Lead Dust Research Articles

Preparation of metallic lead from lead sulfide by bagged cathode solid-phase electroreduction in a low-temperature and weakly alkaline solution

Developing a method to recovering metallic lead from lead sulfide at lower temperatures without emitting lead dust and SOx gas holds significant importance in terms of environmental sustainability and economy efficiency. In this study, we employ a bagged cathode to directly produce metallic lead from lead sulfide in a low-cost weakly alkaline electrolyte (200 g/L Na2SO4 + 0.1 mol/L NaOH) at a temperature as low as 40 °C. The use of bagged cathode effectively immobilizes reactants and reduces cathodic polarization, thereby enabling the electro-reduction of lead sulfide under mild conditions. During the electroreduction process, the granular lead sulfide powders gradually undergo transformation into rod- or sheet-like metallic lead, achieving lead recovery ratio and desulfurization rate reaching 96.4 % and 97.9 %, respectively. Cyclic voltammetry analysis confirms that the oxidation reaction of S2− released from cathode is irreversible, thereby not interfering the cathodic electroreduction of lead sulfide. This bagged cathode direct electroreduction method utilizing a low-temperature, weakly alkaline aqueous solution exhibits the potential for application to other sulfides or oxides.

Standards for levels of lead in soil and dust around the world

Abstract Lead poisoning is a serious environmental health problem in every country in the world. Exposure to lead results in neurocognitive and behavioral changes, has adverse effects on the immune system, causes anemia, hypertension and perturbs other organ systems. The effects of lead poisoning are most critical for children because their bodies are growing and developing, and particularly because agents that reduce cognitive function and attention span as well as promote disruptive behavior will have life-long consequences. Lead exposure, especially to children, is a major health disparity issue. If the next generation starts with reduced cognitive ability, there will be significant barriers for development of skills and country-wide development. While there are many sources of exposure to lead, the commonest source is lead in soil and dust. Since lead is an element, it does not go away and past releases of lead into the environment remain as soil and dust contamination. This is an especially important route of exposure to children because children regularly play in soil and are exposed via hand-to-mouth activity. In addition to indoor sources of lead, contaminated soil is tracked on shoes or feet and blown by air currents into homes, accumulating in household dust which is a major source of exposure for both children and adults. The purpose of this review is to determine standards presumed to be health protective for lead and dust in different countries. We find that many countries have no standards for lead in soil and dust and rely on standards set by the World Health Organization or the US Environmental Protection Agency, and these standards may or may not be enforced. There is considerable variation in standards set by other countries.

Comparison of empirical and mechanistic blood lead models for children

Childhood exposure to lead can result in increased blood lead levels, which can have detrimental health effects. Models that can predict blood lead level based on exposure to floor and window sill dust lead at varying concentrations are useful tools for informing policy decisions. We compare an empirical model relating blood lead in children to the lead content of household dust, with a mechanistic model that simulates lead exposure in children through their daily activities. The empirical model is constructed using 1999–2004 NHANES data, while the mechanistic model is validated using 2011–2016 NHANES data. The models are evaluated at dust loadings ranging from 0.18 – 43 µg/ft2 and the resulting blood leads are compared. Specific demographic variables are chosen to simulate individuals are generated with “typical,” “high end,” and “low end” exposures in the empirical model; these are directly compared with the median, 95th, and 5th percentile results from the mechanistic model. For a child with “typical” lead exposure, the 95 % confidence interval for computed blood lead values contained the median blood lead value from the mechanistic model at all dust lead exposure levels considered. Similar results hold when comparing the 95th percentile to “high end” and 5th percentile to “low end”. The blood lead level computed by the mechanistic model increases more quickly with respect to dust loading than the empirical model, particularly at higher loadings. The empirical and mechanistic models generate similar blood lead distributions across the range of dust loadings considered, particularly at low loadings. The mechanistic model may be more appropriate for higher loadings due to limitations inherit in the structure of the empirical model.

