Children drinking private well water have higher blood lead than those with city water.

Although the Flint, Michigan, water crisis renewed concerns about lead (Pb) in city drinking water, little attention has been paid to Pb in private wells, which provide drinking water for 13% of the US population. This study evaluates the risk of Pb exposure in children in households relying on private wells. It is based on a curated dataset of blood Pb records from 59,483 North Carolina children matched with household water source information. We analyze the dataset for statistical associations between children's blood Pb and household drinking water source. The analysis shows that children in homes relying on private wells have 25% increased odds (95% CI 6.2 to 48%, P < 0.01) of elevated blood Pb, compared with children in houses served by a community water system that is regulated under the Safe Drinking Water Act. This increased Pb exposure is likely a result of corrosion of household plumbing and well components, because homes relying on private wells rarely treat their water to prevent corrosion. In contrast, corrosion control is required in regulated community water systems. These findings highlight the need for targeted outreach to prevent Pb exposure for the 42.5 million Americans depending on private wells for their drinking water.

Investigation of Childhood Lead Poisoning from Parental Take-Home Exposure from an Electronic Scrap Recycling Facility ­ Ohio, 2012.

Lead affects the developing nervous system of children, and no safe blood lead level (BLL) in children has been identified. Elevated BLLs in childhood are associated with hyperactivity, attention problems, conduct problems, and impairment in cognition. Young children are at higher risk for environmental lead exposure from putting their hands or contaminated objects in their mouth. Although deteriorating lead paint in pre-1979 housing is the most common source of lead exposure in children, data indicate that ≥30% of children with elevated BLLs were exposed through a source other than paint. Take-home contamination occurs when lead dust is transferred from the workplace on employees' skin, clothing, shoes, and other personal items to their car and home. Recycling of used electronics (e-scrap) is a relatively recent source of exposure to developmental neurotoxicants, including lead. In 2010, the Cincinnati Health Department and Cincinnati Children's Hospital Pediatric Environmental Health Specialty Unit (PEHSU) investigated two cases of childhood lead poisoning in a single family. In 2012, CDC's National Institute for Occupational Safety and Health (NIOSH) learned about the lead poisonings during an evaluation of the e-scrap recycling facility where the father of the two children with lead poisoning worked. This report summarizes the case investigation. Pediatricians should ask about parents' occupations and hobbies that might involve lead when evaluating elevated BLLs in children, in routine lead screening questionnaires, and in evaluating children with signs or symptoms of lead exposure.

Childhood lead exposure in an industrial town in China: coupling stable isotope ratios with bioaccessible lead.

Fingerprinting based on stable isotopes of lead (Pb) in blood and environmental media helps to identify Pb exposure pathways in children. However, previous studies used stable isotopes of total Pb in media. In this study, a wire rope production town in China (Zhuhang) was selected for investigating the effectiveness of using isotope ratios in bioaccessible Pb to identify childhood Pb exposure pathways. Blood Pb levels of 115 children in Zhuhang were 1.7-20.4 µg dL(-1), averaging 6.1 ± 3.2 µg dL(-1) (mean ± standard deviation), and were ∼1.6 times the national average in China (3.9 ± 1.8 µg dL(-1)). Among different environmental media (housedust, soil, PM10, vegetables, rice, and drinking water), housedust (695 ± 495 mg kg(-1)) and vegetables [0.36 ± 0.40 mg (kg of fresh weight)(-1)] contained elevated Pb concentrations. The isotope ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) of total Pb were the highest in housedust (0.8587 ± 0.0039 and 2.1049 ± 0.0087) but lower than blood Pb ratios (0.8634 ± 0.0027 and 2.1244 ± 0.0061). When using bioaccessible Pb in housedust (0.8639 ± 0.0018 and 2.1171 ± 0.0036), the isotope ratios overlapped with blood Pb ratios, suggesting that incidental ingestion of housedust was the predominant contributor to children's blood Pb. Coupling the stable isotope technique with bioaccessible Pb is more reliable for identifying Pb exposure pathways than total Pb determinations.

Occupational and environmental lead exposure to adolescent workers in battery recycling workshops.

