Measured Lead Concentrations Research Articles

Unveiling the Health Ramifications of Lead Poisoning: A Narrative Review.

The presence of lead (Pb) in children's toys and paint is a significant global public health concern. Numerous studies conducted worldwide have measured lead concentrations in these products. This article aims to examine the research findings and shed light on the implications for human health, including legal consequences and public awareness. Despite regulations on lead levels in polyvinyl chloride (PVC) paints and children's toys in many countries, several reviewed documents indicate that these products often contain substantial amounts of lead, frequently surpassing legal limits. Particularly high levels of lead in paints have been found in countries such as China, Thailand, and Brazil. It is crucial to raise awareness among parents by educating them about this issue and empowering them to take proactive measures to protect their children from lead poisoning associated with toys and colored paints. There is also global support for eliminating lead pigments and regulating the amount of lead in PVC toys.

Lead exposure is correlated with reduced nesting success of an urban songbird

Lead exposure is a concern in urban ecosystems, with physiological and behavioral effects well documented in humans. Wildlife inhabiting urban ecosystems are also exposed to lead, yet little work has documented the sublethal effects of lead exposure in urban wildlife. We studied northern mockingbirds (Mimus polyglottos) in three neighborhoods of New Orleans, Louisiana, two with high soil lead and one with low soil lead, to better understand how lead exposure may influence mockingbirds' reproductive biology. We monitored nesting attempts, measured lead concentrations in blood and feathers of nestling mockingbirds, documented egg hatching and nesting success, and assessed rates of sexual promiscuity in relation to neighborhood soil lead levels. We found that nestling mockingbirds’ blood and feather lead levels reflected the soil lead levels of their neighborhoods and nestling blood lead levels were similar to those of adult mockingbirds in the same neighborhoods. Nest success, as evaluated by daily nest survival rates, was higher in the lower lead neighborhood. Clutch sizes varied substantially across neighborhoods, but rates of unhatched eggs did not covary with neighborhood lead levels, suggesting that other drivers are influencing variation in clutch sizes and hatching success in urban habitats. At least one-third of nestling mockingbirds were sired by an extra-pair male, and there was no relationship between extra-pair paternity rates and neighborhood lead levels. This study provides insight on how lead contamination may influence reproduction in urban-dwelling wildlife and suggests that nestling birds could serve as useful bioindicators of lead levels in urban neighborhoods.

Expanding the use of portable XRF to monitor lead exposure in an Australian duck species two decades after a ban on lead shot

There is growing worldwide recognition of the threat posed by toxic lead for wildlife and humans. Lead toxicity from ammunition has been shown to be a threat to waterbirds across the globe. Lead shot was banned for all waterfowl hunting in Victoria, Australia, in 2002. However, no assessments of lead exposure in Australian waterfowl have been published since the 1990s. Our aim was to estimate contemporary lead exposure via measuring bone lead concentrations in a harvested dabbling duck, the Pacific black duck (Anas superciliosa). We collected wings from 77 Pacific black ducks, spanning 2018 (n = 30) and 2021 (n = 47), from nine sites with long-term histories of regular waterfowl hunting. We sought to validate portable X-ray fluorescence (XRF) for this purpose by taking a piece of humerus bone from each bird, and measuring lead concentration (mg/kg), first via non-destructive XRF and then via destructive inductively coupled plasma mass spectrometry (ICP-MS) and validated the relationship via regression analysis. Portable XRF bone lead measurement demonstrated a strong correlation with ICP-MS results using root-transformed regression (R2 = 0.85). Greater than 92 % of ducks had only background lead exposure (<10 mg/kg). When compared to historical studies in the same species at similar field sites from the 1990s, lead exposure levels were considerably lower, with mean lead concentrations ∼2-fold lower (3.7 c.f. 7.7 mg/kg), and the frequency of birds with severe lead exposure (>20 mg/kg) ∼3-fold lower (2.6 c.f. 7.5 %). Our results confirm that portable XRF is a useful option for measurement of bone lead in Australasian waterbird species. Our findings also demonstrate that a ban on the use of lead shot around 20 years ago has been associated with a substantial reduction in lead exposure in at least one species of waterfowl.

