Lead toxicity: a review

From waste to resource: LIBS methodology development for rapid quality assessment of recycled wood

Management and reuse of wood waste can be a challenging process due to the frequent presence of hazardous contaminants. Conventional detection methods are often limited by the need for excessive sample preparation and lengthy and expensive analysis. Laser-induced Breakdown Spectroscopy (LIBS) is a rapid and micro-destructive technique that can be a promising alternative, providing in-situ and real-time analysis, with minimal to no sample preparation required. In this study, LIBS imaging was used to analyze wood waste samples to determine the presence of contaminants such as As, Ba, Cd, Cr, Cu, Hg, Pb, Sb, and Ti. For this analysis, a methodology based on detecting three lines per element was developed, offering a screening method that can be easily adapted to perform qualitative analysis in industrial contexts with high throughput operations. For the LIBS experimental lines selection, control and reference samples, and a pilot set of 10 wood wastes were analysed. Results were validated by two different X-ray Fluorescence (XRF) systems, an imaging XRF and a handheld XRF, that provided spatial elemental information and spectral information, respectively. The results obtained highlighted LIBS ability to detect highly contaminated samples and the importance of using a 3-line criteria to mitigate spectral interferences and discard outliers. To increase the dataset, a LIBS large-scale study was performed using 100 samples. These results were only corroborated by the XRF-handheld system, as it provides a faster alternative. In particular cases, ICP-MS analysis was also performed. The success rates achieved, mostly above 88 %, confirm the capability of LIBS to perform this analysis, contributing to more sustainable waste management practices and facilitating the quick identification and remediation of contaminated materials.

Iron deficiency in pregnancy and its association with blood lead and manganese levels in offspring in Benin, Sub-Saharan Africa

INTRODUCTION

The impact of prenatal iron deficiency (ID) on offspring's blood lead level (BLL) and blood manganese level (BML) in infancy remains poorly understood. This study aimed to assess associations between prenatal ID and BLL/BML in offspring in Benin. We also investigated associations between infant ID and corresponding BLL and BML in infants.

MATERIALS AND METHODS

Data on hematological parameters, metal blood concentrations, and socioeconomic status were obtained from a prospective mother-child cohort study in Allada, Benin. Blood samples were collected during pregnancy (n = 501), at delivery (n = 501), and from 12-month-old infants (n = 501) to assess iron deficiency and haemoglobin concentration. Additionally, BML was analyzed for a subset of 12-month-old infants (n = 271), and BLL was determined for the full cohort of 12-month-old infants (n = 501). Associations between ID and metal concentrations were examined using logistic regressions.

RESULTS

Prenatal ID and IDA at the first and third antenatal care visit (ANC) were positively associated with infant BLL above 50 μg/L. Infants of mothers with prenatal ID and IDA had higher BLL. Moreover, prenatal ID and IDA at first and second ANC visits were positively associated with higher infant BML. In infancy, infants with ID and IDA had significantly higher BLL as compared to those without ID and IDA. Infant ID and IDA were positively associated with elevated BLL.

CONCLUSION

Elevated BLL and BML in infants were positively associated with ID and/or IDA prenatally during at least one ANC visit, while in infancy, infant ID and IDA were positively associated with elevated BLL only. Infants with ID and IDA showed higher BLL but not BML. This suggests that ID prenatally and during infancy may contribute to high blood lead concentrations in infants, which can lead to neurotoxicity. Treating ID and IDA is critical to prevent toxicity caused by high BLL in infants.

Neurological impact of sub-chronic lead acetate exposure on pain perception in mice

Lead exposure is a significant environmental health concern with potential impacts on pain perception and physiological functions. This study investigates the effects of sub-chronic lead acetate exposure on pain threshold, pain intensity, blood cortisol levels, and metabolic parameters in 24 adult male albino mice. The mice were randomly divided into three groups: a control group that received fresh water and two experimental groups that received drinking water containing lead acetate at concentrations of 5 ppm and 500 ppm over a twelve-week period. Pain perception was assessed using thermal (hot plate test) and chemical (formalin injection) pain models. Exposure to lead acetate resulted in a significant increase in the latency to thermal pain response, with delays of 52 % in the 5 ppm group and 59 % in the 500 ppm group (P < 0.05). Thermal pain intensity was reduced significantly by 63 % in the 5 ppm group and 82 % in the 500 ppm group (P < 0.05). However, changes in the onset time and intensity of chemical pain, as well as blood cortisol levels, were not statistically significant. Additionally, no significant differences in food and water intake or body weight changes were observed among the groups. These findings indicate that lead exposure can alter pain perception, with effects most pronounced in the context of thermal pain. Future research should explore lead's impact across different age groups and developmental stages, as well as its effects on specific neurotransmitter systems and receptor interactions. This research provides insights into the complex effects of lead on neurological function and highlights the importance of understanding lead's broader physiological impacts.

The role of the gut microbiome in the associations between lead exposure and child neurodevelopment

Lead is highly toxic to the developing brain. Given its persistence in the environment, new intervention strategies are needed to mitigate the impacts of lead on child neurodevelopment. The gut microbiome, referring to the bacteria and microorganisms residing in the gastrointestinal system, may be a viable target for intervention. This short review summarizes recent evidence linking the gut-brain axis to child developmental outcomes. We explore how lead-induced effects to the gut microbiome could indirectly affect child neurodevelopment, such that disrupting or offsetting this mediating process could buffer the effects of lead on child developmental outcomes. Unexpected findings with respect to child microbiota diversity and child cognitive and behavioral outcomes as well as lead exposure and adult microbiota diversity are discussed. When possible, we draw connections between observed changes to relative bacterial abundance, proposed bacterial functions, and downstream effects to brain development. We also explore how the gut microbiome might modify the toxicity of lead by impeding the uptake of lead across the gastrointestinal tract or through indirect mechanisms in such ways that the gut microbiome does not fit within a mediating pathway. In this case, promoting the buffering capacity of the gut microbiome may reduce the impacts of lead on child neurodevelopment. The goal of this short review is to bring attention to the potential role of the gut microbiome in the associations between lead exposure and child neurodevelopment with an eye towards intervention.

One night with Venus, a lifetime with mercury : Analyses of heavy metals in Franz Schubert's hair are consistent with syphilis treatment

Samples from three strands of Franz Schubert's hair, which are very likely to be authentic due to their well-documented origin and the chain of custody that is still valid today, were analyzed in terms of molecular biology and heavy metal content. The two hair samples presumably taken from the deceased's head showed matching molecular biological parameters, while the sample taken 35 years after his burial did not contain any usable DNA. Heavy metal analyses along the hair samples using LA-ICP-MS (laser ablation inductively coupled plasma mass spectrometry) with a temporal resolution of 4-5 h revealed significantly increased mercury and lead concentrations in all samples with a decreasing tendency towards the time of death. Taking the different storage conditions into account, the patterns of metal concentrations in the samples match well, suggesting that all three samples came from the same individual. The results of our research support the suggestion, often made in the literature, that Franz Schubert underwent cutaneous treatment with mercury for syphilitic illness many months before his death.

Reducing lead toxicity with advanced nanotechnology methods

Lead exposure remains a pressing global health concern, particularly due to its pervasive nature in our environment and the associated toxicological risks. This review article explores the multifaceted aspects of lead, including its physical and chemical properties, the epidemiological prevalence of lead poisoning, and the pathophysiological mechanisms underlying its toxicity. Clinical manifestations, particularly in occupational settings, highlight the significant health impacts on vulnerable populations. We will discuss current methodologies for the identification and detection of lead, emphasizing the importance of prevention and treatment strategies to mitigate exposure. Given the growing interest in sustainable remediation approaches, microbial remediation techniques are evaluated for their effectiveness in addressing lead contamination. Furthermore, this review underscores the potential of nanoparticles in modifying lead toxicity. Focusing on their role in both in vitro and in vivo conditions, we examine how nanoparticles can influence lead bioavailability and toxicity in various environments, including wastewater, soil, and plants. Our findings suggest that nanoparticles offer innovative solutions for reducing lead's harmful effects, thus providing a pathway for enhanced environmental and public health protection. This comprehensive review aims to inform researchers, healthcare professionals, and policymakers about the potential of cutting-edge nanotechnology methods in combating lead toxicity and improving health outcomes.

Infant cognitive home environment as a moderator for the association of prenatal lead on child language

Exposure to lead during early life, including in pregnancy, is toxic to neurodevelopment. Though public health initiatives have resulted in an overall reduction in lead exposure levels, lead remains a significant environmental hazard, requiring innovative efforts to mitigate the burden of early life lead. This study explored whether positive postnatal social experiences in the forms of positive caregiving and a rich cognitive home environment moderate the associations of prenatal lead on child neurodevelopmental outcomes including language skills, effortful control, and executive function skills. We leverage an analytic sample (N = 107) drawn from a prospective cohort of mother-infant dyads. Prenatal lead was measured from maternal urine, positive caregiving from observational methods, and cognitive home environment from a validated questionnaire. Results reveal a negative association of prenatal lead on child language when the cognitive home environment in infancy was poor (β=-0.32, p = 0.04) but not when the cognitive home environment in infancy was rich (β=0.20, p = 0.16). This buffering effect was not observed for the child outcomes of effortful control or executive function skills. Our results encourage future research into the provision of a rich cognitive home environment as a means of mitigating the detrimental effects of prenatal lead exposure on early child language skills.