Lead (Pb), as other environmental neurotoxicant substances, has the capability to interfere with many biochemical events present in cells throughout the body. In the present study, the environmental and occupational exposure to Pb has been assessed by analyzing the scalp hair samples of male adolescents aged 12-15 years, who have worked for the last 12-36 months in Pb battery recycling workshops (BRWs). For comparative purposes, gender and age-matched subjects living in the vicinity of recycling workshops as well as in areas without industrial activity were used as controls. The scalp hair samples were oxidized by acid in a microwave oven prior to determination of Pb by electrothermal atomic absorption spectrometry. The results indicated that both workers and nonworking exposed subjects had higher levels of Pb than nonexposed controls. The contents of Pb in scalp hair of adolescent workers in the present study were compared with those reported in other studies.

Early childhood lead exposure and academic achievement: evidence from Detroit public schools, 2008-2010.

OBJECTIVES: We assessed the long-term effect of early childhood lead exposure on academic achievement in mathematics, science, and reading among elementary and junior high school children. METHODS: We linked early childhood blood lead testing surveillance data from the Detroit Department of Health and Wellness Promotion to educational testing data from the Detroit, Michigan, public schools. We used the linked data to investigate the effect of early childhood lead exposure on academic achievement among school-aged children, both marginally and adjusted for grade level, gender, race, language, maternal education, and socioeconomic status. RESULTS: High blood lead levels before age 6 years were strongly associated with poor academic achievement in grades 3, 5, and 8. The odds of scoring less than proficient for those whose blood lead levels were greater than 10 micrograms per deciliter were more than twice the odds for those whose blood lead levels were less than 1 micrograms per deciliter after adjustment for potential confounders. CONCLUSIONS: Early childhood lead exposure was negatively associated with academic achievement in elementary and junior high school, after adjusting for key potential confounders. The control of lead poisoning should focus on primary prevention of lead exposure in children and development of special education programs for students with lead poisoning.

Environmental lead exposure and otoacoustic emissions in Andean children.

Studies relating sensory hearing impairment to lead (Pb) exposure in children have presented inconsistent results. The objective of this study was to measure distortion product otoacoustic emissions (DPOAE), sounds emanating from the outer hair cells of the inner ear, in Pb-exposed children to determine the effects of Pb poisoning on the inner ear. DPOAE were recorded for 9 f(2) frequencies from 1187 to 7625 Hz on 102 ears of 53 Pb-exposed children (aged 6-16 yr) residing in Pb-contaminated environments in the Andes Mountains of Ecuador where Pb glazing of ceramics is the primary livelihood. Blood lead (PbB) levels ranged from 4.2 to 94.3 µg/dl (mean: 37.7; SD: 25.7; median: 36.4). The median PbB level was markedly higher than the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) 10-µg/dl action level. Spearman rho correlation analyses of the relation between PbB level and DPOAE amplitude and between PbB level and DPOAE signal-to-noise ratio revealed no significant associations at any of the f(2) frequencies tested. In addition, no significant correlation (Spearman rho) between PbB level and hearing sensitivity for 6 pure-tone test frequencies from 1000 to 8000 Hz was found. Although the study group was found to have abnormally elevated PbB levels, in contrast to some earlier reports, the results of the current study showed no consistent Pb-induced sensory effects on the cochlea of Pb-intoxicated children.

Blood lead levels in Egyptian children from high and low lead-polluted areas: impact on cognitive function.

OBJECTIVES: Many children are harmed by low-level lead exposure which impairs cognitive development with subsequent poor scholastic achievement. We investigated blood lead levels in children in relation to cognitive function. MATERIALS AND METHODS: Blood lead levels were measured in 100 children recruited from high (n = 50) and low (n = 50) lead-polluted areas. RESULTS: Blood lead levels ranged between 3 and 28 microg/dl (median 9, interquartile range 6 microg/dl). In addition, 43% of children had levels > or =10 microg/dl, of whom 90.1% were living in high-risk areas for lead pollution. Cognitive dysfunction was found in 37% of children. Children with cognitive dysfunction had significantly higher blood lead and lower hemoglobin than those without (P < 0.001). CONCLUSIONS: Increased blood lead level in many children is one of the health problems in Egypt which may be the reason, at least in part, for cognitive dysfunction with subsequent poor scholastic achievement. Thus, interventions to control lead exposure are mandatory.

Reduced regional volumes associated with total psychopathy scores in an adult population with childhood lead exposure.

