Toxicology and Environmental Health Information Resources: The Role of the National Library of Medicine (1997)

Health professionals need access to environmental health¹ and toxicology information for many reasons. Certainly, public awareness about human health risks from chemical and biologic agents in the environment has increase dramatically in recent years. Similarly, changing trends in health care and an emphasis on prevention, coupled with increasing computer literacy, all support the need for readily available information about the impacts of hazardous substances in the environment on individual and public health. Reports in the popular press and news media have highlighted the public's concern. For example, pesticides on foods; second-hand tobacco smoke; asbestos and lead paint in homes and public buildings; dioxin contamination; occupational exposures to gasoline and other chemicals; exposure to radon and benzene; and drinking water contaminated with biologic and chemical agents are just a few of the issues that may confront the American public.

Although the public relies heavily on federal and state regulatory agencies for protection from exposures to hazardous substances, they frequently look to health professionals for information on routes of exposure and the nature and extent of associated health consequences. However, most health professionals acquire only a minimal knowledge of toxicology during their education and training. As a result, their working knowledge of the adverse effects of chemicals on health and the conditions under which those effects might occur is often limited. Furthermore, with the many competing demands on health professionals' time, it is difficult, even for specialists, to keep apprised of rapidly evolving

toxicology information. Thus, health professionals need ready access to toxicology and environmental health information resources to assist them with patient care. Policymakers, health advisors, researchers, health educators, and other involved communities (e.g., the general public) also need access to this information as they pursue their own inquiries.

Established in 1956 (Public Law 84-941), the National Library of Medicine (NLM) is charged with improving the nation's health by collecting and providing access to the world's biomedical literature. In 1967, NLM established a specialized information program in toxicology and environmental health known today as the Toxicology and Environmental Health Information Program (TEHIP).² Its mission is to provide selected core information resources and services, facilitate access to national and international information resources, and strengthen the information infrastructure of toxicology and environmental health (NLM, 1995). Currently, the TEHIP program encompasses 16 online databases that contain bibliographic and factual information on hazardous substances, including chemical properties, carcinogenicity, exposure levels, adverse health effects, emergency treatment protocols, and federal regulations. Additionally, the TEHIP program is responsible for training and outreach efforts to health professionals.

In 1995, at the request of NLM, the Institute of Medicine (IOM) formed the Committee on Toxicology and Environmental Health Information Resources for Health Professionals. The committee was charged with producing a consensus report examining the utility and accessibility ³ of NLM's TEHIP program for the work of health professionals and providing NLM with recommendations and strategies to improve use of the TEHIP databases. Additionally, the committee was asked to consider the current toxicology and environmental health information needs of health professionals and how those needs are currently being met. To fulfill this charge, the IOM selected for membership on its committee, individuals with expertise in a variety of disciplines, including medical and clinical toxicology, occupational and environmental health, primary care, library science and medical informatics, environmental science, health education, and emergency medicine.

The committee met three times during the course of the study and received extensive input from health professionals representing a range of disciplines and expertise. Input was received through several mechanisms. In conjunction with several health professional organizations, the committee developed and distributed a questionnaire that focused on the current use of computers and of online information resources in toxicology and environmental health (see Appendix B).

The committee received 247 responses to the questionnaire. Additionally, the committee sponsored a workshop during which thirty-four health professionals attended one of four focus group sessions that discussed information needs and information resources in toxicology and environmental health (see Appendix C). Workshop participants also attended a demonstration of the TEHIP databases presented by NLM staff. The committee received valuable input from the speakers who attended its meetings, including NLM staff members, occupational and environmental health specialists, and representatives from several government agencies involved in environmental health issues. In addition, the committee benefited from the work of the 1993 NLM Long Range Planning Panel on Toxicology and Environmental Health (NLM, 1993), which presented many of the issues and recommendations that the IOM committee considered and reaffirms throughout this report.

