Interpreting and managing blood lead levels of less than 10 microg/dL in children and reducing childhood exposure to lead: recommendations of the Centers for Disease Control and Prevention Advisory Committee on Childhood Lead Poisoning Prevention

DNA damage and ALAD polymorphism in high blood lead (Pb) levels of pregnant women attending a tertiary care teaching hospital

Background

Pregnant women are particularly vulnerable to lead toxicity due to increased absorption and decreased elimination of lead from their bodies. The δ-aminolevulinic acid dehydratase (ALAD) gene plays a crucial role in lead metabolism, and its polymorphisms have been implicated in modifying the susceptibility to lead toxicity.

Methods

A cross-sectional study was conducted involving 90 pregnant women and blood samples were collected to measure blood lead levels (BLL) and assessed DNA damage using the comet assay. ALAD polymorphisms were genotyped using PCR-RFLP analysis with MspI restriction enzyme. Statistical analysis, including chi-square tests, logistic regression, and correlation analysis, was performed to determine associations between ALAD polymorphisms, BLL, and DNA damage.

Results

From 90 pregnant women the participants, 16 had high BLL (≥5 μg/dL), while the remaining 74 had normal levels (<5 μg/dL). The ALAD 1-2 genotype was found to be significantly associated with high BLL (p < 0.001). Pregnant women with the ALAD 1-2 genotype exhibited higher levels of DNA damage compared to those with other genotypes (p < 0.001). Furthermore, a positive correlation was observed between the transfer of lead concentration from mother to infant and DNA damage severity (r = 0.511, p < 0.001).

Conclusions

The combination of comet assay and polymorphism analysis offers a comprehensive approach to understanding the impact of lead exposure during pregnancy. These findings underscore the urgent need for effective regulatory measures to reduce lead exposure in the environment and mitigate its adverse effects of lead on maternal and child health.

Identifying Risk Factors for Attention-Deficit/Hyperactivity Disorder (ADHD): a Public Health Concern and Opportunity

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders with significant individual and societal negative impacts of the disorder continuing into adulthood (Danielson et al. in Journal of Clinical Child and Adolescent Psychology, in press; Landes and London in Journal of Attention Disorders 25:3-13, 2021). Genetic and environmental risk (e.g., modifiable exposures such as prenatal tobacco exposure and child maltreatment) for ADHD is likely multifactorial (Faraone et al. in Neuroscience & Biobehavioral Reviews 128:789-818, 2021). However, the evidence for potentially modifiable contextual risks is spread across studies with different methodologies and ADHD criteria limiting understanding of the relationship between early risk factors and later childhood ADHD. Using common methodology across six meta-analyses (Bitsko et al. in Prevention Science, 2022; Claussen et al. in Prevention Science 1-23, 2022; Dimitrov et al. in Prevention Science, 2023; Maher et al. in Prevention Science, 2023; Robinson, Bitsko et al. in Prevention Science, 2022; So et al. in Prevention Science, 2022) examining 59 risk factors for childhood ADHD, the papers in this special issue use a public health approach to address prior gaps in the literature. This introductory paper provides examples of comprehensive public health approaches focusing on policy, systems, and environmental changes across socio-ecological contexts to improve health and wellbeing through prevention, early intervention, and support across development using findings from these meta-analyses. Together, the findings from these studies and a commentary by an author independent from the risk studies have the potential to minimize risk conditions, prioritize prevention efforts, and improve the long-term health and wellbeing of children and adults with ADHD.

Knowledge, Attitudes, Practices, and Prevention Barriers Related to Childhood Lead Poisoning Among Nepali-Speaking Bhutanese Parents in Northeast Ohio, United States

The study objectives were: (i) to develop and administer a survey to assess childhood lead poisoning (CLP) knowledge, attitudes, practices and prevention barriers (KAP-B) among the Nepali-Speaking Bhutanese (NSB) community in Northeast Ohio; and (ii) to examine the association between socio-demographic characteristics of NSB parents and their understanding of CLP as measured by the constructs of knowledge and attitudes. A Nepali language KAP-B questionnaire was developed and 200 NSB parents with at least one child ≤ 7 years of age from the Akron Metropolitan Area, Ohio were interviewed. NSB parents demonstrated a low level of knowledge about CLP prevention measures. While 82% lived in pre-1978 houses, only 27.5% perceived their house/neighborhood to be potentially lead contaminated. Only 33% of the parents reported understanding lead-related information provided by their child's healthcare provider. Low-level CLP awareness among NSB community emphasizes a need for culturally tailored and linguistically appropriate community-level CLP educational intervention programs in this vulnerable community.

Early-Life Lead Exposure: Risks and Neurotoxic Consequences

BACKGROUND

Lead (Pb) does not have any biological function in a human, and it is likely no safe level of Pb in the human body. The Pb exposure impacts are a global concern for their potential neurotoxic consequences. Despite decreasing both the environmental Pb levels and the average blood Pb levels in the survey populations, the lifetime redistribution from the tissues-stored Pb still poses neurotoxic risks from the low-level exposure in later life. The growing fetus and children hold their innate high-susceptible to these Pb-induced neurodevelopmental and neurobehavioral effects.

OBJECTIVE

This article aims to evaluate cumulative studies and insights on the topic of Pb neurotoxicology while assessing the emerging trends in the field.

RESULTS

The Pb-induced neurochemical and neuro-immunological mechanisms are likely responsible for the high-level Pb exposure with the neurodevelopmental and neurobehavioral impacts at the initial stages. Early-life Pb exposure can still produce neurodegenerative consequences in later life due to the altered epigenetic imprints and the ongoing endogenous Pb exposure. Several mechanisms contribute to the Pb-induced neurotoxic impacts, including the direct neurochemical effects, the induction of oxidative stress and inflammation through immunologic activations, and epigenetic alterations. Furthermore, the individual nutritional status, such as macro-, micro-, or antioxidant nutrients, can significantly influence the neurotoxic impacts even at low-level exposure to Pb.

CONCLUSION

The prevention of early-life Pb exposure is, therefore, the critical determinant for alleviating various Pb-induced neurotoxic impacts across the different age groups.

The Historic Built Environment As a Long-Term Geochemical Archive: Telling the Time on the Urban "Pollution Clock"

This study introduces a novel methodology for utilizing historic built environments as reliable long-term geochemical archives, addressing a gap in the reconstruction of past anthropogenic pollution levels in urban settings. For the first time, we employ high-resolution laser ablation mass spectrometry for lead isotope (206Pb/207Pb and 208Pb/206Pb) analysis on 350-year-old black crust stratigraphies found on historic built structures, providing insights into past air pollution signatures. Our findings reveal a gradual shift in the crust stratigraphy toward lower 206Pb/207Pb and higher 208Pb/206Pb isotope ratios from the older to the younger layers, indicating changes in lead sources over time. Mass balance analysis of the isotope data shows black crust layers formed since 1669 primarily contain over 90% Pb from coal burning, while other lead sources from a set of modern pollution including but not limited to leaded gasoline (introduced after 1920) become dominant (up to 60%) from 1875 onward. In contrast to global archives such as ice cores that provide integrated signals of long-distance pollution, our study contributes to a deeper understanding of localized pollution levels, specifically in urban settings. Our approach complements multiple sources of evidence, enhancing our understanding of air pollution dynamics and trends, and the impact of human activities on urban environments.