Trace Level Quantification of Lead in Michigan Lake Water Using Differential Pulse Stripping Voltammetry: A Comparative Study on the Usage of Mercury Based Electrodes Vs Solid State Gold Electrodes

The concentration of lead in fresh-water samples from the southern shoreline of Lake Michigan was analysed and compared using two different cell-stands: Controlled Growth Mercury Electrode (CGME) and voltammetry cell stand with disk type gold electrode. Clearly visible Lead (II) peaks at -395 mV and 130 mV were obtained with CGME and Au electrodes respectively using anodic stripping voltammetry (ASV) technique. Sensitivity, reproducibility, and ease of usage were differentiated for each method. While the measured lead concentration was 2.4 ppb using CGME set-up a closely similar concentration of 2.7 ppb was obtained with the gold disk electrode set-up and thereby confirms the availability of Hg-free detection of lead. The sensitivity obtained from the standard addition curve using the gold electrode was also over twice that of the CGME. The difference in background currents was attributed to the different electrode materials, bulk diffusion in electrolyte of lead ions, electrode-electrolyte interface and the relative surface areas of the electrode surface. Even after repeated polishing of gold electrodes in each run, its inherent sensitivity makes it an ideal candidate for lead determinations with no further requirement of handling the hazardous mercury wastes.

Trace Analysis of Lead in Michigan Lake Water Using Differential Pulse Stripping Voltammetry: A Comparative Study on the Usage of Controlled Growth Mercury Electrodes Vs Solid State Gold Electrodes

The concentration of lead in fresh-water samples from the southern shoreline of Lake Michigan was analyzed and compared using two different cell-stands: Controlled Growth Mercury Electrode (CGME) and voltammetry cell stand with disk type gold electrode. Clearly visible Lead (II) peaks at -395 mV and 130 mV were obtained with CGME and Au electrodes respectively using anodic stripping voltammetry (ASV) technique [1-4]. Sensitivity, reproducibility, and ease of usage are compared and reported for each method. While the measured lead concentration was 2.4 ppb using CGME set-up a closely similar concentration of 2.7 ppb was obtained with the gold disk electrode set-up. The sensitivity obtained from the standard addition curve using the gold electrode was over twice that of the CGME. The difference in background currents was attributed to the different electrode materials, bulk diffusion in electrolyte of lead ions, electrode-electrolyte interface and the relative surface areas of the electrode surface. The main convenience associated with the CGME was the fresh electrode surface provided by each new drop, so no further electrochemical cleaning was needed. However, even after repeated polishing of gold electrodes in each run, its inherent sensitivity makes it an ideal candidate for lead determinations with no further requirement of handling the hazardous mercury wastes. Figure 1

Concentrations and isotopic analysis for the sources and transfer of lead in an urban atmosphere-plant-soil system

Lead pollution has attracted significant attention over the years. However, research on the transfer of lead between urban atmospheric particles, soils, and plants remains rare. We measured lead concentrations and lead isotope ratios in total suspended particles (TSP), soil, and plants in an urban wetland in Beijing. The study period was September 2016–August 2017- covering all four seasons. The concentrations of lead in the atmospheric particles vary from 3.13 to 6.68 mg/m3. It is significantly higher in autumn than that in spring and summer (P < 0.05). There is also a significant difference between summer and winter (P < 0.05). The soil lead concentrations range from 57 to 114 mg/kg, with the highest concentration in spring, followed by summer, winter and autumn. The lead concentrations are 1.28–7.75 mg/kg in plants. The concentration was highest in spring and significantly higher than in summer. The bioaccumulation factor of Phragmites australis was 0.064 (<0.1), indicating that lead is not easily transferred to plants. Unlike the bioaccumulation factors, translocation factors have much higher values, indicating a higher transfer within the plants. Results also indicate an interesting seasonal pattern with almost 97% of lead in plants during spring being of atmospheric origin, whereas in autumn, soilborne sources contribute almost 94%. The isotopic compositions of lead in the urban atmosphere-soil-plant system show that lead pollution results from the mixing of geogenic and anthropogenic materials. Vehicle exhaust, crustal rocks and ore deposits are likely primary sources of lead pollution within the study domain.

