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Bah HAF, Santos NRD, Costa DO, Carvalho CFD, Martinez VO, Gomes-Júnior EA, Antônio Menezes-Filho J. Environmental neurodevelopment toxicity from the perspective of Bronfenbrenner's bioecological model: a case study of toxic metals. CAD SAUDE PUBLICA 2023; 39:e00202022. [PMID: 37729303 PMCID: PMC10513156 DOI: 10.1590/0102-311xen202022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 06/04/2022] [Accepted: 06/16/2023] [Indexed: 09/22/2023] Open
Abstract
A growing body of literature reports the need for an integrated approach to study the effects of the physical environment on the neurodevelopment of children. Assessment of the true neurotoxicity of pollutants cannot be performed separately from the ecological and multidimensional contexts in which they act. In this study, from the perspective of the Bronfenbrenner's bioecological model, a conceptual model was developed that encompasses the social and biological characteristics of children from the gestational period to childhood, considering exposure to toxic metals. First, we present the toxicity of the main metals and some concept notions that we used in our framework, such as social and structural determinants of health, allostatic load, embodiment, and epigenetic concepts. Then, the main aspects of the Bronfenbrenner's bioecological model, which allow integration of the gene-social relationship in addition to the physical environment, where these metals act, are explained. Finally, we present and discuss the conceptual framework showing how, in real life, biological and social factors may together influence the neurodevelopment of children. Although this model is based on a group of contaminants, it opens new horizons on how environmental sciences, such as neurotoxicology and environmental epidemiology, can articulate with the theoretical models from human sciences to provide a broader approach to study the effects on human neurodevelopment.
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Affiliation(s)
- Homègnon Antonin Ferréol Bah
- Instituto de Saúde Coletiva, Universidade Federal da Bahia, Salvador, Brasil
- Faculdade de Farmácia, Universidade Federal da Bahia, Salvador, Brasil
| | | | | | | | | | | | - José Antônio Menezes-Filho
- Instituto de Saúde Coletiva, Universidade Federal da Bahia, Salvador, Brasil
- Faculdade de Farmácia, Universidade Federal da Bahia, Salvador, Brasil
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Payne-Sturges DC, Cory-Slechta DA, Puett RC, Thomas SB, Hammond R, Hovmand PS. Defining and Intervening on Cumulative Environmental Neurodevelopmental Risks: Introducing a Complex Systems Approach. ENVIRONMENTAL HEALTH PERSPECTIVES 2021; 129:35001. [PMID: 33688743 PMCID: PMC7945198 DOI: 10.1289/ehp7333] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 02/05/2021] [Accepted: 02/10/2021] [Indexed: 05/21/2023]
Abstract
BACKGROUND The combined effects of multiple environmental toxicants and social stressor exposures are widely recognized as important public health problems contributing to health inequities. However cumulative environmental health risks and impacts have received little attention from U.S. policy makers at state and federal levels to develop comprehensive strategies to reduce these exposures, mitigate cumulative risks, and prevent harm. An area for which the inherent limitations of current approaches to cumulative environmental health risks are well illustrated is children's neurodevelopment, which exhibits dynamic complexity of multiple interdependent and causally linked factors and intergenerational effects. OBJECTIVES We delineate how a complex systems approach, specifically system dynamics, can address shortcomings in environmental health risk assessment regarding exposures to multiple chemical and nonchemical stressors and reshape associated public policies. DISCUSSION Systems modeling assists in the goal of solving problems by improving the "mental models" we use to make decisions, including regulatory and policy decisions. In the context of disparities in children's cumulative exposure to neurodevelopmental stressors, we describe potential policy insights about the structure and behavior of the system and the types of system dynamics modeling that would be appropriate, from visual depiction (i.e., informal maps) to formal quantitative simulation models. A systems dynamics framework provides not only a language but also a set of methodological tools that can more easily operationalize existing multidisciplinary scientific evidence and conceptual frameworks on cumulative risks. Thus, we can arrive at more accurate diagnostic tools for children's' environmental health inequities that take into consideration the broader social and economic environment in which children live, grow, play, and learn. https://doi.org/10.1289/EHP7333.
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Affiliation(s)
- Devon C. Payne-Sturges
- Maryland Institute for Applied Environmental Health, University of Maryland School of UMD Public Health, College Park, Maryland, USA
| | | | - Robin C. Puett
- Maryland Institute for Applied Environmental Health, University of Maryland School of UMD Public Health, College Park, Maryland, USA
| | - Stephen B. Thomas
- Department of Health Policy and Management and Maryland Center for Health Equity, University of Maryland School of Public Health, College Park, Maryland, USA
| | - Ross Hammond
- Brown School of Social Work, Washington University, St. Louis, Missouri, USA
- Center on Social Dynamics and Policy, The Brookings Institution, Washington, DC, USA
| | - Peter S. Hovmand
- Center for Community Health Integration, Case Western Reserve University, Cleveland, Ohio, USA
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3
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Bangma JT, Hartwell H, Santos HP, O'Shea TM, Fry RC. Placental programming, perinatal inflammation, and neurodevelopment impairment among those born extremely preterm. Pediatr Res 2021; 89:326-335. [PMID: 33184498 PMCID: PMC7658618 DOI: 10.1038/s41390-020-01236-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 09/02/2020] [Accepted: 10/08/2020] [Indexed: 01/30/2023]
Abstract
Individuals born extremely preterm are at significant risk for impaired neurodevelopment. After discharge from the neonatal intensive care, associations between the child's well-being and factors in the home and social environment become increasingly apparent. Mothers' prenatal health and socioeconomic status are associated with neurodevelopmental outcomes, and emotional and behavioral problems. Research on early life risk factors and on mechanisms underlying inter-individual differences in neurodevelopment later in life can inform the design of personalized approaches to prevention. Here, we review early life predictors of inter-individual differences in later life neurodevelopment among those born extremely preterm. Among biological mechanisms that mediate relationships between early life predictors and later neurodevelopmental outcomes, we highlight evidence for disrupted placental processes and regulated at least in part via epigenetic mechanisms, as well as perinatal inflammation. In relation to these mechanisms, we focus on four prenatal antecedents of impaired neurodevelopment, namely, (1) fetal growth restriction, (2) maternal obesity, (3) placental microorganisms, and (4) socioeconomic adversity. In the future, this knowledge may inform efforts to detect and prevent adverse outcomes in infants born extremely preterm. IMPACT: This review highlights early life risk factors and mechanisms underlying inter-individual differences in neurodevelopment later in life. The review emphasizes research on early life risk factors (fetal growth restriction, maternal obesity, placental microorganisms, and socioeconomic adversity) and on mechanisms (disrupted placental processes and perinatal inflammation) underlying inter-individual differences in neurodevelopment later in life. The findings highlighted here may inform efforts to detect and prevent adverse outcomes in infants born extremely preterm.
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Affiliation(s)
- Jacqueline T Bangma
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Hadley Hartwell
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Hudson P Santos
- Biobehavioral Laboratory, School of Nursing, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Institute for Environmental Health Solutions, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - T Michael O'Shea
- Department of Pediatrics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Rebecca C Fry
- Biobehavioral Laboratory, School of Nursing, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Institute for Environmental Health Solutions, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Curriculum in Toxicology and Environmental Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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4
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Nilsen FM, Ruiz JD, Tulve NS. A Meta-Analysis of Stressors from the Total Environment Associated with Children's General Cognitive Ability. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17155451. [PMID: 32751096 PMCID: PMC7432904 DOI: 10.3390/ijerph17155451] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/17/2020] [Accepted: 07/20/2020] [Indexed: 12/31/2022]
Abstract
General cognitive ability, often referred to as ‘general intelligence’, comprises a variety of correlated abilities. Childhood general cognitive ability is a well-studied area of research and can be used to predict social outcomes and perceived success. Early life stage (e.g., prenatal, postnatal, toddler) exposures to stressors (i.e., chemical and non-chemical stressors from the total (built, natural, social) environment) can impact the development of childhood cognitive ability. Building from our systematic scoping review (Ruiz et al., 2016), we conducted a meta-analysis to evaluate more than 100 stressors related to cognitive development. Our meta-analysis identified 23 stressors with a significant increase in their likelihood to influence childhood cognitive ability by 10% or more, and 80 stressors were observed to have a statistically significant effect on cognitive ability. Stressors most impactful to cognition during the prenatal period were related to maternal health and the mother’s ability to access information relevant to a healthy pregnancy (e.g., diet, lifestyle). Stressors most impactful to cognition during the early childhood period were dietary nutrients (infancy), quality of social interaction (toddler), and exposure to toxic substances (throughout early childhood). In conducting this analysis, we examined the relative impact of real-world exposures on cognitive development to attempt to understand the inter-relationships between exposures to both chemical and non-chemical stressors and early developmental life stages. Our findings suggest that the stressors observed to be the most influential to childhood cognitive ability are not permanent and can be broadly categorized as activities/behaviors which can be modified to improve childhood cognition. This meta-analysis supports the idea that there are complex relationships between a child’s total environment and early cognitive development.
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Affiliation(s)
- Frances M. Nilsen
- Office of Research and Development, U.S. Environmental Protection Agency Research Triangle Park, Durham, NC 27709, USA; (J.D.C.R.); (N.S.T.)
- Correspondence: ; Tel.: +1-919-541-2574
| | - Jazmin D.C. Ruiz
- Office of Research and Development, U.S. Environmental Protection Agency Research Triangle Park, Durham, NC 27709, USA; (J.D.C.R.); (N.S.T.)
- Honeywell International, Buffalo, NY 14210, USA
| | - Nicolle S. Tulve
- Office of Research and Development, U.S. Environmental Protection Agency Research Triangle Park, Durham, NC 27709, USA; (J.D.C.R.); (N.S.T.)
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Reuben A, Elliott M, Caspi A. Implications of legacy lead for children's brain development. Nat Med 2020; 26:23-25. [PMID: 31932789 DOI: 10.1038/s41591-019-0731-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Aaron Reuben
- Department of Psychology & Neuroscience, Duke University, Durham, NC, USA
| | - Maxwell Elliott
- Department of Psychology & Neuroscience, Duke University, Durham, NC, USA
| | - Avshalom Caspi
- Department of Psychology & Neuroscience, Duke University, Durham, NC, USA. .,Department of Psychiatry & Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA. .,Center for Genomic and Computational Biology, Duke University, Durham, NC, USA. .,Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.
