In contemporary society, the development of a basic understanding of the environment and health begins early in childhood, and tomorrow’s students will likely enter medical school more sensitive to environmental concerns and, perhaps, with a basic fund of knowledge about the environment and its relation to human health. Our challenge is to ensure that our current and future medical students develop the knowledge, skills, and attitudes needed to deal effectively with environmental health issues in clinical care and in the public health context. Doing this within an undergraduate medical curriculum that has been described as rigid, ossified, stagnant, and unresponsive to societal changes and needs (Abrahamson, 1978; Marston and Jones, 1992; Pew Health Professions Commission, 1991) and reinforcing and expanding this knowledge and skill in the residency years is a formidable challenge.
COMPONENTS OF A CURRICULUM
Although efforts at curriculum reform have failed in the past, medical education may be embarking upon a new era. There are renewed calls for change; those calls and the current evolutionary changes that are occurring in the health care system could be important driving forces for curricular change. Such change could include the introduction and integration of environmental health into the curriculum.
Defining the content of a curriculum in environmental medicine is far easier than ensuring its implementation and integration into existing medical education programs. The latter requires effective leadership and faculty resources, commitment, and skills in addition to an educational climate and format open to experimentation, adaptation, and change.
Developing a curriculum in environmental medicine also requires thoughtful specification—in concrete and, preferably, behavioral terms—of what graduating medical students should know, be able to do, and be sensitive to in the area of environmental health. These “competencies” should also reflect related societal and patient needs. In emphasizing competencies, the committee is expressing its belief that specifying what should be taught is not as useful as describing what students should know and be able to do at the completion of training.
Past recommendations for creating or enhancing a medical school curriculum in environmental health often focused on occupational health. Although many of the underlying principles and concepts of environmental and occupational health are the same, there are also significant differences, some of which may require additional or different learning objectives. Such differences include the absolute level of risk, sources and routes of exposure, possibilities for intervention and environmental manipulation, and a number of administrative, legal, and political issues (Cullen and Figueroa, 1990). Another major difference between environmental and occupational health is the broader range of populations at risk in the former. The expanded focus of environmental health provides the opportunity to involve more clinical specialties in the teaching of environmental health, such as pediatrics, obstetrics/gynecology, and geriatrics.
Current discussions about a curriculum in environmental medicine reveal considerable agreement about certain fundamental components. In its 1988 report, IOM suggested (pp. 47–48) that didactic and clinical training in occupational and environmental medicine provide:
solid grounding in epidemiology and toxicology;
an understanding of the concept of risk and its application to groups and individuals;
a method of obtaining an occupational and environmental health screening history;
concepts of dose response and other factors that contribute to exposure and host response;
knowledge and skill in finding and using information about environmental and occupational diseases; and
sensitivity to special medical, ethical, legal, and economic factors in caring for patients with environmental and occupational diseases.
Other groups have echoed these suggestions and have added several others, such as a focus on risk assessment and risk communication in medical education (American College
of Physicians, 1990) and new methods for improving students’ skills in taking occupational and environmental histories (Kipen and Craner, 1992).
But in addition to the points of overlap and agreement among interested groups, there are other concerns and proposals that require examination. For example, because solutions to individual and community environmental health problems are often preventive and political in nature, students need to learn about the broader array of interventions available in environmental health; an overreliance on the medical model and its clinical interventions may be ineffective or applied too late in the disease process. In simple concrete terms, early lead abatement in the home is preferable to chelation later. Students need to learn how to tap resources in the community to assist with intervention. These resources include public health departments and other government agencies, voluntary organizations, community and consumer groups, and an array of environmental health professionals (see Appendix D).
Similarly, discussions of the concept of risk should go well beyond its epidemiologic definition and its application in risk assessment. Students also need a basic understanding of the elements of risk perception, and they must begin to develop an ability to effectively communicate the concept of risk to patients, especially in the clinical setting.
