Lead Exposure In Children Research Articles

Potential sources of lead in children’s environments, Thimphu, Bhutan

Introduction: There is no level of lead in one’s blood that is known to be safe. Infants and children are exposed to lead through various sources in the environment. Lead-based paint, toys, play equipment, dust, and soil may all be potential sources of lead. Preventing lead exposure is essential to eliminate the permanent and life-long disability caused from lead poisoning. Previous work showed that 44% of children aged 2 - 60 months in a Bhutanese population have dangerously high (greater or equal to 5mg/dL) levels of lead. The sources of this lead toxicity, however, are unknown. This study was carried out to identify potential sources of lead in infants’ and children’s environments at health facilities, early childhood care and development and creche centers, public playgrounds, and schools in Thimphu Dzongkhag. Methods: An environmental survey using a portable X-ray Fluorescence (pXRF) was conducted from May 2021 to April 2022 to identify potential sources of lead in the environment in and around Thimphu, Bhutan. Results: A total of 777 tests were done to identify excessive amounts of lead from various items, including: toys, playground equipment, furniture, paints, and soil. A total of 16 tests had excessive amounts of lead, of which 15 were detected from playground equipment at public playgrounds. The most common color with excessive lead was yellow. Conclusions: Excessive amounts of lead were found in playground equipment as a possible source of lead exposure in children.

Childhood lead exposure is associated with lower cognitive functioning at older ages.

The Flint, Michigan water crisis renewed concern about lead toxicity in drinking water. While lead in drinking water has been shown to negatively affect cognition among children, much less is known about its long-term consequences for late-life cognition. Using a nationally representative sample of U.S. older adults linked to historical administrative data from 1940, we find that older adults who lived as children in cities with lead pipes and acidic or alkaline water-the conditions required for lead to leach into drinking water-had worse cognitive functioning but not steeper cognitive decline. About a quarter of the association between lead and late-life cognition was accounted for by educational attainment. Within the next 10 years, American children exposed to high levels of lead during the 1970s will enter older ages. Our evidence highlights the need for stronger actions to identify interventions to mitigate long-term damage among people at high risk.

’As safe as houses; the risk of childhood lead exposure from housing in England and implications for public health’

Background and aimExposure to lead can harm a child’s health, including damage to the nervous system, delayed growth, hearing loss, and many other adverse health effects, as well as implications for social, economic, educational and social well-being. Lead exposure in children is still a concern and cases require public health management to find the exposure source and interrupt the exposure pathway. Housing characteristics can indicate the presence of lead-contaminated paint and leaded water supply pipes. We aimed to explore the relationship between housing characteristics and elevated blood lead concentration (BLC) in children in England.MethodsWe used a retrospective cohort design and included all cases of lead exposure in children reported to the UK Health Security Agency between 2014 and 2020 via surveillance. A case was a child aged under 16 years, resident in England, BLC of ≥ 0.48 μmol/L (10 µg/dL) and referred for public health management. We collected case demographic details and housing characteristics (age and type). We explored associations between elevated BLC and risk factors, using generalised linear mixed effects models and compared cases’ housing type to that expected nationally.ResultsTwo hundred and sixty-six out of 290 cases met the case definition. There was no difference in BLCs between genders, age groups, deprivation, and housing type. After adjusting for reporting source, housing age and type, cases residing in housing built pre-1976 had a BLC of 0.32 (95%CI 0.02, 0.63) µmols/L (6.63 (95%CI 0.42, 13.0) µg/dL) higher than cases living in housing built after this time. Cases were 1.68 times more likely to be living in terraced housing (housing adjoined to one another) than other children and less likely to live in apartments and detached properties.ConclusionThis study suggests an association between housing characteristics and BLC in children. Housing age and type may act as a proxy for lead exposure risk through exposure to leaded paint, lead water pipes, and lead contaminated dust from indoor and outdoor sources. Public health action should consider targeting families more at risk in older housing by raising awareness of the potential presence of lead pipes and paint. Interventions should include working with wider stakeholders including other housing and environmental professionals, the private sector, as well as parents and carers.

