A rationale for lowering the blood lead action level from 10 to 2 microg/dL

Do lead (Pb) content of lipsticks expose a health risk to children? A risk assessment study

BACKGROUND

Lead (Pb) content in lipsticks and potential life-long exposure of which might cause severe effects in consumers are an important concern for public. Thus, studies emphasize that lead exposure has no safe levels.

METHODS

From 10 different brands, in total, 25 solid, gloss and creamy lipsticks are deployed from Turkish markets that are also categorized in two different price ranges. In order to evaluate the blood Pb levels in children, the United States Environmental Protection Agency's 'Exposure Uptake Biokinetic Model' is utilized. To assess the health risk of chronic usage both for children and adults, oral daily systemic exposure levels are calculated with the worst-case scenario and are compared with Maximum Allowable Dose Level for lipsticks. For lifetime risk assessment, exposure is assumed to start by age 7, and four different exposure scenarios have been deployed.

RESULTS

The mean lead content of lipsticks shows significant statistical differences between the high- and low-priced lipstick groups. Daily level and total risk for lifetime Pb exposure from deployed lipsticks are below the acceptable risk levels but long-worn usage of products with routine monitoring of metal content is crucial for sensitive and unintended exposure groups.

Progesterone for Neurodevelopment in Fetuses With Congenital Heart Defects: A Randomized Clinical Trial

Importance

Neurodevelopmental outcomes for children with congenital heart defects (CHD) have improved minimally over the past 20 years.

Objectives

To assess the feasibility and tolerability of maternal progesterone therapy as well as the magnitude of the effect on neurodevelopment for fetuses with CHD.

Design, Setting, and Participants

This double-blinded individually randomized parallel-group clinical trial of vaginal natural progesterone therapy vs placebo in participants carrying fetuses with CHD was conducted between July 2014 and November 2021 at a quaternary care children's hospital. Participants included maternal-fetal dyads where the fetus had CHD identified before 28 weeks' gestational age and was likely to need surgery with cardiopulmonary bypass in the neonatal period. Exclusion criteria included a major genetic or extracardiac anomaly other than 22q11 deletion syndrome and known contraindication to progesterone. Statistical analysis was performed June 2022 to April 2024.

Intervention

Participants were 1:1 block-randomized to vaginal progesterone or placebo by diagnosis: hypoplastic left heart syndrome (HLHS), transposition of the great arteries (TGA), and other CHD diagnoses. Treatment was administered twice daily between 28 and up to 39 weeks' gestational age.

Main Outcomes and Measures

The primary outcome was the motor score of the Bayley Scales of Infant and Toddler Development-III; secondary outcomes included language and cognitive scales. Exploratory prespecified subgroups included cardiac diagnosis, fetal sex, genetic profile, and maternal fetal environment.

Results

The 102 enrolled fetuses primarily had HLHS (n = 52 [50.9%]) and TGA (n = 38 [37.3%]), were more frequently male (n = 67 [65.7%]), and without genetic anomalies (n = 61 [59.8%]). The mean motor score differed by 2.5 units (90% CI, -1.9 to 6.9 units; P = .34) for progesterone compared with placebo, a value not statistically different from 0. Exploratory subgroup analyses suggested treatment heterogeneity for the motor score for cardiac diagnosis (P for interaction = .03) and fetal sex (P for interaction = .04), but not genetic profile (P for interaction = .16) or maternal-fetal environment (P for interaction = .70).

Conclusions and Relevance

In this randomized clinical trial of maternal progesterone therapy, the overall effect was not statistically different from 0. Subgroup analyses suggest heterogeneity of the response to progesterone among CHD diagnosis and fetal sex.

Trial Registration

ClinicalTrials.gov Identifier: NCT02133573.

Neighborhood-scale lead (Pb) speciation in Akron, Ohio (USA) soils: primary sources, post-deposition diagenesis, and high concentrations of labile Pb

Lead (Pb) poses a significant risk to infants and children through exposure to contaminated soil and dust. However, there is a lack of information on Pb speciation and distribution at the neighborhood-scale. This work aimed to determine: (1) the distribution of acid-extractable (labile) Pb and other metals ([M]AE) in two neighborhoods in Akron, Ohio (USA) (Summit Lake and West Akron; n = 82 samples); and (2) Pb speciation and potential sources. Total metal concentration ([M]T) and [M]AE was strongly correlated for Pb and Zn (R2 of 0.66 and 0.55, respectively), corresponding to 35% and 33% acid-extractability. Lead and Zn exhibited a strong positive correlation with each other (R2 = 0.56 for MT and 0.68 for MAE). Three types of Pb-bearing phases were observed by electron microscopy: (1) galena (PbS)-like (5-10 μm); (2) paint chip residuals (10-20 μm); and (3) Pb-bearing Fe-oxides (20 μm). Isotope ratio values for PbAE were 1.159 to 1.245 for 206Pb/207Pb, and 1.999 to 2.098 for 208Pb/206Pb, and there was a statistically significant difference between the two neighborhoods (p = 0.010 for 206Pb/207Pb and p = 0.009 for 208Pb/206Pb). Paint and petrol are the dominant sources of Pb, with some from coal and fly ash. Lead speciation and distribution is variable and reflects a complex relationship between the input of primary sources and post-deposition transformations. This work highlights the importance of community science collaborations to expand the reach of soil sampling and establish areas most at risk based on neighborhood-dependent Pb speciation and distribution for targeted remediation.

Metal mixtures and oral health among children and adolescents in the National Health and Nutrition Examination Survey (NHANES), 2017-2020

INTRODUCTION

Dental caries is the most common non-communicable human disease, yet little is known about the role of environmental metals, despite teeth consisting of a hard matrix of trace elements. We conducted a cross-sectional study of associations between environmental metals and objective assessment of dental caries and subjective assessments of oral health among a representative sample of U.S. children and adolescents.

METHODS

Data were from the 2017-March 2020 pre-pandemic data file of the National Health and Nutrition Examination Survey (NHANES). To account for metal mixtures, we used weighted quantile sum (WQS) regression to estimate the joint impact of multiple trace elements assessed in blood and urine with oral disease outcomes.

RESULTS

The blood metal mixture index was associated with a 32% (95% CI: 1.11, 1.56) increased risk of decayed surfaces while the urine metal mixture index was associated with a 106%, RR (95% CI = 2.06 (1.58, 2.70) increased caries risk. For both blood and urine, Mercury (Hg) had the largest contribution to the mixture index followed by Lead (Pb). The WQS blood metal mixture index was also significantly associated with poorer self-rated oral health, although the magnitude of the association was not as strong as for the objective oral disease measures, RR (95% CI) = 1.04 (1.02, 1.07).

DISCUSSION

Increased exposure to a metal mixture was significantly related to poorer objective and subjective oral health outcomes among U.S. children and adolescents. These are among the first findings showing that metal mixtures are a significant contributor to poor oral health.

Cerqueira F, Menezes-Filho JA. A Cross-Sectional Analysis Investigating Pregnant Women's Renal Function and Its Association with Lead and Cadmium Exposures-The DSAN Birth Cohort Study in Recôncavo Baiano, Brazil

Kidney dysfunction is increasing worldwide and is exacerbated by exposure to toxic metals. Also, pregnancy poses an overload on kidney function. We investigated how blood lead (PbB) and cadmium (CdB) levels were associated with kidney function in pregnant women from Recôncavo Baiano, Brazil, during their second trimester. In this cross-sectional study, the estimated glomerular filtration rate (eGFR) was calculated from serum creatinine and whole blood metal levels were measured by graphite furnace atomic absorption spectrophotometry in 136 volunteers. Sociodemographic data were collected using semi-structured questionnaires. The medians (IQR) of PbB, CdB, and eGFR were 0.85 µg/dL (0.45-1.75), 0.55 µg/L (0.08-0.91), and 121.8 mL/min/1.73 m2 (106.0-127.9), respectively. PbB medians were significantly higher in the eGFR < 90 group at 2.00 µg/dL (0.83, 3.10). After age-adjusted logistic regression, pregnant women with elevated PbB levels had decreased eGFR (OR = 1.82; 95%-CI, 1.14-3.14). However, the participants with elevated PbB levels who reported consuming alcohol during pregnancy or had CdB in the highest tertile had higher odds of reduced eGFR (OR = 2.44; 95%-CI, 1.30-5.47) and (OR = 11.22; 95% CI, 2.53-103.51), respectively. These results suggest that low Pb exposure may affect kidney function in pregnant women and calls for further investigation into toxic metal co-exposures on kidney function during pregnancy in at-risk communities.

