Risk Of Lead Exposure Research Articles

Exposure to lead and cadmium of the Belgian consumers from ceramic food contact articles.

This study was aimed at estimating the intake of lead and cadmium by the Belgian consumers due to the use of ceramic ware. We adopted refined exposure scenarios with respect to migrant concentration, ceramic ware usage, and metal release characteristics. A deterministic estimation was initially performed, followed by probabilistic estimation, if the deterministic estimate exceeds toxicological reference values. Based on the reference doses established by the European Food Safety Authority (EFSA), the risk of lead and cadmium exposure was characterized by the margin of exposure (MOE) and the tolerable weekly intake (TWI), respectively. The probabilistic median and 95th percentile intake of lead were 0.02 and 5.77 μg/kg b.w. per day for adults, and 0.07 and 17.3 μg/kg b.w. per day for children. The MOEs for neurotoxicity, nephrotoxicity and cardiovascular effects were 7.1, 27 and 64 for average consumers, and 0.02, 0.1 and 0.3 for high consumers. The deterministic mean and 95th percentile intake of cadmium were 0.026 (7% TWI) and 0.03 (8% TWI) μg/kg b.w. per day for adults, and 0.08 (22 % TWI) and 0.09 (25 % TWI) μg/kg b.w. per day for children. Considering the exposure of the Belgian population from foodstuffs resulted in the exceedance of the TWI by as much as 20-fold. The risk of exposure to lead and cadmium of the Belgian consumers suggests measures, such as lowering the migration limits for ceramic ware, should be taken to minimize the risk.

Occupational Lead Exposures among University Police Officers and Instructors at an Outdoor Shooting Range in Southcentral Kentucky

There is a potentially high risk of lead exposure among police officers and instructors at an outdoor firing range. In the United States, occupational lead exposure remains an important and significant public health problem. Lead causes both acute and chronic adverse health effects in multiple human organ systems. The Occupational Safety and Health Administration (OSHA) has promulgated a Permissible Exposure Limit and Action Level of 50 µg/m3 and 30 µg/m3 for lead averaged over an 8-hour period, respectively (general industry standards). Excessive lead exposures have been previously reported in several studies that evaluated groups of firearm shooters and instructors at firing ranges. Many of those studies focused mainly on personal lead exposures at either indoor or covered outdoor firing ranges. The present study was conducted with a sample of 17 university police officers (14 shooters and 3 instructors) to assess their occupational lead exposures at an uncovered outdoor firing range in Bowling Green, Kentucky. The study occurred over a period of three days during the months of June and July. The results showed that personal exposures to lead ranged from a concentration of 5.5 to 146 µg/m3. In addition, personal exposures reported for some police officers significantly exceeded OSHA’s general industry lead standards, without consideration of the use of personal protective equipment. The use of copper-jacketed ammunition and personal protective equipment combined with adequate work practices are highly recommended for this group of police officers and instructors. The effective implementation of proactive control measures is necessary to reduce airborne lead levels and invariably minimize potential inhalation and absorption of lead by police officers at firing ranges.

My Private Lead Service Line

Key TakeawaysHomeowners’ decisions to replace their lead service lines (LSLs) can be complicated by factors including understanding of the science, perceptions of lead exposure risks, and cost of the work.First‐draw and five‐minute flush samples may not capture the peak lead concentration, further complicating a customer's replacement decision.In the author's case, sequential sampling indicated that LSL replacement for her home significantly lowered lead concentrations after stagnation.

Delta-aminolevulinic acid dehydratase (ALAD) and vitamin D receptor (VDR) genes polymorphisms in children residing in an abandoned lead‑zinc mine area in Kabwe, Zambia