Childhood lead exposure has been correlated to acts of delinquency and criminal behavior; however, little research has been conducted to examine its potential long term influence on behavioral factors such as personality, specifically psychopathic personality. Neuroimaging studies have demonstrated that the effects of childhood lead exposure persist into adulthood, with structural abnormalities found in gray and white matter regions involved in behavioral decision making. The current study examined whether measurements of adult psychopathy were associated with neuroanatomical differences in structural brain volumes for a longitudinal cohort with measured childhood lead exposure. We hypothesized that increased total psychopathy scores and increased blood lead concentration at 78 months of age (PbB78) would be inversely associated with volumetric measures of gray and white matter brain structures responsible for executive and emotional processing. Analyses did not display a direct effect between total psychopathy score and gray matter volume; however, reduced white matter volume in the cerebellum and brain stem in relation to increased total psychopathy scores was observed. An interaction between sex and total psychopathy score was also detected. Females displayed increased gray matter volume in the frontal, temporal, and parietal lobes associated with increased total psychopathy score, but did not display any white matter volume differences. Males primarily displayed reductions in frontal gray and white matter brain volume in relation to increased total psychopathy scores. Additionally, reduced gray and white matter volume was associated with increased blood lead levels in the frontal lobes; reduced white matter volume was also observed in the parietal and temporal lobes. Females demonstrated gray and white matter volume loss associated with increased PbB78 values in the right temporal lobe, as well as reduced gray matter volume in the frontal lobe. Males displayed reduced white matter volumes associated with increased PbB78 values in the frontal, temporal, and parietal lobes. Comparison of the two primary models revealed a volumetric decrease in the white matter of the left prefrontal cortex associated with increased total psychopathy scores and increased blood lead concentration in males. The results of this study suggested that increased psychopathy scores in this cohort may be attributable to the neuroanatomical abnormalities observed and that childhood lead exposure may be influential to these outcomes.

[Intelligence quotient loss in Mexican pottery artisan's children]. / Pérdida de coeficiente intelectual en hijos de alfareros mexicanos.

BACKGROUND: In Mexico, artisans frequently use lead oxide or greta in order to produce utensils, which are destined to preparation and storage of food and drinks. Additionally, the risk of lead poisoning of artisans and their families is greater than in general population, and within these families, children are the most susceptible to lead poisoning. The aim of this study was to estimate IQ loss in Mexican children from potter families exposed to lead. METHODS: Lead concentrations in soil were determined in 19 potter's homes that functioned as pottery workshops in seven Mexican states between 2009 and 2012. This information was used to estimate blood lead levels through the integrated exposure uptake biokinetic (IEUBK) model. The loss of IQ points was then estimated according to the Lanphear and Schwartz models. RESULTS: The mean lead concentration found in the workshops' soil was 1098.4 ppm. Blood lead levels estimated in children under 8 years old were 26.4 µg/dL and the loss of IQ points comprised from 7.13 to 8.84 points depending on the model. CONCLUSIONS: It is possible that 11 children from families of artisans in Mexico may be losing between 7.13 to 8.84 IQ points, due to lead exposure in their houses-workshops. This loss in IQ points could have important health, economic and social impacts.

Introducción: en México, los alfareros continúan usando frecuentemente el óxido de plomo o greta para producir utensilios, los cuales se destinan a la preparación y almacenamiento de alimentos y bebidas. Adicionalmente, el riesgo de intoxicación por plomo de los alfareros y sus familias es mayor que en la población general, y en tales familias, los niños son los más susceptibles a la intoxicación por plomo. El objetivo del estudio fue estimar la pérdida de puntos de coeficiente intelectual (CI) en hijos de alfareros mexicanos expuestos al plomo. Métodos: durante el periodo de 2009 a 2012 se determinaron las concentraciones de plomo en suelo de 19 casas-talleres de alfareros en siete estados mexicanos. Esta información se utilizó para estimar el nivel de plomo en sangre, por medio del modelo biocinético integrado de absorción por exposición (IEUBK, por sus siglas en inglés). Posteriormente, se calcularon los puntos perdidos de CI según los modelos de Schwartz y Lanphear. Resultados: la concentración promedio de plomo en suelo fue de 1098.4 ppm. Se estimó un nivel de plomo en sangre de 26.4 µg/dL para menores de 8 años. La pérdida de puntos de CI estimada fue 7.13 y 8.84, según el modelo utilizado. Conclusión: es posible que al menos 11 niños de familias alfareras mexicanas estén perdiendo entre 7.13 y 8.84 puntos de CI, debido a la exposición al plomo en sus casas-talleres, lo que supone importantes impactos económicos, sociales y de salud.

Lead neurotoxicity in children: is prenatal exposure more important than postnatal exposure?