Zinc and selenium attenuate quaternary heavy metal mixture-induced testicular damage via amplification of the antioxidant system, reduction in metal accumulation, inflammatory and apoptotic biomarkers

Heavy metals (HMs) such as cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg) are highly toxic elements. They are often found together in nature as a heavy metal mixture (HMM) and are known to contribute to subfertility/infertility as environmental pollutants. This study aims to evaluate the potential benefits of treating HMM-induced testicular pathophysiology with zinc (Zn) and/or selenium (Se). Six-week-old male Sprague Dawley rats were grouped into 5 (n = 7). The control group received deionized water, while the other groups were treated with PbCl2 (20 mg kg-1), CdCl2 (1.61 mg kg-1), HgCl2 (0.40 mg kg-1), and Na2AsO3 (10 mg kg-1) in deionized water for 60 days. Additionally, groups III to V received Zn, Se, and Zn/Se, respectively, for 60 days. The study evaluated testis weight, metal accumulation, sperm analysis, FSH, LH, testosterone, prolactin, oxidative stress, antioxidants, pro-inflammatory and apoptotic markers, and presented structural changes in the testis as micrographs. HMM caused a significant increase in testis weight, metal accumulation, prolactin, oxidative stress, and pro-inflammatory and apoptotic markers, while significantly decreasing semen analysis, FSH, LH, and testosterone. Histology showed decreased spermatogenesis and spermiogenesis, as evidenced by the structure of the germ cells and spermatids. However, Zn, Se, or both ameliorated and reversed some of the observed damages. This study provides further evidence for the mitigative potential of Zn, Se, or both in reversing the damage inflicted by HMM in the testis, and as a countermeasure towards improving HM-induced decrease in public health fecundity.

Graphical abstract

Endocytosis-Mediated Transport of Pb in Rat Blood Cells

Blood is an important reservoir for Pb storage in living organisms, and the storage of Pb in blood cells inhibits its discharge from blood. However, the mechanism and molecular targets of Pb entry and exit from blood cells have not been elucidated, which is the major barrier to reducing blood Pb levels in normal human beings. In this study, we explored the effect of Pb-binding proteins on blood Pb levels in rats at environmentally relevant concentrations (0.32 μg/g) by identifying the functions of Pb-binding proteins and validating them with inhibitors. The results showed that Pb-binding proteins in blood cells were mainly related to phagocytosis, while in plasma, they were mainly involved in the regulation of endopeptidase activity. Meanwhile, at the normal population Pb levels, endocytosis inhibitors, endopeptidase activity inhibitors, and coadministration of both can reduce the level of Pb in MEL (mouse erythroleukemia cells) cells by up to 50, 40, and 50%, respectively, while in rat blood, the reduction can reach up to 26, 13, and 32%, respectively. Collectively, these findings reveal that endocytosis increases blood Pb levels and provides a possible molecular target for Pb excretion at ambient concentrations.

Methylation profiles of global LINE-1 DNA and the GSTP1 promoter region in children exposed to lead (Pb)

Lead (Pb) exposure has adverse health effects and altered DNA methylation may contribute to Pb toxicity. LINE-1 is an interspersed repeated DNA that is used as a surrogate marker for estimating genomic DNA methylation levels, and GSTP1 is an isozyme that detoxifies xenobiotics like Pb, and its expression is inhibited by methylation. Thus, to assess the effects of Pb exposure on global hypomethylation and gene-specific promoter hypermethylation, we examined DNA methylation at LINE-1 repetitive elements and the GSTP1 promoter region. Blood samples were obtained from children (N = 123) living in Pb-polluted areas (as exposed children) and children (N = 63) living in Pb-unpolluted areas (as control children) in Kabwe, Zambia. ICP-MS was used to determine blood lead levels (BLLs), and pyrosequencing and a fluorescence-based polymerase chain reaction assay were used to determine levels of LINE-1 methylation and GSTP1 promoter methylation, respectively. Inverse association was found between BLLs and LINE-1 methylation (β = - 0.046, p = 0.006). The highest quartile of BLL had significant hypomethylation of LINE-1 (p for trend = 0.03), suggesting the higher the BLL, the lower LINE-1 methylation. GSTP1 methylation levels did not differ significantly between the two areas (p = 0.504), nor was it associated with Pb poisoning risk (OR = 1.03, p = 0.476), indicating GSTP1 methylation may not be a reliable biomarker of Pb exposure in healthy people. Therefore, Pb-related health problems could result from global DNA methylation changes due to high BLLs.

Effects of single and combined exposure to lead and stress during pregnancy on offspring neurodevelopment

Objective

To assess associations of single and combined exposures to lead and stress during different stages of pregnancy with offspring neurodevelopment.

Methods

We measured prenatal lead (maternal blood-lead in early-pregnancy and umbilical-cord-blood-lead) and maternal stress levels in Shanghai-Birth-Cohort from 2013 to 2016. Maternal stress was assessed using Center-for-Epidemiological-Studies-Depression-Scale and Self-Rating-Anxiety-Scale during mid-pregnancy. The Ages-Stages-Questionnaires-3 (at 6/12-months-of-age) and Bayley-III (at 24-months-of-age) were both used to assess neurodevelopment.

Results

A total of 2132 mother-child pairs with both prenatal lead and stress measurements were included. The geometric-means of blood-lead in early-pregnancy and cord-blood-lead were 1.46 μg/dL and 1.33 μg/dL, respectively. Among the study women, 1.89 % and 0.14 % were screened positive for depression and anxiety. Adjusting for related confounders, the combined exposures had stronger adverse associations with offspring social-emotional skills than single exposures; and the combined exposure in early-pregnancy was associated with greater neurodevelopmental differences than combined exposure around-birth, especially in social-emotion at 24 months-of-age [β (95 %CI): − 10.48(−17.42, −3.54) vs. − 5.95(−11.53, −0.36)].

Conclusions

Both single and combined prenatal exposures to lead/stress impaired infant neuro-development, and the effects of combined exposure may be more profound than single exposures. Combined exposure in early-pregnancy may be associated with worse neurodevelopmental outcomes than combined exposure around-birth, especially in social-emotional development.

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Effects of prenatal single and combined exposure to lead and stress were investigated using a large-scale birth cohort.

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The overall levels of prenatal exposures to lead/stress were relatively low in the Shanghai study women.

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Adverse effects of prenatal combined exposure on offspring neurodevelopment may be more profound than single exposure.

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The impaired neurodevelopment domains in the offspring mainly include social-emotional development.

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Higher levels of impairments were induced when the combined exposure occurred in an earlier stage of pregnancy.

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.