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

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

A systematic review of heavy metals contamination in cosmetics

Background: Globally, the consumption and use of cosmetics have increased exponentially. The presence of hazardous metals raises worries about their potential long-term impacts on human health. Objective: This review's primary goal is to shed light on the presence and ranges of heavy metal concentrations in diverse cosmetic samples as well as the instrumental techniques used by various authors to analyse the hazardous metals in the articles under evaluation. Methodology: This analysis concentrated on 16 publications that measured the levels of heavy metals like lead, cadmium, iron, nickel, chromium, and mercury in various cosmetic samples that were published between the years 2012 and 2020. Results: The study's findings support the existence of these metals as pollutants or components in cosmetics, both of which pose substantial health hazards. The regulations and acceptable limits vary across different countries, which is a significant challenge for the cosmetic industry. Conclusion: Therefore, there is a pressing need to standardise the acceptable limits of these toxic metals in cosmetics. Instrumental techniques such as AAS, GFAAS, ICP-OES/ICP-AES, and ICP-MS were employed by Researchers to analyse the toxic metals in cosmetics.

Secular trends in blood lead concentrations of school-age children in Montevideo, Uruguay from 2009 to 2019

Lead exposure continues to be a public health problem globally, yet very few countries perform systematic biomonitoring or surveillance of children's blood lead levels (BLLs). Secular trends in children's BLLs have not been well characterized outside North America and Europe. In 2009-19, we conducted a series of non-representative cross-sectional surveys in Montevideo, Uruguay, enrolling children living in areas of the city with known or suspected lead contamination. Lead was measured with atomic absorption spectrometry on fasting venous blood samples. Of the 856 children representing independent (non-sibling) observations, 759 had BLL measures. Other missing data were imputed. Using linear and logistic regression models, we estimated the covariate-adjusted year to year difference in mean BLL and the likelihood of having BLL ≥5 and BLL ≥3.5 μg/dL. At the start of the study, mean ± SD BLL was 4.8 ± 2.6 μg/dL, and at the end 1.4 ± 1.4 μg/dL. The prevalence of BLL ≥5 and BLL ≥3.5 μg/dL also differed markedly between 2009 and 2019 (30.8% vs. 2.7% and 53.8% vs. 5.8%). Similarly, where 80.8% of children had BLL ≥2 μg/dL in 2011, in 2019 that number was 19.3%. The estimated year to year difference in BLL was ∼0.3 μg/dL. Despite this progress, pediatric lead exposure remains a problem in Montevideo. In years 2015-19, between 19 and 48% of school children had BLL ≥2 μg/dL, a level at which adverse neurobehavioral outcomes continue to be reported in the literature. Continued prevention and risk-reduction efforts are needed in Montevideo, including systematic surveillance of BLLs in all children.

Pb2+-Selective Nanoemulsion-Integrated Single-Entity Electrochemistry for Ultrasensitive Sensing of Blood Lead

Unequivocally, Pb2+ as a harmful substance damaging children's brain and nerve systems, thereby causing behavior and learning disabilities, should be detected much lower than the elevated blood lead for children, 240 nM, endorsed by US CDC considering the unknown neurotoxic effects, yet the ultralow detection limit up to sub-ppb level remains a challenge due to the intrinsically insufficient sensitivity in the current analytical techniques. Here, we present nanoemulsion (NE)-integrated single-entity electrochemistry (NI-SEE) toward ultrasensitive sensing of blood lead using Pb-ion-selective ionophores inside a NE, i.e., Pb2+-selective NE. Through the high thermodynamic selectivity between Pb2+ and Pb-ionophore IV, and the extremely large partition coefficient for the Pb2+-Pb-ionophore complex inside NEs, we modulate the selectivity and sensitivity of NI-SEE for Pb2+ sensing up to an unprecedentedly low detection limit, 20 ppt in aqueous solutions, and lower limit of quantitation, 40 ppb in blood serums. This observation is supported by molecular dynamics simulations, which clearly corroborate intermolecular interactions, e.g., H-bonding and π*-n, between the aromatic rings of Pb-ionophore and lone pair electrons of oxygen in dioctyl sebacate (DOS), plasticizers of NEs, subsequently enhancing the current intensity in NI-SEE. Moreover, the highly sensitive sensing of Pb2+ is enabled by the appropriate suppression of hydroxyl radical formation during NI-SEE under a cathodic potential applied to a Pt electrode. Overall, the experimentally demonstrated NI-SEE approach and the results position our new sensing technology as potential sensors for practical environmental and biomedical applications as well as a platform to interrogate the stoichiometry of target ion-ionophore recognition inside a NE as nanoreactors.

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

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

Screening and Identification of Probiotic Lactobacilli from the Infant Gut Microbiota to Alleviate Lead Toxicity

Lead (Pb2+) exposure cause a potential hazard to human health and the ecological environment; however, prevention and treatment of Pb2+ toxicity remain problems. The aim of this study is to isolate a novel probiotic lead (Pb2+)-resistant Lactobacillus strain from the infant gut microbiota and to determine whether they have the probiotic properties and investigate its preventive and therapeutic effects in the early-life Pb2+ exposure mouse model. In the present study, a total of 64 Pb2+-resistant colonies were isolated from the infant gut microbiota. Of these colonies, SYF-08, identified as Lacticaseibacillus casei, exhibited a Pb2+-binding capacity and Pb2+ tolerance. The in vivo study showed that SYF-08 treatment could effectively reduce Pb2+ levels in the blood, alleviate Pb2+ enrichment in bone and brain tissues, and recover the intestinal and brain damage in both dams and offspring. SYF-08 treatment also improved the antioxidant index in the liver and kidney tissues, while increasing the diversity of the intestinal microbiota of the offspring. The results of the in vitro and in vivo studies suggest that SYF-08, isolated from infant fecal samples, is a promising candidate probiotic against Pb2+ toxicity.

Soluble dietary fiber from Prunus persica dregs alleviates gut microbiota dysfunction through lead excretion

Lead (Pb) can pollute the environment and food through air, water and other means, resulting in human exposure to lead pollution, and there is no threshold level of lead toxicity, even small doses of lead will have a range of harmful effects in humans. This study demonstrates for the first time that dietary addition of soluble dietary fiber (SDF) from Prunus persica dregs reduces lead bioaccumulation in mice, and eliminates lead through feces. Compared with lead-exposed mice, SDF supplementation effectively prevented lead-induced changes in colon tissue, and increased expression of tight junction proteins (ZO-1 and occludin). We analyzed the effects of SDF on gut microbiota and metabolites by a combination of 16S rRNA high-throughput sequencing and untargeted metabolomics. The results showed that SDF altered lead-induced perturbations in the layout and structure of the gut microbiota, including increased Desulfovibrio and Alistipes abundance and decreased Bacteroidetes abundance. Meanwhile, we also provide evidence that SDF supplementation alters the levels of amino acids, bile acids, and lipids in the gut, and that these metabolites are closely associated with microbiota with good lead binding capacity. Therefore, we speculate that SDF has the potential to provide a protective effect against intestinal damage by promoting lead excretion.

Predicting Low-Level Childhood Lead Exposure in Metro Atlanta Using Ensemble Machine Learning of High-Resolution Raster Cells

Low-level lead exposure in children is a major public health issue. Higher-resolution spatial targeting would significantly improve county and state-wide policies and programs for lead exposure prevention that generally intervene across large geographic areas. We use stack-ensemble machine learning, including an elastic net generalized linear model, gradient-boosted machine, and deep neural network, to predict the number of children with venous blood lead levels (BLLs) ≥2 to <5 µg/dL and ≥5 µg/dL in ~1 km2 raster cells in the metro Atlanta region using a sample of 92,792 children ≤5 years old screened between 2010 and 2018. Permutation-based predictor importance and partial dependence plots were used for interpretation. Maps of predicted vs. observed values were generated to compare model performance. According to the EPA Toxic Release Inventory for air-based toxic release facility density, the percentage of the population below the poverty threshold, crime, and road network density was positively associated with the number of children with low-level lead exposure, whereas the percentage of the white population was inversely associated. While predictions generally matched observed values, cells with high counts of lead exposure were underestimated. High-resolution geographic prediction of lead-exposed children using ensemble machine learning is a promising approach to enhance lead prevention efforts.