Validity of a portable X-ray fluorescence device for analyzing field dust wipe samples for lead

Interior dust lead loadings on floors and windowsills are reliable predictors of a child’s blood lead level and an important predictor in “clearance testing” of residences. The portable X-ray fluorescence device is an alternate technique that can provide fast, accurate, and precise results regarding the presence of dust lead hazards in residences. In this paper, we tested the comparability of the portable X-ray fluorescence device against Inductively Coupled Plasma Mass Spectrometry, using the newer lead hazard standards for dust wipe samples. Dust wipe samples (n = 109) collected from floors and interior windowsills of 13 homes were tested by means of a portable X-ray fluorescence device and subsequently analyzed for lead using Inductively Coupled Plasma Mass Spectrometry. Considering Inductively Coupled Plasma Mass Spectrometry as the “gold standard,” the portable X-ray fluorescence device produced an average false negative rate of 27.3% at the new dust lead hazard standards of 10 μg/ft2 for floors, and 100 μg/ft2 for windowsills. There were no false positive results from the portable X-ray fluorescence device at the new dust lead hazard standards. A Bland Altman analysis showed that 96.3% of the data points were within the lower and upper acceptable limits of agreement. The results of the study suggested that the portable X-ray fluorescence device has a good agreement with the Inductively Coupled Plasma Mass Spectrometry method at lower lead concentrations and is appropriate for measuring lead concentrations in field dust wipe samples from homes where lead concentrations are in a lower range.

Work Task Association with Lead Urine and Blood Concentrations in Informal Electronic Waste Recyclers in Thailand and Chile.

The informal recycling of electronic waste (“e-waste”) is a lucrative business for workers in low- and middle-income countries across the globe. Workers dismantle e-waste to recover valuable materials that can be sold for income. However, workers expose themselves and the surrounding environment to hazardous agents during the process, including toxic metals like lead (Pb). To assess which tools, tasks, and job characteristics result in higher concentrations of urine and blood lead levels among workers, ten random samples of 2 min video clips were analyzed per participant from video recordings of workers at e-waste recycling sites in Thailand and Chile to enumerate potential predictors of lead burden. Blood and urine samples were collected from participants to measure lead concentration. Boosted regression trees (BRTs) were run to determine the relative importance of video-derived work variables and demographics, and their relationship with the urine and blood concentrations. Of 45 variables considered, five job characteristics consisting of close-toed shoes (relative importance of 43.9%), the use of blunt striking instruments (14%), bending the back (5.7%), dismantling random parts (4.4%), and bending the neck (3.5%) were observed to be the most important predictors of urinary Pb levels. A further five job characteristics, including lifting objects <20 lbs. (6.2%), the use of screwdrivers (4.2%), the use of pliers/scissors (4.2%), repetitive arm motion (3.3%), and lifting objects >20 pounds (3.2%) were observed to be among the most important factors of blood Pb levels. Overall, our findings indicate ten job characteristics that may strongly influence Pb levels in e-waste recycling workers’ urine and blood.

Feasibility of Lead Exposure Assessment in Blood Spots using Energy-Dispersive X-ray Fluorescence.

Collecting blood spots from newborns is a common procedure used to diagnose multiple health conditions. Fingerstick blood samples are routinely collected from children to diagnose elevated blood lead levels. In our study, we wanted to test the feasibility of using a high-power energy-dispersive X-ray fluorescence (EDXRF) device to accurately measure the concentration of lead in blood spots. We created spotted standards of a known concentration of lead on a filter paper at different volumes and concentrations. We determined the detection limit for lead through repeated measurements of our standards and calibration line slopes. We also tested the variability of the measured lead concentration across procedures and spotted blood volumes and found no significant additions to uncertainty in measurements. Finally, we compared blood lead concentrations measured by EDXRF and atomic absorption spectroscopy (AAS) and found EDXRF to be a significant predictor of blood lead (n = 22, R = 0.98, p value <0.001) with an average detection limit of 1.7 μg/dL of blood lead. This detection limit is similar to that of the AAS technique, which is commonly used in clinical testing laboratories for blood lead surveillance. These findings provide a proof of concept that blood spots measured by EDXRF may be used as a surveillance tool for lead exposure, even at elevated blood lead levels of 2-3 μg/dL.