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6
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Abstract
Socioeconomic status (SES) is associated with health (physical and mental) and cognitive ability. Understanding and ameliorating the problems of low SES have long been goals of economics and sociology; in recent years, these have also become goals of neuroscience. However, opinion varies widely on the relevance of neuroscience to SES-related policy. The present article addresses the question of whether and how neuroscience can contribute to the development of social policy concerning poverty and the social and ethical risks inherent in trying. I argue that the neuroscience approach to SES-related policy has been both prematurely celebrated and peremptorily dismissed and that some of its possible social impacts have been viewed with excessive alarm. Neuroscience has already made modest contributions to SES-related policy, and its potential to have a more effective and beneficial influence can be expected to grow over the coming years.
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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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Manganese Exposure and Cognition Across the Lifespan: Contemporary Review and Argument for Biphasic Dose-Response Health Effects. Curr Environ Health Rep 2018; 3:392-404. [PMID: 27722879 DOI: 10.1007/s40572-016-0108-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Manganese (Mn) is both an essential micronutrient and potential neurotoxicant. This dual role underlies a growing body of literature demonstrating that Mn exhibits a biphasic dose-response relationship with neurocognitive outcomes. We reviewed recent epidemiologic studies from 2007 to 2016 that investigated the relationship between Mn exposure and cognitive outcomes across the lifespan: early life, school-aged children, and adulthood. In total, 27 research articles were included in this review: 12 pediatric and 15 adult studies (10 occupational and five environmental exposures). The majority of these studies provided evidence of the negative effects of Mn exposure on cognition. The pediatric literature provides evidence that both high and low levels of Mn are negatively associated with intellectual development. Future Mn research should include examination of non-linear relationships and multiple neurotoxicants across the lifespan and particularly during critical developmental windows.
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Cowell WJ, Wright RJ. Sex-Specific Effects of Combined Exposure to Chemical and Non-chemical Stressors on Neuroendocrine Development: a Review of Recent Findings and Putative Mechanisms. Curr Environ Health Rep 2018; 4:415-425. [PMID: 29027649 DOI: 10.1007/s40572-017-0165-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
PURPOSE OF REVIEW Environmental toxicants and psychosocial stressors share many biological substrates and influence overlapping physiological pathways. Increasing evidence indicates stress-induced changes to the maternal milieu may prime rapidly developing physiological systems for disruption by concurrent or subsequent exposure to environmental chemicals. In this review, we highlight putative mechanisms underlying sex-specific susceptibility of the developing neuroendocrine system to the joint effects of stress or stress correlates and environmental toxicants (bisphenol A, alcohol, phthalates, lead, chlorpyrifos, and traffic-related air pollution). RECENT FINDINGS We provide evidence indicating that concurrent or tandem exposure to chemical and non-chemical stressors during windows of rapid development is associated with sex-specific synergistic, potentiated and reversed effects on several neuroendocrine endpoints related to hypothalamic-pituitary-adrenal axis function, sex steroid levels, neurotransmitter circuits, and innate immune function. We additionally identify gaps, such as the role that the endocrine-active placenta plays, in our understanding of these complex interactions. Finally, we discuss future research needs, including the investigation of non-hormonal biomarkers of stress. We demonstrate multiple physiologic systems are impacted by joint exposure to chemical and non-chemical stressors differentially among males and females. Collectively, the results highlight the importance of evaluating sex-specific endpoints when investigating the neuroendocrine system and underscore the need to examine exposure to chemical toxicants within the context of the social environment.
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Affiliation(s)
- Whitney J Cowell
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA. .,Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, 12th Floor, Mailman School of Public Health, 722 West 168th St, New York, NY, 10032, USA.
| | - Rosalind J Wright
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Institute for Exposomic Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Associations among prenatal stress, maternal antioxidant intakes in pregnancy, and child temperament at age 30 months. J Dev Orig Health Dis 2017; 8:638-648. [PMID: 28651674 DOI: 10.1017/s2040174417000411] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Prenatal stress and prenatal nutrition each have demonstrable impact on fetal development, with implications for child neurodevelopment and behavior. However, few studies have examined their joint influences despite evidence of potential interactive effects. We examined associations among prenatal stress, prenatal antioxidant intakes, and child temperament in a sociodemographically diverse pregnancy cohort (N=137 mother-child dyads). In mid-pregnancy, mothers completed an assessment of recent negative life events as a measure of prenatal stress and an assessment of prenatal diet. When the children were 30 months of age, mothers completed the Early Childhood Behavior Questionnaire-Very Short form, which provides scores on child Negative Affectivity, Effortful Control, and Surgency/Extraversion. Linear regressions tested associations between maternal prenatal negative life events and child temperament, and effect modification by maternal prenatal antioxidant intakes (vitamins A, C, and E, magnesium, zinc, selenium, β-carotene). Analyses revealed that increased maternal prenatal negative life events were associated with higher child Negative Affectivity (β=0.08, P=0.009) but not with child Effortful Control (β=-0.03, P=0.39) or Surgency/Extraversion (β=0.04, P=0.14). Prenatal intakes of zinc and selenium modified this effect: Maternal exposure to prenatal negative life events was associated with higher child Negative Affectivity in the presence of lower intakes of zinc and selenium. Modification effects approached significance for vitamins A and C. The results suggest that the combination of elevated stress exposures and lower antioxidant intakes in pregnancy increases the likelihood of heightened child temperamental negative affectivity. Increased antioxidant intakes during pregnancy may protect against influences of prenatal stress on child temperament.
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11
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Duffy L, Bult-Ito A, Castillo M, Drew K, Harris M, Kuhn T, Ma Y, Schulte M, Taylor B, van Muelken M. Arctic Peoples and Beyond: research opportunities in neuroscience and behaviour. Int J Circumpolar Health 2016; 66:264-75. [PMID: 17655067 DOI: 10.3402/ijch.v66i3.18265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES Arctic and northern peoples are spread across Alaska, Canada, Russia and the Scandinavian countries. Inhabiting a variety of ecosystems, these 4 million residents include Indigenous populations who total about 10% of the population. Although Arctic peoples have very diverse cultural and social systems, they have health issues related to environmental impacts and knowledge/treatment disparities that are common to other minority and Indigenous peoples around the world. Research that explores the neuroscience and behavioural aspects of these health disparities offers challenges and significant opportunities. As the next generation of neuroscientists enter the field, it is imperative that they view their contributions in terms of translational medicine to address health disparities. STUDY DESIGN A workshop was designed to bring neuroscientists together to report on the current directions of neuroscience research and how it could impact health disparities in the North. This workshop produced research recommendations for the growth of neuroscience in the North. METHODS On May 31, 2006 the National Institute of Neurological Disorders and Stroke, the Burroughs Wellcome Foundation, the Arctic Division of AAAS and the University of Alaska co-sponsored a workshop entitled "Arctic Peoples and Beyond: Decreasing Health Disparities through Basic and Clinical Research." Also, the role and goals of the International Union for Circumpolar Health (IUCH) were presented at the meeting. RESULTS A set of recommendations related to research opportunities in neuroscience and behaviour research and ways to facilitate national and international partnerships were developed. CONCLUSIONS These recommendations should help guide the development of future health research in circumpolar neuroscience and behaviour. They provide ideas about research support and informational exchange that will address health challenges.
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Affiliation(s)
- Lawrence Duffy
- Specialized Neuroscience Research Program, University of Alaska Fairbanks, Fairbanks, Alaska 99775-6160, USA.
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12
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Bellinger DC, Matthews-Bellinger JA, Kordas K. A developmental perspective on early-life exposure to neurotoxicants. ENVIRONMENT INTERNATIONAL 2016; 94:103-112. [PMID: 27235688 DOI: 10.1016/j.envint.2016.05.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/14/2016] [Accepted: 05/14/2016] [Indexed: 05/24/2023]
Abstract
BACKGROUND Studies of early-life neurotoxicant exposure have not been designed, analyzed, or interpreted in the context of a fully developmental perspective. OBJECTIVES The goal of this paper is to describe the key principles of a developmental perspective and to use examples from the literature to illustrate the relevance of these principles to early-life neurotoxicant exposures. METHODS Four principles are discussed: 1) the effects of early-life neurotoxicant exposure depend on a child's developmental context; 2) deficits caused by early-life exposure initiate developmental cascades that can lead to pathologies that differ from those observed initially; 3) early-life neurotoxicant exposure has intra-familial and intergenerational impacts; 4) the impacts of early-life neurotoxicant exposure influence a child's ability to respond to future insults. The first principle is supported by considerable evidence, but the other three have received much less attention. DISCUSSION Incorporating a developmental perspective in studies of early-life neurotoxicant exposures requires prospective collection of data on a larger array of covariates than usually considered, using analytical approaches that acknowledge the transactional processes between a child and the environment and the phenomenon of developmental cascades. CONCLUSION Consideration of early-life neurotoxicant exposure within a developmental perspective reveals that many issues remain to be explicated if we are to achieve a deep understanding of the societal health burden associated with early-life neurotoxicant exposures.
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Affiliation(s)
- David C Bellinger
- Department of Neurology, Harvard Medical School, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02112, USA; Department of Psychiatry, Harvard Medical School, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA.
| | - Julia A Matthews-Bellinger
- Department of Psychiatry, University of Massachusetts Medical School, Boston Psychoanalytic Society and Institute, 19 Fair Oaks Park, Needham, MA 02492, USA.
| | - Katarzyna Kordas
- Department of Epidemiology and Environmental Health, University at Buffalo, 270 Farber Hall, Buffalo, NY 14214, USA.
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Brumberg HL, Shah SI. Born early and born poor: An eco-bio-developmental model for poverty and preterm birth. J Neonatal Perinatal Med 2016; 8:179-87. [PMID: 26485551 DOI: 10.3233/npm-15814098] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Poverty is associated with adverse long-term cognitive outcomes in children. Poverty is also linked with preterm delivery which, in turn, is associated with adverse cognitive outcomes. However, the extent of the effect of poverty on preterm delivery, as well as proposed mechanisms by which they occur, have not been well described. Further, the impact of poverty on preterm school readiness has not been reviewed. As the childhood poverty level continues to increase in the U.S., we examine the evidence around physiological, neurological, cognitive and learning outcomes associated with prematurity in the context of poverty. We use the evidence gathered to suggest an Eco-Bio-Developmental model, emphasizing poverty as a toxic stress which predisposes preterm birth and which, via epigenetic forces, can continue into the next generation. Continued postnatal social disadvantage for these developmentally high-risk preterm infants is strongly linked with poor neurodevelopmental outcomes, decreased school readiness, and decreased educational attainment which can perpetuate the poverty cycle. We suggest social remedies aimed at decreasing the impact of poverty on mothers, fathers, and children which may be effective in reducing the burden of preterm birth.