The association between childhood blood lead levels and proximity to airports in Colorado

BackgroundIn October 2023, the U.S. Environmental Protection Agency announced a final endangerment finding that leaded aviation gasoline (avgas) contributes to air pollution that is harmful to public health. This study evaluates the evidence for a link between living in proximity to airports and children’s blood lead levels in Colorado.MethodsWe analyzed the association between childhood blood lead levels (BLLs) and proximity to airport point locations in children tested for lead in Colorado over a 10-year study period (2011–2020) using a correlated random effects model with bootstrapped standard errors (N = 56,002 observations, 47,322 individuals). Along with distance from airport point locations, we identified the number of days sampled children lived downwind of their nearest airport during the 60 days prior to their test date. We also adjusted the model for age, sex, detection limit, test type, sample order, seasonality, time, proximity to lead-releasing facilities, estimated monthly aircraft traffic, and demographic characteristics of the surrounding neighborhood.ResultsOur primary model estimates that living one mile (1.6 km) further from airport point locations decreases mean blood lead levels by 0.068 µg/dL. Additional analysis estimates that living one mile further from airport point locations decreases the odds of having a blood lead level ≥ 3.5 µg/dL by 13.2%.ConclusionOur results suggest that lead emissions from aircraft using leaded avgas have a small but statistically significant effect on the BLLs of children living near airport point locations in Colorado. While the risk from proximity to airports is likely less than the risks associated with deteriorating lead paint and dust, our findings highlight the value of lead testing in children who may be at risk of exposure from all sources, including those who live near airports.

Lead dust exposure and blood lead levels among workers in used battery recycling factories in Dar es salaam, Tanzania

Background: Used Lead Acid Battery (ULAB) recycling factories produce Lead, which brings health effects among workers. Lead is an environmental and occupational pollutant agent. Lead toxicity is one of the most prevalent occupational and environmental health problems in the world.1 Objective: The main objective of the surveillance was to determine lead exposure levels and associated health effects among workers in ULAB recycling factories in Dar es Salaam, Tanzania. Material and Methods: This was a cross sectional study conducted in two of the ULAB recycling factories (Factory A and Factory B) in Dar es Salaam. The Socio demographic characteristics from 149 workers in the two factories were assessed. Lead exposure levels in air and blood Lead level (BLL) was measured (n=60). Inductive Coupled Plasma Optical Emission Spectrometry (ICP-AOS) used for analysis of Lead exposure level and BLL data and control measure were analysed using SPSS version 23. Results and discussion: The arithmetic mean (AM) age was 30.56 years with standard deviation (SD) 8.66. The mean duration of employment was 82.24(69.55) and 47(57.09) months for Factory A and Factory B respectively. Geometric Mean (SD) for Pb level in air were 307.9(5.08) µg/m3 and 242.9(1.94) µg/m3 for factory A and factory B respectively, which were higher compared to the OEL value of 50 µg/m3by NIOSH and that of 0.5µg/m3 by WHO. The mean Blood Lead Level was 9.36 µg/dL and 17.30 µg/dL for Factory A Factory B respectively. The use of protective equipment was 2.70 % for respirators and 79.90% reported on being provided with a piece of cloth. Conclusion: The study concludes that higher levels of lead in air was associated with the recycling processes at ULAB recycling factories. Workers in these factories had inappropriate PPE in comparison with hazards exposed. The mean Blood Lead level of the workers for factory were higher than the CDC reference value of 5µg/dL whereas at these level workers may experience health effects.

Study of the levels of some heavy metals present in the cement dust of Al-Mergib factory

In this study, the concentrations of heavy metals (lead, nickel, and copper) in the cement dust of a factory were estimated using an Atomic Absorption Spectrophotometer technique. Three samples were taken from the factory chimney at different locations and times. The first sample revealed the highest concentration of elements during examination (on the upper part of the chimney) is lead (about 30.7 mg/l), nickel (6.9 mg/l), and copper (1.697 mg/l). The lead concentration decreased slightly in the second sample (mid-chimney), but it is still the most abundant element in this sample (30.1 mg/l). And in the third sample (below the chimney), the lead concentration decreased slightly (29.7 mg/l), then Cooper, and Nickel. All the metals studied were within the World Health Organization (WHO) limit nickel (200 mg/l) and copper (100 mg/l), except for lead (5 mg/l), higher than the permissible limit Keywords: Cement factory, Cement dust, Wet digestion, Heavy metals

