Lead-based paint remains a major public health concern: A critical review of global production, trade, use, exposure, health risk, and implications

Heavy metal ion sensing strategies using fluorophores for environmental remediation

The main aim of this review is to provide a holistic summary of the latest advances within the research area focusing on the detection of heavy metal ion pollution, particularly the sensing strategies. The review explores various heavy metal ion detection approaches, encompassing spectrometry, electrochemical methods, and optical techniques. Numerous initiatives have been undertaken in recent times in response to the increasing demand for fast, sensitive, and selective sensors. Notably, fluorescent sensors have acquired prominence owing to the numerous advantages such as good specificity, reversibility, and sensitivity. Further, this review also explores the advantages of various nanomaterials employed in sensing heavy metal ions. In this regard, exclusive emphasis is placed on fluorescent nanomaterials based on organic dyes, quantum dots, and fluorescent aptasensors for metal ion removal from aqueous systems, and to identify the fate of heavy metal ions in the natural environment.

Indoor paint life cycle particle release: Safer-by-design products and the importance of choosing the right formula

In 2020, the European Commission published a regulation that states all producers of white paints containing titanium dioxide (TiO2) must provide a warning label on their products. Exposure during the production and application of products containing TiO2 can be harmful, and therefore these products must be labeled as "may cause cancer." The paint industry is a major user of TiO2 pigment. This study focuses on pigment release from three TiO2-based paints and discusses the effect of paint formulation, more precisely the Pigment Volume Concentration (PVC), to predict TiO2 pigment release from the paints during a simulated use phase and at the end of life (EoL). The use phase considered mild abrasion of painted panels that simulated cleaning or touching. The EoL phase was studied using leaching tests simulating landfill disposal. TiO2 release during both activities was evident with a high discrepancy between the three paints. While dry rubbing was similar for all paints, activities involving water present a high release link to paint matrix degradation. The paint pigment volume concentration and the paint permeability determines the TiO2 release during wet rubbing and leaching. This work represents an attempt to identify the paint permeability as a matrix-related parameter to predict TiO2 release and a way to use of this parameter to develop safer products.

Impacts of phosphorus amendments on legacy soil contamination from lead-based paint on a California, USA university campus

Lead (Pb) is one of the most common heavy metal urban soil contaminants with well-known toxicity to humans. This incubation study (2-159 d) compared the ability of bone meal (BM), potassium hydrogen phosphate (KP), and triple superphosphate (TSP), at phosphorus:lead (P:Pb) molar ratios of 7.5:1, 15:1, and 22.5:1, to reduce bioaccessible Pb in soil contaminated by Pb-based paint relative to control soil to which no P amendment was added. Soil pH and Mehlich 3 bioaccessible Pb and P were measured as a function of incubation time and amount and type of P amendment. XAS assessed Pb speciation after 30 and 159 d of incubation. The greatest reductions in bioaccessible Pb at 159 d were measured for TSP at the 7.5:1 and 15:1 P:Pb molar ratios. The 7.5:1 KP treatment was the only other treatment with significant reductions in bioaccessible Pb compared to the control soil. It is unclear why greater reductions of bioaccessible Pb occurred with lower P additions, but it strongly suggests that the amount of P added was not a controlling factor in reducing bioaccessible Pb. This was further supported because Pb-phosphates were not detected in any samples using XAS. The most notable difference in the effect of TSP versus other amendments was the reduction in pH. However, the relationship between increasing TSP additions, resulting in decreasing pH and decreasing Pb bioaccessibility was not consistent. The 22.5:1 P:Pb TSP treatment had the lowest pH but did not significantly reduce bioaccessible Pb compared to the control soil. The 7.5:1 and 15:1 P:Pb TSP treatments significantly reduced bioaccessible Pb relative to the control and had significantly higher pH than the 22.5:1 P:Pb treatment. Clearly, impacts of P additions and soil pH on Pb bioaccessibility require further investigation to decipher mechanisms governing Pb speciation in Pb-based paint contaminated soils.

Assessment of the migration characteristics and source-oriented health risks of heavy metals in the soil and groundwater of a legacy contaminated by the chlor-alkali industry in central China

The chlor-alkali industry (CAI) is crucial for global chemical production; however, its operation has led to widespread heavy metal (HM) contamination at numerous sites, which has not been thoroughly investigated. This study analysed 122 soil and groundwater samples from a typical CAI site in Kaifeng, China. Our aim was to assess the ecological and health risks, identify the sources, and examine the migration characteristics of HMs at this site using Monte Carlo simulation, absolute principal component score-multiple linear regression (APCS-MLR), and the potential environmental risk index (Ei). Our findings revealed that the exceedance rates for Cd, Pb, Hg, and Ni were 71.96%, 45.79%, 49.59%, and 65.42%, respectively. Mercury (Hg) displayed the greatest coefficient of variation across all the soil layers, indicating a significant anthropogenic influence. Cd and Hg were identified as having high and extremely high potential environmental risk levels, respectively. The spatial distributions of the improved Nemerow index (INI), total ecological risk (Ri), and HM content varied considerably, with the most contaminated areas typically associated with the storage of raw and auxiliary materials. Surface aggregation and significant vertical transport were noted for HMs; As and Ni showed substantial accumulation in subsoil layers, severely contaminating the groundwater. Self-organizing maps categorized the samples into two different groups, showing strong positive correlations between Cd, Pb, and Hg. The APCS-MLR model suggested that industrial emissions were the main contributors, accounting for 60.3% of the total HM input. Elevated hazard quotient values for Hg posed significant noncarcinogenic risks, whereas acceptable levels of carcinogenic risk were observed for both adults (96.60%) and children (97.83%). This study significantly enhances historical CAI pollution data and offers valuable insights into ongoing environmental and health challenges.

Probabilistic risk assessment of dietary exposure to lead in residents of Guangzhou, China

Lead and its compounds can have cumulative harmful effects on the nervous, cardiovascular, and other systems, and especially affect the brain development of children. We collected 4918 samples from 15 food categories in 11 districts of Guangzhou, China, from 2017 to 2022, to investigate the extent of lead contamination in commercial foods and assess the health risk from dietary lead intake of the residents. Lead was measured in the samples using inductively coupled plasma mass spectrometry. Dietary exposure to lead was calculated based on the food consumption survey of Guangzhou residents in 2011, and the health risk of the population was evaluated using the margin of exposure (MOE) method. Lead was detected in 76.5% of the overall samples, with an average lead content of 29.4 µg kg-1. The highest lead level was found in bivalves. The mean daily dietary lead intakes were as follows: 0.44, 0.34, 0.25, and 0.28 µg kg-1 body weight (bw) day-1 for groups aged 3-6, 7-17, 18-59, and ≥ 60 years, respectively. Rice and rice products, leafy vegetables, and wheat flour and wheat products were identified as the primary sources of dietary lead exposure, accounting for 73.1%. The MOE values demonstrated the following tendency: younger age groups had lower MOEs, and 95% confidence ranges for the groups aged 3-6 and 7-17 began at 0.6 and 0.7, respectively, indicating the potential health risk of children, while those for other age groups were all above 1.0. Continued efforts are needed to reduce dietary lead exposure in Guangzhou.

How does formal and informal industry contribute to lead exposure? A narrative review from Vietnam, Uruguay, and Malaysia

INTRODUCTION

Lead industries are one of the major sources of environmental pollution and can affect human through different activities, including industrial processes, metal plating, mining, battery recycling, etc. Although different studies have documented the various sources of lead exposure, studies highlighting different types of industries as sources of environmental contamination are limited. Therefore, this narrative review aims to focus mainly on lead industries as significant sources of environmental and human contamination.

CONTENT

Based on the keywords searched in bibliographic databases we found 44 relevant articles that provided information on lead present in soil, water, and blood or all components among participants living near high-risk areas. We presented three case scenarios to highlight how lead industries have affected the health of citizens in Vietnam, Uruguay, and Malaysia.

SUMMARY AND OUTLOOK

Factories conducting mining, e-waste processing, used lead-acid battery recycling, electronic repair, and toxic waste sites were the primary industries for lead exposure. Our study has shown lead exposure due to industrial activities in Vietnam, Uruguay, Malaysia and calls for attention to the gaps in strategic and epidemiologic efforts to understand sources of environmental exposure to lead fully. Developing strategies and guidelines to regulate industrial activities, finding alternatives to reduce lead toxicity and exposure, and empowering the public through various community awareness programs can play a crucial role in controlling exposure to lead.

Trust and subjective knowledge influence perceived risk of lead exposure

Lead exposure is a persistent environmental hazard that poses risks to human health. But motivating protective action is challenging with this low visibility hazard whose health effects are often subtle and chronic. Higher risk perception is generally associated with taking protective measures, so public health efforts prioritize risk messaging. Yet, little is known about perceptions of lead exposure risk among the U.S. public. Using cross-sectional data from a national survey of 1035 U.S. residents, we measured the role of trust in government management of lead and subjective knowledge about lead as predictors of perceived risk of lead exposure, controlling for demographic and environmental factors. We also assessed if subjective knowledge moderated the relationship between trust and perceived risk. Our results reveal positive relationships between trust in government management of lead, subjective knowledge about lead, and risk perception, which we attribute in part to the important role government agencies play in secondary prevention, or communicating the risks of environmental lead exposure. We also found that younger people and people living in a house built before lead paint regulations passed in 1978 perceived higher lead risks. Our findings suggest that general communication about lead risks should aim to increase people's subjective knowledge in a consistent and balanced way that improves trust in government messengers.

