At a local family practice clinic, several teenagers have presented with mysterious flu-like symptoms. One patient has been hospitalized and is in serious condition. The state health department is investigating the possibility of an illness related to rodent droppings and is interviewing the patients, their families, and their physicians.
* * *
For the third time in a month, a mother has brought her coughing, wheezing two-year-old daughter to the local emergency room. And, for the third time, the child is treated with bronchodilators and sent home with a diagnosis of asthma.
* * *
A reporter from the local newspaper is investigating a cancer cluster in the community. She is interviewing local physicians about the health effects of hazardous waste incineration and about electromagnetic fields.
* * *
The above examples are typical of the complex questions and situations associated with environmental factors increasingly encountered by physicians, who, in the course of their clinical training, may have had little preparation for dealing with them. Unaware of this potential shortcoming and faced with growing concerns about the potential health effects of environmental damage and contamination, people seek help from their physicians because, in general, they trust them and value their advice (McCallum and Covello, 1989). In order to respond appropriately, physicians need to be clinically competent in environmental medicine and dissuaded from the all too common practice of reflexively offering blanket reassurance to patients who feel they have been exposed to, or harmed by, an environmental toxicant.
The environment, including the work environment, is a critical factor for both health and disease. There is clear evidence that the health effects of environmental agents and environmental degradation are serious, whether they are direct, such as the effects of lead exposure on infant and child development (Bellinger et al., 1986), or indirect, such as the effects of climatic changes on vector distribution and ecosystem damage resulting in outbreaks of infectious disease (Epstein and Sharp, 1993; Leaf, 1989; see Box 2).
Box 2. Hantavirus Pulmonary Syndrome
A 19-year-old man presented to an emergency room in New Mexico in May of 1993 with an acute respiratory illness. The man was a marathon runner, previously in excellent health; his fiancée had died two days earlier with a severe respiratory illness. On exam, the patient was febrile, tachycardic, and tachypneic, but the rest of the physical exam was normal. The chest x-ray was clear, and laboratory findings were unremarkable. The patient was sent home on erythromycin and amantadine. Over the next two days the symptoms continued, and the patient developed vomiting and diarrhea. Repeat physical exams showed little change and clear lung fields. The next day the patient developed rapidly progressive shortness of breath and a cough productive of copious yellow sputum. Over several hours the patient developed fulminant respiratory failure and died.
This was the second person struck by the now famous Hantavirus pulmonary syndrome outbreak in the southwestern United States in the summer of 1993. The outbreak of the disease can be traced to unusual environmental conditions in the area. A rainy summer the previous year led to a large increase in the crop of piñon nuts; this in turn led to a rodent population explosion in the area. We now know that various species of rodents throughout the United States carry this strain of Hantavirus, and unrecognized cases among people may have occurred previously. The environmental factors that led to the increase in the reservoir population, and to inevitably closer contact between people and the rodents, resulted in the “emergence” of the disease at that time and place.
What may seem like subtle environmental changes can clearly have a significant impact on disease spread. The penetration of humans deep into tropical rainforests may bring people into contact with previously unknown diseases (HIV may have emerged in this way). Jet travel allows infected humans to spread disease rapidly around the world. Global warming may greatly expand the range of many vector populations, such as the Asian tiger mosquito, which was recently introduced into the United States in a shipment of wet automobile tires, and is now rapidly spreading throughout the southern United States. Finally, the enormous population density in many third-world cities provides a setting ripe for the rapid transmission of many diseases. All of these environmental factors are cause for concern about future outbreaks or epidemics of infectious disease.
Adapted from Duchin et al. (1994).
See also case study 17 in Appendix C.
Although the precise impact of environmental illness and injury is virtually impossible to compute—partly because adequate surveillance mechanisms do not exist and partly because environmentally related disease often goes unrecognized as such—there is enough undisputed evidence of the relationship between environmental exposure and disease to justify moving from concern to action. For example, the Centers for Disease Control and Prevention estimates that 3 million preschool children in the United States have blood
lead levels greater than 10 µg/dl, a level associated with neurotoxic effects (Centers for Disease Control, 1991). The prevalence of asthma, especially among children (Larsen, 1992; National Center for Health Statistics, 1989), and of waterborne diseases from chemical contamination is increasing (U.S. Department of Health and Human Services, 1991). There is growing concern that a substantial fraction of cases of cancer and a variety of adverse reproductive outcomes may be associated with environmental agents (Landrigan, 1993; Paul, 1993). Similarly, there is also growing concern about the possible relationship between pesticides and breast cancer (Wolff et al., 1993). In addition, illness and injury related to occupational exposures and conditions continue to take their toll on the U.S. workforce, with 6.3 million job-related illnesses and injuries reported by the private sector in 1991 alone (U.S. Department of Labor, 1993).