Although toxicology and environmental health information is used in a wide range of occupations and professional endeavors, including nursing and clinical medicine, pharmaceutical development, chemical manufacturing, environmental engineering, and law, the committee was charged specifically with examining the toxicology and environmental health information needs of health professionals. This charge is in concert with the mission of NLM, which focuses on "the dissemination and exchange of scientific and other information important to the progress of medicine and to the public health" (NLM, 1986). The committee took a broad perspective that encompasses a number of groups with interests in environmental health (see also Chapter 4). The committee realizes that the health professional community does not have homogeneous information needs and there is a wide range of variation in access to online databases and other information resources. Even with these variations, however, the committee believed that it was worthwhile to discuss potential user communities to provide generalized insights into how NLM might better meet the toxicology and environmental health information needs of these groups. The following list of potential user communities is not meant to be definitive or exhaustive but rather was used by the committee for purposes of discussion:

• primary care professionals (e.g., physicians, nurses, nurse practitioners, and physician assistants) and pharmacists;

• specialists in occupational and environmental health (e.g., physicians, nurses, nurse practitioners, physician assistants, industrial hygienists, and safety officers);

• emergency medicine and poison control center personnel (e.g., emergency room health professionals, emergency medical technicians, clinical and medical toxicologists, and specialists in poison information);

• health science librarians and faculty at health professional schools (including medical, nursing, public health, pharmacy, and dental schools);

• environmental health researchers and scientists (including health physicists, epidemiologists, toxicologists, and forensic practitioners);

• patients, the general public, and community organizations (including local emergency planning committees, public librarians, educators, and advocacy and activist organizations); and

• health professionals in local public health departments or in state and federal agencies (e.g., policy advisors, health educators, and public clinic personnel).

Although the type, depth, and frequency of toxicology and environmental health information needed by each of these groups will differ among individuals within and across the groups, depending on job responsibilities, demographics, training, work or practice setting, time, access, and availability, these groupings provide a framework from which to explore information needs, current strategies for finding information, and potential use of the TEHIP databases.

This chapter provides the context for the report by discussing the ways in which both the public health impacts of hazardous substances and the changing trends in health care are reinforcing the need for authoritative and easily accessible information in the fields of toxicology and environmental health.

The proliferation of synthetic organic chemicals has created many hazards to human health and the environment. Furthermore, many of these compounds are persistent in the environment, accumulate in human tissue, and are inadequately tested for both their ecological and human health effects. Pathways of human exposure to chemicals in the environment are diverse. Chemicals in air, food, water, and soil can be inhaled, ingested, or absorbed in any number of settings. Such exposures can occur at home, work, and school, as well as in vehicles, public buildings, and outdoor community environments. Vulnerable populations, such as children, the elderly, the chronically ill, minorities, and the poor may be at increased risk of harm related to environmental contamination because of biologic and demographic factors, including where they live.⁴ The

Environmental Protection Agency (EPA) estimates that one in four Americans (including 10 million children under the age of 12) lives within 4 miles of a toxic waste dump (EPA, 1996).

Determining the human health effects of environmental contamination is a complex undertaking. People are exposed to many chemicals simultaneously, and little is known about the health consequences of multiple chemical exposures (INFORM, 1995; IOM, 1995). Most human studies focus on either occupational groups or clinical cases involving acute poisonings, both of which generally involve higher exposure levels than those experienced by the general population. There is limited information about the health effects associated with low-level chemical exposure over extended periods of time. The technical difficulties of measuring exposure, determining the actual dose to the target organs, and extrapolating data from animal studies to human populations further confound the ability to assess the effects of hazardous substances on human health.

Despite these difficulties, the roles of certain hazardous substances in the development of human disease are well-known (Lybarger et al., 1993). Environmental chemical exposures can affect all organ systems. They can cause or contribute to the development of a variety of human illness, including cancer, asthma and other respiratory diseases, reproductive disorders, neurological and immune system impairments, and skin disease, as well as cardiovascular, renal, hepatic, and psychological disorders (Rom, 1992).

The proliferation of the manufacture, transport, use, and disposal of chemicals coupled with the potential for human exposures makes it essential that health professionals have easy access to resources and information to assist them in the prevention, diagnosis, and treatment of disorders possibly stemming from exposures to hazardous substances in the environment.