Improving Equitability and Inclusion for Testing and Detection of Lead Poisoning in US Children

Policy Points Child lead poisoning is associated with socioeconomic inequity and perpetuates health inequality. Methods for testing and detection of child lead poisoning are ill suited to the current demographics and characteristics of the problem. A three-pronged revision of current testing approaches is suggested. Employing the suggested revisions can immediately increase our national capacity for equitable, inclusive testing and detection. ABSTRACT: Child lead poisoning, the longest-standing child public health epidemic in US history, is associated with socioeconomic inequity and perpetuates health inequality. Removing lead from children's environments ("primary prevention") is and must remain the definitive solution for ending child lead poisoning. Until that goal can be realized, protecting children's health necessarily depends on the adequacy of our methods for testing and detection. Current methods for testing and detection, however, are no longer suited to the demographics and magnitude of the problem. We discuss the potential deployment and feasibility of a three-pronged revision of current practices including: 1) acceptance of capillary samples for final determination of lead poisoning, with electronic documentation of "clean" collection methods submitted by workers who complete simple Centers for Disease Control and Prevention-endorsed online training and certification for capillary sample collection; 2) new guidance specifying the analysis of capillary samples by inductively coupled plasma mass spectrometry or graphite furnace atomic absorption spectrometry with documented limit of detection ≤0.2 μg/dL; and 3) adaptive "census tract-specific" universal testing and monitoring guidance for children from birth to 10 years of age. These testing modifications can bring child blood lead level (BLL) testing into homes and communities, immediately increasing our national capacity for inclusive and equitable detection and monitoring of dangerous lower-range BLLs in US children.

A national survey of lead and other metal(loids) in residential drinking water in the United States

BACKGROUND

Exposure to lead (Pb), arsenic (As) and copper (Cu) may cause significant health issues including harmful neurological effects, cancer or organ damage. Determination of human exposure-relevant concentrations of these metal(loids) in drinking water, therefore, is critical.

OBJECTIVE

We sought to characterize exposure-relevant Pb, As, and Cu concentrations in drinking water collected from homes participating in the American Healthy Homes Survey II, a national survey that monitors the prevalence of Pb and related hazards in United States homes.

METHODS

Drinking water samples were collected from a national survey of 678 U.S. homes where children may live using an exposure-based composite sampling protocol. Relationships between metal(loid) concentration, water source and house age were evaluated.

RESULTS

18 of 678 (2.6%) of samples analyzed exceeded 5 µg Pb L-1 (Mean = 1.0 µg L-1). 1.5% of samples exceeded 10 µg As L-1 (Mean = 1.7 µg L-1) and 1,300 µg Cu L-1 (Mean = 125 µg L-1). Private well samples were more likely to exceed metal(loid) concentration thresholds than public water samples. Pb concentrations were correlated with Cu and Zn, indicative of brass as a common Pb source is samples analyzed.

SIGNIFICANCE

Results represent the largest national-scale effort to date to inform exposure risks to Pb, As, and Cu in drinking water in U.S. homes using an exposure-based composite sampling approach.

IMPACT STATEMENT

To date, there are no national-level estimates of Pb, As and Cu in US drinking water collected from household taps using an exposure-based sampling protocol. Therefore, assessing public health impacts from metal(loids) in drinking water remains challenging. Results presented in this study represent the largest effort to date to test for exposure-relevant concentrations of Pb, As and Cu in US household drinking water, providing a critical step toward improved understanding of metal(loid) exposure risk.

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

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

Determinants of Exposure to Potentially Toxic Metals in Pregnant Women of the DSAN-12M Cohort in the Recôncavo Baiano, Brazil

Exposure to potentially toxic metals (PTM) threatens maternal and child health. We investigated the determinants of exposure to lead (Pb), cadmium (Cd), arsenic (As), and manganese (Mn) in 163 pregnant women from the Recôncavo Baiano, Brazil, enrolled in the DSAN-12M cohort. We measured these metals in biological samples (blood, toenails, and hair) and the Pb dust loading rates (RtPb) at their homes by graphite furnace atomic absorption spectrophotometry (GFAAS). Questionnaires were applied to collect sociodemographic and general habits data. Only 2.91% (n = 4) of the pregnant women had As levels above the detection limit. Few participants had levels above the recommended reference values for blood Pb (5.1; 95% CI: 2.1-10.1%), and Mn in hair or toenails (4.3; 95% CI: 2.3-10.1%). On the other hand, 61.1 (95% CI: 52.4-69.3%) had elevated blood Cd levels. After binary logistic regression, low socioeconomic status, domestic waste burning, being a passive smoker, multiparity, and renovating the house significantly increased the chances of having high levels of Mn, Pb, and Cd. We detected a worrying situation related to exposure to Cd, showing the urgency of implementing human biomonitoring in the general population, especially in situations of social vulnerability.

Tracking the source of contaminant lead in children's blood

Pb isotope ratios are used for apportioning the sources of Pb in the blood of children (ages 1-6) screened for high blood Pb levels (>5 μg/dL) surrounding urban areas of Kansas City, MO. We compared Pb isotope ratios measured in the child's blood with those of the most likely sources of Pb in that child's home environment. The environmental sources sampled consisted of topsoils, paints, occupational sources (e.g., oil rig workers' uniforms, mechanics' clothes), indoor air filters, dusts, and dietary sources (e.g., spices). Blood lead levels (BLL) ranged from 2.9 to 12.7 μg/dL in children from the five homes participating in this study. Measurements of ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb isotope ratios were made by multi-collector ICP-MS. Comparison of the Pb isotope ratios in home environment samples versus those in the child's blood in each home allowed the identification of possible sources of a child's Pb exposure in three homes. In five homes investigated, children's blood Pb levels were most likely to be derived from dusts inside, and topsoil outside, the homes, or a mixture thereof. In one case, blood Pb was derived from turmeric spice and, in another, the Pb was derived from paint. It is not always possible to directly link high BLLs to the environmental sources collected when Pb isotope ratios of the environmental samples did not overlap with those of the blood.

Impact of Environmental Pollutants on Gut Microbiome and Mental Health via the Gut–Brain Axis

Over the last few years, the microbiome has emerged as a high-priority research area to discover missing links between brain health and gut dysbiosis. Emerging evidence suggests that the commensal gut microbiome is an important regulator of the gut–brain axis and plays a critical role in brain physiology. Engaging microbiome-generated metabolites such as short-chain fatty acids, the immune system, the enteric nervous system, the endocrine system (including the HPA axis), tryptophan metabolism or the vagus nerve plays a crucial role in communication between the gut microbes and the brain. Humans are exposed to a wide range of pollutants in everyday life that impact our intestinal microbiota and manipulate the bidirectional communication between the gut and the brain, resulting in predisposition to psychiatric or neurological disorders. However, the interaction between xenobiotics, microbiota and neurotoxicity has yet to be completely investigated. Although research into the precise processes of the microbiota–gut–brain axis is growing rapidly, comprehending the implications of environmental contaminants remains challenging. In these milieus, we herein discuss how various environmental pollutants such as phthalates, heavy metals, Bisphenol A and particulate matter may alter the intricate microbiota–gut–brain axis thereby impacting our neurological and overall mental health.

A replicable strategy for mapping air pollution's community-level health impacts and catalyzing prevention

BACKGROUND

Air pollution was responsible for an estimated 6.7 million deaths globally in 2019 and 197,000 deaths in the United States. Fossil fuel combustion is the major source.

HYPOTHESIS

Mapping air pollution's health impacts at the community level using publicly available data and open-source software will provide a replicable strategy for catalyzing pollution prevention.

METHODS

Using EPA's Environmental Benefits Mapping and Analysis (BenMAP-CE) software and state data, we quantified the effects of airborne fine particulate matter (PM_2.5) pollution on disease, death and children's cognitive function (IQ Loss) in each city and town in Massachusetts. To develop a first-order estimate of PM_2.5 pollution's impact on child IQ, we derived a concentration-response coefficient through literature review.

