Lead Contaminants Research Articles

Mechanobiological mechanisms in the remediation of soil lead pollution using two-dimensional carbon materials and Morchella: A molecular-level study

Graphene-based 2D carbon composites and Morchella mushrooms are used in the paper to study the mechanobiological mechanisms of soil lead remediation. Soil is contaminated with lead, which threatens ecosystems and human health, making it even more important to find remedies. To fully comprehend these processes, present-day materials, and organic compounds are needed to improve soil nutrition and eradicate lead. To deal with the challenge of finding effective means of lead removal; limitations associated with traditional soil pollution remediation methods; and merging biology and material sciences. Multifunctional graphene wettability-patterned nanocoated membranes (MGW-PNM) is a novel technique developed to overcome these challenges. Such processes result in membranes with different wettability patterns that take advantage of the properties of graphene. This facilitates better interaction between the membrane itself and the surrounding soil as well as lead contaminants by modifying its hydrophobicity or hydrophilicity characteristics. For effective removal of lead, extensive simulation studies were done using MGW-PNM. In line with this, it can be inferred that MGW-PNM also remediates highly capable soils at high-efficiency levels. This was established when comparing modern techniques to past ones where considerable improvements were made on how much lead is extracted from them. The study suggests new ways of addressing environmental contamination resulting from microbial activities in soils by combining advanced materials with biological substances such as Morchella spp. For this purpose, it investigates various molecular interactions occurring among carbonaceous species called Morchella microbes and environmental pollutants like those including Pb.

Recovery of ecosystems pollution by contaminants of potential concern using phytoremediation techniques.

Phytoremediation is a technology that uses plants to break down, remove, and immobilize contaminants in surface water, shallow groundwater, and sediment to achieve cost savings compared with conventional treatments. This study describes a marshy land on an explosives manufacturing site in India that consistently reported elevated concentrations of nitrates, nitrites, ammonia, perchlorate, and lead (contaminants of potential concern-CoPC). The study also illustrates the potential for addressing the human health and environmental risks associated with the explosives manufacturing industrsy in India using innovative, sustainable, and carbon-neutral techniques. This work focuses on reconstructed marshy lands, desedimentation, microwatershed management, and phytoremediation using Phragmites and Vetiveria species (also known as vetiver) to reduce contaminants in surface water and groundwater, improve stormwater management and carbon capture, and increase natural capital like biodiversity. The results obtained during the trial indicate that the selected indigenous species are effective and can be used to remediate sediment and shallow groundwater for many CoPC in tropical climates. Integr Environ Assess Manag 2024;20:1987-2002. © 2024 SETAC.

Removal of lead ions from aqueous solution by modified nanocellulose.

Heavy metals significantly impact the environment due to their non-biodegradable, toxic, and carcinogenic behaviors. Lead contaminants impose severe health impacts on humans and the water environment. Therefore, eco-friendly and efficient lead ion removal practices such as nanotechnology are an urgent requirement for the abatement of lead pollution. In the present study, nanocellulose was synthesized from the cotton straw residue using chemical methods and modified with titanium dioxide to form a nanocomposite. The nanocomposite synthesized was characterized by using FTIR, XRD, FESEM, and BET. FTIR results noticed peaks at 1648.43 and 1443.57cm-1 for cellulose and Ti-O-Ti bonding at 505.02cm-1. The nanocomposite was noticed to be disordered and irregular in shape. The nanocomposite has particle sizes of 83nm. The nanocomposite crystalline particle had 65% anatase and 32% rutile phases observed from the XRD result. BET results show that the surface area of nanocellulose increases after surface modification from 25.692 to 42.510 m2/g. The adsorption capacity of the nanocomposite was 0.552mg/g was noticed. The Elovich kinetic and Baudu isotherms are the best-fitted models for lead ion adsorption. Thermodynamic parameters resulted in Gibbs free energy decreasing with temperature. This study revealed that modified cellulosic adsorbents efficiently absorbed lead ions derived from cotton straws.