The Performance Comparison of Socioeconomic and Behavioural Factors as Predictors of Higher Blood Lead Levels of 0–6-Year-Old Chinese Children between 2004 and 2014

Childhood lead exposure is a commonly known risk factor affecting children’s health, and 10 governments have taken actions to reduce children’s lead exposure sources. Because lab testing for children’s blood lead levels (BLLs) was not popularized easily, socioeconomic and behavioural factors have been usually used as predictors of screening methods. Along with the overall decreasing trend of children’s BLLs, the lead-exposure-potential-predicting ability of such factors might be limited or changed over time. Our study aims to compare the predicting ability of multiple factors, including the living environment, economic disparity and personal behaviour differences between 2004 and 2014. With potential predicting factors identified, it could provide direction in identifying individual children facing high-risk lead exposure in the unit of clinics or communities of China. The study was first conducted in 12 cities in China in 2004 and then repeated in 2014 in the same 12 cities with the same method. In total, 27,972 children aged under 7 years were included in this study. With confounding factors adjusted, the child’s age, the family’s socioeconomic status and the child’s personal hygiene habit, especially biting toys, continued to be important predictors of higher blood lead levels among Chinese children. The sex of the child was no longer a predictor. Factors such as the father’s occupational contact with lead, residence near the main road and taking traditional Chinese medicine had the potential to be new predictors.

Assessment of Urinary Lead (Pb) and Essential Trace Elements in Autism Spectrum Disorder: a Case-Control Study Among Preschool Children in Malaysia

Lead (Pb) is a heavy metal which is abundant in the environment and known to cause neurotoxicity in children even at minute concentration. However, the trace elements calcium (Ca), magnesium (Mg), zinc (Zn) and iron (Fe) are essential to children due to its protective effect on neurodevelopment. The primary objective of this study was to assess the role of Pb and trace elements in the development of autism spectrum disorder (ASD) among preschool children. A total of 81 ASD children and 74 typically developed (TD) children aged between 3 and 6 years participated in the study. Self-administered online questionnaires were completed by the parents. A first-morning urine sample was collected in a sterile polyethene urine container and assayed for Pb, Ca, Mg, Zn and Fe using an inductively coupled plasma mass spectrometry (ICP-MS). Comparisons between groups revealed that the urinary Pb, Mg, Zn and Fe levels in ASD children were significantly lower than TD children. The odds of ASD reduced significantly by 5.0% and 23.0% with an increment of every 1.0 μg/dL urinary Zn and Fe, respectively. Post interaction analysis showed that the odds of ASD reduced significantly by 11.0% and 0.1% with an increment of every 1.0 μg/dL urinary Zn and Pb, respectively. A significantly lower urinary Pb level in ASD children than TD children may be due to their poor detoxifying mechanism. Also, the significantly lower urinary Zn and Fe levels in ASD children may augment the neurotoxic effect of Pb.

Preliminary Study of Lead-Contaminated Drinking Water in Public Parks-An Assessment of Equity and Exposure Risks in Two Texas Communities

Safe drinking water is celebrated as a public health achievement and is a top priority for the Environmental Protection Agency. Yet today, lead (Pb) contaminated drinking water has the potential to be a public health crisis in the United States. Despite efforts to provide safe drinking water, update water infrastructure, and ensure strict drinking water regulations, there are incidents of unsafe lead levels and reports of associated adverse health effects. While there has been increased attention paid to the quality of drinking water within individuals’ homes, little research has examined the presence and concentration of lead in water from drinking fountain sources located in public parks. In this study, we sampled drinking water from every accessible public park in the Bryan/College Station (BCS), TX metropolitan area (N = 56). With a lower detection level of 2.0 μg/L, we discovered a mean lead concentration of 1.3 μg/L across all sites and a maximum of 8.0 μg/L. Furthermore, neighborhoods below the median income for BCS were twice as likely to have detectable lead levels in their water and had 1.5 times the mean concentration. This study underscores the need for action and supports previous studies that have identified a disparate burden to lead exposure among low socioeconomic populations within the United States. By examining the water quality in drinking fountains in publicly accessible parks, the results of our study provide public health professionals with important information about where infrastructure should be improved and the potential harms of lead in drinking fountain water.

Increased Risk of Sub-Clinical Blood Lead Levels in the 20-County Metro Atlanta, Georgia Area-A Laboratory Surveillance-Based Study

Lead (Pb) is a naturally occurring, highly toxic metal that has adverse effects on children across a range of exposure levels. Limited screening programs leave many children at risk for chronic low-level lead exposure and there is little understanding of what factors may be used to identify children at risk. We characterize the distribution of blood lead levels (BLLs) in children aged 0–72 months and their associations with sociodemographic and area-level variables. Data from the Georgia Department of Public Health’s Healthy Homes for Lead Prevention Program surveillance database was used to describe the distribution of BLLs in children living in the metro Atlanta area from 2010 to 2018. Residential addresses were geocoded, and “Hotspot” analyses were performed to determine if BLLs were spatially clustered. Multilevel regression models were used to identify factors associated with clinical BBLs (≥5 µg/dL) and sub-clinical BLLs (2 to <5 µg/dL). From 2010 to 2018, geographically defined hotspots for both clinical and sub-clinical BLLs diffused from the city-central area of Atlanta into suburban areas. Multilevel regression analysis revealed non-Medicaid insurance, the proportion of renters in a given geographical area, and proportion of individuals with a GED/high school diploma as predictors that distinguish children with BLLs 2 to <5 µg/dL from those with lower (<2 µg/dL) or higher (≥5 µg/dL) BLLs. Over half of the study children had BLLs between 2 and 5 µg/dL, a range that does not currently trigger public health measures but that could result in adverse developmental outcomes if ignored.

Childhood maltreatment and lead levels in middle adulthood: A prospective examination of the roles of individual socio-economic and neighborhood characteristics

BACKGROUND

Lead is a common environmental hazard because of its past use as an additive to gasoline and household paint. Some evidence suggests that children with histories of child abuse and neglect are at elevated risk for residence in communities and households with less desirable characteristics and high levels of exposure to environmental hazards and toxins.

OBJECTIVES

To understand whether childhood maltreatment leads to higher levels of household dust lead and blood lead in adulthood and the extent to which characteristics of a person's physical environment or individual level socio-economic status (SES) (based on unemployment, poverty, and receipt of public assistance) contribute to understanding the relationship.

METHODS

A large prospective cohort design study in which abused and neglected children (ages 0-11) were matched with non-maltreated children and assessed in adulthood. Objective and subjective neighborhood characteristics were assessed at approximate age 40 and household dust lead (cleaned and less often cleaned) and blood lead levels were measured at age 41. Blood was collected through venipuncture by a registered nurse as part of a medical status exam.

RESULTS

Childhood maltreatment predicted higher levels of dust lead in less often cleaned household places, residence in worse neighborhoods defined by objective (census tract data) and subjective (reports of physical disorder and lack of social cohesion and control), and higher levels of poverty, receiving public assistance, and unemployment. Only objective neighborhood characteristics mediated the relationship between childhood maltreatment and dust lead level in adulthood. There were also significant paths from objective neighborhood disadvantage and individual level SES to higher levels of blood lead.

DISCUSSION

Thirty years after their childhood experiences, individuals with documented histories of childhood maltreatment are at higher risk for living in environments as adults with elevated lead levels that may impact other aspects of their lives and compromise their health.