FINDINGS

The annual mean PM_2.5 concentration in Massachusetts in 2019 was 6.3 μg/M³, a level below EPA's standard of 12 μg/M³ and above WHO's guideline of 5 μg/M³. In adults, PM_2.5 pollution was responsible for an estimated 2780 (Confidence Interval [CI] 2726 - 2853) deaths: 1677 (CI, 1346 - 1926) from cardiovascular disease, 2185 (CI, 941-3409) from lung cancer, 200 (CI, 66-316) from stroke, and 343 (CI, 222-458) from chronic respiratory disease. In children, PM_2.5 pollution was responsible for 308 (CI, 105-471) low-weight births, 15,386 (CJ, 5433-23,483) asthma cases, and a provisionally estimated loss of nearly 2 million Performance IQ points; IQ loss impairs children's school performance, reduces graduation rates and decreases lifetime earnings. Air-pollution-related disease, death and IQ loss were most severe in low-income, minority communities, but occurred in every city and town in Massachusetts regardless of location, demographics or median family income.

CONCLUSION

Disease, death and IQ loss occur at air pollution exposure levels below current EPA standards. Prevention of disease and premature death and preservation of children's cognitive function will require that EPA air quality standards be tightened. Enduring prevention will require government-incentivized transition to renewable energy coupled with phase-outs of subsidies and tax breaks for fossil fuels. Highly localized information on air pollution's impacts on health and on children's cognitive function has potential to catalyze pollution prevention.

Environmental lead exposure and its correlation with intelligence quotient level in children

BACKGROUND

Lead (Pb) is ubiquitous, naturally occurring heavy metal that has a neurotoxic effect on the CNS and causes a range of health problems in humans, including cognitive impairment. Its toxicity remains a worldwide health issue, especially in developing countries. In this study, we tend to investigate the relationship between Pb poisoning and sociodemographic status, intellectual and neurobehavioral capabilities of children.

METHODS

The background characteristics of the research subjects were collected via questionnaire. The study involved 43 children, aged from 4 to 12 years. Blood lead (BL) levels were analysed by using anodic stripping voltammeter (ASV). Intelligence quotient (IQ) was another parameter that was assessed via using the Goodenough draw-A-person test in Pb exposed as well as control children. Although sociodemographic information was obtained in a questionnaire pattern from the parents.

RESULTS

The mean of BL level was 19.93 ± 9.22 μg/dL. BL levels were considerably higher with low social status (p < 0.05), maternal employment (p < 0.001) and the maximum time spent outdoors (p < 0.001). Source of water, age of subjects, type of house and kohl used by children was observed to be significantly correlated with BL levels i.e. (p < 0.05). IQ levels were decreased in a concentration dependent manner (p < 0.01). Negative correlations were found between BL levels and IQ levels (r = -0.963, <0.01). Girls were found to be higher IQ level than boys (p < 0.05). Moreover, higher socioeconomic status had a higher IQ level (p < 0.01) as compared to low.

CONCLUSION

BL levels were significantly associated with IQ levels. Sociodemographic characteristic was also found to be one of the risk factors that influenced the BL levels of children. Our investigations have demonstrated that the exposure of Pb severely affected the learning with memory, and the intelligence quotient of children, that is found inversely proportional in respect to BL levels.

Trends of Blood Lead Levels in US Pregnant Women: The National Health and Nutrition Examination Survey (2001–2018)

Objectives

This study investigates the trends of blood lead levels in US pregnant women based on the National Health and Nutrition Examination Survey from 2001 to 2018.

Methods

A total of 1,230 pregnant women were included in this study. The weighted logistic regression was applied to analyze the association between sociodemographic characteristics with high blood levels. We computed the blood lead levels for each survey period from 2001–2002 to 2017–2018. Moreover, we used the adjusted linear regression model to investigate the time-related change in blood lead level. The odds ratio (OR) with a 95% confidence interval (CI) was calculated accordingly.

Results

The mean blood lead was 0.73 ± 0.03 ug/dL, and high blood lead was observed in 2.53% of individuals. The Mexican Americans were more associated with high blood lead than the non-Hispanic white (OR, 1.072; 95% CI, 1.032-1.112). The mean blood lead level has decreased from 0.97 ug/dL in 2001–2002 to 0.46 ug/dL in 2013–2014. Afterward, a slight increase was observed with the mean blood lead of 0.55 ug/dL in 2015–2016 and 0.53 ug/dL in 2017-2018. In the adjusted linear regression model, each year's increase would lead to a 0.029 ug/dL decrease in blood lead (P < 0.001). However, no significant change was observed in the 2017–2018 cycle compared with 2009–2010 (P = 0.218).

Conclusion

This study summarized the trend of blood lead levels in US pregnant women over 2001–2018. Continued effort is still required to control lead sources better and protect this population from lead exposure.

Patterns of Children's Blood Lead Screening and Blood Lead Levels in North Carolina, 2011-2018-Who Is Tested, Who Is Missed?

BACKGROUND

No safe level of lead in blood has been identified. Blood lead testing is required for children on Medicaid, but it is at the discretion of providers and parents for others. Elevated blood lead levels (EBLLs) cannot be identified in children who are not tested.

OBJECTIVES

The aims of this research were to identify determinants of lead testing and EBLLs among North Carolina children and estimate the number of additional children with EBLLs among those not tested.

METHODS

We linked geocoded North Carolina birth certificates from 2011-2016 to 2010 U.S. Census data and North Carolina blood lead test results from 2011-2018. We estimated the probability of being screened for lead and created inverse probability (IP) of testing weights. We evaluated the risk of an EBLL of ≥3μg/dL at <30  months of age, conditional on characteristics at birth, using generalized linear models and then applied IP weights to account for missing blood lead results among unscreened children. We estimated the number of additional children with EBLLs of all North Carolina children using the IP-weighted population and bootstrapping to produce 95% credible intervals (CrI).

RESULTS

Mothers of the 63.5% of children (402,002 of 633,159) linked to a blood lead test result were disproportionately young, Hispanic, Black, American Indian, or on Medicaid. In full models, maternal age ≤20y [risk ratio (RR)=1.10; 95% confidence interval (CI): 1.13, 1.20] or smoking (RR=1.14; 95% CI: 1.12, 1.17); proximity to a major roadway (RR=1.10; 95% CI: 1.05, 1.15); proximity to a lead-releasing Toxics Release Inventory site (RR=1.08; 95% CI: 1.03, 1.14) or a National Emissions Inventory site (RR=1.11; 95% CI: 1.07, 1.14); and living in neighborhoods with more housing built before 1950 (RR=1.10; 95% CI: 1.05, 1.14) or before 1940 (RR=1.18; 95% CI: 1.11, 1.25) or more vacant housing (RR=1.14; 95% CI: 1.11, 1.17) were associated with an increased risk of EBLL, whereas overlap with a public water service system was associated with a decreased risk of EBLL (RR=0.85; 95% CI: 0.83, 0.87). Children of Black mothers were no more likely than children of White mothers to have EBLLs (RR=0.98; 95% CI: 0.96, 1.01). Complete blood lead screening in 2011-2018 may have identified an additional 17,543 (95% CrI: 17,462, 17,650) children with EBLLs ≥3μg/dL.

DISCUSSION

Our results indicate that current North Carolina lead screening strategies fail to identify over 30% (17,543 of 57,398) of children with subclinical lead poisoning and that accounting for characteristics at birth alters the conclusions about racial disparities in children's EBLLs. https://doi.org/10.1289/EHP10335.

The effect of lead exposure on IQ test scores in children under 12 years: a systematic review and meta-analysis of case-control studies

An inevitable exposure to the toxic heavy metal such as lead in our environmental can have irreversible effects on children's mental performance.In this study, 3316 children in 8 case-control studies were selected for review. The case group was exposed to a concentration of lead above 10 μg/dL, and the control group was exposed to a concentration of less than 10 μg/dL, but the duration of exposure was different among studies, and the subgroup analysis was performed based on this variable.In the subgroup with duration of exposure less than the average of 4.5 years, the difference of IQ test score between two groups was significant (MD = -3.53) (P-value <0.05). Also, in the subgroup with more than 4.5 years of duration, the difference of IQ test score was significant (MD = -22.63) (P-value < 0.001).This study demonstrates that the concentration and duration of lead exposure have a large effect on mental function in children.

Factors associated with blood lead levels in children in Shenyang, China: a cross-sectional study

Background

Although blood lead levels (BLLs) in children are gradually decreasing, low-concentration lead exposure can still exert adverse effects. We studied the factors that affect BLLs in children in Shenyang, China.