Thiourea-assisted selective removal of arsenic from copper smelting flue dusts in NaOH solution

The selective removal of arsenic from copper smelting flue dusts is of great significance for environmental protection and resource recycling. This study employed thiourea assisted alkaline leaching to selectively extract arsenic from copper smelting flue dusts. The effects of NaOH concentration, thiourea concentration, temperature, leaching time and pulp density on the dissolution of arsenic, zinc, lead, copper and antimony in NaOH solution were studied. The results show that the addition of thiourea can effectively promote extraction of arsenic while inhibiting the leaching of zinc, lead and copper in copper smelting flue dust. Under the optimized leaching conditions, the leaching efficiencies of arsenic and antimony were 98.5% and 1.62%, respectively, while zinc, lead and copper were not leached. X-ray diffraction (XRD) analysis suggested that the addition of thiourea promoted the dissolution of insoluble arsenate minerals. The combined results of scanning electron microscopy (SEM), mineral liberation analysis (MLA), and X-ray photoelectron spectroscopy (XPS) demonstrated that thiourea prevented sulfide products from forming a coating on arsenic surface. This work has important implications for the development of processing technologies for arsenic-containing materials.

Children's lead exposure in the U.S.: Application of a national-scale, probabilistic aggregate model with a focus on residential soil and dust lead (Pb) scenarios

Lead (Pb) exposures from soil and dust ingestion contribute to children's blood lead levels (BLLs) in the United States. The U.S. Environmental Protection Agency (EPA)'s Strategy to Reduce Lead Exposures and Disparities in U.S. Communities and the Federal Action Plan to Reduce Childhood Lead Exposure describe multi-pronged collaborative approaches. These include reducing multi-media lead exposures nationally using analytical tools such as EPA's Stochastic Human Exposure and Dose Simulation model for lead [SHEDS-Pb; formerly known as SHEDS-IEUBK (Integrated Exposure Uptake Biokinetic model)], which was initially developed and applied with a focus on children's drinking water exposures. In this study we applied SHEDS-Pb to determine what residential soil Pb and dust Pb concentrations (individually and their sum) can keep BLLs of potentially exposed young children in the general U.S. population below specified values, considering aggregate exposures from water, soil, dust, food, and air. We considered two age groups (1 to <2 years and 2 to <6 years), two BLL values (5 μg/dL and 3.5 μg/dL), and two population percentiles (95th and 97.5th). Sensitivity analyses were conducted using several alternative model inputs and data sets, yielding 15 scenarios summarized in the paper. Of those scenarios, we focused on ones with the most recent science and available data. Modeled soil Pb concentrations by age group, population percentile and reference BLL scenarios for the focus scenarios ranged from 70 ppm to 220 ppm; and modeled dust Pb concentrations ranged from 110 ppm to 240 ppm. These results are consistent with current soil and dust Pb concentrations in the U.S. general population and are lower than most of the current U.S. Federal standards. Estimated BLLs compared well with measured BLLs from CDC's NHANES 2009–2016 (0–27 % relative error for focus scenarios). This analysis can be used to inform EPA and other federal Pb efforts.

The recovery of valuable components from secondary lead dust by a multi-step hydrometallurgical process

Multicomponent secondary lead dust (MSLD) is a significant resource that contains valuable metals such as lead, zinc, and cadmium, along with potentially harmful components such as salts (K, Cl) and As. In this study, an economic and efficient method was proposed for the recovery of MSLD, including desalination, sulfation roasting, water leaching, and zinc plate cementation. Firstly, desalination was conducted to remove K and Cl, and 90.4% of K and 76.5% of Cl were selectively removed with a low NaOH consumption of 1.00 g/t dust at 40 °C and pH 7.5. Subsequently, the desalted residue, enriched with Cd, Zn, As, and Pb, was treated by H2SO4 roasting, which facilitated the transformation of arsenites and sulfides into As2O3 and sulphates. The recovery of As was achieved with a volatilisation efficiency of 93.2% as As2O3 using 65% H2SO4 at 350 °C. Finally, the recovery of Cd was accomplished through zinc plate cementation, resulting in the cementation of 99.4% Cd as Cd sponge with a purity of 96.3%. The residue from water leaching and cemented solution gathered 98.2% Pb and 94.6% Zn. The multi-step process realised the selective removal of K and Cl salts as well as the comprehensive recovery of valuable elements.

