THE trouble with the controversy over field-testing genetically engineered organisms is that both sides recognize a basic point but disagree over its significance. They both stress that extensive study has turned up no discernible hazard in the proposed tests. But while field-test promoters find this reassuring, critics consider it a disturbing sign of ecological ignorance. The failure to find a potential hazard may only reflect the inability of scientists to assess the effect of introducing a novel organism into the environment. In the face of ignorance, they advise caution in proceeding with what may seem to be even the most innocuous of field tests.
Thus, Advanced Genetic Sciences of Oakland, Calif., is ready to field-test ice-minus bacteria -- bacteria genetically altered to inhibit frost on plants -- and the Environmental Protection Agency (EPA) has satisfied itself that the company should be allowed to do it. But Jeremy Rifkin, who has long opposed such field tests, has again filed suit in federal court to stop it. He challenges the EPA's contention that it has adequately investigated the ecological hazards, partly because no one yet knows how t o carry out such a study adequately.
Actually, John Moore, the assistant EPA administrator, is probably right when he says any hazard from the proposed ice-minus field tests is ``extremely remote [because] it's a pretty modest experiment.'' This is probably also true of the field test of tobacco engineered to have increased disease resistance, for which Agracetus, a company in Middletown, Wis., obtained approval from the National Institutes of Health (NIH).
The concern of environmentalists such as Rifkin is more for what is about to happen than for these particular tests. The congressional General Accounting Office has identified 87 research projects that will involve field tests of genetically engineered organisms over the next five years. Many commercial companies are also developing a host of new agricultural products, both plants and microbes, through genetic engineering. Thus the introduction of genetically engineered organisms into the environment is
about to develop explosively, well before ecologists are prepared to assess its consequences.
Furthermore, the United States, at least, is ill prepared to regulate this development. Several federal agencies such as the EPA, the Department of Agriculture, the Food and Drug Administration, and NIH are regulating bits and pieces of the work. But neither researchers nor businesses know exactly where to turn for permission for field trials. Indeed, the NIH has indicated it feels it was not the right agency to approve the tobacco tests. Despite much lip service being given to this problem, the regulat ory situation in the United States remains muddled.
Given both the ecological and the regulatory uncertainties, it is little wonder that field tests of genetically tailored organisms meet resistance.
It's impossible today to know what effect the introduction of genetically engineered organisms on such a massive scale may have. We lack an adequate science of predictive ecology. As Cornell University microbiologist Martin Alexander, for example, has pointed out, ``ecologists are unable to predict which introduced species will become established and which will not, and it is often not possible to explain successes or failure after the fact.''
The kind of predictive science needed is illustrated by the work of Gary S. Sayler and colleagues at the University of Tennessee at Knoxville. They are working with EPA funding to develop ways of locating and tracking genetically altered bacteria in the environment. They extract DNA -- the genetic material -- from samples of environmental bacteria. Then they introduce chemical probes, which carry radioactive phosphorus as a tracer and which seek out and attach themselves to the altered DNA in the sample . In this way, they can identify the man-tailored bacterial genes mixed in with all the other bacterial genes in the sample.
Sayler says this is ``a very powerful tool for looking at the ecology of organisms as well as environmental risk and acceptability.'' It's one element in what will eventually be a tool kit for ecologists with which they can develop the knowledge of how to monitor and predict the probable environmental consequences of introducing genetically engineered plants and microbes into widespread use in the field.
But until such a science of predictive ecology is available, even seemingly innocuous field tests are suspect.
Whether or not the trials of ice-minus bacteria or disease-resistant tobacco plants are allowed to proceed, there is a larger and more urgent need for the US to put its regulatory mechinery in order and to help develop a science of predictive ecology. Agricultural genetic engineers are rushing ahead with what will really be a massive experiment in ecological engineering. And right now, neither the US nor any other country can foresee what this may do to the world environment.
A Tuesday column. Robert C. Cowen is the Monitor's natural science editor.