The Effect of Whole Blood Lead (Pb-B) Levels on Changes in Peripheral Blood Morphology and Selected Biochemical Parameters, and the Severity of Depression in Peri-Menopausal Women at Risk of Metabolic Syndrome or with Metabolic Syndrome

The aim of our study was to assess the impact of whole blood lead (Pb-B) levels on changes in peripheral blood morphology and selected biochemical parameters, and the severity of depression in peri-menopausal women at risk of metabolic syndrome (pre-MetS) or with metabolic syndrome (MetS). The study involved 233 women from the general population of the West Pomeranian Province (Poland) aged 44–65 years. The intensity of menopausal symptoms and the severity of depression was examined using the Blatt–Kupperman Index (KI) and the Beck Depression Inventory (BDI). C-reactive protein (CRP), insulin, glucose, glycated hemoglobin (HbA1C), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, triglyceride levels (TG), cortisol, morphology of blood cells and homeostasis model assessment for insulin resistance (HOMA-IR) and Pb-B was measured. Women with MetS had higher levels of glucose, HbA1C, HDL, LDL, TG, cortisol, insulin and higher HOMA-IR. No significant differences in Pb-B were observed between pre-MetS and the control group, and between pre-MetS and the MetS group. A significant correlation was noticed between Pb-B vs. the percentage of monocytes in blood, and blood cortisol levels in women with MetS; Pb-B vs. lymphocyte count and HbA1C in the pre-MetS group, as well as in the BDI scores between the MetS and pre-MetS group. We cannot clearly state that exposure to Pb is an environmental factor that can be considered as a risk factor for MetS in this studied group.

Highly sensitive detection of Pb2+ and Cu2+ based on ZIF-67/MWCNT/Nafion-modified glassy carbon electrode

A series of different facile modification layers (MLs) was designed to gradually increase the electrochemical sensing performance of glassy carbon electrode (GCE) for simultaneously detecting Pb²⁺ and Cu²⁺. ML designs were mainly a different combination of ZIF-67, MWCNT and Nafion, and their different electrochemical sensing performances were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), square wave stripping voltammetry (SWSV) and chronocoulometry. The fabricated sensor, which modified with ZIF-67/MWCNT and Nafion layer, exhibited the biggest response peak current to Pb²⁺ and Cu²⁺. In addition, it displayed a wide linear detection range of 1.38 nM-5 μM for Pb²⁺ and 1.26 nM-5 μM for Cu²⁺, a detection accuracy of about 1 nM for both Pb²⁺ and Cu²⁺, and an excellent stability for both Pb²⁺ and Cu²⁺. We also analyzed the real water sample taken from Changchun's Sanjia Lake and Yan Lake. We believe this ML design provides instruction for building high-performance electrochemical sensing systems.

Lead Exposure in Newly Resettled Pediatric Refugees in Syracuse, NY

Lead is a major environmental toxin that presents numerous health consequences for children. Refugee children are at a risk of lead poisoning post-resettlement due to urban housing and environmental inequalities stemming from lack of funding, legislation, and advocacy. This article addresses lead exposure upon arrival and post-resettlement in 705 refugee children (age 0-16 years) attending a university clinic in Syracuse, NY, a city with a large refugee population. 17% of the newly arrived children had elevated blood lead levels (BLLs) (≥ 5 µg/dL); 10% had elevated BLL upon follow-up; 8.3% of the children's follow-up elevated BLL were new exposures. 30% were found to have increased BLL at follow-up regardless of arrival status. An analysis of new exposures found a significant proportion of children would have been missed on routine screening that targets children < 2 years old. Primary prevention efforts are needed to prevent exposure and address risks to improve the health of all children locally, including newly resettled refugees.

Zhiqi Granules Decreased Lead Level but Increased Iron Level in Serum of Chinese Children with Moderately Elevated Blood Lead Levels

To observe and compare the effects of healthy instruction and Zhiqi granules on lead, calcium, iron, and zinc levels in serum of children with moderately elevated blood lead levels (BLLs). At the same time, the possible mechanisms were discussed. A total of 60 eligible boys aged 4-6 years were selected and divided into two groups (the healthy instruction group and the Zhiqi group) randomly. The boys in the healthy instruction group only received the healthy instruction. Besides the healthy instruction, the boys in the Zhiqi group received 2 g Zhiqi granules orally one time daily. The study lasted for 4 weeks. BLL and serum iron, zinc, and calcium levels of the subjects in the two groups before and after interventions were measured and compared. After the interventions, the BLL in the Zhiqi group lowered significantly, but the decrease of the BLL in the healthy instruction group is not significant, and there was a significant difference in the BLL between the two groups. When the trial was completed, the serum iron level in the Zhiqi group increased significantly, but that in the healthy instruction group changed slightly, and a significant difference was seen between the two groups. There were no significant differences in both serum Ca and Zn levels in these two groups before and after the interventions. Meanwhile, there were no significant differences in serum Ca and Zn levels between the two groups after the interventions. The results suggested that daily intake of Zhiqi granules for 4 weeks together with healthy instruction resulted in a decrease of the BLL and an elevation of the serum iron level.

Risky bismuth: Distinguishing between lead contamination sources in soils

In a broad environmental study in St. Joseph County, Indiana, elemental data from ∼2000 soil samples and ∼800 paint samples were collected with X-ray Fluorescence (XRF) spectroscopy. The observed lead concentrations were compared to other elemental concentrations in these data. A strong correlation between lead and bismuth concentrations was observed in a subset of the soil samples and in nearly all of the paint samples, with lead levels approximately 150 times higher than bismuth. However, some soil samples contained lead with no bismuth present. Since most lead sources likely contain bismuth as an impurity from refining of native lead ore, but leaded gasoline does not contain any bismuth impurities due to the manufacturing process of tetraethyl lead, it may be possible to distinguish environmental lead sources by XRF. To test if leaded gasoline could be the source of lead in the subset of soil samples containing no bismuth, leaded paint samples were analyzed with Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES), which confirmed the presence of bismuth in leaded paint. Aviation gasoline, which contains tetraethyl lead, was also analyzed by ICP-OES to confirm the absence of bismuth in leaded gasoline. This discovery suggests that XRF can be used to rapidly distinguish different legacy lead contamination sources from one another. For low lead concentrations, elemental measurements of bismuth by ICP-OES can be used in environmental forensics to distinguish leaded gasoline contamination from other sources of lead.

Environmental and biological monitoring in the workplace: A 10-year South African retrospective analysis

This report is an overview of requests for biological and environmental monitoring of hazardous chemicals, submitted to the National Institute for Occupational Health, Analytical Services Laboratory for testing from the years 2005 to 2015. The report discusses the nature of tests requested and implications for workers’ health and environment, as well as potential impact of the uncertainties associated with monitoring of hazardous chemicals. This is a retrospective, descriptive, qualitative and quantitative audit of all samples received and tests performed retrieved from records of analysis by the laboratory. The study sample consisted of 44,221 samples. The report indicates that throughout the interrogation period the demand for biological monitoring was higher than that for environmental monitoring, with more requests for toxic metals than organic pollutants. Toxic metal testing was highest for mercury, followed by manganese, lead, aluminium and arsenic. The highest number of tests for organic pollutants was conducted for pesticides followed by toluene and xylene. The study has also revealed that the scope of tests requested is rather narrow and does not reflect the broad spectrum of South Africa’s industrial diversity. Having identified possible reasons for underutilization, a number of reforms that could enhance the laboratory’s performance have been addressed.