Measuring clinical lead testing coverage to support a population health initiative

Abstract Despite national efforts to reduce lead exposure, some children are still exposed to lead, leading to damage to the nervous system, delayed development, and learning and behavioral problems. CDC has recommended targeting high-risk groups for screening. In addition, Texas Department of State Health Services reported a concerning 17% lead testing coverage of 0-to-5-year-olds in in Harris County (where Houston is located). With the eventual goal of improving lead-related clinical care in a large pediatric hospital network, we asked the following questions: 1) What are the high-risk groups specific to our patient population? 2) For patients who are screened positive, are we adequately confirming the results? 3) For those with confirmed lead exposure, are we providing adequate follow-up care? To answer these questions, we analyzed lead testing and hemoglobin testing data on all children less than 6 years of age from the Texas Children’s Hospital’s electronic health record between 2017 and 2021. Lead screening could be performed on capillary or venous blood, but for elevations on capillary blood we analyzed if the results were confirmed with a venous blood test, as recommended by CDC. We used hemoglobin testing as an indicator of follow-up care of lead-exposed children, because an anemia work-up is recommended for such children. We repeated analysis using two different lead level thresholds, because of recent change to the CDC blood lead reference value from 5 mcg/dL to 3.5 mcg/dL in May 2021. We found 273 children (0.33% of children with capillary blood test) to have cBLL = 3.5mcg/dL. There was a significant racial disparity in the rate of lead screening. For example, the screening rate of Black children was 14%, whereas that of White children were 23%. There was a geographic discrepancy between the areas with most elevated cBLL and testing volume. For example, the area where cBLL was most frequently elevated (3.7%) received less than a fifth of tests compared to the most well-tested area. Only 75% of children with a cBLL = 5mcg/dL received a timely venous blood lead test for confirmation, and this dropped to 43% for children with a cBLL = 3.5mcg/dL. Similarly, only 75% of children with a confirmed venous lead level = 5 mcg/dL received a follow-up repeat vBLL test, and 55% received a follow-up hemoglobin measurement. There is room for improvement in population lead health, in terms of both equity and resource distribution. Improvement of lead-related clinical practice could benefit hundreds of children in the Houston metropolitan area.

The relationship between childhood blood lead levels below 5µg/dL and childhood intelligence quotient (IQ): Protocol for a systematic review and meta-analysis.

The causal association between childhood lead (Pb) exposure and decrements in intelligence quotient (IQ) is well-established, and no safe blood lead level (BLL) in children has been identified. An international pooled analysis of seven prospective studies published by Lanphear et al. in 2005 quantified the relationship between childhood BLL and IQ. Further studies of Pb and IQ have been published more recently with mean BLLs generally lower than in the studies analyzed by Lanphear et al. In this article, we present the protocol for a systematic review to estimate an updated Pb-IQ relationship focusing on BLLs below 5µg per deciliter (µg/dL). What is the quantitative relationship between childhood BLLs and IQ at ages 3-17years at BLLs below 5μg/dL? A comprehensive search of the scientific literature will utilize citation mapping and key word searching. In the citation mapping approach, we will identify seed references that are relevant to our study question, and will then identify more recent references that have cited at least one of the seed references. The key word search will be conducted in the PubMed, Biosis Previews, Scopus, and Web of Science databases. We will also search electronic grey literature databases for conference proceedings, dissertations, and preprints. We will include studies that measured BLL in children at any age, assessed full-scale IQ of the same children (concurrent with or subsequent to BLL sample collection) at ages 3-17, and estimated a continuous quantitative relationship between BLL and IQ. We will consider only studies with a central tendency BLL<10µg/dL. The title and abstract of each record will be reviewed independently by two authors to determine whether the study in question satisfies the inclusion criteria. The full text of each article remaining after title-abstract screening will be reviewed independently by two authors to determine whether the study in question satisfies the inclusion criteria. Two authors will independently extract study characteristics and data from each included study. Studies meeting inclusion criteria will be evaluated for risk of bias (RoB) using the Navigation Guide method applied in a previous systematic review of neurodevelopmental effects (Lam et al., 2017), with adaptation to our study question. Each study will be independently evaluated by two review authors. We intend to conduct a random-effects meta-analysis to summarize the effects of children's exposure to Pb on IQ scores. Additionally, we plan to perform sensitivity analyses using sub-group analyses and/or meta-regression techniques to assess the impact of study design and study population characteristics to examine potential heterogeneity of results across studies. We will assign a confidence level rating (high, moderate, low, or very low) to the effect estimate from the meta-analyses/meta-regressions.