In this time of major changes in health care in the United States, many individuals are becoming better informed health care consumers and more involved in their own health care. In assuming a more involved role in prevention and health care, individuals often seek out information that can improve or maintain their health, as well as information about preventing, managing, and treating disease and illness. When patients are unable to independently find or fully understand information related to their environmental health concerns, they may turn to their primary care physician or other trusted health professional for accurate information and answers (IOM, 1988). Since disease prevention is an area of growing interest and activity, it is important that health professionals

be aware of prevention options and knowledgeable enough to counsel patients with possible environmental exposures. Examples of primary prevention efforts in environmental health include reducing radon exposure to prevent lung cancer, installing carbon monoxide detectors, and counseling people with asthma on choice of workplace and recreation. Additionally, right-to-know laws in the workplace and community as well as consumer product labeling place information demands on health professionals as patients, workers, and community groups ask questions about exposure risk and potential adverse health effects.

The rapid growth of biomedical knowledge and the resulting increase in the number of scientific journals that have inundated health professionals are other factors affecting the need for accessible toxicology and environmental health information (Deering and Harris, 1996). Approximately 300,000 new references are added to the MEDLINE database annually (Hersh, 1996). This "information explosion" has resulted in the greater use of computers to store and rapidly retrieve information (Hersh, 1996; Huth, 1989). Additionally, the increasing emphasis on cost-effectiveness in health care has made health professionals aware of the marginal utility of their information-seeking actions and the need to use the most cost-effective mechanism for locating information (Greenes and Shortliffe, 1990). Having authoritative information rapidly available can have a significant impact on health care treatment, particularly in emergency situations where time is the critical factor. Poison control centers are a prime example of cost-effective information resources. As computer applications become the standard in health care, health professionals are becoming increasingly adept at using computers. The use of an evidence-based approach⁵ to health care may increase the emphasis on the analysis of medical literature in clinical decision-making and may have an impact on the use of online bibliographic databases. Thus, the committee believes that both current trends in health care and heightened concerns about environmental health issues are increasing the need for online information resources in toxicology and environmental health.

Chapter 1 has provided a brief overview of the background of this report and the context in which the committee discussed the need for authoritative and accessible information resources in toxicology and environmental health. Chapters2 and 3 focus on the broad spectrum of toxicology and environmental health information resources currently available. Specifically, Chapter 2 provides an overview of NLM's TEHIP program and briefly describes the program's 16 databases, and Chapter 3 focuses on other toxicology and environ

mental health information resources and considers NLM's role in the context of this spectrum of information. Chapter 4 identifies the various groups of health professionals that have an interest in toxicology and environmental health information and examines the methods by which health professionals locate information. Chapter 5 explores NLM's current training and outreach efforts and presents the committee's ideas on future directions to increase health professionals' awareness of the available information resources. Chapter 6 considers the issues involved in accessing and navigating the TEHIP databases and presents short- and long-term recommendations for addressing the barriers faced by database searchers. The final chapter, Chapter 7, discusses programmatic issues that will affect the future growth and development of the TEHIP program and presents the committee's recommendations for tools that will assist health professionals in retrieving the toxicology and environmental health information that they require.

During the course of this study, the committee discussed at length how best to converge NLM's strengths in organizing and disseminating biomedical information with the disparate nature and location of toxicology and environmental health information and the wide variety of health professionals' information needs. The committee concluded that it is critical for NLM to exert its leadership role in biomedical information in the fields of toxicology and environmental health. As will be discussed throughout the report, the committee emphasizes the need for NLM to take a library-focused approach encompassing the full spectrum of toxicology and environmental health information, in addition to the 16 TEHIP databases.

This report presents recommendations to NLM regarding the TEHIP program. Additionally, the committee considered the larger issue of organizing the vast quantity of databases and other information resources on toxicology and environmental health and makes recommendations on establishing central access points for information in this field. As a result, the intended audience for this report extends beyond NLM staff to include government and private-sector information providers as well as policymakers, librarians, and health professionals involved in providing and using toxicology and environmental health information.