Informing the Future: Critical Issues in Health, Third Edition (2005)

We live in a world filled with risks—and we always will. Going about our daily lives, we encounter risks ranging from illness due to E. coli 0157, to an adverse reaction to a medicine, to skin cancer caused by exposure to the sun, to death by a terrorist act. These and many other risks are real, but vary enormously in their probability of occurrence and the magnitude of their effects. Similarly, the public’s perception of risks and their probabilities varies dramatically, and sometimes is not aligned with what the evidence tells us. The Institute of Medicine (IOM) has played critical roles over the years in going beyond perceptions of risks to evaluate the evidence on a wide range of risks and their likelihood, and then communicating these evidence-based findings to the public and to decision makers.

Mold has been extensively reported in the media as the likely culprit in a wide array of routine and exotic illnesses. Since almost all homes, apartments, and commercial buildings will experience leaks, flooding, or other forms of excessive indoor dampness at some point, the issue of health risks associated with damp spaces has emerged as a major public health and legal controversy, as concerns have grown that excessive dampness can cause or contribute to a host of adverse health effects. In light of such concerns, the Centers for Disease Control and Prevention (CDC) asked the IOM to examine what is known about potential links between dampness and health and to propose public health responses as needed. Damp Indoor Spaces and Health (2004) concludes that current scientific evidence is sufficient to link exposure to damp conditions and exposure to molds commonly found in damp environments to asthma symptoms in some people with the chronic disorder, as well as to coughing, wheezing, and upper respiratory tract symptoms in otherwise healthy people. However, available evidence does not support an association between either indoor dampness or mold and the wide range of other health complaints that have been ascribed to them.

Given the frequent occurrence of moisture problems in buildings and their links to respiratory problems, this issue should be addressed through a broad

range of public health initiatives and changes in how buildings are designed, constructed, and maintained. Technical information already exists describing how to control dampness, but architects, engineers, building contractors, facility managers, and maintenance staff do not always apply this knowledge. To help promote improvements, consensus guidelines for preventing indoor dampness should be developed at the national level, under the aegis of either a government agency or an independent nongovernmental organization. In addition, governments at appropriate levels should review building codes and modify them as necessary to reduce moisture problems.

The report’s conclusions regarding health effects are rippling through the legal community. In a comprehensive review in the journal Mold, two leading environmental lawyers say the report will significantly affect toxic tort litigation nationwide, especially cases that involve exposure to household mold. Calling the report “by far the most comprehensive study presently available on the issue,” the authors say it “significantly brings into question whether there is sufficient evidence to demonstrate the requisite causation necessary to meet the burden of proof in mold litigation.” In most litigation of this type, plaintiffs rely on expert witnesses to testify that mold is causally responsible for their claimed health effects. Given the IOM report’s exhaustive review of available scientific evidence, however, the authors suggest that plaintiffs’ experts will have difficulty finding credible studies on which to base an opinion that mold and damp indoor environments can cause adverse health effects beyond those described in the report.

Indeed, the report already has entered the courtroom. In Arizona, the owners of an apartment building successfully defended themselves against a tenant’s claims that exposure to mold in her apartment caused brain injury, seizures, and several other neurological and immune disorders. In its ruling, the U.S. District Court hearing the case cited the report’s conclusions in rejecting expert testimony that sought to establish causation between the presence of mold and the plaintiff’s symptoms.

Damp Indoor Spaces and Health also is contributing to scientific and medical discussions. Participants highlighted the report at the Surgeon General’s Workshop on Healthy Indoor Environments, held in January 2005. In addition,

the American College of Physicians summarized the report’s health conclusions in CHEST, the group’s online journal, and several environmental publications, including Environmental Health Perspectives, have covered the report in news articles.

Smallpox, historically one of the most dreaded and deadly infectious diseases, was eradicated in 1980 with the help of universal vaccination of children and strategic vaccination campaigns in the developing world. With the disease no longer a threat and smallpox virus remaining in only two laboratories (in the United States and Soviet Union, now Russia), routine vaccination ended. However, the fall of the Soviet Union occasioned concern that smallpox virus stocks could have fallen into the wrong hands. The events of September 11, 2001, and subsequent anthrax attacks created an environment in which fears of bioterrorism led to calls to prepare the country against potential threats,

including the possibility of smallpox, a disease against which most Americans are not immune.

