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Rouzi L, El-Hamri H, Cherkani-Hassani A, Benbounou N, El Kari K, Bouhya S, Aguenaou H, Jouhadi Z, Fekhaoui M. Lead in umbilical cord blood and associated factors in Casablanca Morocco: A preliminary results. J Trace Elem Med Biol 2024; 85:127494. [PMID: 39024849 DOI: 10.1016/j.jtemb.2024.127494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 06/28/2024] [Accepted: 07/02/2024] [Indexed: 07/20/2024]
Abstract
BACKGROUND Lead is the most common toxic metal to which Moroccans are exposed. Given the susceptibility of the fetus to lead, it is crucial to assess prenatal lead exposure. However, in Morocco, no study has assessed prenatal exposure to lead. The main goals of the present study are to determine lead concentration in umbilical cord blood and identify risk factors for prenatal lead exposure in Casablanca, Morocco. METHODS To achieve these purposes, 87 cord blood lead samples were collected from mothers-baby pairs from January to December 2019. Indeed, a structured questionnaire was used to collect socio-demographic characteristics, obstetric data, leisure, cultural habits, and environmental information. Cord blood lead level was analyzed by inductively coupled plasma-mass spectrometry. RESULTS The median lead concentration was 4.902 µg/dl with a minimum and maximum of 0.833 µg/dl and 23.593 µg/dl, respectively. A high proportion of the newborns (65.52 %) had cord blood lead levels above the Centers for Disease Control (CDC) allowable threshold limit (3.5 µg/dl). Statistical analysis was performed to assess the association between blood levels and the above factors. Lead levels in cord blood were significantly associated with the maternal educational level, anemia history, delivery mode, passive smoking during pregnancy as well as with the frequency of consumption of tea. CONCLUSION This study provides the first data on lead levels in newborns. Cord blood lead levels were high in the majority of the participants, these results reinforce the need to establish health surveillance programs in Morocco.
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Affiliation(s)
- Latifa Rouzi
- Department of Zoology and Animal Ecology, Scientific Institute, Mohammed V University in Rabat, B.P. 1040, Ibn Battuta Av, Rabat 10100, Morocco.
| | | | - Abha Cherkani-Hassani
- Laboratory of Analytical Chemistry, Faculty of Medicine and Pharmacy, Mohammed V University in Rabat, 10100, Morocco
| | - Nadia Benbounou
- Laboratory LIMAT, Hassan II University, B.P 7955, Casablanca, Morocco; The Multi laboratory LC2A, N°182, Industrial Zone Mohammedia, Morocco
| | | | - Said Bouhya
- Department of Maternity, Children's Ibn Rochd University Hospital, Hassan II University, Casablanca, Morocco
| | - Hassan Aguenaou
- Ibn Tofail University- CNESTEN, Joint, Unit of Nutrition, Health and Environment, Laboratory of Biology and Health, FSK, Regional Designated Center for Nutrition, AFRA/IAEA), Kenitra 14000, Morocco
| | - Zineb Jouhadi
- Department of Pediatric Infectious Diseases, Children's Ibn Rochd University Hospital, Hassan II University, Casablanca, Morocco
| | - Mohammed Fekhaoui
- Department of Zoology and Animal Ecology, Scientific Institute, Mohammed V University in Rabat, B.P. 1040, Ibn Battuta Av, Rabat 10100, Morocco
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He H, Zhang Z, Li M. Association between serum folate concentrations and blood lead levels in adolescents: A cross-sectional study. Front Pediatr 2022; 10:941651. [PMID: 36389396 PMCID: PMC9641282 DOI: 10.3389/fped.2022.941651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 10/05/2022] [Indexed: 11/13/2022] Open
Abstract
As a heavy metal, lead is a common toxic agent. Its accumulation in the body is harmful to physical health, particularly in children and adolescents. Studies have reported that folate may play a protective role in lead exposure. An association between serum folate concentrations (SFC) and blood lead levels (BLL) has been documented in adults, but studies in adolescents are limited. This study investigated the relationship between SFC and BLL in American adolescents. This cross-sectional study collected relevant data on both SFC and BLL of 5,195 adolescents in the NHANES database from 2007 to 2018. Multivariable linear regressions and smooth curve fittings were adopted to evaluate the correlation between BLL and SFC. After adjusting potential confounders, we found negative relationships between BLL and SFC [β = -0.0041 (-0.0063, -0.0019)], and the associations were significant in non-Hispanic Whites, Mexican Americans, and other races but not significant in non-Hispanic blacks (P = 0.139). Furthermore, the negative trends were significant in adolescents aged 16-19 years and females aged 12-15 years but insignificant in males aged 12-15 years (P = 0.172). Therefore, these findings provide a basis for future research on the mechanism of folate in regulating blood lead levels.
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Affiliation(s)
- Huan He
- Department of Ultrasound, Xi'an Children's Hospital, Xi'an, China
| | - Zhan Zhang
- Department of Ultrasound, Xi'an Children's Hospital, Xi'an, China
| | - Min Li
- Department of Ultrasound, Xi'an Children's Hospital, Xi'an, China
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Abstract
Millions of Americans now entering midlife and old age were exposed to high levels of lead, a neurotoxin, as children. Evidence from animal-model and human observational studies suggest that childhood lead exposure may raise the risk of adult neurodegenerative disease, particularly dementia, through a variety of possible mechanisms including epigenetic modification, delayed cardiovascular and kidney disease, direct degenerative CNS injury from lead remobilized from bone, and lowered neural and cognitive reserve. Within the next ten years, the generation of children with the highest historical lead exposures, those born in the 1960s, 1970s, and 1980s, will begin to enter the age at which dementia symptoms tend to emerge. Many will also enter the age in which lead stored in the skeleton may be remobilized at greater rates, particularly for women entering menopause and men and women experiencing osteoporosis. Should childhood lead exposure prove pro-degenerative, the next twenty years will provide the last opportunities for possible early intervention to forestall greater degenerative disease burden across the aging lead-exposed population. More evidence is needed now to characterize the nature and magnitude of the degenerative risks facing adults exposed to lead as children and to identify interventions to limit long-term harm.