A Direct Chemical Approach to Mitigate Environment Lead Contamination in Perovskite Solar Cells

Current guidelines indicate that the lead levels in perovskite solar cells are sufficiently low, putting them on par with the safety of other lead-containing electronics. Yet, there remains ambiguity regarding the exact environmental impact of lead derived from perovskite. When this lead enters the soil, it has the potential to permeate plants and, subsequently, our food supply, at a rate that is a staggering ten times more than other lead contaminants from human-induced activities. Given this, it becomes vital to ensure that lead does not pollute our environment as we further adopt these technologies. In this study, we propose a novel method using polymer net bones to anchor the lead, which effectively reduces the risk of lead leaching due to rainfall. Perovskite Solar Cells (PSCs) integrated with this polymer net bone show improved operational efficiency and hold significant promise in curtailing lead leakage, reinforcing the ecological integrity of perovskite solutions. When enhanced with Polyvinyl Alcohol (PVA), these PSCs register a notable increase in Power Conversion Efficiency (PCE), scoring 24.7% as opposed to the 22.3% in PSCs devoid of PVA. Additionally, PVA-augmented PSCs outperform in stability when compared to their traditional counterparts.

Selective Adsorption Behavior of Sulfuric Acid Oxidized and Doped Conjugated Microporous Poly(aniline)s toward Lead Ions in an Aqueous Environment.

The coexistence of lead, zinc, and copper ions in wastewater constitutes an environmental challenge of pressing concern. This research delves into the preparation of innovative oxidation-doped conjugated microporous poly(aniline) frameworks, exploring their prospective efficacy in regulating lead ion adsorption from aqueous solutions. H2SO4-CMPTA demonstrates the capability to reach adsorption equilibrium within 15 min at a lead concentration of 50 ppm. Even at a lead concentration of 20 ppm, it still efficaciously attenuates these levels to sub-10 ppb, a value surpassing extant standard. H2SO4-CMPTA retains over 78.8% adsorption efficiency after six cycles. Analytical characterization coupled with computational calculations suggests that sulfate-coordinated nitrogen cationic structure plays a crucial role in adsorption. A deeper investigation reveals the cardinal role of electrostatic attraction and exclusive chelation adsorption underpinning the efficient capture of lead ions by doped sulfate ions. Intriguingly, in a mixed heavy metal solution containing lead, zinc, and copper ions, H2SO4-CMPTA exhibits an initial predilection toward zinc ions, yet an eventual ion-exchange adsorption gravitating toward lead ions was discerned, governed by the latter's superior binding energy. Our study elucidates a promising material as an efficacious tool for the remediation of aquatic environments tainted with lead contaminants.

Production of 203Pb from enriched 205Tl using deuteron beams

Lead-203 is a SPECT emitter that can be used in theranostic applications as an imaging counterpart of lead-212 which is intended to be used for alpha therapy as lead-212/bismuth-212 in-vivo generator. In our study, we explore the production of lead-203 using enriched thallium-205 target irradiated by a deuteron beam. Excitation functions of deuteron induced reactions leading to the formation of 204m,203m2+m1+g,202m,201m+gPb, 202Tl and 203m+gHg isotopes were determined experimentally in the energy range from 21 MeV to 34 MeV. Cross sections were measured using the stacked foils technique and a set of two monitor foils, natNi and natTi for beam intensity evaluation. The experimental excitation functions of the investigated reactions were compared with the published data and also with the TENDL-2021 nuclear database. From our experimental data, we calculated lead-203 thick target yield in the energy range between 30 MeV and 32.5 MeV to be 56.7 MBq/μAh ±6.1 MBq/μAh. This value is compatible with large batch production showing that deuteron beams can be used for a routine production process. However, special attention must be paid to 203Hg and other lead contaminants.