Evaluating the Effectiveness of State-Level Policies on Childhood Blood Lead Testing Rates.

Lead exposure can harm nearly every organ in the human body. Millions of US children are exposed to lead hazards. Identifying lead-exposed children using blood lead testing is essential for connecting them to appropriate follow-up services. However, blood lead testing is not consistently conducted for at-risk children. Thus, determining which policies help improve blood lead testing rates is essential. This analysis provides critical evidence to better understand which state-level policies are more effective at increasing childhood blood lead testing rates. These include metrics, incentives, other managed care organization guidance, provider guidelines, mandatory reporting of results to state health departments, data sharing between Medicaid and other state agencies, and proof of testing for school enrollment. This analysis included 33 states with complete data on the number of children tested for blood lead in 2017-2018 as reported to the Centers for Disease Control and Prevention. Linear regression modeling was conducted to examine associations between testing rates and the aforementioned policies. Fully adjusted models included percentages of the population living in pre-1980 housing, younger than 6 years with Medicaid coverage, and foreign-born. Strongest unadjusted and adjusted regression coefficients were observed for requiring proof of testing for school enrollment (β = .12, P = .03) and metrics (β = .06, P = .01), respectively. Policies associated with higher childhood blood lead testing rates can be used by policy makers; local, state, and federal public health agencies; professional organizations; nonprofit organizations; and others to inform development and implementation of additional policies to increase childhood blood lead testing.

As safe as houses; the risk of childhood lead exposure from housing in England

Background and Aim: Exposure to lead can harm a child’s health, including damage to the nervous system. Lead exposure in children is still a concern and cases require public health management to find the exposure source. Housing characteristics can indicate the presence of lead-contaminated paint and leaded water supply pipes. We aimed to explore the relationship between housing characteristics and elevated blood lead concentration (BLC) in children in England. Methods: We used a retrospective cohort design and included all cases of lead exposure in children reported to the UK Health Security Agency between 2014 and 2020 via surveillance. A case was a child aged under 16 years, resident in England, BLC of &amp;#x2265;0.48&amp;#x3bc;mol/L and referred for public health management. We collected case demographic details and housing characteristics (age and type). We explored associations between elevated BLC and risk factors, using generalised linear mixed effects models and compared cases’ housing type to that expected nationally. Results: 266 cases met the case definition. There was no difference in BLCs between genders, age groups, deprivation and housing type. After adjusting for reporting source, housing age and type, cases residing in housing built pre-1976 had a BLC of 0.32 (95%CI 0.02, 0.63) µmols/L higher than cases living in housing built after this time. Cases were 1.68 times more likely to be living in terraced housing than other children and less likely to live in apartments and detached properties. Conclusion: This study suggests an association between housing characteristics and BLC in children. Housing age and type may act as a proxy for lead exposure risk through exposure to leaded paint, lead water pipes and lead contaminated dust from outdoor sources. Public health action should consider targeting families more at risk in older housing raising awareness of lead pipes and paint. Keywords: Lead, children, housing

Geospatial assessment of racial/ethnic composition, social vulnerability, and lead service lines in New York City