Despite the association between environmental contaminants and adverse health effects, the use, release, and disposal of potentially toxic chemicals into the environment continues. In 1991, U.S. industry reported the release of 3.39 billion pounds of potentially toxic chemicals into the air, water, and soil (U.S. Environmental Protection Agency [EPA], 1993). Also in 1991, more than 31,000 sites had been reported to the EPA as potentially in need of cleanup; 1,189 of these were designated as hazardous waste (Superfund) sites.
In addition to these specific examples of the important relationship between the environment and health, there are other reasons why primary care physicians need to understand the basic concepts of environmental medicine. First, the increased use of right-to-know laws in the context of the workplace, the community, and in the labeling of consumer products means that the public will have more information about chemical threats. The increased availability of information will make it more likely that patients will appear in their physicians’ offices seeking advice about the possible relationship of these chemicals to their current symptoms or their potential for future adverse effects.
Second, recent advances in molecular biology suggest that medical science will soon be able to tease out the role of genetic factors in common diseases. If genetic factors cannot be identified or are found to provide a less than full or satisfactory explanation about why individuals contract a particular disease, the need to focus on environmental factors will grow. These same advances in biology pose every likelihood of providing direct insights into the relationship between environmental factors and common diseases.
Finally, physicians’ skills and knowledge must be adequate not only for treating their patients but also for explaining their actions in public health, legal, and regulatory arenas, if necessary. The magnitude of the production, use, release, and disposal of known and suspected toxic agents gives some urgency to the need for physician participation in these contexts.
Thus, given the widespread distribution of environmental hazards and their potential effect on the health of individuals and populations, one can expect only increasing demand for information, services, and treatments from medical professionals in the future. By taking an active role in educating and preparing their students in environ-
mental medicine today, medical schools can demonstrate leadership in caring for people adversely affected by or concerned about environmental agents.
DEFINITION AND SCOPE OF ENVIRONMENTAL MEDICINE
The potential adverse health effects of environmental factors are generally well recognized by the medical community but not always well understood. In its broadest sense, the environment is at least partially responsible for all diseases except those determined solely by genetics, and includes such factors as housing, nutrition, socioeconomic status, and life-style. For the purposes of this report, however, the Committee on Curriculum Development in Environmental Medicine defines “environment” and “environmental medicine” more narrowly and in conceit with the definitions in the 1988 Institute of Medicine (IOM) report Role of the Primary Care Physician in Occupational and Environmental Medicine. That is, the committee’s use of the term environmental medicine refers to diagnosing and caring for people exposed to chemical and physical hazards in their homes, communities, and workplaces through such media as contaminated soil, water, and air. This definition excludes diseases caused by tobacco use, alcohol, diet, or other life-style factors as well as conditions that are a direct consequence of genetics, violence, and iatrogenically caused illness or injury. As stated in the 1988 report, this definition is not meant to diminish the importance of these factors in disease, but to reflect a concern and strong belief that non-life-style environmental factors are equally deserving of study and attention; in this view, when taking a history or formulating a diagnosis, physicians should consider non-life-style environmental factors, such as workplace, home, and community exposures, as well as the “traditional” environmental factors such as alcohol and nicotine.
Occupational exposures are some of the most important environmental exposures, and many of the concepts and principles of occupational medicine are directly relevant and applicable to environmental medicine. Like occupational medicine, which is limited to the workplace environment, environmental medicine is prevention oriented. In essentially all cases, environmentally induced illness and injury are preventable, largely through nonmedical risk management interventions, such as engineering design, product substitution, and education. Thus, many of the most effective prevention activities of environmental medicine occur outside the traditional clinical paradigm. However, many of the interventions flow directly from an individual physician-patient encounter that identifies a health problem or risk attributable to specific environmental factors or conditions. The clinical encounter provides a unique opportunity for the clinician to practice prevention-oriented primary care. Moreover, a single diagnosed case of environmental or occupational illness often serves as a sentinel, alerting the public health community that prevention has failed, that other members of the population may be at risk, and that intervention is needed (Rutstein et al., 1983).
