Is molecular “pharming” a potential hazard tothe environment?

Plants and animals are being genetically engineered as “biofactories” (“pharms”) to express a spectrum of biomolecules (e.g., antibodies, vaccines, hormones, blood substitutes, toxins, other pharmaceuticals) for numerous therapeutic purposes, as well as for industrial uses (e.g., enzymes). The release to the environment of these transgenic organisms, which contain foreign genes from human beings, other animals, and other organisms, may pose a hazard to the environment. For example, the continual production of these biomolecules in the tissues of plants could result in their accumulation to concentrations that may constitute a hazard to other organisms in soil, waters, and other ecosystems into which the biomolecules will be released in root exudates, biomass, pollen, etc. Accumulation, as well as persistence, will be enhanced if these biomolecules are bound on surface-active particles (e.g., clays, humic substances) in the environment and, thereby, are rendered less accessible for microbial degradation, as has been shown for the insecticidal proteins from Bacillus thuringiensis, which retain toxicity when bound.