Seeds of traditional crop varieties are contaminated with genetically engineered (GE) DNA, according to Gone to Seed, a recent UCS report. Among the many implications of this finding, one has potentially serious human health consequences—the possibility that DNA from crops engineered to produce pharmaceuticals and industrial chemicals ("pharma" crops) may contaminate the seed supply for food crops.

The images above illustrate one of the ways seed contamination by pharma crops could occur. In the first image, a corn seed production field is located downwind from a field growing pharma corn plants. Pharma corn pollen, blown by the wind, pollinates corn flowers (silks) in the seed production field. As a result, some kernels on the ears of corn contain DNA for drugs and the drugs themselves.

Unaware of the contamination, the seed producer harvests the corn seed and sends it to a seed production facility to be processed and bagged. In the second image, a farmer goes to a seed store and buys a bag of contaminated seed, believing she is buying pure, traditional, non-GE corn seed to grow for human food and animal feed.

The farmer plants the contaminated seed in her field (third image), unaware that some of the resulting corn plants—those coming from the contaminated corn kernels—are producing drugs in their leaves, roots, and, most importantly, in the kernels on the ears. (Corn contaminated with pharm crop DNA looks no different to the naked eye than regular corn.)

The farmer harvests the corn—some of which is now pharma corn—and sells the crop, which is processed into consumer items such as corn chips, corn meal, and corn flakes (fourth image). Consumers are unaware that they are serving their kids drug-laced corn flakes.

The federal government's regulations of pharma crops do not address the possibility that pharma crops could contaminate seed production. Without stronger federal oversight, the contamination scenario depicted in this example is likely to come to pass.