New evidence of problems with use of GMOs (24/9/2003)


Genetic Engineering Policy and Science since the Royal Commission: No Resolution of Problems in Sight

Peter R Wills, BSc, PhD
Department of Physics, University of Auckland, Private Bag 92019, Auckland; <[email protected]>; telephone 64 9 373 7599, Extension 88889; Fax 373 7445.

Summary of Analysis

Relevant new evidence has appeared since the Royal Commission on Genetic Modification (RCGM) delivered its report.  The report was deficient in its expectation of what further research was likely to uncover or how events would unfold.

There is growing recognition that some of the general problems that were raised in criticism of the use of GE organisms, especially as crops and in food, are more serious than initial enthusiasm for the technology, and the Report of the RCGM, would have indicated.   Recent international scientific reports have renewed scepticism concerning assessments of the safety of GE food and of the effects of GE crops on agricultural and natural ecosystems.

The RCGM downplayed evidence expressing concern of inevitable contamination of conventional crops if GE crops were allowed to be grown in New Zealand.  The RCGM expressed no overriding concern about the inability of scientists to assess the risk of unexpected effects caused by genetically engineered organisms in the environment, or devise ways to manage the harm eventuating from them.

Recent experience with seed imported from the North America to New Zealand has demonstrated the wide extent of GE contamination in grain and seed stocks in that region.  The contamination of non-GE crops due to outcrossing from GE crops can no longer be regarded as a potential problem that ought to be mitigated.  Whenever GE crops are grown or harvested near non-GE crops, contamination seems inevitable.  There is growing recognition that seeds can be carried long distances on farm machinery, and by other means, to cross with relatives, making the containment of transgenes virtually impossible.

The RCGM served the interests of GE industries by refusing to endorse a GE-free policy under which the normally accepted level of contamination would set at zero.

The RCGM recommended that the precautionary threshold for releasing genetically engineered organisms into the open environment in New Zealand should be lowered.  Establishing the category of Conditional Release will create new opportunities for GE-based agriculture while effectively ensuring that the opportunity of maintaining the current GE-free status of enterprise will be lost.

Conditional Release will require the public to accept involuntarily the possibility of an increasing level of GE material in some foods, even when they are certified organic or GE-free.  The final effect of new legislation will be to establish a more permissive regime for the growing of transgenic species in the open environment.
Summary of New Opinion

The report of the Expert Panel on the Future of Food Biotechnology of the Royal Society of Canada recommended adoption of a much more precautionary approach to the approval of GE crops than that of the RCGM. The Panel also expressed serious concerns about the undermining of the scientific basis for risk regulation due to growing conflicts of interest within the scientific community.

The Lancet warned of the possible undesirable effects from GE crops stating that they may threaten biodiversity, decrease the richness and variety of foods, and make farmers dependent on chemical and biotech companies.  Health concerns mentioned were allergenicity, gene transfer, especially of antibiotic-resistant genes, and the movement of genes from GE plants into conventional crops.

A report by the Royal Society (UK) said that the way genetically-modified food is tested for safety in Europe must be improved before any new GE plants are declared fit for human consumption.

American Scientist has published a review warning of the difficulties in measuring the risks of possible environmental impacts, including increased reliance on herbicides, the creation of new pests, harmful effects on non-target species and the disruption of ecosystem processes.

Summary of New Reports and Findings

Initial results from very large farm trials of GE crops conducted in the UK confirm that there are all sorts of secondary effects generated when apparently minor genetic modifications are made to plants.

Potatoes engineered to deter one pest have been found to attract another, demonstrating the virtual impossibility of taking account of all of the ecological consequences of making small changes in the biochemistry of an organism.

In India, GE cotton under drought conditions has been a failure relative to non-GE cotton.

Five years after authorities exempted the coat protein of the Papaya Ringspot Virus from restrictions on its production in GE fruit, new bioinformatic screening techniques show that it is a potential allergen.

Roundup Ready soybeans contain DNA that its creators did not know they had introduced into it.

A British study has reported GE material found in honey two miles away from GE crops.

Traces of genetically modified grains, especially soybeans and corn, are repeatedly creeping into US wheat supplies.  Similar problems are surfacing in Australia.

A biotechnology firm failed to follow US government regulations for the containment of corn that had been engineered to produce a pig vaccine. As a precaution, 63 hectares of nearby corn were ordered destroyed, as were more than 17.5 million L of harvested soybeans.

UK farm trials of GE crops were suspended for a time after it was discovered that illegal GE canola had been mixed with other GE crops grown in 14 fields in England and Scotland.

A study has shown that genes move reasonably readily from wheat to jointed goatgrass, a major weed in wheat-producing areas of western US.

Weeds that have acquired resistance to more than one herbicide have been reported in Canada.

Experimental studies confirm that genes passing from crops to weeds can persist for generations, rather than disappearing quickly due to the lack of any positive selective pressure.

Commercial transgenes, or parts of them, have found their way into native maize in remote locations of Mexico.

A theoretical study of the effects of specific novel genes in crops shows how wild plants are threatened by gene flow from crops.

The direct transfer of genes from bacteria to mammalian cells has been demonstrated.

The natural trafficking of genes between chloroplasts and nuclei has been found to occur rapidly, scotching one of the methods proposed to contain plant transgenes.

In the past seven years, several weed species have been found with Roundup resistance.

Differences have been found in soil microbial communities around GE canola and conventional canola.

It has been found that some Bt-resistant insects are actually able to digest and utililise the toxin protein, potentially increasing the fitness of resistant populations.

At low toxin levels Bt-resistance is inherited in a codominant or weakly codominant rather than recessive fashion, making refugia potential liabilities rather than assets.

According to US government figures nearly one-fifth of farmers in the midwest are ignoring federal rules concerning refugia.

The Bt toxin exudes from the roots of plants and accumulates in soil, and retains insecticidal activity for at least 6 months, bound to particles in the soil.

Bt corn, especially one that expresses toxin at high levels, appears to damage non-target monarch and black swallowtail caterpillars in the wild. 


Continuation of the moratorium on applications for the release of genetically organisms into the environment of New Zealand is probably the only way to preserve our opportunity of remaining virtually free of contamination and other problems associated with GE crops.

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