In December 2002, the federal government announced that smallpox vaccination would be administered to certain high-risk military personnel and would be offered on a voluntary basis to select civilian public health and medical professionals, emergency response personnel, and others who would be “first responders” in a smallpox emergency. This was an unusual policy decision: to vaccinate people against a microbe that no longer exists (outside of two laboratories) with a vaccine that poses some well-known risks. The smallpox vaccination program presented a case study at the intersection of public health and national security—two fields brought together by the threat of bioterrorism. Bioterrorism attacks epitomize “low-likelihood, high-consequence” events, and preparing for them is challenging. Efforts to prepare for an event that may never occur are likely to come under criticism if the threat never materializes. Also, such events are accompanied by a high level of uncertainty, including an unclear ratio of risk to benefit. For this reason, implementing a program of preparedness for bioterrorism and similar types of events requires careful consideration of information and communication needs.

As the federal agency charged with administering the public vaccination program, the CDC turned to the IOM for guidance on selected aspects of implementation and evaluation. In a timely manner, the IOM issued six letter reports to help guide the program and its integration into the broader public health preparedness efforts. The seventh and final report in the series, The Smallpox Vaccination Program: Public Health in an Age of Terrorism (2005), discusses lessons learned that can inform not only the operation of the smallpox vaccination program but also other public health efforts to prepare for terrorism. The report concludes that it is not possible to determine the level of smallpox preparedness in local jurisdictions and nationally, because the CDC did not systematically assess program outcomes. In order to gain such understanding, the CDC, in collaboration with state and local partners, should set specific goals for preparedness that reflect the best available scientific and public health reasoning; conduct regular, comprehensive assessments of preparedness at the national level and by state; and communicate to the public about the status of preparedness efforts. The CDC also did not communicate vital information to key constituencies

expected to play vital roles in the program, such as public health and health care administrators, and this gap limited the program’s success. The numbers of individuals vaccinated fell far short of the CDC’s goals, and the program had very little support among the key constituencies essential to its success. Based on these lessons, the report concludes that in future efforts to prepare for bioterrorism, public health officials and policymakers should develop strategies to balance national security imperatives—such as protecting classified information—with the need to provide key constituencies and the broader public with appropriate explanations and guidance about a program’s rationale, implementation, and objectives. In the absence of complete and credible information, the public’s perception of risks and benefits will be driven by rumor and media rather than good science.

Genetic engineering is one of the newest technologies available for producing desired traits in plants, animals, and microorganisms used for food. Put simply, genetic engineering uses molecular biology techniques to delete unwanted genes or to transfer desirable genes from one species to another. Today, genetically engineered foods (GE foods), including some cereals, snack foods, and soft drinks, have become more common. GE foods have not been found to pose adverse health effects in humans. But current evidence suggests that any technique for genetically altering plants and animals—whether by genetic engineering or more conventional breeding methods—carries the potential to result in unintended changes in the composition of the food, such as the addition of new toxins or allergens. Safety of Genetically Engineered Foods: Approaches to Assessing Unintended Health Issues (2004) proposes a new framework for examining, identifying, and evaluating systematically the compositional changes and potential health effects of all genetically altered foods, including GE foods, before they are sold to the public. The report, issued jointly by the IOM and the National Research Council, calls for federal agencies to assess the safety of all

genetically altered foods on a case-by-case basis, regardless of the method used to create them. The evaluations should place the greatest scrutiny on determining whether an altered food product contains new compounds or unusual amounts of naturally occurring substances that exceed the range of recommended or tolerable intake. Foods warranting further evaluation should under-go more detailed safety assessment prior to their commercialization, and post commercialization monitoring should be conducted to spot any problems that may arise over the longer term. Failure to exercise diligence in review and regulation of genetically altered foods could risk loss of public confidence and a rejection of GE foods, as has been experienced in Europe and Africa.

