Today in AgBioView from http://www.agbioworld.org - August 30, 2006
* Rice Breakthrough Promises Secure Future Supplies
* Spilling the Beans?
* Mexican Maize Planting - Correction
* UK Growers Support GM Potato Trials
* Next: Attack of the Killer Tomatoes?
* Africa: Scientists, Environmentalists Want Vitamin A Rice
* What Inspired You to Take Up Science?
* Who Is Science Writing For?
* Anti-GM gloaters
* Crops May Produce Herbicide Inside Our Intestines or Do They?
Rice Breakthrough Promises Secure Future Supplies
- Anthony Fletcher. Food Navigator, August 29, 2006 http://www.foodnavigator.com/
A major global scientific effort to enhance the efficiency of rice could have important implications in the supply of the world's most important food. Experts are working on converting rice from being a C3 plant to a C4 plant, where the 'C' refers to the carbon captured by photosynthesis for growth.
The more solar energy a rice plant can efficiently capture, the more it will yield. "We need to meet the challenge of feeding a growing world population which is projected to reach 8.3 billion in 2030 with an accompanying rice demand of 771 million tonnes," said the International Rice Commission secretary Nguu Nguyen.
In order to meet this expected demand for rice in 2030, Nguyen said that global rice production 618 million tonnes in 2005 would need to increase by about 153 million tonnes. "This is an enormous challenge as land and water resources available for rice production keep diminishing as a result of urbanisation and industrialisation," he said.
Rice is the primary food for more than three billion people around the world. Approximately one-fourth of the global rice crop is grown in rain-fed lowland plots that are prone to seasonal flooding. These seasonal flash floods are extremely unpredictable and may occur at any growth stage of the rice crop.
But Nguyen said that C4 rice could have the potential to out-yield the best performing existing rice varieties and hybrids by 15 to 20 per cent. However, it will take several more years before the C4 rice varieties may become available. "And, then we will have to make sure that they are safe for human and animal consumption as well as for the environment," he said.
The future of rice production therefore looks positive. The major historic breakthrough that has allowed scientists to propose such solutions as C4 was the successful mapping of the rice genome in 2002, which created new opportunities for the application of genetic resources for breeding new generation of rice varieties.
However, concerns related to bio-safety, conservation of rice genetic diversity and intellectual property rights remain. These will have to be dealt with before C4 rice becomes a reality.
Spilling the Beans?
- Dr. Christopher Preston, University of Adelaide, Australia; christopher.preston(at)adelaide.edu.au; AgBioView from http://www.agbioworld.org - August 30, 2006
The publication of Jeffrey Smith's new book, Genetic Roulette, is only days away. To prepare us we have another excerpt from the book published in "Spilling the Beans" (http://www.seedsofdeception.com/utility/showArticle/?objectID=678). In this months episode, we hear about the trials and tribulations of Kirk Azevedo. As Smith tells it Kirk was a young and impressionable man who went to work for Monsanto in 1996. In true good versus evil manner, young Kirk becomes disillusioned with Big Bad Monsanto's ignorance, culpability and evil commercial ways, refuses to participate in such practices and leaves in 1998 to become a chiropractor.
On reading the story by Smith, I can't escape the feeling that the story has become embellished with the telling. In particular, Smith writes the following:
"In the summer of 1997, Kirk spoke with a Monsanto scientist who was doing some tests on Roundup Ready cotton. Using a "Western blot" analysis, the scientist was able to identify different proteins by their molecular weight. He told Kirk that the GM cotton not only contained the intended protein produced by the Roundup Ready gene, but also extra proteins that were not normally produced in the plant. These unknown proteins had been created during the gene insertion process.
Gene insertion was done using a gene gun (particle bombardment). Kirk, who has an undergraduate degree in biochemistry, understood this to be "a kind of barbaric and messy method of genetic engineering, where you use a gun-like apparatus to bombard the plant tissue with genes that are wrapped around tiny gold particles." He knew that particle bombardment can cause unpredictable changes and mutations in the DNA, which might result in new types of proteins."
A major problem with this story is that Roundup Ready cotton was not produced by bolistics, but by Agrobacterium transformation (http://www.monsanto.com/monsanto/content/sci_tech/prod_safety/roundup_cotton/pss.pdf, http://www.monsanto.com.au/content/cotton/rr_cotton/fsanz.pdf, http://www.aphis.usda.gov/brs/aphisdocs2/95_04501p_com.pdf).
Later on, Kirk worries about these unknown proteins being prions and causing diseases like mad cow disease. Unfortunately for this story, there are no human diseases known to originate from prions in plants. Indeed, I can find no discoveries of prions in plants, although they apparently do occur in fungi.
Kirk later complains to Monsanto staff about feeding of test plot material of Roundup Ready cotton to cows. "…Kirk came to find out that Monsanto was feeding the cotton plants used in its test plots to cattle. "I had great issue with this," he said…." The issue Kirk had was that "unknown proteins, including prions, might even effect (sic) humans who consume the cow's milk and meat."
This was apparently in 1997. This might have made a good story, except for the fact that APHIS declared Roundup Ready an unregulated article in July 1995 (http://www.aphis.usda.gov/brs/aphisdocs2/95_04501p_com.pdf), and the FDA provided food and feed approval in September 1995 (http://www.cfsan.fda.gov/~rdb/bnfm026.html).