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Affiliation(s)
- H L Brumberg
- Division of Neonatology, The Regional Perinatal Center, Maria Fareri Children's Hospital at Westchester Medical Center, NY, USA
| | - S I Shah
- New York Medical College, Division of Neonatology, Maria Fareri Children's Hospital, NY, USA
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Fernández-Somoano A, Llop S, Aguilera I, Tamayo-Uria I, Martínez MD, Foraster M, Ballester F, Tardón A. Annoyance Caused by Noise and Air Pollution during Pregnancy: Associated Factors and Correlation with Outdoor NO2 and Benzene Estimations. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:7044-58. [PMID: 26095869 PMCID: PMC4483747 DOI: 10.3390/ijerph120607044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 05/29/2015] [Accepted: 06/15/2015] [Indexed: 11/16/2022]
Abstract
This study aimed to describe the degree of annoyance among pregnant women in a Spanish cohort and to examine associations with proximity to traffic, NO2 and benzene exposure. We included 2457 participants from the Spanish Childhood and Environment study. Individual exposures to outdoor NO2 and benzene were estimated, temporally adjusted for pregnancy. Interviews about sociodemographic variables, noise and air pollution were carried out. Levels of annoyance were assessed using a scale from 0 (none) to 10 (strong and unbearable); a level of 8 to 10 was considered high. The reported prevalence of high annoyance levels from air pollution was 11.2% and 15.0% from noise; the two variables were moderately correlated (0.606). Significant correlations between NO2 and annoyance from air pollution (0.154) and that from noise (0.181) were observed. Annoyance owing to noise and air pollution had a low prevalence in our Spanish population compared with other European populations. Both factors were associated with proximity to traffic. In multivariate models, annoyance from air pollution was related to NO2, building age, and country of birth; annoyance from noise was only related to the first two. The health burden of these exposures can be increased by stress caused by the perception of pollution sources.
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Affiliation(s)
- Ana Fernández-Somoano
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid 28029, Spain.
- Department of Preventive Medicine and Public Health, University of Oviedo, Asturias 33006, Spain.
| | - Sabrina Llop
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid 28029, Spain.
- Unit of Epidemiology and Environmental Health, FISABIO-Universitat Jaume I-Universitat de València Joint Research, Valencia 46020, Spain.
| | - Inmaculada Aguilera
- Swiss Tropical and Public Health Institute, Basel 4002, Switzerland.
- University of Basel, Basel 4003, Switzerland.
| | - Ibon Tamayo-Uria
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid 28029, Spain.
- Health Research Institute, Biodonostia, San Sebastián 20014, Spain.
| | - María Dolores Martínez
- Health Research Institute, Biodonostia, San Sebastián 20014, Spain.
- Department of Environment and Regional Planning, Basque Government, San Sebastian 20004, Spain.
| | - Maria Foraster
- Swiss Tropical and Public Health Institute, Basel 4002, Switzerland.
- University of Basel, Basel 4003, Switzerland.
- Centre for Research in Environmental Epidemiology (CREAL), Barcelona 08003, Spain.
- Hospital del Mar-Research Institute (IMIM), Barcelona 08003, Spain.
| | - Ferran Ballester
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid 28029, Spain.
- Unit of Epidemiology and Environmental Health, FISABIO-Universitat Jaume I-Universitat de València Joint Research, Valencia 46020, Spain.
| | - Adonina Tardón
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid 28029, Spain.
- Department of Preventive Medicine and Public Health, University of Oviedo, Asturias 33006, Spain.
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Schreier HMC, Hsu HH, Amarasiriwardena C, Coull BA, Schnaas L, Téllez-Rojo MM, Tamayo y Ortiz M, Wright RJ, Wright RO. Mercury and psychosocial stress exposure interact to predict maternal diurnal cortisol during pregnancy. Environ Health 2015; 14:28. [PMID: 25889585 PMCID: PMC4377006 DOI: 10.1186/s12940-015-0016-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 03/10/2015] [Indexed: 05/20/2023]
Abstract
BACKGROUND Disrupted maternal prenatal cortisol production influences offspring development. Factors influencing the hypothalamic-pituitary-adrenal axis include social (e.g., stressful life events) and physical/chemical (e.g., toxic metals) pollutants. Mercury (Hg) is a common contaminant of fish and exposure is widespread in the US. No prior study has examined the joint associations of stress and mercury with maternal cortisol profiles in pregnancy. OBJECTIVES To investigate potential synergistic influences of prenatal stress and Hg exposures on diurnal cortisol in pregnant women. METHODS Analyses included 732 women (aged 27.4 ± 5.6 years) from a Mexico City pregnancy cohort. Participants collected saliva samples on two consecutive days (mean 19.52 ± 3.00 weeks gestation) and reported life stressors over the past 6 months. Hg was assessed in toe nail clippings collected during pregnancy. RESULTS There were no main effects of Hg or psychosocial stress exposure on diurnal cortisol (ps > .20) but strong evidence of interaction effects on cortisol slope (interaction B = .006, SE = .003, p = .034) and cortisol at times 1 and 2 (interaction B = -.071, SE = .028, p = .013; B = -.078, SE = .032, p = .014). Women above the median for Hg and psychosocial stress exposure experienced a blunted morning cortisol response compared to women exposed to higher stress but lower Hg levels. CONCLUSIONS Social and physical environmental factors interact to alter aspects of maternal diurnal cortisol during pregnancy. Research focusing solely on either domain may miss synergistic influences with potentially important consequences to the offspring.
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Affiliation(s)
- Hannah M C Schreier
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1198, New York, NY, 10029, USA.
| | - Hsiao-Hsien Hsu
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Chitra Amarasiriwardena
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Brent A Coull
- Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA.
- Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA.
| | - Lourdes Schnaas
- Division of Research on Public Health, National Institute of Perinatology, Mexico City, Mexico.
| | - Martha María Téllez-Rojo
- Center for Evaluation Research and Surveys, National Institute of Public Health, Cuernavaca, Morelos, Mexico.
| | - Marcela Tamayo y Ortiz
- Center for Research in Nutrition and Health, National Institute of Public Health, Cuernavaca, Morelos, Mexico.
| | - Rosalind J Wright
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1198, New York, NY, 10029, USA.
| | - Robert O Wright
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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Sex-specific enhanced behavioral toxicity induced by maternal exposure to a mixture of low dose endocrine-disrupting chemicals. Neurotoxicology 2014; 45:121-30. [PMID: 25454719 DOI: 10.1016/j.neuro.2014.09.008] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 09/15/2014] [Accepted: 09/15/2014] [Indexed: 01/12/2023]
Abstract
Humans are increasingly and consistently exposed to a variety of endocrine disrupting chemicals (EDCs), chemicals that have been linked to neurobehavioral disorders such as ADHD and autism. Many of such EDCs have been shown to adversely influence brain mesocorticolimbic systems raising the potential for cumulative toxicity. As such, understanding the effects of developmental exposure to mixtures of EDCs is critical to public health protection. Consequently, this study compared the effects of a mixture of four EDCs to their effects alone to examine potential for enhanced toxicity, using behavioral domains and paradigms known to be mediated by mesocorticolimbic circuits (fixed interval (FI) schedule controlled behavior, novel object recognition memory and locomotor activity) in offspring of pregnant mice that had been exposed to vehicle or relatively low doses of four EDCs, atrazine (ATR - 10mg/kg), perfluorooctanoic acid (PFOA - 0.1mg/kg), bisphenol-A (BPA - 50 μg/kg), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD - 0.25 μg/kg) alone or combined in a mixture (MIX), from gestational day 7 until weaning. EDC-treated males maintained significantly higher horizontal activity levels across three testing sessions, indicative of delayed habituation, whereas no effects were found in females. Statistically significant effects of MIX were seen in males, but not females, in the form of increased FI response rates, in contrast to reductions in response rate with ATR, BPA and TCDD, and reduced short term memory in the novel object recognition paradigm. MIX also reversed the typically lower neophobia levels of males compared to females. With respect to individual EDCs, TCDD produced notable increases in FI response rates in females, and PFOA significantly increased ambulatory locomotor activity in males. Collectively, these findings show the potential for enhanced behavioral effects of EDC mixtures in males and underscore the need for animal studies to fully investigate mixtures, including chemicals that converge on common physiological substrates to examine potential mechanisms of toxicity with full dose effect curves to assist in interpretations of relevant mechanisms.
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Perspectives in Household Air Pollution Research: Who Will Benefit from Interventions? Curr Environ Health Rep 2014. [DOI: 10.1007/s40572-014-0021-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Searle AK, Baghurst PA, van Hooff M, Sawyer MG, Sim MR, Galletly C, Clark LS, McFarlane AC. Tracing the long-term legacy of childhood lead exposure: a review of three decades of the port Pirie cohort study. Neurotoxicology 2014; 43:46-56. [PMID: 24785378 DOI: 10.1016/j.neuro.2014.04.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 03/28/2014] [Accepted: 04/21/2014] [Indexed: 11/17/2022]
Abstract
Several prospective cohort studies have demonstrated that childhood lead levels show small but statistically significant adjusted associations with subsequent development in later childhood and adolescence. The Port Pirie Cohort study is one of the few prospective cohort studies to follow participants into adulthood. This paper reviews all childhood and adulthood findings of the Port Pirie Cohort study to date. Cohort members (initially, 723 infants born in/around the lead-smelting town of Port Pirie) showed a wide range of childhood blood lead levels, which peaked around 2 years old (M=21.3μg/dL, SD=1.2). At all childhood assessments, postnatal lead levels - particularly those reflecting cumulative exposure - showed small significant associations with outcomes including cognitive development, IQ, and mental health problems. While associations were substantially attenuated after adjusting for several childhood covariates, many remained statistically significant. Furthermore, average childhood blood lead showed small significant associations with some adult mental health problems for females, including anxiety problems and phobia, though associations only approached significance following covariate adjustment. Overall, there did not appear to be any age of greatest vulnerability or threshold of effect, and at all ages, females appeared more susceptible to lead-associated deficits. Together, these findings suggest that the associations between early childhood lead exposure and subsequent developmental outcomes may persist. However, as the magnitude of these effects was small, they are not discernible at the individual level, posing more of a population health concern. It appears that the combination of multiple early childhood factors best predicts later development. As such, minimising lead exposure in combination with improving other important early childhood factors such as parent-child interactions may be the best way to improve developmental outcomes.