Lead is a ubiquitous environmental pollutant that poses serious health problems to humans, especially to children. However, genetic variability in individuals varies their susceptibility to lead poisoning. One possible factor is genetic polymorphism. Thus, this study aimed to investigate the association between blood lead level (BLL), and polymorphisms in the delta-aminolevulinic acid dehydratase (ALAD) MspI (rs1800435) and vitamin D receptor (VDR) FokI (rs19735810), BsmI (rs15444410), ApaI (rs7975232) and TaqI (rs731236) genes in children exposed to lead. A total of 140 children (aged 2–10 years) were recruited in areas living closer to and far away from an abandoned lead‑zinc mine in Kabwe, Zambia. Blood samples were collected from each child for BLLs and polymorphisms analysis.All children were homozygous for the ALAD 1 allele, indicating there might be bioavailable lead in the children's blood which can transfer to the soft tissues and the brain. The distribution of the VDR gene polymorphisms showed major alleles prevalence's of 81%, 80%, 68%, and 75% for FokI, BsmI, ApaI, and TaqI polymorphisms, respectively. The aa genotype of VDR ApaI showed significantly higher BLL compared to other genotypes of the VDRs polymorphism. The TaqI - TT genotype was associated with an increase of lead exposure risk in female children (OR = 2.06; 95% CI:1.04–4.06, p = 0.03). The haplotype analysis showed 10 haplotypes with a frequency above 1%, and the FbAt haplotype showed a protective role against lead toxicity. In conclusion, the children, especially female children, which exposed to lead mainly from the abandoned lead‑zinc mine might be at a higher risk of developing lead poisoning. Further, larger scale sample sizes are needed to corroborate the role of ALAD and VDR genetic variants on the implications of lead toxicity in the general population, particularly in children.

Assessment of a Screening Questionnaire to Identify Exposure to Lead in Pregnant Women.

Lead readily crosses the placenta and displays adverse effects on birth outcomes and neurodevelopment. Systematic identification of the risk of exposure during pregnancy is essential but rarely performed, probably due to hospital staff’s workload and their lack of awareness. We aimed to evaluate the relevance of a questionnaire to screen pregnant women for lead exposure. A cross-sectional, multicentre study was carried out on a population of 792 pregnant women from February 2018 to May 2020. A total of 596 women had a blood lead test: 68.5% had blood lead levels below 10 μg/L. The estimated prevalence above 25 µg/L was 4% (95% confidence interval (CI) [2.6–5.9]) and 1.3% had levels above 50 µg/L (95% CI [0.6–2.6]). Multivariate analysis showed that three risk factors significantly increased the probability of blood lead levels above 25 µg/L: the use of traditional cosmetics (adjusted odds ratio [aOR]: 3.90; 95% CI [1.65–9.21]; p = 0.002), degraded old housing (aOR: 2.67; 95% CI [1.19–6.038]; p = 0.018), and (marginally) eating bread more than twice a day (aOR: 2.40; 95% CI [0.96–6.11]; p = 0.060). Our study reveals that a three-question tool can be used to quickly screen for the risk of lead exposure in our population and to trigger lead blood tests and special vigilance during pregnancy follow-up.

Do We Underestimate Risk of Mortality due to Lead Exposure?

Background/Aim: Studies using data from the National Health and Nutrition Examination Survey-III (NHANES-III) have demonstrated significant associations between blood lead levels and increased mortality. However, blood lead reflects primarily recent exposure and lead mobilized from internal organs. Bone lead represents cumulative lead burden and thus is a better biomarker for assessing chronic impacts, but its in vivo assessment requires special K-x-ray fluorescence (KXRF) instrumentation. Our team used KXRF measurements of lead in bone and blood lead levels in participants of the Normative Aging Study to develop an algorithm predicting bone lead levels from a combination of blood lead levels and standard biochemical, hematologic, and questionnaire data. We examined the associations of our algorithm-estimated bone lead levels and mortality in NHANES-III.Methods: We included 11,065 adults followed up to December 31, 2015. Estimated tibia and patella bone lead levels were calculated using our prediction algorithm. We used survey-weighted Cox proportional hazards models to compute hazard ratios (HRs) and 95% confidence intervals (CIs).Results: During the median follow-up of 22.4 years (216,565 person-years), 4,103 participants died (mortality rate=1,895 per 100,000 adults/year). Means (95% CIs) of blood lead, tibia lead, and patella lead were 3.47 μg/dL (3.27-2.67), 2.98 μg/g (2.23-3.75), and 3.04 μg/g (1.94-4.14), respectively. After adjustment for potential confounders, the HRs comparing participants at the 90th vs. 10th percentiles of exposure with regards to all-cause mortality were 1.25 (95% CI: 1.05-1.50) for blood lead, 1.91 (1.36-2.68) for tibia lead, 2.00 (1.45-2.77) for patella lead; for CVD mortality, 1.67 (1.20-2.34) for blood lead, 1.89 (0.98-3.67) for tibia lead, 2.24 (1.26-4.00) for patella lead; and for cancer mortality, 1.35 (0.98-1.84) for blood lead, 2.52 (1.30-4.90) for tibia lead, 2.45 (1.29-4.66) for patella lead.Conclusions: These findings suggest that risk assessment based on blood lead levels may underestimate the true mortality risk of lead exposure.