Methods

We conducted a cross-sectional study by administering structured questionnaires on family demographics and food intake. The concentrations of lead in venous blood were determined by graphite furnace atomic absorption spectrometry.

Results

A total of 273 children aged 1–6 years were enrolled. The geometric mean (geometric standard deviation) of BLLs was 24.94 (12.70) μg/L in boys and 23.75 (11.34) μg/L in girls. The prevalence of BLLs of ≥35 μg/L was 22.7% and was mainly observed in children aged under 3 years. Often hand washing before meals was protective against BLLs ≥20 μg/L (adjusted OR: 0.427, 95%CI: 0.238–0.767, p = 0.004). Consumption of puffed grains and eggs had an adjusted OR (95%CI) for BLLs ≥20 μg/L of 1.714 (1.012–2.901) (p = 0.045) and 1.787 (1.000–3.192) (p = 0.050), respectively.

Conclusions

BLLs of children in Shenyang are still higher than in developed countries. Consumption of puffed grains and eggs is associated with higher BLLs. Often hand washing before meals may be protective against high BLLs.

Taurine-Derived Compounds Produce Anxiolytic Effects in Rats Following Developmental Lead Exposure

Lead (Pb2+) is a developmental neurotoxicant that disrupts the GABA-shift and subsequently causes alterations in the brain's excitation-to-inhibition (E/I) balance. Taurine is a well-established neuroprotective and inhibitory compound for regulating brain excitability. Since mechanistically taurine can facilitate neuronal inhibition through the GABA-AR, the present study examined the anxiolytic potential of taurine derivatives. Treatment groups consisted of the following developmental Pb2+-exposures: Control (0 ppm) and Perinatal (150 ppm or 1,000 ppm lead acetate in the drinking water). Rats were scheduled for behavioral tests between postnatal days (PND) 36-45 with random drug assignments to either saline, taurine, or taurine-derived compound (TD-101, TD-102, or TD-103) to assess the rats' responsivity to each drug in mitigating the developmental Pb2+-exposure and anxiety-like behaviors through the GABAergic system. Long-Evans hooded rats were assessed using an open field (OF) test for preliminary locomotor assessment. Twenty-four hours later, the same rats were exposed to the elevated plus maze (EPM) and were given an i.p. injection of 43 mg/Kg of the saline, taurine, or TD drugs 15 min prior to testing. Each rat was tested using the triple-blind random assignment method for each drug condition. The OF data revealed that Control female rats had increased locomotor activity over Control male rats, and the Pb2+-exposed males and females had increased locomotor activity when compared to the Control male and female rats. However, in the EPM, the Control female rats exhibited more anxiety-like behaviors over Control male rats, and the Pb2+-exposed male and female rats showed selective responsivity to TD drugs when compared to taurine. For Pb2+-exposed males, TD-101 showed consistent recovery of anxiety-like behaviors similar to that of taurine regardless of Pb2+ dose, whereas in Pb2+-exposed females TD-101 and TD-103 showed greater anxiolytic responses in the EPM. The results from the present psychopharmacological study suggests that taurine and its derivatives are interesting drug candidates to explore sex-specific mechanisms and actions of taurine and the associated GABAergic receptor properties by which these compounds alleviate anxiety as a potential behavioral pharmacotherapy for neurodevelopmental Pb2+ exposure.

The Safe Urban Harvests Study: A Community-Driven Cross-Sectional Assessment of Metals in Soil, Irrigation Water, and Produce from Urban Farms and Gardens in Baltimore, Maryland

BACKGROUND

Emerging evidence suggests social, health, environmental, and economic benefits of urban agriculture (UA). However, limited work has characterized the risks from metal contaminant exposures faced by urban growers and consumers of urban-grown produce.

OBJECTIVES

We aimed to answer community-driven questions about the safety of UA and the consumption of urban-grown produce by measuring concentrations of nine metals in the soil, irrigation water, and urban-grown produce across urban farms and gardens in Baltimore, Maryland.

METHODS

We measured concentrations of 6 nonessential [arsenic (As), barium (Ba), cadmium (Cd), chromium (Cr), lead (Pb), nickel (Ni)] and three essential [copper (Cu), manganese (Mn), zinc (Zn)] metals in soil, irrigation water, and 13 types of urban-grown produce collected from 104 UA sites. We compared measured concentrations to existing public health guidelines and analyzed relationships between urban soil and produce concentrations. In the absence of guidelines for metals in produce, we compared metals concentrations in urban-grown produce with those in produce purchased from farmers markets and grocery stores (both conventionally grown and U.S. Department of Agriculture-certified organic).

RESULTS

Mean concentrations of all measured metals in irrigation water were below public health guidelines. Mean concentrations of nonessential metals in growing area soils were below public health guidelines for Ba, Cd, Pb, and Ni and at or below background for As and Cr. Though we observed a few statistically significant differences in concentrations between urban and nonurban produce items for some combinations, no consistent or discernable patterns emerged.

DISCUSSION

Screening soils for heavy metals is a critical best practice for urban growers. Given limitations in existing public health guidelines for metals in soil, irrigation water, and produce, additional exposure assessment is necessary to quantify potential human health risks associated with exposure to nonessential metals when engaging in UA and consuming urban-grown produce. Conversely, the potential health benefits of consuming essential metals in urban-grown produce also merit further research. https://doi.org/10.1289/EHP9431.

Lead (Pb) and neurodevelopment: A review on exposure and biomarkers of effect (BDNF, HDL) and susceptibility

Lead (Pb) is a ubiquitous environmental pollutant and a potent toxic compound. Humans are exposed to Pb through inhalation, ingestion, and skin contact via food, water, tobacco smoke, air, dust, and soil. Pb accumulates in bones, brain, liver and kidney. Fetal exposure occurs via transplacental transmission. The most critical health effects are developmental neurotoxicity in infants and cardiovascular effects and nephrotoxicity in adults. Pb exposure has been steadily decreasing over the past decades, but there are few recent exposure data from the general European population; moreover, no safe Pb limit has been set. Sensitive biomarkers of exposure, effect and susceptibility, that reliably and timely indicate Pb-associated toxicity are required to assess human exposure-health relationships in a situation of low to moderate exposure. Therefore, a systematic literature review based on PubMed entries published before July 2019 that addressed Pb exposure and biomarkers of effect and susceptibility, neurodevelopmental toxicity, epigenetic modifications, and transcriptomics was conducted. Finally included were 58 original papers on Pb exposure and 17 studies on biomarkers. The biomarkers that are linked to Pb exposure and neurodevelopment were grouped into effect biomarkers (serum brain-derived neurotrophic factor (BDNF) and serum/saliva cortisol), susceptibility markers (epigenetic markers and gene sequence variants) and other biomarkers (serum high-density lipoprotein (HDL), maternal iron (Fe) and calcium (Ca) status). Serum BDNF and plasma HDL are potential candidates to be further validated as effect markers for routine use in HBM studies of Pb, complemented by markers of Fe and Ca status to also address nutritional interactions related to neurodevelopmental disorders. For several markers, a causal relationship with Pb-induced neurodevelopmental toxicity is likely. Results on BDNF are discussed in relation to Adverse Outcome Pathway (AOP) 13 ("Chronic binding of antagonist to N-methyl-D-aspartate receptors (NMDARs) during brain development induces impairment of learning and memory abilities") of the AOP-Wiki. Further studies are needed to validate sensitive, reliable, and timely effect biomarkers, especially for low to moderate Pb exposure scenarios.

Risk of lead exposure, subcortical brain structure, and cognition in a large cohort of 9- to 10-year-old children

BACKGROUND

Lead, a toxic metal, affects cognitive development at the lowest measurable concentrations found in children, but little is known about its direct impact on brain development. Recently, we reported widespread decreases in cortical surface area and volume with increased risks of lead exposure, primarily in children of low-income families.