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Affiliation(s)
- Amelia K Searle
- Centre for Traumatic Stress Studies, School of Population Health, University of Adelaide, South Australia 5000, Australia.
| | - Peter A Baghurst
- Discipline of Public Health, University of Adelaide, South Australia 5000, Australia; Discipline of Paediatrics, University of Adelaide, South Australia 5000, Australia
| | - Miranda van Hooff
- Centre for Traumatic Stress Studies, School of Population Health, University of Adelaide, South Australia 5000, Australia
| | - Michael G Sawyer
- Discipline of Paediatrics, University of Adelaide, South Australia 5000, Australia; Research and Evaluation Unit, Women's and Children's Health Network, South Australia 5000, Australia
| | - Malcolm R Sim
- Department of Epidemiology & Preventive Medicine, Monash University, Victoria 3004, Australia
| | - Cherrie Galletly
- Discipline of Psychiatry, University of Adelaide, South Australia 5000, Australia
| | - Levina S Clark
- Psychology Clinic, Flinders University, South Australia 5000, Australia
| | - Alexander C McFarlane
- Centre for Traumatic Stress Studies, School of Population Health, University of Adelaide, South Australia 5000, Australia
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Rossignol DA, Genuis SJ, Frye RE. Environmental toxicants and autism spectrum disorders: a systematic review. Transl Psychiatry 2014; 4:e360. [PMID: 24518398 PMCID: PMC3944636 DOI: 10.1038/tp.2014.4] [Citation(s) in RCA: 302] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 12/15/2013] [Accepted: 01/06/2014] [Indexed: 11/21/2022] Open
Abstract
Although the involvement of genetic abnormalities in autism spectrum disorders (ASD) is well-accepted, recent studies point to an equal contribution by environmental factors, particularly environmental toxicants. However, these toxicant-related studies in ASD have not been systematically reviewed to date. Therefore, we compiled publications investigating potential associations between environmental toxicants and ASD and arranged these publications into the following three categories: (a) studies examining estimated toxicant exposures in the environment during the preconceptional, gestational and early childhood periods; (b) studies investigating biomarkers of toxicants; and (c) studies examining potential genetic susceptibilities to toxicants. A literature search of nine electronic scientific databases through November 2013 was performed. In the first category examining ASD risk and estimated toxicant exposures in the environment, the majority of studies (34/37; 92%) reported an association. Most of these studies were retrospective case-control, ecological or prospective cohort studies, although a few had weaker study designs (for example, case reports or series). Toxicants implicated in ASD included pesticides, phthalates, polychlorinated biphenyls (PCBs), solvents, toxic waste sites, air pollutants and heavy metals, with the strongest evidence found for air pollutants and pesticides. Gestational exposure to methylmercury (through fish exposure, one study) and childhood exposure to pollutants in water supplies (two studies) were not found to be associated with ASD risk. In the second category of studies investigating biomarkers of toxicants and ASD, a large number was dedicated to examining heavy metals. Such studies demonstrated mixed findings, with only 19 of 40 (47%) case-control studies reporting higher concentrations of heavy metals in blood, urine, hair, brain or teeth of children with ASD compared with controls. Other biomarker studies reported that solvent, phthalate and pesticide levels were associated with ASD, whereas PCB studies were mixed. Seven studies reported a relationship between autism severity and heavy metal biomarkers, suggesting evidence of a dose-effect relationship. Overall, the evidence linking biomarkers of toxicants with ASD (the second category) was weaker compared with the evidence associating estimated exposures to toxicants in the environment and ASD risk (the first category) because many of the biomarker studies contained small sample sizes and the relationships between biomarkers and ASD were inconsistent across studies. Regarding the third category of studies investigating potential genetic susceptibilities to toxicants, 10 unique studies examined polymorphisms in genes associated with increased susceptibilities to toxicants, with 8 studies reporting that such polymorphisms were more common in ASD individuals (or their mothers, 1 study) compared with controls (one study examined multiple polymorphisms). Genes implicated in these studies included paraoxonase (PON1, three of five studies), glutathione S-transferase (GSTM1 and GSTP1, three of four studies), δ-aminolevulinic acid dehydratase (one study), SLC11A3 (one study) and the metal regulatory transcription factor 1 (one of two studies). Notably, many of the reviewed studies had significant limitations, including lack of replication, limited sample sizes, retrospective design, recall and publication biases, inadequate matching of cases and controls, and the use of nonstandard tools to diagnose ASD. The findings of this review suggest that the etiology of ASD may involve, at least in a subset of children, complex interactions between genetic factors and certain environmental toxicants that may act synergistically or in parallel during critical periods of neurodevelopment, in a manner that increases the likelihood of developing ASD. Because of the limitations of many of the reviewed studies, additional high-quality epidemiological studies concerning environmental toxicants and ASD are warranted to confirm and clarify many of these findings.
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Affiliation(s)
- D A Rossignol
- Family Medicine, Rossignol Medical Center, Irvine, CA, USA
| | - S J Genuis
- Faculty of Medicine, University of Alberta, Edmonton, AB, Canada
| | - R E Frye
- Arkansas Children's Hospital Research Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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20
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Sutton P, Woodruff TJ. Risk communication and decision tools for children's health protection. ACTA ACUST UNITED AC 2014; 99:45-9. [PMID: 23723171 DOI: 10.1002/bdrc.21029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 03/06/2013] [Indexed: 11/11/2022]
Abstract
Scientific discovery linking the environment to beneficial and adverse health children's health outcomes is rapidly expanding, leading scientists and health professionals to call for timely action to prevent harm and secure benefits. A robust method to synthesize what is known about the environmental drivers of health is a foundational step to making the science actionable by individuals and decision-makers. To meet this need, a methodology called the Navigation Guide was crafted by a collaboration of 22 clinical and environmental health scientists. The Navigation Guide proceeds from methods of research synthesis used in clinical settings but accounts for differences between environmental and clinical health sciences related to the evidence-base and decision-context. The methodology can be used to develop evidence profiles that provide simple, transparent summaries, such as practice guidelines or other evidence-based recommendations for prevention. Establishing proof-of-concept of the method is underway. Development of the Navigation Guide is extremely timely as it coincides with growing recognition of the need for updated methods in risk assessment. The costs in 2008 to the US healthcare system for treatment of childhood illnesses linked to toxic environmental exposures is conservatively estimated to be over $76 billion, and it is anticipated that US healthcare policy decisions will increasingly rely on systematic reviews of the evidence. The Navigation Guide is poised to provide a methodological bridge to link healthcare decision-making to efforts to reduce toxic environmental exposures. The institutionalization of the Navigation Guide would provide a concrete mechanism for linking science to action to protect children's health.
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Affiliation(s)
- Patrice Sutton
- Department of Obstetrics, Gynecology and Reproductive Sciences, Program on Reproductive Health and the Environment, University of California, San Francisco, Oakland, California 94162, USA.
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21
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Miller E, Valenti M. Healthy Environments Across Generations=Healthy Aging. Int J Aging Hum Dev 2014. [PMID: 26215302 DOI: 10.1177/0091415015591113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Elise Miller
- Collaborative on Health and the Environment (CHE), a program of Commonweal, Bolinas, CA, USA
| | - Maria Valenti
- Healthy Aging and Environment Initiative, Collaborative on Health and the Environment (CHE), a program of Commonweal, Bolinas, CA, USA
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22
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McFarlane AC, Searle AK, Van Hooff M, Baghurst PA, Sawyer MG, Galletly C, Sim MR, Clark LS. Prospective associations between childhood low-level lead exposure and adult mental health problems: The Port Pirie cohort study. Neurotoxicology 2013; 39:11-7. [DOI: 10.1016/j.neuro.2013.08.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 08/06/2013] [Accepted: 08/06/2013] [Indexed: 10/26/2022]
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Cohen Hubal EA, de Wet T, Du Toit L, Firestone MP, Ruchirawat M, van Engelen J, Vickers C. Identifying important life stages for monitoring and assessing risks from exposures to environmental contaminants: results of a World Health Organization review. Regul Toxicol Pharmacol 2013; 69:113-24. [PMID: 24099754 PMCID: PMC5355211 DOI: 10.1016/j.yrtph.2013.09.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 09/27/2013] [Indexed: 01/30/2023]
Abstract
We propose a harmonized set of age bins for assessing risks from chemical exposure. The set of early life age groups will facilitate consistency with recent guidance. The age bins allow results from longitudinal birth cohort studies to be combined. Region-specific exposure factors and monitoring data are needed to apply the bins.
In this paper, we summarize exposure-related issues to consider in determining the most appropriate age ranges and life stages for risk assessment. We then propose a harmonized set of age bins for monitoring and assessing risks from exposures to chemicals for global use. The focus is on preconception through adolescence, though the approach should be applicable to additional life stages. A two-tiered set of early life age groups is recommended. The first tier involves the adoption of guidance similar to the childhood age groups recommended by the U.S. Environmental Protection Agency, whereas the second tier consolidates some of those age groups to reduce the burden of developing age-specific exposure factors for different regions. While there is no single “correct” means of choosing a common set of age groups to use internationally in assessing early life exposure and risk, use of a set of defined age groups is recommended to facilitate comparisons of potential exposures and risks around the globe, the collection of data and analyses of aggregate exposure and cumulative risk. Application of these age groups for robust assessment of exposure and risk for specific populations will require region-specific exposure factors as well as local environmental monitoring data.
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Affiliation(s)
- Elaine A Cohen Hubal
- National Center for Computational Toxicology, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
| | - Thea de Wet
- Centre for Anthropological Research and Department of Anthropology and Development Studies, The University of Johannesburg, Auckland Park, South Africa.
| | - Lilo Du Toit
- Centre for Rural Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - Michael P Firestone
- Regulatory Support & Science Policy Division, Office of Children's Health Protection (MC 1107T), Office of the Administrator, U.S. Environmental Protection Agency, Room 1130 EPA West Building, 1200 Pennsylvania Avenue, N.W., Washington, DC 20460, USA.
| | - Mathuros Ruchirawat
- Office of Research, Chulabhorn Research Institute, 54 Kamphaeng-phet 6 Road, Laksi, Bangkok 10210, Thailand.
| | - Jacqueline van Engelen
- Center for Sustainability, Environment and Health, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands.
| | - Carolyn Vickers
- International Programme on Chemical Safety, World Health Organization, 20 Avenue Appia, CH-1211 Geneva 27, Switzerland.