Inconsistent screening for lead endangers vulnerable children: policy lessons from South Bend and Saint Joseph County, Indiana, USA

Lead exposure is a major health hazard affecting children and their growth and is a concern in many urban areas around the world. One such city in the United States (US), South Bend Indiana, gained attention for its high levels of lead in blood and relatively low testing rates for children. We assessed current lead screening practices in South Bend and the surrounding St. Joseph County (SJC). The 2005-2015 lead screening data included 18,526 unique children. Lead screening rates ranged from 4.7 to 16.7%. More than 75% of children had 'elevated blood lead levels' (EBLL) ≥ 1 micrograms per deciliter (µg/Dl) and 9.7% had an EBLL ≥ 5 μg/dL. Over 65% of the census tracts in SJC had mean EBLL ≥ 5 μg/dL, suggesting widespread risk. Inconsistent lead screening rates, coupled with environmental and societal risk factors, put children in SJC at greater risk for harmful lead exposure than children living in states with provisions for universal screening. Indiana and other states should adhere to the US Centers for Disease Control's guideline and use universal lead testing to protect vulnerable populations.

Elevated Blood Lead Levels Among Resettled Refugee Children in Ohio, 2009-2016

Objectives. To assess the prevalence of and the demographic factors for elevated blood lead level (EBLL; ≥ 5 µg/dL) at resettlement among newly admitted refugee children. Methods. This cross-sectional study used data from the postresettlement refugee medical screening of 5661 children resettled in Ohio from 2009 to 2016. We computed prevalence of EBLL and adjusted prevalence ratio with modified Poisson regression modeling. Results. Overall, 22.3% of children younger than 18 years and 27.1% of those younger than 6 years had an EBLL. Children resettled from a South Asia region including Afghanistan (EBLL prevalence = 56.2%; 95% confidence interval [95% CI] = 48.1%, 64.3%), Nepal (44.0%; 95% CI = 33.7%, 54.1%), Bhutan (32.8%; 95% CI = 30.4%, 35.9%), and Burma (31.8%; 95% CI = 27.5%, 35.9%) had the highest prevalence of EBLLs. In addition, those younger than 6 years (prevalence ratio [PR] = 2.0; 95% CI = 1.6, 2.6), male (PR = 1.3; 95% CI = 1.1, 1.4), and screened within 30 days of arrival (PR = 1.7; 95% CI = 1.1, 2.5) had significantly higher EBLL prevalence than did children aged 13 years and older, female, and screened 90 days after arrival. Conclusions. The overall high proportion of EBLL and variation in EBLL by country of origin among resettled refugee children in the United States warrant comprehensive, yet tailored, guidelines for health professionals and resettlement and government agencies for better prevention and awareness programs targeting these high-risk children.

Environmental and take-home lead exposure in children living in the vicinity of a lead battery smelter in Serbia

Blood lead levels (BLLs) have been falling steadily worldwide due to restricted use of lead (Pb) and its compounds. although they remain above preindustrial Pb levels. Elevated BLL can still be found in children living near secondary Pb smelters that represent around 50% of Pb production. There have been no studies on Pb exposure in children living in Serbia ever since the 1980s. The aim of this study was to evaluate the BLLs in children living in two villages in Serbia (Zajača, the location of a secondary lead smelter, and Paskovac, 5 km away), identify the primary determinants of children's BLLs, and investigate the impact of BLLs on children's health symptoms and school achievement. The study was conducted in 2011 on 127 children, aged 1-18 years, whose BLLs were measured using inductively coupled argon plasma mass spectrometry (ICP-MS). The median BLL in children was 12 μg/dl, with a significantly higher value of 17.5 μg/dl in Zajača, compared to 7.6 μg/dl in Paskovac. Only 1 out of 75 and 12 out of 52 children from Zajača and Paskovac, respectively, had BLLs below the CDC recommended 5 μg/dl level. Living near the smelter resulted in 19 times, and having a father who works in the plant 4 times higher odds of elevated BLLs. No significant effects of elevated BLLs health symptoms were seen in this study. BLLs of children living near a battery recycling plant in Serbia, an upper-middle income European country, were in the range and even higher than those of children living in developing countries. For the first time, the contribution of environmental and take-home lead exposure was quantified using mixed-effect modeling, and our results indicate a contribution of 25-40% of the take-home lead exposure to the BLLs of children living in the vicinity of a secondary lead smelter.

Toxic metal(loid)-based pollutants and their possible role in autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social interaction, verbal and non-verbal communication, and stereotypic behaviors. Many studies support a significant relationship between many different environmental factors in ASD etiology. These factors include increased daily exposure to various toxic metal-based environmental pollutants, which represent a cause for concern in public health. This article reviews the most relevant toxic metals, commonly found, environmental pollutants, i.e., lead (Pb), mercury (Hg), aluminum (Al), and the metalloid arsenic (As). Additionally, it discusses how pollutants can be a possible pathogenetic cause of ASD through various mechanisms including neuroinflammation in different regions of the brain, fundamentally occurring through elevation of the proinflammatory profile of cytokines and aberrant expression of nuclear factor kappa B (NF-κB). Due to the worldwide increase in toxic environmental pollution, studies on the role of pollutants in neurodevelopmental disorders, including direct effects on the developing brain and the subjects' genetic susceptibility and polymorphism, are of utmost importance to achieve the best therapeutic approach and preventive strategies.

Environmental and biological monitoring in the workplace: A 10-year South African retrospective analysis

This report is an overview of requests for biological and environmental monitoring of hazardous chemicals, submitted to the National Institute for Occupational Health, Analytical Services Laboratory for testing from the years 2005 to 2015. The report discusses the nature of tests requested and implications for workers’ health and environment, as well as potential impact of the uncertainties associated with monitoring of hazardous chemicals. This is a retrospective, descriptive, qualitative and quantitative audit of all samples received and tests performed retrieved from records of analysis by the laboratory. The study sample consisted of 44,221 samples. The report indicates that throughout the interrogation period the demand for biological monitoring was higher than that for environmental monitoring, with more requests for toxic metals than organic pollutants. Toxic metal testing was highest for mercury, followed by manganese, lead, aluminium and arsenic. The highest number of tests for organic pollutants was conducted for pesticides followed by toluene and xylene. The study has also revealed that the scope of tests requested is rather narrow and does not reflect the broad spectrum of South Africa’s industrial diversity. Having identified possible reasons for underutilization, a number of reforms that could enhance the laboratory’s performance have been addressed.

Source identification of human exposure to lead in nine Cree Nations from Quebec, Canada (Eeyou Istchee territory)

While policies to decrease lead in the environment have been implemented to reduce human exposure to various lead sources, the use of lead ammunition to harvest wild game may continue to contribute significantly to human blood lead levels (BLLs). As part of a multi-community environment-and-health study, BLLs representing all age groups were evaluated in the nine Cree Nations located in the James and Hudson Bay regions of Quebec, Canada. Personal, market food, traditional food and 24-h recall questionnaires were administered. Predictor variables were assessed for various exposure sources, including diet and hunting practices. Elevated BLLs were observed in association with increased hunting status, use of firearms and leaded ammunition, and consumption of traditional foods. Significant differences were observed between all communities, age groups and sexes. Recommendations include educational campaigns that promote switching to non-lead ammunition and, if lead ammunition continues to be used, careful removal from tissues of pellets, bullet fragments and ammunition paths.