METHODS AND FINDINGS

We examined associations of neighborhood-level risk of lead exposure with cognitive test performance and subcortical brain volumes. We also examined whether subcortical structure mediated associations between lead risk and cognitive performance. Our analyses employed a cross-sectional analysis of baseline data from the observational Adolescent Brain Cognitive Development (ABCD) Study. The multi-center ABCD Study used school-based enrollment to recruit a demographically diverse cohort of almost 11,900 9- and 10-year-old children from an initial 22 study sites. The analyzed sample included data from 8,524 typically developing child participants and their parents or caregivers. The primary outcomes and measures were subcortical brain structure, cognitive performance using the National Institutes of Health Toolbox, and geocoded risk of lead exposure. Children who lived in neighborhoods with greater risks of environmental lead exposure exhibited smaller volumes of the mid-anterior (partial correlation coefficient [rp] = -0.040), central (rp = -0.038), and mid-posterior corpus callosum (rp = -0.035). Smaller volumes of these three callosal regions were associated with poorer performance on cognitive tests measuring language and processing speed. The association of lead exposure risk with cognitive performance was partially mediated through callosal volume, particularly the mid-posterior corpus callosum. In contrast, neighborhood-level indicators of disadvantage were not associated with smaller volumes of these brain structures.

CONCLUSIONS

Environmental factors related to the risk of lead exposure may be associated with certain aspects of cognitive functioning via diminished subcortical brain structure, including the anterior splenium (i.e., mid-posterior corpus callosum).

Comprehensive screen the lead and other toxic metals in total environment from a coal-gas industrial city (NW, China): Based on integrated source-specific risks and site-specific blood lead levels of 0-6 aged children

A new integrated source-specific risk model and site-specific blood lead levels (BLLs) of 0-6 children were introduced to comprehensive understand the status of the toxic metals in soil-dust-plant total environment from a Coal-Gas industrial city, NW China. 144 samples were collected and ten toxic metals (As, Ba, Co, Cr, Cu, Mn, Ni, Sr, Pb, and Zn) were screened by XRF and ICP-MS. It was found that the occurrences of toxic metals deferred in the different medium, such as Co, Cu, Pb, and Zn observed the trend of accumulating in soil and plant compared to clustered distributions of Cr, Mn and Ni preferred to accumulate in dust. However, few bioaccumulations observed in Ulmus pumila L. Toxic metals distributions in majority of sites influenced by coal combustion mixed sources and industrial activities posed the high integrated ecological risks and caused significant non-carcinogenic and carcinogenic integrated risks for local 0-6 children identified by new integrated source-specific risk model, especially observed in the priority contaminants Co and Pb. The site-specific BLLs confirmed that younger children fewer than 4 lived in the north region were more vulnerable to priority Pb pollution as their BLLs above 50 μg/L, almost up to 80 μg/L. Although proportions of source-specific risks to toxic metals changed in soil and dust, the critical sources from coal combustions and industrial activities posed the most important contribution to the local risks. Therefore, effective strategies targeting at critical sources on coal industries should be conducted to reduce risks, and mostly emphasize on the north hotspot areas.

Association of prenatal factors and cord blood lead levels in China: A nested cohort cross-sectional study

BACKGROUND

Lead exposure all over the world has gradually declined. As fetuses are more prone to lead exposure, even to low levels of lead exposure, it is important to monitor blood lead levels (BLLs) in pregnancy.

METHODS

We obtained data on BLLs in the third trimester of pregnancy from medical records and measured cord BLLs obtained from 121 mother-child pairs in Shenyang, China from September 2019 to February 2020. We also estimated relationships between socio-demographic, lifestyle and dietary factors during pregnancy as well as cord BLLs to identify the source of lead exposure during pregnancy. BLLs was estimated by atomic absorption spectrometry through graphite furnace ionization techniques. The data which obtained by questionnaires during pregnancy included maternal sociodemographic, lifestyle, dietary factors. We have established three multivariate logistic regression models in which the dichotomous BLLs was used as the dependent variable (cord BLLs ≥20 μg/L vs <20 μg/L).

RESULTS

The median and geometric mean of cord BLLs were 22.90 μg/L, 21.88 μg/L and BLLs in the third trimester of pregnancy were 25.29 μg/L, 24.66 μg/L, respectively. BLLs showed significant correlations between cord and the third trimester of pregnancy (r = 0.277, P = 0.012). Pregnant women who had not been exposed to passive smoking had lower OR (95 %) [0.43(0.19-0.94)] for cord BLLs ≥20 μg/L than pregnant women who had. Intake of docosahexaenoic acid (DHA) during third trimester of pregnancy presented an OR (95 %) [0.23(0.08-0.61)] for cord BLLs ≥20 μg/L. Consuming more whole grains (>3 times/week) and beverage (≥1 times/week) showed an OR (95%CI) for cord BLLs ≥20 μg/L of 0.09(0.02-0.53) and 0.19(0.06-0.69), respectively.

CONCLUSION

This study showed the cord BLLs of Chinese are still higher than most developed countries. Passive smoking is a risk factor for cord BLLs ≥20 μg/L and supplement of DHA, whole grains and beverage consumption during pregnancy may act as a beneficial factor against having cord BLLs ≥20 μg/L.

What is the environment in environmental health research? Perspectives from the ethics of science

Environmental health research produces scientific knowledge about environmental hazards crucial for public health and environmental justice movements that seek to prevent or reduce exposure to these hazards. The environment in environmental health research is conceptualized as the range of possible social, biological, chemical, and/or physical hazards or risks to human health, some of which merit study due to factors such as their probability and severity, the feasibility of their remediation, and injustice in their distribution. This paper explores the ethics of identifying the relevant environment for environmental health research, as judgments involved in defining an environmental hazard or risk, judgments of that hazard or risk's probability, severity, and/or injustice, as well as the feasibility of its remediation, all ought to appeal to non-epistemic as well as epistemic values. I illustrate by discussing the case of environmental lead, a housing-related hazard that remains unjustly distributed by race and class and is particularly dangerous to children. Examining a controversy in environmental health research ethics where researchers tested multiple levels of lead abatement in lead-contaminated households, I argue that the broader perspective on the ethics of environmental health research provided in the first part of this paper may have helped prevent this controversy.

Estimated IQ points and lifetime earnings lost to early childhood blood lead levels in the United States

There is no safe detectable level of lead (Pb) in the blood of children. Blood lead levels (BLLs) at ages 6-24 months ≥2 μg/dL result in lost grade school intelligence quotient (IQ) points at ages 5-10 years. Black children continue to have the highest BLLs in the United States. Therefore, we examined currently undetermined racial/ethnic disparities in anticipated IQ points and associated lifetime earnings lost to early childhood blood lead. We conducted secondary analysis of infants with blood lead (in μg/dL) measured at ages 12-24 months by the cross-sectional National Health and Nutrition Examination Survey (NHANES) during 1999 to 2010. Nationally-representative estimates were produced using weighted simulation model. A total of 1241 infants were included from the NHANES sample (52% male; mean [SD] age, 18.5 [3.5] months; 25% Black [non-Hispanic], 42% Hispanic [any race], 5% Other/Multiracial, and 29% White [non-Hispanic]) after excluding 811 without BLL determinations. For national outcomes, Black infants experienced approximately 46-55% greater average estimated loss of grade school IQ points from blood lead than Hispanic or White infants (-1.78 IQ points vs. -1.15 and -1.21 respectively) with similar disparities in costs to expected lifetime earnings (-$47,116 USD vs. -$30,393 and -$32,356 respectively). Our estimated nationwide costs of IQ points lost to BLLs during this 12-year period totaled $554 billion ($46.2 billion/year), in which blood lead <5 μg/dL accounted for 74% of this total burden. We report two aspects of the substantial national costs attributable to lead exposure in just the second year of life alone, which disproportionately impact predominately African-American Black infants from continuing legacies of environmental racism in lead exposure. Our findings underscore the remarkably high costs from recognized hazards of blood lead even at the lowest levels and the importance of primary prevention regarding childhood lead exposure.

Urban-Soil Pedogenesis Drives Contrasting Legacies of Lead from Paint and Gasoline in City Soil

This study analyzed the impact of urban-soil pedogenesis on soil lead (Pb) contamination from paint and gasoline in the historic core of Durham, North Carolina. Total soil Pb in 1000 samples from streetsides, residential properties, and residual upland and floodplains ranged from 6 to 8825 mg/kg (mean = 211 mg/kg), with 50% of samples between 50 and 200 mg/kg soil Pb. The highest Pb concentrations were within 1 m of pre-1978 residential foundations, with concentrations inversely correlated with house age. Streetside soil Pb concentrations were elevated over the geologic background of <30 mg/kg and correlated with traffic flow. Streetside soil Pb concentrations were lower than Durham streetside soils collected in the 1970s, which was attributed to urban pedogenesis, the complex of natural and human processes that change soils over time. Accelerated erosion redistributes legacy Pb and floodplain sampling indicates sedimentation rates of up to 4 mm/year. Mixing and burial of soil with elevated Pb are also lowering soil Pb concentrations over time. These mechanisms are likely of greater significance on streetsides than near foundation soils. The development of an urban-pedogenesis framework can help guide public health approaches to Pb exposure by incorporating pedogenic processes that reduce and dissipate soil Pb contamination.

