Meet Me Halfway

The Environmental Protection Agency wants to merge research in two areas that don't usually mix: aging and the environment.

Plug the word "gerontotoxicology" into Google, and the results hardly give the impression of a burgeoning scientific field. The search yields two hits, both of them to a 1987 report entitled Aging in Today's Environment, published by the National Academy of Sciences (NAS) and supported by the Environmental Protection Agency (EPA) and the National Institute of Environmental Health Sciences. The NAS report called for a collaborative research effort on the part of gerontologists and toxicologists to examine the effects of environmental factors on the health of elderly Americans. The term didn't catch on. Neither did the research agenda--or so it seemed.

But Aging in Today's Environment might have been ahead of its time. Nearly 2 decades later, the concept of combining research on aging and toxicology appears to be on the verge of a vibrant second life. Last October, EPA unveiled an "Aging Initiative," its first attempt to address environmental hazards that can damage the health and well-being of the elderly. In December, EPA Administrator Christine Todd Whitman spoke to an NAS workshop convened to discuss the "Differential Susceptibility of Older Persons to Environmental Hazards," a belated follow-up to the 1987 NAS report. In March, EPA also launched an Aging Initiative Web site, a clearinghouse for information on aging and the environment.

EPA's initiative on aging is still in its infancy: The president's 2004 budget requests only $1 million for research, but it could grow. Following a series of sessions to solicit public comment later this year, EPA officials plan to unveil a "National Agenda on the Environment and the Aging." The program will target gaps in existing research and could set in motion new environmental regulations tailored to protect senior citizens, who are uniquely vulnerable to toxic insults. In addition, EPA administrators hope to study how the geographic distribution and lifestyle choices of seniors might alter the environment. For example, perhaps an inordinate number of golf courses are cropping up in water-starved states such as Utah because seniors are retiring there.

The current initiative is modeled on EPA's previous push to target environmental dangers that pose unique risks to children, which dates back to 1995. It's not surprising that children came first, because their entire lives still lie ahead of them. "If somebody were to come to me with a dollar and say, 'You can spend this on somebody who's 7 years old or somebody who's 70 years old,' there's no doubt I'd spend it on the 7-year-old," says toxicologist Kirby C. Donnelly, head of the Environmental and Occupational Health Department of Texas A&M University's School of Rural Public Health. In the past, many toxicologists have tended to adopt this line of reasoning. But now that EPA is officially turning its attention to the elderly, researchers will presumably follow suit.

And they have a lot to study. According to Aging in Today's Environment, environmental factors influence the process of human aging in three ways. First, the environment can alter the progression of aging-related conditions; for example, sunlight speeds the rate of skin aging. Second, early exposure to environmental hazards, or exposure over a lifetime, can provoke severe health problems that become apparent later.

Finally, for a range of physiological and medical reasons, including their frequent use of prescription drugs, older Americans might be more sensitive to environmental hazards than the general population is. Such enhanced susceptibility occurs with exposure to particulate air pollution, for example, which can aggravate preexisting respiratory conditions such as bronchitis and emphysema. "This type of air pollution appears to strike hardest at the two ends of the age spectrum, the asthmatic children and the older people who already have compromised lung function," says Gina Solomon, a medical doctor and an environmental scientist with the Natural Resources Defense Council.

The same is probably true for other environmental hazards. EPA Administrator Whitman has already named waterborne microorganisms such as Escherichia coli and Cryptosporidium, indoor air pollutants such as radon and carbon monoxide, and other toxicants as likely targets of EPA's new initiative. But scattered studies aside, gerontotoxicological science has not yet probed other pollutants as vigorously as it has explored the effects of particulate matter.

One clear driving force behind the new initiative is demographics. As EPA notes, by the year 2030, "the U.S. population over 65 years of age is expected to double." And in 2011, when the baby boom generation starts turning 65, health care costs--including expenditures on nursing homes and the federal Medicare system--will dramatically increase. If EPA's initiative can reduce environmental stresses on the elderly population, the economic benefits could be considerable. "Politicians undoubtedly realize that the graying of America is going to be a time bomb," explains Edward Masoro, a physiologist at the University of Texas Health Science Center in San Antonio. "That's probably why the EPA is now interested."

The policy recommendations that might ultimately arise from EPA's initiative are still a matter of speculation. Some might clash with the Bush Administration's deregulatory environmental policies. For example, addressing the special risk to the elderly posed by particulate air pollution might require more stringent emission requirements for power plants. But Bush's Clear Skies Initiative would move regulations in the opposite direction.

For Robert Vestal, a toxicologist at the University of Washington, Seattle, who helped prepare the 1987 report, EPA's latest move inspires guarded optimism. On one hand, says Vestal, "it's fine to have an agenda. But if there's no money for it, it's just an agenda"--in other words, a political ploy to garner seniors' votes. Yet Vestal says he's glad that older adults will finally be grouped alongside children on EPA's list of populations that are especially susceptible to environmental hazards. "In a sense, there's finally a follow-up to the 1987 effort," he says. And to monitor the program's success, perhaps all we need to do is periodically type "gerontotoxicology" into Google and count the number of hits.

Chris Mooney is now a gerontotoxico-journalist living in Washington, D.C.