Blood Lead Testing Among Medically Underserved and Socially Vulnerable Children in the United States 2012-2017.

Lead poisoning can affect intellectual development, growth, hearing, and other health problems. Children 6 years or younger are particularly susceptible to lead poisoning. Health Resources and Services Administration (HRSA)-funded health centers (HCs) serve lower-income, minority, and vulnerable populations across the United States, who may be at a higher risk for lead exposure. At HCs, blood lead testing is monitored; however, little is known about testing rates and characteristics of children tested by HCs. We assessed the prevalence and characteristics of children who received a blood lead test at HCs from 2012 to 2017. We assessed characteristics of children 12 to 60 months of age who had a blood lead test using available self-reported data from HRSA's Health Center Patient Survey (2014-2015). In addition, using HRSA's Uniform Data System, an administrative performance data set, we calculated the annual percentage change of blood lead testing from 2012 to 2017. During 2014-2015, 1.1 million (72.9%; 95% CI, 64.6-81.3) out of the 1.5 million (n = 365 unweighted) eligible children 12 to 60 months of age self-reported receiving a blood lead test at an HRSA-funded HC. There was a significant higher proportion of children with a blood lead test among urban HCs (74.1%; 95% CI, 59.4-88.8) and among those who reported HCs as their usual source of care (99.9%; 95% CI, 99.7-100) (P ≤ .05).The total HC population of children younger than 72 months increased from 2 674 500 in 2012 to 2 989 184 in 2017, and we observed a 34.4% increase in blood lead testing at HRSA-funded HCs over the same time period. HCs play an important role in providing access to blood lead testing in underserved communities in the United States. While HRSA-funded HCs have made substantial efforts to screen and educate patients on lead exposure, nonetheless continued screening and education efforts with both health providers at HCs and parents/guardians are warranted to continue to improve blood lead screening rates among high-risk groups.

Environmental Risk Factors and Psychotic-like Experiences in Children Aged 9–10

Research implicates environmental risk factors, including correlates of urbanicity, deprivation, and environmental toxins, in psychotic-like experiences (PLEs). The current study examined associations between several types of environmental risk factors and PLEs in school-age children, whether these associations were specific to PLEs or generalized to other psychopathology, and examined possible neural mechanisms for significant associations. The current study used cross-sectional data from 10,328 children 9-10 years old from the Adolescent Brain Cognitive Development (ABCD) Study. Hierarchical linear models examined associations between PLEs and geocoded environmental risk factors and whether associations generalized to internalizing/externalizing symptoms. Mediation models examined evidence of structural magnetic resonance imaging abnormalities (eg, intracranial volume) potentially mediating associations between PLEs and environmental risk factors. Specific types of environmental risk factors, namely, measures of urbanicity (eg, drug offense exposure, less perception of neighborhood safety), deprivation (eg, overall deprivation, poverty rate), and lead exposure risk, were associated with PLEs. These associations showed evidence of stronger associations with PLEs than internalizing/externalizing symptoms (especially overall deprivation, poverty, drug offense exposure, and lead exposure risk). There was evidence that brain volume mediated between 11% and 25% of associations of poverty, perception of neighborhood safety, and lead exposure risk with PLEs. Although in the context of cross-sectional analyses, this evidence is consistent with neural measures partially mediating the association between PLEs and environmental exposures. This study also replicated and extended recent findings of associations between PLEs and environmental exposures, finding evidence for specific associations with correlates of urbanicity, deprivation, and lead exposure risk.