An Update on Childhood Lead Poisoning

Childhood lead poisoning is a multi-faceted, complex condition, which affects not only the child's health and well-being, but also the family's housing security, economic status, job security, and stress level. This review updates the emergency department clinician on the management of childhood lead poisoning. Infants and children are at higher risk than adults for lead exposure due to their smaller size and proportionately larger dose of ingested toxins, their proximity to ground dirt and indoor dust, their energy and curiosity, their oral exploratory and pica behaviors, their proportionately larger daily water and milk intake, and dietary preferences that differ markedly from those of adults. Pediatric health care providers working in the emergency department can provide medical management, as well as preventive counseling and guidance, to parents of children presenting with evidence of acute or chronic lead poisoning.

Using Public Health Data for Soil Pb Hazard Management in Ohio

OBJECTIVES

To evaluate how frequently elevated soil lead (Pb) hazards (≥400 ppm Pb) were identified in existing blood Pb site investigations in Ohio.

DESIGN

This study evaluated 3050 site investigations from the Ohio Department of Health for children with blood Pb levels at or above 10 μg dL that contained bare soil Pb data.

SETTING

Data were collected from existing databases maintained by the Ohio Department of Health.

PARTICIPANTS

All data were de-identified prior to analysis. The data used included blood Pb level test results for children (18 years or younger) in Ohio, with most data coming from children younger than 6 years.

MAIN OUTCOME MEASURES

The main outcome measures were blood Pb levels and identified Pb concentrations in environmental media, including soil, paint, and dust.

METHODS

Data were organized and summarized according to county. Summary statistics were generated on the basis of type of environmental media and county.

RESULTS

Soil samples were collected in approximately 5% of all blood Pb cases in Ohio between 1999 and 2015. Median bare soil Pb was 1030 mg Pb kg (range, 0-345 021 mg Pb kg soil). Fifty-six of Ohio's 88 counties had at least 1 soil sample above 10 000 ppm (mg Pb kg). Multiple Pb hazards were identified, including bare soil (74% frequency), deteriorated exterior Pb paint (74%), deteriorated interior Pb paint (72%), and settled Pb dust (72%). Bare soil collected from identified dripline areas contained 2638 ppm Pb above soils collected from bare soil play areas (P = .02). Ninety assessments (3%) contained a bare soil hazard, with no other identified hazards. No trend was found comparing county mean or median Pb with county population. Previously identified high-risk counties for elevated blood Pb levels did not have an elevated prevalence of bare soil Pb hazards compared with other counties (P = .64).

CONCLUSIONS

Site investigators should anticipate finding and managing elevated bare soil Pb in locations throughout Ohio. When communicating with the public about bare soil Pb hazards, practitioners and policy makers should emphasize the importance of addressing all potential Pb exposure sources. Findings demonstrate the importance of the individual home environment for exposure, as previously identified high-risk counties for elevated blood Pb levels were not different from other counties.

Soil solution interactions may limit Pb remediation using P amendments in an urban soil

Lead (Pb) contaminated soils are a potential exposure hazard to the public. Amending soils with phosphorus (P) may reduce Pb soil hazards. Soil from Cleveland, OH containing 726 ± 14 mg Pb kg^-1 was amended in a laboratory study with bone meal and triple super phosphate (TSP) at 5:1 P:Pb molar ratios. Soil was acidified, neturalized and re-acidified to encourage Pb phosphate formation. PRSTM-probes were used to evaluate changes in soil solution chemistry. Soil acidification did not decrease in vitro bioaccessible (IVBA) Pb using either a pH 1.5, 0.4 M glycine solution or a pH 2.5 solution with organic acids. PRSTM-probe data found soluble Pb increased 10-fold in acidic conditions compared to circumnetural pH conditions. In acidic conditions (p = 3-4), TSP treated soils increased detected P 10-fold over untreated soils. Bone meal application did not increase PRSTM-probe detected P, indicating there may have been insufficient P to react with Pb. X-ray absorption spectroscopy suggested a 10% increase in pyromorphite formation for the TSP treated soil only. Treatments increased soil electrical conductivity above 16 mS cm^-1, potentially causing a new salinity hazard. This study used a novel approach by combining the human ingestion endpoint, PRSTM-probes, and X-ray absorption spectroscopy to evaluate treatment efficacy. PRSTM-probe data indicated potentially excess Ca relative to P across incubation steps that could have competed with Pb for soluble P. More research is needed to characterize soil solutions in Pb contaminated urban soils to identify where P treatments might be effective and when competing cations, such as Ca, Fe, and Zn may limit low rate P applications for treating Pb soils.

Bullet fragment-induced lead arthropathy with subsequent fracture and elevated blood lead levels

Lead foreign bodies in joint spaces, often due to projectiles such as bullets, may cause localized arthropathy. There are no reports of joint fracture related to lead arthropathy. Additionally, lead foreign bodes embedded in the joint space may be a source of systemic lead absorption, causing elevated blood lead levels and toxicity to other organs. We present a young adult patient with retained left hip joint bullet fragments who developed suspected lead arthropathy and subsequent acute left hip fracture, as well as systemic lead absorption demonstrated by elevated blood lead levels.

Lead Exposure during Early Human Development and DNA Methylation of Imprinted Gene Regulatory Elements in Adulthood

BACKGROUND

Lead exposure during early development causes neurodevelopmental disorders by unknown mechanisms. Epidemiologic studies have focused recently on determining associations between lead exposure and global DNA methylation; however, such approaches preclude the identification of loci that may alter human disease risk.

OBJECTIVES

The objective of this study was to determine whether maternal, postnatal, and early childhood lead exposure can alter the differentially methylated regions (DMRs) that control the monoallelic expression of imprinted genes involved in metabolism, growth, and development.

METHODS

Questionnaire data and serial blood lead levels were obtained from 105 participants (64 females, 41 males) of the Cincinnati Lead Study from birth to 78 months. When participants were adults, we used Sequenom EpiTYPER assays to test peripheral blood DNA to quantify CpG methylation in peripheral blood leukocytes at DMRs of 22 human imprinted genes. Statistical analyses were conducted using linear regression.

RESULTS

Mean blood lead concentration from birth to 78 months was associated with a significant decrease in PEG3 DMR methylation (β = -0.0014; 95% CI: -0.0023, -0.0005, p = 0.002), stronger in males (β = -0.0024; 95% CI: -0.0038, -0.0009, p = 0.003) than in females (β = -0.0009; 95% CI: -0.0020, 0.0003, p = 0.1). Elevated mean childhood blood lead concentration was also associated with a significant decrease in IGF2/H19 (β = -0.0013; 95% CI: -0.0023, -0.0003, p = 0.01) DMR methylation, but primarily in females, (β = -0.0017; 95% CI: -0.0029, -0.0006, p = 0.005) rather than in males, (β = -0.0004; 95% CI: -0.0023, 0.0015, p = 0.7). Elevated blood lead concentration during the neonatal period was associated with higher PLAGL1/HYMAI DMR methylation regardless of sex (β = 0.0075; 95% CI: 0.0018, 0.0132, p = 0.01). The magnitude of associations between cumulative lead exposure and CpG methylation remained unaltered from 30 to 78 months.

CONCLUSIONS

Our findings provide evidence that early childhood lead exposure results in sex-dependent and gene-specific DNA methylation differences in the DMRs of PEG3, IGF2/H19, and PLAGL1/HYMAI in adulthood.