Numerous studies indicate that low-level lead poisoning causes mild mental retardation and low IQ scores in children. The general mean lead intake in the adult European population corresponds to a reassuring 14% (0.5-56%) of the tolerable daily intake: at this low level of exposure only few children (less than 10%) have blood lead levels (PbB) higher than 10 microg/dl, previously considered the PbB of concern. In more recent years data now suggest that even when 'the lifetime average blood lead concentration' is below 10 microg/dl an inverse association exists with intelligence quotient (IQ) scores. Two-thirds (45-75%) of lead in blood, however, comes from long-term tissue stores and this is especially true for newborn infants and pregnant women. Several data suggest that for lead the main toxic event is prenatal exposure: therefore we should focus our attention on maternal lead stores and whenever possible avoid their mobilization during pregnancy. In this regard we should design appropriate studies to confirm whether dietary supplementations can reduce bone resorption and lead mobilization during pregnancy. The hypothesis that the amount of maternal bone lead stores is the relevant parameter for predicting the level of neurotoxicity of this metal gives some optimism for the future: if we study children whose mothers never underwent high environmental pollution (born after the withdrawal of lead from gasoline) and hence have relatively low bone lead stores we could find that, at the population level, lead has little influence on children IQ scores.

Environmental and Occupational Lead Exposure Among Children in Cairo, Egypt: A Community-Based Cross-Sectional Study.

The aim of this study was to assess childhood lead exposure in a representative sample of Cairo, and to investigate the possible risk factors and sources of exposure. This cross-sectional study was conducted from November 2014 through April 2015. The target population was children aged 6 to 18 years, recruited into 4 groups, garbage city, moderate-living standard area, urban and suburban schools, and workshops in the city of Cairo. Blood lead levels (BLLs) and hemoglobin (Hb) concentrations were measured. Also, potential local environmental sources were assessed for hazardous lead contamination. Analysis on 400 participants has been carried out. A total of 113 children had BLLs in the range 10 to 20 µg/dL. Smoking fathers, housing conditions, playing outdoors, and exposure to lead in residential areas were significantly correlated with high BLLs. The mean values of hemoglobin were inversely correlated with BLLs. Children involved in pottery workshops had the highest BLLs and the lowest Hb values with a mean of (43.3 µg/dL and 8.6 g/dL, respectively). The mean value of environmental lead in workshop areas exceeded the recommended levels. Also, those values measured in dust and paint samples of garbage city were significantly high. Moreover, the mean lead levels in the soil samples were significantly higher in urban schools (P = 0.03) than the suburban ones. Childhood lead poisoning accounts for a substantial burden in Egypt, which could be preventable. Development of national prevention programs including universal screening program should be designed to reduce incidence of lead toxicity among children.

Bone lead levels and language processing performance.

The relation between bone lead absorption and language processing abilities in 156 randomly selected 11- to 14-year-old boys who were asymptomatic for lead toxicity is examined. Tibial lead concentrations were measured by X-ray fluorescence spectroscopy. The language processing outcome variables consisted of the least and most difficult subtests from the Nonword Repetition Task, Competing Language Processing Task, and the Revised Token Test. Participants were classified by quartiles according to bone lead concentrations, and analysis of variance and analysis of covariance measured the impact on language processing scores. Results showed that children in the highest bone lead quartile displayed decreased language processing performance on the most difficult language processing tasks but not on the easier tasks.

Effect modification in epidemiologic studies of low-level neurotoxicant exposures and health outcomes.

Little attention has been invested in exploring the possibility that the nature or magnitude of a neurotoxicant's health impact on children depends on host characteristics (e.g., sex, age) or contextual factors (e.g., socioeconomic status, other chemical exposures). Such effect modification is a property of a true association, and should be distinguished from confounding. In epidemiologic studies of children, most efforts to identify effect modification have been unsystematic, pursued as part of data analysis rather than of study design. As a result, most samples have insufficient statistical power to characterize effect modification with adequate precision. This may contribute to an inconsistency in results across studies. Failure to assess effect modification adequately may also lead to invalid inferences. If the magnitude of an association between a neurotoxicant exposure and a particular end point varies across strata of a third factor, an estimate that summarizes the association across strata of this factor will be inappropriate, overestimating the association in a stratum in which the association is absent, and underestimating it in a stratum in which it is present. Until such dependencies are identified, our understanding of the mechanism(s) of a compound's neurotoxicity will remain incomplete, as will the knowledge base required to formulate public policy that adequately protects the most sensitive subgroups of the population.