Foraging behavior, contaminant exposure risk, and the stress response in wild California condors (Gymnogyps californianus)

Wild California condors (Gymnogyps californianus) are frequently exposed to lead via lead-based ammunition ingestion, and recent studies indicate significant exposure to organochlorines (e.g. dichlorodiphenyldichloroethylene (DDE) and polychlorinated biphenyls (PCBs)) for condors feeding on beach-cast marine mammals. We investigated the influence of contaminant exposure on condor glucocorticoid response through comparisons between wild and captive populations and identification of modifiers of glucocorticoid release in wild condors. We assessed the glucocorticoid response to routine trapping and handling events through measurement of plasma corticosterone and urate glucocorticoid metabolites (GCM). Comparison of peak urate GCM levels showed wild condors exhibited higher responses to handling-associated stressors (2300 ± 1400 ng/g dry wt, average ± SD, n = 27) than captive condors (910 ± 490 ng/g dry wt., n = 6, U = 28, p = 0.003). Multiple linear regression models and an information theoretic approach (AICc) identified several extrinsic variables (e.g., time captive in flight pen before sample collection) that were negatively associated with plasma corticosterone and urate GCM levels in wild condors, which explained ~25% of glucocorticoid variation. When accounting for these extrinsic variables we found that behavioral variables associated with increased lead and organochlorine exposure risk were positively associated with GCM levels, explaining an additional 15% of glucocorticoid variation among wild condors. Days absent from management area, a variable associated with reduced survival attributed to increased lead exposure risk, had a positive influence on plasma corticosterone levels (β = 53 ± 20 SE) and peak urate GCM levels (β = 1090 ± 586 SE). Years observed feeding on marine mammals, a variable positively associated with DDE and PCB exposure, positively influenced peak urate GCM (β = 1100 ± 520 SE) and the magnitude of GCM response (peak GCM - 1st urate GCM) (β = 1050 ± 500 SE). Our findings suggest that individual propensities for contaminant-associated foraging behaviors predict higher stress-induced glucocorticoid levels in wild condors, and that accounting for variables associated with trapping and handling is essential for assessing the impact of environmental stressors such as contaminants on the condor stress response. As an abnormal glucocorticoid response to stress is associated with reduced reproduction and survival in vertebrates, this work indicates the need for further investigations into the physiological impacts of sub-lethal contaminant exposures in scavenging species worldwide.

Increased risk for lead exposure in children through consumption of produce grown in urban soils

Childhood Pb exposure is associated with a multitude of poor health outcomes. In food-insecure areas, growing fresh produce in backyard gardens or on vacant industrial properties is seen as an option for parents. The question arises, could Pb accumulate in consumable tissues of common produce when grown in metals-rich soils at concentrations that would pose a risk to children. This study investigated factors contributing to the accumulation of Pb in consumable tissues of nine common produce crops grown in metals-rich soils from backyard gardens and a former industrial property. Pb in consumable tissues was directly quantified at concentrations less than 1 μg g−1 via X-ray fluorescence (XRF) using protocols specifically developed for use in plant matrices. The accumulation of Pb in prepared raw consumable tissues in three Pb-rich soils was the greatest in modified taproot crops (mean Pb of 11.8 ± 14.6 μg g−1; turnip, beetroot, radish, carrot), with lesser concentrations in fruits (mean Pb of 2.0 ± 3.0 μg g−1; tomato, pepper), and potatoes (mean Pb of 0.7 ± 1.1 μg g−1). An exposure risk evaluation using the USFDA IRL for Pb indicates that consumption of less than 1 g of certain produce grown in this study, including produce grown in garden soils from residential properties, drastically increases the risk of Pb exposure in children. This study further indicates that the proportion of Pb contributed to the daily body burden in children from food is far greater than previously understood, and in all modeled cases, the contribution of Pb from food on a daily basis far outweighs the contribution of Pb from drinking water. For an average child, after addressing over-riding soil/dust impacts, addressing food quality is critical to minimizing Pb exposure.

Social factors shaping the adoption of lead-filtering point-of-use systems: an observational study of an MTurk sample.

