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Environmental pollutants and aging: Investigating and modeling mechanisms of susceptibility in later life.
Citation:
MACPHAIL, R. C. AND M. J. DEVITO. Environmental pollutants and aging: Investigating and modeling mechanisms of susceptibility in later life. Presented at Gerontological Society of America, San Francisco, CA, November 16 - 20, 2007.
Impact/Purpose:
To support criteria of MYP
Description:
The rapidly expanding population of older adults raises new concerns over their potential vulnerability to environmental pollutants. Decreases in organ-system function and defenses, coupled with reduced metabolic capacity and clearance, are likely mechanisms for enhanced vulnerability. Laboratory research is underway at EPA to evaluate the relative sensitivity of an animal model of aging to environmental pollutants. Evaluations of the brain, heart, liver and kidney are carried out before and after exposure to toxic chemicals. Our goal is to develop a quantitative, biologically-based model of susceptibility, linking toxicant effects at the gene-expression, biochemical, physiological and behavioral level, that can be used to predict the risk of impairment in aging humans. Initial research has focused on the effect of toluene, a contaminant in air and water, in young (4-5 month), middle-age (12-13 month) and old (24-25 month) Brown Norway rats obtained from the National Institute on Aging. Preliminary results indicate toluene’s behavioral and physiological effects are greatest in old rats. Aging-related changes in metabolizing capacity appear minimal. It remains to be determined, however, whether toluene clearance is affected by age. Results of toluene-induced hyperactivity support the generally accepted principle regarding increased individual differences in susceptibility with advancing age. These findings may have a significant impact on the design and analysis of laboratory, clinical and epidemiological research, and how health risks are assessed in the aging population. This is an abstract of a proposed presentation; the information does not necessarily reflect Agency policy.