Assessing the Health Risks of Heavy Metal Contamination in Water Sources Utilized for Palm Oil Production in Selected Local Industries in Ondo State, Nigeria

This study investigates into the adverse impacts of heavy metal concentration on human health, particularly when present in water used in palm oil production in selected industries in Ondo State, Nigeria. Through wet-digestive analysis, the levels of heavy metals including Copper (Cu), Lead (Pb), Manganese (Mn), Zinc (Zn), and Cadmium (Cd) were assessed in both water samples and palm oil products. The results revealed concentrations of heavy metals in water samples and control ranging from Copper (0.167 – 0.297 and 0.143 mg/L), Lead (0.047 – 0.100 mg/L), Manganese (0.250 – 0.327 mg/L), and Zinc (0.0417 – 0.547 mg/L), while palm oil concentrations ranged from Cu (0.327 - 0.100 mg/L), Ni (0.045 - 0.010 mg/L), Pb (0.207 – 0.100 mg/L), Mn (0.390 - 0.183 mg/L), and Zn (0.697 – 0.453 mg/L). Comparison with World Health Organization (WHO) standards indicated that Pb concentrations in water exceeded permissible limits, suggesting potential contamination in palm oil samples. Additionally, a significant positive correlation (p<0.05) was observed between Pb levels in water and palm oil samples, indicating the transfer of lead contaminants into the palm oil during production. These findings underscore the importance of monitoring and regulating heavy metal concentrations in water sources used in palm oil production to safeguard public health.

Electrochemical Method for Detection and Quantification of Lead Particulate in Tap Water

Quantification of lead particulates requires laborious sample acidification and/or digestion in acidic environment, therefore lead quantification is limited to laboratories with trained personnel and expensive instrumentation. These technologies are not easily accessible to the public, and the large number of portable methods available to public today are characterized by their qualitative nature, and requirement of additional reagents. Unlike labor intense expensive instruments, electrochemical methods are inexpensive, fast and portable but they are blind to non-electroactive lead species or particulate forms of lead. They are limited to the detection of ionic or electroactive analytes. This talk will report an electrochemical method for the detection and quantification of lead contaminant in drinking waters that results from particulate forms of lead, mostly present as scales. We will present the fundamentals of membrane electrolysis for reagent-free sample preparation and detection of Pb2+. Also, we will present the characterization of real particulates/scales extracted from lead service lines from the Cincinnati area. We think this method will contribute to the development of on-site, quantitative methods of lead detection, and can assist to the research and understanding of drinking water contamination. Perhaps it could help to determine what triggers lead intermittent release to residential tap water. This work has the potential to address the lack of that instrumentation because it employs a robust technology based on anionic exchange membrane and controlled electrolysis for in-situ generation of nitric acid, that eliminates the need of external reagent or sample treatments. For its trace detection, it employs a well stablished Anodic Striping Voltammetry method.

Phytoextraction and Stabilization of Lead in Contaminated Soils using Plants

Lead is a toxic heavy metal contaminant that poses a serious threat to human health. It is present everywhere in the environment including agricultural, industrial and residential areas. To remediate lead from the contaminated soil, phytoremediation approaches are used. Phytoextraction and Phytostabilization are methods of phytoremediation which has been successfully used to remediate lead contaminant from the soil. Phytoextraction involves the use of hyperaccumulators; to accumulate lead contaminant within the shoots by using the uptake mechanism. Whereas, Phytostabilization involves the stabilization or maintenance of lead in the rhizosphere of the soil to reduce its harmful impact on the environment. Lead phytoextraction could be enhanced by adding chelating agents, such as EDTA, to increase the bioavailability of lead contaminant in the plants. Lead phytostabilization is an effective method to remediate lead contaminant. This method tolerates lead exposure and prevents it in or around the root zone which can restrict the movement of lead into other plants, avoiding resuspended dust and mitigating lead exposure. These approaches are cost effective, simple; ecofriendly and do not require a huge amount of labour.