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Abstract
This paper briefly reviews the social science on “neighborhood effects” as an independent force in shaping poor outcomes, specifically mental illness and criminal behavior, before discussing the implications of that research for understanding the relationship between neighborhoods, race and class. Neighborhood effects research has proliferated in recent years with extensive attention again being focused on the social context of family and individual development and life course. Moreover, recent work has suggested the need to consider the developmental effects of neighborhoods that persist across life-span. This paper will focus specifically on mental illness and criminal behavior as outcomes for understanding neighborhood effects, but will also consider what the structural causes of individual behavior and functioning mean for clinical assessment, especially forensic assessment.
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Affiliation(s)
- David Freedman
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA
| | - George W Woods
- Morehouse University School of Medicine, Atlanta, GA, USA
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25
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Kim Y, Ha EH, Park H, Ha M, Kim Y, Hong YC, Kim EJ, Kim BN. Prenatal lead and cadmium co-exposure and infant neurodevelopment at 6 months of age: The Mothers and Children's Environmental Health (MOCEH) study. Neurotoxicology 2013; 35:15-22. [DOI: 10.1016/j.neuro.2012.11.006] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Revised: 11/26/2012] [Accepted: 11/26/2012] [Indexed: 01/03/2023]
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Horton MK, Kahn LG, Perera F, Barr DB, Rauh V. Does the home environment and the sex of the child modify the adverse effects of prenatal exposure to chlorpyrifos on child working memory? Neurotoxicol Teratol 2012; 34:534-41. [PMID: 22824009 PMCID: PMC3901426 DOI: 10.1016/j.ntt.2012.07.004] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 07/10/2012] [Accepted: 07/16/2012] [Indexed: 11/20/2022]
Abstract
Prenatal exposure to chlorpyrifos (CPF), an organophosphorus insecticide, has long been associated with delayed neurocognitive development and most recently with decrements in working memory at age 7. In the current paper, we expanded the previous work on CPF to investigate how additional biological and social environmental factors might create or explain differential neurodevelopmental susceptibility, focusing on main and moderating effects of the quality of the home environment (HOME) and child sex. We evaluate how the quality of the home environment (specifically, parental nurturance and environmental stimulation) and child sex interact with the adverse effects of prenatal CPF exposure on working memory at child age 7years. We did not observe a remediating effect of a high quality home environment (either parental nurturance or environmental stimulation) on the adverse effects of prenatal CPF exposure on working memory. However, we detected a borderline significant interaction between prenatal exposure to CPF and child sex (B (95% CI) for interaction term=-1.714 (-3.753 to 0.326)) suggesting males experience a greater decrement in working memory than females following prenatal CPF exposure. In addition, we detected a borderline interaction between parental nurturance and child sex (B (95% CI) for interaction term=1.490 (-0.518 to 3.499)) suggesting that, in terms of working memory, males benefit more from a nurturing environment than females. To our knowledge, this is the first investigation into factors that may inform an intervention strategy to reduce or reverse the cognitive deficits resulting from prenatal CPF exposure.
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Affiliation(s)
- Megan K Horton
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY 10032, United States.
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Toxic environmental chemicals: the role of reproductive health professionals in preventing harmful exposures. Am J Obstet Gynecol 2012; 207:164-73. [PMID: 22405527 DOI: 10.1016/j.ajog.2012.01.034] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 01/24/2012] [Accepted: 01/24/2012] [Indexed: 11/24/2022]
Abstract
Every pregnant woman in the United States is exposed to many and varied environmental chemicals. Rapidly accumulating scientific evidence documents that widespread exposure to environmental chemicals at levels that are encountered in daily life can impact reproductive and developmental health adversely. Preconception and prenatal exposure to environmental chemicals are of particular importance because they may have a profound and lasting impact on health across the life course. Thus, prevention of developmental exposures to environmental chemicals would benefit greatly from the active participation of reproductive health professionals in clinical and policy arenas.
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Young GS, Fox MA, Trush M, Kanarek N, Glass TA, Curriero FC. Differential exposure to hazardous air pollution in the United States: a multilevel analysis of urbanization and neighborhood socioeconomic deprivation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2012; 9:2204-25. [PMID: 22829799 PMCID: PMC3397373 DOI: 10.3390/ijerph9062204] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Revised: 04/23/2012] [Accepted: 05/10/2012] [Indexed: 11/16/2022]
Abstract
Population exposure to multiple chemicals in air presents significant challenges for environmental public health. Air quality regulations distinguish criteria air pollutants (CAPs) (e.g., ozone, PM2.5) from hazardous air pollutants (HAPs)—187 chemicals which include carcinogens and others that are associated with respiratory, cardiovascular, neurological and numerous other non-cancer health effects. Evidence of the public’s cumulative exposure and the health effects of HAPs are quite limited. A multilevel model is used to assess differential exposure to HAP respiratory, neurological, and cancer hazards (2005) related to the Townsend Index of Socioeconomic Deprivation (TSI), after adjustment for regional population size and economic activity, and local population density. We found significant positive associations between tract TSI and respiratory and cancer HAP exposure hazards, and smaller effects for neurological HAPs. Tracts in the top quintile of TSI have between 38%–60% higher HAP exposure than the bottom quintile; increasing population size from the bottom quintile to the top quintile modifies HAP exposure hazard related to TSI, increasing cancer HAP exposure hazard by 6% to 20% and increasing respiratory HAP exposure hazard by 12% to 27%. This study demonstrates the value of social epidemiological methods for analyzing differential exposure and advancing cumulative risk assessment.
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Affiliation(s)
- Gary S. Young
- Department of Environmental Health Sciences, Johns Hopkins University, Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA; (M.T.); (N.K.); (F.C.C.)
- Author to whom correspondence should be addressed; ; Tel.: +1-856-986-3112; Fax: +1-856-342-3299
| | - Mary A. Fox
- Department of Health Policy and Management, Johns Hopkins University, Bloomberg School of Public Health, 624 N. Broadway, Baltimore, MD 21205, USA;
| | - Michael Trush
- Department of Environmental Health Sciences, Johns Hopkins University, Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA; (M.T.); (N.K.); (F.C.C.)
| | - Norma Kanarek
- Department of Environmental Health Sciences, Johns Hopkins University, Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA; (M.T.); (N.K.); (F.C.C.)
| | - Thomas A. Glass
- Department of Epidemiology, Johns Hopkins University, Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA;
| | - Frank C. Curriero
- Department of Environmental Health Sciences, Johns Hopkins University, Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA; (M.T.); (N.K.); (F.C.C.)
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Bellinger DC. A strategy for comparing the contributions of environmental chemicals and other risk factors to neurodevelopment of children. ENVIRONMENTAL HEALTH PERSPECTIVES 2012; 120:501-7. [PMID: 22182676 PMCID: PMC3339460 DOI: 10.1289/ehp.1104170] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 12/19/2011] [Indexed: 05/17/2023]
Abstract
BACKGROUND The impact of environmental chemicals on children's neurodevelopment is sometimes dismissed as unimportant because the magnitude of the impairments are considered to be clinically insignificant. Such a judgment reflects a failure to distinguish between individual and population risk. The population impact of a risk factor depends on both its effect size and its distribution (or incidence/prevalence). OBJECTIVE The objective was to develop a strategy for taking into account the distribution (or incidence/prevalence) of a risk factor, as well as its effect size, in order to estimate its population impact on neurodevelopment of children. METHODS The total numbers of Full-Scale IQ points lost among U.S. children 0-5 years of age were estimated for chemicals (methylmercury, organophosphate pesticides, lead) and a variety of medical conditions and events (e.g., preterm birth, traumatic brain injury, brain tumors, congenital heart disease). DISCUSSION Although the data required for the analysis were available for only three environmental chemicals (methylmercury, organophosphate pesticides, lead), the results suggest that their contributions to neurodevelopmental morbidity are substantial, exceeding those of many nonchemical risk factors. CONCLUSION A method for comparing the relative contributions of different risk factors provides a rational basis for establishing priorities for reducing neurodevelopmental morbidity in children.
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Affiliation(s)
- David C Bellinger
- Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts 02115 , USA.
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Weiss B. Synthetic food colors and neurobehavioral hazards: the view from environmental health research. ENVIRONMENTAL HEALTH PERSPECTIVES 2012; 120:1-5. [PMID: 21926033 PMCID: PMC3261946 DOI: 10.1289/ehp.1103827] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 09/16/2011] [Indexed: 05/28/2023]
Abstract
BACKGROUND The proposition that synthetic food colors can induce adverse behavioral effects in children was first enunciated in 1975 by Feingold [Why Your Child Is Hyperactive. New York:Random House (1975)], who asserted that elevated sensitivity to food additives underlies the signs of hyperactivity observed in some children. Although the evidence suggested that some unknown proportion of children did respond to synthetic food colors, the U.S. Food and Drug Administration (FDA) interpreted the evidence as inconclusive. A study published in 2007 [McCann et al. Food additives and hyperactive behaviour in 3-year-old and 8/9-year-old children in the community: a randomised, double-blinded, placebo-controlled trial. Lancet 370:1560-1567 (2007)] drew renewed attention to the hypothesis because of the study's size and scope. It led the FDA to review the evidence, hold a public hearing, and seek the advice of its Food Advisory Committee. In preparation for the hearing, the FDA reviewed the available evidence and concluded that it did not warrant further agency action. OBJECTIVES In this commentary I examine the basis of the FDA's position, the elements of the review that led to its decision and that of the Food Advisory Committee, and the reasons that this is an environmental health issue. DISCUSSION The FDA review confined itself, in essence, to the clinical diagnosis of hyperactivity, as did the charge to the committee, rather than asking the broader environmental question of behavioral effects in the general population; it failed to recognize the significance of vulnerable subpopulations; and it misinterpreted the meaning of effect size as a criterion of risk. The FDA's response would have benefited from adopting the viewpoints and perspectives common to environmental health research. At the same time, the food color debate offers a lesson to environmental health researchers; namely, too narrow a focus on a single outcome or criterion can be misleading.
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Affiliation(s)
- Bernard Weiss
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester, 601 Elmwood Ave., Rochester, NY 14642 USA.