Another important aspect of the discussion that merits attention concerns the fact that environmental medicine is a field in which information is often missing (e.g., about exposure, dose, risk, and health effects) and in which the economic and political stakes of public action or inaction are often high. Thus, the ability to make decisions in the face of considerable uncertainty is very important. Physicians must be prepared to counsel their patients and communities about environmental health hazards even though little may be known about their long-term health effects. They also need to appreciate how values (their own and those of others) can influence the questions asked, the problems studied, the recommendations made, and the actions taken.
A review of both the points of clear agreement about the components of a curriculum for environmental medicine and the more complex questions of its behavioral, social, and political aspects suggests the following conclusion: any level of physician involvement in environmental medicine, no matter how simple, must rest upon a basic level of competence, which, if realistically defined, should be addressed by all undergraduate and graduate medical education programs. Helping students achieve this basic level of competence should be the primary goal of the curriculum. A realistic curriculum in environmental medicine will (1) identify a small set of competencies, (2) fit comfortably within existing curricular structures, (3) be reinforceable by attending faculty and residents during clinical rotations, and (4) focus on the area that is unique to the physician’s role in environmental health—that is, preserving human health. However, the fundamental breadth and potential ramifications of environmental health issues beyond the realm of clinical medicine require enough flexibility in the curriculum to accommodate students who may wish to take broader, more active roles in environmental medicine and research. To prepare physicians to achieve these goals and fill these roles, this
committee has defined six competency-based objectives that are considered reasonable, achievable, reinforceable, and relevant to the physician’s role in environmental medicine. These objectives, slightly modified from the committee’s interim report (Institute of Medicine, 1993a), provide the framework for developing an implementation strategy described in Chapter 3.
COMPETENCY-BASED LEARNING OBJECTIVES
The integral relationship between the environment and health creates a need for physicians to participate actively in both clinical and community environmental health issues. As expressed earlier, there are things graduating medical students should know, be able to do, and be sensitive to in the area of environmental health. To help physicians acquire and heighten these “competencies,” principles and concepts of environmental medicine must be taught and continually reinforced throughout medical education.
The committee is concerned about the current handling of public health and epidemiology courses in the medical curriculum, both in terms of when they are taught and the lack of emphasis placed on them. These topics are generally taught during the first two years of medical school, along with a plethora of basic science courses that often seem devoid of clinical relevance. Moreover, basic science, epidemiology, and public health are seldom explicitly revisited in the clinical years and in the three-plus years of residency training that follow.
It has already been observed that evolutionary changes in the health care system and pressures to reform medical education may create new opportunities to enhance the teaching of environmental medicine in medical schools. Physicians with expertise and interest in occupational, environmental, and preventive medicine should take the lead in developing creative teaching strategies and in serving as environmentally conscious and active role models for students and residents.
Guided by its belief that specifying what should be taught is not as useful as describing what students should know and be able to do at the end of their undergraduate training, the committee recommends that all graduating medical students have the knowledge and skills described in the following six competency-based learning objectives:
Competency 1. Graduating medical students should understand the influence of the environment and environmental agents on human health based on knowledge of relevant epidemiologic, toxicologic, and exposure factors.
Rationale. There is a clear relationship between the environment and human health. Healthy environments, including workplaces, promote good health, and contaminated or unhealthy environments promote disease. Many types of environmental agents cause, or
put people at risk for, acute and chronic health effects. Although physicians are often well educated in the clinical significance of infectious agents and vector-borne diseases, they often have limited understanding of diseases caused by chemical or physical agents in the environment. A working knowledge of toxicology, epidemiology, and exposure analysis should be an important element in the training of medical students and residents (see Box 4).
Box 4. Methemoglobinemia from Nitrate Exposure
A two-month-old infant was brought by her mother to a small clinic in a rural farming area. The child had a poor appetite for the past two weeks and had persistent loose stools. The mother noted an increasing bluish discoloration around the child’s lips. Over the past few days the infant was crying and fretful, was vomiting and having frank diarrhea. On history, the child was bottle-fed, with formula diluted with tap water. The water source was a well. No other family members were ill.