Mapping Blood Lead Levels in China during 1980-2040 with Machine Learning

Lead poisoning is globally concerning, yet limited testing hinders effective interventions in most countries. We aimed to create annual maps of county-specific blood lead levels in China from 1980 to 2040 using a machine learning model. Blood lead data from China were sourced from 1180 surveys published between 1980 and 2022. Additionally, regional statistical figures for 15 natural and socioeconomic variables were obtained or estimated as predictors. A machine learning model, using the random forest algorithm and 2973 generated samples, was created to predict county-specific blood lead levels in China from 1980 to 2040. Geometric mean blood lead levels in children (i.e., age 14 and under) decreased significantly from 104.4 μg/L in 1993 to an anticipated 40.3 μg/L by 2040. The number exceeding 100 μg/L declined dramatically, yet South Central China remains a hotspot. Lead exposure is similar among different groups, but overall adults and adolescents (i.e., age over 14), females, and rural residents exhibit slightly lower exposure compared to that of children, males, and urban residents, respectively. Our predictions indicated that despite the general reduction, one-fourth of Chinese counties rebounded during 2015-2020. This slower decline might be due to emerging lead sources like smelting and coal combustion; however, the primary factor driving the decline should be the reduction of a persistent source, legacy gasoline-derived lead. Our approach innovatively maps lead exposure without comprehensive surveys.

Mechanistic investigation of Pb2+ adsorption on biochar modified with sodium alginate composite zeolitic imidazolate framework-8

For the serious situation of heavy metal pollution, the use of cheap, clean, and efficient biochar to immobilize heavy metals is a good treatment method. In this paper, SA@ZIF-8/BC was prepared for the adsorption of Pb2+ in solution using sodium alginate (SA) and zeolitic imidazolate framework-8 (ZIF-8) modified corn cob biochar. The results showed that the specific surface area of modified biochar was greatly improved, with good adsorption capacity for Pb2+, strong anti-interference ability, and good economy. At the optimal adsorption pH of 5, the adsorption model of Pb2+ by SA@ZIF-8/BC was more consistent with the pseudo-second-order kinetic model and Langmuir isotherm model. This indicates that the adsorption of Pb2+ by SA@ZIF-8/BC is chemisorption and monolayer adsorption. The maximum adsorption of modified biochar was 300 mg g-1, which was 2.38 times higher than that of before modified BC (126 mg g-1). The shift in binding energy of functional groups before and after adsorption of SA@ZIF-8/BC was studied by XPS, and it was found that hydroxyl and carboxyl groups played an important role in the adsorption of Pb2+. It was demonstrated that this novel adsorbent can be effectively used for the treatment of Pb pollution in wastewater.

Characteristics, source analysis, and health risk assessment of potentially toxic elements pollution in soil of dense molybdenum tailing ponds area in central China

The issue of potentially toxic elements (PTEs) contamination of regional soil caused by mining activities and tailings accumulation has attracted wide attention all over the world. The East Qinling is one of the three main molybdenum mines in the world, and the concentration of PTEs such as Hg, Pb and Cu in the slag is high. Quantifying the amount of PTEs contamination in soil and identifying potential sources of contamination is vital for soil environmental management. In the present investigation, the pollution levels of 8 PTEs in the Qinling molybdenum tailings intensive area were quantitatively identified. Additionally, an integrated source-risk method was adopted for resource allocation and risk assessment based on the PMF model, the ecological risk, and the health risk assessment model. The mean concentrations of Cu, Ni, Pb, Cd, Cr, Zn, As, and Hg in the 80 topsoil samples ranged from 0.80 to 13.38 times the corresponding background values; notably high levels were observed for Pb and Hg. The source partitioning results showed that PTEs were mainly affected by four pollution sources: natural and agricultural sources, coal-burning sources, combined transport and mining industry sources, and mining and smelting sources. The health risk assessment results revealed that the risks of soil PTEs for adults are acceptable, while the risks for children exceeded the limit values. The obtained results will help policymakers to obtain the sources of PTEs of tailing ponds intensive area. Moreover, it provides priorities for the governance of subsequent pollution sources and ecological restoration.

Near-field exposures and human health impacts for organic chemicals in interior paints: A high-throughput screening

Interior paints contain organic chemicals that might be harmful to painters and building residents. This study aims to develop a high-throughput approach to screen near-field human exposures and health impacts related to organic chemicals in interior paints. We developed mass balance models for both water- and solvent-based paints, predicting emissions during wet and dry phases. We then screened exposures and risks, focusing on Sri Lanka where residential houses are frequently repainted. These models accurately predict paint drying time and indoor air concentrations of organic chemicals. Exposures of both painter and household resident were estimated for 65 organic chemicals in water-based and 26 in solvent-based paints, considering 12 solvents. Chemicals of concerns (CoCs) were identified, and maximum acceptable chemical contents (MACs) were calculated. Water-based paints generally pose lower health risks than solvent-based paints but might contain biocides of high concern. The total human health impact of one painting event on all household adults ranges from 1.5 × 10-3 to 2.1 × 10-2 DALYs for solvent-based paints, and from 4.1 × 10-4 to 9.5 × 10-3 DALYs for water-based paints. The present approach is a promising way to support the formulation of safer paint, and is integrated in the USEtox scientific consensus model for use in life cycle assessment, chemical substitution and risk screening.

Individual and combined impact of microplastics and lead acetate on the freshwater shrimp (Caridina fossarum): Biochemical effects and physiological responses

Microplastics and heavy metals pollution is recognised as a major problem affecting aquatic ecosystems. For this reason, this study aims to assess the toxicity of different concentrations of polyethylene microplastics (PE-MPs) (0.0, 500, and 1000 μg L-1) with a mean size of 15-25 μm and lead acetate Pb(C2H3O2)2 (0.0, 2.5, and 5 mg L-1), both individually and in combination, through the exposure of the freshwater grass shrimp, Caridinia fossarum for 15 days, focusing on microplastic interaction with co-occurring contaminants. After being exposed to both contaminants, either individually or in combination, significant alterations in numerous biochemical markers were observed. Specifically, exposure to lead acetate alone resulted in significant changes across ALP, AST, ALT, LDH, GGT, and BChE enzyme activity levels indicating hepatotoxicity and neurotoxicity. Also, Pb exposure led to alterations in total antioxidant capacity, MDA, total lipids, and glycogen contents, signalling the onset of oxidative stress. Exposure to PE-MPs alone led to changes in ALP, LDH, GGT, and BChE enzyme levels, and in MDA, total lipids, and glycogen samples' contents. Remarkably, the study observed increased bioaccumulation of lead acetate in samples treated with the combination, emphasizing the synergistic impact of PE-MPs on the toxicity of lead acetate. This synergy was also evident in AST and ALT enzyme activity levels and MDA contents. This underscores the necessity for measures to address both microplastic pollution and heavy metal contamination, taking into account the synergistic behaviour of MPs in the presence of concurrent contaminants.

Firearm-Related Lead Exposure and Child Lead Levels in the United States, 2012-2018

OBJECTIVE

To determine if firearm ownership is positively related to elevated child lead levels at a state-level, even when accounting for other sources of lead.

STUDY DESIGN

For this cross-sectional ecological study, we investigated whether household firearm ownership rates (a proxy for firearm-related lead exposure) was associated with the prevalence of elevated child blood lead levels in 44 US States between 2012 and 2018. To account for potential confounding, we adjusted for other known lead exposures, poverty rate, population density, race, and calendar year. To address missing data, we used multiple imputation by chained equations.

RESULTS

Prevalence of elevated child blood lead positively correlated with household firearm ownership and established predictors of lead exposure. In fully adjusted negative binomial regression models, child blood lead was positively associated with household firearm ownership and older housing; each IQR (14%) increase in household firearm ownership rate was associated with a 41% higher prevalence of childhood elevated blood lead (prevalence ratio: 1.41, 95% CI: 1.11-1.79).

CONCLUSION

These data provide state-level evidence that firearms may be an important source of child lead exposure. More research is needed to substantiate this relationship and identify modifiable pathways of exposure at the individual level.

Contamination and Carcinogenic Risks of Lead in Lip Cosmetics in China

There are growing concerns about elevated lead (Pb) levels in lip cosmetics, yet in China, the largest lip cosmetic market, recent Pb contamination in lip cosmetics and associated Pb exposure remain unclear. Here, we measured Pb levels of 29 popular lip cosmetics in China and conducted the bioaccessibility-corrected carcinogenic risk assessments and sensitivity analysis regarding Pb exposure for consumers using Monte Carlo simulation. The Pb concentrations of collected samples ranged from undetectable (< 0.05 µg/kg) to 0.21 mg/kg, all of which were well below the Pb concentration limit set for cosmetics in China (10 mg/kg). The 50th percentile incremental lifetime cancer risk (ILCR) of Pb in Chinese cosmetics (1.20E-07) was below the acceptable level (1E-06), indicating that the application of lip cosmetics and subsequent Pb exposure does not pose carcinogenic risks to consumers in most cases. The results of this study provide new insights into understanding the Pb risk in lip cosmetics.