Lead and Zinc Groundwater Contaminant Transport Modelling Using MT3DMS in Xaysomboun Province, Lao PDR

Contaminant transport modelling is commonly applied in the Groundwater Modelling System (GMS). Modular Three-Dimensional Multispecies Transport (MT3DMS) package is one of other packages, developed by the U.S. Geological Survey, this research presents the employing of the M3TDMS package as excellent tools to establish the 3D conceptual model of contaminant transport modeling, simulate and predict the multispecies of Lead and zinc substances which transport in the groundwater, there are 15 boreholes that were observed and monitored, the results of the contaminant transport modeling was found the Lead(Pb) contaminant transport with initial concentrations of 3.96 mg/l at borehole MB48 as point source, the concentration reduced to 0.1 mg/l, after 3,650 days simulation. The initial zinc (Zn) concentration of 0.886 mg/l at borehole CV04 decreases to 0.023 mg/l after 3,650 days simulation.

The distribution of metal and petroleum-derived contaminants within sediments around oil and gas infrastructure in the Gippsland Basin, Australia

As oil and gas infrastructure comes to the end of its working life, a decommissioning decision must be made: should the infrastructure be abandoned in situ, repurposed, partially removed, or fully removed? Environmental contaminants around oil and gas infrastructure could influence these decisions because contaminants in sediments could degrade the value of the infrastructure as habitat, enter the seafood supply if the area is re-opened for commercial and/or recreational fishing, or be made biologically available as sediment is resuspended when the structures are moved. An initial risk hypothesis, however, may postulate that these concerns are only relevant if contaminant concentrations are above screening values that predict the possibility of environmental harm or contaminant bioaccumulation. To determine whether a substantive contaminants-based risk assessment is needed for infrastructure in the Gippsland Basin (South-eastern Australia), we measured the concentration of metals and polycyclic aromatic hydrocarbons (PAHs) in benthic sediments collected around eight platforms earmarked for decommissioning. The measurements were compared to preset screening values and to background contaminant concentrations in reference sites. Lead (Pb), zinc (Zn), PAHs and other contaminants were occasionally measured at concentrations that exceeded reference values, most often within 150 m of the platforms. The exceedance of a few screening values by contaminants at some platforms indicates that these platforms require further analysis to determine the contaminant risks associated with any decommissioning option.

Optimization and prediction of lead removal from aqueous solution using FO–MD hybrid process: Statistical and artificial intelligence analysis

Heavy metals (HMs) has become one of the most serious pollutants that are harmful to the environment and ecology. This paper focused on the removal of lead contaminant from wastewater by forward osmosis–membrane distillation (FO–MD) hybrid process using seawater as draw solution. Modeling, optimization, and prediction of FO performance are developed using complementary approach based on response surface methodology (RSM) and an artificial neural network (ANN). FO process optimization using RSM revealed that under initial lead concentration of 60 mg/L, feed velocity of 11.57 cm/s and draw velocity of 7.66 cm/s, FO process achieved highest water flux of 6.75 LMH, lowest reverse salt flux of 2.78 gMH and highest lead removal efficiency of 87.07%. Fitness of all models was evaluated based on determination coefficient (R2) and mean square error (MSE). Results showed highest R2 value up to 0.9906 and lowest RMSE value up to 0.0102. ANN modeling generates the highest prediction accuracy for water flux and reverse salt flux, while RSM produces the highest prediction accuracy for lead removal efficiency. Subsequently, FO optimal conditions are applied on FO–MD hybrid process using seawater as draw solution and evaluate their performance to simultaneously remove lead contaminant and desalination of seawater. Results displays that FO–MD process shows a highly efficient solution to produce fresh water with almost free heavy metals and very low conductivity.

