Life Stages Research

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The Issue | Science Objectives | Research Highlights | Impact and Outcome

The Issue

Your age can make a difference for risk to pollutants in the environment, either because you may be more highly exposed, or because you may have a greater response to exposures. Research has documented that risk to environmental pollutants can be greater for the very young and adults over 65 years of age. Core or basic research is needed to help us understand how to protect individuals during these more sensitive stages of their lives.

EPA's science will bring about improved understanding of how and why the very young and older adults may be at greater risk to some pollutants. This life stage research also will examine how schools and communities can reduce risks to sensitive populations. With a growing body of knowledge on the exposures and health impacts of pollutants on children and the elderly, risk assessments can be developed to better protect these susceptible groups.

Science Objectives

The goal of life stage research is to provide a fundamental understanding of the many factors that can lead to increased risk to sensitive populations. Research will focus on how exposure to pollutants may be impacted by life stage, determine if there are unique biological responses, and evaluate the developmental time periods (i.e., so called "windows of susceptibility") during which children may be more susceptible to certain environmental toxicants. This research focuses on three general approaches: (1) research on the long-term effects following developmental exposure, (2) development of tools to measure exposure and effects in older populations; and (3) studies on specific exposures and associated effects in children.

Research Goals:

Elucidate early biological indicators of effect, mode of action, and potential biomarkers that vary as a function of life stage
Identify methods and develop models that can be used to assess life stage exposures and susceptibility
Develop efficient study designs (e.g., age groups for exposure assessments) to study effects of and exposure to chemicals as a function of life stage
Identify potential susceptible subpopulations based on life-stage-dependent exposures, activity patterns, and health status that could significantly change current risk assessment practices and policies
Develop integrative exposure-dose-response models for quantitatively characterizing susceptibility to environmental pollutants in susceptible subpopulations and minimizing reliance on default assumptions in assessing risk
Develop and verify information to support an Exposure Factors Handbook for the aging (similar to that already developed for children) that can be used by EPA, States, and local agencies, as well as community associations, for evaluating the potential risks of environmental pollutants
Provide guidance to EPA concerning the appropriate use of safety factors to protect potentially sensitive subpopulations.
Develop both qualitative and quantitative exposure assessment methods that can be applied to longitudinal methods
Develop broadly applicable risk management solutions that will allow schools to carry out practical action plans to improve indoor air quality and protect children's health at a reasonable cost

Research Highlights

EPA-supported children’s centers conduct life stage research
Long-term effects of developmental exposures. Research to date has produced preliminary data indicating that prenatal chemical exposure in rodents, as well as maternal undernutrition, results in elevated blood pressure in young adult offspring. This effect is more prominent in male offspring, although the mechanism underlying this gender difference in sensitivity is unknown. Ongoing research is designed to assess the effects of adverse developmental environments on life long health. Toxic exposures during development may affect health later in life, by increasing the risk of disease.
Measuring exposure and effects in older populations. Information is being collected to identify exposures, activity patterns, confounding stressors, and subpopulations of concern in the older-adult community. This effort will identify gaps in current understanding that are expected to be numerous. Survey, laboratory, and clinical data are being integrated to create predictive models of exposure, activity patterns, metabolism and physiology that can be used to strengthen the assessment of health risks for older adults.
Measuring health effects in children. Research is being conducted to characterize the differential response of the young to the neurobehavioral and neurochemical effects of cholinesterase-inhibiting pesticides (carbamates and organophosphates) and determine the biological mechanisms for these differences.
Measuring exposures in children. A framework and protocols were developed for systematically identifying and addressing the most important sources, routes, and pathways of children's exposure. A set of highly focused research studies was conducted to fill critical data gaps related to children's chemical exposures in their everyday environments. Results of these studies have developed information on product use patterns, environmental concentrations, and the activities that impact exposure. The data from these research studies have been used by EPA's Office of Research and Development (ORD) to develop state-of-the-art aggregate exposure and dose models.
Risk management solutions. ORD research concerning children is focusing on developing guidance for potentially high-risk products and broadly applicable risk management solutions for schools to protect children. Data generated from this study will ensure a comprehensive evaluation of widely used consumer products that affects a large population, including school children.

Impact and Outcomes

Human Health Research Contributions

Characterizing exposures to toxic agents related to the World Trade Center Disaster
Developing an Integrated Pest Management Program for intervention by local health departments and housing authorities
Developing the National Agenda for the Environment and the Aging
Developing protocols for the National Children's Study
Drafting the child-specific Exposure Factors Handbook
Providing supplemental guidance for assessing cancer susceptibility from early life exposure to carcinogens
Writing the framework for assessing risks of environmental exposures to children
Developing guidance for selecting appropriate age groups for assessing childhood exposures
Characterizing aggregate exposures of young children to common contaminants in their everyday surroundings in the Children's Total Exposure to Persistent Pesticides Study
Reports from the National Children's Study
A report entitled A Decade of Children's Environmental Health: Highlights from EPA's Science to Achieve Results Program (40 pp, 1.44 MB, About PDF)focuses on 10 years of research funded or performed by EPA's National Center for Environmental Research's Science to Achieve Results (STAR) grants program.