Health Risk Assessment of Heavy Metals in Indoor Household Dust in Urban and Rural Areas of Chiang Mai and Lamphun Provinces, Thailand

Indoor exposure to heavy metals poses human health risks worldwide, but study reports from Thailand are still limited, particularly in rural and urban areas. We measured the heavy metals in a hundred indoor household dust samples collected from urban and rural areas in Chiang Mai and Lamphun provinces and found a significantly higher concentration of As in rural areas and Cd in urban areas with industrial activities. The source identification of the heavy metals showed significant enrichment from traffic emissions, paint, smoking, and mixed sources with natural soil. From health risk assessment models, children were more vulnerable to noncarcinogenic risks (HI = 1.45), primarily via ingestion (HQ = 1.39). Lifetime cancer risks (LCRs) due to heavy metal exposure were found in adults (LCR = 5.31 × 10-4) and children (LCR = 9.05 × 10-4). The cancer risks from As were higher in rural areas via ingestion, while Cr and Ni were higher in urban areas via inhalation and ingestion, respectively. This study estimated that approximately 5 out of 10,000 adults and 9 out of 10,000 children among the population may develop cancer in their lifetime from exposure to indoor heavy metals in this region.

Assessment of source-oriented health risk associated with the oral ingestion of heavy metals in dust within an iron/steel smelting-affected area of the North China Plain

Heavy metals (HMs) from iron/steel smelting activities pose notable risks to human health, especially to those living around industrial facilities of North China Plain, the base of China's steel production. In this study, 78 outdoor windowsill dust samples were collected around a large-scale iron/steel smelter with more than 65 years of production history in the western North China Plain. Nine HMs were analysed to comprehensively assess the health risks by integrating Monte Carlo simulation, oral bioaccessibility, and source apportionment. Results showed serious pollution with Cd, Pb, and Zn based on their geo-accumulation index values and concentrations. Four potential sources including industrial sources (49.85%), traffic sources (21.78%), natural sources (20.58%), and coal combustion (7.79%) were quantitatively identified by multivariate statistical analysis. The oral bioaccessibilities of HMs determined by the physiologically based extraction test ranged from 0.02% to 65.16%. Zn, Mn, Cd, and Pb had higher bioaccessibilities than other HMs. After incorporating oral bioavailability adjustments, noncarcinogenic and carcinogenic risks were significantly reduced, especially for adults. The mean hazard index (HI) for children and adults was below the safety threshold (1.0), whereas the mean of the total carcinogenic risk (TCR) based on HM bioaccessibilities in the gastric phase remained above the acceptable level (1.0E-06) (children: 5.20E-06; adults: 1.16E-06). Traffic sources warranted increased concern as it substantially increased TCR. Cd was identified as the priority pollution in iron/steel smelting areas. Assessing source-oriented health risks associated with oral ingestion exposure can guide the management and control of HM contamination within iron/steel smelting-affected areas.

Gastrointestinal Manifestations of Lead Poisoning: A Brief Report

Gastrointestinal (GI) manifestations of lead poisoning include abdominal pain, constipation, and diarrhea. Depending on the severity of a symptom, surgical consultation is required. The present study aimed to make a comparison between the mean blood lead levels of patients hospitalized for lead toxicity and the various Gl symptoms. A retrospective cross-sectional study was performed in 2020 at Khorshid Hospital, the main regional referral center for poisoned patients (Isfahan, Iran). A total of 82 patients aged ≥18 years who were hospitalized for lead poisoning during 2017-2018 were included in the study. Patients' information was extracted from hospital medical records, including demographic information, clinical manifestations, blood lead levels, and treatment outcome. The mean age of the patients was 48.18±11.9 years, 91.5% were men, and 62.2% suffered from multiple GI symptoms, with abdominal pain being predominant (31.7%). Blood lead levels in patients with multiple GI symptoms were higher than those with only one symptom (P=0.01). Surgical consultation was required in 14.6% of the patients. Multiple GI symptoms were the main predictive factor for blood lead levels above 70 mg/dL (P=0.03, Odds ratio=3.06, 95% CI=1.09-8.61). Given the prevalence of abdominal pain and its association with elevated blood lead levels, differential diagnosis of abdominal pain should include lead toxicity.

Firearm-related lead exposure and pediatric lead levels in Massachusetts: A decade of evidence (2010-2019)

The US has more firearms than any other country in the world and uses lead ammunition almost exclusively. Lead exposure is a significant public health concern and children are at the greatest risk given their exposure to take-home lead. Firearm-related take-home lead exposure may be one of the greatest influences on elevated pediatric blood lead levels. For this ecological and spatial investigation of the relationship between firearm licensure rates as a proxy for firearm-related lead exposure and prevalence of children with blood lead levels ≥5 μg/dL in 351 cities/towns in Massachusetts, we used 10 years of data (2010-2019). We examined this relationship against other known contributors to pediatric lead exposure including old housing stock (lead paint/dust), occupations, and lead in water. Pediatric blood lead levels were positively correlated with licensure, poverty, and certain occupations and negatively correlated with lead in water and police or firefighter employment. Firearm licensure was a major significant predictor of pediatric blood lead alone (β = 0.13; 95% CI, 0.10, 0.17) and across all regression models. The final model predicted over half the variation in pediatric blood lead (Adjusted R2 = 0.51). Negative binomial analysis found cities/towns with more firearms had higher pediatric blood lead levels (highest quartile fully adjusted prevalence ratio ((aPR) = 1.18; 95% CI, 1.09, 1.30) with a significant increase in pediatric blood lead per increase in firearms (p < 0.001). There were no significant spatial effects, suggesting that although there could be other factors impacting elevated pediatric blood lead, they are unlikely to influence spatial associations. Our paper provides compelling evidence of a potential and dangerous link between lead ammunition and child blood lead levels and is the first to do so using multiple years' worth of data. More research is required to substantiate this relationship on the individual-level and into prevention/mitigation.

Past, present and future trends in the remediation of heavy-metal contaminated soil - Remediation techniques applied in real soil-contamination events

Most worldwide policy frameworks, including the United Nations Sustainable Development Goals, highlight soil as a key non-renewable natural resource which should be rigorously preserved to achieve long-term global sustainability. Although some soil is naturally enriched with heavy metals (HMs), a series of anthropogenic activities are known to contribute to their redistribution, which may entail potentially harmful environmental and/or human health effects if certain concentrations are exceeded. If this occurs, the implementation of rehabilitation strategies is highly recommended. Although there are many publications dealing with the elimination of HMs using different methodologies, most of those works have been done in laboratories and there are not many comprehensive reviews about the results obtained under field conditions. Throughout this review, we examine the different methodologies that have been used in real scenarios and, based on representative case studies, we present the evolution and outcomes of the remediation strategies applied in real soil-contamination events where legacies of past metal mining activities or mine spills have posed a serious threat for soil conservation. So far, the best efficiencies at field-scale have been reported when using combined strategies such as physical containment and assisted-phytoremediation. We have also introduced the emerging problem of the heavy metal contamination of agricultural soils and the different strategies implemented to tackle this problem. Although remediation techniques used in real scenarios have not changed much in the last decades, there are also encouraging facts for the advances in this field. Thus, a growing number of mining companies publicise in their webpages their soil remediation strategies and efforts; moreover, the number of scientific publications about innovative highly-efficient and environmental-friendly methods is also increasing. In any case, better cooperation between scientists and other soil-related stakeholders is still required to improve remediation performance.

Metals as toxicants in event-based expedited production of children's jewelry

Globally, the hazardous substance in children's goods is of great concern. Toxic chemicals are potentially harmful to the health and growth of infants and children. Lead (Pb) and cadmium (Cd)-contaminated children's jewelry is widely encountered in many countries. This study aims to determine the concentration of metal toxicants (Pb, Cd, Ni, Cu, Zn, Co, and Fe) in event-based (Independence Day festival) children's jewelry, considering time-limited and fast production products that may compromise the quality and safety parameters during manufacturing. The determinations are for the time-constraint industrial production of children's jewelry in the context of the toxic substances in a variety of base materials used. This is the first time event-based children's jewelry has been monitored and critically assessed for metal contamination. Forty-two samples, including metallic, wooden, textile, rubber, plastic, and paint-coated plastic children's jewelry, were tested. Seventy-four percent of samples detected Pb and Cd in quantifiable amounts. Ni in 71%, Cu in 67%, Co in 43%, and Zn and Fe were detected in 100% samples with quantifiable amounts. Twenty-two ID-CJ samples exceeded the US regulatory limit for Pb and four samples for Cd. However, twenty-nine samples for Pb, eleven for Cd, five for Co, and one for Cu exceeded the EU regulatory limit. The highest concentration of Pb was found in paint-coated plastic jewelry, and the highest Cd was found in metallic jewelry. These results suggest that the potential hazards of event-based children's jewelry deserve the attention of government agencies seeking to limit children's exposure to toxic chemicals. Intergovernmental organizations and individual countries regulate chemicals in consumer products, but a coordinated international approach is lacking. Some continents and countries still lack in regulations for children's products, especially jewelry, and toys.