Lead source apportionment and climatic impacts in rural environmental justice mining communities

After a sequence of natural disasters in Gila County, Arizona, USA environmental justice (EJ), mining areas, community members raised concerns about metal(loid)s exposure and origin. To address these concerns, non-residential sediments (0-2 cm, 2-15 cm, and 15-30 cm), household soil (0-2 cm), and indoor and outdoor dust samples were analyzed for metal(loid)s concentration and Pb isotopes via inductively coupled plasma mass spectrometry. To identify the potential sources of Pb, 37 studies were considered, and 21 different Pb isotopic ratios were documented and compared. Spearman's correlation and principal component analysis were used to investigate the co-occurrence of metal(loid)s associated with Pb. The results demonstrated a clear association (p < 0.05) between Pb and mining activity in households and non-residential locations as well as a co-occurrence with As, Cd, Cu, Mo, Sb, and Zn at 0-2 cm and in non-residential with As, Cd, and Zn at 2-15 cm and 15-30 cm. The outdoor household dust was impacted by a mixture of Pb sources and was associated with metal(loid)s coming from mining, wildfire, lead based-paint and landfill, whereas indoor Pb dust was associated mainly with metal(loid)s coming from geogenic sources. Further, 66% of town/city sediment samples across depth and 53.8% of outdoor dust samples were aligned with mining fingerprint and 30.1% of outdoor dust and 25% of household soil samples were aligned with the wildfire Pb isotopic ratio/fingerprint. The Positive Matrix Factorization model illustrates flood's ability to remobilize metal(loid)s from neighboring mine sites to the households' locations. Currently there is no established Pb isotopic ratio composition for wildfires in Arizona; this study lays the foundation for understanding the complex relationship between the myriads of lead sources in our environment, wildfires, and flooding.

Assessment of water quality and occurrence of multidrug-resistant clinically relevant bacteria in drinking water in the twin cities of Pakistan

Water filtration plants are a main source of drinking water for local populations in almost all big cities of Pakistan but these filtration plants are ineffective in eliminating contaminants from water. This study was conducted to evaluate water quality with specific focus on physicochemical parameters and bacterial contamination including occurrence of multidrug-resistant bacteria in drinking water collected from filtration plants (N = 64) of the twin cities of Pakistan. Physicochemical parameters were analyzed following American Public Health Association standard guidelines and total coliform count was determined using membrane filtration method. Gram-negative bacteria were isolated and characterized in terms of species and antibiotic susceptibility. Elevated levels of total dissolved solids, nitrates, total coliforms, lead and copper were found in several samples. Multivariate correlation coefficient revealed significant positive correlation between nitrate levels and total coliform count in bacteriologically contaminated samples. Antibiotic resistance patterns revealed multidrug-resistant and extensively drug-resistant bacteria with high resistance against third generation cephalosporins. Our results highlight the urgent need for improved water filtration processes and regular monitoring to provide safe drinking water to the local community.

Industrial air pollution and newborn hearing screening failure

Hearing loss in newborns is a prevalent issue that can hinder the growth of language skills and cognitive development. Given that hearing loss often co-occurs with other adverse birth outcomes and the recognized role of metals in causing such outcomes, it is conceivable that metals may also serve as a risk factor of hearing loss. This study examined the associations between maternal residential exposure to thirteen PM2.5-bound metals and failure in Newborn Hearing Screening (NHS) in offspring in New Mexico from 2008 to 2017 to ascertain possible implications of these environmental exposures. This retrospective cohort study included 141,406 births (7670 births in disease group and 133,736 births in non-diseased group) in New Mexico during 2008-2017. Thirteen PM2.5-bound metals released from the U.S. Environmental Protection Agency (EPA) Toxic Release Inventory (TRI) facilities were investigated potentially as risk factors. The RSEI model estimated maternal residential exposure to PM2.5-bound metals during pregnancy, and spatial log-binomial regressions, adjusted for confounders, calculated adjusted relative risks (aRRs) for the association with NHS failure. Findings indicated that maternal residential exposure to PM2.5-bound metals - including antimony, barium, beryllium, chromium, cobalt, manganese, mercury, vanadium, and zinc - during pregnancy were positively associated with NHS failure in offspring, showing aRRs ranging from 1.07 to 2.18. A significant trend was observed when exposures were categorized as zero, low, medium, and high of these metals. Our findings indicate that maternal exposure to these PM2.5-bound metals may adversely affect newborn hearing, underscoring air pollution as a modifiable risk factor for improving hearing health outcomes.

Predicting the amount of toxic metals and metalloids in silt loading using neural networks

Material deposited on road surfaces, called road dust, are known to contain different toxic elements. According to particle size, there are different fractions. Particles with an aerodynamic size less than or equal to 75 µm are called silt loading. As a result of exhaust and non-exhaust emissions from motor vehicles, silt loading deposited on the road surface contains toxic metals, non-metals, and metalloid like Cr, Ni, Zn, Cu, Co, Cd, Pb, and As. Through different pathways, these toxic elements can easily get into the soil, surface and ground water, plants, animals, and the human body. The high risk of contamination and the extent of toxic effects determine the need for their control and health regulation and systematic monitoring. Specific laboratory equipment is used to perform multiple measurements of toxic metal ions. The procedure is heavy and time-consuming due to the difficulties associated with stopping road traffic during sampling in large settlements and the standard elemental analysis technique ICP-MS that is usually applied. The paper proposes a method for predicting the amount of toxic elements in silt loading using artificial intelligence. The paper proposes the use of neural networks, using previously collected experimental data as a training base. The high prediction accuracy that is obtained (As-95.304%, Cd-99.616%, and Pb-98.832%) shows that the proposed prediction could successfully replace the standard elemental analysis.

Surviving not Thriving After Gunshot Wound: Prospective Study of Quality of Life, Posttraumatic Stress Disorder, and Employment

INTRODUCTION

Psychosocial morbidity, including posttraumatic stress disorder (PTSD), depression, and failure to return to work, is common following gunshot wounds (GSWs). GSW victims with retained bullets experience increased rates of elevated blood lead, putting patients at risk for toxic effects on cognition and mood. This pilot study was performed to examine associations between retained bullets and employment and psychosocial outcomes after GSW.

METHODS

Adult victims of interpersonal intentional GSW completed surveys using validated instruments to measure quality of life, PTSD, resilience, and substance use, and questions regarding employment during index hospitalization and at 1 and 3 mo. Survey data was linked to clinical records regarding injury severity and hospital course.

RESULTS

Sixty-three patients completed the baseline survey; 43 completed all 3 surveys. Median age was 29 (interquartile range, 21-40), injury severity score 13 (9-17), and hospital length of stay 6 d (4-10). The patient population was overwhelmingly Black and male (both 87.3%). Laparotomy was performed in 28 patients (44%). Forty-nine patients (77.8%) were working prior to injury, 1 (2%) at 1 month, and 34 (54%) at 3 months. Eight (12.7%) screened PTSD + at baseline; 38 (60.3%) were PTSD + at 3 months. Three-month PTSD + patients were similar to PTSD-patients in all clinical and demographic variables. For 3-month PTSD + patients, all quality of life component scores were worse than for PTSD-patients. Presence of retained bullets was not associated with any differences in psychosocial outcome at 3 months.

CONCLUSIONS

GSW is associated with significant psychosocial morbidity, including a large decline in employment. PTSD affects approximately half of patients, consistent with prior reports. In this pilot study, PTSD + patients suffered from reduced quality of life.

Sustainable Strategies for Converting Organic, Electronic, and Plastic Waste From Municipal Solid Waste Into Functional Materials

The valorization of municipal solid waste permits to obtain sustainable functional materials. As the urban population burgeons, so does the volume of discarded waste, presenting both a challenge and an opportunity. Harnessing the materials and the latent energy within this solid waste not only addresses the issue of disposal but also contributes to the innovation of functional materials with applications in the energy, electronics, and environment sectors. In this perspective, technologies for converting, after sorting, municipal solid waste into valuable metals, chemicals, and fuels are critically analyzed. Innovative approaches to convert organic waste into functional carbon materials and to create, from plastic and electronic wastes, metal-organic frameworks for energy conversion, storage, and CO2 adsorption and conversion are proposed. Green hydrometallurgy routes that permit the recovery of precious metals avoiding noble metals' oxidative leaching, thus avoiding their downcycling, are also highlighted. The reclaimed precious metals hold promise for use in optoelectronic devices.