On exam the child was afebrile, but notably tachypneic, tachycardiac, cyanotic, and drowsy. The child had a new grade II/VI systolic murmur, but the lungs were clear and the rest of the exam was fairly unremarkable. There was no improvement despite administration of 100% oxygen and fluids. The child began to have seizures, cardiac monitoring showed ventricular ectopia, and there was evidence of renal shutdown.
Nitrates avidly oxidize the ferrous iron (Fe++) in deoxyhemoglobin to the ferric (Fe3+) state. This transformation produces methemoglobin, which cannot reversibly bind or transport oxygen. Fetal hemoglobin is more susceptible to oxidation than adult hemoglobin. The resulting clinical picture is one of hypoxia, with CNS depression leading to coma, circulatory failure, and cyanosis.
Nitrates and nitrites are common contaminants of water supplies in farming areas due to runoff of fertilizers in ground water. Contamination of water supplies from animal wastes or from sewer systems also leads to these nitrogen products in water. Preserved meats, and certain medications, particularly topical silver nitrate, which is commonly used for burn therapy, can also lead to methemoglobinemia in infants.
Adapted from Agency for Toxic Substances and Disease Registry, 1991.
See also case study 26 in Appendix C.
Competency 2. Graduating medical students should be able to recognize the signs, symptoms, diseases, and sources of exposure relating to common environmental agents and conditions.
Rationale. Several environmental agents are common causes of disease and disability, and others are increasingly associated with acute and chronic health problems.
An understanding of a few common disease-exposure relationships will provide a broad foundation for an improved general understanding of how environmental agents can affect a variety of organ systems, cause different types of health effects, and be amenable to prevention and control. Examples of important common environmental agents and conditions include lead, organophosphate pesticides, solvents, carbon monoxide, ozone, methylmercury, noise, and asbestos. The choice of specific agents for attention in the curriculum will depend on the medical school, faculty experience and interest, and local environmental and occupational problems.
Competency 3. Graduating medical students should be able to elicit an appropriately detailed environmental exposure history, including a work history, from all patients.
Rationale. An adequate environmental exposure history is needed to assess individual risk for prevention purposes, to identify environmental contributors to symptoms for diagnostic and therapeutic purposes, and to develop a sensitivity to the environmental conditions in a community that may contribute to ill health. The environmental history (including work history) also provides a vehicle for enhancing the patient-physician relationship. It creates an opportunity for patients to bring their own expertise about their workplace, home, and community environments to the relationship.
Physicians routinely elicit past medical, family, and at least partial smoking histories, but they seldom inquire about the details of a patient’s occupational and environmental exposures. Diseases caused by environmental and occupational exposures are frequently similar to diseases of different etiology, and the exposure history is usually the key to distinguishing between them. Specific skills and experience are needed to help accurately identify these etiologic agents. Treatment may be ineffective if the connection is not recognized and the exposure is not controlled; prevention and risk-reduction activities depend on proper hazard identification (see Box 5).
Competency 4. Graduating medical students should be able to identify and access the informational, clinical, and other resources available to help address patient and community environmental health problems and concerns.
Rationale. The environmental and occupational history may elicit information about exposures and conditions unfamiliar to the physician. At a minimum, physicians should know where to refer patients with a suspected environmental problem or concern. If they are willing to pursue the evaluation themselves, physicians must know where to turn for information and assistance. Such resources include written and database sources; colleagues; specialists in occupational and environmental medicine, and in public health; government agencies; employers and manufacturers; and unions and workers (see Appendix D).
Box 5. Asbestos Disease
A 53-year-old woman presented to the emergency room with acute onset of pleuritic chest pain and dyspnea. Chest x-ray revealed a spontaneous right sided pneumothorax, fibrotic changes in her left lung field, and pleural plaques. The patient complained of gradually increasing dyspnea on exertion over several years. Upon close questioning, she recalled that she had helped her husband build two bungalows thirty years ago and that she had held sheets of asbestos while he sawed them to size.
