The Roundtable on Environmental Health Sciences, Research, and Medicine is a mechanism that the Institute of Medicine (IOM) uses to convene representatives from academia, government, and industry. By bringing together people with diverse views, the Roundtable provides a forum in which environmental health issues can be discussed by looking broadly at the built, the social, and the natural environments, all of which come together in complex interactions. Through their discussions, the members of the Roundtable look beyond narrowly focused topics and consider the larger environmental factors that influence public health.
At a workshop sponsored by the Institute of Medicine’s Roundtable on Environmental Health Sciences, Research, and Medicine in June 2000, Rebuilding the Unity of Health and the Environment: A New Vision of Environmental Health for the 21st Century, many participants expressed the view that for a long time the world of environment, environmental regulation, environmental control, and engineering had moved in one direction while the world of health had moved in another. From this realization arose the concept of holding a series of workshops on rebuilding the unity of health and the environment in various regions of the United States. The purpose was to bring representatives from the two worlds together to address issues of health and environment specific to each region.
The Roundtable has already hosted regional workshops in Atlanta, Pittsburgh, and Houston, said Roundtable member James Merchant. At the latest workshop of the Roundtable on Environmental Health Sciences, Research, and
Medicine (held at the University of Iowa, Iowa City, on November 29 and 30, 2004), the Roundtable addressed rural environmental health issues in an interactive way, with those attending the discussions participating in a free exchange of views on how to rebuild the unity of health and the environment in rural America. The remainder of this chapter and the chapters that follow describe and summarize the participants’ presentations to the Roundtable members and the discussions that the members had with the presenters and participants at the workshop.
WHAT IS ENVIRONMENTAL HEALTH?
According to the World Health Organization (WHO), environmental health is defined as “those aspects of human health, including quality of life, that are determined by interactions with physical, chemical, biological and social factors in the environment” (WHO, 1986). Environmental health thus focuses on the quality of life and not simply on the absence of disease, and all the factors that contribute to environmental health, including the environment, are assessed when the environmental health of a population or region is evaluated.
Many researchers and investigators have created their own image of the interactions among health, behavior, biology, and genetic factors and the outcome, whether it is disease or health and function. Overlying these interactions are social, natural, and built environmental factors, remarked Roundtable member Donald Mattison. In developmental health, for example, researchers are beginning to realize that many of the events that lead to health disorders occur in utero or early in childhood, so it is important to understand the factors that ultimately lead to these disorders in adults. Most aspects of health are a direct result of the environments in which humans grow up, live, work, and play. Therefore, the solutions to public health problems cannot be left solely to the health care system; they require interactions among a broad group of individuals with expertise in a variety of areas.
Risk reduction and health promotion influence the development of health. Thus, consider a graph with health development—e.g., pulmonary function, cognitive function, or executive function—along the vertical axis and time along the horizontal axis. Mattison noted that because of a range of exposures or other factors, the trajectory that an individual might have followed across some period of time might be lower than what the optimum trajectory for health development for that individual could have been. However, if health promotion and risk reduction strategies had been put into place, the same individual might have been able to move through various stages of life and reach or approach the optimum trajectory. From what is known about the early origin of diseases in adults, it can be concluded that it is most important to act early to reduce risks and put in place strategies that promote health.
Obesity is a good example, noted Mattison. A lot of the focus on obesity has
been straightforward; it is known that the balance between physical activity and caloric intake affects body size. Inactivity plays a major role in child obesity as well. Today, an average child in the United States spends more time watching television than attending school in any given year (Finn, 1980). However, data from a range of population studies demonstrate that intrauterine factors can predispose individuals to increased body size in adulthood. Moreover, policy decisions made in the late 1960s and 1970s that changed the way in which foods are prepared and sold commercially may also have played a role in some of these outcomes, noted Mattison. Therefore, while physical inactivity plays a role, a broad perspective needs to be taken to understand what has led to this change in body size.
From what is know about the early origin of diseases in adults, it can be concluded that it is most important to act early to reduce risks and put in place strategies that promote health.
The proportion of individuals with a body mass index (BMI) higher than 30 kilograms per square meter (kg/m2) is rapidly increasing. Research on obesity in 1990 found that 10 percent to 14 percent of the population had a BMI higher than 30 kg/m2 whereas in 2000 in some states more than 20 percent of individuals had BMIs at or above 30 kg/m2. Currently, in some states the proportion of the population with a BMI of 30 kg/m2 or more has surpassed 25 percent (Must et al., 1999). The impact on children is similar: the proportions of overweight children in 1963, 1965, and 1999 were 11, 12, and 19 percent, respectively. According to a recent Institute of Medicine (IOM) report, the cost of the obesity problem in adults is between $98 billion and $129 billion annually, said Mattison (IOM, 2004).
The definition of environmental health has evolved with research; therefore, the goals of environmental health should be to establish and maintain a healthy environment, to promote an environment that improves well-being both in function and in structure, and to allow the environment to be sustainable.
Other factors in addition to developmental health could have contributed to the child obesity problem in the United States. The built environment affects the way in which children exercise. For example, in suburbia, fences between houses make the otherwise sculptured environment inhospitable. The result of this inhospitable environment is that children are being driven to their friends’ homes rather than biking or walking themselves. According to the Nationwide Personal Transportation Survey issued by the U.S. Department of Transportation’s (DOT’s) Federal Highway Administration (FHWA), the average number of daily vehicle trips per household grew 12 percent between 1990
and 1995. Also, the average number of annual person trips per household by the use of mass transit systems dropped from 2.6 percent in the 1970s to about 1.8 percent in 1995. Since then it has stayed relatively constant that the main mode of transportation is by car (DOT, FHWA, 1999).
Although the incidence of Type II diabetes among adults over the age of 40 years is increasing at an alarming rate, the gravest concern at the National Institute of Child Health and Human Development is the trend of an increasing incidence of Type II diabetes among children. This increase accounts for the rapidly expanding research and development efforts by the pharmaceutical industry into potential tools for the management of Type II diabetes. Although evidence clearly indicates that fat cells play a role in moderating the insulin response and insulin sensitivity, evidence also indicates that some of the factors that occur during the course of pregnancy play a role as well, noted Mattison.
In 2002, as a response to public health data indicating that prematurity is the one area in maternal and child health that has worsened, the Roundtable conducted a workshop on the role of environmental factors in premature birth (IOM, 2003). Although the incidence of prematurity has increased over the years, the incidences of all other health conditions of concern in maternal and child health, such as maternal mortality, infant mortality, and birth defects, have improved. The problem with prematurity is not only that a child is born before he or she has reached full term and needs special care, but also that the complications or impacts of prematurity, personal as well as familial and societal, are lifelong. The Roundtable activities revealed interesting, emergent themes around prematurity that suggest that gene–environment interactions and social factors affect prematurity.
The definition of environmental health has evolved with research; therefore, the goals of environmental health should be to establish and maintain a healthy environment, to promote an environment that improves well-being both in function and in structure, and to allow the environment to be sustainable, concluded Mattison.