Construction of a sensitive and specific lead biosensor using a genetically engineered bacterial system with a luciferase gene reporter controlled by pbr and cadA promoters

BackgroundA bacterial biosensor refers to genetically engineered bacteria that produce an assessable signal in the presence of a physical or chemical agent in the environment.MethodsWe have designed and evaluated a bacterial biosensor expressing a luciferase reporter gene controlled by pbr and cadA promoters in Cupriavidus metallidurans (previously termed Ralstonia metallidurans) containing the CH34 and pI258 plasmids of Staphylococcus aureus, respectively, and that can be used for the detection of heavy metals. In the present study, we have produced and evaluated biosensor plasmids designated pGL3-luc/pbr biosensor and pGL3-luc/cad biosensor, that were based on the expression of luc+ and under the control of the cad promoter and the cadC gene of S. aureus plasmid pI258 and pbr promoter and pbrR gene from plasmid pMOL30 of Cupriavidus metallidurans.ResultsWe found that the pGL3-luc/pbr biosensor may be used to measure lead concentrations between 1–100 μM in the presence of other metals, including zinc, cadmium, tin and nickel. The latter metals did not result in any significant signal. The pGL3-luc/cad biosensor could detect lead concentrations between 10 nM to 10 μM.ConclusionsThis biosensor was found to be specific for measuring lead ions in both environmental and biological samples.

Lead Contamination in Opium, Opium Tincture, and Methadone Oral Solution, in Iran.

BackgroundThe present study is conducted with the aim to assess the lead contamination in opium tincture, methadone oral solution, and opium.Methods10 samples from each of the matters of opium tinctures, methadone oral solutions, and opium (provided by the Law Enforcement Force of the Islamic Republic of Iran) were collected. Then, an atomic absorption spectrophotometer (AAS) was used to measure lead concentration in each of the samples. Data were analyzed using the SPSS software. A P value of 0.05 or less was considered to be statistically significant (Two-tailed).FindingsIn this study, the amount of lead measured in all samples was equal or less than 5 parts per million (ppm) and the only exception was the lead level of 5.6 ppm in one of the opium tincture samples, which was slightly higher than the standard lead level.ConclusionThe results of the current study showed that lead was present in opium tincture, methadone oral solution, and opium, but it was not in toxic levels. It is reasonable for opium derived medicinal products, but the low levels of lead in opium may need to be addressed at different times in different regions of the country.

Trends of lead in atmospheric air

In the article, trends of lead content in atmospheric air of background territories and cities of Belarus according to NSEM data and their correlation with trends of lead content in the atmospheric air of cities and background territories of Europe and the USA are analyzed. Clear downward trends in lead content in the atmospheric air of the background territories of Belarus are shown: the average annual concentration of lead has decreased over the period from 1990 to 2015 by 77 %. According to EMEP stations measuring data having a continuous series of lead observations in atmospheric air since 1990, the mean annual lead content in atmospheric air at these stations decreased till 2013 on average by 86 %. A downward trend in the lead content was observed in the air of Belarusian cities and of some countries of Europe. The most significant decrease in lead content occurred in the USA, where the average annual maximum 3-month concentration decreased from 1990 to 2016 by 99 %. The relationship between trends in lead levels with trends of anthropogenic emissions is analyzed. Differences between the measured lead concentrations and calculated values by dispersion models are shown, which may be due to the incompleteness of the inventory of lead emissions in a number of countries, as well as the significant contribution of other sources of emission in addition to anthropogenic sources of lead emission into the atmosphere. To identify the reasons for these discrepancies, which may be related to the presence of unrecorded anthropogenic sources, secondary and natural sources, and other factors, additional research is needed.

Acute and Chronic Lead Exposure in Four Avian Scavenger Species in Switzerland.