Negative Impacts of Arsenic on Plants and Mitigation Strategies

Arsenic (As) is a metalloid prevalent mainly in soil and water. The presence of As above permissible levels becomes toxic and detrimental to living organisms, therefore, making it a significant global concern. Humans can absorb As through drinking polluted water and consuming As-contaminated food material grown in soil having As problems. Since human beings are mobile organisms, they can use clean uncontaminated water and food found through various channels or switch from an As-contaminated area to a clean area; but plants are sessile and obtain As along with essential minerals and water through roots that make them more susceptible to arsenic poisoning and consequent stress. Arsenic and phosphorus have many similarities in terms of their physical and chemical characteristics, and they commonly compete to cause physiological anomalies in biological systems that contribute to further stress. Initial indicators of arsenic's propensity to induce toxicity in plants are a decrease in yield and a loss in plant biomass. This is accompanied by considerable physiological alterations; including instant oxidative surge; followed by essential biomolecule oxidation. These variables ultimately result in cell permeability and an electrolyte imbalance. In addition, arsenic disturbs the nucleic acids, the transcription process, and the essential enzymes engaged with the plant system's primary metabolic pathways. To lessen As absorption by plants, a variety of mitigation strategies have been proposed which include agronomic practices, plant breeding, genetic manipulation, computer-aided modeling, biochemical techniques, and the altering of human approaches regarding consumption and pollution, and in these ways, increased awareness may be generated. These mitigation strategies will further help in ensuring good health, food security, and environmental sustainability. This article summarises the nature of the impact of arsenic on plants, the physio-biochemical mechanisms evolved to cope with As stress, and the mitigation measures that can be employed to eliminate the negative effects of As.

Sentinel animals for monitoring the environmental lead exposure: combination of traditional review and visualization analysis

In nature, certain animals share a common living environment with humans, thus these animals have become biomonitors of health effects related to various environmental exposures. As one of the most toxic environmental chemicals, lead (Pb) can cause detriment health effects to animals, plants, and even humans through different exposure pathways such as atmosphere, soil, food, water, and dust, etc. Sentinel animals played an "indicative" role in the researches of environmental pollution monitoring and human health. In order to comprehend the usage of sentinel animals in the indication of environmental Pb pollution and human Pb exposure completely, a combination of traditional review and visualization analysis based on CiteSpace literature was used to review earlier researches in this study. In the first instance, present researches on exposure sources and exposure pathways of Pb were summarized briefly, and then the studies using sentinel animals to monitor environmental heavy metal pollution and human health were combed. Finally, visualization software CiteSpace 5.8.R3 was used to explore and analyze the hotspots and frontiers of lead exposure and sentinel animals researches at home and abroad. The results showed that certain mammals were good indicators for human lead exposure. Sentinel animals had been widely used to monitor the ecological environment and human lead exposure. Among them, the blood lead levels of small mammals, particularly for domestic dogs and cats, had a significant correlation with the blood lead levels of human living in the same environment. It indicated that certain biological indicators in animals can be used as surrogates to monitor human body exposure to heavy metals. This study also explored the challenges and perspectives that may be faced in sentinel animal research, in order to provide a certain theoretical basis and train of thought guidance for future research.

Macroporous honeycomb-like magnesium oxide fabricated as long-life and outstanding Pb(II) adsorbents combined with mechanism insight

The macroporous honeycomb-like MgO (MHM) had been successfully prepared by hard template method using polystyrene (PS) spheres with different particle sizes of about 400, 600, and 800 nm, respectively. The adsorption performance (3700, 3470, and 3087 mg/g) and specific surface areas (64.0, 51.4, and 34.4 m2/g) of MHM materials were inversely proportional to their pore diameters. Among the prepared MHM materials, MHM-400 exhibited the most excellent adsorption performance of 3700 mg/g towards Pb(II) at 25 °C. In this study, the macropore size in MHM played a major role in the adsorption process; Dubinin-Radushkevich (D-R) model further indicated that Pb(II) removal by MHM-400 was dominated by chemical adsorption. The thermodynamic analysis (ΔG0 < 0, ΔH0 > 0, and ΔS0 > 0) revealed that the Pb(II) adsorption was spontaneous and endothermic. After storing for 360 days, the Pb(II) removal efficiency of MHM-400 was still higher than 98.2%, exhibiting ultra-long life for Pb(II) capture. MHM-400 also exhibited high anti-interference ability towards typically coexisting ions (Na+ and K+). According to the density functional theory (DFT) calculation, the Pb could be adsorbed on the top site of the oxygen atom at the surface of the cubic MgO (200) plane; the adsorption energy (Ead) was 0.159 eV. The XRD and FTIR analyses revealed the further formation of Pb3(CO3)2(OH)2 and PbO after Pb(II) adsorption. Furthermore, MHM-400 could effectively remove both Cd(II) and Pb(II) ions from wastewater within 20 min, and the adsorption efficiency achieved > 99%, suggesting that MHM-400 was a potential material for effective Pb(II) removal.

Health risk assessment of heavy metals in road dust from the fourth-tier industrial city in central China based on Monte Carlo simulation and bioaccessibility

Health risks caused by heavy metal (HM) exposure in road dust has attracted extensive attention, but few studies have focused on the health risks of residents living in small- and medium-sized cities with rapid industrialization and urbanization. Thus, 140 road dust samples were collected across Anyang, a typical fourth-tier industrial city in central China, which were analysed for 10 different HMs (Mn, Zn, Pb, V, Cr, As, Cd, Ni, Cu and Co). Monte Carlo simulation and bioaccessibility were used to quantify the health risks of heavy metals comprehensively in road dust. Results revealed a remarkable accumulation of Mn, Zn, Pb, Cd and Cu. According to the Geo-accumulation index and potential ecological risk index, Cd was priority control pollutant. Moreover, 55.0% of the road dust samples reached heavily polluted level, and 52.86% of the samples were at high ecological risk levels. These results illustrated that HM contamination was serious and universal in the road dust of Anyang. The occurrences of HMs were allocated to traffic emissions, natural sources, industrial activities and agricultural activities with contribution rates of 35.4%, 6.0%, 41.6% and 17.0%, respectively. Except for Zn in the gastric phase, all other HMs had relatively low bioaccessibilities in the gastrointestinal system, usually less than 20%. The bioaccessibilities of most HMs were higher in the gastric phase, except for Cr, Ni and Cu, which remained higher in the intestinal phase. The non-carcinogenic risk and carcinogenic risk were remarkably reduced when considering the HM bioaccessibilities in the gastrointestinal system, especially for adults. The outcomes of this paper are valuable for understanding HM contamination in road dust and highlight the importance of risk assessment for populations living in the fourth- and fifth-tier cities.

Demographic and anthropometric characteristics and their effect on the concentration of heavy metals (arsenic, lead, chromium, zinc) in children and adolescents

Background

Biomonitoring is a well-established method for assessing people's exposure to contaminants in the environment. Many non-communicable diseases can be prevented or aggravated by physiologically monitoring heavy metals in biological matrices such as urine, evaluating their association with non-communicable diseases, and attempting to limit exposure to them. The focus of this research was to determine the association between potentially toxic elements (PTE) such as arsenic (As), lead (Pb), chromium (Cr), and zinc (Zn) urine concentrations and anthropometric indices and demographic data in children and adolescents aged 6-18 years in Kerman, Iran.

Methods

106 children and adolescents aged 6-18 years in Kerman were randomly selected. A questionnaire was used to acquire demographic information from the participants' parents. Height, weight, and waist circumference (WC) were all assessed, as well as body mass index (BMI) and BMI Z-score. Induced Coupled Plasma Mass Spectrometry (ICP/MS) was used to quantify As, Pb, Cr, and Zn concentrations in participants' urine.

Results

The geometric mean concentrations were As (38.72 ± 39.30), Pb (19.58 ± 22.91), Cr (1.06 ± 0.28), and Zn (344.72 ± 288.16) μg/creatinine. Boys aged 12-18 years old had higher mean concentration of As than boys aged 6-11 years old (p = 0.019) according to two measurement standards, μg/L, and μg/creatinine, whereas girls had no significant difference. In general, there was a strong association between parental education and metal concentrations of As, Pb, and Cr. As, Pb, and Zn (μg/creatinine) had a significant positive association with BMI z-score and BMI. As, Pb, and Zn metals were shown to have a substantial positive association (p < 0.001). There was no evidence of an association between the metals evaluated and WC.

Conclusions

The findings of this study generally showed that there was a significant association between demographic characteristics and exposure to these metals in children and adolescents, indicating that these people were exposed to these metals, which can harm their health. As a result, the pathways of exposure to metals must be limited.

