Give it a myth: the big assumptions about GM

Several myths, misconceptions and assumptions about genetically modified organisms and food have made their way into the public arena. What doesn't help the average punter to get a grip on the science is that there are huge swathes of information available, from scientists, policy-makers, lobbyists and industry. And for every opinion exists its opposite.

Craig Cormick, public awareness manager at Commonwealth government agency Biotechnology Australia, says many of the so-called myths are half-truths. "It depends on who you ask," he says. "This dates back to any scientific debate on risk and safety."

Prof Adrienne Clarke, Victoria's biotechnology ambassador and personal chair in the University of Melbourne's Department of Botany, says that the adoption of any new technology is always difficult.

"With all technology, it is important that we base decisions on sound science that has been peer-reviewed," she says. But she cautions that science will not convince everyone.

So - on with the myths.

1. GM crops will feed the world

A popular statement made by the pro-GMO camp is that GM crops will feed the world. Not so, according to Bob Phelps of the GeneEthics Network and Scott Kinnear from Biological Farmers Australia (BFA), who say that there is already enough food being produced in the world to feed its burgeoning population.

"I term this one of the big myths," says Kinnear. "Feeding the world will not be as a result of technological improvements, it will be as a result of economic and social reform."

While Adelaide University's Prof Peter Langridge agrees that economic and social reform are needed, he believes that claiming there is already enough food to feed everyone is a fatuous argument.

He notes that in many developing countries, including much of sub-Saharan Africa, the probability of crop failure in any given year is around 30 per cent.

"If we can develop crops that can address yield stability, that will reduce crop failure," he says.

Langridge says international agricultural organisations like CIMMYT - the International Maize and Wheat Improvement Centre - see GM technology as crucial to developing better crops for the developing nations.

He and his colleagues in the CRC for Molecular Plant Breeding are collaborating with Mexico-based CIMMYT on a range of projects. He says that they hope to start field trials on promising drought-tolerant wheat strains soon.

The Food and Agriculture Organisation (FAO) of the UN has recognised the benefits of biotechnology, including the development of GM crops and transgenics as having the potential to increase production and productivity in agriculture, forestry and fisheries.

The FAO also recognises the fact that much of the investment into GM technology concentrates in the private sector and is aimed at benefiting wealthy agricultural nations, rather than developing countries.

2. GMOs are strongly regulated

Regulation of GMOs is another one of the hot issues and again, opinions are polarised. "It's really hard to rate [regulatory requirements] as the spectrum is so great across the world," says Langridge.

Langridge believes Australia's regulatory system, administered by the newly formed Office of the Gene Technology Regulator (OGTR), is very strict relative to other developed countries, including Germany and the USA. He also finds it bureaucratic and over-political.

Clarke also sees the Australian system as stringent. "It is fair to say that getting regulatory approval for a new GM crop is tougher, and requires more extensive testing, than getting approval for a new conventional crop," she says.

BFA's Kinnear, on the other hand, doesn't think that GM technology is well regulated at all. He doesn't like the fact that a lot of the research in submissions to the OGTR and to the Australia and New Zealand Food Authority (ANZFA), who control the use and labelling of GM products in food, is performed by the applicant or their sub-contractor, and would like to see more independent assessment.

"There are still many holes in the system," says Elaine Attwood, a consumer advocate who also serves on the Gene Technology Community Consultative Committee of the OGTR. "For example, when a GM crop is approved for trial, the exact location is not known until after seeding commences - not even the regulator knows. This does nothing to protect neighbouring properties growing non-GM crops."

3. GM is safe and has been well tested

One of Kinnear's big problems with this statement is that he believes there is not enough work done to assess human health and safety risks. "There have been virtually no long-term assessments of risks, no human health trials, monitoring of allergies or cancer," he claims.

But Dr Michael Dack, spokesperson for ANZFA, stresses that GM foods approved by ANZFA have to be rigorously tested before approval. "All GM foods must undergo a safety assessment by ANZFA before the foods can be legally sold in Australia and New Zealand. ANZFA will not approve a GM food for sale if it is less safe and less nutritious than its non-GM counterpart," he says.

Clarke says the initial concern for effects on human health has not been substantiated. "There is no theoretical reason why inserted DNA should have any different effect than DNA which we eat every day in our conventional foods," she says. "Nor have there been any reported health effects from the millions of people who have been eating foods derived from GM plants for several years. In contrast, there are thousands of deaths each year from eating conventional foods which have been contaminated with certain bacteria which cause food poisoning."

Langridge also believes that GM foods are extremely safe. "I would trust GM food more than conventional food as it is much more rigorously tested," he says. "The vast bulk of research indicates there are no safety issues."

Many countries and scientific societies around the world have conducted enquiries into possible adverse effects of eating food derived from GM crops; to date no report has uncovered any evidence to support the view that there might be harmful effects. But consumer advocate Attwood believes that we should be proceeding with caution on this front.