Pesticide, allergen, PCB, and lead measurements in childcare centers located on tribal lands in the Pacific Northwest, United States

BackgroundChildren’s potential exposures to chemical and biological agents in tribal childcare centers are not well characterized.Objectives(1) The environmental health of childcare centers in Portland Area Indian Country was characterized by measuring selected pesticides, polychlorinated biphenyls (PCBs), allergens, and lead (Pb) in outdoor soil and indoor dust. (2) We compared our results to other studies of childcare centers in both the United States and globally.MethodsAt 31 tribal childcare centers in Washington, Oregon, and Idaho, we collected indoor dust and outdoor soil samples from at least one classroom, multipurpose room, and outdoor play area. Number of rooms sampled depended on facility size. Surface wipes were collected from the floor, play/work surface, and windowsill and analyzed for selected pesticides and PCBs. Vacuum samples were collected from the floor and analyzed for selected allergens. Lead was measured in surface wipes and outdoor soil collected at 11 centers. A questionnaire collected information on demographics, cleaning habits, and pesticide usage.ResultsAt least one pesticide was measured at all childcare centers. cis-Permethrin (surface wipes: 0.003–180 ng/cm2), trans-permethrin (surface wipes: 0.002–200 ng/cm2) and piperonyl butoxide (surface wipes: 0.001–120 ng/cm2) were measured in all centers. Lead was measured in most surface wipes (<0.25–14 ng/cm2) and all outdoor soil samples (8.4–50 mg/kg). Aroclors 1242 and 1254 were detected on indoor surfaces in three centers at very low loadings. Allergen residues were measured at very low concentrations in vacuum dust samples (Der p 1: <0.012–0.12 µg/g; Der f 1: <0.012–0.09 µg/g; Mus m 1: <0.002–10.055 µg/g). In general, we observed lower levels of chemical and biological agents than what has been reported previously.SignificanceBy understanding the environmental health of childcare centers, we can better understand the role of child-specific environments in promoting children’s health and well-being.Impact statementTo our knowledge, this is the first study to characterize the environmental health of tribal childcare centers in the Pacific Northwest. Combined with the information we have on childcare centers from around the world, this study expands our knowledge on young children’s potential exposures to chemical and biological agents in locations where they spend significant amounts of time.

Monte Carlo-based probabilistic risk assessment for cement workers exposed to heavy metals in cement dust.

This study assessed the carcinogenic and non-carcinogenic health risks of cement plant workers exposed to chromium (Cr), arsenic (As), cadmium (Cd), and lead (Pb) in cement dust using a probabilistic approach. Air samples were collected according to NIOSH 7900 and OSHA ID-121 methods and analyzed by an graphite furnace atomic absorption spectrometer. The EPA inhalation risk assessment model and Monte Carlo simulation were utilized to assess the health risks. Sensitivity analysis was used to determine the influencing parameters on health risk. The average concentrations of As and Pb exceeded the occupational exposure limit (OEL), reaching a maximum of 3.4 and 1.7 times the OEL, respectively, in the cement mill. Individual metals' cancer risk exceeded the 1E-4 threshold in ascending order of Cd < As < Cr. The mean cancer risk of Cr ranged from 835E-4 (in raw mill) to 2870E-4 (in pre-heater and kiln). Except for Cd, the non-cancer risk of metals exceeded the standard (hazard index, HQ = 1) in the ascending order of Pb < As < Cr. The mean HQ of Cr ranged from 162.13 (in raw mill) to 558.73 (in pre-heater and kiln). After adjusting for control factors, the cancer and non-cancer risks remained over the respective recommended levels. Sensitivity analysis revealed that the concentration of Cr was the most influential parameter on both carcinogenic (78.5%) and non-carcinogenic (88.06%) risks. To protect the health of cement factory employees, it is recommended to minimize cement dust emissions, implement job rotation, and use raw materials with low levels of heavy metals.