Background/Aim: The state of New York expects to receive $115 million in 2022 from the US Infrastructure Investment and Jobs Act to replace lead water service lines. Our objective was to determine the number and proportion of Potential Lead water service lines across New York City (NYC), and the association between racial/ethnic composition, housing vulnerability, and child lead exposure vulnerability with service line type (Potential Lead, Unknown) at the census tract level for N= 2,083 NYC tracts. Methods: We used conditional autoregressive Bayesian Poisson models to assess the relative risk (median posterior estimates, and 95% credible interval, CrI) of service line type per 20% higher proportion of residents of a given racial/ethnic group, and per higher housing vulnerability and child lead exposure vulnerability index scores corresponding to the interquartile range. We also evaluated flexible natural cubic spline models. Results: Out of 854,672 residential service line records, 136,891 (16.0%) were Potential Lead and 227,443 (26.6%) were Unknown. In fully adjusted models, higher proportions of Hispanic/Latino residents and higher child lead exposure vulnerability were associated with Potential Lead service lines in flexible spline models and linear models (RR 1.15, 95% CrI 1.11, 1.21, and RR 1.11, 95% CrI 1.02, 1.20, respectively). Associations were modified by borough. Potential Lead service lines were associated with higher proportions of non-Hispanic White and non-Hispanic Asian residents in the Bronx and Manhattan, and with higher proportions of non-Hispanic Black residents in Queens. Conclusions: NYC has a high number of Potential Lead and Unknown service lines. Communities with a high proportion of Hispanic/Latino residents and those with children who are already highly vulnerable to lead exposures from numerous sources are disproportionately impacted by Potential Lead service lines. These findings should inform equitable service line replacement efforts across NY state and within NYC. lead; water; environmental justice

Source apportionment based on lead isotope ratios: Could domestic dog's blood lead be used to identify the level and sources of lead pollution in children?

Domestic dogs have been proved to be used as “sentinel organisms” to monitor human lead exposure. However, whether dogs' blood can be used to identify the levels and pollution source of children's lead exposure still needs evidence. To evaluate the potential use of domestic dogs' blood lead as an indicator of lead exposure levels and pollution source of children, accompanying with potential environmental media samples, lead concentrations and isotope ratios (expressed as 207Pb/206Pb, 208Pb/206Pb) in blood were investigated and compared between children and dogs, who came from a Pb–Zn smelter area, a coal fired area and a control area without industrial activity. The results showed that there were significant correlations in blood lead levels (BLLs) between children and dogs in the study areas (p < 0.01). The lead isotope ratios (LIRs) in blood of children and dogs were disparate among the three areas, however, the LIRs of dogs were quite correlated with those of children in each area (p < 0.01). With the comparison of LIRs between potential pollution sources (slag, ore, coal, paint) and blood samples, the identified lead sources based on dogs' blood were found to be coincident with those based on children's blood. Ore smelting and coal combustion were the main sources of lead exposure for the dogs and children in the smelting area, and coal combustion was the predominant source for the children and dogs living in the coal burning area and control area. The results showed that dogs' BLLs might be used to estimate children's BLLs, and blood LIRs measurements of dogs' could be used as an alternative for identifying the sources of children's lead exposure. This study further provided relevant evidence for dogs to be sentinels exposed to human lead exposure and an alternative method for source apportionment of children's lead exposure.

