ngin - Norfolk Genetic Information Network

5 July 2002



"Our feeling is there is a really dangerous double standard emerging around how science is judged in this field. No studies are perfect but it's deeply worrying that such efforts are going into discrediting critical science where the same efforts aren't going into looking at the safety testing." - Dr Sue Mayer, GeneWatch UK

She said if the same rigour was applied to the environmental and health risk studies submitted to regulators by companies "a lot of things that have been approved wouldn't have been."
Mexican Maize Madness
Anna Salleh, ABC Science Online, 4 July 2002
Part 1 - The War on Words

In April this year, Nature took the unusual step of retracting a paper it had published four months earlier which claimed that transgenic DNA had been found in wild Mexican maize. Since then the case has become the centre of a global war of words between those for and those against GM crops. The lab's Anna Salleh asks what really happened, and looks at what such controversies mean for the future of science.

Part 1 - The War on Words

Tainted Corn: November 2001

On November 29th 2001 the prestigious scientific journal, Nature, published research which reported finding transgenic DNA in maize grown in Oaxaca, Mexico, the centre of origin and diversity for the staple crop.

The paper by, Ignacio Chapela and David Quist of the Department of Environmental Science at the University of California, Berkeley, was a  rallying call for environmentalists.

Greenpeace dubbed it "a worse cultural attack than tearing down Oaxaca's cathedral to build a McDonalds" and demanded an immediate moratorium on transgenic trade. Since Mexico had a moratorium on growing GM crops, US food and feed maize imports were the suspected source of the rogue transgenes.

"Gene-altered DNA may be 'polluting' corn" screamed USA Today. "Remote Mexican crops 'tainted by GM corn'" said the London Daily Telegraph.

The pro-GM scientists network, AgBioWorld Foundation, swung into action. Nature received a number of letters attacking the Quist and Chapela paper. Among the critics were Matthew Metz and Nick Kaplinksy, former and current graduate students of the Plant and Microbial Biology department at the same university as the authors. In 1998 this department signed a five-year $25 million contract with biotechnology company Novartis (now called Syngenta). At the time Chapela testified at a government hearing against the deal. Metz, on the other hand, wrote to Nature in defence of it and today describes Quist and Chapela as "fervent anti-genetic engineering activists" and their work a "testament to technical incompetence".

"No evidence"

In February this year, the journal Transgenic Research published a scathing editorial on Quist & Chapela's research, concluding "no evidence is presented to justify any of the conclusions presented in the paper". The same month, the anti-GM group Food First publicised a statement in support of the researchers. It claimed that like Arpad Pusztai, whose GM potato study triggered the great GM food debate in the UK before them, Quist and Chapela were respectable scientists under global attack because their findings had negative policy ramifications for the biotech industry. It called on academia and private industry to "renounce immediately the use of intimidatory tactics to silence potentially 'dissident' scientists... and to censor those academics that slander the competence or integrity of those who publish peer-reviewed studies."

The statement angered AgBioWorld members who claimed in their 3,700-strong AgBioView email list that Quist and Chapela's paper was "junkscience that shouldn't have made it past a rudimentary peer review process" and said Chapela should lose his job if he didn't release his samples for double checking. According to AgBioView, Quist and Chapela along with Pusztai were anti-GM activists doing bad science to support their preconceptions.

"What is suffering is the reputation of science as being value free," said leading Fellow of the Royal Society, Anthony Trewavas.

On 24 February, a public statement signed by 100 scientists, including Australian scientists Rick Roush and David Tribe, was issued by AgBioWorld. It defended what the Food First statement called "mudslinging" and "unethical attacks" as "simply good, vigorous scientific discourse". Such "relentless criticism and re-examination" was most important when it conflicted with "a point of view driven by politics or activism, rather than science", the statement said. It emphasised that "the kind of gene flow alleged by Quist and Chapela was "inevitable", given the Nature of maize, and "welcome" since it might offer farmers a greater range of traits to select from.

Nature retracts - April 2002

On April 4, Nature published online two scientific critiques of Quist and Chapela (lead authors: Metz and Kaplinsky), a rebuttal from the authors (which included more data to back up their claim regarding gene flow), and a carefully worded editorial which read:

"The authors have now obtained some additional data, but there is disagreement between them and a referee as to whether these results significantly bolster their argument," the editorial read. "In light of these discussions and the diverse advice received, Nature has concluded that the evidence available is not sufficient to justify the publication of the original paper."