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MacPhail RC, Farmer JD, Jarema KA. Toluene effects on the motor activity of adolescent, young-adult, middle-age and senescent male Brown Norway rats. Neurotoxicology 2011; 33:111-8. [PMID: 22192906 DOI: 10.1016/j.neuro.2011.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 12/08/2011] [Accepted: 12/08/2011] [Indexed: 11/25/2022]
Abstract
Life stage is an important risk factor for toxicity. Children and aging adults, for example, are more susceptible to certain chemicals than are young adults. In comparison to children, relatively little is known about susceptibility in older adults. Additionally, few studies have compared toxicant susceptibility across a broad range of life stages. Results are presented for behavioral evaluations of male Brown Norway rats obtained as adolescents (1 month), or young (4 months), middle-age (12 months) and senescent (24 months) adults. Motor activity was evaluated in photocell devices during 30-min sessions. Age-related baseline characteristics and sensitivity to toluene (0, 300, 650, or 1000mg/kg, p.o.) were determined. In Experiment 1, young-adult, middle-age and senescent rats were treated with corn-oil vehicle before five weekly test sessions. Baselines of horizontal and vertical activity decreased with age, but each age-group's averages remained stable across weeks of testing. Baseline activity of older rats was more variable than that of the young adults; older rats were also more variable individually from week to week. Toluene (1000mg/kg) increased horizontal activity proportionately more in senescent rats (ca. 300% of control) than in middle-age or young-adult rats (ca.145-175% of control). Experiment 2 established toluene dose-effect functions in individual adolescent, young-adult, middle-age and senescent rats; each rat received all treatments, counterbalanced across four weekly sessions. Toluene produced dose-related increases in horizontal activity that increased proportionately with age. Experiment 3 replicated the effects of toluene (1000mg/kg) in Experiment 1, showing that toluene-induced increases in horizontal activity were greatest in the oldest rats. Collectively, the results show that aging increased susceptibility to toluene and also increased variability in toluene response. Given the rapid growth of the aged population, further research is needed on aging-related susceptibility to environmental contaminants.
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Affiliation(s)
- R C MacPhail
- Neurotoxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
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Lee BK, Glass TA, James BD, Bandeen-Roche K, Schwartz BS. Neighborhood psychosocial environment, apolipoprotein E genotype, and cognitive function in older adults. ACTA ACUST UNITED AC 2011; 68:314-21. [PMID: 21383266 DOI: 10.1001/archgenpsychiatry.2011.6] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT The social environment may influence cognitive function in aging. However, to our knowledge, no studies have investigated whether specific genes modify this association. OBJECTIVE To examine whether the apolipoprotein E (APOE) ε4 allele modifies the association of neighborhood psychosocial hazards and cognitive function. DESIGN A cross-sectional analysis. SETTING The Baltimore Memory Study, a population-based sample of older urban residents. The 65 study neighborhoods in Baltimore, Maryland, were characterized using the Neighborhood Psychosocial Hazards Scale, designed to assess social disorganization, physical disorder, public safety, and economic deprivation. PARTICIPANTS One thousand one hundred forty urban residents aged 50 to 70 years at baseline. MAIN OUTCOME MEASURES Cognitive performance on 20 standard tests was measured and combined to form 7 summary domain scores (language, processing speed, eye-hand coordination, executive functioning, verbal memory and learning, visual memory, and visuoconstruction). RESULTS In analyses fully adjusted for individual covariates, we found that high (ie, worse) neighborhood psychosocial hazards were not consistently associated with worse cognitive performance. However, the interaction of high neighborhood psychosocial hazards and APOE ε4 genotype was found to be associated with worse cognitive domain scores, with evidence of associations in the domains of processing speed (P = .02) and executive functioning (P < .001). Suggestive evidence was also found for eye-hand coordination (P = .05). CONCLUSION Living in a psychosocially hazardous neighborhood was associated with worse cognitive function in persons with the APOE ε4 allele, evidence of a novel gene × environment interaction.
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Affiliation(s)
- Brian K Lee
- Department of Epidemiology and Biostatistics, Drexel University School of Public Health, Philadelphia, Pennsylvania, USA.
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Freire C, Amaya E, Fernández MF, González-Galarzo MC, Ramos R, Molina-Molina JM, Arrebola JP, Olea N. Relationship between occupational social class and exposure to organochlorine pesticides during pregnancy. CHEMOSPHERE 2011; 83:831-838. [PMID: 21435678 DOI: 10.1016/j.chemosphere.2011.02.076] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 01/26/2011] [Accepted: 02/27/2011] [Indexed: 05/30/2023]
Abstract
BACKGROUND Little evidence is available on the influence of socioeconomic factors on exposure to persistent organic pollutants, especially during vulnerable periods such as pregnancy and early life. OBJECTIVE To investigate the relationship of maternal social class with placental concentrations of organochlorine pesticides (OCPs) and their combined estrogenic activity measured with a biomarker of exposure. METHODS Exposure to 16 OCPs (DDTs, endosulfans, and seven other compounds) and the total effective xenoestrogenic burden (TEXB) were analyzed in placentas from a mother-child cohort. OCP concentrations were quantified by gas chromatography and mass spectrometry, and TEXB was assessed with the E-Screen bioassay. Social class was classified according to maternal occupation. Multivariate regression analysis was conducted to examine variations in pesticide exposure and TEXB as a function of maternal social class in 257 subjects. RESULTS Placental p,p'-DDT concentrations were higher in social classes III and IV than in classes I-II (the most affluent); concentrations of the sum of DDTs were higher in class IV; and exposure to the sum of endosulfans was greater in class III. HCB concentrations were higher among women in class IV than in classes I-II and among manual (classes III-V) than non-manual workers. However, the trend across social classes was only statistically significant for HCB. Social class significantly explained 10% of the variability in concentrations of the sum of endosulfans. CONCLUSION There is a need to explore whether more disadvantaged populations suffer higher levels of exposure to pesticides or other environmental chemicals and how different social processes contribute to this exposure.
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Affiliation(s)
- Carmen Freire
- Laboratory of Medical Investigations, San Cecilio University Hospital, University of Granada, CIBER de Epidemiología y Salud Pública (CIBERESP), Av. Madrid s/n, 18071 Granada, Spain.
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Clougherty JE, Kubzansky LD. A framework for examining social stress and susceptibility to air pollution in respiratory health. CIENCIA & SAUDE COLETIVA 2010; 15:2059-74. [PMID: 20694328 DOI: 10.1590/s1413-81232010000400020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Accepted: 05/12/2009] [Indexed: 12/30/2022] Open
Abstract
There is growing interest in disentangling the health effects of spatially clustered social and physical environmental exposures and in exploring potential synergies among them, with particular attention directed to the combined effects of psychosocial stress and air pollution. Both exposures may be elevated in lower-income urban communities, and it has been hypothesized that stress, which can influence immune function and susceptibility, may potentiate the effects of air pollution in respiratory disease onset and exacerbation. In this paper, we review the existing epidemiologic and toxicologic evidence on synergistic effects of stress and pollution, and describe the physiologic effects of stress and key issues related to measuring and evaluating stress as it relates to physical environmental exposures and susceptibility. Finally, we identify some of the major methodologic challenges ahead as we work toward disentangling the health effects of clustered social and physical exposures and accurately describing the interplay among these exposures. As this research proceeds, we recommend careful attention to the relative temporalities of stress and pollution exposures, to nonlinearities in their independent and combined effects, to physiologic pathways not elucidated by epidemiologic methods, and to the relative spatial distributions of social and physical exposures at multiple geographic scales.
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Affiliation(s)
- Jane Ellen Clougherty
- Department of Environmental Health, Harvard School of Public Health, Boston, MA 02215, USA.
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Olympio KPK, Naozuka J, Oliveira PV, Cardoso MRA, Bechara EJH, Günther WMR. Association of dental enamel lead levels with risk factors for environmental exposure. Rev Saude Publica 2010; 44:851-8. [DOI: 10.1590/s0034-89102010000500010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Accepted: 03/03/2010] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVE: To analyze household risk factors associated with high lead levels in surface dental enamel. METHODS: A cross-sectional study was conducted with 160 Brazilian adolescents aged 14-18 years living in poor neighborhoods in the city of Bauru, southeastern Brazil, from August to December 2008. Body lead concentrations were assessed in surface dental enamel acid-etch microbiopsies. Dental enamel lead levels were measured by graphite furnace atomic absorption spectrometry and phosphorus levels were measured by inductively coupled plasma optical emission spectrometry. The parents answered a questionnaire about their children's potential early (05 years old) exposure to well-known lead sources. Logistic regression was used to identify associations between dental enamel lead levels and each environmental risk factor studied. Social and familial covariables were included in the models. RESULTS: The results suggest that the adolescents studied were exposed to lead sources during their first years of life. Risk factors associated with high dental enamel lead levels were living in or close to a contaminated area (OR = 4.49; 95% CI: 1.69;11.97); and member of the household worked in the manufacturing of paints, paint pigments, ceramics or batteries (OR = 3.43; 95% CI: 1.31;9.00). Home-based use of lead-glazed ceramics, low-quality pirated toys, anticorrosive paint on gates and/or sale of used car batteries (OR = 1.31; 95% CI: 0.56;3.03) and smoking (OR = 1.66; 95% CI: 0.52;5.28) were not found to be associated with high dental enamel lead levels. CONCLUSIONS: Surface dental enamel can be used as a marker of past environmental exposure to lead and lead concentrations detected are associated to well-known sources of lead contamination.
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Weiss B. Same sex, no sex, and unaware sex in neurotoxicology. Neurotoxicology 2010; 32:509-17. [PMID: 20875453 DOI: 10.1016/j.neuro.2010.09.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 09/19/2010] [Accepted: 09/20/2010] [Indexed: 11/16/2022]
Abstract
Males and females of virtually all species differ in how they respond to their environment. Because such differences exist in almost all biological realms, including disease patterns and therapeutic outcomes, they have evoked calls by various bodies to incorporate their assessment in research. Neurobehavioral indices pose special questions because, unlike outwardly visible markers, they are described by complex functional outcomes or subtle alterations in brain structure. These divergent responses arise because they are inscribed in the genome itself and then by endocrine mechanisms that govern sexual differentiation of the brain during development and operate throughout life. Other organ systems that exhibit sex differences include the liver, an important consideration for neurotoxicology because it may process many toxic chemicals differentially in males and females. Despite the scope and pervasiveness of sex differences, however, they are disregarded by much of neurotoxicology research. Males predominate in behavioral experiments, few such experiments study both sexes, some investigators fail to even describe the sex of their subjects, and in vitro studies tend to wholly ignore sex, even for model systems aimed at neurological disorders that display marked sex differences. The public is acutely aware of sex differences in behavior, as attested by its appetite for books on the topic. It closely follows debates about the proportion of women in professions that feature science and mathematics. Neurotoxicology, especially in the domain of laboratory research, will be hindered in its ability to translate its findings into human health measures if it assigns sex differences to a minor role. It must also be sensitive to how such debates are framed. Often, the differences evoking the most discussion are subtle in scope. They do not lend themselves to the typical analyses conducted by experimenters; that is, reliance on mean differences and null hypothesis testing.