Despite irrefutable evidence of its negative impact on animal behaviour and physiology, lethal and sublethal lead poisoning of wildlife is still persistent and widespread. For scavenging birds, ingestion of ammunition, or fragments thereof, is the major exposure route. In this study, we examined the occurrence of lead in four avian scavengers of Switzerland and how it differs between species, regions, and age of the bird. We measured lead concentration in liver and bone of the two main alpine avian scavengers (golden eagle Aquila chrysaetos and bearded vulture Gypaetus barbatus) over the entire area of the Swiss Alps and two of the main avian scavengers occurring in the lowlands of Switzerland (red kite Milvus milvus and common raven Corvus corax). Of those four species, only the bearded vulture is an obligate scavenger. We found that lead burdens in the two alpine avian scavengers were higher than those found for the same species elsewhere in Europe or North America and reached levels compatible with acute poisoning, whereas lead burdens of the two lowland avian scavengers seemed to be lower. Several golden eagles, but only one red kite with abnormally high bone lead concentrations were found. In all four species, a substantial proportion of birds had elevated levels which presumably represent recent (liver lead levels) or past (bone lead levels) uptake of sublethal doses of lead.

DETERMINATION RESULT OF LEAD IN ANIMALS AND ENVIRONMENTAL SAMPLES

Due to negligent use and disposal of lead containing sources including acid and alkali batteries with lead conductor, vehicle accumulators in last years, environment has been polluted greatly and it becomes the cause of animal poisoning. Heavy metals are dangerous because of their persistence and toxicity. Soil behaves as a sink of heavy metals by aerial deposition of particles emitted by human activities. The aims of this work were to identify the levels of lead in accumulator processing plant and city areas and animals. A total of 60 blood samples were collected in the vicinity of Ulaanbaatar and measured lead concentrations using equipment LeadCare II. Detection limit of LeadCare II for blood lead concentration ranges between 3.3 and 65 μg/dl. Measurements were made in three replicates using the samples, which were diluted by 10 to 100 fold and about 180 units of analysis was carried out. According to our study lead concentration in blood from livestock populations in the vicinity of Khonkhor lake, Nalaikh district is greater up to 52.9 ppm and the concentration in the soil around the factories is 30 fold higher. High lead content were found in soil and livestock animal blood samples of accumulator processing plant, which have correlated positively between them. But lead concentration in the blood sample from animals, which in areas might be free from lead pollution, was higher than acceptable level. In further studies on contamination resources are required.

Exposure to Low Levels of Lead in Utero and Umbilical Cord Blood DNA Methylation in Project Viva: An Epigenome-Wide Association Study.

Background:Early-life exposure to lead is associated with deficits in neurodevelopment and with hematopoietic system toxicity. DNA methylation may be one of the underlying mechanisms for the adverse effects of prenatal lead on the offspring, but epigenome-wide methylation data for low levels of prenatal lead exposure are lacking.Objectives:We investigated the association between prenatal maternal lead exposure and epigenome-wide DNA methylation in umbilical cord blood nucleated cells in Project Viva, a prospective U.S.-based prebirth cohort with relatively low levels of lead exposure.Methods:Among 268 mother–infant pairs, we measured lead concentrations in red blood cells (RBC) from prenatal maternal blood samples, and using HumanMethylation450 Bead Chips, we measured genome-wide methylation levels at 482,397 CpG loci in umbilical cord blood and retained 394,460 loci after quality control. After adjustment for batch effects, cell types, and covariates, we used robust linear regression models to examine associations of prenatal lead exposure with DNA methylation in cord blood at epigenome-wide significance level [false discovery rate ].Results:The mean [standard deviation (SD)] maternal RBC lead level was 1.22 (0.63) . CpG cg10773601 showed an epigenome-wide significant negative association with prenatal lead exposure ( per doubling increase in lead exposure; ) and was annotated to C-Type Lectin Domain Family 11, Member A (CLEC11A), which functions as a growth factor for primitive hematopoietic progenitor cells. In sex-specific analyses, we identified more CpGs with among female infants () than among male infants (). One CpG (cg24637308), which showed a strong negative association with prenatal lead exposure among female infants ( per doubling increase in lead exposure; ), was annotated to Dynein Heavy Chain Domain 1 gene (DNHD1) which is highly expressed in human brain. Interestingly, there were strong correlations between blood and brain methylation for CpG (cg24637308) based on another independent set of samples with a high proportion of female participants.Conclusion:Prenatal low-level lead exposure was associated with newborn DNA methylation, particularly in female infants. https://doi.org/10.1289/EHP1246