However as Quist and Chapela "wished to stand by the available evidence for their conclusions," Nature decided to republish the original article along with the critiques asking readers to "judge the science for themselves"

Nature's actions appears to have made much bigger news than the publication of the original article. Some say Nature should not have given Quist and Chapela so much rope to prove their case, while others protest the role of character assassinations by industry PR hacks lurking in cyberspace. Still others suggest picking at technical nits has deflected attention away from the real issue of "genetic pollution" - a deliberate strategy by the GM lobby to wipe out competition from GM-free crops. By retracting the paper, Nature is now seen as part of this sinister plot.

Nature's editor, Philip Campbell denies his hand was forced. He said recently in a letter to The Guardian that the retraction was because of "technical flaws in the paper that came to our attention after its publication (which we should have picked up), and by the author's decision not to retract the paper themselves."

Due process or double standard?

Disagreement between scientists is the stuff of science but it is expected to be based on legitimate scientific practice, as judged by peer review.

However, as Donald Kennedy Chief Editor of Science admits, sometimes peer review doesn't necessarily get it right, and Nature "deserves credit" for being so open about its processes - although many complain Nature has not been open enough.

According to Kennedy intense scrutiny of a controversial paper can be expected both before and after publication. Certainly Chapela says pre-publication review of the paper was "unusually strict".

Many papers are found to have errors in them after publication so what line did Quist and Chapela cross to warrant Nature's public condemnation? Campbell would not be drawn on the details of this however insists the journal's turnaround had nothing to do with the fact that the paper was about genetic modification.

"It must have been Murphy's law that ensured that our technical oversight, embarrassing in itself, was in relation to a paper about one of the most hotly debated technologies of our time," he said in his letter to The Guardian.

But Paul Gepts, of UC Davis who studies the impact of gene flow between domesticated and wild common bean in Mexico says the rules do seem to be different for hot issues like this.

"I think it is a very controversial area right now and there is almost no middle ground when it comes to transgenic crops," he said. "[Quist and Chapela] have seen a very acrimonious reaction, more acrimonious than for other papers that should not have been published"

Nick Kaplinsky, who wrote to Nature criticising Quist and Chapela, suggests the bar for good science should be set much higher for something with such broad-reaching policy implications - less it be a case of "the boy who cried wolf".

"Some day there is going to be a GMO organism that's going to have adverse effects and there's going to be some science done that points it out," he says. "And if you've had enough false warnings how is the public - and more importantly how are policy makers - supposed to make up their mind?"

"So it's incredibly important for a science that affects public policy to be done well."

However Sue Mayer of the UK watchdog GeneWatch says when it comes to GM risk the high standard is not being fairly applied.

"Our feeling is there is a really dangerous double standard emerging around how science is judged in this field," she says. "No studies are perfect but it's deeply worrying that such efforts are going into discrediting critical science where the same efforts aren't going into looking at the safety testing."

She said if the same rigour was applied to the environmental and health risk studies submitted to regulators by companies "a lot of things that have been approved wouldn't have been."

A lack of research: the plot thickens

Many believe that such fuss over GM crops is a storm in a tea-cup and say that despite five years of widespread GM crop planting, there is no evidence of negative environmental or health effects. However, others say that five years is not a long time when you consider it took decades to discover the impact of chemicals like DDT on the environment.

According to LaReesa Wolfenbarger of the University of Nebraska, who has advised the US EPA, there is in general very little peer-reviewed literature on the ecological risks and benefits of transgenic crops.

She says key experiments which look at the complex interactions of GM crops with other living organisms in the field are missing, as are other studies which compare transgenic practices with conventional and other agricultural practices such as organic farming.

Such studies are necessary in order to weigh up the relative risks and benefits of GM crops compared to other options for moving forward. But there are factors working against the collection of this much needed data.

According to Paul Gepts only one per cent of the US Department of Agriculture's biotechnology program is committed to such studies. The dearth of funding means much research is done using corporate funding and this often brings with it problems of transparency and trust. The reach of commercial influence can extend so far that finding independent referees for peer review itself can be difficult.