Potentially Harmful Elements Associated with Dust of Mosques: Pollution Status, Sources, and Human Health Risks

Potentially harmful elements (PHEs) associated with dust generated from anthropogenic sources can be transported into mosques and deposited on the filters of the air-conditioners (AC); thereby, children and adults are exposed to such PHEs while visiting mosques. Data dealing with the assessment of PHEs pollution and its human health risk in mosques dust in Saudi Arabia are scarce. Therefore, this work aims to examine the levels and pollution status of PHEs in AC filter dust (ACFD) of mosques and their associated human health risk in three Saudi cities: Jubail, Jeddah, and Dammam metropolitan. A similar concentration pattern of PHEs is observed in three cities' mosques with noticeably higher concentrations than both global crustal and local background values for Zn, Cu, Pb, As, and Cd only. Except for Fe, Al, and Mn, the highest PHEs concentrations were found in Jeddah (1407 mg/kg), followed by Dammam (1239 mg/kg) and Jubail (1103 mg/kg). High PHEs' concentrations were also recorded in mosques located near workshops and suburban areas compared to urban areas. Based on the spatial pattern, enrichment factor, geo-accumulation index, pollution load index, and ecological risk values, Jubail, Jeddah, and Dammam have shown moderate pollution levels of Cd, As, Pb, and Zn. On the other hand, Cu. Zn, Cu, Cr, Pb, Ni, As, and Cd had degrees of enrichment levels that varied from significantly enriched to extremely highly enriched in the ACFD of the three cities. Heavy pollution is found in Jubail, which posed a higher potential ecological risk than in Jeddah and Dammam. Cd presents the highest ecological risk factors (ER) in the three cities. Carcinogenic and non-carcinogenic risks for children and adults follow the order: Jeddah > Dammam > Jubail, and the ingestion pathway was the main route for exposure. Carcinogenic and con-carcinogenic risks in the mosques of the various studied cities were generally within the acceptable range.

Lead content in automotive paints purchased at formal and informal outlets in Kenya

Lead (Pb) is added to automotive paints to prevent corrosion on metallic surfaces, for decorative colours, and for reflective properties to heighten visibility, and enhanced drying time, and durability. However, there are substitutes for all of these applications and Pb is highly toxic to human health and the environment. Through concerted efforts, leaded gasoline was phased out and currently, the focus is on lead-based paints. Leaded automotive paint used for spray painting activities often conducted in close proximity to human habitation raises public health concerns over possible exposure. This study was therefore undertaken to assess Pb levels in automotive paints frequently used by informal spray painters. A total of thirty-two (n = 32) cans of automotive paints were purchased in 4 sets of red, blue, green and white colours from eight formal and informal retail shops. Lead levels in the paint samples were analyzed in triplicates using Atomic Absorption Spectrophotometry. All the automotive paints from the informal retail shops had Pb levels that ranged from 220 to 2740 ppm, and exceeded the regulatory limit of 90 ppm. The blue paint from the informal store had the highest Pb levels which were 30 times of the set limit. On the contrary, the paints from the formal stores had significantly (p < 0.05) lower Pb levels that ranged from 80.7 to 580 ppm than those of the informal stores. Although only one paint sample from the former retail shop had Pb levels within the limit. In general, the elevated Pb levels in automotive paints that are used in an unregulated environment are potential sources of exposure and environmental contamination. The study urgently calls for enforcement of the regulatory limits and comprehensive Pb exposure assessments in this sector.

Lead in painted surfaces and dusts from rented urban properties (Plymouth, UK)

X-ray fluorescence (XRF) spectrometry has been used to measure lead (Pb) in painted surfaces and indoor dusts from 14 rented properties in the city of Plymouth, UK. Lead was detected in 78 out of 164 surfaces measured (and in 69 out of 150 interior surfaces) with an overall median concentration of 7100 mg kg^-1 (range from 157 to 139,000 mg kg^-1), and was detected in all but two properties that included one building constructed within the last 25 years. Selected measurements on an area basis (n = 48) returned Pb concentrations ranging from below 0.01 to 16.1 mg cm^-2 that were significantly correlated with concentrations on a mass basis but with scatter that was attributed to the degree to which leaded paint had been overpainted. As potential measures of Pb exposure, mean concentrations in samples of lint (n = 8) were <15 mg kg^-1 while mean concentrations in hoovered dusts (n = 14) were more variable; specifically, mean Pb dust concentrations ranged from ∼20 to 140 mg kg^-1 in 13 samples but was ∼4500 mg kg^-1 in a property that had recently undergone extensive renovation. Although mean concentrations of Pb in lint or dust were not related to median Pb concentrations in paint, a strong correlation between barium (Ba) and Pb in dusts suggests that paint is the main source of dust Pb. This study indicates that, in most cases, leaded paints historically applied to interior surfaces have been over-coated and pose little risk, provided that surface coatings are in good condition. However, inappropriate practices during renovation can result in significant contamination of dusts. Our findings are likely to be more broadly applicable to the urban rented sector in the UK and landlords and tenants should, therefore, be made aware of government guidance on the safe decoration or remodelling of older properties where leaded paint is pervasive.

Lead and chromium in European road paints

Lead chromate was commonly employed as a pigment in coloured road markings until restrictions led to the development of safer alternatives. In this study, the presence and concentrations of Pb and Cr have been determined in 236 road paints of various colours sampled from streets, highways, footways and carparks from eleven European countries. According to energy-dispersive X-ray fluorescence spectrometry, Pb was detected (>10 mg kg^-1) in 148 samples at concentrations up to 17.2% by weight, and above 1000 mg kg^-1 yellow was the dominant paint colour. Lead concentrations on an area basis varied from 0.02 to 8.46 mg cm^-2 and the metal was located at different depths amongst the samples, suggesting that formulations had been painted both recently and historically (and overpainted). Chromium was detected (>5 to 50 mg kg^-1) in 81 samples at concentrations between 20 and 20,000 mg kg^-1 and most often in yellow paints, and concentrations co-varied with those of Pb. These observations, and results of scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, suggested that heterogeneously dispersed PbCrO₄ was the dominant, but not the only, Pb-based pigment in the samples. Although there were significant international differences in frequency of Pb detection and median Pb concentrations, overall, and despite various, albeit complex, regulations, recent or extant road paint pigmented with Pb and Cr remains a pervasive environmental problem and a potential health risk in many European countries.

Source apportionment based on lead isotope ratios: Could domestic dog's blood lead be used to identify the level and sources of lead pollution in children?

Domestic dogs have been proved to be used as "sentinel organisms" to monitor human lead exposure. However, whether dogs' blood can be used to identify the levels and pollution source of children's lead exposure still needs evidence. To evaluate the potential use of domestic dogs' blood lead as an indicator of lead exposure levels and pollution source of children, accompanying with potential environmental media samples, lead concentrations and isotope ratios (expressed as ²⁰⁷Pb/²⁰⁶Pb, ²⁰⁸Pb/²⁰⁶Pb) in blood were investigated and compared between children and dogs, who came from a Pb-Zn smelter area, a coal fired area and a control area without industrial activity. The results showed that there were significant correlations in blood lead levels (BLLs) between children and dogs in the study areas (p < 0.01). The lead isotope ratios (LIRs) in blood of children and dogs were disparate among the three areas, however, the LIRs of dogs were quite correlated with those of children in each area (p < 0.01). With the comparison of LIRs between potential pollution sources (slag, ore, coal, paint) and blood samples, the identified lead sources based on dogs' blood were found to be coincident with those based on children's blood. Ore smelting and coal combustion were the main sources of lead exposure for the dogs and children in the smelting area, and coal combustion was the predominant source for the children and dogs living in the coal burning area and control area. The results showed that dogs' BLLs might be used to estimate children's BLLs, and blood LIRs measurements of dogs' could be used as an alternative for identifying the sources of children's lead exposure. This study further provided relevant evidence for dogs to be sentinels exposed to human lead exposure and an alternative method for source apportionment of children's lead exposure.

Blood lead levels in 2018/2019 compared to 1987/1988 in the German population-based KORA study

INTRODUCTION

Lead exposure remains of continuing concern due to its known and suspected impacts on human health and has been designated as a priority substance for investigation in human biomonitoring studies by the EU. The aims of this study were to measure blood lead levels (BLL) in a population based cohort of middle-aged individuals without major current exposures to lead, and to compare these to historical blood lead levels obtained thirty years earlier.

METHODS

The population-based KORA study from 1984 to 2001 included inhabitants of the Augsburg Region, Germany. During 2018 to 2019, a subsample of these participants (KORA-Fit) was invited for interview regarding demographic and lifestyle factors, physical examination and blood withdrawal. Blood samples were stored at -80C prior to measurement of BLL via graphite furnace atomic absorption spectroscopy (GF-AAS). Descriptive and multivariable analyses were performed.

RESULTS

BLLs were measured in 3033 eligible persons aged 54 to 73, establishing a geometric mean (GM) BLL of 24.8 μg/l in 2018/19. Of these, 555 (18%) had BLL above proposed 95th percentile reference values of the German Environment Agency. Only small differences were found in BLL stratified by sociodemographic categories, however regular smokers had higher GM BLL (26.1 μg/l) compared to never smokers (23.7 μg/l), and an increasing BLL with increased wine consumption was noted. For 556 individuals, BLLs (GM: 54.0 μg/l) reduced by 35% in men and 50% in women compared to levels in 1987/88 with only 1.4% of individuals having an unchanged or increased BLL.