A pilot study to assess lead exposure from routine consumption of coffee and tea from ceramic mugs: comparison to California Safe Harbor Levels

BackgroundLead (Pb) is a pervasive metal that can be found in, and potentially leached from, ceramics, particularly into acidic foods and beverages. The purpose of this study was to investigate potential lead exposure from coffee and tea consumption, given that both are acidic and routinely consumed from ceramic mugs. We measured the concentration of lead in coffee and tea at two different time points brewed in five readily available mugs known to contain lead. Results were compared to EPA’s action level for drinking water and FDA’s allowable level for bottled water. The measured concentrations, along with consumption patterns, were also used to calculate potential daily lead doses, which were compared to California’s Safe Harbor Levels under Proposition 65. Additionally, we estimated changes in adult and fetal blood lead levels using EPA’s Adult Lead Methodology model.FindingsThe results of this pilot study suggest that lead in ceramic mugs can leach into coffee and tea. The measured lead concentrations ranged from 0.2 to 8.6 μg/L in coffee, and from <0.2 to 1.6 μg/L in tea. No statistical differences were found between the measured concentrations in coffee, tea, or water within each cup, or in the measured concentrations between retention times within each cup. However, a statistically significant difference was observed in the lead concentrations measured between cups, indicating that the lead concentrations were dependent on the cup used, rather than on the beverage or retention time. The estimated daily dose of lead exceeded the California Maximum Allowable Dose Level of 0.5 μg per day for one of the five mugs tested. Blood lead levels did not increase above regulatory or guidance values.ConclusionsThis preliminary investigation provides data on potential lead exposures from daily beverage consumption among typical consumers, relevant to a substantial portion of the population, with particular implications for pregnant women.

Biosurveillance De La Qualite De L’air D’un Milieu Urbain Par Des Mousses Et Des Lichens. Cas De La Ville De Tlemcen (Algerie)

The evaluation of the pollution intensity, the accumulation of pollutants in the atmosphere, by living organisms is a very effective environmental technique used for decades. The measure of the accumulation in these organisms allows meeting the direct difficulties in physical and chemical measures, often very complex and costly. By physiological and morphological characteristics, mosses and lichens are very effective to address this issue, including their capacity to accumulate contaminants in this case the trace metals such as lead. The objective of this work is to measure lead concentrations from road origin in different urban sites in Tlemcen city (Algeria) using two species of moss and lichen. The results show high concentrations of lead in the thalles for the three species, indicating high pollution by lead in this city. In order to appreciate the spatial distribution leaving this pollution and its environmental impact in urban areas, it was developed pollution maps based on the results of each species.

Akumulasi Timah Hitam dalam Daging dan Tulang Ayam Kampung dan Ayam Negeri

Lead is a heavy metal polluting the environment, and its accumulation in animal or human bodies canhave neurotoxic and nephrotoxic effects on animals and human. Lead-contaminated chicken meat can bethe source of lead to human. Lead exposure to human can be assessed by measuring its concentration andaccumulation in chicken body parts and analyzing chicken consumption patterns. This study was conductedto measure lead concentrations in chicken body parts and to estimate lead exposure caused by consumptionof chicken body parts (breast, legs, wings) and tissues (meat, skin, cartilage, spongy bones). Samples wereextracted by using aqua regia digestible method with a mixture of HCl: HNO3 (3:1; v/v) and leadconcentrations were measured by the Atomic Absorption Spectrophotometry (AAS) method. The leadconcentrations in chicken tissues varied from< 0.01 to 1.81?g.g-1dry weight.The average concentrations oflead in chicken tissues were lower than the recommended safety level of lead in chicken meat (1.0?g.g-1),except for the breast cartilage (1.03?g.g-1). The lowet accumulation level 2.6 ?g g-1 was found in domesticchicken wings while the highest of 32.9 ?g g-1 was found in broiler chicken breast (total of meat, skin,cartilage). Based on the data of lead accumulation in chicken tissues, a polynomial equation describing theprobability (P) to be exposed to certain amount of lead in chicken tissues (A, in ?g) was determined as P =-(1 x 10-3)A2 + (6,4 x 10-2)A.