Endocrine Disruptors Chemicals: Impacts of Bisphenol A, Tributyltin and Lead on Thyroid Function

The large-scale industrial production characteristic of the last century led to an increase in man-made compounds and mobilization of natural compounds, many of which can accumulate in the environment and organisms due to their bioaccumulation and biomagnification properties. The endocrine system is especially vulnerable to these compounds that are known as endocrine disruptor chemicals (EDCs). Thyroid hormones (THs) are essential for normal development and growth, besides being the main regulators of basal metabolic rate. Thus, compounds able to affect THs synthesis, transport, and action could produce important deleterious effects, impacting the development of metabolic and endocrine diseases. Herein, we will review the main effects of EDCs on the thyroid axis, with special emphasis on the widely used substances bisphenol A (BPA), employed in the synthesis of polycarbonate plastics and epoxy resins; tributyltin (TBT), an organotin chemical substance widely used in several agro-industrial applications; and lead (Pb), a ubiquitous environmental and occupational polluting heavy metal. Exposure to these EDCs occurs mainly from the ingestion of contaminated food and beverages. Furthermore, there are few epidemiological studies evaluating human risk, and experimental studies employ different exposure models, making it difficult to integrate results. However, even low doses of these EDCs warn of thyrotoxicity. Since THs homeostasis is essential for health and humans are increasingly being exposed to EDCs, it is important to clarify which substances might act as thyroid hormone system disrupting chemicals and how they act in order to try to overcome their deleterious effects and limit the exposure to these compounds.

Prevalence and risk factors of elevated blood lead levels in 0-6-year-old children: a national cross-sectional study in China

Aims

To evaluate the prevalence and risk factors of elevated blood lead levels (EBLL) among the pediatric population in China.

Methods

Questionnaire investigation about Lead exposure information, venous blood samples collection and BLL detection are conducted. A total of 32,543 subjects aged 0-6 years old (from 1 month old to under 7 years old) were recruited from May 2013 to March 2015 in 15 provinces of China.

Results

The overall weighted prevalence of EBLL which is defined as BLL ≥ 50 μg/L in this study is 4.1%, as for different geographical regions, with lowest prevalence in the western region of China, lowest prevalence in Shaanxi province and highest in Hebei province. In 0-3-Year-old children, female weighted prevalence of EBLL (4.0%) is higher than male (2.4%), while in 3-6-Year-old children, male (8.3%) is higher than female (6.3%). Bad hygienic habits, some kind of custom, using folk prescriptions, living on the ground floor, poor drinking water quality, indoor air pollution and passive smoking exposure remain risk factors of EBLL (BLL ≥ 50 μg/L) of 0-6-year-old (from 1 month old to under 7 years old) children in China, after adjustment of gender, age, geographical region, annual household income, educational background and occupation of the parents and caregivers.

Conclusion

This study reveals the prevalence and risk factors for EBLL (BLL ≥ 50 μg/L) in 0-6-Year-old Children of China. We hope this study will help public health education and inform policy for preventing and eradicating children's lead poisoning in China.

Combination of 10-hydroxy-decanoic acid and ZnO nanoparticles abrogates lead acetate-induced nephrotoxicity in rats: targeting oxidative stress and inflammatory signalling

Lead is a heavy metal contaminant that can cause significant alterations in renal structure and function, resulting in nephrotoxicity. The fatty acids of royal jelly exhibit immunoregulatory, anticancer, anti-inflammatory, and antioxidant properties, which have garnered significant interest. The most prevalent among them is 10-hydroxydecanoic acid (10-HDA). Zinc oxide nanoparticles (ZnONPs) demonstrate a renoprotective effect, likely due to their antioxidant, anti-inflammatory, and antiapoptotic properties. This study evaluated the therapeutic efficacy of 10-HDA and ZnONPs, administered either as monotherapy or in combination, against lead-induced nephrotoxicity. Male rats were orally administered lead acetate (PbAc) for three months, followed by the administration of 10-HDA and/or ZnONPs for one month. Exposure to PbAc resulted in elevated renal lead concentration, as well as increased serum levels of urea, creatinine, and cystatin C. The condition resulted in damage to the renal parenchyma, characterised by degenerative glomeruli and tubules, and exhibited the highest lesion score. Nrf2 and HO-1 exhibited reduced expression and diminished antioxidant enzyme levels subsequent to PbAc poisoning. Additionally, there was an increase in the inflammatory and apoptotic signalling through the p-IKK/NF-κB axis. The administration of 10-HDA and ZnONPs significantly decreased renal lead levels and improved antioxidant capacity. Moreover, renal inflammatory markers (TNF-α, p-IKK, IL-1β, IL-6, and IL-8) and proapoptotic indicators (Bax and Caspase-3) were significantly suppressed. The combined therapy demonstrated a synergistic effect (combination index < 1). In conclusion, the results indicated that 10-HDA and ZnONPs have the potential to be a supplement or even an effective treatment to alleviate the adverse effects of lead poisoning. This is potentially attributed to their potent ameliorative actions against oxidation, inflammation, and apoptosis.

Toxic Effects of Waterborne Pb Exposure on Hematological Parameters and Plasma Components in Starry Flounder, Platichthys stellatus

Lead (Pb) is a non-essential toxic metal that accumulates in aquatic environments, negatively impacting fish health. This study evaluated the acute toxicity of Pb in starry flounders (Platichthys stellatus). Fish (41 ± 8.1 g, 14 ± 0.9 cm) were exposed to Pb concentrations of 0, 10, 20, 40, 80, 160, 320, and 640 mg Pb2+/L for 96 h. The lethal concentration (96 h LC50) was determined to be 227 mg Pb2+/L. Hematological analysis showed significant decreases in RBC counts, hemoglobin, and hematocrit, while MCH and MCHC increased at ≥160 mg Pb2+/L. Plasma calcium levels significantly decreased following Pb exposure, and AST activity was reduced. These findings suggest that acute waterborne Pb exposure adversely affects survival, hematological parameters, and plasma components in P. stellatus, providing insight into Pb toxicity in aquatic organisms.

Pea Peptide Modulates Abnormal Aβ Production in PC12 Cells Induced by Lead Exposure

Lead (Pb) exposure poses significant health risks, particularly in neurodegenerative diseases such as Alzheimer's disease (AD). This study investigates the neuroprotective effects of pea peptide (PP4) on PC12 cells exposed to Pb. Using Cell Counting Kit-8 (CCK-8), pretreatment with PP4 at 50 and 200 µM concentrations significantly improved cell viability compared to Pb-only treated cells (P < 0.05), indicating a protective effect. Moreover, Pb exposure led to increased Amyloid Precursor Protein (APP) expression at 10 and 20 µM after 24 h (P < 0.05), while β-site amyloid Precursor Protein Cleaving Enzyme 1 (BACE1) levels were elevated across all concentrations tested (P < 0.05). We established that PP4 can mitigate Pb-induced cytotoxicity and reduce the expression of APP and BACE1 by activating the Phosphoinositide 3-kinase / Protein Kinase (PI3K/AKT) signaling pathway. This study highlights the potential of PP4 as a therapeutic agent in preventing neurotoxic damage associated with lead exposure, suggesting a novel approach for the management of AD.

Human health risk assessment of toxic metals in Nass smokeless tobacco in Iran

Smokeless tobacco (ST) products create a deadly combination of addiction to nicotine and exposure to toxic substances. Nass is the predominant smokeless tobacco (ST) product consumed in Iran. This study was conducted to evaluate the levels of arsenic (As), lead (Pb), nickel (Ni), and cadmium (Cd) in Nass brands available in the Iranian market. A total of 42 samples were analyzed for the levels of heavy metals using flame atomic absorption spectrometry. The study also evaluated the risk associated with carcinogenic and non-carcinogenic toxic metal contamination in smokeless tobacco in Iran. The level of heavy metals measured in various Nass samples was ranked as Pb > Ni > Cd > As .The mean levels (range) of Pb, Cd, As, and Ni in Nass samples were determined to be 38.71 µg/g (17.60-57.70), 2.90 µg/g (1.20-3.65), 0.71 µg/g (0.25-1.17), and 23.24 µg/g (4.95-44.65), respectively. The levels of Pb, Cd, As and Ni in handmade samples are higher than products manufactured at the plant. The levels of Pb, Cd and Ni in all samples were higher than the Swedish Match recommended limits. While the levels of As in 12% of samples were lower than the standard defined by the Swedish Match. The Estimated daily intake (EDI) values for As, Cd, Ni and Pb are below the reference dose (RfD) established by the Environmental Protection Agency. The findings indicate that the target hazard quotient (THQ) and the hazard index (HI) values in the study were below 1. In this study, for the first time demonstrated that Nass consumers in Iran are at risk of exposure to Pb, As, Cd, and Ni. Consequently, the health system should prioritize raising public awareness about the health risks associated to Nass.

Protective effects of Juglans regia oil on lead acetate-induced reprotoxicity in rats: an antioxidant, histological and computational molecular study

BACKGROUND

Lead (Pb) is a metal that affects many body systems, primarily the male reproductive system. This study aimed to examine the phytochemical profiling and beneficial effects of Juglans regia oil (JRO) in alleviating lead-induced reprotoxicity-associated oxidative injury in rats. Adult male Wistar rats were randomly divided into four groups as follows: control group received no treatment, Pb group was exposed to 0.344 g kg-1 bw of Pb acetate, Pb + JRO group was co-treated with Pb plus walnut oil (0.9 g kg-1 bw) and JRO group received walnut oil only.