Some municipalities are promoting lead-filtering point-of-use (POU) systems to minimize the risk of lead exposure through drinking water, often targeting use at racial minorities and low-income households. However, links among social inequality markers and adoption of these systems are not well understood. Survey data on adoption and use of POU systems were collected from a U.S. Mechanical Turk (MTurk) sample (N = 2,867) in March 2018. We use logistic regression to assess the association of race/ethnicity, socioeconomic status (SES), and lead-filtering POU adoption. We also examined key health behaviors related to POU systems. We found that race and SES are indirectly predictive of lead-filtering POU adoption through the propensity of some respondents to report a residence with a lead service line and levels of concern and knowledge about lead exposure. In addition, individuals with similar levels of concern about lead in water have lower odds of adopting a POU system if they have lower, rather than higher, incomes. Among POU adopters, while confidence in correct use of these devices was relatively high, the frequency of filtered water use for cooking was lower than drinking frequency. Overall, these findings inform health policies aimed at mitigating risk of lead exposure through water.

Assessing the Regulatory Requirements of Lead-Based Perovskite Photovoltaics

Nicole Moody, Samuel Sesena, Dane W. deQuilettes, Benjia Dak Dou, Richard Swartwout, Anna Johnson, Udochukwu Eze, Roberto Brenes, Matthew Johnston, Vladimir Bulovic, and Moungi G. Bawendi are members of Tata-MIT GridEdge Solar, an interdisciplinary research program at the Massachusetts Institute of Technology working toward scalable design and manufacturing of lightweight, flexible solar cells. Joseph T. Buchman and Christy L. Haynes are part of the Center for Sustainable Nanotechnology, a multi-institutional partnership aimed at understanding the fundamental chemical and physical processes that govern the transformations and interactions of nanoparticles in the environment.

The relevance of particle size distribution and bioaccessibility on human health risk assessment for trace elements measured in indoor dust

Trace metal contaminants in indoor dust pose a significant potential exposure risk to people because of the time spent indoors and the readily ingested and inhaled fine-grained composition of indoor dusts. However, there is limited trace metal data available on the specific interaction of dust particle size fraction and their respective bioaccessibility/bioavailability and its consequent effect on health risk assessment. This study addresses this knowledge gap by examining bioaccessible and bioavailable trace element concentrations (As, Cr, Cu, Mn, Ni, Pb, Zn) in 152 discrete size fractions from 38 indoor vacuum samples from a larger dataset (n = 376) of indoor dust from Sydney, Australia. Arsenic, Cu, Ni, Pb and Zn were most concentrated in the 90–150 μm fraction with Cr and Mn being more concentrated in < 45 μm fraction. Dust particle size fractions < 45 μm, 45–90 μm, 90–150 μm and 150–250 μm were analysed for their individual gastric phase (G-alone) in vitro trace element bioaccessibilities. Lead exposure risk was estimated using the United States Environmental Protection Agency's Integrated Exposure Uptake Biokinetic (IEUBK) children's model. Mean Pb bioaccessibility was 59.6%, 42%, 62% and 62.2% for < 45 μm, 45–90 μm, 90–150 μm, and 150–250 μm, respectively. Mean Pb absolute bioavailability (ABA) was lower at 26.2%, 18.4%, 27.2% and 27.3% for size fractions < 45 μm, 45–90 μm, 90–150 μm, and 150–250 μm, respectively. The predicted blood Pb (PbB) levels for a hypothetical child aged 1 to 3 years for each of the dust particle size fractions was > 5 μg/dL. Lead concentrations measured in the selected dust samples show a potential for adverse health impacts on young children with the greatest risk being from indoor dust sized 90–150 μm.

Estimating the causal effect of prenatal lead exposure on prepulse inhibition deficits in children and adolescents