"In truth, how can you expect to find illness when you are not looking for it - and we don't," she says.

4. GM crops will deliver increased profits to farmers

The use of Bt and herbicide resistant cotton strains in Australia have provided some benefits to the cotton industry in Australia, according to Dr Greg Constable, leader of CSIRO Plant Industry's Cotton Improvement and Production program.

He says GM technology ends up costing about the same as the pesticides that would be used otherwise, and in addition, farmers can produce crops in locations and conditions that would have had poor yields otherwise.

But the jury is still out on whether GM will deliver increased profits.

"The OGTR is responsible for health and the environment, but no one is responsible for the long-term viability of farmers," says Julie Newman, a seed grower and farmer from Western Australia.

Her argument is that farmers stand to lose their market if they switch to GM crops before there is consumer acceptance. "Until consumers change their minds, there's a problem," she says.

"There is no process to assess the economic impact of GM in Australia, and there should be," says Kinnear. He points out that while there may be management benefits to using the technology, it disappears if there is no market for the product.

5. GM crops will be good for the environment

Environmental impact of GM crops is one of the big issues for both sides of the argument. Many of the media reports of the last few years have focused on the issue, and there are many conflicting points of view.

A recent paper in Nature Biotechnology surveyed the scientific literature on environmental impacts of GM crops versus conventional crops, examining issues including toxicity, persistence and invasiveness of crops, gene flow, reduced efficiency of pest, disease and weed control, biodiversity and effects on soil and water. While the authors found no compelling differences between the impact of GM and non-GM crops, they advised caution and development of creative management techniques to ensure that GM crops do not become a problem.

Langridge believes that the fundamental problem with many of the arguments is that they are related to how people see agriculture generally, rather than specific to GM crops. "Using GM to prop up unsustainable agriculture is more to do with the fundamental issues of agriculture," he says.

Kinnear says that most of today's GM crops are either of very little benefit to the environment or may have short-term benefits but not necessarily long-term benefits. "There may only be a five to 10-year window before resistance builds up and we are forced to go back to chemicals."

Proponents of GM technology say that crops can be developed that get higher yields from smaller areas, allowing environmentally sensitive areas to be rehabilitated. On the other hand, the anti-GM side suspects that engineering crops to be salt or drought tolerant might expand farming areas into previously untouched environments.

CSIRO has embarked on a cross-disciplinary project to look at the ecological implications of GMOs.

Kent Williams, from CSIRO Sustainable Ecosystems, says the project was seen as something that needed to accompany GM developmental work at CSIRO.

According to Williams, there are three arms to the research. One area looks at theoretical risk analysis and tries to develop theory and models for risk assessment of GMOs. A second arm is considering risk in current GMOs, including those that are still at the bench and glasshouse stage of research as well as the crops that have been approved for field trials and commercial release. The third area is looking at developing new methods to examine environmental risks, so that potential problems can be anticipated and possible hazards identified before trials start.

"This is a program that a lot of people are looking to for answers," says Williams. "We anticipate that by 2003, we will have made significant progress in various areas."

Some of the projects underway include examination of the risks associated with release of "daughterless" carp, analysis of the risks associated with release of herbicide resistant canola and the impact of Bt cotton on beneficial arthropods and non-target species.

"You can't generalise that GMOs collectively are this or that," cautions Williams. "You have to treat them on a case-by-case basis."

6. GM crops use less pesticide

Two varieties of GM cotton have been commercially produced in Australia in the last couple of years, both from Monsanto. Ingard cotton contains a gene from Bacillus thuringiensis (Bt) that protects the plant against attack by insects, while Roundup Ready cotton is tolerant to the use of the broad-spectrum herbicide Roundup (glyphosate).

According to CSIRO Plant Industry's Dr Greg Constable, who heads the Cotton Improvement and Production program, the two varieties have resulted in a 40-60 per cent reduction in the use of pesticides for cotton production in Australia. As GM cotton accounts for 30 per cent of the cotton crop in Australia, this is equivalent to approximately a 15 per cent decrease overall.

While some critics have pointed out that Roundup Ready cotton requires the use of Monsanto's herbicide Roundup, Constable says Roundup is far more environmentally safe than other herbicides as it is broken down in the soil, rather than leaving residuals that can contaminate a wide area. Constable also says the reduction in pesticide use is more pronounced for Bt cotton in Australia than in the USA, as the USA has less insect pressure. GM soybean farmers in the US have reduced their pesticide use from 3.25 million kilograms of a range of herbicides (including some that are three times as toxic and persistent in the environment), to 2.45 million kilograms of Roundup.

An interesting health issue that has emerged since Bt cotton started being grown in China is a large decrease in the number of deaths of farmers from pesticide poisoning.

7. Bt crops are poisoning monarch butterflies

In 1999, a report published in Nature suggested that monarch butterfly larvae were being poisoned by Bt corn pollen on the surface of milkweed leaves, the major food source for the developing larvae, and commonly found around corn fields. Amid the furore that resulted, a comprehensive collaborative study was performed to examine the issue.