RESULTS

Pb-treated rats showed significantly decreased gonado-somatic index, count and viability of sperm. Testosterone levels decreased in Pb-treated animals. Besides, Pb disrupted the oxidative/antioxidative status, the plasmatic lipase activity and testicular Pb content. Furthermore, Pb produced testis histopathological features, especially cell degeneration, atrophy and tubular disarrangement. Co-treatment with JRO was found to be effective for recovering the increased testicular oxidative damage-associated histological features in the Pb group. This was supported by the in silico modeling results.

CONCLUSION

The in silico analyses revealed that JRO compounds bound androgen receptor and RAC-alpha serine/threonine kinase with high affinities, which together with pharmacokinetic properties and molecular interactions satisfactorily support the beneficial in vivo findings in the Pb + JRO group of rats. © 2024 Society of Chemical Industry.

Genetic Damage and Multi-Elemental Exposure in Populations in Proximity to Artisanal and Small-Scale Gold (ASGM) Mining Areas in North Colombia

This study evaluates DNA damage and multi-element exposure in populations from La Mojana, a region of North Colombia heavily impacted by artisanal and small-scale gold mining (ASGM). DNA damage markers from the cytokinesis-block micronucleus cytome (CBMN-Cyt) assay, including micronucleated binucleated cells (MNBN), nuclear buds (NBUDs) and nucleoplasmic bridges (NPB), were assessed in 71 exposed individuals and 37 unexposed participants. Exposed individuals had significantly higher MNBN frequencies (PR = 1.26, 95% CI: 1.02-1.57, p = 0.039). Principal Component Analysis (PCA) identified the "Soil-Derived Mining-Associated Elements" (PC1), including V, Fe, Al, Co, Ba, Se and Mn, as being strongly associated with high MNBN frequencies in the exposed population (PR = 10.45, 95% CI: 9.75-12.18, p < 0.001). GAMLSS modeling revealed non-linear effects of PC1, with greater increases in MNBN at higher concentrations, especially in exposed individuals. These results highlight the dual role of essential and toxic elements, with low concentrations being potentially protective but higher concentrations increasing genotoxicity. Women consistently exhibited higher MNBN frequencies than men, suggesting sex-specific susceptibilities. This study highlights the compounded risks of chronic metal exposure in mining-impacted regions and underscores the urgent need for targeted interventions to mitigate genotoxic risks in vulnerable populations.

Human health risk assessment of lead exposure from soil ingestion in a French pilot study: insights from the application of a new bioaccessibility approach

Despite the consensus on the importance of considering the bioavailability of metal(loid)s by measuring their bioaccessibility when assessing exposure, integrating these parameters into risk calculations often involves proprietary approaches that lack adequate justification. This is the case with the in vitro unified bioaccessibility method (UBM), which is widely used in Europe to assess the bioaccessibility of metal(loid)s in the event of soil ingestion. This study proposes a comprehensive operational approach that incorporates bioaccessibility to refine human exposure and risk assessments. A pilot study of 45 Pb-contaminated soil samples collected in and around Paris highlighted the importance of carefully following soil preparation protocols. Specifically, sieving the soil to 250 µm without mechanical milling is recommended for determining both bioaccessible and total concentrations. A simplified test using dilute hydrochloric acid can predict the bioaccessibility of metal(loid)s in first-tier screening. This affordable, single-extraction method is easy to use in analytical laboratories and is both fast and reproducible. For second-tier validation studies, the UBM protocol should be applied to a limited number of samples. With the new approach, the relative bioavailability can be directly calculated using an in vivo/in vitro equation in the stomach compartment, thus, enabling UBM validation. The results of the pilot study demonstrated that to refine exposure assessments, adjusting chronic daily intake using relative bioavailability data was more effective than were classical approaches based on total concentrations. This method offers a promising perspective for stakeholders in managing polluted sites and soils.

Antioxidant capacity, biochemical composition, and mineral composition of leaves in two apple species (Malus domestica Borkh. and M. kirghisorum Al. Fed. & Fed.)

BACKGROUND

Apple leaves are a rich source of bioactive compounds such as phenolics, flavonoids, and essential minerals, which exhibit significant antioxidant and therapeutic properties. This study focuses on comparing the biochemical composition, antioxidant capacity, and mineral contents of Malus domestica Borkh. cultivars and M. kirghisorum Al. Fed. & Fed. genotypes. The goal is to identify potential health-promoting compounds and establish a basis for utilizing apple leaves as a sustainable resource in the food, pharmaceutical, and cosmetic industries.

RESULTS

The study revealed significant biochemical and nutritional variation among the genotypes. Total antioxidant capacity ranged from 36.00 in 'A12' to 59.50% in 'Starking Delicious'. Total phenolic content varied between 70.42 in 'A28' and 147.45 mg GAE/100 g in 'Granny Smith', while total flavonoid content ranged from 15.43 in 'A28' to 38.66 mg QE/100 g in 'A16', demonstrating considerable variability in bioactive compound composition. Correlation matrix analysis identified several significant relationships. Total phenolics and total flavonoids showed a positive correlation (r = 0.52**), while calcium strongly correlated with magnesium (r = 0.79**), potassium (r = 0.52**), and phosphorus (r = 0.52**), underscoring their physiological interconnections. Multiple regression analysis clarified key traits. Total phenolic content was positively influenced by total flavonoids (β = 0.52, p < 0.00). Calcium was strongly associated with magnesium (β = 0.52, p < 0.00) and sodium (β = 0.46, p < 0.00), reflecting their synergistic roles in cellular and metabolic functions. Principal component analysis revealed that the first three components explained 57.80% of the total variation. PC1 (30.56% variance) was predominantly associated with calcium, potassium, phosphorus, and magnesium. PC2 (14.16%) highlighted the relationship between manganese and total antioxidant capacity, while PC3 (13.08%) reflected the influence of lead, total phenolics, and total flavonoids. Heat map analysis indicated that the calcium, phosphorus, sulfur, phenolic compounds, and antioxidant activities in subgroup A1 suggest that the genotypes may be beneficial for health. Additionally, the accumulation of heavy metals such as lead, nickel, and aluminum in subgroup B1 could pose a health risk; however, the genotypes 'A18', 'A21', 'A21-1', and 'A22' possess the capacity to reduce this accumulation.

CONCLUSIONS

The results highlight the nutritional and therapeutic potential of apple leaves as a natural source of antioxidants and essential minerals. In particular, the genotypes 'A21-1' and 'A16' stand out due to their high content of bioactive compounds and nutrients, offering promising prospects for further research and applications. These findings contribute to the conservation of wild apple genetic resources and their potential for industrial use.

CLINICAL TRIAL NUMBER

Not applicable.

Determination of Lead in Fruit Grown in the Vicinity of Tailings Dams of a Mine in Zacatecas, Mexico

This study analyzed the lead concentrations in fruit grown near tailings dams of a mine in Zacatecas (Mexico) using electrochemical techniques. A 3 × 4 factorial design, with three levels of apple tree distance (low, medium, and high) and four levels of apple tree part (stem, leaf, pulp, and peel), was performed to predict the pathway for contamination (foliar or radicular). Samples of each apple tree part, soil, and irrigation water were collected. The lead concentrations were determined by anodic stripping voltammetry. The results showed lead concentrations of 172 ppm and 0.012 ppm for the soil and irrigation water, which were discarded as sources of contamination since they were below the allowable limits by the Mexican standards (400 ppm and 2 ppm, respectively). However, lead concentrations in the stem and leaf ranged from 6.6 ppm to 30.7 ppm, and pulp and peel exceeded 300 times the allowable limit by the Codex Alimentarius (0.1 ppm). The apple tree part was a significant factor in the experimental design. Hence, it was predicted that the pathway for contamination is by foliar absorption. The fruit is highly contaminated by its proximity to the mine. Therefore, mitigation actions must be performed to avoid health risks for the consumers of this fruit.

Ameliorative role of bioactive compounds against lead-induced neurotoxicity

Lead (Pb) is an environmental toxin ubiquitously present in the human environment due to anthropogenic activities and industrialization. Lead can enter the human body through various sources and pathways, such as inhalation, ingestion and dermal contact, leading to detrimental health effects. The majority of lead that enters the body is removed by urine or feces; however, under chronic exposure conditions, lead is not efficient, as lead is absorbed and transferred to numerous organs, such as the brain, liver, kidney, muscles, and heart, and it is ultimately stored in mineralizing tissues such as bones and teeth. The central nervous system is the most affected among all the organs and systems affected, as lead is a known neurotoxin. Lead absorption is elevated in the fasting state than in the fed state. Chelation therapy, which is used to treat lead poisoning, has various adverse effects, making this treatment detrimental because it disrupts the levels of other essential elements and redistributes lead to various tissues. One of the main mechanisms by which lead induces toxicity is through the generation of reactive oxygen species. Hence, bioactive compounds that are the source of antioxidants if consumed along with ongoing lead exposure can ameliorate the toxic effects of lead.