During pregnancy, maternal lead from earlier exposures mobilizes and crosses placental barriers, placing the developing fetus at risk for lead exposure and neurodevelopmental deficits. Some neuronal circuits known to be affected in neurodevelopment disorders can be probed with simple physiological behavioral paradigms. One such neural biomarker is Pre-Pulse Inhibition (PPI), an indicator of adequate sensorimotor gating processing. In clinical studies, deficits in PPI have been associated with neurodevelopmental disorders in human subjects. To our knowledge, no studies have examined the use of PPI as a biomarker of toxicant effects on the brain in epidemiological studies. We aimed to estimate the causal effect of prenatal lead exposure, assessed by maternal cortical bone lead concentrations, on PPI in 279 children from Mexico City. in vivo maternal cortical bone lead measurements were taken at four weeks postpartum at the mid-tibia shaft using a K-Shell X-ray fluorescence instrument. PPI recording occurred in an isolated clinical setting and eye blink responses were measured using electromyography. We assessed if the conditions for causal inference held in our study and used the results of our assessment to estimate the causal effect of prenatal lead exposure on PPI using an ordinary least squares regression model, a marginal structural model, and the parametric g-formula. Results were consistent across the three modeling approaches. For the parametric g-formula, a one standard deviation (10.0 μg/g) increase in prenatal lead significantly reduced PPI by approximately 19.0 % (95 % CI: 5.4 %, 34.3 %). This decrease is similar in magnitude to clinical studies on schizophrenia, which have observed PPI impairments in patients with schizophrenia as compared to controls. Our results are consistent with findings from other studies establishing an association between lead exposure and neurodevelopmental disorders in children and suggest that PPI may be useful as an objective biomarker of toxicant effects on the brain.

Risk of cadmium, lead and zinc exposure from consumption of vegetables produced in areas with mining and smelting past

The study reveals links between disturbed geochemical environment being the result of mining and smelting activities with consumers exposure to toxic and carcinogenic metallic trace elements (MTEs). This study focused on evaluation on vegetable and soil pollution in family allotment gardens (FAGs), considering in the aspects of consumer exposure to cadmium, lead and zinc. Study material consisted of 219 soil samples from FAGs located in one of the most polluted areas in Poland, and 64 samples of edible plants. Contents of analyzed MTEs in topsoil in the studied area were spatially diversified and depended primarily on the location of industrial pollution sources. The average content of cadmium (0.52 mg kg−1 fresh weight) and lead (0.57 mg kg−1 fresh weight) in vegetables exceeded maximum permissible concentrations according to the European Quality Standards. Human health risk assessment was based on three scenarios of dietary exposure to cadmium, lead and zinc. In every scenario the highest average daily dose for all three elements was estimated for potatoes which are one of the main components of Poles’ diet. Presented study showed that consumption of vegetables cultivated in FAGs located in Silesia Province may pose a significant health risk for their consumers.

Probabilistic estimates of prenatal lead exposure at 195 toxic hotspots in low- and middle-income countries

BackgroundPrior estimates of pediatric lead-related disease burden in low- and middle-income countries (LMICs) used population estimates of maternal blood lead levels (BLLs). This approach may underestimate fetal BLLs by not considering potentially high prenatal lead exposure from toxic hotspots. ObjectivesWe developed a probabilistic approach to using the Adult Lead Methodology (ALM) to estimate fetal BLLs from prenatal exposure to lead-contaminated soil at hotspots in the Toxic Site Identification Program (TSIP). MethodsWe created distributions for each ALM parameter using published literature and extracted soil lead measurements from the TSIP database. Each iteration of the probabilistic ALM randomly selected values from the input distributions to generate a site-specific fetal BLL estimate. For each site, we ran 5000 model iterations, producing a site-specific fetal BLL distribution. Results195 TSIP sites, in 33 LMICs, met our study inclusion criteria; an estimated 820,000 women of childbearing age are at risk for lead exposure at these sites. The predicted geometric means (GM) for site-specific fetal BLLs ranged from 3.3 μg/dL to 534 μg/dL, and 98% of sites had estimated GM fetal BLLs >5 μg/dL, the current reference level of the United States Centers for Disease Control and Prevention (CDC), while 11 sites had estimated GM fetal BLLs above the CDC chelation threshold of 45 μg/dL. DiscussionThe TSIP soil lead data and this probabilistic approach to the ALM show that pregnant women living near TSIP sites may have BLLs that put their fetus at risk for neurologic damage and other sequelae, underscoring the need for interventions to reduce lead exposure at toxic hotspots.