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Affiliation(s)
- Aaron Reuben
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
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Perioperative Exposure to Suspect Neurotoxicants From Medical Devices in Newborns With Congenital Heart Defects. Ann Thorac Surg 2018; 107:567-572. [PMID: 30071236 DOI: 10.1016/j.athoracsur.2018.06.035] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/12/2018] [Accepted: 06/15/2018] [Indexed: 11/21/2022]
Abstract
BACKGROUND Industrial chemicals are increasingly recognized as potential developmental neurotoxicants. Di(2-ethylhexyl) phthalate (DEHP), used to impart flexibility and temperature tolerance to polyvinylchloride, and bisphenol A (BPA), used to manufacture polycarbonate, are commonly present in medical devices. The magnitude of exposure in neonates during hospitalization for cardiac operations is unknown. METHODS We quantified urinary concentrations of DEHP metabolites and BPA preoperatively and postoperatively in neonates undergoing cardiac operations and their mothers. Urinary concentrations of these biomarkers reflect recent exposures (half-lives are approximately 6 to 24 hours). Biomarker concentrations in mothers' and infants' preoperative and postoperative samples were compared. RESULTS Operations were performed in 18 infants (mean age, 5 ± 4 [SD] days). The maternal sample was obtained on postpartum day 4 ± 4. The preoperative urine sample was obtained on day-of-life 4 ± 2 and the postoperative sample on day-of-life 6 ± 4. Mean maternal concentrations for DEHP metabolites and BPA were at the 50th percentile for females in the United States general population. Infant preoperative concentrations of 1 DEHP metabolite and BPA were significantly higher than maternal concentrations. Postoperative concentrations for all DEHP metabolites were significantly greater than preoperative concentrations. CONCLUSIONS There is considerable perioperative exposure to DEHP and BPA for neonates undergoing cardiac operations. Infant concentrations for both BPA and DEHP metabolites were significantly higher than maternal concentrations, consistent with the infant's exposure to medical devices. Further study is needed to determine the potential role of these suspect neurotoxicants in the etiology of neurodevelopmental disability after cardiac operations.
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Alvarez-Ortega N, Caballero-Gallardo K, Olivero-Verbel J. Low blood lead levels impair intellectual and hematological function in children from Cartagena, Caribbean coast of Colombia. J Trace Elem Med Biol 2017; 44:233-240. [PMID: 28965581 DOI: 10.1016/j.jtemb.2017.08.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 07/25/2017] [Accepted: 08/07/2017] [Indexed: 02/08/2023]
Abstract
Lead produces numerous biochemical and physiological changes in humans, including hematological disorders, toxic effects on the central nervous system and in the function of several organs. The aim of this study was to determine blood lead levels (BLL) in children from Cartagena, Colombia, associating those with hematological and liver damage markers, the intelligence quotient (IQ), as well as with gene expression of the aminolevulinate dehydratase (ALAD), superoxide dismutase 1 (SOD1), gamma interferon (INF-γ), tumor necrosis factor (TNF) and tumor protein (p53). To achieve this purpose, 118 blood samples were collected from children 5-16 years old, with their respective informed consent from their parents. BLL was measured by atomic absorption; hematological parameters were obtained with automated systems; plasma was utilized to analyze hepatic toxicity markers, alanine aminotransferase (ALT), gamma-glutamyltransferase (γ-GT) and alkaline phosphatase (ALP); the Kaufman Brief Intelligence Test (K-BIT) was administered to measure the IQ; and gene expression was quantified from blood RNA. The mean BLL was 1.7±0.3μg/dL. A low proportion of the children (3.4%) had BLL above the CDC recommended limit (5μg/dL). BLL were correlated weakly, but negatively with child age, weight, height, body mass index, platelets wide distribution, mean platelet volume, γ-GT and IQ. There were not significant changes in the expression of evaluated genes. These results support the hypothesis that BLL below 5μg/dL may still be a detrimental factor on children's cognitive abilities, development and hematology, in line with recent concerns that there is no safe level of pediatric lead exposure.
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Affiliation(s)
- Neda Alvarez-Ortega
- Environmental and Computational Chemistry Group, School of Pharmaceutical Sciences, Zaragocilla Campus, University of Cartagena, Cartagena 130015, Colombia
| | - Karina Caballero-Gallardo
- Environmental and Computational Chemistry Group, School of Pharmaceutical Sciences, Zaragocilla Campus, University of Cartagena, Cartagena 130015, Colombia
| | - Jesus Olivero-Verbel
- Environmental and Computational Chemistry Group, School of Pharmaceutical Sciences, Zaragocilla Campus, University of Cartagena, Cartagena 130015, Colombia.
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Stacy SL, Papandonatos GD, Calafat AM, Chen A, Yolton K, Lanphear BP, Braun JM. Early life bisphenol A exposure and neurobehavior at 8years of age: Identifying windows of heightened vulnerability. ENVIRONMENT INTERNATIONAL 2017; 107:258-265. [PMID: 28764921 PMCID: PMC5567845 DOI: 10.1016/j.envint.2017.07.021] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 07/02/2017] [Accepted: 07/24/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND Early life BPA exposure could affect neurobehavior, but few studies have investigated whether there are developmental periods when the fetus or child is more vulnerable to these potential effects. OBJECTIVES We explored windows of vulnerability to BPA exposure in a multiethnic cohort of 228 mothers and their children from Cincinnati, Ohio. METHODS We measured urinary BPA concentrations at up to two prenatal and six postnatal time points from the 2nd trimester of pregnancy until the child was age 8years. At age 8years, we administered the Behavioral Assessment System for Children-2 (BASC-2), Behavior Rating Inventory of Executive Function, and Wechsler Intelligence Scale for Children-IV. We estimated covariate-adjusted differences in composite scores from each instrument using a multiple informant model designed to identify heightened windows of vulnerability. RESULTS Among all children, there was not strong evidence that the associations between BPA and neurobehavior varied by the timing of exposure (Visit x BPA p-values≥0.16). However, child sex modified the associations of repeated BPA measures with BASC-2 scores (Visit x Sex x BPA p-values=0.02-0.23). For example, each 10-fold increase in prenatal BPA was associated with more externalizing behaviors in girls (β=6.2, 95% CI: 0.8, 11.6), but not boys (β=-0.8, 95% CI: -5.0, 3.4). In contrast, a 10-fold increase in 8-year BPA was associated with more externalizing behaviors in boys (β=3.9, 95% CI: 0.6, 7.2), but not girls (β=0.3, 95% CI: -3.5, 4.1). CONCLUSIONS We found that sex-dependent associations between BPA and child neurobehavior may depend on the timing of BPA exposure.
