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Introduction: Genomics, Environment, and Health
On June 26, 2000, two independent groups of scientists announced that they had completed the first draft of the entire sequence of the human genome, identifying the sequence of every human gene and its location on the chromosomes, except for some minor gaps that should be filled in within the next year or two. That accomplishment received widespread attention in the popular media and has been hailed—rightly—as a landmark in human history and the beginning of a new era in understanding the human body and mind.
More broadly, however, this milestone in the Human Genome Project is but one step in a biologic revolution that is likely to transform many sectors of human life. Over the next decade or so, researchers will assemble the genomes of most of the organisms important to humankind, from crop plants and farm animals to disease-causing viruses and bacteria, and of a number of organisms used mainly in research. The information contained in these genomes might give scientists, physicians, and others tools they need to improve the human condition in various ways. Some of the applications are well known and have been discussed at length in the mass media. It might be possible, for example, to treat and eventually wipe out many genetic diseases, such as cystic fibrosis and Huntington disease. Farmers using genetically engineered crops might be able to grow more nutritious food in greater quantity, at lower cost, and with less damage to the surrounding environment than is possible now. And pharmaceutical companies might be able to design more-effective vaccines and drugs for the treatment of infectious diseases.
There is at least one other application of genomic information, less well known, whose implications are potentially equally profound, and it warrants
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equal attention. For decades, physicians and researchers have known that environmental contaminants—radioactive wastes, heavy metals, toxic chemicals, and so on—play a role in human diseases, including cancers, neurodegenerative disorders, and birth defects. But the threat posed by these contaminants has proved complex and difficult to resolve. On the environmental side, for instance, cleaning up contamination is often frustrating and expensive, especially when the contaminants are spread through many square miles of ground and in large underground aquifers, as in large-scale contaminated sites. On the human-health side, how a person's body responds to an environmental insult depends heavily on the person's genes, and there is some degree of variation from person to person in vulnerability to environmental contaminants. That variability complicates the analysis, treatment, and prevention of environmentally triggered diseases, and scientists often find it difficult to answer even such seemingly simple questions as whether a cluster of cancers in one small geographic area occurred by chance or was caused by exposure to some environmental carcinogen.
The coming flood of genomic information could change all that. Environmental cleanup, for example, might be greatly aided by the ability to genetically engineer plants and bacteria to remove some contaminants from soil and water. On the medical front, researchers believe that having the complete human genome to work with might help them understand how environmental contaminants lead to cancers and other diseases and to figure out why some people are more susceptible than others. Ultimately, both prevention and treatment could be transformed by the insights that stem from genomic information.
The genomic revolution can also be expected to have ramifications outside science and medicine. It might have consequences, for example, for the court system, where citizens and corporations go to determine who has been harmed by environmental contamination, who is at fault, and how much compensation is owed for the harm. Judges and juries are already straining to comprehend the scientific evidence in some cases; how will they respond to a deluge of new, complex information that they must digest to reach a verdict? The new, more complete genomic information that is coming will once again raise the issue of genetic discrimination in hiring decisions and health insurance. Should the government, for instance, allow companies to use information about a person's susceptibilities to environmental contaminants in hiring and insurance decisions? And how might the new genomic information change how people think of disease? If it becomes possible to trace the development of a disease from the first environmental insult through each of the intermediate stages to the point where it can be identified as a recognizable syndrome, then disease might come to be seen not in terms of black and white or off and on, but as one end of a spectrum.
Because of the importance of this complex set of issues, and because they have seldom been analyzed as a whole instead of as separate pieces, on August 16, 2000, the National Academies' Board on Life Sciences held a one-day forum, “Environmental Contamination, Biotechnology, and the Law: The Impact
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of Emerging Genomic Information.” Sixteen speakers, representing the scientific and legal professions, gave presentations ranging from a primer on science in the courts to detailed descriptions of how genomic information can be applied in bioremediation. The forum agenda and biographical information on the speakers can be found in appendixes A and B, respectively. Discussion periods and question-and-answer sessions allowed the invited speakers and audience members to exchange ideas and information and to flesh out some of the topics introduced in the talks.
The following is a summary and synthesis of the information presented at the forum. It is divided into three sections covering health, environmental clean-up, and legal issues. Each section can be read independently, but the third will make more sense if the reader is at least familiar with the subjects in the first and second.