Risk assessment of lead exposure in radiology personnel in Menoufia hospitals, Egypt

Lead shielding is used as a guard against scatter radiation. Lead aprons can emit particulate lead into the occupational environment, resulting in the accumulation of lead dust on the skin and garments of workers. This study aimed to assess the risk of lead exposure among radiologists working in the radiology departments by estimating hair and blood lead levels. A total of 40 radiology personnel (18 wearing aprons and 22 not wearing aprons) with a comparable control group (20 personnel not working in a radiology department) underwent a pre-designed questionnaire with estimation of blood and hair levels. The hair and blood lead levels in radiologists wearing aprons were significantly higher than those of the control group and that of the radiologist not wearing aprons. The lead levels in hair and blood were correlated significantly with the duration of wearing aprons in years and weekly working hours. Health care workers in radiology departments demonstrated high hair and blood levels that were higher among workers wearing aprons than those not wearing protective equipment. Hair lead levels can be detected quickly, cheaply, and non-invasively, and could be a helpful screening test for occupational exposure.

Lead pollution-related health of children in China: Disparity, challenge, and policy

Lead (Pb) is a neurotoxic metal, and no level of lead exposure is safe for children. China has still experienced problems on child lead poisoning even though the Chinese government has phased out leaded gasoline since 2000. The underlying problem affecting the lead pollution-related health of children in China remains to be comprehensively investigated. It is found that although the significant decline of BLLs, as the Geometric Mean (GM), from 91.40 μg/LGM in 2001 to 37.52 μg/LGM in 2018 is observed, the average BLLs of children are still above 50 μg/L or more [average 59.70 (60.50–65.02, 95 % CI) μg/LGM] after phasing out leaded gasoline since 2000 in China. Lead exposure causes 29.67 MID per 1000 children with a loss of 98.23 (59.40–146.21, 95 % CI) DALYs per 1000 in China, which is greater than the levels reported from the Western Pacific Region and other low- and middle-income countries. A significant correlation is observed between the number of child crimes (NoCCs) and the outcomes of long-term lead exposure for children in China. Although the disparities in BLLs in China are strongly influenced by unequal distributions of potential multi-lead related sources (soil lead, PM2.5 lead, dust lead), unbalance development of local industrialization and economies, as well as incorrect health care for younger children, the notable emissions from coal combustion (CC) and non-ferrous metals (NMS) exploitation dominate the crucial sources of low-level lead exposure to children after phasing out leaded gasoline in China currently. Faced with the unequal and disparate distribution of BLLs in China, the big bottleneck is to decrease the BLLs exertions of 36–45 μg/L in the next few decades. The Chinese government needs to make more efforts on developing more strict guidelines, implementing more policy strategies on prevention and management of blood Pb poisoning, and monitoring the nationwide changes in children's BLLs continuously.

Construction of a geoecological map of dust particles transfer from the surface of the Shymkent lead (plumbum) factory dump

The study of horizontal migration of heavy metals is relevant for Shymkent city. In 1934, lead processing began, and sludge waste was stored on the territory of the lead factory. Ameliorative or other structures capable of reducing dust emissions have not been built around the lead dump, allowing lead dust to freely spread over long distances from the SPZ (sanitary protection zone). In this article, the horizontal migration of lead dust was studied based on climatic and calculated data by building a physical model; in addition, a geoecological map was built. This work has practical significance for further ecological and geochemical assessment of soils for the content of heavy metal concentrations, since it visually characterizes the spread of lead dust along the wind rose. To build a geoecological map of the transfer of impurities, we are faced with the task of determining the rate of settling of hovering particles and their distributions depending on the masses of particles and wind speed. To determine the rate of deposition of lead particles in the atmosphere, we need to study the shape of lead, background meteorological situation, particle diameter, solid particle density, medium density and dynamic viscosity of the medium. The removal of dust particles from the surfaces of ash and slag dumps of industrial facilities into the atmosphere under the influence of wind erosion, followed by their deposition on the soil, is one of the most common ways of polluting the territories of industrial facilities. As a result of the calculations, the surface concentration of dust particles was derived and a geoecological map was compiled. Keywords: geoecological map, lead dumps, assessment of dust emissions, horizontal migration of heavy metals, physical model of transport and scattering.