Childhood lead exposure and sex-based neurobehavioral functioning in adolescence

It is well documented that childhood lead exposure is associated with long-term decreases in intelligence quotients (IQ). Lesser known is the relationship with neurobehavioral domains, especially in adolescence. This study sought to identify cross-sectional and longitudinal associations between lead exposure and adolescent executive and visual-motor functioning and examine sex-based differences. Participants were 681 children from Jintan, China who had their blood lead levels (BLLs) assessed at age 3–5 years and 12 years old and neurobehavioral functioning assessed through the University of Pennsylvania Computerized Neurocognitive Battery (PennCNB) platform http://www.med.upenn.edu/bbl at 12 years old. Mean BLLs were 6.41 mcg/dl at age 3–5 years and 3.10 mcg/dl at 12. BLLs at 3–5 years and 12 years were used as predictors for the individual neurobehavioral domains in general linear models while controlling for father and mother occupation and education, residence location, age, and adolescent IQ. Models were run separately for males and females. In adjusted models, males BLLs at 3–5 years were associated with increased time to correctly complete tasks in multiple domains including abstraction/flexibility (β = 19.90, 95% CI( 4.26, 35.54) and spatial processing (β = 96.00, 95% CI 6.18, 185.82) at 12 years. For females in adjusted models, BLLs at 3–5 years were associated with increasing time to correctly complete tasks on the episodic memory domain task (β = 34.59, 95% CI 5.33, 63.84) at 12 years. Two adolescent cross-sectional relationships remained in the adjusted models for males only, suggesting a positive association between BLLs and increasing time for correct responses on the attentional domain task (β = 15.08, 95% CI 0.65, 29.51) and decreasing time for correct responses on the episodic memory task (β = −73.49, 95% CI −138.91, −8.06) in males at 12 years. These associations remained with and without controlling for IQ. These results suggest that lead exposure is associated with overall deficits in male and female neurobehavioral functioning, though in different domains and different timing of exposure.

Racial residential segregation shapes the relationship between early childhood lead exposure and fourth-grade standardized test scores

Racial/ethnic disparities in academic performance may result from a confluence of adverse exposures that arise from structural racism and accrue to specific subpopulations. This study investigates childhood lead exposure, racial residential segregation, and early educational outcomes. Geocoded North Carolina birth data is linked to blood lead surveillance data and fourth-grade standardized test scores (n = 25,699). We constructed a census tract-level measure of racial isolation (RI) of the non-Hispanic Black (NHB) population. We fit generalized additive models of reading and mathematics test scores regressed on individual-level blood lead level (BLL) and neighborhood RI of NHB (RINHB). Models included an interaction term between BLL and RINHB. BLL and RINHB were associated with lower reading scores; among NHB children, an interaction was observed between BLL and RINHB. Reading scores for NHB children with BLLs of 1 to 3 µg/dL were similar across the range of RINHB values. For NHB children with BLLs of 4 µg/dL, reading scores were similar to those of NHB children with BLLs of 1 to 3 µg/dL at lower RINHB values (less racial isolation/segregation). At higher RINHB levels (greater racial isolation/segregation), children with BLLs of 4 µg/dL had lower reading scores than children with BLLs of 1 to 3 µg/dL. This pattern becomes more marked at higher BLLs. Higher BLL was associated with lower mathematics test scores among NHB and non-Hispanic White (NHW) children, but there was no evidence of an interaction. In conclusion, NHB children with high BLLs residing in high RINHB neighborhoods had worse reading scores.

Erratum: Invited Perspective: Identifying Childhood Lead Exposure Hotspots for Action.

Vol. 130, No. 8 ErratumOpen AccessErratum: Invited Perspective: Identifying Childhood Lead Exposure Hotspots for Actionis correction ofInvited Perspective: Identifying Childhood Lead Exposure Hotspots for Action Adrienne S. Ettinger Adrienne S. Ettinger https://orcid.org/0000-0002-0200-8677 Search for more papers by this author Published:16 August 2022CID: 089001https://doi.org/10.1289/EHP11966AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit In the sixth sentence of the seventh paragraph the words “Additional limitations include” were repeated.EHP regrets the error.FiguresReferencesRelatedDetailsRelated articlesInvited Perspective: Identifying Childhood Lead Exposure Hotspots for ActionJul 27, 2022, 12:00:00 AMEnvironmental Health Perspectives Vol. 130, No. 8 August 2022Metrics Downloaded 206 times About Article Metrics Publication History Manuscript received3 August 2022Manuscript accepted3 August 2022Originally published16 August 2022 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Invited Perspective: Identifying Childhood Lead Exposure Hotspots for Action.