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Affiliation(s)
- Shaina L Stacy
- Department of Epidemiology, Brown University, Providence, RI 02912, United States
| | | | - Antonia M Calafat
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, United States
| | - Aimin Chen
- Division of Epidemiology, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH 45267, United States
| | - Kimberly Yolton
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, United States
| | - Bruce P Lanphear
- Child and Family Research Institute, BC Children's Hospital and the Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia V5A 1S6, Canada
| | - Joseph M Braun
- Department of Epidemiology, Brown University, Providence, RI 02912, United States.
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Philippat C, Nakiwala D, Calafat AM, Botton J, De Agostini M, Heude B, Slama R. Prenatal Exposure to Nonpersistent Endocrine Disruptors and Behavior in Boys at 3 and 5 Years. ENVIRONMENTAL HEALTH PERSPECTIVES 2017; 125:097014. [PMID: 28937960 PMCID: PMC5915182 DOI: 10.1289/ehp1314] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 05/23/2017] [Accepted: 06/19/2017] [Indexed: 05/12/2023]
Abstract
BACKGROUND Sex-specific associations have been reported between phthalates, bisphenol A (BPA), and child behavior. No data on large study populations are available for other phenols with possible endocrine-disrupting properties. OBJECTIVES We aimed to study associations between prenatal exposure to phthalates and several phenols on behavior among male infants. METHODS We quantified 11 phthalate metabolites and nine phenols (four parabens, benzophenone-3, BPA, two dichlorophenols, triclosan) in spot urine samples collected during pregnancy among EDEN cohort mothers who delivered a boy. Mothers completed the Strength and Difficulties Questionnaire (SDQ) when their children were 3.1 (n=529) and 5.6 (n=464) y old. RESULTS BPA was positively associated with the relationship problems subscale at 3 y [incidence rate ratio (IRR): 1.11; 95% confidence interval (CI): 1.03, 1.20] and the hyperactivity-inattention subscale scores at 5 y (IRR: 1.08; 95% CI: 1.01, 1.14). Mono-n-butyl phthalate (MnBP) was positively associated with internalizing behavior, relationship problem, and emotional symptom scores at 3 y. Monobenzyl phthalate (MBzP) was positively associated with internalizing behavior and relationship problems scores at 3 y. After dichotomizing SDQ scores, triclosan tended to be positively associated with emotional symptom subscales at both 3 and 5 y. CONCLUSIONS The observed associations between BPA, MnBP, and behavior in boys are consistent with previous findings. Further health impact assessment studies based on dose-response functions corrected for exposure misclassification are required to quantify the public health burden possibly entailed by such associations. https://doi.org/10.1289/EHP1314.
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Affiliation(s)
- Claire Philippat
- Institute for Advanced Biosciences, INSERM U1209, CNRS UMR 5309, University Grenoble Alpes , Grenoble, France
| | - Dorothy Nakiwala
- Institute for Advanced Biosciences, INSERM U1209, CNRS UMR 5309, University Grenoble Alpes , Grenoble, France
| | | | - Jérémie Botton
- U1153 Epidemiology and Biostatistics Sorbonne Paris Cité Research Centre (CRESS) , Early Origin of the Child's Health and Development (ORCHAD) Team, Inserm, Villejuif, France
- Université Paris Descartes , Villejuif, France
- Faculty of Pharmacy, Université Paris-Sud, Université Paris-Saclay , Châtenay-Malabry, France
| | - Maria De Agostini
- U1153 Epidemiology and Biostatistics Sorbonne Paris Cité Research Centre (CRESS) , Early Origin of the Child's Health and Development (ORCHAD) Team, Inserm, Villejuif, France
- Université Paris Descartes , Villejuif, France
| | - Barbara Heude
- U1153 Epidemiology and Biostatistics Sorbonne Paris Cité Research Centre (CRESS) , Early Origin of the Child's Health and Development (ORCHAD) Team, Inserm, Villejuif, France
- Université Paris Descartes , Villejuif, France
| | - Rémy Slama
- Institute for Advanced Biosciences, INSERM U1209, CNRS UMR 5309, University Grenoble Alpes , Grenoble, France
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Hubbs-Tait L, Nation JR, Krebs NF, Bellinger DC. Neurotoxicants, Micronutrients, and Social Environments. Psychol Sci Public Interest 2016; 6:57-121. [DOI: 10.1111/j.1529-1006.2005.00024.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
SUMMARY—Systematic research evaluating the separate and interacting impacts of neurotoxicants, micronutrients, and social environments on children's cognition and behavior has only recently been initiated. Years of extensive human epidemiologic and animal experimental research document the deleterious impact of lead and other metals on the nervous system. However, discrepancies among human studies and between animal and human studies underscore the importance of variations in child nutrition as well as social and behavioral aspects of children's environments that mitigate or exacerbate the effects of neurotoxicants. In this monograph, we review existing research on the impact of neurotoxic metals, nutrients, and social environments and interactions across the three domains. We examine the literature on lead, mercury, manganese, and cadmium in terms of dispersal, epidemiology, experimental animal studies, effects of social environments, and effects of nutrition. Research documenting the negative impact of lead on cognition and behavior influenced reductions by the Center for Disease Control in child lead-screening guidelines from 30 micrograms per deciliter (μg/dL) in 1975 to 25 μg/dL in 1985 and to 10 μg/dL in 1991. A further reduction is currently being considered. Experimental animal research documents lead's alteration of glutamate-neurotransmitter (particularly N-methyl-D-aspartate) activity vital to learning and memory. In addition, lead induces changes in cholinergic and dopaminergic activity. Elevated lead concentrations in the blood are more common among children living in poverty and there is some evidence that socioeconomic status influences associations between lead and child outcomes. Micronutrients that influence the effects of lead include iron and zinc. Research documenting the negative impact of mercury on children (as well as adults) has resulted in a reference dose (RfD) of 0.1 microgram per kilogram of body weight per day (μg/kg/day). In animal studies, mercury interferes with glutamatergic, cholinergic, and dopaminergic activity. Although evidence for interactions of mercury with children's social contexts is minimal, researchers are examining interactions of mercury with several nutrients. Research on the effects of cadmium and manganese on child cognition and behavior is just beginning. Experimental animal research links cadmium to learning deficits, manganese to behaviors characteristic of Parkinson's disease, and both to altered dopaminergic functioning. We close our review with a discussion of policy implications, and we recommend interdisciplinary research that will enable us to bridge gaps within and across domains.