CITATION

Li Y, Xie C, Murphy SK, Skaar D, Nye M, Vidal AC, Cecil KM, Dietrich KN, Puga A, Jirtle RL, Hoyo C. 2016. Lead exposure during early human development and DNA methylation of imprinted gene regulatory elements in adulthood. Environ Health Perspect 124:666-673; http://dx.doi.org/10.1289/ehp.1408577.

Detectable Blood Lead Level and Body Size in Early Childhood

Rates of childhood obesity have risen at the same time rates of high blood lead levels (BLLs) have fallen. Recent studies suggest that higher BLL is inversely associated with body size in older children (ages 3-19 years). No contemporaneous studies have examined if having a detectable BLL is associated with body size in very early childhood. We examined if detectable BLL is associated with body size in early childhood. A total of 299 birth cohort participants completed a study visit at ages 2-3 years with weight and height measurements; prior to this clinic visit, a BLL was drawn as part of routine clinical care. Body mass index (BMI) percentile and Z-score were calculated; children with BMI ≥85th percentile were considered overweight/obese at age of 2 years. Detectable BLL was defined as BLL ≥1 μg/dL. A total of 131 (43.8 %) children had a detectable BLL measured at mean aged 15.4 ± 5.5 months. Mean age at body size assessment was 2.2 ± 0.3 years (53.2 % male, 68.6 % African-American). After adjusting for race, sex, and birth weight, children with a detectable BLL had a 43 % lower risk of BMI ≥85th percentile (P = 0.041) and a 0.35-unit lower BMI Z-score (P = 0.008) compared to children without a detectable BLL. Neither race nor sex modified this association (all interactions P > 0.21). Consistent with recent studies in older children, having a detectable BLL was associated with smaller body size at ages 2-3 years. Additional research on the mechanism of this association is needed but may include mechanisms of appetite suppression via lead.

Validation and Assessment of Pediatric Lead Screener Questions for Primary Prevention of Lead Exposure

OBJECTIVE

Pediatric lead screener questions have previously been evaluated for their ability to identify children whose blood lead levels (BLLs) are greater than 10 µg/dL. Based on recent policy changes stressing that there is no safe BLL for children, the current study reevaluates the screener questions for their ability to identify children with BLLs less than 2 µg/dL and the validity of the questions in positively identifying those at greater risk for exposure.

METHOD

A total of 202 parents of children enrolled in Head Start programs were administered the pediatric lead screener, questions to validate the screener questions, and children's BLLs were collected in Summer 2013. Pediatric screener questions were validated against children's BLL and the more comprehensive questions on lead risk.

RESULTS

In predicting BLL greater than 2 µg/dL, the pediatrician screener tool had a sensitivity of 26.3% and specificity of 72.2%. Each of the screener questions had low sensitivities for identifying children with BLLs above 2 µg/dL. The screener questions did not demonstrate adequate validity when compared against a more comprehensive battery of lead exposure risk indicators. The validation questions improved sensitivity to detect children with BLL >2 µg/dL and reduced the number of false positives.

CONCLUSION

The pediatrician screener questions in their current format are not a useful primary prevention tool in identifying children at greater risk for lead exposure and in need of secondary prevention through the receipt of a blood lead test. A revision to the protocol for identifying children at risk could result in better primary and secondary prevention efforts.

Low Levels of Awareness of Lead Hazards among Pregnant Women in a High Risk--Johannesburg Neighbourhood

Background: The widespread use of lead and elevated risk of lead exposure in South African children justifies a need for high levels of awareness of the sources, exposure pathways, and measures to reduce this risk in children. This study aimed to determine the levels of knowledge of lead hazards among pregnant women in an area where children had already been established to be at a high risk of lead exposure and poisoning. Methods: Following informed consent, a structured questionnaire was administered to 119 pregnant women attending antenatal clinic services at Rahima Moosa Mother and Child Hospital, west of central Johannesburg. Questions were asked about social, demographic and residential characteristics, as well as knowledge, perceptions, behaviours and practices in relation to child lead hazards. Conclusion: Overall awareness of the dangers of lead in pregnancy was low (11%). Amongst those who had heard of it, only 15% thought that lead could cause detrimental health effects. A consequence of this low level of awareness of lead hazards is a high potential for the participants and their children to unwittingly be exposed to environmental lead from various sources, thereby undermining preventative approaches.

Blood Lead Levels in Andean Infants and Young Children in Ecuador: An International Comparison

Lead (Pb) exposure in infants and children remains an international health concern. Blood lead (PbB) levels of a cohort of 130 Ecuadorian infants and young children aged 0.33 to 5.8 yr were compared to values reported for similar age groups in Africa, Asia, Europe, Latin America, and the United States. The mean PbB level for the total group of 130 Ecuadorian infants and young children in this study was 29.4 μg/dl (SD: 24.3; range: 3.0-128.2; median: 21.7; geometric mean: 20.7 μg/dl). The mean PbB level for the 0-2 yr age group (infants) was 33.6 μg/dl (SD: 28.9; median: 22.0; range: 3.9-119.7; geometric mean: 23.6 μg/dl), while the average PbB level for the 3-5 yr age group (young children) was 27.9 μg/dl (SD: 22.5: median: 22; range: 3-128.2; geometric mean: 19.8 μg/dl). The difference between the mean PbB levels for the infants and young children was not statistically significant. The average PbB level of 32.6 μg/dl for males was not statistically different from the mean PbB level of 26.3 μg/dl for females. The PbB levels observed in Ecuadorian infants and young children in this investigation were elevated above the World Health Organization (WHO) level of concern of 10 μg/dl and Centers for Disease Control and Prevention (CDC) current reference value of 5 μg/dl. Values were comparable to concentrations found in Pakistan, where occupational use of Pb is prevalent. These findings further indicate that infants and young children exposed to Pb from Pb glazing of ceramics in Andean Ecuadorian villages exhibit greater potential metal-mediated poisoning than children of similar ages in Asia, Europe, other Latin American countries, and the United States.

Fetal exposure to environmental neurotoxins in Taiwan

Mercury (Hg), lead (Pb), cadmium (Cd), and arsenic (As) are recognized neurotoxins in children that particularly affect neurodevelopment and intellectual performance. Based on the hypothesis that the fetal basis of adult disease is fetal toxic exposure that results in adverse outcomes in adulthood, we explored the concentrations of key neurotoxins (i.e., Hg, Pb, Cd, and As) in meconium to identify the risk factors associated with these concentrations. From January 2007 to December 2009, 545 mother-infant pairs were recruited. The geometric mean concentrations of Pb and As in the meconium of babies of foreign-born mothers (22.9 and 38.1 µg/kg dry weight, respectively) were significantly greater than those of babies of Taiwan-born mothers (17.5 and 33.0 µg/kg dry weight, respectively). Maternal age (≥30 y), maternal education, use of traditional Chinese herbs during pregnancy, and fish cutlet consumption (≥3 meals/wk) were risk factors associated with concentrations of key prenatal neurotoxins. The Taiwan government should focus more attention on providing intervention programs for immigrant mothers to help protect the health of unborn babies. Further investigation on how multiple neurotoxins influence prenatal neurodevelopment is warranted.

Blood lead levels and associated factors among children in Guiyu of China: a population-based study

OBJECTIVES

Children's health problems caused by the electronic waste (e-waste) lead exposure in China remains. To assess children's blood lead levels (BLLs) in Guiyu of China and investigate risk factors of children's elevated BLLs in Guiyu.