Poly(ethylene glycol) Diacrylate Hydrogel with Silver Nanoclusters for Water Pb(II) Ions Filtering

Poly(ethylene glycol) diacrylate (PEGDA) hydrogels modified with luminescent silver nanoclusters (AgNCs) are synthesized by a photo-crosslinking process. The hybrid material thus obtained is employed to filter Pb(II) polluted water. Under the best conditions, the nanocomposite is able to remove up to 80-90% of lead contaminant, depending on the filter composition. The experimental results indicate that the adsorption process of Pb(II) onto the modified filter can be well modeled using the Freundlich isotherm, thus revealing that the chemisorption is the driving process of Pb(II) adsorption. In addition, the parameter n in the Freundlich model suggests that the adsorption process of Pb(II) ions in the modified hydrogel is favored. Based on the obtained remarkable contaminant uptake capacity and the overall low cost, this hybrid system appears to be a promising sorbent material for the removal of Pb(II) ions from aqueous media.

Assessment of Microbial Air Quality of Nashik City with Particular Reference to Mucorales Fungi, and in Vitro Evaluation of Two Triazole Antifungal Drugs against the Prevalent Mucor Species

Air pollution particularly that of particulate matter (PM 2.5, PM 2.10), carbon monoxide, ozone, nitrogen dioxide, sulfur dioxide, ammonia, lead, and air microbial contaminants, has serious consequences on human health. Air pollution in metros and cities around the world is measured for the above parameters except for the microbial air contaminants. However, microbial air contaminants are important sources of microbial infection in humans and particularly airborne fungi are known to cause diseases like Aspergillosis and Mucormycosis in immunocompromised patients which are about 160 million in the world.In the year 2021, Mucormycosis disease was reported as a post-covid infection in several states of India as a fatal disease caused by a black fungus (Mucor) prevalent in the atmospheric air. In the present study, we assessed the microbial air quality (colony forming unit of microbes/m3 of air) of Nashik city air, in India, for its microbial contaminant, particularly Mucor sp., and further the prevalent Mucor sp. was evaluated for its reaction to two triazole antifungal drugs viz. Itraconazole and Fluconazole available in medical stores.The air quality index of 90 CFU/tidal volume for Mucor species was regarded as safe, based on the studies. Both the triazole drugs at their active ingredient concentration (1000 µg/mL) were unable to check the growth of Mucor fungi. The paper discussed in detail the methods for enumeration of microbial contaminant/m3 of air and in tidal volume.

Theorizing on neo public assistance: How do race and class impact resource uptake and behavior following disaster?

The consequences of environmental disasters and other ecologic and communal crises are frequently worst in racially/ethnically minoritized and low-income populations relative to other groups. This disproportionality may create or deepen patterns of governmental distrust and stoke health promotion disengagement in these groups. To date, there has been limited contextualization of how historically disenfranchised populations utilize government-administered or facilitated resources following such disasters. Focusing on the water crisis in Flint, Michigan, we examine and theorize on the usage of neo public assistance, free risk reduction resources that are provided to disaster survivors as a liminal means of redressing ills created and/or insufficiently mitigated by the state. We surveyed 331 Flint residents, evaluating their usage of four neo public assistance resources following the FWC, finding low to moderate uptake: 131 residents (39.6%) indicated that they obtained blood lead level (BLL) screenings, 216 (65.3%) had their tap water tested for lead (Pb) and other contaminants, 137 (41.4%) had their home water infrastructure replaced, and 293 (88.5%) had acquired bottled water at community distribution sites. Unemployment, receiving public benefits, and lacking reliable transportation and stable housing were associated with lower uptake of some resources. Compared to White and “Other” race individuals, Black residents were generally more likely to acquire/utilize these resources, suggesting heightened concerns and health promotion proclivities even in the face of observed macro and individual-level challenges. Potential reasons and implications are discussed.