DISCUSSION

KORA-Fit provided contemporary normative data for BLL in a Western European population without major current sources of lead exposure. Mean BLLs have fallen since the 1980s using historical BLL data which is likely linked to the ban of leaded gasoline. Nevertheless, BLLs in this population remain elevated at levels associated with morbidity and mortality.

Integrated review of the nexus between toxic elements in the environment and human health

Emerging pollutants in the environment due to economic development have become a global challenge for environmental and human health management. Potentially toxic elements (PTEs), a major group of pollutants, have been detected in soil, air, water and food crops. Humans are exposed to PTEs through soil ingestion, consumption of water, uptake of food crop products originating from polluted fields, breathing of dust and fumes, and direct contact of the skin with contaminated soil and water. The dose absorbed by humans, the exposure route and the duration (i.e., acute or chronic) determine the toxicity of PTEs. Poisoning by PTEs can lead to excessive damage to health as a consequence of oxidative stress produced by the formation of free radicals and, as a consequence, to various disorders. The toxicity of certain organs includes neurotoxicity, nephrotoxicity, hepatotoxicity, skin toxicity, and cardiovascular toxicity. In the treatment of PTE toxicity, synthetic chelating agents and symptomatic supportive procedures have been conventionally used. In addition, there are new insights concerning natural products which may be a powerful option to treat several adverse consequences. Health policy implications need to include monitoring air, water, soil, food products, and individuals at risk, as well as environmental manipulation of soil, water, and sewage. The overall goal of this review is to present an integrated view of human exposure, risk assessment, clinical effects, as well as therapy, including new treatment options, related to highly toxic PTEs.

Potential Health Risks of Lead Exposure from Early Life through Later Life: Implications for Public Health Education

Lead (Pb) exposure has been a serious environmental and public health problem throughout the world over the years. The major sources of lead in the past were paint and gasoline before they were phased out due to its toxicity. Meanwhile, people continue to be exposed to lead from time to time through many other sources such as water, food, soil and air. Lead exposure from these sources could have detrimental effects on human health, especially in children. UNICEF reported that approximately 800 million children have blood lead levels (BLLs) at or above 5 micrograms per deciliter (µg/dL) globally. This paper reports on the potential risks of lead exposure from early life through later life. The articles used in this study were searched from databases such as Springer, Science Direct, Hindawi, MDPI, Google Scholar, PubMed and other academic databases. The levels of lead exposure in low income and middle-income countries (LMICs) and high-income countries (HICs) were reported, with the former being more affected. The intake of certain nutrients could play an essential role in reducing (e.g., calcium and iron) or increasing (e.g., high fat foods) lead absorption in children. Elevated blood lead levels may disturb the cells' biological metabolism by replacing beneficial ions in the body such as calcium, magnesium, iron and sodium. Once these ions are replaced by lead, they can lead to brain disorders, resulting in reduced IQ, learning difficulties, reduced attention span and some behavioral problems. Exposure to lead at an early age may lead to the development of more critical problems later in life. This is because exposure to this metal can be harmful even at low exposure levels and may have a lasting and irreversible effect on humans. Precautionary measures should be put in place to prevent future exposure. These will go a long way in safeguarding the health of everyone, most especially the young ones.

Estimating the burden of diseases attributable to lead exposure in the North Africa and Middle East region, 1990-2019: a systematic analysis for the Global Burden of Disease study 2019

BACKGROUND

Lead exposure (LE) and its attributable deaths and disability-adjusted life years (DALYs) have declined in the recent decade; however, it remains one of the leading public health concerns, particularly in regions with low socio-demographic index (SDI) such as the North Africa and Middle East (NAME) region. Hence, we aimed to describe the attributable burden of the LE in this region.

METHODS

Data on deaths, DALYs, years of life lost (YLLs), and years lived with disability (YLDs) attributable to LE in the NAME region and its 21 countries from 1990 to 2019 were extracted from the Global Burden of Disease (GBD) 2019 study.

RESULTS

In 2019, the age-standardized death and DALY rates attributable to LE were 23.4 (95% uncertainty interval: 15.1 to 33.3) and 489.3 (320.5 to 669.6) per 100,000 in the region, respectively, both of which were higher among men than women. The overall age-standardized death and DALY rates showed 27.7% and 36.8% decreases, respectively, between 1990 and 2019. In this period, Bahrain, the United Arab Emirates, and Turkey had the highest decreases in the age-standardized death and DALY rates, while Afghanistan, Egypt, and Yemen had the lowest ones. Countries within high SDI quintile had lower attributable burden to LE compared with the low SDI quintile. Cardiovascular diseases and chronic kidney diseases accounted for the 414.2 (258.6 to 580.6) and 28.7 (17.7 to 41.7) LE attributable DALYs per 100,000 in 2019, respectively. The attributable YLDs was 46.4 (20.7 to 82.1) per 100,000 in 2019, which shows a 25.7% reduction (-30.8 to -22.5%) over 1990-2019.

CONCLUSIONS

The overall LE and its attributed burden by cause have decreased in the region from 1990-2019. Nevertheless, the application of cost-effective and long-term programs for decreasing LE and its consequences in NAME is needed.

Synthesis and application of starch-stablized Fe-Mn/biochar composites for the removal of lead from water and soil

Starch-stablized and Fe/Mn bimetals modified biochar derived from corn straw (SFM@CBC and SFM@CBC-350) were firstly prepared, characterized (FTIR, XRD, SEM, EDS, BET and XPS), and applied in Pb removal from water and soil. SFM@CBC and SFM@CBC-350 displayed highly effective adsorption performance of Pb²⁺ from wastewater with the maximum adsorption capacity of 170.91 mg g^-1 and 190.17 mg g^-1, respectively, which were much greater than that of FM@CBC (149.25 mg g^-1) and CBC (101.10 mg g^-1). Studies of adsorption kinetics, isotherms and thermodynamics indicated that the absorption of Pb²⁺ by SFM@CBC and SFM@CBC-350 was spontaneous and endothermic reaction, and it was controlled by monolayer chemisorption. The mechanism studies indicated that Pb²⁺ removal involved with multiple mechanism, including complexation (dominant process confirmed by XPS analysis), physical adsorption, electrostatic attraction, and cation exchange. The reusability test demonstrated that SFM@CBC and SFM@CBC-350 had very good stability and reusability. In addition, in order to further explore Pb removal performance of the modified biochar, SFM@CBC-350 was used in soil-ryegrass pot systems. Compared with the controls, the addition of SFM@CBC-350 reduced Pb content in soil and ryegrass, increased the biomass and total chlorophyll content, reduced the activity of antioxidant enzymes (CAT, SOD, MDA and POD) and ROS fluorescence intensity of ryegrass, thus alleviating Pb stress of ryegrass. Besides, the addition of SFM@CBC-350 could increase the richness and diversity of soil microorganisms, which was beneficial to the growth of ryegrass. Hence, SFM@CBC-350 has the potential of being used as a green, efficient and promising adsorbent in Pb removal from wastewater and soil.

Impact of particle sizes on health risks and source-specific health risks for heavy metals in road dust

To analyze the impact of particle sizes on sources and related health risks for heavy metals, road dust samples in Beijing were collected and sifted into five particle sizes. The positive matrix factorization (PMF), human health risk assessment model (HHRA), and Monte Carlo simulation were used in the health risk assessment and source apportionment. Results showed that mass of particles < 74 μm occupied about 50% of the total particles, while only 8.48% of the particles were > 500 μm. Mass distribution and concentrations of heavy metals in each particle size changed in temporal. Over 85.00% of carcinogenic risks (CR) were from particles <74 μm, whereas CR from particles >250 μm were ignorable. Sources for health risks in each particle size were traffic exhaust, fuel combustion, construction, and use of pesticides and fertilizers. Proportions of sources to CR differed among particle sizes. Traffic exhaust and fuel combustion contributed over 90% to CR in particles <74 μm, whereas construction contributed the highest (31.68-54.14%) among all sources in particles 74-250 μm. Furthermore, the difference between health risks based on sifted road dust and that based on unsifted road dust was quantitatively analyzed. Source-specific health risk apportionment based on unsifted road dust was not presentative to all particle sizes, and true value of health risks could be over 2.5 times of the estimated value based on unsifted road dust, emphasized the importance of sifting of road dust.

Burden of cardiovascular disease attributable to dietary lead exposure in adolescents and adults in China

Lead is a naturally occurring metal with a range of industrial applications; however, it can cause adverse health effects upon human exposure. Even if blood lead levels (BLLs) in the human body are in the acceptable range, it is independently associated with cardiovascular disease (CVD), which is the leading cause of death in China. However, the role of lead exposure in CVD outcomes has not been quantified well. A top-down approach was adopted in this study to calculate the population attribution fraction (PAF) by combining pooled BLLs in the Chinese population reported between 2001 and 2022 with the relative risk (RR) of lead-induced CVD. Subsequently, the disease burden (DB) of lead-induced CVD was estimated and expressed in disability-adjusted life years (DALYs), and the attribution analysis about various sources of lead exposure was performed. Among Chinese adolescents and adults, BLLs of 5.50 ± 2.45 μg/dL resulted in an estimated total DB (×10⁶ DALYs) of 2.21 (2.07-2.32) for CVD, including 1.18 (1.12-1.25), 0.71 (0.69-0.74), 0.23 (0.15-0.26), and 0.02 (0.02-0.02) for stroke, and ischemic, hypertensive, and rheumatic heart diseases, respectively. Dietary lead intake was a major contributor to the DB (68.1%), and lead ingested through food was responsible for 15.1 × 10⁵ DALYs of the CVD burden. Guangxi, Hunan, and Yunnan regions in China reported higher BLLs in adolescents and adults, and the DB of lead-induced CVD was higher in Hunan, Henan, and Sichuan. Lead is a risk factor for CVD that can cause significant DB. Further practical and cost-effective efforts to reduce lead exposure are urgently needed.

