we used inductively coupled plasma quadrupole mass spectrometry. Most of the elements (n = 11, 61%) were detected in all HM samples. In all HM samples tin concentration was higher (5.67 ± 2.39 µg/L) than the usual range reported by the World Health Organization (~ 1.0 µg/L). HM cadmium content was positively associated with maternal salty snacks intake (r = 0.502, p = 0.005), arsenic with whole-grain products intake (r = 0.37, p = 0.043), and mercury concentration with fruits and seeds/nuts consumption (r = 0.424, p = 0.042 and r = 0.378, p = 0.039, respectively). Higher HM lead concentration was predicted by maternal age (95% CI [0.94-0.97]), intake of fish (95% CI [1.01-1.03]), and vegetables (95% CI [1.02-1.06]). The highest infants' intake was observed for copper (35.24 ± 12.48) and the lowest for arsenic (0.076 ± 0.102). Infants' exposure to lead was associated with maternal frequency consumption of canned fish (p = 0.0045). There is a need to perform further research on this topic to maximize the benefits of breastfeeding by minimizing maternal and infant exposure to potentially toxic elements.