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Affiliation(s)
- Laura Hubbs-Tait
- Department of Human Development and Family Science, Oklahoma State University
| | | | - Nancy F. Krebs
- Department of Pediatrics, University of Colorado School of Medicine
| | - David C. Bellinger
- Department of Neurology, Harvard Medical School; Department of Environmental Health, Harvard School of Public Health; and Children's Hospital Boston
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Abstract
The impact of toxins on the developing brain is usually subtle for an individual child, but the damage can be substantial at the population level. Numerous challenges must be addressed to definitively test the impact of toxins on brain development in children: We must quantify exposure using a biologic marker or pollutant; account for an ever-expanding set of potential confounders; identify critical windows of vulnerability; and repeatedly examine the association of biologic markers of toxins with intellectual abilities, behaviors, and brain function in distinct cohorts. Despite these challenges, numerous toxins have been implicated in the development of intellectual deficits and mental disorders in children. Yet, too little has been done to protect children from these ubiquitous but insidious toxins. The objective of this review is to provide an overview on the population impact of toxins on the developing brain and describe implications for public health.
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Affiliation(s)
- Bruce P Lanphear
- Child and Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia V5A 1S6, Canada
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Park S, Cho SC, Hong YC, Kim JW, Shin MS, Yoo HJ, Han DH, Cheong JH, Kim BN. Environmental tobacco smoke exposure and children's intelligence at 8-11 years of age. ENVIRONMENTAL HEALTH PERSPECTIVES 2014; 122:1123-8. [PMID: 24911003 PMCID: PMC4181918 DOI: 10.1289/ehp.1307088] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 06/02/2014] [Indexed: 05/25/2023]
Abstract
BACKGROUND Evidence supporting a link between postnatal environmental tobacco smoke (ETS) exposure and cognitive problems among children is mounting, but inconsistent. OBJECTIVES We examined the relationship between ETS exposure, measured using urine cotinine, and IQ scores in Korean school-aged children. METHODS The participants were 996 children 8-11 years of age recruited from five administrative regions in South Korea. We performed a cross-sectional analysis of urinary cotinine concentrations and IQ scores obtained using the abbreviated form of a Korean version of the Wechsler Intelligence Scales for Children. Associations were adjusted for potential confounders, and estimates were derived with and without adjustment for mother's Full-Scale IQ (FSIQ) score. RESULTS After adjusting for sociodemographic and developmental covariates, urinary cotinine concentrations were inversely associated with FSIQ, Verbal IQ (VIQ), Performance IQ (PIQ), vocabulary, math, and block design scores. Following further adjustment for maternal IQ, only the VIQ scores remained significantly associated with urinary cotinine concentration (B = -0.31; 95% CI: -0.60, -0.03 for a 1-unit increase in natural log-transformed urine cotinine concentration; p = 0.03). CONCLUSION Urine cotinine concentrations were inversely associated with children's VIQ scores before and after adjusting for maternal IQ. Further prospective studies with serial measurements of cotinine are needed to confirm our findings.
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Affiliation(s)
- Subin Park
- Department of Psychiatry, Seoul National Hospital, Seoul, Republic of Korea
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11
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Braun JM, Froehlich T, Kalkbrenner A, Pfeiffer CM, Fazili Z, Yolton K, Lanphear BP. Brief report: are autistic-behaviors in children related to prenatal vitamin use and maternal whole blood folate concentrations? J Autism Dev Disord 2014; 44:2602-7. [PMID: 24710813 PMCID: PMC4167931 DOI: 10.1007/s10803-014-2114-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Prenatal multivitamin/folic acid supplement use may reduce the risk of autism spectrum disorders. We investigated whether 2nd trimester prenatal vitamin use and maternal whole blood folate (WBF) concentrations were associated with Social Responsiveness Scale (SRS) scores at 4-5 years of age in a prospective cohort of 209 mother-child pairs. After confounder adjustment, children born to women taking prenatal vitamins weekly/daily (n = 179) had lower odds of clinically elevated SRS scores (odds ratio 0.26; 95 % confidence interval 0.08, 0.89) than those who rarely/never took them (n = 30). WBF concentrations were not associated with SRS scores. The lack of association between WBF and autistic-behaviors may be due to the timing of biomarker measures relative to critical periods of brain development, confounding, or other modifying factors.
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Affiliation(s)
- Joseph M Braun
- Department of Epidemiology, Brown University School of Public Health, Brown University, Providence, RI, 02912, USA,
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12
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Banner W, Kahn CM. Low blood lead level effects on intelligence: can a dose-response curve be determined from the epidemiological data? Clin Toxicol (Phila) 2014; 52:113-7. [PMID: 24443996 DOI: 10.3109/15563650.2013.876544] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONTEXT. Recent publications have graphically demonstrated a curvilinear relationship between measures of intelligence and blood lead levels at low concentrations (< 10 mcg/dl). This led to speculation that a greater biologic effect occurs at lower concentrations. Critics of this conclusion hypothesized that this graphical relationship may be a function of the underlying distributions of these variables. OBJECTIVE. To study the impact of the distribution of data on the shape of apparent dose-response curves. METHODS. Random data based on varied distributions were constructed to simulate a previous study using a single, randomly generated covariate income (Inc) to demonstrate the impact of normally versus exponentially distributed data on the shape of the graph of intelligence quotient (IQ) versus blood lead. We also used an existing database of US blood lead levels and constructed a similar model of income and IQ using both assumptions of distribution for the intermediate variable income. RESULTS. When both lead and income are exponentially distributed, the graph of lead and IQ will be a curve. CONCLUSION. The apparent shape of a dose-response relationship from simulated epidemiological data is nonlinear when one variable and a covariate are exponentially distributed. A non-linear biological relationship should not be assumed and in fact may be the least likely explanation. The use of observational epidemiological data to discern a dose-response relationship between two variables may be misleading.