Lead levels of new solvent-based household paints in Zimbabwe and Botswana: A preliminary study

Background

Lead paint remains a major potential source of lead poisoning globally, but there has been no documentation on lead content in solvent paints available on the markets in Zimbabwe and Botswana.

Aim

To determine the lead content of solvent-based paints available on the market in Zimbabwe and Botswana and identify a need for a larger study to inform policy.

Methods

This pilot study was conducted in Harare, Zimbabwe, and Gaborone, Botswana. Popular brands of solvent-based household paints were bought from hardware shops in Harare (10 samples) and Gaborone (19 samples). Samples were analysed for lead content using inductively coupled plasma-atomic emission spectrometry.

Results

Seventy percent of samples from Zimbabwe were found to contain lead above 90 parts per million (ppm), the recommended regulatory limit, with ranges from less than 60 ppm to 12 000 ppm. Twenty percent of Zimbabwean samples had lead levels above 10 000 ppm. No samples from Botswana had lead concentration above the detection limit, with all levels below 100 ppm.

Lesson Learnt

Data strongly suggest very high lead content in popular brands of solvent paints in Zimbabwe, indicating a need for a larger, well-designed study for policy direction.

Toxic metals that interact with thiol groups and alteration in insect behavior

Toxic metals, such as mercury (Hg), lead (Pb), cadmium (Cd), and copper (Cu), are widespread in the biosphere, and human activities have contributed to their continuous release into the ecosystems. Metal-induced toxicity has been extensively studied in mammals; however, the effects of these metals on insects' behavior have been explored to far lesser degree. As the main mechanism of toxicity, the cationic metals, explored in this review, have high affinity for thiol-containing molecules, disrupting the function of several proteins and low-molecular-weight thiol-containing molecules. Existing literature has corroborated that Hg, Pb, Cd, and Cu can disrupt locomotor and mating behaviors, but their effects on insects' memory and learning have yet to be fully characterized. Though field studies on metal-induced toxicity in insects are limited, results from Drosophila melanogaster as an experimental model suggest that insects living in contaminated environments can have behavioral foraging and reproductive deficits, which may cause population decline. In this review, we address the interaction between metals and endogenous thiol groups, with emphasis on alterations in insect behavior.

Combined exposure of lead and high-fat diet enhanced cognitive decline via interacting with CREB-BDNF signaling in male rats

The health risks to populations induced by lead (Pb) and high-fat diets (HFD) have become a global public health problem. Pb and HFD often co-exist and are co-occurring risk factors for cognitive impairment. This study investigates effect of combined Pb and HFD on cognitive function, and explores the underlying mechanisms in terms of regulatory components of synaptic plasticity and insulin signaling pathway. We showed that the co-exposure of Pb and HFD further increased blood Pb levels, caused body weight loss and dyslipidemia. The results from Morris water maze (MWM) test and Nissl staining disclosed that Pb and HFD each contributed to cognitive deficits and neuronal damage and combined exposure enhanced this toxic injury. Pb and HFD decreased the levels of synapsin-1, GAP-43 and PSD-95 protein related to synaptic properties and SIRT1, NMDARs, phosphorylated CREB and BDNF related to synaptic plasticity regulatory, and these decreases was greater when combined exposure. Additionally, we revealed that Pb and HFD promoted IRS-1 phosphorylation and subsequently reduced downstream PI3K-Akt kinases phosphorylation in hippocampus and cortex of rats, and this process was aggravated when co-exposure. Collectively, our data suggested that combined exposure of Pb and HFD enhanced cognitive deficits, pointing to additive effects in rats than the individual stress effects related to multiple signaling pathways with CREB-BDNF signaling as the hub. This study emphasizes the need to evaluate the effects of mixed exposures on brain function in realistic environment and to better inform prevention of neurological disorders via modulating central pathway, such as CREB/BDNF signaling.

Serum lead levels and its association with overweight and obesity

BACKGROUND

Lead (Pb) exposure has been associated with cardiovascular diseases and metabolic syndrome, nevertheless its association with obesity, type 2 diabetes, and dyslipidemia markers has been little explored in Mexico. Therefore, we evaluated the association of serum Pb levels (Pb-S), with body mass index (BMI), fasting plasma glucose (FPG), total cholesterol (TC), and triglycerides (TG).

METHODS

A cross-sectional study was performed on 85 Mexican adults (57 women and 28 men). BMI was calculated, while FPG, TC, and TG were measured by the enzymatic colorimetric method. Total Pb-S levels were measured using inductively coupled plasma mass spectrometry (ICP-MS).

RESULTS

The study population was 20.3 ± 1.9 years old, showed an average of Pb-S of 0.0982 ± 0.068 μg dL^-1, and presented a frequency of overweight (OW) and obesity (OB) of 50.5% and 18.8%, respectively. Men had higher average FPG than women (Women= 83.930 ± 5.662 vs Men= 84.953 ± 6.495; p = 0.037). When we analyzed anthropometric and clinical variables, Pb-S and frequency of OW and OB were observed to increase within the categories of Pb-S tertiles (<0.001). The averages of Pb-S were 0.051 ± 0.035 µg dL^-1, 0.107 ± 0.067 µg dL^-1, and 0.151 ± 0.063 µg dL^-1 for individuals with normal weight (NW), OW, and OB, respectively. In addition, an analysis adjusted for age and sex shows Pb-S is positively associated with BMI (β = 2.76 ± 0.498, p = <0.001).

CONCLUSION

Our results evidence a significant association between Pb-S and the increase of BMI in Mexican adults and highlight the important health impact that may represent environmental Pb exposure.

Contamination by hazardous elements in low-priced children's plastic toys bought on the local markets of Karachi, Pakistan

Children's plastic toys may contain toxic metals to which infants and young children can be orally exposed and may pose acute or chronic adverse health effects. This research aims to evaluate the total metal concentrations (TMCs) of Pb, Cd, Cr, Ni, Zn, Cu, and Mn in children's plastic toys bought in the local markets of Karachi, Pakistan, and compare TMCs to different toy safety regulatory limits. A total of 44 children's plastic toys sourced in the Karachi local markets were analyzed by an atomic absorption spectrophotometer for contamination of hazardous elements. Toy samples were divided into two groups: plastic toys (DCT) and plastic toys with paints or coatings (DPCT). For plastic toys, 83% (19) of samples had TMCs that exceeded European Union (EU) toy safety regulation limits for Pb, and 65% (15) of samples that exceeded for Cd. For plastic toys with paints or coating, 43% (9) of samples had TMCs that exceeded EU migration limits for Pb and 24% (5) for Cd. More than 20 samples exceeded the United States Consumer Product Safety Commission (US CPSC), Canadian, and Bureau of Indian Standards (BIS) toy safety regulation limits. In toy samples (n = 44), very high TMCs of Pb (64%), Cd (45%), Cr (5%), and Ni (2%) were observed. Zn, Cu, and Mn TMCs existed but were below the regulation limits. The contamination levels of Pb, Cd, Cr, and Ni and smaller extent of Zn, Cu, and Mn still pose health issues in children and may cause serious problems in their health.

Functionalized Alkaline Lignin for Removal of Lead in Aqueous Solution

Lignin, the second most abundant natural polymeric globally, is considered the source of the renewable aromatic compound. It serves as an alternative feedstock for the elaboration of chemicals and polymers. However, even until now, it is still primarily used as a low-value fuel for boilers. In the current research, alkaline lignin was modified and used as an adsorbent for removing lead (Pb) in an aqueous solution. The functionalized alkaline lignin (FAL) was prepared by a Mannich reaction with formaldehyde and dimethylamine, followed by esterification of carbon disulfide. The FAL was characterized using CHN elemental analysis, X-Ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared (FT-IR) to observe the changes in composition, morphology, and chemical structure. The analysis revealed that alkaline lignin was successfully modified using amine and carbon disulfide. The adsorption study shows that the lead concentration reduced to 93.7% after 2 hours in contact with FAL. The FAL adsorption capacity could obtain 0.44 mmol/g of lead.

