The Union of Concerned Scientists, founded in 1969 at the Massachusetts Institute of Technology, has since grown into one of the most influential voices on Capitol Hill. Now based in Washington, D.C., the group frequently weighs in on issues related to the environment, energy, and biotechnology.

Margaret Mellon, director of the food and environment program for the group, specializes in studying how biotech is used in agriculture and how it might affect food safety. In a recent interview with BusinessWeek's Arlene Weintraub, Mellon outlined her views on the mission of Ventria Biosciences and other biotech companies that are genetically altering food crops to produce human drugs. Edited excerpts from their conversation follow:

Q: Is the Union of Concerned Scientists opposed to genetically engineering plants to produce human drugs?

A: We're not opposed across the board. It's a technology that should be examined. And we're enthusiastic about using genetic engineering for drug production. We're not so enthusiastic about outdoor applications of genetic engineering to crops.

Q: What exactly is your concern?

A: When you're genetically engineering bioactive molecules -- drugs -- into crops and they're growing outdoors, you must be able to assure those [engineered traits] don't move to food crops. Otherwise you're imposing health and environmental risks.

Q: How might this affect trade with foreign countries?

A: Genetically engineered crops have uneven acceptance around the world. Some people don't want any genetic engineering in their food. If they found drugs in commodity crops, there would be a huge international brouhaha. People around the world have choices -- they don't have to buy from the U.S.

Q: Right now, the U.S. Agriculture Dept. oversees the growing of plants for pharmaceutical production. What are some of the questions that you think need to be answered when it comes to regulatory oversight?

A: We need to look at the ways both the USDA and the Food & Drug Administration are involved. The FDA has authority to oversee drug production. The question is: When does drug production begin here? Is it when the genetically engineered crop is delivered to the biotech manufacturing facility? Or should the FDA's authority extend into the field?

The FDA needs to get new authority from Congress to allow them to regulate genetically engineered organisms. There needs to be a pre-commercial review of the risks inherent in this type of production.

Q: Some companies are developing animals -- such as goats and cows -- that might be able to produce human drugs in their milk. Why hasn't that stirred up the same amount of controversy as drug-producing plants have?

A: The chances of a [captive] goat passing along a drug-producing gene to a wild goat aren't very high. But even there, there are concerns.

We have to make sure the drugs don't carry viruses or other infectious agents. We have to make sure we're not impeding the health and well-being of the animals. And there could be problems with human error -- someone selling one of these animals into the food supply, for example.

Q: It sounds like you're calling for big changes at the federal level.

A: The process we have now just isn't going to do it. People are nervous about genetic engineering. This is not a trivial issue.