Characteristics and Risk Assessment of Soil Polluted by Lead around Various Metal Mines in China

The contamination of soil by lead (Pb) is a serious and widespread problem in China, especially in mining areas. This paper summarized the available data regarding Pb-contaminated soils around various metal mines in China. Based on these data, the Pb concentration in the soil and its temporal and spatial changes were analyzed. Potential ecological hazards and adult lead models were also used to estimate ecological and health risks. The results indicated that the concentration of Pb was closely related with the type of mine. Compared with other types of mine, soil around lead-zinc (Pb-Zn) and tin (Sn) mines with high Pb contents in the metallic ores and high pollutant emission coefficient were more strongly polluted by Pb. The characteristic spatial and temporal variations of Pb pollution status in China were clarified, and the results showed that the concentration was high in the southern, southwestern, and central regions of China where many mining areas were located, and the mean value passed a turning point in 2012. Ecological risk assessments indicated that some areas around mines were at considerable to high risk, and the risk was relatively severe in Pb-Zn mining areas. According to the adult lead model, Pb-Zn mines had a greater impact on blood Pb concentration than the other types of mine.

Pb Toxicity on Gut Physiology and Microbiota

Lead (Pb) is a toxic heavy metal, having profound threats to the global population. Multiple organs such as kidney, and liver, as well as nervous, hematologic, and reproductive systems, are commonly considered the targets of Pb toxicity. Increasing researches reported that the effects of Pb on gastrointestinal tracts are equally intensive, especially on intestinal microbiota. This review summarized Pb toxicity on gut physiology and microbiota in different animal models and in humans, of which the alterations may further have effects on other organs in host. To be more specific, Pb can impair gut barrier and increase gut permeability, which make inflammatory cytokines, immunologic factors, as well as microbial metabolites such as bile acids (BA) and short-chain fatty acids (SCFAs) enter the enterohepatic circulation easily, and finally induce multiple systematic lesion. In addition, we emphasized that probiotic treatment may be one of the feasible and effective strategies for preventing Pb toxicity.

Blood Lead Level in a Paediatric Population of South-Eastern Spain and Associated Risk Factors

Objective: To determine blood lead levels (BLL) in a healthy paediatric population and to analyse related sociodemographic, dietary and haematological factors. Methods: A cross-sectional study was made of 1427 healthy subjects aged 1–16 years from the city of Almería (south-eastern Spain). BLL, iron parameters and erythropoietin were determined, and sociodemographic and dietary data obtained. The study paramateters was analyses in BLL toxic and BLL no toxic group by multiple logistic regression. Results: The mean BLL was 1.98 ± 1.1 µg/dL (95% CI:1.91–2.04). For 5.7% of the population, mean BLL was 2–5 µg/dL, for 2.1% it was >5 µg/dL and for 0.15% it was >10 µg/dL. Multivariate analysis showed that immigrant origin (OR:11.9; p < 0.0001), low level of parental education (OR:4.6; p < 0.02) and low dietary iron bioavailability (OR: 3.2; p < 0.02) were all risk factors for toxic BLL. Subjects with toxic and non-toxic BLL presented similar iron and erythropoiesis-related parameters, except erythrocyte protoporphyrin, which was significantly higher in the BLL >5 µg/dL group. Conclusions: BLL and the prevalence of toxic BLL in healthy subjects aged 1–16 years living in south-eastern Spain are low and similar to those found in other developed countries. The factors associated with toxic BLL are immigrant origin, low level of parental education and dietary iron deficiency. The toxicity of BLL was not related to changes in the analytical parameters studied.

Retrospective blood lead assessment from archived clotted erythrocyte fraction in a cohort of lead-exposed mother-child dyads

Exposure to lead (Pb) is linked to a host of adverse health effects. Recent revelations of unmonitored exposures to hazardous levels of lead as seen in the Flint Water Crisis have manifested a need for evaluating biological samples, other than regularly prepared whole blood, for biomonitoring of lead exposure. Here, we present a method utilizing clotted erythrocyte fraction samples, which are commonly archived along with serum (or plasma) in biorepositories, to predict whole blood lead levels to allow for retrospective assessments of environmental exposure to lead. Whole blood and clotted erythrocyte fraction samples were collected from 91 participants in the Airborne Exposure to Semivolatile Organic Pollutants (AESOP) cohort study of mother-child dyads. Clotted erythrocyte fraction samples were prepared either using microwave assisted acid digestion or alkaline dilution and subsequently analyzed for lead using Inductively-couple plasma-mass spectrometry (ICP-MS). Simultaneously withdrawn whole blood samples were also analyzed. A strong linear relationship was observed between lead in whole blood and clotted erythrocyte fraction with Pearson correlation coefficients (r) of 0.90, and 0.89 (p < 0.001) for acid digestion and alkaline dilution, respectively. Slopes and intercepts from simple linear regression models of the two clotted erythrocyte fraction methods were not found to be significantly different (p > 0.05) when compared to the standard blood lead assay method. Modeled blood lead predicted from clotted erythrocyte fraction was evaluated at a test threshold of 3 μg/dL was found to have diagnostic sensitivity of 88% and specificity of 100%. Results from this study demonstrate clotted erythrocyte fraction samples are a viable alternative biological sample for retrospective public health surveillance of environmental exposure to lead.

Prenatal and postnatal lead exposures and intellectual development among 12-year-old Japanese children

BACKGROUND

Low-level lead exposure during childhood is associated with deficit in child IQ. However, the association between prenatal lead exposure and child IQ remains inconsistent. The objective of our study was to examine the association between prenatal/postnatal lead exposure and child IQ at the age of 12.

METHODS

We obtained data pertaining to cord-blood and child-blood lead levels and IQ for 286 children from a prospective birth cohort study (Tohoku Study of Child Development). IQ was assessed using the Wechsler Intelligence Scale for Children-Fourth Edition. Simultaneously, the Boston Naming Test (BNT) was used to assess the children's language ability.

RESULTS

The median lead level in the cord blood was 0.8 μg/dL (5th-95th percentiles, 0.4-1.4 μg/dL), and that in the blood of 12-year-old children was 0.7 μg/dL (0.4-1.1 μg/dL). IQ and BNT scores were significantly lower in boys than in girls; therefore, multiple regression analysis was conducted separately for boys and girls. Among boys, IQ was associated with child-blood lead (B = -16.362, p = 0.033) but not cord-blood lead (B = -6.844, p = 0.309). When boys were divided into four groups according to the child-blood lead levels, there was a significant decreasing trend for IQ. The score with cues of the BNT was associated with both cord-blood (B = -5.893, p = 0.025) and child-blood (B = -7.108, p = 0.022) lead concentrations in boys. Among girls, there was no significant association of the outcomes with cord-blood or child-blood lead level.

CONCLUSIONS

These findings suggest that postnatal lead exposure adversely affects the intellectual ability in boys. Furthermore, the language ability is sensitive to prenatal/postnatal lead exposure in boys.

Autism spectrum disorder at the crossroad between genes and environment: contributions, convergences, and interactions in ASD developmental pathophysiology

The complex pathophysiology of autism spectrum disorder encompasses interactions between genetic and environmental factors. On the one hand, hundreds of genes, converging at the functional level on selective biological domains such as epigenetic regulation and synaptic function, have been identified to be either causative or risk factors of autism. On the other hand, exposure to chemicals that are widespread in the environment, such as endocrine disruptors, has been associated with adverse effects on human health, including neurodevelopmental disorders. Interestingly, experimental results suggest an overlap in the regulatory pathways perturbed by genetic mutations and environmental factors, depicting convergences and complex interplays between genetic susceptibility and toxic insults. The pervasive nature of chemical exposure poses pivotal challenges for neurotoxicological studies, regulatory agencies, and policy makers. This highlights an emerging need of developing new integrative models, including biomonitoring, epidemiology, experimental, and computational tools, able to capture real-life scenarios encompassing the interaction between chronic exposure to mixture of substances and individuals' genetic backgrounds. In this review, we address the intertwined roles of genetic lesions and environmental insults. Specifically, we outline the transformative potential of stem cell models, coupled with omics analytical approaches at increasingly single cell resolution, as converging tools to experimentally dissect the pathogenic mechanisms underlying neurodevelopmental disorders, as well as to improve developmental neurotoxicology risk assessment.