Another problem is that assessing environmental health risk often depends on monitoring a technology in the field, by which stage the resources committed to it mean negative results are far less welcome.

Perhaps controversies such as the one over the Mexican maize research are a symptom of a deeper malaise, as the case of the Monarch butterfly controversy suggests.

Given the scarcity of independent scientific research on GMO risks, it is not surprising that groups concerned about unforseen consequences may be tempted to seize upon any studies they can to support their concerns - regardless of its status.

When the first paper to suggest Monarch butterflies could be harmed by Bt corn was published in Nature in 1999, it was also recruited as evidence for environmental concerns - despite the fact it was only a laboratory study and could not say much about what might happen in the field.

However the public controversy prompted more detailed investigations on risk, which were subsequently published in the Proceedings of the National Academy of Science (PNAS). These studies found that the only variety of Bt corn that proved problematic for Monarchs was a variety that was being phased out for other reasons anyway.

The PNAS studies satisfied many that the concerns about Bt corn were unwarranted and that in fact such crops actually benefited butterflies due to reduced insecticide use.

Not all scientists agree. The Union of Concerned Scientists, for example say the effect of Bt corn on Monarchs remains uncertain and point to specific studies that remain to be done.

Others believe there was no basis for concern in the first place - pointing out we've been playing with genes for a lot longer than chemicals and haven't created havoc yet.

As critical as he might be of Quist and Chapela's research, however, Nick Kaplinsky said he would have expected such studies to be been done prior to the release of Bt corn.

"I assumed that the companies that had put Bt corn out there would have said 'Oh, we've done those studies and here's our data which clearly shows that in the real world this isn't a hazard'. And what was really an eye opener for me was that those kinds of ecological studies haven't been done."

Some may lament that debates like this are damaging public confidence in science as a tool for policy making, but perhaps they a linked to a demand for more accountable risk assessment and management policy. Certainly, the controversy over the initial Monarch butterfly study was the trigger for research which many feel was long overdue.

Mexican stand-off or a way forward?

The Nature retraction has sparked an international controversy which calls for an examination of the role of science, politics and money in the debate over genetically modified food crops.

At stake are billions of dollars, public trust in science, and a technology that could feed the world - or cause untold health, environmental and cultural damage - depending on your point of view. Given the lack of independent research, the passion of the principal protagonists and the issues at stake, what is the best way forward?

Many advocate a more proactive, open, transparent and participatory approach to dealing with GM and other technological risks.

The Union of Concerned Scientists calls for a new approach to funding risk assessment research in which the agenda is formulated and overseen by stakeholders to ensure more independent conduct, interpretation and publication of data.

Biosafety expert Anne Kapucinsky from the University of Minnesota is promoting what she's calling the "Safety First Initiative" in which independent safety advocates, under the guidance of a multi-stakeholder steering committee, would veto the release of GMOs if certain safety criteria weren't met.

Such initiatives promises to provide a more socially acceptable way forward under an otherwise intractable climate of uncertainty over the relative risk and benefit of new technologies. But their success, however, will depend on the degree to which the public is made an equal partner in decisions weighing risk and benefit.

While independent reliable scientific studies are essential to help pin down what we know and what we don't know, the very questions asked, or not asked, can be a very political issue. And judgments such as whether the evidence available warrants proceeding down one track or another are also value laden. No amount of "sound science" will ultimately settle such debates as they belong well and truly in the realm of politics

There are many reasons why people may not want rogue transgenes in their crops. Apart from concern over unforseen health and environmental risks, they may want to trade GM-free produce as some farmers in Australia want to, or they may want to protect a cultural icon, as maize is in Mexico. They may believe there are more sustainable alternatives to GM crops. Such factors can not be separated from arguments of GMO risk as they are values that influence responses to uncertainties raised by the new technology.

Rather than dismissing such broader concerns as anti-technology, anti-progress or risk-averse, those who make decisions on risk need to engage rationally with them. Until a more inclusive science-based policy making arises, a polarised debate will continue. Both sides will do their best to attack each other's credibility and maintain moral superiority. And every skerrick of scientific evidence of GM risk - no matter what its status - runs the risk of becoming the eye of a storm of rhetoric which achieves little more than an ongoing Mexican stand off.

ngin bulletin archive