chapter  23
58 Pages

Aging: Characteristics, Exposure Factors, Epigenetics, and Assessment of Health Risks of Older Adults

TrendA recent cover of National Geographic magazine drew national attention with the headline “This baby will live to be 120 New science could lead to very long lives” [1]. Increasing lifespans have two important consequences for health: more people will survive to an age when chronic health conditions impair the quality of life (and increase the cost of health care); and, the elderly will constitute a larger percentage of the total population, further increasing demands on the health care system. In 2011, an estimated 41.4 million persons were aged 65 and older in the United States, representing 13% of the population [2].

By 2030, due to the aging of the baby boomers, the population 65 and older is expected to reach 72 million. It is also important to note that the fastest growing cohort is that of persons 85 years of age and older [3]. Elders will continue to increase in numbers through 2050 when they will are expected to represent 20% of the population. To put this in context, a century ago life expectancy was only about 46 years, roughly 30 years shorter than life expectancy today. Average life expectancy for men and women in 2010 was 76 and 81, respectively. This means that people who survive to age 65 are expected to live another 18.5 years, or roughly four years longer than people aged 65 in 1960 [3]. On the other hand public health experts predict that the trend towards longer lifespans may not continue beyond the current gen-eration. According to Robert Butler the United States has recently fallen from 11th to 42nd in world rankings of life expectancy. He noted that despite advances in medicine and public health, life ex-pectancy might decline in the future due to increasing rates of obes-ity and diabetes, continuing health impacts of smoking and alcohol abuse, and the challenge of poor health care coverage [4]. An important concern in today’s society, with its increased urbanization and dependence on energy and manmade products is the health impacts of exposures to the wide range of industrial chemicals used by modern societies and the extent to which they may decrease resilience and increase the incidence and severity of chronic diseases. With respect to an aging population, it is imperative for us to understand how aging results in unique susceptibilities and vulnerabilities to environmental contaminants and whether aging groups are disproportionately impacted compared with the rest of the adult population. Only with this understanding can risk assessment decisions that are protective of all life stages be implemented with confidence. Do we need to incorporate new information about aging into our approaches for setting environmental standards? 23.3 Why Are Older Adults a Susceptible