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Affiliation(s)
- W Banner
- Department of Pharmacy Practice, College of Pharmacy, University of Oklahoma , Oklahoma City, OK , USA
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Exposure to widespread environmental toxicants and children's cognitive development and behavioral problems. Int J Occup Med Environ Health 2013; 26:185-204. [PMID: 23715930 DOI: 10.2478/s13382-013-0099-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 07/25/2012] [Indexed: 11/20/2022] Open
Abstract
Nowadays a special attention is focused on prenatal and childhood exposures to a variety of contaminants in the environment, especially toxicants widely present in the environment and their impact on children's health and neurodevelopment. This article aims at evaluating the impact of exposure to several widespread toxicants including: polycyclic aromatic hydrocarbons (PAHs), phthalates, bisphenol A, brominated flame retardants and gas cooking on children's cognitive development and behavioral problems by reviewing most recent published literature. Epidemiological studies focusing on exposure to widespread toxicants and children's development for the last eleven years were identified by a search of the PubMed, Medline, Ebsco and Toxnet literature bases. The combination of following key words was used: 1) referring to the exposure: pregnancy, prenatal exposure, postnatal exposure, gas cooking, exposure to phthalates, bisphenol A, brominated flame retardants, PAHs and 2) referring to outcome: neurodevelopment, neurobehavior, psychomotor development, behavioral problems, cognitive development, mental health, school achievements, learning abilities. The results from the presented studies suggest that there are strong and rather consistent indications that the developing nervous system is particularly vulnerable to insult from low levels of exposure to widespread environmental contaminants such as: phthalates, bisphenol A, brominated flame retardants, polycyclic aromatic hydrocarbons, gas cooking. Considering the suggested health effects, more epidemiologic data is urgently needed and, in the meantime, precautionary policies must be implemented.
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Burns CJ, McIntosh LJ, Mink PJ, Jurek AM, Li AA. Pesticide exposure and neurodevelopmental outcomes: review of the epidemiologic and animal studies. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2013; 16:127-283. [PMID: 23777200 PMCID: PMC3705499 DOI: 10.1080/10937404.2013.783383] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Assessment of whether pesticide exposure is associated with neurodevelopmental outcomes in children can best be addressed with a systematic review of both the human and animal peer-reviewed literature. This review analyzed epidemiologic studies testing the hypothesis that exposure to pesticides during pregnancy and/or early childhood is associated with neurodevelopmental outcomes in children. Studies that directly queried pesticide exposure (e.g., via questionnaire or interview) or measured pesticide or metabolite levels in biological specimens from study participants (e.g., blood, urine, etc.) or their immediate environment (e.g., personal air monitoring, home dust samples, etc.) were eligible for inclusion. Consistency, strength of association, and dose response were key elements of the framework utilized for evaluating epidemiologic studies. As a whole, the epidemiologic studies did not strongly implicate any particular pesticide as being causally related to adverse neurodevelopmental outcomes in infants and children. A few associations were unique for a health outcome and specific pesticide, and alternative hypotheses could not be ruled out. Our survey of the in vivo peer-reviewed published mammalian literature focused on effects of the specific active ingredient of pesticides on functional neurodevelopmental endpoints (i.e., behavior, neuropharmacology and neuropathology). In most cases, effects were noted at dose levels within the same order of magnitude or higher compared to the point of departure used for chronic risk assessments in the United States. Thus, although the published animal studies may have characterized potential neurodevelopmental outcomes using endpoints not required by guideline studies, the effects were generally observed at or above effect levels measured in repeated-dose toxicology studies submitted to the U.S. Environmental Protection Agency (EPA). Suggestions for improved exposure assessment in epidemiology studies and more effective and tiered approaches in animal testing are discussed.
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Affiliation(s)
| | | | - Pamela J. Mink
- Allina Health Center for Healthcare Research & Innovation, Minneapolis, Minnesota, USA
| | - Anne M. Jurek
- Allina Health Center for Healthcare Research & Innovation, Minneapolis, Minnesota, USA
| | - Abby A. Li
- Exponent, Inc., Menlo Park, California, USA
- Address correspondence to Abby A. Li, PhD, Attn: Rebecca Edwards, Exponent, Inc., Health Sciences Group, 149 Commonwealth Drive, Menlo Park, CA 94025-1133, USA. E-mail:
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Cho SC, Bhang SY, Hong YC, Shin MS, Kim BN, Kim JW, Yoo HJ, Cho IH, Kim HW. Relationship between environmental phthalate exposure and the intelligence of school-age children. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:1027-32. [PMID: 20194078 PMCID: PMC2920903 DOI: 10.1289/ehp.0901376] [Citation(s) in RCA: 180] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Accepted: 03/01/2010] [Indexed: 05/18/2023]
Abstract
BACKGROUND Concern over phthalates has emerged because of their potential toxicity to humans. OBJECTIVE We investigated the relationship between the urinary concentrations of phthalate metabolites and children's intellectual functioning. METHODS This study enrolled 667 children at nine elementary schools in five South Korean cities. A cross-sectional examination of urine phthalate concentrations was performed, and scores on neuropsychological tests were obtained from both the children and their mothers. RESULTS We measured mono-2-ethylhexyl phthalate (MEHP) and mono(2-ethyl-5-oxohexyl)phthalate (MEOHP), both metabolites of di(2-ethylhexyl)phthalate (DEHP), and mono-n-butyl phthalate (MBP), a metabolite of dibutyl phthalate (DBP), in urine samples. The geometric mean (ln) concentrations of MEHP, MEOHP, and MBP were 21.3 microg/L [geometric SD (GSD) = 2.2 microg/L; range, 0.5-445.4], 18.0 microg/L (GSD = 2.4; range, 0.07-291.1), and 48.9 microg/L (GSD = 2.2; range, 2.1-1645.5), respectively. After adjusting for demographic and developmental covariates, the Full Scale IQ and Verbal IQ scores were negatively associated with DEHP metabolites but not with DBP metabolites. We also found a significant negative relationship between the urine concentrations of the metabolites of DEHP and DBP and children's vocabulary subscores. After controlling for maternal IQ, a significant inverse relationship between DEHP metabolites and vocabulary subscale score remained. Among boys, we found a negative association between increasing MEHP phthalate concentrations and the sum of DEHP metabolite concentrations and Wechsler Intelligence Scale for Children vocabulary score; however, among girls, we found no significant association between these variables. CONCLUSION Controlling for maternal IQ and other covariates, the results show an inverse relationship between phthalate metabolites and IQ scores; however, given the limitations in cross-sectional epidemiology, prospective studies are needed to fully explore these associations.