Bone lead levels in adjudicated delinquents. A case control study.

BACKGROUND: Lead exposure shares many risk factors with delinquent behavior, and bone lead levels are related to self-reports of delinquent acts. No data exist as to whether lead exposure is higher in arrested delinquents. The goal of this study is to evaluate the association between lead exposure, as reflected in bone lead levels, and adjudicated delinquency. METHODS: This is a case-control study of 194 youths aged 12-18, arrested and adjudicated as delinquent by the Juvenile Court of Allegheny County, PA and 146 nondelinquent controls from high schools in the city of Pittsburgh. Bone lead was measured by K-line X-ray fluorescence (XRF) spectroscopy of tibia. Logistic regression was used to model the association between delinquent status and bone lead concentration. Covariates entered into the model were race, parent education and occupation, presence of two parental figures in the home, number of children in the home and neighborhood crime rate. Separate regression analyses were also conducted after stratification on race. RESULTS: Cases had significantly higher mean concentrations of lead in their bones than controls (11.0+/-32.7 vs. 1.5+/-32.1 ppm). This was true for both Whites and African Americans. The unadjusted odds ratio for a lead level > or =25 vs. <25 ppm was 1.9 (95% CL: 1.1-3.2). After adjustment for covariates and interactions and removal of noninfluential covariates, adjudicated delinquents were four times more likely to have bone lead concentrations >25 ppm than controls (OR=4.0, 95% CL: 1.4-11.1). CONCLUSION: Elevated body lead burdens, measured by bone lead concentrations, are associated with elevated risk for adjudicated delinquency.

Children in Illinois with elevated blood lead levels, 1993-1998, and lead-related pediatric hospital admissions in Illinois, 1993-1997.

OBJECTIVE: This study uses screening and hospitalization data to describe the prevalence of childhood lead poisoning in Chicago and the rest of the state of Illinois. METHODS: The authors used aggregate data published by the Illinois Department of Public Health on blood lead testing of children ages 0-6 years and data on lead-related hospital admissions of children ages 0-6 years, drawn from an administrative dataset compiled as part of a state initiative. RESULTS: No clear time trends in the percentage of children with elevated blood lead levels (defined as >15 micrograms per deciliter [microg/dL] or >45 microg/dL) were evident in either Chicago or the rest of Illinois. The proportions of children with elevated blood lead levels in Chicago and in the rest of Illinois did not decline at the dramatic rate seen in the US as a whole during the 1990s. Over a five-year period, in-hospital charges of $7.7 million were generated for the care of lead-poisoned children ages 6-16 in Chicago alone. CONCLUSION: Surveillance data, analyzed at the appropriate geographic level, can be used to focus resources on high-risk areas and to evaluate prevention efforts.

Cognitive deficits associated with blood lead concentrations <10 microg/dL in US children and adolescents.

OBJECTIVE: Lead is a confirmed neurotoxicant, but the lowest blood lead concentration associated with deficits in cognitive functioning and academic achievement is poorly defined. The purpose of the present study was to examine the relationship of relatively low blood lead concentrations-especially concentrations <10 micrograms per deciliter (microg/dL)--with performance on tests of cognitive functioning in a representative sample of US children and adolescents. METHODS: The authors used data from the Third National Health and Nutrition Examination Survey (NHANES III), conducted from 1988 to 1994, to assess the relationship between blood lead concentration and performance on tests of arithmetic skills, reading skills, nonverbal reasoning, and short-term memory among 4,853 children ages 6-16 years. RESULTS: The geometric mean blood lead concentration for children n the study sample was 1.9 microg/dL; 172 (2.1%) had blood lead concentrations > or =10 microg/dL. After adjustment for gender, race/ethnicity, poverty, region of the country, parent or caregiver's educational level, parent or caregiver's marital status parent, serum ferritin level, and serum cotinine level, the data showed an inverse relationship between blood lead concentration and scores on four measures of cognitive functioning. For every 1 microg/dL increase in blood lead concentration, there was a 0.7-point decrement in mean arithmetic scores, an approximately 1-point decrement in mean reading scores, a 0.1-point decrement in mean scores on a measure of nonverbal reasoning, and a 0.5-point decrement in mean scores on a measure of short-term memory. An inverse relationship between blood lead concentration and arithmetic and reading scores was observed for children with blood lead concentrations lower than 5.0 microg/dL. CONCLUSION: Deficits in cognitive and academic skills associated with lead exposure occur at blood lead concentrations lower than 5 microg/dL.