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AGING AND THE ENVIRONMENT
Impact/Purpose:
The overall goal of this work is to develop information to assess potential environmental health risks and susceptibility in the aging population. Initial work will be directed toward developing information that can be used to identify and characterize what is known about exposure, dose, and biological effects for key life stages in the aging population and to identify key data gaps to be addressed through further research. Work under this task may also incorporate or investigate elements of the cumulative exposure research plan for multiple stressors in potentially susceptible sub-populations and communities. Specific research objectives have been identified to address four discrete elements of the environmental paradigm for an aging population.
1) Identify key chemical and biological stressors in the aging population, compile extant information on exposures to these agents and the extent to which they may be different in aging and other populations, and identify key gaps in our knowledge of exposure to important stressors.
2) Identify the key life stages in the aging population with regard to exposures and susceptibilities to chemical and biological stressors. Compile activity pattern information for aging Americans in key life stages, including information on physical activity, time and location information, dietary intakes, and pharmaceutical use that may impact exposures and/or susceptibility. Identify key gaps in our knowledge of activities in subpopulations of the aging by life stages.
3) Identify important aging-related changes in pharmacokinetics and pharmacodynamics that may increase susceptibility to adverse effects from envrionmental stressors, develop pharmacokinetic models appropriate for susceptible subpopulations of the aging, and identify key gaps in knowledge of physiological processes in the aging.
4) Use the information developed for exposure, activity, and pharmacokinetics to extend existing source to dose models to aging populations and susceptible subpopulations at different life stages for use in risk assessment and identify key data gaps that must be filled to improve such models.
Description:
In October 2002, the US EPA announced an Aging Initiative to develop a comprehensive and coordinated approach to addressing the environmental health concerns and risks that may confront the nation's rapidly expanding population of older adults. This initiative was motivated by the realization that, with aging, our organ systems may become more vulnerable to environmental hazards (e.g., reduced reserve capacity) accompanied by a reduced capacity to detoxify and eliminate toxicants. Health effects resulting from a lifetime of toxicant exposures may also become manifest with age. Moreover, patterns of resource utilization by this growing population may generate novel ecological pressures. EPA's development of a research framework to address these issues has benefitted from input derived from a December 2002 National Academy of Sciences (NAS) Workshop and six public meetings held throughout the United States in spring 2003. To address health issues, EPA has proposed to apply an environmental public health paradigm to better understand the relationships between external pollution sources, human exposures, internal dose, early biological effect, and adverse health effects for this sub-population. In addition to considering the health effects of exposure on healthy older adults, EPA will use information about aging-related changes in exposure, pharmacokinetic, and pharmacodynamic factors to identify particularly susceptible or vulnerable sub-groups within this diverse population. Using a life-stage approach for human risk characterization based on differences in exposures and susceptibility, it will be important to identify the important sub-populations in the aging population with regard to environmental hazards. Data are needed regarding 1) behavior/activity patterns and exposure to chemical and biological pollutants for older adults; 2) changes in absorption, distribution, metabolism, and excretion; and 3) alterations in reserve capacity that alter the body's ability to compensate for the effects of environmental exposures. This task describes work that is planned to address those data gaps as part of a collaborative ORD-wide research framework invloving multiple labs and centers.