As gene-tailored organisms increasingly move from laboratory to field test, there is little environmental risk in the small-scale tests so far carried out or planned, according to the Office of Technology Assessment. But the congressional agency warns that the United States needs a better way to assess the risks and regulate experiments before such organisms move on to bigger field tests and commercial use.
In a review of field-test issues released May 4, the congressional office cites basic scientific ignorance of relevant ecological effects as the most significant challenge experimenters and regulators face.
``Taxpayers are investing much to develop science and technology, but relatively little to develop means for the safe and wise application of such knowledge,'' the review notes.
This is the knowledge needed to set up the kind of field-test regulation the technology assessment office is urging Congress to consider.
Reflecting recommendations made earlier by the National Academy of Sciences, the office suggests ranking proposed field tests according to their degree of probable risk and regulating them accordingly.
Tests posing minimal risks - such as those involving small changes in crop plants or other organisms already widely used - would receive less scrutiny than those involving novel organisms with unknown and possibly serious ecological impacts.
Some such strategy of focusing risk-assessment resources where they are most needed has to be adopted or regulators will be swamped as field tests proliferate, the report explains.
The new report - Field-Testing Engineered Organisms - is the third in a series of reports called New Developments in Biotechnology that Congress asked its advisory agency to produce. Earlier reports dealt with ownership of human tissues used in experiments and with public perceptions of biotechnology.
Although the report is designed to help Congress deal with the field-testing issue in the US, its assessment has global usefulness.
Many countries face environmental challenges in trying to develop this promising new technology. Some two dozen field tests have already been carried out in 5 countries, including the US. Many more are planned.
Testing involves medical and veterinary trials of vaccines and other treatments derived through genetic engineering.
But the main concern in field tests is with the ecological risks of releasing modified plants, animals, and especially microbes for agricultural purposes.
These organisms are intended to become part of the living community of crops and livestock. If they evolve in unexpected ways or escape to become part of the wider biological communities beyond the farm, experimenters and regulators want to be sure they do not cause significant ecological harm.
As the Office of Technology Assessment notes, altered crop plants and livestock ``are widely, though not universally, considered to be relatively safe for release.'' These raise less concern than do altered microbes - bacteria and viruses - which multiply rapidly and evolve quickly.
Altered microbes are being studied for many purposes such as pest control, enhanced nitrogen fixation, and even frost control in the case of the so-called ice-minus bacteria that help prevent frost formation when living on plant leaves.
The report notes that use of such organisms offers many benefits, including replacing chemical pesticides with more benign pest-control bacteria.
But, the agency emphasizes, the key to getting these benefits is building the base of ecological knowledge on which to set up a regulatory system in which people can have confidence.