Lead and Cadmium Ions Mitigation in Soil using Calcium Carbide Waste-Carbonised Lophira Alata Sawdust Composite (CCW-CLAS) as Immobilizing Agent

Soil contamination with heavy metals is a global environmental matter of interest due to its thinkable dangers to humans, environmental health and ecosystem preceding shortfalls in agricultural produce and dangerous health outcomes as they penetrate the food chain. The aim of this study was to mitigate lead and cadmium ions contaminant in soil using calcium carbide waste-carbonized lophira alata sawdust composite (CCW-CLAS). Contaminated soil samples were collected from Evbareke spare parts market, Benin City, Edo state Nigeria, using a grid sampling method at the depth of 0-20cm with the aid of soil auger. 50% W/W of the powdered calcium carbide waste and lophira alata sawdust was placed in a ceramic crucible and put into muffle furnace and heated at 350oC for 3 hours. The X-ray diffraction analysis for the calcium carbide waste-carbonized lophira alata sawdust composite (CCW-CLAS) revealed that it was made up of predominantly calcite fraction (55.0%), portlandite (25.0%), coesite (7.3%), muscovite (6.7%), dolomite (4.0%) and lime (2.1%) this was supported by FTIR analysis. SEM analysis revealed that calcium carbide waste-carbonized lophira alata sawdust composite (CCW-CLAS) possess a rough surface with pore of varied size and irregular shape. The contaminated soil from the Evbareke spare parts market was heavily polluted with petroleum hydrocarbons, and the soil was highly saline with low C.E.C. The soil texture was loamy-sand. As the amount of CCW-CLAS increased in the soil, the amount of cadmium and lead ions that was releasable in the soil reduced, indicating that CCW-CLAS was effective in immobilizing cadmium and lead ions. The optimum amount of the amender in the contaminated soil to immobilize lead ion was 4% w/w and cadmium ion was 2%.

DNAzyme-based biosensor for sub ppb lead ions detection using porous silicon Fabry-Pérot interferometer

Herein, we present an optical sensing approach based on nanostructured porous silicon (PSi) Fabry-Pérot interferometers for real-time monitoring of lead (Pb2+) contaminants using DNAzyme, a synthetic DNA sequence with a functional catalytic region. The latter cleaved the complementary DNA/RNA substrate strand in the presence of Pb2+, which resulted in a decrease in the average refractive index of the total porous void. The interfacial optical contrast was enhanced by coupling silica nanoparticles to the complementary strand, thus improving the interferometer’s inherent performance. The catalytic activity of the DNAzyme-modified platform was monitored in real-time using reflective interferometric Fourier transform spectroscopy. The optimized conditions offered means for accurate, rapid (~20 min) and precise detection of Pb2+ in the range of 0.1–25 ppb with a detection limit of 0.49 ppb (2.4 nM). Sufficient selectivity and specificity were attained against other commonly known metallic pollutants in water sources. Finally, the practical applicability of the biosensor’s performance was demonstrated using real samples, such as ground, irrigation, tap water and even plasma, while depicting satisfactory recovery values of 94–103% in compliance with the ICP-MS approach. Overall, the developed sensing platform coupled to optical signal amplification can be easily redesigned for targeting other metal pollutants posing risks to water sources and the environment.

Deep eutectic solvents for the removal of lead contaminants in mangrove soil

The remediation of heavy metal contaminated mangrove soil with proper washing agents is critical for reducing the harmfulness of heavy metal contaminated soil to the environment. This work is aimed to investigate the potential of natural-based deep eutectic solvents as soil washing agents. Choline chloride (ChCl) and two organic acids, lactic acid and levulinic acid, are used as degradable and natural washing agents to remove Pb in the soil. Results verified that ChCl: Lactic Acid (1:2) [ChCl-LacA] and ChCl: Levulinic Acid (1:2) [ChCl-LevA] were found to be suitable for the removal of Pb from the contaminated soils, which significantly lowers the total Pb concentration in the soil. The high distribution ratio from the Conductor-like Screening Model for Real Solvents (COSMO-RS) screening gave an early indication that natural acid DESs are effective soil washing agents. The effect of washing agent concentration, soil to liquid ratio, contact time, and the interaction between acid DESs and metal ions was evaluated. ChCl-LacA and ChCl-LevA remove lead to 97% and 99%, respectively, under optimum conditions. ICP-MS, XRD, and FTIR spectroscopy analysis clarified the interaction between DES and metal ions. As a washing agent, green and natural DESs provide an environmentally sustainable alternative. Employing soil washing to remove heavy metals is a simple, rapid, and cheap remediation technology that could potentially be used in mitigating soil pollution.