A 42-year-old social worker presented with right side chest pain and dyspnea. Chest x-ray revealed a right pleural effusion, and fibrotic changes throughout the lungs. PPD was positive, so she received a presumptive diagnosis of tuberculosis and was started on therapy. Her symptoms worsened, with rapidly increasing dyspnea. Thoracentesis was then performed and revealed 2,500 ml of bloody, exudative fluid. Thoracoscopic biopsy confirmed the diagnosis of mesothelioma. The patient lived, as a child, near an asbestos mine in Johannesburg, South Africa. Her father worked in the mine, and wore his dusty clothes home from work; he also died of mesothelioma.
Asbestos is an important example of a potent toxin leading to fibrosis and cancer in workers and those exposed through their environment. The pathophysiology of attack on the long fibers by the cellular immune system, and damage to the lungs from repeated degranulation of neutrophils which are unable to engulf the fibers, is a good example of how the interaction between the body’s defenses and the foreign substances cause the disease. Asbestos is only harmful insofar as the immune system attacks, then re-attacks the fibers, thereby damaging adjacent lung tissue. Other environmental chemicals are metabolically activated into potent toxins. Thus, it is always important to consider the metabolic fate of the toxin, the immunological response, the excretion of the toxin, and to take a thorough environmental history.
Adapted from Elmes (1966), Wagner et al. (1960).
See also case study 3 in Appendix C.
Competency 5. Graduating medical students should be able to discuss environmental risks with their patients and provide understandable information about risk-reduction strategies in ways that exhibit sensitivity to patients’ health beliefs and concerns.
Rationale. The public is increasingly concerned about environmental health hazards, and community-based survey data show that physicians are considered the most trusted (but least informed) sources of information about the risks of chemical exposure. The ability to counsel patients about environmental health risks will require a sound knowledge base, an appreciation of the complex nature of patients’ concerns about environmental health hazards, and excellent communication/counseling skills.
Competency 6. Graduating medical students should be able to understand the ethical and legal responsibilities of seeing patients with environmental and occupational health problems or concerns.
Rationale. Many states have reporting requirements for occupational and environmental diseases. Beyond compliance with legal reporting requirements, physicians may have ethical obligations to report environmentally related conditions to local authorities, especially when other members of the public may be at risk. In addition, patients may need their physicians’ assistance in obtaining the compensation and remediation allowed them by law. Physicians should have a basic understanding of their legal and ethical responsibilities and know where to go for help.
CONCLUSIONS AND RECOMMENDATIONS
With the common acknowledgment that the environment is a vitally important factor in health and in a wide range of illnesses, it follows that every medical school graduate should be knowledgeable and competent in the basic elements of environmental medicine. Thus the committee believes that every medical school graduate should master the six competencies in environmental medicine described in this report and integrate environmental and occupational history-taking into daily practice. Employing this knowledge and these competencies will provide a basis for a more appropriate interaction with patients and the community regarding the impact of environmental medicine and will expand physicians’ knowledge and improve their clinical expertise.
The committee believes that developing the ability to obtain a thorough environmental and occupational history is a fundamentally important component of the competencies, because if done correctly, such a history provides the primary information needed for diagnosis, referral or treatment, and prevention of environmental and occupational illnesses and injuries. A focus on the history can, indeed should, lead to the knowledge, skills, and attitudes encompassed in the other competencies. The elements of such a history have been well described, and a variety of forms and tools have been developed for both teaching and practice purposes (Agency for Toxic Substances and Disease Registry, 1992; American Lung Association of San Diego, 1983; California Public Health Foundation, 1992; Connecticut Department of Health Services, 1992; Goldman and Peters, 1981). Appendix A of this report contains a good example of such a history that was prepared by the ATSDR and peer reviewed by several experts in the field.
Direct discussion of the foregoing competency-based objectives continues in Chapter 3, where each competency is discussed in terms of likely access points in the curriculum for their integration and possible teaching strategies. Chapter 4 then considers the general structure and characteristics of medical education today and reflects on both the barriers to and opportunities for introducing these six objectives into the curriculum.