The rapidly growing use of the hormone testosterone among men in the United States has outpaced the scientific evidence about the therapy’s benefits and risks, especially the risk of developing prostate cancer. The Food and Drug Administration (FDA) has approved testosterone products for treating a limited number of conditions, particularly hypogonadism, and researchers have carefully evaluated this form of therapy, used primarily by younger men. Far fewer clinical studies, however, have been conducted in middle-aged and older men who are turning in increasing numbers to testosterone therapy in an effort to counter the effects of aging. Now, the National Institutes of Health and other research organizations are considering clinical trials to assess the use of testosterone in these populations, and the National Institute on Aging and the National Cancer Institute turned to the IOM for guidance.

Testosterone and Aging: Clinical Research Directions (2003) presents a road map for how clinical trials should proceed. Initial studies should focus on determining the efficacy of testosterone therapy in older men and the nature and extent of the risks and benefits. In a coordinated set of trials, several hundred men 65 years and older should be monitored for 1 to 2 years to determine whether testosterone is effective in treating specific conditions. Limited preliminary evidence suggests that testosterone may help improve strength, sexual function, cognitive function, and general well-being. If testosterone proves effective, then a large-scale trial involving several thousand men followed over a longer time frame is warranted. All studies should involve only

men who have been diagnosed with low testosterone levels and at least one symptom that might be remedied by the therapy, and who are not a high risk for developing prostate cancer or other prostate problems.

Consumer use of dietary supplements has increased significantly in recent years. Estimates are that more than 29,000 different supplements are on the market and an average of 1,000 new products are introduced annually. Supplements are widely promoted for virtually every health concern, and the public has little scientifically grounded information about their safety or effectiveness. The Dietary Supplement Health and Education Act of 1994 requires that supplements be regulated as if they were foods, not drugs; that is, they are to be presumed safe and are not required to be clinically tested before being marketed. The Food and Drug Administration must prove that a particular supplement presents an unreasonable health risk in order to remove it from the market. In order to improve its ability to assess the safety of both traditional and new supplements, the FDA turned to the IOM for assistance.

Dietary Supplements: A Framework for Evaluating Safety (2003) proposes a science-based process for assessing safety, even when data are scarce. The proposed process consists of three steps: reviewing readily available information to screen for potentially hazardous substances; prioritizing those substances that require the most immediate attention; and then conducting individual in-depth safety evaluations, which would be based on collecting and reviewing additional data (including from industry). The report also calls on Congress to require manufacturers and distributors to notify the FDA in a timely manner of any supplement-related health problems that they discover once products are on the market. To further boost reporting, labels on supplements should include a toll-free number that consumers and health professionals can use to report problems. To meet the growing challenge of ensuring the safety of supplements, the FDA

will need sufficient funding to collect and analyze data and to carry out its various protection and education activities.

Lifestyle choices—including smoking, alcohol consumption, poor diet, and physical inactivity, among others—are known to affect health and well-being. But to what extent? The answer will influence priorities for investing public funds, public policies, and individual lifestyle decisions. In recent years, the CDC and other organizations have attempted to quantify and interpret the contributions of lifestyle-related factors to preventable death. In 2004, the CDC published a study in the Journal of the American Medical Association that estimated the numbers of preventable deaths linked to a range of lifestyle choices—and controversy emerged, about both the study’s conclusions and its methodology.

At the request of the CDC, the IOM convened a workshop to bring together experts in a variety of disciplines to review methodologies and explore broader scientific challenges involved in assessing the health effects of lifestyle choices. Estimating the Contributions of Lifestyle-Related Factors to Preventable Death (2005) summarizes the deliberations. No “perfect” solution emerges, but participants identify four areas where advances would be valuable. These areas include reframing the debate (although ideas differ on parameters); improving methodology (including identifying critical gaps in data, methods, and estimates); developing an action plan (including steps to improve research methods, communicate findings, and develop interventions that would exert an impact on public health); and guiding public policy and creating public health messages that provide understandable information that neither understates nor over-states the risks related to particular lifestyle choices.