Estimating the proportion of bioaccessible lead (BaPb) in household dust wipe samples: a comparison of IVBA and PBET methods

Established methods for using standardized dust wipes to collect and measure total lead in household dust are readily available but the use of dust wipes to measure bioaccessible lead (BaPb) is less clear. This study compared two in vitro methods for estimating the proportion of BaPb in dust collected into dust wipes including the US-EPA’s in-vitro bioaccessible assay (IVBA) method at two pH (1.5 and 2.5) values; and the physiologically based extraction test (PBET 2.5 pH). Two types of simulated household dust samples (Pb-soil contaminated and Pb-paint contaminated) each with three Pb concentrations were created. Equal amounts of simulated dust were applied to a smooth surface and collected following the standard EPA dust wipe protocol and were analyzed for BaPb and total Pb (ASTM-E1644-17, ICP-OES). Estimated BaPb levels differed significantly by the method of extraction. Mean percent BaPb were IVBA pH 1.5, > 90% (Pb-paint) and 59–63% (Pb-soil); IVBA pH 2.5 78–86% (Pb-paint) and 45–50% (Pb-soil); PBET pH 2.5 56 to 61% (Pb-paint) and 41–50% Pb-soil). Particularly for lead-paint contaminated dust, PBET showed significantly greater discrimination as suggested by the broader range of BaPb values and closer approximation to total lead concentrations in simulated household dust samples.

Relationships among Environmental Lead in Playground Soils and Dust and Blood Lead of Children in Muncie, Indiana, USA

Relationships among Environmental Lead in Playground Soils and Dust and Blood Lead of Children in Muncie, Indiana, USA

Pollution-free recycling of lead and sulfur from spent lead-acid batteries via a facile vacuum roasting route

Traditional pyrometallurgical recovery of spent lead-acid batteries (LABs) requires a temperature higher than 1000 °C, with accompanying hard-to-collect wastes such as lead dust and sulfur oxides. Against this background, sodium carbonate (Na2CO3) was proposed as a low-cost, safe, and non-toxic reagent for recycling the high-risk environmental elements lead (Pb) and sulfur (S), in spent LAB lead paste, enabling the one-step conservation of multi-component Pb species, including lead sulfate (PbSO4), metallic lead (Pb), and lead dioxide (PbO2), to lead oxide (PbO) and sodium sulfate (Na2SO4). The possible reaction pathways of Pb and S species in vacuum roasting was confirmed by Gibbs free energy reaction with an estimated average activation energy of 272.5 kJ/mol. The insoluble PbO in the reaction product (PbO/Na2SO4/Na2CO3) can be recycled by vacuum filtration, while Na2CO3 and Na2SO4 were separated using a carbonation method. Life cycle assessment revealed that for recycling 1.0 t of spent LABs, the vacuum roasting can reduce the carbon footprint −2.1 × 103 kg CO2 eq, promoting global decarbonization. The designed route is highlighted with waste-free production and is outlined by the twelve principles of green chemistry, showing its great engineering application potential for spent LAB recycling.

Lead-Dust Contamination on Radiation Protection Apparel

PurposeTo evaluate the prevalence of surface lead-dust contamination on radiation protection apparel (RPAs) in the radiology department and compare findings with those from other studies of RPA lead-dust contamination. Materials and MethodsA survey of RPAs was conducted between June and December 2021 in radiology departments at a tertiary-care university hospital. A convenience sample of RPAs located on wall-mounted racks outside the angiography suite and emergency department was surveyed. Surface lead dust on RPAs was detected using a rapid qualitative test. ResultsA total of 69 RPAs included full-length frontal lead aprons (n = 11), full-length frontal lead aprons (n = 25) with thyroid collars (n = 25), and thyroid collars alone (n = 8). Garments consisted mainly of a lead/antimony composite core with a 0.5-mm lead equivalency. One RPA failed radiologic quality inspection, and 8 garments were in poor or worn condition. The overall prevalence of surface lead-dust contamination on RPAs was 60.9% (95% CI, 49.1%–71.5%) and was significantly (P = .0035) higher on thyroid collars (78.8% [95% CI, 62.2%–89.3%]) than on lead aprons (44.4% [95% CI, 29.5%–60.4%]). ConclusionsA high prevalence of surface lead-dust contamination was detected on RPAs using a rapid qualitative test. There is currently no established safe level of lead, and these findings suggest RPAs be monitored frequently not only for physical defects limiting radiation protection but also for lead-dust contamination.