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Affiliation(s)
- Soo-Churl Cho
- Division of Child and Adolescent Psychiatry, Department of Psychiatry and Institute of Human Behavioral Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Soo-Young Bhang
- Department of Psychiatry, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea
- Address correspondence to S. Bhang, Department of Psychiatry, Ulsan University Hospital, University of Ulsan College of Medicine, 290-3 Jeonha-Dong, Dong-Gu, Ulsan, 682-714, South Korea. Telephone: 82-52-250- 7070. Fax: 82-52-232-3309. E-mail:
| | - Yun-Chul Hong
- Department of Preventive Medicine, Seoul National University College of Medicine and Institute of Environmental Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
| | - Min-Sup Shin
- Division of Child and Adolescent Psychiatry, Department of Psychiatry and Institute of Human Behavioral Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Boong-Nyun Kim
- Division of Child and Adolescent Psychiatry, Department of Psychiatry and Institute of Human Behavioral Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jae-Won Kim
- Division of Child and Adolescent Psychiatry, Department of Psychiatry and Institute of Human Behavioral Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hee-Jung Yoo
- Department of Psychiatry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - In Hee Cho
- Department of Psychiatry, Gil Medical Center, Gachon University of Medicine and Science, Incheon, Republic of Korea
| | - Hyo-Won Kim
- Department of Neuropsychiatry, Dongguk University International Hospital, Dongguk University College of Medicine, Goyang, Republic of Korea
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Braun JM, Yolton K, Dietrich KN, Hornung R, Ye X, Calafat AM, Lanphear BP. Prenatal bisphenol A exposure and early childhood behavior. ENVIRONMENTAL HEALTH PERSPECTIVES 2009; 117:1945-52. [PMID: 20049216 PMCID: PMC2799471 DOI: 10.1289/ehp.0900979] [Citation(s) in RCA: 335] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Accepted: 09/25/2009] [Indexed: 05/18/2023]
Abstract
BACKGROUND Prenatal exposure to bisphenol A (BPA) increases offspring aggression and diminishes differences in sexually dimorphic behaviors in rodents. OBJECTIVE We examined the association between prenatal BPA exposure and behavior in 2-year-old children. METHODS We used data from 249 mothers and their children in Cincinnati, Ohio (USA). Maternal urine was collected around 16 and 26 weeks of gestation and at birth. BPA concentrations were quantified using high-performance liquid chromatography-isotope-dilution tandem mass spectrometry. Child behavior was assessed at 2 years of age using the second edition of the Behavioral Assessment System for Children (BASC-2). The association between prenatal BPA concentrations and BASC-2 scores was analyzed using linear regression. RESULTS Median BPA concentrations were 1.8 (16 weeks), 1.7 (26 weeks), and 1.3 (birth) ng/mL. Mean (+/- SD) BASC-2 externalizing and internalizing scores were 47.6 +/- 7.8 and 44.8 +/- 7.0, respectively. After adjustment for confounders, log(10)-transformed mean prenatal BPA concentrations were associated with externalizing scores, but only among females [beta = 6.0; 95% confidence interval (CI), 0.1-12.0]. Compared with 26-week and birth concentrations, BPA concentrations collected around 16 weeks were more strongly associated with externalizing scores among all children (beta = 2.9; 95% CI, 0.2-5.7), and this association was stronger in females than in males. Among all children, measurements collected at <or= 16 weeks showed a stronger association (beta = 5.1; 95% CI, 1.5-8.6) with externalizing scores than did measurements taken at 17-21 weeks (beta = 0.6; 95% CI, -2.9 to 4.1). CONCLUSIONS These results suggest that prenatal BPA exposure may be associated with externalizing behaviors in 2-year-old children, especially among female children.
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Affiliation(s)
- Joe M. Braun
- Department of Epidemiology, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
| | - Kimberly Yolton
- Department of Pediatrics, Division of General and Community Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Kim N. Dietrich
- Department of Environmental Health, Division of Epidemiology and Biostatistics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Richard Hornung
- Department of Pediatrics, Division of General and Community Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Xiaoyun Ye
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Antonia M. Calafat
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Bruce P. Lanphear
- Department of Pediatrics, Division of General and Community Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
- Child and Family Research Institute, BC Children’s Hospital and the Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
- Address correspondence to B. Lanphear, 3415 Ash St., Vancouver, BC V5Z 3E5 Canada. Telephone: (778) 387-3939. Fax: (513) 636-4402. E-mail:
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Glass TA, Bandeen-Roche K, McAtee M, Bolla K, Todd AC, Schwartz BS. Neighborhood psychosocial hazards and the association of cumulative lead dose with cognitive function in older adults. Am J Epidemiol 2009; 169:683-92. [PMID: 19155330 DOI: 10.1093/aje/kwn390] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Before the 1970s, today's older Americans were exposed to high levels of lead in the environment. The authors previously reported that lifetime cumulative lead dose was associated with lower cognitive test performance in older adults. Experiments suggest that environmental stress may intensify the detrimental influence of lead. No large, population-based studies of this question have been done. The authors evaluated whether cross-sectional associations of tibia lead with cognitive function were modified by neighborhood psychosocial hazards in the Baltimore Memory Study (2001-2005), a longitudinal cohort study of determinants of cognitive decline. Tibia lead was measured via (109)Cd-induced K-shell X-ray fluorescence. Neighborhood psychosocial hazards were measured independently of study subjects. Complete data were available among 1,001 demographically diverse adults aged 50-70 years, randomly selected from 65 contiguous neighborhoods in Baltimore City. Hierarchical mixed-effects regression models showed that neighborhood psychosocial hazards exacerbated the adverse associations of tibia lead in 3 of 7 cognitive domains after adjustment for age, sex, race/ethnicity, education, testing technician, and time of day (language, P = 0.039; processing speed, P = 0.067; executive functioning, P = 0.025). The joint occurrence of environmental stress and lead exposure across the life span may partially explain persistent racial/ethnic and socioeconomic disparities in cognitive function in late life.