ROLE OF THE PHYSICIAN
For many years, physicians and other health care providers have been largely uninvolved in environmental issues related to human health. Certainly, their undergraduate and graduate medical education did little to encourage or prepare them for such involvement. Indeed, the paucity of their training in this area has been well documented (Institute of Medicine, 1988; Levy, 1985). Surveys have shown, for example, that in 1985 only 50 percent of U.S. medical schools included occupational and environmental health in their curricula, with an average of only four hours being taught over four years (Levy, 1985). By 1992, improvement was only modest, with 66 percent of schools requiring about six hours of study in occupational and environmental health (Burstein and Levy, 1994). A survey of 89 departments of internal medicine at U.S. medical schools found that only 22 percent offered occupational medicine experiences, almost all of which were elective (Cullen and Rosenstock, 1988). Resident training in the broader area of environmental medicine has been even less common.
Moreover, a review of the curriculum catalog from the Association of American Medical Colleges (1993) indicates that courses in environmental medicine are rare and, when offered, are usually elective in nature, competing with many popular alternatives.
Medical education’s focus on the individual patient with disease has not encouraged faculty and students to step beyond the medical model and consider the health of the population—be it the physician’s practice population, a worker population, a neighborhood or community population, or the population of a state, region, or nation. Blame might also be placed on the many well-known deficiencies of the medical education system—a system that has compartmentalized teaching and learning into rigid disciplines, focused on information transfer instead of information management and problem solving, and rewarded research over teaching (Association of American Medical Colleges, 1983; 1992a).
There are other explanations for physician noninvolvement, however. Practical constraints are enormous; physicians often just do not have the time to get involved in their patients’ environmental or occupational health problems, many of which are complex and time consuming. The technical aspects of such environmental problems as air pollution, occupational disease, and toxic emissions can be daunting. Moreover, reimbursement for time spent on environmental questions is often lacking, and administrative burdens such as those imposed by worker’s compensation cases may be formidable (Institute of Medicine, 1988). Indeed, the realities of clinical practice reinforce the practitioner’s need to focus on the individual patient with disease. Furthermore, in the area of environmental (and occupational) health, the possibility of interaction with the legal system looms large in the minds of some physicians; however remote, this possibility can discourage some physicians from pursuing an environmentally
There may also be philosophical, political, social, and cultural explanations for lack of physician involvement. For example, it has been suggested that physicians are sometimes uncomfortable with the priorities of environmental activists (Guidotti, 1991). With growing public awareness and concern about the health effects associated with environmental agents, however, physicians and other health care providers can no longer avoid involvement in environmental medicine.
A Continuum of Roles
In 1988, the IOM examined the role of primary care physicians in occupational and environmental medicine and, as a result, called for enhanced physician training and education in this area. Noting that primary care physicians are often the health professionals of first contact for patients with environmentally related illnesses, the IOM suggested that as a minimum, all primary care physicians should be able to identify such illnesses and refer patients appropriately for follow-up (Institute of Medicine, 1988). Two subsequent IOM reports on occupational and environmental medicine addressed physicians’ needs for medical information (Institute of Medicine, 1990) and the physician shortage in occupational and environmental medicine (Institute of Medicine, 1991).
Following up on the IOM’s 1988–1991 series of reports, this committee has described a continuum of roles that physicians can assume in the area of environmental medicine (see Box 3).
At one end of the continuum is the role of the environmentally competent clinician. At the very minimum, this role includes the ability to identify possible environmentally related conditions to make the appropriate referrals for evaluation and follow-up care. To conduct even this limited activity, physicians will need to obtain certain knowledge and develop certain skills that are not routinely provided in U.S. medical education. With this and additional training, clinical competence can be expanded to include the ability to appropriately diagnose, treat, and manage patients with environmentally related disease as well as the ability to conduct basic and clinical research and to educate and counsel patients about environmental risks. The latter function will become increasingly important as patients seek advice from their physicians about the safety of drinking water, pesticide-contaminated food, “sick” buildings, “toxic” carpets, hazardous working conditions, and suspected clusters of cancer, miscarriage, and other diseases.
Moving beyond this clinician-educator role toward the other end of the continuum, physicians can expand into areas of increasing activism in relation to individual and pub-
Box 3. A Continuum of Roles
A continuum of roles illustrates several levels and types of activity for physicians in the area of environmental medicine. Physicians can:
lic health and the environment. Indeed, there have been calls for “environmentally literate” physicians who will serve as spokespersons and leaders in environmental issues (Cortese and Armoudlian, 1991; Guidotti, 1991; Leaning, 1990; McCally and Cassel, 1990).