MATERIAL AND METHODS

842 children under 11 years of age from Guiyu and Haojiang were enrolled in this population-based study during 2011-2013. Participants completed a lifestyle and residential environment questionnaire and their physical growth indices were measured, and blood samples taken. Blood samples were tested to assess BLLs. Children's BLLs between the two groups were compared and factors associated with elevated BLLs among Guiyu children were analyzed by group Lasso logistic regression model.

RESULTS

Children living in Guiyu had significant higher BLLs (7.06 µg/dL) than the quantity (5.89 µg/dL) of Haojiang children (P<0.05). Subgroup analyses of BLLs exceeding 10 µg/dL showed the proportion (24.80%) of high-level BLLs for Guiyu children was greater than that (12.84%) in Haojiang (P<0.05). Boys had greater BLLs than girls, irrespectively of areas (P<0.05). The number of e-waste piles or recycling workshops around the house (odds ratio, 2.28; 95% confidence interval [CI], 1.37 to 3.87) significantly contributed to the elevated BLLs of children in Guiyu, and girls had less risk (odds ratio, 0.51; 95% CI, 0.31 to 0.83) of e-waste lead exposure than boys.

CONCLUSIONS

This analysis reinforces the importance of shifting e-waste recycling piles or workshops to non-populated areas as part of a comprehensive response to e-waste lead exposure control in Guiyu. To correct the problem of lead poisoning in children in Guiyu should be a long-term mission.

Pathways of Pb and Mn observed in a 5-year longitudinal investigation in young children and environmental measures from an urban setting

We monitored 108 children ≤5 years on a 6-month basis for up to 5 years in a major urban setting. Samples (n ∼ 7000) included blood, urine, handwipes (interior, and after exterior playing), 6-day duplicate diet, drinking water, interior house and day care dust-fall accumulation using petri dishes, exterior dust-fall accumulation, exterior dust sweepings, paint, soil and urban air. The geometric mean blood Pb (PbB) was 2.1 μg/dL and blood Mn (MnB) was 10.0 μg/L. Following a path modelling approach, mixed model analyses for a fully adjusted model showed the strongest associations for PbB were with interior house dust and soil; for MnB there were no significant associations with any predictors. Predictor variables only explained 9% of the variance for Pb and 0.7% for Mn. Relationships between environmental measures and PbB in children are not straightforward; soil and dust sweepings contribute only about 1/5th of the amounts to PbB found in other studies.

Blood metals concentration in type 1 and type 2 diabetics

Mechanisms for the onset of diabetes and the development of diabetic complications remain under extensive investigations. One of these mechanisms is abnormal homeostasis of metals, as either deficiency or excess of metals, can contribute to certain diabetic outcomes. Therefore, this paper will report the blood levels of chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), mercury (Hg), nickel (Ni), lead (Pb), selenium (Se), and zinc (Zn) in subjects with type 1 diabetes (n = 192, mean age 48.8 years, mean disease duration 20.6 years), type 2 diabetes (n = 68, mean age 68.4 years, mean disease duration 10.2 years), and in control subjects (n = 59, mean age 57.2 years), and discuss the results indicating their possible role in diabetes. The metal concentrations were measured by sector field inductively coupled plasma mass spectrometry after microwave-induced acid digestion of blood samples. The accuracy was checked using a blood-based certified reference material, and recoveries of all elements were in the range of 92-101 % of certified values. Type 1 diabetes was found to be associated with Cr (p = 0.02), Mn (p < 0.001), Ni (p < 0.001), Pb (p = 0.02), and Zn (p < 0.001) deficiency, and type 2 diabetes with Cr (p = 0.014), Mn (p < 0.001), and Ni (p < 0.001) deficiency. These deficiencies were appreciated also subdividing the understudied patients for gender and age groups. Furthermore, in type 1 diabetes, there was a positive correlation between Pb and age (p < 0.001, ρ = 0.400) and Pb and BMI (p < 0.001, ρ = 0.309), while a negative correlation between Fe and age (p = 0.002, ρ = -0.218). In type 2 diabetes, there was a negative correlation between Fe and age (p = 0.017, ρ = -0.294) and Fe and BMI (p = 0.026, ρ = -0.301). Thus, these elements may play a role in both forms of diabetes and combined mineral supplementations could have beneficial effects.

Assessment of infantile mineral imbalances in autism spectrum disorders (ASDs)

The interactions between genes and the environment are now regarded as the most probable explanation for autism. In this review, we summarize the results of a metallomics study in which scalp hair concentrations of 26 trace elements were examined for 1,967 autistic children (1,553 males and 414 females aged 0-15 years-old), and discuss recent advances in our understanding of epigenetic roles of infantile mineral imbalances in the pathogenesis of autism. In the 1,967 subjects, 584 (29.7%) and 347 (17.6%) were found deficient in zinc and magnesium, respectively, and the incidence rate of zinc deficiency was estimated at 43.5% in male and 52.5% in female infantile subjects aged 0-3 years-old. In contrast, 339 (17.2%), 168 (8.5%) and 94 (4.8%) individuals were found to suffer from high burdens of aluminum, cadmium and lead, respectively, and 2.8% or less from mercury and arsenic. High toxic metal burdens were more frequently observed in the infants aged 0-3 years-old, whose incidence rates were 20.6%, 12.1%, 7.5%, 3.2% and 2.3% for aluminum, cadmium, lead, arsenic and mercury, respectively. These findings suggest that infantile zinc- and magnesium-deficiency and/or toxic metal burdens may be critical and induce epigenetic alterations in the genes and genetic regulation mechanisms of neurodevelopment in the autistic children, and demonstrate that a time factor "infantile window" is also critical for neurodevelopment and probably for therapy. Thus, early metallomics analysis may lead to early screening/estimation and treatment/prevention for the autistic neurodevelopment disorders.

The utility and financial implications of obtaining routine lead levels for child psychiatric inpatients

This study attempted to challenge the CDC recommendations regarding routine screening blood lead levels in children. The purpose was to determine the efficacy of obtaining routine lead levels on all patients admitted to a child psychiatric inpatient unit. A retrospective chart review of children admitted to a psychiatric inpatient unit during a 12 month period. The audit determined average lead levels and costs associated with the screening program. 1 of 61 admitted children was found to have an elevated lead level. Number needed to treat was determined to be 98. The cost per case detected was determined to be over $8,600. Routine screening for blood lead levels in all children admitted to a psychiatric inpatient unit does not appear efficacious or cost effective.

Philadelphia's Lead Court is making a difference

The Philadelphia Lead Court (PLC) was created as an innovative law enforcement strategy to compel property owners to comply with city health codes to remediate their properties of lead hazards, which had led to elevated blood lead levels and lead poisoning in resident children. This study presents a detailed account of and analyzes the opinions of fifteen key informants drawn from the Philadelphia health and law departments and judicial system that staff and run the PLC in response to a fifteen-question structured survey. Main themes reviewed include the effectiveness of the PLC as compared with precourt law enforcement strategies and within the context of a specialized court, the use of fines, the impact of grant funding for remediation work, the major advantages and disadvantages of the PLC, and suggested changes to improve court function, followed by key recommendations. The article concludes that our informants found that the PLC has been very effective and successful. This model could be replicated by other cities with similar health code enforcement challenges.