Elevated Blood Lead Level Is Associated with Advanced Liver Fibrosis in Patients with Non-Alcoholic Fatty Liver Disease: A Nationwide Survey (NHANES 2011-2016)

Background: Non-Alcoholic Fatty Liver Disease (NAFLD) is most commonly associated with metabolic syndrome, but increasing evidence has also implicated environmental toxicants. In this study, we aim to show that elevated blood Lead levels results in worsening liver fibrosis in patients with NAFLD in a large U.S. population-based cohort. Methods: The National Health and Nutritional Examination Survey (NHANES) is a CDC funded nationally representative survey of the civilian United States population. A total of 30,172 patients were included from this survey. 2,499 non-pregnant individuals ages 20-74 were identified with NAFLD as determined by a Fatty Liver Index score ≥ 60 (reference) and included in this study. Advanced fibrosis was defined by the National Fibrosis Score > 0·676. Student’s T-test was used for continuous and Rao-Scott Chi-Square test for categorical variables. Comparison across quartiles was done with simple linear regression for continuous and Rao-Scott Chi-Square test for categorical variables. Demographics and patient confounders were adjusted using multivariate logistic regression (SAS 9·4) for odds of Advanced Fibrosis with respect to Lead quartile. Findings: Increasing blood Lead levels in NAFLD patients is significantly associated with increasing age, male gender, alcohol, smoking, and lower education. After multivariate adjustment for confounding factors, risk of Advanced Fibrosis significantly increased with Lead exposure, OR 5.93, 95% CI 2.88-12.24 in highest Lead quartile (Q4). In subgroup analysis stratified by BMI, a significant association between advanced liver fibrosis and blood Lead levels was consistently present, Q4 (OR 5·78, 95% CI 0·97-33·63) and Q4 (OR 6·04, 95% CI 2·92-12·48) in BMI 30, respectively. Interpretation: Our findings show that advanced liver fibrosis is six times more likely in NAFLD patients with elevated blood lead levels. NAFLD patients at high risk of Lead exposure may need aggressive screening of blood Pb levels to minimize risk of fibrosis progression. Funding Statement: The authors stated: None. Declaration of Interests: The authors declare that there is no conflict of interest or financial support regarding the publication of this paper. Ethics Approval Statement: The datasets generated during and/or analyzed during the current study are publicly available at [https://www.cdc.gov/nchs/nhanes/index.htm].

Association of lead-exposure risk and family income with childhood brain outcomes.

Socioeconomic factors influence brain development and structure, but most studies have overlooked neurotoxic insults that impair development, such as lead exposure. Childhood lead exposure affects cognitive development at the lowest measurable concentrations, but little is known about its impact on brain development during childhood. We examined cross-sectional associations between brain structure, cognition, geocoded measures of the risk of lead exposure, and sociodemographic characteristics in 9,712 9- and 10-year-old children. Here, we show stronger negative associations of living in high lead-risk census tracts in children from lower- versus higher-income families. With increasing risk of exposure, children from lower-income families exhibited lower cognitive test scores, smaller cortical volume, and smaller cortical surface area. Reducing environmental insults associated with lead-exposure risk might confer greater benefit to children experiencing more environmental adversity, and further understanding of the factors associated with high lead-exposure risk will be critical for improving such outcomes in children.

Implications of legacy lead for children's brain development.

Children at a higher risk of lead exposure develop smaller brain cortical surface area and volume, but only if they are from low-income families.

The role of the South African Medical Research Council in reducing lead exposure and preventing lead poisoning in South Africa.

Even at low levels in blood, lead has been associated with reduced IQ scores, behavioural problems, learning impediments, aggression and violent behaviour. Since the 1980s, the South African Medical Research Council (SAMRC) has been investigating the sources of exposure to lead in South Africa (SA), the groups at highest risk of lead poisoning and a selection of the myriad associated health and social consequences. SAMRC research evidence contributed to the phasng out of leaded petrol, restrictions on lead in paint and other interventions. Subsequently, childhood blood lead levels in SA declined significantly. More recent studies have revealed elevated risks of lead exposure in subsistence fishing and mining communities, users of arms and ammunition, those ingesting certain traditional medicines, and users of certain ceramicware and artisanal cooking pots. Lead-related cognitive damage costs the SA economy ~USD17.7 (ZAR261.3) billion annually, justifying further SAMRC investment in lead exposure research in the country.