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Affiliation(s)
- Bernard Weiss
- Department of Environmental Medicine, University of Rochester, School of Medicine and Dentistry, Rochester, NY 14642, United States.
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Gilbert SG, Miller E, Martin J, Abulafia L. Scientific and policy statements on environmental agents associated with neurodevelopmental disorders. JOURNAL OF INTELLECTUAL & DEVELOPMENTAL DISABILITY 2010; 35:121-128. [PMID: 20560701 DOI: 10.3109/13668251003717563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Given established scientific knowledge, protecting children from neurotoxic exposures from the earliest stages of fetal development is clearly an essential public health measure. By reducing environmental factors that may lead to learning and developmental disorders, we will create a healthier environment in which all children can reach and maintain their full potential. (Gilbert, 2008 ).
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Affiliation(s)
- Steven G Gilbert
- Institute of Neurotoxicology and Neurological Disorders, Seattle, WA 98115, USA.
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Clougherty JE, Rossi CA, Lawrence J, Long MS, Diaz EA, Lim RH, McEwen B, Koutrakis P, Godleski JJ. Chronic social stress and susceptibility to concentrated ambient fine particles in rats. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:769-75. [PMID: 20194079 PMCID: PMC2898852 DOI: 10.1289/ehp.0901631] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Accepted: 03/01/2010] [Indexed: 05/23/2023]
Abstract
BACKGROUND Epidemiologic evidence suggests that chronic stress may alter susceptibility to air pollution. However, persistent spatial confounding between these exposures may limit the utility of epidemiologic methods to disentangle these effects and cannot identify physiologic mechanisms for potential differential susceptibilities. OBJECTIVES Using a rat model of social stress, we compared respiratory responses to fine concentrated ambient particles (CAPs) and examined biological markers of inflammation. METHODS Twenty-four 12-week-old male Sprague-Dawley rats were randomly assigned to four groups [stress/CAPs, stress/filtered air (FA), nonstress/CAPs, nonstress/FA]. Stress-group animals were individually introduced into the home cage of a dominant male twice weekly. Blood drawn at sacrifice was analyzed for immune and inflammatory markers. CAPs were generated using the Harvard ambient particle concentrator, which draws real-time urban ambient fine particles, enriching concentrations approximately 30 times. CAPs/FA exposures were delivered in single-animal plethysmographs, 5 hr/day for 10 days, and respiratory function was continuously monitored using a Buxco system. RESULTS Stressed animals displayed higher average C-reactive protein, tumor necrosis factor-alpha, and white blood cell counts than did nonstressed animals. Only among stressed animals were CAPs exposures associated with increased respiratory frequency, lower flows, and lower volumes, suggesting a rapid, shallow breathing pattern. Conversely, in animals with elevated CAPs exposures alone, we observed increased inspiratory flows and greater minute volumes (volume of air inhaled or exhaled per minute). CONCLUSIONS CAPs effects on respiratory measures differed significantly, and substantively, by stress group. Higher CAPs exposures were associated with a rapid, shallow breathing pattern only under chronic stress. Blood measures provided evidence of inflammatory responses. Results support epidemiologic findings that chronic stress may alter respiratory response to air pollution and may help elucidate pathways for differential susceptibility.
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Affiliation(s)
- Jane E Clougherty
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts 02215, USA.
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Sanchez YA, Deener K, Hubal EC, Knowlton C, Reif D, Segal D. Research needs for community-based risk assessment: findings from a multi-disciplinary workshop. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2010; 20:186-195. [PMID: 19240762 DOI: 10.1038/jes.2009.8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Accepted: 12/29/2008] [Indexed: 05/27/2023]
Abstract
Communities face exposures to multiple environmental toxicants and other non-chemical stressors. In addition, communities have unique activities and norms that influence exposure and vulnerability. Yet, few studies quantitatively consider the role of cumulative exposure and additive impacts. Community-based risk assessment (CBRA) is a new approach for risk assessment that aims to address the cumulative stressors faced by a particular community, while incorporating a community-based participatory research framework. This paper summarizes an Environmental Protection Agency (EPA) sponsored workshop, "Research Needs for Community-Based Risk Assessment." This workshop brought together environmental and public health scientists and practitioners for fostering an innovative discussion about tools, methods, models, and approaches for CBRA. This workshop was organized around three topics: (1) Data and Measurement Methods; (2) The Biological Impact of Non-Chemical Stressors and Interaction with Environmental Exposures; and (3) Statistical and Mathematical Modeling. This report summarizes the workshop discussions, presents identified research needs, and explores future research opportunities in this emerging field.
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Abstract
BACKGROUND The current population of older Americans has accumulated substantial lifetime lead doses, which raises concern about the possibility of adverse cognitive outcomes. We evaluated whether cumulative lead dose from environmental exposures is associated with cognitive function and decline, and whether such effects are persistent, reversible, or progressive. METHODS We used longitudinal linear modeling to evaluate associations of tibia lead concentration with cognitive function and decline in sociodemographically diverse, community-dwelling adults aged 50-70 years who were randomly selected from neighborhoods in Baltimore. Six summary measures of cognitive function were created from standard tests in the following domains: language, processing speed, eye-hand coordination, executive functioning, verbal memory and learning, and visual memory. RESULTS The mean (SD) tibia lead level was 18.8 (11.6) microg/g. In models adjusted for demographic characteristics, socioeconomic status (SES), and race/ethnicity, higher tibia lead was associated with a progressive decline in eye-hand coordination. Tibia lead was associated with persistently impaired cognitive function in all 6 domains, although these associations weakened after increasing covariate control. In fully adjusted stratified analysis among white persons, persistent effects were apparent in eye-hand coordination, executive functioning, and verbal memory and learning. CONCLUSIONS The study presents the strongest evidence to date of the effects of cumulative lead dose on adult cognitive function independent of SES. The study population was relatively young and the average total duration of follow-up short (<30 months); these findings may represent the lower bound of the impact of cumulative lead dose on cognitive function of older adults.
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Olympio KPK, Oliveira PV, Naozuka J, Cardoso MRA, Marques AF, Günther WMR, Bechara EJH. Surface dental enamel lead levels and antisocial behavior in Brazilian adolescents. Neurotoxicol Teratol 2009; 32:273-9. [PMID: 20005947 DOI: 10.1016/j.ntt.2009.12.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2009] [Revised: 11/24/2009] [Accepted: 12/07/2009] [Indexed: 10/20/2022]
Abstract
Lead poisoning has been reportedly linked to a high risk of learning disabilities, aggression and criminal offenses. To study the association between lead exposure and antisocial/delinquent behavior, a cross-sectional study was conducted with 173 Brazilian youths aged 14-18 and their parents (n=93), living in impoverished neighborhoods of Bauru-SP, with high criminality indices. Self-Reported Delinquency (SRD) and Child Behavior Checklist (CBCL) questionnaires were used to evaluate delinquent/antisocial behavior. Body lead burdens were evaluated in surface dental enamel acid microbiopsies. The dental enamel lead levels (DELL) were quantified by graphite furnace atomic absorption spectrometry (GFAAS) and phosphorus content was measured using inductively coupled plasma optical emission spectrometry (ICP-OES). Logistic regression was used to identify associations between DELL and each scale defined by CBCL and SRD scores. Odd ratios adjusted for familial and social covariates, considering a group of youths exposed to high lead levels (>or=75 percentile), indicated that high DELL is associated with increased risk of exceeding the clinical score for somatic complaints, social problems, rule-breaking behavior and externalizing problems (CI 95%). High DELL was not found to be associated with elevated SRD scores. In conclusion, our data support the hypothesis that high-level lead exposure can trigger antisocial behavior, which calls for public policies to prevent lead poisoning.
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Affiliation(s)
- Kelly P K Olympio
- Faculdade de Saúde Pública, Departamento de Saúde Ambiental, Universidade de São Paulo, 01246-904 São Paulo, Brazil
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Suglia SF, Franco Suglia S, Duarte CS, Sandel MT, Wright RJ. Social and environmental stressors in the home and childhood asthma. J Epidemiol Community Health 2009; 64:636-42. [PMID: 19828512 DOI: 10.1136/jech.2008.082842] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Both physical environmental factors and chronic stress may independently increase susceptibility to asthma; however, little is known on how these different risks may interact. The authors examined the relationship between maternal intimate partner violence (IPV), housing quality and asthma among children in the Fragile Families and Child Wellbeing Study (N=2013). METHODS Maternal reports of IPV were obtained after the child's birth and at 12 and 36 months. At the 36-month assessment, interviewers rated indoor housing conditions, regarding housing deterioration (ie, peeling paint, holes in floor, broken windows) and housing disarray (ie, dark, cluttered, crowded or noisy house). At the same time, mothers reported on housing hardships (ie, moving repeatedly, and hardships in keeping house warm). Maternal-report of physician-diagnosed asthma by age 36 months which was active in the past year was the outcome. RESULTS Asthma was diagnosed in 10% of the children. In an adjusted analysis, an increased odds of asthma was observed in children of mothers experiencing IPV chronically (OR 1.8, 95% CI 1.0 to 3.5) and in children experiencing housing disarray (OR 1.5, 95% CI 1.1 to 2.0) compared with those not exposed to these risks. In stratified analyses, a greater effect of IPV on asthma was noted among children living in disarrayed or deteriorated housing or among children whose mothers were experiencing housing hardship. CONCLUSIONS IPV and housing disarray are associated with increased early childhood asthma. Exposure to cumulative or multiple stressors (ie, IPV and poor housing quality) may increase children's risk of developing asthma more than a single stressor.
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Affiliation(s)
- Shakira Franco Suglia
- Department of Pediatrics, Boston University School of Medicine, 88 East Newton Street, Boston, MA 02118, USA.