The original study measured the toxicological response of the larvae to the Bt pollen under laboratory conditions, but did not look at it in the field. The subsequent studies showed that while the Bt pollen was toxic to the larvae, the chances of them coming into contact with it on milkweed leaves around the cornfields was virtually non-existent, as the larval phase of the monarch butterfly did not coincide with the corn pollination event. In addition, Bt corn pollen was not widely spread outside the cornfields.

8. GM maize has contaminated Mexican wild maize

Another big controversy in the GM arena is the contamination of native Mexican maize varieties with transgenes from GM maize, despite a ban on GM maize in Mexico since 1998. A study published in Nature last year was highly criticised by scientists, forcing the journal to partially retract its support for the paper in April this year.

The original study made claims that the transgenic constructs had not only introgressed into traditional maize varieties, but also reassorted and inserted in a "diversity of genomic contexts". Critics of the paper said that not only was the paper riddled with technical errors, but that the reassortment and random insertion of the transgenic DNA was unprecedented.

Since the original paper was published, other studies have confirmed that transgenic DNA has been found in Mexican maize crops, but not in wild maize varieties. The jury is still out on the implications.

9. GMOs can be segregated without contamination

Farmer Julie Newman believes that while GM crops can be controlled, they cannot be segregated entirely, and this is a problem. Volunteers (seeds from last year's crop that sprout the following year) and seeds that have escaped from trucks and other transports to contaminate roadside verges are the major forms of contamination.

At stake is the issue of identity preservation. Some of Australia's export markets are looking at zero tolerance of GMO contamination of crops, and this is of big concern to farmers. But who should be segregating their crops, the GM farmer or the non-GM farmer? "If we could grow GM crops and not have to segregate them, it would be wonderful," Newman says.

She says one of the problems is determining who is legally liable for contamination - the non-GM farmer, the GM farmer or the company that produces the GM crop seed. She would like to see protection for both the non-GM and the GM farmers. Otherwise, she believes all farmers will be forced to become GM farmers.

Newman also worries that while percentages of GM contamination are currently almost undetectable, gradually the percentage of the crop that is contaminated with the GM strain will increase. A recent study completed by Australian scientists at the CRC for Australian Weed Management on gene flow from non-GM herbicide resistant canola into non-resistant canola crops indicated that resistance was transferred to plants as much as 3km away from the source.

However, the highest proportion of resistant plants from a non-GM field was less than 0.1 per cent, far lower than the proposed 1 per cent tolerance limits.

Kinnear believes that while it may be feasible to segregate GM crops, it is unlikely to happen unless legislation forces farmers to comply.

10. GMOs cause allergies

A health issue that has raised its head in the GMO debate is whether the transgenes in GMOs could cause allergies. Starlink corn was originally approved only for use in animal feed, as regulatory authorities were not convinced that the transgenic protein was not allergenic. When contamination of corn destined for human consumption with Starlink occurred, the allergy issue ignited.

Subsequently, there has been no evidence that Starlink corn can cause allergenic reactions. Both the Centre for Disease Control and the Food and Drug Administration in the US have performed studies looking at the issue and neither have shown any evidence of allergy to Starlink corn.

The real issue, however, is that not enough allergenicity testing is performed on GM foods. US agriscience think-tank The Pew Initiative on Food and Biotechnology recently released a report on food allergy research for GM foods, concluding that not enough is done to look at this aspect of safety. The report indicates that the possibility of creating unknown allergens should be considered as well as transgenics involving genes from sources known to contain allergens.

11. GMOs create superweeds

A big issue for the use of herbicide resistant GM varieties is the possibility of 'superweeds' appearing with broad resistance to multiple herbicides. But it is still unclear how much this will be a problem unique to GM crops, as resistance occurs anyway with non-GM crops, often within a relatively short time frame.

At the heart of the matter is the possibility of gene flow, or the movement of the resistance genes from the herbicide tolerant plant to other plants. This is not an issue unique to GM plants, it is seen in conventional crops as well and depends very much on the specific crop, how it pollinates and whether closely related plants are found in the same vicinity.

"There is resistance in the normal gene pool anyway," says Clarke. Conventionally bred herbicide tolerant crops are already used in Australia.

Newman says, "There is not much of a chance of crossing a canola with a radish but what you do get is the canola interbreeding with other varieties that are resistant to different chemicals and producing a canola that is resistant to a range of chemicals and hence becoming difficult to kill. It is considered a weed but the better term would be an unwanted, difficult to kill volunteer."

Methods of combating this problem include alternating one kind of GM crop, such as herbicide resistant canola, with a non-GM crop like wheat. Other measures include keeping part of the crop non-GM and restricting the amount of GM seed that can be planted in any one year, a method used with GM cotton in Australia. "Careful management is required," says Kinnear.