Determining the geochemical fingerprint of the lead fallout from the Notre-Dame de Paris fire: Lessons for a better discrimination of chemical signatures

On 2019, the fire of Notre-Dame de Paris cathedral (“NDdP”) spread an unknown amount of lead (Pb) dust from the roof of the cathedral over Paris. No data describing the geochemical fingerprint of the roof lead, as well as no particle collected during the fire, were available: a post-hoc sampling was performed. To discriminate the potential environmental impact of the fire from multiple Pb sources in Paris, it was mandatory to define unequivocally the fire dust geochemical signature. A dedicated and in hindsight geochemistry-based strategy was developed to eliminate any source of potential contamination due to sampling substrates or previously deposited dust. Radiogenic Pb isotopic signatures (206Pb/207Pb and 208Pb/206Pb ratios) and elemental ratios were determined in 23 Pb-rich samples collected inside NDdP. We determined that the dust collected on wood substrates on the first floor was most representative of fire emissions. These samples were the analyzed for the 4 Pb isotopes (204, 206, 207, 208) and the fire dust signature is characterized by ratio values of 206Pb/207Pb: 1.1669–1.1685, 208Pb/206Pb: 2.0981–2.1095, 208Pb/204Pb: 38.307–38.342, 207Pb/204Pb: 15.633–15.639 and 206Pb/204Pb: 18.242–18.275. In addition, the fire dust presents typical element-to-Pb ratio. This fingerprint was compared to the signatures of the known local Pb sources. The geochemical fingerprint of the fire is significantly different from that of the dominant urban Pb source. This will allow future evaluation of the contribution of the fire to Paris Pb pollution and of the real extent of the area affected by the Pb-containing dust plume. Moreover, the geographical origin of Pb used for the roof restauration and the spire building was identified. These findings open new ways to study the Pb sources in historical monuments for environmental impacts evaluation, as well as for historical perspectives.

Concentrations of lead in the dust of some fuel stations in Salah al-Din Governorate

This study was carried out in the city of Tikrit and its environs, where environmental pollution with lead was studied in some governmental fuel stations in Salah al-Din Governorate, where cars often gather for refueling, resulting in vehicle exhausts varying proportions of the pollutants emitted from them, including the element lead.&#x0D; The study was divided to include five sites, four gas stations and a fifth group for control, which are: the old Tikrit gas station, Fateh al-Futuh fuel station (al-Qadisiyah station), al-Dour gas station and the martyr Umayya Jibara station (al-Alam station), and the fifth site (the control site) In the Naamah area outside the preservation center on the roads leading to the Kirkuk governorate, which is approximately 40 km away from the research project stations.&#x0D; The text of the research is to take samples from the dust scattered on the floor of these stations and the control group for a period of six months with a sample per month, from November 2019 to April 2020.&#x0D; The results the study were determined by measuring the concentrations of lead present in the dust belonging to these stations by means of a Flame Atomic Spectrometer.&#x0D; The results showed that there were significant differences between the stations and the control group, so the results recorded the highest concentration of lead in dust for the average of the stations during the six months (0.1543 ±0.01112 mg/L) in the Al-Dour governmental fuel station, and the lowest concentration (0.0831 ± 0.0708 mg / L) in the Fath Al Futuh station.&#x0D; (Al-Qadisiyah station), while the concentration of the control group was (0.0387 ±0.0316 mg/L). The reason for the high results of these measurements on the control group may be attributed to the high traffic movement of cars, the lack of vegetation and the frequency of dust storms that the study area is exposed to from time to time, in addition to other industrial activities in the area under study.