Invited Perspective: Identifying Childhood Lead Exposure Hotspots for Action.

Low level lead exposure in early childhood and parental education on adolescent IQ and working memory: a cohort study.

The independent effect of lead exposure and parental education on children's neurocognition is well-documented. However, few studies have examined the combined effect of childhood lead exposure and parental education on adolescent neurocognition, especially in China. Examine both the combined and interactive effect of childhood blood lead levels (BLLs) and parental education on early adolescent neurocognition. 417 children from a longitudinal cohort study in Jintan, China had BLLs measured at 3-5 years and 12 years, parental education levels assessed at 3-5 years, and neurocognitive outcomes tested at 12 years. BLLs at 3-5 years were inversely associated with adolescent IQ (β -0.55 95% CI: -0.97, -0.13) but not working memory (β -0.06 95% CI: -0.23, 0.11) and parental education was positively associated with adolescent IQ (β 0.68 95% CI: 0.19, 1.17) and working memory (β 0.24 95% CI: 0.04, 0.44). BLLs and parental education evidenced combined effects on neurocognition, where children with higher BLLs and lower fathers' education had mean IQ scores 7.84 (95% CI: -13.15, -2.53) points lower than children with lower BLLs and higher fathers' education. There were significant associations between parental education and working memory, however, not with BLLs. The interaction between mother and father high school education and BLLs was insignificant for effects on IQ and working memory. Childhood lead exposure and parental education levels have a combined and long-term impact on IQ, evidence that may partially explain disparities in lead exposure associated outcomes and highlight those children at greatest risk for neurocognitive deficits. Children continue to be exposed to low-levels of environmental lead in China and globally, warranting examination of the impact of such exposures. This paper demonstrates that even relatively low-level lead exposure in early childhood significantly influences adolescent neurocognitive functioning. Furthermore, co-existing social determinant of health-related variables, measured here as parental education, have a combined impact on neurocognition. These results highlight children at greater risk for neurocognitive deficits and demonstrate the need to examine the influence of lead exposure within the broader socio- ecological environment, as these factors work in tandem to influence longer-term neurocognitive outcomes.

Blood Lead Monitoring in a Former Mining Area in Euskirchen, Germany-Volunteers across the Entire Population.

After centuries of mining in the district of Euskirchen, that is, in the communities of Mechernich and Kall, the lead concentration in the soil remains high, often exceeding regulatory guidelines. To clarify the lead body burden among residents in the region, a human biomonitoring study on a voluntary basis was initiated in which the blood lead level (BLL) was assessed. A questionnaire was distributed to evaluate lead exposure routes and confounders. Overall, 506 volunteers participated in the study, of whom 7.5% were children and adolescents, 71.9% were adults from 18 to 69 years, and 19.4% were residents 70 years or older. While the BLLs in the adult population were inconspicuous, among the children and adolescents investigated, 16.7% of the children between 3 and 17 years had BLLs above the recently revised German reference values for BLL in children. These results point towards a higher lead exposure in children living in the region. The hierarchical regression analysis based on the BLL and the questionnaire revealed the significant influence of the factors age, sex, smoking, construction age of the real estate, occupancy, and intensive contact with soil on the BLL. Measures to reduce lead exposure include a focus on improved personal and domestic hygiene to minimize lead intake.

The Association between Lead Exposure and Bone Mineral Density in Childhood and Adolescence: Results from NHANES 1999-2006 and 2011-2018.

