Environmental Toxins Research: Childhood Exposure

In-home toxic chemical exposures and children with intellectual and developmental disabilities.

Graff JC, Murphy L, Ekvall S, Gagnon M.  Boling Center for Developmental Disabilities, College of Nursing, University of Tennessee Health Science Center, Memphis, USA.  Pediatr Nurs. 2006 Nov-Dec;32(6):596-603.

Despite the focus on preventing toxic chemical exposures during pregnancy, the perinatal period, and childhood, health professionals have given little attention to the risks and effects of toxic chemical exposures on children with intellectual and developmental disabilities (DD). Children with DD may be at higher risk due to behaviors that persist past a developmentally appropriate age, communication skills, motor skills, nutrition issues, and health problems related to DD. This article examines exposure of children to lead, mercury, and environmental tobacco smoke, three toxicants known to affect children’s health and development. The authors identify sources of these toxicants, examine research documenting their effects on children, consider strategies to prevent and manage exposure, identify characteristics and behaviors placing children with DD at increased risk of exposure, and discuss implications for health providers.


Lessons learned for the National Children’s Study from the National Institute of Environmental Health Sciences/U.S. Environmental Protection Agency Centers for Children’s Environmental Health and Disease Prevention Research.

Kimmel CA, Collman GW, Fields N, Eskenazi B.  National Children’s Study Interagency Coordinating Committee, National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC, USA.  Environ Health Perspect. 2005 Oct;113(10):1414-8.

This mini-monograph was developed to highlight the experiences of the National Institute of Environmental Health Sciences (NIEHS)/U.S. Environmental Protection Agency (EPA) Centers for Children’s Environmental Health and Disease Prevention Research, focusing particularly on several areas of interest for the National Children’s Study. These include general methodologic issues for conducting longitudinal birth cohort studies and community-based participatory research and for measuring air pollution exposures, pesticide exposures, asthma, and neurobehavioral toxicity. Rather than a detailed description of the studies in each of the centers, this series of articles is intended to provide information on the practicalities of conducting such intensive studies and the lessons learned. This explication of lessons learned provides an outstanding opportunity for the planners of the National Children’s Study to draw on past experiences that provide information on what has and has not worked when studying diverse multiracial and multiethnic groups of children with unique urban and rural exposures. The Children’s Centers have addressed and overcome many hurdles in their efforts to understand the link between environmental exposures and health outcomes as well as interactions between exposures and a variety of social and cultural factors. Some of the major lessons learned include the critical importance of long-term studies for assessing the full range of developmental consequences of environmental exposures, recognition of the unique challenges presented at different life stages for both outcome and exposure measurement, and the importance of ethical issues that must be dealt with in a changing medical and legal environment. It is hoped that these articles will be of value to others who are embarking on studies of children’s environmental health.


The National Children’s Study: a 21-year prospective study of 100,000 American children.

Landrigan PJ, Trasande L, Thorpe LE, Gwynn C, Lioy PJ, D’Alton ME, Lipkind HS, Swanson J, Wadhwa PD, Clark EB, Rauh VA, Perera FP, Susser E.  Center for Children’s Health and the Environment, Department of Community and Preventive Medicine, New York, New York, USA. phil.landrigan@mssm.edu  Pediatrics. 2006 Nov;118(5):2173-86.

Prospective, multiyear epidemiologic studies have proven to be highly effective in discovering preventable risk factors for chronic disease. Investigations such as the Framingham Heart Study have produced blueprints for disease prevention and saved millions of lives and billions of dollars. To discover preventable environmental risk factors for disease in children, the US Congress directed the National Institute of Child Health and Human Development, through the Children’s Health Act of 2000, to conduct the National Children’s Study. The National Children’s Study is hypothesis-driven and will seek information on environmental risks and individual susceptibility factors for asthma, birth defects, dyslexia, attention-deficit/hyperactivity disorder, autism, schizophrenia, and obesity, as well as for adverse birth outcomes. It will be conducted in a nationally representative, prospective cohort of 100,000 US-born children. Children will be followed from conception to 21 years of age. Environmental exposures (chemical, physical, biological, and psychosocial) will be assessed repeatedly during pregnancy and throughout childhood in children’s homes, schools, and communities. Chemical assays will be performed by the Centers for Disease Control and Prevention, and banks of biological and environmental samples will be established for future analyses. Genetic material will be collected on each mother and child and banked to permit study of gene-environment interactions. Recruitment is scheduled to begin in 2007 at 7 Vanguard Sites and will extend to 105 sites across the United States. The National Children’s Study will generate multiple satellite studies that explore methodologic issues, etiologic questions, and potential interventions. It will provide training for the next generation of researchers and practitioners in environmental pediatrics and will link to planned and ongoing prospective birth cohort studies in other nations. Data from the National Children’s Study will guide development of a comprehensive blueprint for disease prevention in children.



Principles and practices of neurodevelopmental assessment in children: lessons learned from the Centers for Children’s Environmental Health and Disease Prevention Research.

Dietrich KN, Eskenazi B, Schantz S, Yolton K, Rauh VA, Johnson CB, Alkon A, Canfield RL, Pessah IN, Berman RF.  University of Cincinnati College of Medicine, Division of Epidemiology and Biostatistics, Department of Environmental Health, and the Cincinnati Children’s Environmental Health Center, Cincinnati, Ohio, USA.  Environ Health Perspect. 2005 Oct;113(10):1437-46.

Principles and practices of pediatric neurotoxicology are reviewed here with the purpose of guiding the design and execution of the planned National Children’s Study. The developing human central nervous system is the target organ most vulnerable to environmental chemicals. An investigation of the effects of environmental exposures on child development is a complex endeavor that requires consideration of numerous critical factors pertinent to a study’s concept, design, and execution. These include the timing of neurodevelopmental assessment, matters of biologic plausibility, site, child and population factors, data quality assurance and control, the selection of appropriate domains and measures of neurobehavior, and data safety and monitoring. Here we summarize instruments for the assessment of the neonate, infant, and child that are being employed in the Centers for Children’s Environmental Health and Disease Prevention Research, sponsored by the National Institute of Environmental Health Sciences and the U.S. Environmental Protection Agency, discuss neural and neurobiologic measures of development, and consider the promises of gene-environment studies. The vulnerability of the human central nervous system to environmental chemicals has been well established, but the contribution these exposures may make to problems such as attention deficit disorder, conduct problems, pervasive developmental disorder, or autism spectrum disorder remain uncertain. Large-scale studies such as the National Children’s Study may provide some important clues. The human neurodevelopmental phenotype will be most clearly represented in models that include environmental chemical exposures, the social milieu, and complex human genetic characteristics that we are just beginning to understand.