Employing Mesoporous Nitrogen Containing Carbon for Simultaneous Electrochemical Detection of Heavy Metal Ions

Heavy metal ions are major contributors to water pollution, posing significant threats to both ecological balance and human health due to their carcinogenic properties. The increasing need for heavy metal detection highlights the advantages of electrochemical methods, which offer high sensitivity and efficiency. Herein mesoporous nitrogen containing carbon (MNC) was utilized for the simultaneous determination of heavy metals using square wave voltammetry technique in the established conditions of a buffer pH of 5.0. MNC demonstrated low detection limits (1, 10 and 50 μM), wide linear ranges (1 μM-6 mM, 10 μM-7 mM and 50 μM-17 mM), and high sensitivities (2.5 μA μM-1 cm-2, 1.03 μA μM-1 cm-2 and 5.14 mA mM-1 cm-2) for, Pb2+, Cd2+ and Cu2+, respectively. Moreover, the reproducibility, and selectivity of the sensor was investigated in the presence of K+, Mg2+, Zn2+, Ni2+, and Fe3+ which are the possible interferents present in water.

Childhood Pb-induced cognitive dysfunction: structural equation modeling of hot and cold executive functions

BACKGROUND

Childhood lead [Pb] exposure has been consistently linked to neurotoxic effects related to the prefrontal cortex, a critical mediating structure involved in decision-making, planning, problem-solving, and specific aspects of short-term memory, i.e., the components of executive functions [EFs]. Limited studies have taken a deeper phenotyping approach that assess Pb's effects across multiple EF dimensions simultaneously, which can be organized into hot [e.g., reward, motivation] and cold [e.g., primary cognitive processing] dimensions.

OBJECTIVE

We investigated whether childhood Pb exposure affects hot and cold EF dimensions and assessed any sexually dimorphic effects.

METHODS

Leveraging a longitudinal birth cohort based in Mexico City, children's (n = 602) whole blood Pb levels (mean 23.66 μg/L) were measured at ages 4-6 and they were administered several EF tasks at ages 6-9. Confirmatory factor analysis confirmed that six EF tests estimated two latent variables representing hot and cold EF dimensions. Structural equation modeling [SEM] estimated the neurotoxic effect of childhood Pb exposure on latent variables of hot [higher scores indicate improved performance] and cold [higher scores indicate poorer performance] EFs. Subsequently, a multi-group SEM explored potential effect modifications by child sex.

RESULTS

Pb exposure was significantly associated with negative impacts on hot EF performance [b = -0.129, p = 0.004]. In both males (b = -0.128, p = 0.032) and females (b = -0.132, p = 0.027), childhood Pb exposure was significantly associated with a reduction in hot EF performance, with no evidence of an interaction with sex. Additionally, we found no association between Pb exposure and cold EF performance [b = 0.063, p = 0.392] and no notable sex differences.

IMPACT

The present study leverages a sophisticated SEM framework as an exploratory tool and a neurotoxic framework to analyze multidimensional cognitive data, aiming to delineate hot and cold EFs. Our findings are consistent with neurotoxicity secondary to childhood Pb exposure impacting hot EF performance more than cold EF, though comparable trends were noted in cold EF performance for both sexes. Our approach uniquely captures hot EF, the more emotional and self-regulatory aspect of EF, adding a novel dimension to the literature on Pb exposure and cognitive development.

Investigating the role of food pollutants in autism spectrum disorder: a comprehensive analysis of heavy metals, pesticides, and mycotoxins

Food pollutants, including heavy metals, pesticides, and mycotoxins, have been proposed as potential risk factors for autism spectrum disorder (ASD) during pregnancy and early childhood. This paper examines the impact of food pollutants on ASD risk. A systematic search through PubMed, Google Scholar, and Sciverse yielded studies from 1990 to present. Research indicates elevated levels of heavy metals in children with ASD, linking pesticides and toxins to brain development disruptions. Mycotoxins, specifically, show a correlation with ASD and can contaminate food, posing a threat to neurodevelopment. Strategies like choosing organic foods and reducing exposure to toxins may benefit individuals with ASD and those vulnerable to the disorder. Further research is essential to comprehend the food pollutant-ASD relationship and devise effective exposure reduction strategies.

Synergistic ameliorating effect of dithiophenolate chitosan nanoparticle and Solanum nigrum combination against lead-induced cardiotoxicity in rats

Lead (Pb) toxicity is one of the most common causes of human cardiotoxicity. We evaluated the therapeutic role of Solanum nigrum extract (SNE) and dithiophenolate-chitosan nanoparticle (DTP-CSNP) on Pb-induced cardiotoxicity in rats, and the results were compared with the dimercaptosuccinic acid (DMSA, reference drug). Additionally, the combination effect of SNE and DTP-CSNP against Pb-induced cardiotoxicity was assessed. The study focused on the determination of the antioxidant, anti-inflammatory, anti-apoptotic, and cardiotherapeutic functions of SNE (375 mg/kg), DTP-CSNP (20 and 40 mg/kg), and their combination (SNE + DTP40). The characterization of SNE and DTP-CSNP was studied. The results showed that SNE contains phenolics, flavonoids, ascorbic acid, and minerals, which may play an important role in its therapeutic effect. SNE, DTP20, and DTP40 exhibited a therapeutic impact against cardiotoxicity by reducing Pb levels, oxidative stress, inflammation, and cell death. Moreover, they regulated the abnormal levels of cardiac biomarkers induced by Pb toxicity. DTP-CSNP showed a superior therapeutic effect to DMSA, and the SNE + DTP40 combination displayed a synergistic anti-cardiotoxic effect (combination index < 1). These results were in harmony with heart histopathology. Thus, the combination of both SNE and DTP-CSNP has powerful efficacy in the treatment of cardiotoxicity and can be a good alternative to DMSA.

Early economic evaluation of chelation therapy in kidney transplant recipients with high-normal lead

BACKGROUND

Kidney transplant recipients (KTR) with high-normal lead have a higher risk of graft failure (GF). Clinically, chelation therapy using meso-2,3-dimercaptosuccinic acid (DMSA) removes lead. Despite the proposal that chelation therapy can prevent GF through lead removal, evidence is lacking. To guide research efforts, we conducted an early economic evaluation, aiming to explore the economic feasibility of screening for and implementing chelation therapy with oral DMSA for high-normal plasma lead concentrations in KTR (i.e., the intervention) compared to standard of care.

METHODS

A Markov model simulated the life course of 10,000 KTR in the Netherlands from a societal perspective. Transition probabilities were estimated using the data from TransplantLines Food and Nutrition Biobank and Cohort study. Costs and utilities were sourced from publications and public data. Model robustness was investigated through deterministic and probabilistic sensitivity analyses. Various administration strategies were tested. Five-year costs were calculated from a healthcare payer's perspective. Value of information was assessed.

RESULTS

The intervention was cost-saving and improved health, leading to a dominant incremental cost-effectiveness ratio. The result was most sensitive to transition probabilities (led by GF, followed by death with functioning graft and after graft failure). The probability of the intervention being cost-effective was 60%. Chelation strategies did not affect the result. The intervention applied to the Dutch KTR population could save €27 million in the initial five years. Further research is desirable if the cost of obtaining perfect information on GF survival is approximately below €4,000/KTR (all uncertainties under €5,000/KTR).

CONCLUSION

The cost-effectiveness of the intervention is robust in KTR, except when considering the uncertainties around (graft) survival probabilities. Applying chelation therapy in the new setting we studied holds significant potential. However, trials that systematically assess the efficacy, administration strategies, and impacts on survival are crucial in updating the current evaluation and informing policies.

Validation and optimization of a Prussian blue nanoparticle-based method for efficient detection and removal of lead ions in environmental samples

Lead (Pb2+) poisoning in water is now a more serious environmental concern than any other, due to its potential toxicity and accumulation in the human body. The Prussian blue nanoparticles (PBNPs) effectively removed organic and inorganic pollutants from aqueous solution. This study comprehensively investigates the adsorption properties of PBNPs for Pb2+ removal, optimizing experimental conditions through various analytical techniques. Key validation parameters-linearity, precision, accuracy, the limit of detection (LOD), the limit of quantification (LOQ), and the method detection limit (MDL)-were assessed. We investigate a comprehensive study focused on the adsorption properties of Prussian blue nanoparticles (PBNPs) for Pb2+ removal from aqueous solutions. The adsorption process was most effective at pH 7.5, achieving an adsorption capacity of 190 mg g-1. Kinetic analysis revealed that the adsorption follows a pseudo-second-order model with a chemisorption mechanism, while isothermal studies confirmed monolayer adsorption consistent with the Langmuir model. Thermodynamic analysis indicated that the process is spontaneous and endothermic. The Pb2+ concentration was precisely measured using graphite furnace atomic absorption spectroscopy (GFAAS) and flame atomic absorption spectroscopy (FAAS), with strong linearity (R 2 = 0.997), LOQ = 0.179 mg L-1, and LOD = 0.056 mg L-1 for FAAS. These findings show that the PBNPs have a significant potential for effective Pb2+ removal and are reusable, making them suitable for eco-friendly remediation applications. Validation parameters confirmed that trace Pb2+ levels in environmental samples were accurately and precisely detected. The study emphasizes the high absorption capacity of PBNPs for lead, which was evaluated using different experimental approaches and methodologies.