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Affiliation(s)
- Thomas A Glass
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
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Lanphear BP, Hornung RW, Khoury J, Dietrich KN, Cory-Slechta DA, Canfield RL. The conundrum of unmeasured confounding: Comment on: "Can some of the detrimental neurodevelopmental effects attributed to lead be due to pesticides? by Brian Gulson". THE SCIENCE OF THE TOTAL ENVIRONMENT 2008; 396:196-200. [PMID: 18316114 PMCID: PMC2474734 DOI: 10.1016/j.scitotenv.2008.01.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 01/15/2008] [Accepted: 01/15/2008] [Indexed: 05/13/2023]
Abstract
The problem described by Dr. Brian Gulson - confounding by unmeasured exposures to pesticides - is only the most recent in a series of potential confounders cited to explain the observed effect of lead on children's intellectual abilities or behavioral problems. Despite the persistent problem of unmeasured confounders, there are several lines of evidence implicating lead as a toxicant at blood lead levels <10 microg/dL. First, in striking contrast with pesticides, there is considerable evidence from numerous studies linking low-level lead exposure with cognitive deficits and behavioral problems, even after controlling for a variety of potential confounders. Second, the consistency of evidence from diverse cohorts and distinct, if not always directly measured potential confounders - enhances our confidence that the lead effect observed at blood lead levels <10 microg/dL is not attributable to unmeasured confounders. Third, in our reanalysis of the Rochester Lead Study, the inclusion of parent-reported mouthing behaviors and breastfeeding status did not attenuate the effect of lead exposure on children's intellectual function. Finally, although we can never entirely dismiss unmeasured confounding in observational studies, we can rely on experimental studies of lead-exposed animals to confirm that lead is a toxicant. Thus, while we must remain vigilant for unmeasured or poorly measured confounders, it is crucial to balance the endless search for confounders with the evidence of toxicity and the need to take action to protect public health. The alternative, to perpetually permit children to be exposed to lead and other emerging toxicants, is both absurd and unacceptable.
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Affiliation(s)
- Bruce P Lanphear
- Cincinnati Children's Environmental Health Center, Department of Pediatrics and of Environmental Health, Cincinnati Children's Hospital Medical Center, The University of Cincinnati, Cincinnati, Ohio, USA.
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Solon O, Riddell TJ, Quimbo SA, Butrick E, Aylward GP, Lou Bacate M, Peabody JW. Associations between cognitive function, blood lead concentration, and nutrition among children in the central Philippines. J Pediatr 2008; 152:237-43. [PMID: 18206696 DOI: 10.1016/j.jpeds.2007.09.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2007] [Revised: 07/27/2007] [Accepted: 09/05/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVE Because little is known about its effects on cognitive function among children in less-developed countries, we determined the impact of lead exposure from other nutritional determinants of cognitive ability. STUDY DESIGN Data were from a cross-sectional population-based stratified random sample of 877 children (age 6 months-5 years) participating in the Quality Improvement Demonstration Study we are conducting in the Philippines. With data from validated psychometric instruments, venous blood samples, and comprehensive survey instruments, we developed multi-stage models to account for endogenous determinants of blood lead levels (BLLs) and exogenous confounders of the association between BLLs and cognitive function. RESULTS A 1 microg/dL increase in BLL was associated with a 3.32 point decline in cognitive functioning in children aged 6 months to 3 years and a 2.47 point decline in children aged 3 to 5 years olds. BLL was inversely associated with hemoglobin and folate levels. Higher folate levels mitigated the negative association between BLL and cognitive function. CONCLUSIONS These population-based data suggest greater lead toxicity on cognitive function than previously reported. Our findings also suggest that folate and iron deficient children are more susceptible to the negative cognitive effects of lead. Folate supplementation may offer some protective effects against lead exposure.
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Affiliation(s)
- Orville Solon
- School of Economics, University of the Philippines, Diliman, Quezon City
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Jusko TA, Henderson CR, Lanphear BP, Cory-Slechta DA, Parsons PJ, Canfield RL. Blood lead concentrations < 10 microg/dL and child intelligence at 6 years of age. ENVIRONMENTAL HEALTH PERSPECTIVES 2008; 116:243-8. [PMID: 18288325 PMCID: PMC2235210 DOI: 10.1289/ehp.10424] [Citation(s) in RCA: 315] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Accepted: 11/03/2007] [Indexed: 05/17/2023]
Abstract
BACKGROUND Few studies provide data directly relevant to the question of whether blood lead concentrations < 10 microg/dL adversely affect children's cognitive function. OBJECTIVE We examined the association between blood lead concentrations assessed throughout early childhood and children's IQ at 6 years of age. METHODS Children were followed from 6 months to 6 years of age, with determination of blood lead concentrations at 6, 12, 18, and 24 months, and 3, 4, 5, and 6 years of age. At 6 years of age, intelligence was assessed in 194 children using the Wechsler Preschool and Primary Scale of Intelligence-Revised. We used general linear and semiparametic models to estimate and test the association between blood lead concentration and IQ. RESULTS After adjustment for maternal IQ, HOME scale scores, and other potential confounding factors, lifetime average blood lead concentration (mean = 7.2 microg/dL; median = 6.2 microg/dL) was inversely associated with Full-Scale IQ (p = 0.006) and Performance IQ scores (p = 0.002). Compared with children who had lifetime average blood lead concentrations < 5 microg/dL, children with lifetime average concentrations between 5 and 9.9 microg/dL scored 4.9 points lower on Full-Scale IQ (91.3 vs. 86.4, p = 0.03). Nonlinear modeling of the peak blood lead concentration revealed an inverse association (p = 0.003) between peak blood lead levels and Full-Scale IQ down to 2.1 microg/dL, the lowest observed peak blood lead concentration in our study. CONCLUSIONS Evidence from this cohort indicates that children's intellectual functioning at 6 years of age is impaired by blood lead concentrations well below 10 microg/dL, the Centers for Disease Control and Prevention definition of an elevated blood lead level.