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Clougherty JE, Kubzansky LD. A framework for examining social stress and susceptibility to air pollution in respiratory health. ENVIRONMENTAL HEALTH PERSPECTIVES 2009; 117:1351-8. [PMID: 19750097 PMCID: PMC2737009 DOI: 10.1289/ehp.0900612] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Accepted: 05/12/2009] [Indexed: 05/18/2023]
Abstract
OBJECTIVE There is growing interest in disentangling the health effects of spatially clustered social and physical environmental exposures and in exploring potential synergies among them, with particular attention directed to the combined effects of psychosocial stress and air pollution. Both exposures may be elevated in lower-income urban communities, and it has been hypothesized that stress, which can influence immune function and susceptibility, may potentiate the effects of air pollution in respiratory disease onset and exacerbation. In this paper, we attempt to synthesize the relevant research from social and environmental epidemiology, toxicology, immunology, and exposure assessment to provide a useful framework for environmental health researchers aiming to investigate the health effects of environmental pollution in combination with social or psychological factors. DATA SYNTHESIS We review the existing epidemiologic and toxicologic evidence on synergistic effects of stress and pollution, and then describe the physiologic effects of stress and key issues related to measuring and evaluating stress as it relates to physical environmental exposures and susceptibility. Finally, we identify some of the major methodologic challenges ahead as we work toward disentangling the health effects of clustered social and physical exposures and accurately describing the interplay among these exposures. CONCLUSIONS There is still tremendous work to be done toward understanding the combined and potentially synergistic health effects of stress and pollution. As this research proceeds, we recommend careful attention to the relative temporalities of stress and pollution exposures, to nonlinearities in their independent and combined effects, to physiologic pathways not elucidated by epidemiologic methods, and to the relative spatial distributions of social and physical exposures at multiple geographic scales.
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Affiliation(s)
- Jane E Clougherty
- Department of Environmental Health, Harvard School of Public Health, Boston, MA 02215, USA.
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Kosa K, Darago L, Adany R. Environmental survey of segregated habitats of Roma in Hungary: a way to be empowering and reliable in minority research. Eur J Public Health 2009; 21:463-8. [DOI: 10.1093/eurpub/ckp097] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Bellinger DC. Interpreting epidemiologic studies of developmental neurotoxicity: conceptual and analytic issues. Neurotoxicol Teratol 2009; 31:267-74. [PMID: 19595760 DOI: 10.1016/j.ntt.2009.06.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 06/20/2009] [Accepted: 06/25/2009] [Indexed: 11/25/2022]
Abstract
This paper discusses issues pertaining to the validity, precision, and interpretation of epidemiologic studies of neurotoxicity. With regard to validity, the critical issues pertain to the appropriate strategy for confounder adjustment, particularly when confounders are complex, multi-faceted constructs, and to the need for greater clarity and transparency in articulating the causal relationships implicit in the analytic approach applied. With regard to precision, the critical issue is a need to identify the contributors to the substantial variability observed in the effect estimates that describe dose-response and dose-effect relationships. In addition to methodological sources, such as imprecision in estimating dose at the critical organ site(s), true inter-individual differences in susceptibility to a neurotoxicant could also contribute to the variability. Variability might be reduced by taking full account of factors such as co-exposures or health co-morbidities, genetic polymorphisms, and the social ecology of exposure. With regard to interpretation, we need to do a better job as a field conveying to risk assessors and others the ecological significance of the types of performance deficits observed following neurotoxicant exposure, emphasizing the distinction between individual and population risk. A final issue discussed is the need to define standards for the conduct, analysis, and reporting of epidemiologic studies of neurotoxicity, similar to those developed for other fields.
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Affiliation(s)
- David C Bellinger
- Children's Hospital Boston, Harvard Medical School, Harvard School of Public Health, Farley Basement Box 127, Children's Hospital, Boston, MA 02115, USA.
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Slotkin TA, Lassiter TL, Ryde IT, Wrench N, Levin ED, Seidler FJ. Consumption of a high-fat diet in adulthood ameliorates the effects of neonatal parathion exposure on acetylcholine systems in rat brain regions. ENVIRONMENTAL HEALTH PERSPECTIVES 2009; 117:916-22. [PMID: 19590683 PMCID: PMC2702406 DOI: 10.1289/ehp.0800459] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Accepted: 02/03/2009] [Indexed: 05/08/2023]
Abstract
BACKGROUND Developmental exposure to a wide variety of developmental neurotoxicants, including organophosphate pesticides, evokes late-emerging and persistent abnormalities in acetylcholine (ACh) systems. We are seeking interventions that can ameliorate or reverse the effects later in life. OBJECTIVES We administered parathion to neonatal rats and then evaluated whether a high-fat diet begun in adulthood could reverse the effects on ACh systems. METHODS Neonatal rats received parathion on postnatal days 1-4 at 0.1 or 0.2 mg/kg/day, straddling the cholinesterase inhibition threshold. In adulthood, half the animals were switched to a high-fat diet for 8 weeks. We assessed three indices of ACh synaptic function: nicotinic ACh receptor binding, choline acetyltransferase activity, and hemicholinium-3 binding. Determinations were performed in brain regions comprising all the major ACh projections and cell bodies. RESULTS Neonatal parathion exposure evoked widespread abnormalities in ACh synaptic markers, encompassing effects in brain regions possessing ACh projections and ACh cell bodies. In general, males were affected more than females. Of 17 regional ACh marker abnormalities (10 male, 7 female), 15 were reversed by the high-fat diet. CONCLUSIONS A high-fat diet reverses neurodevelopmental effects of neonatal parathion exposure on ACh systems. This points to the potential for nonpharmacologic interventions to offset the effects of developmental neurotoxicants. Further, cryptic neurodevelopmental deficits evoked by environmental exposures may thus engender a later preference for a high-fat diet to maintain normal ACh function, ultimately contributing to obesity.
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Affiliation(s)
- Theodore A Slotkin
- Department of Pharmacology & Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA.
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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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Hirsch HVB, Possidente D, Averill S, Despain TP, Buytkins J, Thomas V, Goebel WP, Shipp-Hilts A, Wilson D, Hollocher K, Possidente B, Lnenicka G, Ruden DM. Variations at a quantitative trait locus (QTL) affect development of behavior in lead-exposed Drosophila melanogaster. Neurotoxicology 2009; 30:305-11. [PMID: 19428504 DOI: 10.1016/j.neuro.2009.01.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 12/31/2008] [Accepted: 01/12/2009] [Indexed: 12/01/2022]
Abstract
We developed Drosophila melanogaster as a model to study correlated behavioral, neuronal and genetic effects of the neurotoxin lead, known to affect cognitive and behavioral development in children. We showed that, as in vertebrates, lead affects both synaptic development and complex behaviors (courtship, fecundity, locomotor activity) in Drosophila. By assessing differential behavioral responses to developmental lead exposure among recombinant inbred Drosophila lines (RI), derived from parental lines Oregon R and Russian 2b, we have now identified a genotype by environment interaction (GEI) for a behavioral trait affected by lead. Drosophila Activity Monitors (TriKinetics, Waltham, MA), which measure activity by counting the number of times a single fly in a small glass tube walks through an infrared beam aimed at the middle of the tube, were used to measure activity of flies, reared from eggs to 4 days of adult age on either control or lead-contaminated medium, from each of 75 RI lines. We observed a significant statistical association between the effect of lead on Average Daytime Activity (ADA) across lines and one marker locus, 30AB, on chromosome 2; we define this as a Quantitative Trait Locus (QTL) associated with behavioral effects of developmental lead exposure. When 30AB was from Russian 2b, lead significantly increased locomotor activity, whereas, when 30AB was from Oregon R, lead decreased it. 30AB contains about 125 genes among which are likely "candidate genes" for the observed lead-dependent behavioral changes. Drosophila are thus a useful, underutilized model for studying behavioral, synaptic and genetic changes following chronic exposure to lead or other neurotoxins during development.
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Affiliation(s)
- Helmut V B Hirsch
- Department of Biology, University at Albany, SUNY, Albany, NY 12222, USA.
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Rice DC. Overview of modifiers of methylmercury neurotoxicity: chemicals, nutrients, and the social environment. Neurotoxicology 2008; 29:761-6. [PMID: 18722469 DOI: 10.1016/j.neuro.2008.07.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Revised: 06/26/2008] [Accepted: 07/07/2008] [Indexed: 10/21/2022]
Abstract
It has been known for decades that methylmercury is a potent neurotoxicant, and that the developing brain is more susceptible to impairment as a result of methylmercury exposure than is the adult. Exposure to methylmercury is exclusively through consumption of fish and marine mammals. In recent years, the potential for protection against methylmercury toxicity by nutrients present in fish, particularly omega-3 fatty acids and selenium, has been explored in both epidemiological and experimental studies. There is evidence from several studies that fish consumption per se and methylmercury body burden act in opposition with regard to neuropsychological outcomes, whereas the evidence for a protective effect of specific nutrients is contradictory in both epidemiological and experimental studies published to date. The potential for methylmercury to interact with other chemicals present in marine food, particularly PCBs, has been explored in both animal models and human studies. Results may be both exposure- and endpoint-dependent. The Seychelles Islands study has explored the potential for the social environment to modify the effects of developmental methylmercury exposure. An understanding of the interactions of the multiple factors that determine the final behavioral outcome of exposure to methylmercury is crucial to risk assessment and risk management decisions.
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Affiliation(s)
- Deborah C Rice
- Maine Center for Disease Control and Prevention, Augusta, ME 04333, United States.
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Abstract
Recent research shows that exposure to community violence is, directly and indirectly, associated with asthma. This article reviews the findings on the impact of violence on asthma, and the pathways for the association of violence and asthma are suggested: 1) exposure to violence is directly associated with asthma, mainly through dysregulation of sympathetic-adrenal-medullary (SAM) and hypothalamic-pituitary-adrenal (HPA) axis, 2) exposure to violence is associated with the change of susceptibility of outdoor air pollution on asthma, probably through the change of an immune response, and 3) behavioral change due to exposure to violence (e.g. keeping children indoors) leads to more exposure to indoor pollutants. The suggested framework may be useful to develop health policy on asthma in high-violence communities.
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Affiliation(s)
- Takeo Fujiwara
- Department of Health Promotion and Research, National Institute of Public Health, Wako-shi, Saitama, Japan
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