PbSO4 reaction mechanism in oxygen and reduction atmospheres during co-smelting process with primary lead material

At present, lead-containing wastes have increasingly become the raw materials together with primary lead concentrate for lead production to meet the ever-increasing lead demand market. PbSO4 is the dominant component in the lead-containing wastes, nevertheless, its reaction behavior during lead smelting is not sufficiently investigated. This study investigated PbSO4 decomposition behaviors and phase transformation mechanisms at oxidizing and reductive atmospheres and various gas flow rates. The investigations reveal that increasing the temperature and decreasing the oxygen partial pressure of the decomposition atmosphere can accelerate PbSO4 decomposition degree. PbSO4 decomposition intensity under different atmospheres follows the order of reducing atmosphere > inert atmosphere > oxidizing atmosphere. PbSO4 decomposition path was identified: at a non-reductive atmosphere, the decomposition of PbSO4 belongs to a multi-step decomposition process, PbSO4 gradually decompose into xPbO·PbSO4 (x = 1, 2, 4 in turn) and finally PbO. At a reductive atmosphere, the multi-step decomposition process was accelerated significantly, at the same time, the reduction decomposition path PbSO4 → PbS was increasingly dominant with the extension of decomposition time. PbS and Pb were generated successively. Therefore, a suitable reducing atmosphere is suggested to co-smelt PbSO4-bearing wastes in primary lead smelting furnace.

Paraffin-based composites containing high density particles: lead and bismuth and its' oxides as γ-ray shielding materials: an experimental study

Shielding nano- and microcomposites have emerged as a promising solution in the constantly growing requirements and expectations in the field of radiological protection. The majority of gamma and X-ray shielding nanocomposites are based on polymers due to lightweight, low cost and flexibility as the inviting features in comparison to traditional lead shields. Taking this into consideration, the following study proposes gamma-ray shielding composites characterized by their susceptibility to shape change using the heat and manual pressure. The paraffin-based composites were filled with pure lead and bismuth particles (Bi and Pb, in one mass fraction: 10 wt%) as well as it's oxides: bismuth (III) oxide (Bi2O3) particles and lead (II,IV) oxide particles (Pb3O4) (manufactured in two concentrations: 10 and 50 wt%). Based on experimental studies utilizing 60Co the half-value layers were calculated approximately 13-14 cm and ca. 9 cm for 10 wt% and 50 wt% filler concentration, respectively. The relatively quick and straightforward manufacturing process, utilizing two commercially available components, allows for the production of a gamma-ray shielding composite featuring a variety of shape choices, facilitating its use in areas where acquiring complex shields remains problematic, or the desired shape development requires repetition of the production process, changes in some of its stages and modification of the composition.

Design and simulation of a highly efficient eco-friendly, non-toxic perovskite solar cell

A highly efficient and nontoxic material methylammoniumtin(II) iodideperovskite solar cell is proposed. This proposed solar cell uses CH3NH3SnI3 as the absorber layer, TiO2 as an Electron transport layer (ETL), Indium tin oxide as a buffer layer, and Copper(I) oxide as the hole transport layer (HTL). The device is simulated using the SCAPS-1D simulation tool. This study details the optimization of a set of parameters, including the defect densities and the thickness of the absorber layer. The proposed structure is highly optimized result of 31.73% of enhanced power conversion efficiency (PCE), a JSC of 24.526 mA/cm2 (short-circuit current), FF of 81.40% (fill factor), and a VOC of 1.56 V (open-circuit voltage) is obtained through simulation process. Compared to previously reported works, the performance of the device has improved significantly due to better optimization. Along with this electrical characteristic temperature analyses, conductance voltage, capacitance-voltage, and bandgap analyses have also been carried out to examine the device's efficiency and performance.

Dimethylamine Bismuth Iodide: A Lead-Free Perovskite Enabling Ultra-Sensitive UVC Photodetection with Low Operating Voltage and High Detectivity

Ultraviolet (UV) photodetectors (PDs) are essential for various applications, but traditional materials face challenges in cost, fabrication, and performance. This study introduces dimethylamine bismuth iodide (DMABI) as a promising lead-free perovskite for UV PDs, particularly in the UVC region. DMABI demonstrates exceptional device parameters, including an ultralow dark current of 0.12 pA at 0.05 V, a high on/off ratio of 7.1 × 104, and a peak detectivity of 3.18 × 1013 Jones. The unique structure of DMABI, with isolated octahedral units, ensures minimal connectivity, significantly reducing dark current. When exposed to high-energy UV light, carriers gain sufficient energy to hop between octahedrally coordinated bismuth centres, resulting in substantial photocurrent. The small size of the organic cation facilitates efficient charge transfer, contributing to high responsivity (1.46 A W-1) and external quantum efficiency (up to 717%). These results establish DMABI as a superior, low-cost candidate for UV photodetection, addressing limitations of existing materials. The study provides insights into the molecular mechanisms driving these characteristics and highlights potential for future advancements in UV PD technology.

Effect of co-exposure to multiple metals (Pb, Cd, Cr, Hg, Fe, Mn and Ni) and metalloid (As) on liver function in Swiss albino mice

The study examined the cumulative toxic effect of multiple elements, As, Pb, Cd, Cr, Hg, Fe, Mn and Ni on the liver function and their association with inflammation and apoptosis. To explore the health consequence of simultaneous exposure to multiple metals and metalloid, male and female Swiss Albino mice were randomly divided into 14 groups and subjected to different doses [MPL (maximum permissible limit), 1×, 5×, 10×, 50× or 100×] of metal(loid)s mixture via drinking water for 8 weeks. Data showed that combined effect of multiple elements impaired the liver function. This was associated with significant decrease in the antioxidant enzymes and the elevation in lipid peroxidation for high exposure dose of 50× and 100× (p < 0.05). The metal(loid)s mixture exposure led to significant increase (p < 0.05) in cytokines, TNF-α, IL-6 and effector caspases (3 and 6) in exposure groups above 10× dose. Histopathological observation also revealed significant damage in the hepatic tissue on exposure to high dose. Dose dependent accumulation of respective elements (As, Cd, Cr, and Pb) in the liver was observed in each of the exposure groups. However, similar dose related increment was not observed for essential metals such as Ni, Fe and Mn. Differential accumulation of metals in the liver may be attributed to the effect of co-contaminant exposure, which could affect the divalent cation absorption due to antagonism and competitive transport process. Overall findings in this study manifest the complexity of possible joint effect of co-exposure to multiple metals and metalloid on the liver function.

Evidence linking cadmium and/or lead exposure to immunomodulatory effects in mammals based upon an adverse outcome pathways approach, and research perspectives

For decades, studies have shown how exposure to non-essential trace metals such as lead (Pb) and cadmium (Cd) largely impact global wildlife. Ecoimmunotoxicology has emerged in the past two decades and focuses on the effects of pollutants on the immune system of free-ranging organisms. Adverse outcome pathways (AOPs) represent a conceptual approach to explore the mechanistic linkage between a molecular initiating event and adverse outcomes, potentially at all biological levels of organisation. The present paper proposes putative AOPs related to the effects of Cd, Pb, and the mixture Cd-Pb, on the immune system of mammals to address future questions in ecoimmunotoxicology. Molecular Initiating Events for both metals relate to entrance in cells through Ca2+ channels or bond to cell surfaces. Exposure to Cd, Pb and Cd-Pb share several similar Key Events (KEs), primarily an increase of oxidative stress (OS) in immune cells through production of reactive oxygen species. For both metals and the mixture, OS affects mitochondrial membranes, and induces apoptosis, ultimately decreasing immune cell number. Both metals affect innate immune system through nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) inflammatory signalling pathways, leading to an upregulation of inflammatory markers and mediators. Adaptive immune system is also affected by the exposure to both metals though a decrease of CD4+/CD8+ ratio, a decrease of MHCII, an inactivation of TH1 and TH2 response, and an inhibition of the humoral response mediated by various Ig. Mixture effects of Cd-Pb are less documented resulting in a more speculative AOP, but potential synergic and antagonistic effects were identified. According to our AOPs, further research in ecoimmunotoxicology of metals in free-ranging mammals should focus on KEs related to NF-κB/MAPK inflammatory signalling pathways, changes in CD4+/CD8+ ratio and MHCII complexes, and on AOs related to auto-immune disorders and on the effective increase of infection rate, particularly in case of exposure to metal mixtures.

Assessment of Blood Lead Level of School Children in 10 Cities of India: A Cross-Sectional Study

OBJECTIVES

To assess the blood lead level (BLL) of school children in 10 cities of India.

METHODS

This multi-centric cross-sectional study enrolled participants from randomly selected schools. Data on demographic details, socioeconomic status (SES) and anthropometric indicators was collected. Samples were collected for assessment of lead level in blood. Inductively coupled plasma-optical emission spectrometry technique was used to assess BLL.