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Affiliation(s)
- Todd A. Jusko
- Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, Seattle, Washington, USA
| | | | - Bruce P. Lanphear
- Cincinnati Children’s Environmental Health Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Deborah A. Cory-Slechta
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - Patrick J. Parsons
- Trace Elements Laboratory, Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Environmental Health Sciences, School of Public Health, The University at Albany, State University of New York, Albany, New York, USA
| | - Richard L. Canfield
- Division of Nutritional Sciences, Cornell University, Ithaca, New York, USA
- Address correspondence to R.L. Canfield, Division of Nutritional Sciences, B-09 Savage Hall, Cornell University, Ithaca, NY 14853 USA. Telephone: (607) 255-9575. Fax: (607) 255-0178. E-mail:
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Patel AB, Mamtani MR, Thakre TP, Kulkarni H. Association of umbilical cord blood lead with neonatal behavior at varying levels of exposure. Behav Brain Funct 2006; 2:22. [PMID: 16803627 PMCID: PMC1557521 DOI: 10.1186/1744-9081-2-22] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Accepted: 06/27/2006] [Indexed: 12/01/2022] Open
Abstract
Background In the light of the ongoing debate about lowering the cut-off for acceptable blood lead level to <5 μg/dL from the currently recommended level of <10 μg/dL, we considered whether prenatal exposure to varying levels of lead is associated with similar or disparate effects on neonatal behavior. Methods Using Brazelton's Neonatal Behavioral Assessment Scale (NBAS), an epidemiological approach and robust statistical techniques like multivariate linear regression, logistic regression, Poisson regression and structural equations modeling analyses we estimated the simultaneous indirect effects of umbilical cord blood lead (CBL) levels and other neonatal covariates on the NBAS clusters. Results We observed that when analyzed in all study subjects, the CBL levels independently and strongly influenced autonomic stability and abnormal reflexes clusters. However, when the analysis was restricted to neonates with CBL <10 μg/dL, CBL levels strongly influenced the range of state, motor and autonomic stability clusters. Abnormal walking reflex was consistently associated with an increased CBL level irrespective of the cut-off for CBL, however, only at the lower cut-offs were the predominantly behavioral effects of CBL discernible. Conclusion Our results further endorse the need to be cognizant of the detrimental effects of blood lead on neonates even at a low-dose prenatal exposure.
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Affiliation(s)
- Archana B Patel
- Clinical Epidemiology Unit, Indira Gandhi Government Medical College, Nagpur, India
- Lata Medical Research Foundation, Nagpur, India
| | | | - Tushar P Thakre
- Lata Medical Research Foundation, Nagpur, India
- University of North Texas Health Science Center, Fort Worth, TX, USA
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Counter SA, Buchanan LH, Ortega F. Neurocognitive impairment in lead-exposed children of Andean lead-glazing workers. J Occup Environ Med 2005; 47:306-12. [PMID: 15761328 DOI: 10.1097/01.jom.0000155717.45594.65] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The level of lead (Pb) exposure necessary to induce intellectual impairment has not been firmly established. Some studies using conventional language-based intelligence tests have reported that pediatric blood lead (PbB) levels lower than 10 microg/dL (0.483 micromol/L) are associated with neurocognitive impairment. However, these tests may introduce cultural biases in the assessment of intellectual functioning. The objective of this study was to assess the effects of PbB concentration on nonverbal intelligence in Andean children with chronic environmental Pb exposure using a nonlanguage-based test of cognitive functioning. METHODS Using Raven Colored Progressive Matrices (RCPM) as a measure of nonverbal intelligence, this study investigated the effects of Pb exposure (biomarker: PbB levels) on intellectual functioning in 188 chronically Pb-exposed children (age range: 5.33-11.67 years) of Ecuadorian Andean Pb-glazing workers. RESULTS The mean PbB level of the 188 children was 29.3 microg/dL (range: 3.5-94.3 microg/dL). Forty-seven children had PbB levels <10 microg/dL (Centers for Disease Control and Prevention [CDC] I classification), of which 30 had abnormal (ie, < or =25th percentile) RCPM standard scores. Of the 141 children with PbB levels > or =10 microg/dL, 97 had abnormal RCPM scores. A regression analysis revealed a statistically significant negative association (r = -0.331, P < 0.0001) between PbB level and RCPM standard score. Conversion of RCPM standard scores to estimated IQ scores showed an approximate two-point decrease in IQ for each 10-microg/dL increment in PbB level from 10 to >70 microg/dL. CONCLUSIONS Performance on a test of nonverbal intelligence was inversely associated with chronic Pb exposure in Andean children with PbB levels below and above the CDC risk management level of 10 microg/dL, with the decline in test scores suggesting a dose-response relationship.
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Affiliation(s)
- S Allen Counter
- Department of Neurology, Harvard Medical School/The Biological Laboratories, 16 Divinity Avenue, Cambridge, MA 02138, USA.
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Measuring Mercury Concentration. Epidemiology 2005. [DOI: 10.1097/01.ede.0000147361.21851.3f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Jusko TA. Comments on "Recent developments in low-level lead exposure and intellectual impairment in children". ENVIRONMENTAL HEALTH PERSPECTIVES 2005; 113:A16-A17. [PMID: 15631953 PMCID: PMC1253735 DOI: 10.1289/ehp.113-1253736] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Affiliation(s)
- Todd A. Jusko
- Department of Epidemiology, University of Washington, Seattle, Washington, E-mail:
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