The extent of an individual physician’s activity in environmental medicine is, in large measure, a matter of personal preference. However, there is little doubt that basic clinical competence in environmental medicine is essential for all physicians. As individual and community concerns about the environment grow, physicians will encounter inquisitive, confused, at-risk, and diseased patients in their offices—patients with questions, concerns, complaints, signs, and symptoms. Medical schools need to respond to society’s growing environmental concerns by developing educational programs that teach clinicians how to meet these needs. An important long-term goal in this regard would be the establishment of a network of specialists in the field to whom referrals can be made. The Association of Occupational and Environmental Clinics (see Appendix D) provides a good example of a national network of clinical facilities dedicated to research and education as well as to the prevention and treatment of occupational and environmental diseases.
ORIGIN AND ORGANIZATION OF THE REPORT
In 1992, at the request of the Agency for Toxic Substances and Disease Registry (ATSDR) of the U.S. Public Health Service, and with subsequent support from the Environmental Protection Agency (EPA) and the National Institute for Occupational Safety and Health (NIOSH), IOM convened the present committee to continue and build upon previous work by the IOM in defining and fostering environmental medicine. The committee was given six specific tasks:
define the scope of activities in environmental medicine,
identify essential competencies in environmental medicine,
develop learning objectives in environmental medicine,
recommend methods for faculty development,
identify resources for faculty training in environmental medicine, and
recommend methods for integrating environmental medicine into medical education and evaluating its effectiveness.
The committee convened a public workshop in May 1993 to help begin the process, and issued an interim report in the fall of 1993 that recommended establishing six competency-based learning objectives, on which the present report builds.
Although the committee’s charge was to focus on undergraduate medical education, it was difficult for the committee to conceive of accomplishing its objectives solely within those confines. The context of the continuum of undergraduate and graduate medical education seemed more appropriate because environmental medicine permeates the entire spectrum of medical practice and should similarly reach throughout the continuum of medical training. Some of the discussion in this report therefore refers to residency training and continuing medical education.
The chapters and appendixes that follow reflect the committee’s further pursuit of its six tasks. The report articulates a general program of implementation strategies and provides immediate practical advice to individual educators, students, and practitioners who either are interested in integrating more environmental medicine content into medical education or need resource information to help them address clinical situations.
Chapter 2 begins by laying the foundation for an environmental medicine curriculum centered on six competency-based learning objectives. Chapter 3 then uses these objectives as a framework for identifying likely access points in the curriculum for integrating environmental medicine into today’s medical studies. Chapter 4 addresses both the barriers to implementing such a curriculum and the opportunities for reducing these barriers. Chapter 5 presents concluding remarks that summarize some of the events that led to this report and the committee’s optimism with respect to the ease with which medical education can incorporate an enhancement of the training of environmental medicine. Recommendations for integrating an enhanced program of environmental medicine throughout our system of medical education and practice appear at the ends of the individual chapters (i.e., Chapters 2–4).
To enhance the report’s practical value, four appendixes are included that provide detailed information on available educational resources and teaching aids. They can be used to facilitate the integration of environmental medicine into both education and practice. Appendix A contains a case study developed by the ATSDR on “Taking an Exposure History”; it is a good example of a tool for teaching or learning how to elicit a good environmental history. Appendix B, “Medical School Courses and Clerkships: Access Points for Integrating Environmental Medicine,” illustrates the relevance of and
opportunities for integrating environmental medicine into common medical school courses and clerkships/clinical rotations. It also identifies case studies from Appendix C that could be used in these courses or contexts. Appendix C, “Case Studies in Environmental Medicine,” contains 55 case studies that should be useful in teaching and learning. This appendix has four indexes to help the reader determine the most relevant cases for a particular course, clerkship, or other purpose. The case studies are indexed by (1) chemical agents and conditions; (2) common medical school courses and clerkships/clinical rotations; (3) sentinel pathophysiological conditions; and (4) clinical signs, symptoms, and presenting complaints. Appendix D, “Resources: Agencies, Organizations, Services, References, and Tables of Environmental Health Hazards,” identifies various sources of information, including governmental agencies (federal and state), environmental associations and organizations, regional and international information services, computerized information services, resources by selected topic (e.g., air pollution, clean water, and radon), general reference books and journals, a medical school listing of environmental medicine activities, and several tables of toxic chemicals, health effects, and occupational exposures. It is our hope that these materials and resources will facilitate the integration and enhancement of environmental medicine in medical education.