RESULTS

From April 2019 through February 2020, 2247 participants were recruited from sixty schools (62.6% government schools) with equal gender distribution. The overall median (interquartile range) BLL was 8.8 (4.8, 16.4) µg/dl. The highest median (interquartile range) BLL was in Manipal 30.6 (23.0, 46.7) and lowest in Dibrugarh 4.8 (3.2, 7.0). Overall, 82.5% of participants had BLL above ≤4 µg/dl. Significant negative correlation was observed between BLL and SES (correlation= -0.24, p <0.001), anthropometric indicators (correlation= -0.11, p <0.001), hemoglobin level (correlation= -0.045, p = 0.03) and multivariate regression model showed association with gender, SES and anthropometric indicators.

CONCLUSIONS

BLL are elevated in urban school going children and there is intercity variation. Hence, urgent focus is needed to reduce exposure to lead in India.

Temporal Changes in Lead and Cadmium Levels in Amanita muscaria Samples Collected in Poland

In recent years, an increasing popularity of consuming Amanita muscaria has been observed in Poland, aimed at reducing various medical symptoms. However, there is a lack of data regarding the impact of variations in the content of toxic elements, such as cadmium (Cd) and lead (Pb), in Amanita muscaria collected during late summer and mid-fall. The aim of this study was to determine the concentrations of Pb and Cd in Amanita muscaria samples collected at different times of the year, compare the concentrations of these elements in samples with and without cap skin, and compare the obtained values to permissible limits in dietary supplements. A total of 44 Amanita muscaria samples were collected during three different harvesting periods (August, September, and October 2023) from Puszcza Biała, located approximately 80 km from Warsaw. The mushrooms were subjected to mineralization using concentrated nitric acid and hydrogen peroxide, followed by the determination of Pb and Cd concentrations using an atomic absorption spectrometer. Significant statistical differences were found in the Pb concentrations of samples collected in three different seasons (η2 = 0.67, p < 0.001), with the concentration increasing progressively, reaching its highest value in October. Similarly, the Cd concentration also increased in the later collections, although the effect of time was weaker (η2 = 0.13, p = 0.03). No significant differences were observed in Pb and Cd concentrations between samples with and without cap skin. The average Cd concentrations in mushrooms were significantly higher than the permissible levels in dietary supplements; they were four times higher in August (p < 0.001), six times higher in September (p < 0.001), and nine times higher in October (p < 0.001). The Pb concentration in the October samples was close to the permissible limit but did not exceed it in a statistically significant manner (p = 0.85). Due to the high Cd concentrations and potentially hazardous levels of Pb, the consumption of Amanita muscaria carries a significant risk of toxicity, which may lead to serious health hazards, particularly in the context of prolonged exposure.

Health Risk Assessment of Potentially Toxic Metals in Differently Processed Catfish (Clarias gariepinus) from Selected Markets from Abeokuta Southwestern Nigeria

Fish is a significant source of animal protein for humans; however, it has a tendency to bioaccumulate toxicants from the environment. The present study assessed the health risks associated with potential toxic metals (PTMs) in differently processed catfish (Clarias gariepinus) from four markets in Abeokuta metropolis, southwestern Nigeria. A total of 60 samples were collected and analyzed for PTMs using an Atomic Absorption Spectrophotometer. The health risk assessment was evaluated based on the hazard quotient (HQ), hazard index (HI), and cancer risk (CR). Iron concentrations ranged from 8.10 ± 6.80 to 70.7 ± 30.8 mg/kg, making it the highest measured metal in the fish samples. The mean chromium (Cr) levels (0.25 ± 0.25 to 28.4 ± 14.5 mg/kg), and lead concentrations (< 0.08 to 0.80 ± 0.70 mg/kg) exceeded the permissible limits set by the joint FAO/WHO, in most of the differently processed fish samples. Principal component analysis identified two likely sources of metal contamination in the fish samples as pond/river runoff and vehicular emissions. The health risk assessment revealed a HQ for Cr exceeding the permissible limit of 1.0 across all processed catfish consumed by both adults and children. Similarly, the CR values for Cr surpassed the threshold of 1.0 × 10⁻4 in both age groups. Chromium accounted for 43% to 98% of the contributions to both carcinogenic and non-carcinogenic health risks. The findings indicated that children are more susceptible to the adverse health effects of PTMs than adults through the consumption of variously processed catfish.

Toxic metals and other elements in Svalbard reindeer: Establishing baselines and assessing non-invasive sampling for biomonitoring

Pollutants emitted from all over the world may reach pristine areas, such as the Arctic. The Svalbard reindeer (Rangifer tarandus platyrhynchus) has been the subject of a few studies reporting toxic metal concentrations. However, these studies either date back a few decades or exclusively used non-invasive samples (e.g., faeces and fur), leaving us without an updated assessment of the concentrations in internal tissues and target organs. This study is the first to present the concentrations of the toxic metals mercury (Hg), cadmium (Cd), and lead (Pb) in both invasive and non-invasive samples from female Svalbard reindeer. The highest concentrations of both Hg and Cd were found in the kidneys (x̄=0.68 μg/g and 16.3 μg/g dw, respectively). The highest concentration of Pb was found in faeces (x̄=2.62 μg/g dw), followed by liver (x̄=0.28 μg/g dw). While both Cd and Pb concentrations in Svalbard reindeer were comparable to levels reported in other reindeer subspecies or circumpolar wildlife, Hg concentrations were lower than those reported in most other studies on reindeer. Conversely, Hg levels in Svalbard reindeer were still higher than levels reported in wildlife from central Europe, demonstrating the influence of long-range transport of Hg to the Arctic. By comparing the toxic metal concentrations in different sample types, we confirm a relationship between Hg concentrations in invasive and non-invasive samples, with faeces being the most promising proxy for soft tissue Hg concentrations. Consequently, future Hg biomonitoring efforts may be carried out with relatively simple sampling procedures and without sacrificing Svalbard reindeer.

From contamination to detection: The growing threat of heavy metals

Heavy metals like lead, mercury, cadmium, and arsenic are environmental pollutants that accumulate in ecosystems and pose significant health risks to humans and wildlife, primarily through food chain contamination where plants absorb heavy metals, affecting their growth and threatening consumer health. Cognitive and cardiovascular functions are particularly affected by exposure to heavy metals even at low concentrations through the induction of oxidative stress. Various analytical techniques are used in measuring heavy metals in different environmental and biological samples. The atomic absorption spectroscopy (AAS) offers low cost, simplicity, and portability but lacks sensitivity for certain metals. Although more sensitive, the high cost of inductively coupled plasma mass spectrometry (ICP-MS) may limit laboratory accessibility. The inductively coupled plasma with atomic emission spectrometry (ICP-AES) is known for its broad dynamic linear range and ability to identify minute variations in concentration. Atomic fluorescence spectrometry (AFS) is considered a powerful tool for quantifying heavy metals due to its high sensitivity, low detection limits, and wide linear range. The current article reviews heavy metal pollution's impact on health and spectrometric techniques for the detection of these contaminants. This may help efforts of international, and regional policies towards preventing this health hazard problem.

Trace level detection of Pb2+ ion using organic ligand as fluorescent-on probes in aqueous media

In this study, an optical sensor, JA/(2,6-di((E)-benzylidene)cyclohexan-1-one), was synthesized and characterized using 1H NMR and FT-IR spectroscopy. The sensor exhibited high efficiency and selectivity in detecting Pb2+ ions, even in the presence of potential interfering ions such as Mn2+, Cu2+, Co2+, Cr3+, Ni2+, Ce3+, Hg2+, and Cd2+ in aqueous solutions. The interaction of JA with Pb2+ resulted in a significant enhancement of fluorescence intensity, suggesting the formation of a stable complex. A 2:1 binding ratio between JA and Pb2+ was confirmed through fluorometric analysis, absorption spectra, and theoretical calculations (DFT). The association constant for the complex was calculated to be 3 × 106 M-2. The sensor demonstrated high sensitivity towards Pb2+ with a detection limit of 5 × 10-7 M. Additionally, JA was successfully reused by applying EDTA to release Pb2+ from the sensor. Real sample analysis under optimized conditions of pH, time, and concentration of JA and Pb2+ further validated the practical applicability of the sensor.

X-Ray Shielding Polymer Based on Sequential Polycondensation of BiPh3 and Carboxylic Acids and Radical Polymerization

Transparent X-ray shielding polymer films were developed by bulk photo copolymerization of in situ prepared bismuth carboxylate prepolymers with polymerizable exomethylene moieties and N,N-dimethylacrylamide (DMAA). The bismuth-containing prepolymers were prepared via the polycondensation of BiPh3, 2-octenylsuccinic acid (OSA), and itaconic acid (IA) bearing an exomethylene group for polymerization. OSA was a chain extender by intermolecular condensation and a stopper by intramolecular cyclization to inhibit cross-linkage. The resulting photocured films exhibit high visible-light transparency and high nD, reaching 1.57. The X-ray shielding ability increased with the bismuth content and reached an aluminum equivalent of 0.80.