Blood levels of lead and dental caries in permanent teeth

OBJECTIVES

The purpose of this study was to determine whether there is an association between lead exposure within the ages of 1-4 years and dental caries in the permanent dentition between ages 9-17 among Mexican youth.

METHODS

Data were collected for the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort from a group of 490 children born and reared in Mexico City. Among ages 1-4 years, blood lead levels were measured in micrograms of lead per deciliter of blood (μg/dL) and the presence of caries in adolescence was determined using the International Caries and Detection and Assessment System (ICDAS). The relationship between blood levels of lead and decayed, missing, or filled surfaces (DMFS) was examined using negative binomial regression. Covariates were selected based on previous studies and included age, gender, socioeconomic status, oral hygiene, body mass index, and diet. The nonlinear relationship between lead and DMFS was examined using smoothing splines.

RESULTS

The mean overall blood lead level (BLL) was 4.83 μg/dL (S.D. of 2.2). The mean overall caries level (DMFS) was 4.1. No statistically significant association was found between early childhood blood lead levels and dental caries in adolescence.

CONCLUSION

This study shows a lack of association between exposure to lead between the ages of 1-4 years of age and dental caries in permanent dentition later in life. Other covariates, such as age and sugar consumption, appeared to play a more prominent role in caries development.

Comparative Evaluation of Heavy Metal Concentrations in Residents of Abandoned Metal Mines

This study compares the heavy metal exposure levels of the population of abandoned metal mines, with high risks of environmental pollution and health effects. We used data from a two-stage abandoned metal mines survey (AMS, n = 4467). The Korea National Health and Nutrition Examination Survey (KNHANES) and the Korea National Environmental Health Survey (KNEHS) were used as general population data. Based on the sex and age distribution in the AMS, a simple random sampling was performed, so that the two datasets had the same distribution (KNHANES n = 1815, KNEHS n = 2328). Blood lead concentrations were slightly higher in the AMS than in KNEHS. Blood cadmium concentrations were similar between the two groups. However, the difference in urine cadmium concentrations was pronounced and statistically significant. Moreover, 30.6% of the AMS data for urine cadmium concentration exceeded the 95th percentile of the KNEHS data. The concentration of lead and cadmium in the residents of the abandoned metal mines, i.e., the vulnerable regions, was higher than that in the general population. It is necessary to monitor and manage the vulnerable regions via a more active and extensive survey system.

Potentially toxic metals and the risk to children's health in a coal mining city: An investigation of soil and dust levels, bioaccessibility and blood lead levels

Coal is a primary energy source in the world. Potentially toxic metals (PTMs) emission from coal mining and combustion are posing a serious public health concern. In order to quantify and evaluate the effect of PTMs on children's health, the concentrations of 12 PTMs (As, Co, Cr, Cu, Mn, Ni, Pb, Sr, Zn, Ca, Fe, and Mg) bound in urban soil and street dust are determined and blood lead levels of these PTMs in 229 children (0-6 years old) are collected from the coal mining city of Yulin, China. In vitro pulmonary bioaccessibilities of PTMs are evaluated by artificial lysosomal fluid and Gamble's solution, and gastrointestinal bioaccessibilities by the unified BAGRE method (UBM); correlations between chemical speciation of PTMs and their bioaccessibility are examined, and children's (0-6 years old) health risks are systematically studied. Similar distribution levels of PTMs are found in soils and dusts, with the most polluted metals being Co, Sr, Ca and Pb. All PTMs (except Cr, Fe) are from the considerable artificial lysosomal fluid extraction both in soil and dust, while Ca and Co are favorably extracted in gastro and intestinal phases than others. Significant correlations are observed between the bioaccessibilities (lung and gastrointestinal) and Fe/Mn hydroxide-bound and carbonate-bound phases, which are key factors influencing and determining PTMs' bioaccessibility. Blood lead levels for children (0-6 years old) are 27.47 (21.65, 33.30) for 0-1 year olds, 32.29 (26.39, 38.19) for 1-2 year olds, 36.99 (28.16, 45.81) for 2-3 year olds, 30.79 (22.56, 39.01) for 3-4 year olds, 27.12 (17.31, 36.93) for 4-5 year olds, 34.59 (24.22, 44.97) for 5-6 year olds and 37.83 (24.15, 51.51) μg/L for 6-7 year olds, respectively, with 3.93%, 3.49%, 4.80%, 2.62%, 1.31%, 1.75% and 1.31% exceeding 50 μg/L, respectively. This indicates that the blood lead levels elevate for 1-2 year and 5-6 year old groups, which should be paid more attention. Although the non-carcinogenic and carcinogenic risks of most PTMs are under the acceptable level, the higher carcinogenic risk of Ni and non-carcinogenic risk of Pb should be monitored continuously. We suggest that further actions will be taken to reduce PTMs exposure for children through sustainable clean and ecological energy technology for coal mining, especially for those infants of 1-2 years old.

Sex differences in the effects of lead exposure on growth and development in young children

The adverse effects of lead exposure on children's health have been widely investigated. Physical growth is a central indicator of health in early childhood. However, studies on the associations between lead exposure and the physical growth of young children are still equivocal. This study aimed to investigate the effects of lead exposure on young children's growth. A cross-sectional survey was conducted, and a total of 1678 young children were recruited. Blood lead levels were determined by graphite furnace atomic absorption spectrophotometry and anthropometric measurements were obtained by nurses. The weight-for-age Z-score (WAZ), height-for-age Z-score (HAZ) and BMI for-age Z-score (BMIZ) of the children were calculated according to World Health Organization standards. Multivariable linear models after adjustment for potential confounders were used to evaluate the associations between lead exposure and childhood anthropometric characteristics. Meanwhile, the sex differences in these associations were also examined. The median blood lead levels in total subjects, in boys and in girls were 46.44, 49.00 and 43.27 μg/L, respectively. After adjusting for confounders, a significantly negative association of blood lead levels with WAZ and HAZ was observed. After stratification by sex, the blood lead levels in children were negatively associated with WAZ and HAZ in boys but not in girls. Meanwhile, we further provide evidence that blood lead levels below 50 μg/L may also have adverse effects on young children's HAZ. Our findings suggest that lead exposure may have sex-specific effects on physical growth in young children and that blood lead level in a low levels may also have adverse effects on children's physical growth and development.

Blood lead level (BLL), δ-aminolevulinic acid dehydratase activity (ALAD), hemoglobin (Hb) and hematocrit (hct) in primary school-children and adult residents living in smelter rural areas in Kosovo

The objective of this study was to investigate the effects of chronic environmental lead (Pb) exposure in blood lead level (BLL), δ-aminolevulinic acid dehydratase (ALAD) activity, hemoglobin (Hb) amount and hematocrit (Hct) value in primary schoolchildren and adults. Blood was obtained for BLL, ALAD, Hb and Hct measurements in 23 primary schoolchildren (girls and boys) and 117 adult residents (women and men) living in three villages (Kelmend, Boletin and Zhazhë) defined by concentric circles 2, 3 and 5 km in radius drawn around from the smelter-refinery complex "Trepça"in Zveçan and in Koliq village 40 km away. As expected, BLLs were substantially higher in the schoolchildren from smelter area compared with control (11 ± 4.2 µg/L and 6.9 ± 1.6 µg/L respectively) and in adult residents from Kelmend, Boletin and Zhazhë (24 ± 11.8, 12 ± 4.5, 11 ± 5.4 and 8.0 ± 2.8 µg/L respectively). Blood ALAD activity of children in Zhazhë is 16% inhibited compared to control and blood ALAD activity in adults in villages from smelter area is 32, 3%, 48, 4% and 17, 8% inhibited compared to control. There is no difference of Hb and Hct values in schoolchildren from Zhazhë and in adult residents from Kelmend and Zhazhë compared with control. Results of this study provide evidence of moderate inverse correlation between BLL and ALAD activity in both examined cohorts from smelter area. The inhibition of ALAD activity in primary schoolchildren and adults occurred at blood lead levels < 24 µg/L; consequently it can cause an increase of δ- Aminolevulinic acid.