Prenatal lead exposure is associated with decreased cord blood DNA methylation of the glycoprotein VI gene involved in platelet activation and thrombus formation.

Early-life lead exposure impairs neurodevelopment and later exposure affects the cardiovascular system. Lead has been associated with reduced global 5-methylcytosine DNA methylation, suggesting that lead toxicity acts through epigenetic mechanisms. The objective of this study is to clarify how early-life lead exposure alters DNA methylation of specific genes, using an epigenomic approach. We measured lead concentrations in urine [gestational week (GW), 8] and erythrocytes (GW 14), using inductively coupled plasma mass spectrometry, for 127 pregnant mothers recruited in the MINIMat food and supplementation cohort in rural Bangladesh. Cord blood DNA methylation was analyzed with the Infinium HumanMethylation450K BeadChip, and top sites were validated by methylation-sensitive high-resolution melt curve analysis. Maternal urinary lead concentrations (divided into quartiles) showed significant (after adjustment for false discovery rate) inverse associations with methylation at nine CpGs. Three of these sites were in the 5′-end, including the promoter, of glycoprotein IV (GP6); cg18355337 (q = 0.029, β = −0.30), cg25818583 (q = 0.041, β = −0.18), and cg23796967 (q = 0.047, β = −0.17). The methylation in another CpG site in GP6 was close to significant (cg05374025, q = 0.057, β = − 0.23). The erythrocyte lead concentrations (divided into quartiles) were also inversely associated with CpG methylation in GP6, although this was not statistically significant after false discovery rate adjustments. Eight CpG sites in GP6 constituted a differentially methylated region in relation to urinary lead (P = 0.005, q = 0.48) and erythrocyte lead (P = 0.007, q = 0.46). In conclusion, we found that moderate prenatal lead exposure appears to epigenetically affect GP6, a key component of platelet aggregation and thrombus formation, suggesting a novel link between early lead exposure and cardiovascular disease later in life.

Environmental determinants of different blood lead levels in children: A quantile analysis from a nationwide survey

Blood lead levels (BLLs) have substantially decreased in recent decades in children in France. However, further reducing exposure is a public health goal because there is no clear toxicological threshold. The identification of the environmental determinants of BLLs as well as risk factors associated with high BLLs is important to update prevention strategies. We aimed to estimate the contribution of environmental sources of lead to different BLLs in children in France.We enrolled 484 children aged from 6months to 6years, in a nationwide cross-sectional survey in 2008–2009. We measured lead concentrations in blood and environmental samples (water, soils, household settled dusts, paints, cosmetics and traditional cookware). We performed two models: a multivariate generalized additive model on the geometric mean (GM), and a quantile regression model on the 10th, 25th, 50th, 75th and 90th quantile of BLLs.The GM of BLLs was 13.8μg/L (=1.38μg/dL) (95% confidence intervals (CI): 12.7–14.9) and the 90th quantile was 25.7μg/L (CI: 24.2–29.5). Household and common area dust, tap water, interior paint, ceramic cookware, traditional cosmetics, playground soil and dust, and environmental tobacco smoke were associated with the GM of BLLs. Household dust and tap water made the largest contributions to both the GM and the 90th quantile of BLLs. The concentration of lead in dust was positively correlated with all quantiles of BLLs even at low concentrations. Lead concentrations in tap water above 5μg/L were also positively correlated with the GM, 75th and 90th quantiles of BLLs in children drinking tap water.Preventative actions must target household settled dust and tap water to reduce the BLLs of children in France. The use of traditional cosmetics should be avoided whereas ceramic cookware should be limited to decorative purposes.