The Performance Comparison of Socioeconomic and Behavioural Factors as Predictors of Higher Blood Lead Levels of 0–6-Year-Old Chinese Children between 2004 and 2014

Childhood lead exposure is a commonly known risk factor affecting children’s health, and 10 governments have taken actions to reduce children’s lead exposure sources. Because lab testing for children’s blood lead levels (BLLs) was not popularized easily, socioeconomic and behavioural factors have been usually used as predictors of screening methods. Along with the overall decreasing trend of children’s BLLs, the lead-exposure-potential-predicting ability of such factors might be limited or changed over time. Our study aims to compare the predicting ability of multiple factors, including the living environment, economic disparity and personal behaviour differences between 2004 and 2014. With potential predicting factors identified, it could provide direction in identifying individual children facing high-risk lead exposure in the unit of clinics or communities of China. The study was first conducted in 12 cities in China in 2004 and then repeated in 2014 in the same 12 cities with the same method. In total, 27,972 children aged under 7 years were included in this study. With confounding factors adjusted, the child’s age, the family’s socioeconomic status and the child’s personal hygiene habit, especially biting toys, continued to be important predictors of higher blood lead levels among Chinese children. The sex of the child was no longer a predictor. Factors such as the father’s occupational contact with lead, residence near the main road and taking traditional Chinese medicine had the potential to be new predictors.

Mechanism-Enhanced Active Attapulgite-Supported Nanoscale Zero-Valent Iron for Efficient Removal of Pb2+ from Aqueous Solution

In this study, attapulgite-supported nano zero-valent iron (nZVI@ATP) was synthesized by a liquid-phase reduction method using active attapulgite (ATP) as raw material, and used for Pb2+ remediation in aqueous solution. To understand the mechanism of Pb2+ removal, various techniques were used to characterize nZVI@ATP. The results showed that spherical nZVI particles were uniformly dispersed on the surface of ATP, and the agglomeration of nZVI particles was significantly weakened. The adsorption performance of nZVI@ATP for Pb2+ was greatly improved compared with that of ATP ore, in which the Fe/ATP mass ratio of 1:2 was the best loading ratio. Under the conditions of a temperature of 25 °C and a pH of 5.00, the initial concentration of Pb2+ was 700 mg/L, and the Pb2+ removal rate of nZVI@ATP was 84.47%. The adsorption of nZVI@ATP to Pb2+ was mainly a spontaneous endothermic reaction of heterogeneous surfaces, and the adsorption rate of nZVI@ATP to Pb2+ was proportional to pH in the range of 2–5.5. The presence of Na+, Mg2+, and Ca2+ can inhibit the removal of Pb2+, and Ca2+ has the strongest inhibition effect on the removal of Pb2+. The removal mechanism of Pb2+ by nZVI@ATP obtained from SEM-EDS, BET, XRD, FTIR and XPS included reduction, precipitation, and the formation of complexes.

Association between lead source exposure and blood lead levels in some lead manufacturing countries: A systematic review and meta-analysis

Lead is one of the 10 most toxic chemicals of greatest concern for its effects on public health. Predominantly, in undeveloped countries, high blood lead levels (BLLs) persist in the population. To develop intervention strategies that may reduce lead exposure in populations, it is a priority to know the sources of lead pollution. The objective of this critical review and meta-analysis is to assess whether there is an association between different sources of lead exposure and the mean difference in blood lead levels in people exposed. To identify the major lead source exposure, a statistical analysis was performed on selection studies. This investigation reveals the limited information available on the sources of lead in Mexico and other lead producer countries, such as Croatia, Ecuador, Brazil, South Korea, India, Nigeria, Turkey, and China. Meta-analysis could be performed only in battery, smelting mining, and glazed ceramic workers. Battery manufacturing workers have the highest mean difference level of lead in their blood worldwide. Mexico has the second highest mean difference BLL in battery workers in the world. An interesting difference between the mean difference in BLL in mining workers from uncontrolled industry (-39.38) and controlled industry (-5.68) was found. This difference highlighted the success of applying strict control of lead sources and community education to reduce BLL and its potential harmful effects on human health and the environment. Children living near mining sites have the highest mean difference BLL (-11.1). This analysis may aid in assessing the source of lead exposure associated with a range of BLLs in people. Furthermore, this review highlights several social and cultural patterns associated with lead exposure and lead levels in control populations. These results could help to develop international lead regulations and appropriate public health guidelines to protect people around the world.

Association of As, Pb, Cr, and Zn urinary heavy metals levels with predictive indicators of cardiovascular disease and obesity in children and adolescents

BACKGROUND

Although the basic causes of obesity and cardiovascular illness have been extensively researched, little is known about the influence of environmental variables such as heavy metals on obesity development and cardiovascular disease in children and adolescents. The assumption that arsenic (As), lead (Pb), chromium (Cr), and zinc (Zn) exposure impact obesity and predictors of cardiovascular disease was explored in this study.

METHOD

A questionnaire was used to gather demographic information as well as certain determinants of exposure to As, Pb, Cr, and Zn from 106 children and adolescents aged 6 to 18. Physical tests (height, weight, waist circumference (WC), BMI, BMI Z-score, Systolic blood pressure (SBP), Diastolic blood pressure (DBP)), blood samples for clinical trials (Fasting Blood Sugar (FBS), Total Cholesterol (TC), Triglyceride (TG), Low-Density Lipoprotein (LDL), High-Density Lipoprotein (HDL) (, and urine samples for urinary creatinine measurement and measures of As, Pb, Cr, and Zn in urine were obtained using the Inductively coupled plasma mass spectrometry (ICP/MS).

RESULTS

The average age of the participants in the research was 11.42 ± 3.68. The majority of the participants in the research were boys (56 people). As, Pb, and Zn mean concentrations (μg/L) were greater in obese adults (42.60 ± 22.59, 20.63 ± 14.64, 326 ± 164.82), respectively. After adjusting for possible confounding factors, the data revealed that adolescents aged 12-18 years had higher levels of As and Pb (8.69 and 5.02 μg/L) than children aged 6 to 11. As and Zn metals had significant association with FBS and lipid profile (TC, TG, LDL, HDL), lead had significant correlations with lipid profile, while Cr had significant correlations with WC, SBP, FBS, LDL, TC.

CONCLUSION

Childhood and adolescent exposure to As, Pb, Cr, and Zn can impact obesity and cardiovascular disease markers. The current research was a cross-sectional study, which necessitates group studies and case studies to evaluate causal relationships.

Mapping of Female Breast Cancer Incidence and Mortality Rates to Socioeconomic Factors Cohort: Path Diagram Analysis

OBJECTIVES

Breast cancer is the leading cause of death in women around the world. Its occurrence and development have been linked to genetic factors, living habits, health conditions, and socioeconomic factors. Comparisons of incidence and mortality rates of female breast cancer are useful approaches to define cancer-related socioeconomic disparities.

METHODS

This was a retrospective observational cohort study on breast cancer of women in several developed countries over 30 years. Effects of socioeconomic factors were analyzed using a path diagram method.

RESULTS

We found a positive, significant association of public wealth on incidence and mortality of breast cancer, and the path coefficients in the structural equations are -0.51 and -0.39, respectively. The unemployment rate (UR) is critical and the path coefficients are all 0.2. The path coefficients of individual economic wealth to the rates of breast cancer are 0.18 and 0.27, respectively.

CONCLUSION

The influence of social pressure on the incidence and mortality of breast cancer was not typical monotonous. The survival rate of breast cancer determined by the ratio of mortality rate to incidence rate showed a similar pattern with socioeconomic factors.

A Literature Review of Unintentional Intoxications of Nonhuman Primates

Simple Summary

This report is an overview of the published veterinary literature on unintentional poisonings in wild and captive nonhuman primates (NHP). Selected intoxications will be described with emphasis on the clinical signs, laboratory, and main postmortem findings as well as the available treatment options. Mostly, NHP died suddenly and unexpectedly without showing any preceding clinical signs. The (presumptive) diagnosis of a poisoning was mostly made postmortem by laboratory testing of post-mortem fluid, tissue samples, and stomach contents. From these reports, we concluded that the toxic threats to wild NHP are different to those of captive NHP because of the environment in which they live. We also concluded that a poisoning or an intoxication should be part of a differential diagnosis when a NHP presents with clinical signs that cannot be linked to a known disorder or dies suddenly with no preceding clinical signs.

Abstract

Reports of unintentional intoxications in nonhuman primates (NHP) are few and an up-to-date review of such intoxications in NHP is lacking. We reviewed the published veterinary literature on unintentional intoxications in wild and captive NHP in order to provide a useful resource on known toxic agents of NHP for veterinarians, caregivers, and researchers who work with NHP. To these ends, we first conducted a literature search for books, book chapters, peer-reviewed publications, conference proceedings, and newsletters in academic literature databases such as Google Scholar, PubMed, BioOne Complete, and Web of Science using the words and word combinations such as heavy metals, pesticides, poisonings, and nonhuman primates. We then evaluated the search results for those reports that we considered as clinically relevant and then classified them according to the toxic agent. We identified lead, zinc, phytotoxins, pesticides, botulinum toxin, polychlorinated biphenyls, and snake and spider venoms as the main toxic agents in wild and captive NHP. We concluded that the toxic threats to wild NHP are different to those of captive NHP because of the environment in which they live. We recommend that an intoxication should be part of a differential diagnosis when a NHP presents with clinical signs that cannot be linked to a known disorder or dies suddenly with no preceding clinical signs. In cases of the former, laboratory testing for known toxins and pollutants should be conducted. In cases of the latter, a thorough postmortem examination, together with extensive laboratory testing, for known toxins and environmental pollutants in all tissues and organs should be performed.