Mild Hydrothermal Synthesis of 11Å-TA from Alumina Extracted Coal Fly Ash and Its Application in Water Adsorption of Heavy Metal Ions (Cu(II) and Pb(II))

Non-biodegradable copper (Cu) and lead (Pb) contaminants in water are highly toxic and have series adverse effects. Therefore, it is very important to extract heavy metals from wastewater before it is discharged into the environment. Adsorption is a cost-effective alternative method for wastewater treatment. Choosing a low-cost adsorbent can help reduce the cost of adsorption. In this study, conversion of reside after extracting aluminum (REA) produced by sub-molten salt method transform high-alumina coal fly ash (CFA) into 11Å-tobermorite to adsorb Cu(II) and Pb(II) from aqueous solutions at room temperature. The synthesis of the adsorbent was confirmed using scanning electron microscope (SEM), X-ray diffractometer (XRD) and Brunauer–Emmett–Teller (BET) method surface analysis. To study the adsorption characteristics, factors such as initial Cu(II) and Pb(II) concentration, pH, contact time, adsorption characteristics and temperature were investigated in batch mode. The maximum adsorption capacity of Cu(II) and Pb(II) was 177.1 mg·g−1 and 176.2 mg·g−1, respectively. The Langmuir adsorption model was employed to better describe the isothermal adsorption behavior and confirm the monolayer adsorption phenomenon. The pseudo-second-order kinetic model was used to highlight Cu(II) and Pb(II) adsorption kinetics. Thermodynamic analysis indicated the removal Cu(II) and Pb(II) by TA-adsorbent was a nonspontaneous and exothermic reaction. The obtained results are of great significance to the conversion of industrial waste to low-cost adsorbent for Cu(II) and Pb(II) removal from water.

Lead (Chemicals and Contaminants).

Food Safety Commission of Japan (FSCJ) conducted risk assessment of lead (hereinafter referred to as Pb) as a Self-Tasking assessment. Risk assessments of Pb were initially requested from the Ministry of Health, Labour and Welfare in relation to revision of the standards for apparatus/container and packaging (ACP) and to revision of the standards for beverages. Considering the diverse modes and routes of human exposure to Pb, FSCJ judged that a comprehensive risk assessment of Pb is appropriate instead of specific risk assessment relating to ACP or beverages. To estimate the actual Pb exposure of the general population in Japan, the present Self-Tasking assessment working group started to inspect available data of blood Pb levels among children (12 years old boys and girls, n = 289, surveyed for 2015-2018) and among adults (pregnant women, n = 96,696, surveyed for 2011-2014)1). FSCJ concluded that average blood level of Pb of current Japan is about 1 µg/dL or less based on the data available at present. Comprehensive evaluation of the findings from the previous epidemiological studies suggested that even blood Pb at the level of 1-2 µg/dL potentially affected children’s neuro-behavioral development or adult renal function. FSCJ, however, concluded that figuring out of a blood Pb level without adverse effects was difficult from the data of epidemiological studies. Pb level in current Japan as about 1 µg/dL or less. This value is close to the level potentially to have some effects, 1-2 µg/dL as suggested by epidemiological studies. Continuous implementation of measures to reduce Pb exposure is thus required. A close watch on the trend of blood Pb level by human biomonitoring is also necessary for verification of the efficacy of the measures to reduce Pb exposure.