A Novel Pb2+and Cys Induced Switch Off-On Strategy and Its Application in Detection Based on the Platform of N-Methylmesoporphyrin IX Fluorescence Being Amplied by G-Quadruplex

Lead (Pb2+) ions give an imminent danger since they have been known to cause persistent damage to humans, plants, and animals, even at low concentrations, and cysteine (Cys) elevated levels are critical indicators for many diseases. Therefore, their detection is critical in pharmaceutical and environmental samples. This study tailored an innovative fluorescence switch off-on assay to detect Pb2+ and Cys based on the amplification of G-quadruplex (G-4) to N-methylmesoporphyrin IX (NMM). This assay operates on the fluorescence of NMM serving as a signal reporter which could be enhanced by an adenine-guanine-rich probes G-4. Initially, the fluorescence of NMM was increased after binding with G-4 and Pb2+ and effectively quenching fluorescence without altering the structure of G-4. As it was proved by Circular dichroism (CD). The number of binding sites for Pb2+ per NMM was determined to be 0.80 with a binding constant of 1.9 × 104 mol /L. The presence of Cys may disrupt the interaction between Pb2+ and G-4/NMM due to its stronger binding affinity towards Pb2+ leading to high fluorescence recovery.The assay demonstrated the capability to detect Pb2⁺ within a concentration range of 0.4 to 1.6 μM, achieving a high correlation coefficient (R2 = 0.985). with the detection limit of 0.45 μM was established. Similarly, Cys was effectively detected across a range of 1 to 6 μM, possessing correlation (R2 = 0.973) with a detection limit of 1.51 μM, further confirming that the detection limit is not influenced by the starting point of the linear range. The assay detected these compounds among various other amino acids and heavy metals. Our approach is simple and innovative, enabling the accurate determination of Pb2+ and Cys concentrations in soil and medicinal samples, highlighting its potential in practical diagnostic and environmental applications.

PlomBOX: a low cost bioassay for the sensitive detection of lead in drinking water

This paper reports the design of a biosensor for sensitive, low-cost measurement of lead in drinking water. The biosensor uses a genetically-modified strain of Escherichia coli, which serves as both signal amplifier and reporter of lead in water, measured via colour change. We developed the PlomBOX measurement platform to image this colour change and we demonstrate its capability to detect concentrations as low as the World Health Organisation upper limit for drinking water of 10 ppb. Our approach does not require expensive infrastructure or expert operators, and its automated sensing, detection and result visualisation platform is user-friendly and robust compared to existing lead biosensors-critical features to enable measurement by non-experts at the point of use.

The influence of contemporary and emerging factors on blood lead concentrations among young males in conflict with the law: a case study from a middle-income country

Introduction

Scientific evidence shows that contemporary and emerging factors contribute to high blood lead concentrations in different populations. The study aimed to determine blood lead concentrations and risk factors associated with high blood lead concentrations among young males in conflict with the law.

Methods

A cross-sectional analytical study was conducted among 192 conveniently selected participants from two youth secure (correctional) facilities in Gauteng Province, South Africa.

Results

The study's overall blood lead concentration median was 3.30 μg/dl, ranging from 0.85 to 48.11 μg/dl. Young males born outside of South Africa (median = 8.78 μg/dl) and in villages (median = 4.95 μg/dl), working before coming to the facility (median = 5.23 μg/dl) and involvement in illegal mining (median = 9.00 μg/dl) had high blood lead concentrations in this study. Contemporary and emerging risk factors such as being born outside the country (AOR: 3.10, 95%CI: 1.01-1.88), involvement in illegal mining activities (AOR: 1.36, 95%CI: 1.14-1.91) and staying in a house with peeling paint on the outside (AOR: 2.26, 95%CI: 1.12-4.30) were found to influence blood lead concentration.

Discussion

The study findings show that contemporary (co-existing) and emerging factors influence blood lead concentrations. Therefore, there is a need to investigate these factors further in communities that may be affected. Lastly, there is a need for a holistic approach involving multiple sectors to introduce human lead concentration screening and preventive programmes.

Heavy metals exposure and Alzheimer's disease: Underlying mechanisms and advancing therapeutic approaches

Heavy metals such as lead, cadmium, mercury, and arsenic are prevalent in the environment due to both natural and anthropogenic sources, leading to significant public health concerns. These heavy metals are known to cause damage to the nervous system, potentially leading to a range of neurological conditions including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), and attention-deficit hyperactivity disorder (ADHD). The present study examines the complex relationship between heavy metal exposure and AD, focusing on the underlying mechanisms of toxicity and potential therapeutic approaches. This review article highlights how these metals can impair brain function through mechanisms such as oxidative stress, inflammation, and neurotransmitter disruption, ultimately contributing to neurodegenerative diseases like AD. It also addresses the challenges in diagnosing heavy metal-induced cognitive impairments and emphasizes the need for further research to explore effective treatment strategies and preventive measures against heavy metal exposure.

Heavy metals: toxicity and human health effects

Heavy metals are naturally occurring components of the Earth's crust and persistent environmental pollutants. Human exposure to heavy metals occurs via various pathways, including inhalation of air/dust particles, ingesting contaminated water or soil, or through the food chain. Their bioaccumulation may lead to diverse toxic effects affecting different body tissues and organ systems. The toxicity of heavy metals depends on the properties of the given metal, dose, route, duration of exposure (acute or chronic), and  extent of bioaccumulation. The detrimental impacts of heavy metals on human health are largely linked to their capacity to interfere with antioxidant defense mechanisms, primarily through their interaction with intracellular glutathione (GSH) or sulfhydryl groups (R-SH) of antioxidant enzymes such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione reductase (GR), and other enzyme systems. Although arsenic (As) is believed to bind directly to critical thiols, alternative hydrogen peroxide production processes have also been postulated. Heavy metals are known to interfere with signaling pathways and affect a variety of cellular processes, including cell growth, proliferation, survival, metabolism, and apoptosis. For example, cadmium can affect the BLC-2 family of proteins involved in mitochondrial death via the overexpression of antiapoptotic Bcl-2 and the suppression of proapoptotic (BAX, BAK) mechanisms, thus increasing the resistance of various cells to undergo malignant transformation. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important regulator of antioxidant enzymes, the level of oxidative stress, and cellular resistance to oxidants and has been shown to act as a double-edged sword in response to arsenic-induced oxidative stress. Another mechanism of significant health threats and heavy metal (e.g., Pb) toxicity involves the substitution of essential metals (e.g., calcium (Ca), copper (Cu), and iron (Fe)) with structurally similar heavy metals (e.g., cadmium (Cd) and lead (Pb)) in the metal-binding sites of proteins. Displaced essential redox metals (copper, iron, manganese) from their natural metal-binding sites can catalyze the decomposition of hydrogen peroxide via the Fenton reaction and generate damaging ROS such as hydroxyl radicals, causing damage to lipids, proteins, and DNA. Conversely, some heavy metals, such as cadmium, can suppress the synthesis of nitric oxide radical (NO·), manifested by altered vasorelaxation and, consequently, blood pressure regulation. Pb-induced oxidative stress has been shown to be indirectly responsible for the depletion of nitric oxide due to its interaction with superoxide radical (O2·-), resulting in the formation of a potent biological oxidant, peroxynitrite (ONOO-). This review comprehensively discusses the mechanisms of heavy metal toxicity and their health effects. Aluminum (Al), cadmium (Cd), arsenic (As), mercury (Hg), lead (Pb), and chromium (Cr) and their roles in the development of gastrointestinal, pulmonary, kidney, reproductive, neurodegenerative (Alzheimer's and Parkinson's diseases), cardiovascular, and cancer (e.g. renal, lung, skin, stomach) diseases are discussed. A short account is devoted to the detoxification of heavy metals by chelation via the use of ethylenediaminetetraacetic acid (EDTA), dimercaprol (BAL), 2,3-dimercaptosuccinic acid (DMSA), 2,3-dimercapto-1-propane sulfonic acid (DMPS), and penicillamine chelators.

Assessing the life cycle impacts of the remediation of shooting ranges in peatland environments

This paper aims to expand knowledge of the potential environmental impacts associated with the remediation of shooting ranges in peatland environments. While the remediation of these sites currently requires the excavation and disposal of contaminated soil to meet local environmental quality guideline values, there is a growing recognition that this remediation process causes substantial environmental impacts. A life cycle assessment (LCA) was undertaken to identify the life cycle impacts and potential mitigation measures to reduce them. The results showed that for the majority of impact categories, downstream landfilling processes dominated impacts; in particular, substantial greenhouse gas emissions were associated with the decomposition of carbon-rich peat soil caused by excavation and removal (119 t CO2 equivalents, representing 67.8 % of the life cycle emissions). In addition, gravel materials used for road building was important to several impact categories. The greenhouse gas mitigation potential was 17 % and included the use of renewable fuels, electric excavators, local site equipment, material selection and the reuse of materials. While the impacts from site infrastructure and excavation may be reduced through appropriate planning and management, the greenhouse gas emissions impact from excavating carbon-rich soil is proportional to the excavated soil volume. Therefore, the acceptability of these impacts should be carefully evaluated against the benefits of reduced contaminant leaching into the receiving environment.