There are few studies on lead’s effect on bone mineral density (BMD) in childhood. In this study, we examined the association between lead exposure and BMD among 13,951 children and adolescents aged 8–19 years from NHANES 1999–2006 and 2011–2018. The whole blood lead levels (BLLs) were used as lead exposure biomarkers, and total BMD, subtotal BMD, lumbar spine BMD and limb BMD were used as outcome variables. The survey weighted multivariable generalized additive models (GAMs) with smoothing terms were used to explore the association between blood lead levels and BMDs, adjusted for age, sex, race/ethnicity, height, weight, family-income-to-poverty ratio and blood cadmium. Subgroup analyses stratified by sex and bony sites were further performed. We found an N-shaped curve association between BLLs and total BMD, subtotal BMD and limb BMD for males and females, whereas the association between BLLs and lumbar spine BMD was only significantly negative for females. The findings suggested that lead exposure had different effects on BMD of different bony sites (highly cortical or trabecular regions) in childhood and adolescence and had different effects on the same bone among different ages population and/or at different levels.

Old Adversary, New Challenges: Childhood Lead Exposure and Testing.

Old Adversary, New Challenges: Childhood Lead Exposure and Testing.

Longitudinal association of early childhood lead exposure and adolescent heart rate variability: influence of parental education

Lead exposure has been shown to dysregulate physiological stress responses. However, few studies have investigated the effect of lead exposure on later heart rate variability (HRV), an indicator of a stress response, in large samples of children. Furthermore, the interaction between social environmental factors and lead exposure in childhood, which commonly co-occur, remains understudied. This study examined relationships between childhood lead exposure and early adolescent physiological stress responses at different levels of parental education. Participants were 406 children from Jintan, China. Blood lead levels (BLLs) and parental education data were collected at 3–5 years of age, and HRV outcomes assessed at 12 years via frequency domain measures (LF/HF ratio) collected during an induced stress test. Results show a significant interaction between parental education and BLLs at 3–5 years. This relationship was found to be most consistent for the interaction between BLLs and mother’s years of education for both the planning (β = 0.12, p = 0.046) and speaking (β = 0.11, p = 0.043) phase of the stress task, suggesting that increasing years of mother’s education may enhance the deleterious influence of lead exposure on the HRV frequency measure, LF/HF ratio. This research highlights the complexity in lead exposure induced outcomes.

A new approach to a legacy concern: Evaluating machine-learned Bayesian networks to predict childhood lead exposure risk from community water systems.

Lead in drinking water continues to put children at risk of irreversible neurological impairment. Understanding drinking water system characteristics that influence blood lead levels is needed to prevent ongoing exposures. This study sought to assess the relationship between children's blood lead levels and drinking water system characteristics using machine-learned Bayesian networks. Blood lead records from 2003 to 2017 for 40,742 children in Wake County, North Carolina were matched with the characteristics of 178 community water systems and sociodemographic characteristics of each child's neighborhood. Bayesian networks were machine-learned to evaluate the drinking water variables associated with blood lead levels ≥2μg/dL and ≥5μg/dL. The model was used to predict geographic areas and water utilities with increased lead exposure risk. Drinking water characteristics were not significantly associated with children's blood lead levels ≥5μg/dL but were important predictors of blood lead levels ≥2μg/dL. Whether 10% of water samples exceeded 2ppb of lead in the most recent year prior to the blood test was the most important water system predictor and increased the risk of blood lead levels ≥2μg/dL by 42%. The model achieved an area under the receiver operating characteristic curve of 0.792 (±0.8%) during ten-fold cross validation, indicating good predictive performance. Water system characteristics may thus be used to predict areas that are at risk of higher blood lead levels. Current drinking water regulatory thresholds for lead may be insufficient to detect the levels in drinking water associated with children's blood lead levels.

Hidden toxins: bathtubs as a potential source of lead exposure in children

ABSTRACT Exposure to lead (Pb) remains a serious health concern for children in the United States, particularly those residing in deteriorating housing. While some sources of Pb such as deteriorating paint and lead waterworks are relatively well understood and widely known, other sources remain hidden. One potential hidden source is bathtubs. In this experiment, water resting in a leaded bathtub was tested over a course of 60 min to determine the extent of metal leaching from the tub to the water. Lead levels in the water increased from 6.8 μg/L at baseline to 13 μg/L after resting in the tub for 60 min. Further research is needed to understand if this is typical, the contributing factors, and clinical significance of this finding.