AS scientists chalked out equations and conducted experiments in their study of the atom during the first half of this century, they saw that under the right conditions, vast amounts of energy could be tapped, even harnessed. But they also saw that uncontrolled, the atom's energy could wreak unimaginable destruction. It took the incineration of Hiroshima and Nagasaki to focus public attention on the moral dimensions of the nuclear age.
Nearly 50 years later, science is pulling society in another direction that researchers say has the potential to benefit humanity. Just as the advances in nuclear research enabled scientists to exploit the fundamental building blocks of matter, advances in molecular biology are allowing scientists to manipulate and exploit the fundamental building blocks of organic life. Society urgently needs to consider how far to let applied genetic research run its course and what strictures to place on the application of genetic engineering, particularly to human beings.
These issues came into sharp focus earlier this year when scientists from George Washington University reported cloning several two- to eight-cell human embryos, two of which the researchers continued to grow in test tubes for several days. The the nominal motive behind the experiment was to improve in vitro fertilization techniques, used by many couples who have difficulty conceiving children. But in a subsequent article in Science magazine, Dr. Jerry Hall, who led the effort, added: ``It was clearly just a matter of time until someone was going to do it, and we decided it would be better for us to do it in an open manner and get the ethics discussion moving.''
Some applications of current or predicted genetic-engineering methods should prompt not only discussion but clear guidelines. For example:
* Genetic screening. As medical researchers have pinpointed an increasing number of genes that they identify with various diseases, companies have developed tests to detect the presence of those genes in humans. Unfortunately, according to a report released last month by the National Academy of Sciences (NAS), some workers have lost jobs and others health insurance coverage based on genetic screening. Such discrimination is faulty on several accounts: Test results can be inaccurate; according to many biologists, the mere presence of a ``suspect'' gene is no indication that the traits it carries will ever be expressed; and in an age of data banks and computer networks, test results - faulty or not - could make it difficult for people to shed a dubious label of ``vulnerable,'' despite anyone's best efforts at maintaining confidentiality.
Despite these drawbacks, public support for confidentiality is lacking. In a 1992 survey conducted by Louis Harris and Associates for the March of Dimes, 57 percent of the respondents answered ``yes'' when asked if someone other than the patient has a right to know whether a patient has a genetic ``defect.'' Yet as the number of companies manufacturing the tests expand their range and aggressively promote their use, the opportunities for abuse of such information will multiply. Hence, the NAS was correct to recommend laws tightly circumscribing the use of genetic screening for employment and a ban on the use of screening results as a factor in extending coverage and pricing health insurance.
* Gene therapy. This prospect of modern-day genetics has generated the most public interest. When Harris asked respondents whether they approved of such techniques, 89 percent said they did, although 60 percent acknowledged that they had heard ``almost nothing'' about it. Not surprising, since this is the least developed aspect of biotechnology. Such therapies, specialists say, could involve alterations to a person's genes that then get passed to descendants. Some researchers foresee a time when a ``defective'' gene can be identified and altered either before or after conception to prevent the manifestation of particular diseases.
Yet as knowledge about human genetics expands, so does the temptation to label as abnormal or as a maladies traits that today are seen as ``normal'' physical variations. The issue is not theoretical: Genetically engineered human growth hormones not only have been used for the intended medical purpose, they also have been sought by people unhappy with the size of their children. Indeed, 43 percent of the respondents to the Harris poll said they ``somewhat'' or ``strongly'' approve of using gene therapy to improve the physical characteristics or intelligence levels that their children would inherit.
The idea that genetics can explain and address many of humanity's physical and behavioral ills threatens to reinforce a notion that humans are merely the sum of exchangeable molecules. Such reductionism invites intolerance and social engineering, and it denies man's spiritual nature. Well-considered boundaries on biotechnology's applications must help serve as bulwarks against this outcome.