This leaves me to wonder what, if any, kernels of reality are present in the rest of the story.
Correction - From Vivian Moses
On the 26th, I included a report "Crop Biotech Update (25.8.06) - Biotech maize approved for Sonora, Mexico". (which was reproduced in AgBioView....CSP)
It appears that this information is not correct. I am advised that the next step in the process to obtain a commercial approval to plant biotech maize in Mexico is to secure the Permit to conduct the Biotech Maize Master Project. Sonora is one of the States targeted for the Master Project (also Sinaloa and Tamaulipas) but the authority has not granted the Permit. The submissions for the Master Project are under Public Consultation that will end on September 19 and after that date authorities will take time to review comments received and deliver a decision. Authorities have a period of two months that started from August 15.
UK Growers Support GM Potato Trials
- Western Morning News, August 28, 2006 http://www.thisisdevon.co.uk/
Potato growers have given their support to controversial trials which could see a genetically modified variety on West country supermarket shelves within a decade. Although farmers remain cautious about the crops, many feel properly regulated tests will give valuable information on what some see as the inevitable future of the industry.
However, protesters remain firmly opposed, citing the risk of cross-contamination to non-GM crops and the unknown effects on human health.
German biotechnology firm BASF claims it has developed a way to grow the vegetables without the risk of blight - the disease that sparked the devastating Irish potato famine. Once it took hold in 1846 more than one million people are estimated to have died of hunger during the five years before it was eradicated.
Growers say the South West is a high-risk blight area because of the heavy rain levels. BASF is seeking permission from Defra for field trials of the GM variety at sites in Derbyshire and Cambridgeshire in spring.
The crops, which have been trialled in Sweden and Germany, but never in the UK, incorporate a gene from wild potatoes, which are resistant to blight. BASF says the new breed could yield a higher harvest and also cut down the need for spraying fungicides to kill the disease. There are more than 130 potato growers in Devon and Cornwall, producing more than 150,000 tonnes of potatoes each year, including varieties such as Estima, Lady Rosetta and Maris Piper.
Andrew Richards, of Trengrove Farm near Portreath on Cornwall's north coast, said blight was a major problem for farmers. "We are always concerned about it," he said. "If we can find the gene which can help reduce that risk I'd be all for it, as long as it had been properly tested."
Former potato farmer Richard Moynan, now an agronomist who advises growers, said the trials would be a useful tool to find out more. Mr Moynan, based near Exeter, said he believed the future of GM was in building up resistance to disease, rather than increasing nutritional benefits. "If it is used to stop the advance of disease it is a good thing, but beyond that it should be treated with caution," he said.
Ian Johnson, South West spokesman for the National Farmers' Union, said: "The only problem as far as I can see might be from the very small but highly organised organic sector which would quite rightly have concerns about the integrity of their crops." But he said potato spores were less likely to travel than other crops, because they spread underground.
Michael Hart, chairman of the Small and Family Farmers' Alliance, said: "Farmers are always being told to listen to the consumer, and the overwhelming message is that they do not want GM. It would be rather foolish to go into growing it."
Next: Attack of the Killer Tomatoes?
- Fort Worth Star-Telegram, August 28, 2006 http://www.dfw.com/
Hearing about the escape of a biogenetically engineered plant may have struck a chilling chord among some folks when the Star-Telegram published a brief news item earlier this month under the headline "Biotech grass growing in the wild."
In these days of stunning scientific advances in bioengineering, that may well have sounded to some people like "Frankengrass" was invading nature.
Not so, we're told. Mad scientists haven't created a superweed. But critics of agricultural bioengineering will have fresh fodder for their arguments.
The news item came from a New York Timesreport about scientists discovering in central Oregon what may be "the first instance in the United States in which a biotechnology plant has established itself outside a farm."
The plant, creeping bentgrass (which does sound a bit spooky), is being developed by Scotts Miracle-Gro Co. and Monsanto for use on golf courses. Their aim is to offer bentgrass that may not prevent divots but will be resistant to the herbicide glyphosate, known as Roundup, the thought being that golf course workers could spray glyphosate on large areas of fairways and greens without harming the grass.
Therein lies the reason not to worry excessively about the Oregon development, says Keerti S. Rathore, Ph.D., assistant professor in Texas A&M University's college of agriculture and life sciences and an expert in agriculture biotechnology.
He notes that the creeping bentgrass is being bred specifically to resist glyphosate. If that grass spreads to wild relatives, as it may in Oregon, the worst that would happen is that those related grasses would become resistant to Roundup but not other herbicides.
But critics contend that risks remain, ranging from the creation of superweeds to questionable federal controls that are too lax.
Doug Gurian-Sherman, who holds a doctorate in plant pathology for the nonprofit Center for Food Safety and is a former advisor to the U.S. Department of Agriculture, notes that federal guidelines require only a scant 900 feet of separation between a crop such as the bentgrass and grasses growing in the wild.
That's clearly not enough, he said -- the experimental bentgrass in Oregon, one of 170 field trials, was found 2.4 miles away from the test crop. Scientists with the Agriculture Department and the Environmental Protection Agency are evaluating the situation and will report on their assessment soon.
Meanwhile, consumers here and elsewhere in the world continue to benefit from harvests of the dominant bioengineered crops -- corn, cotton and soybeans -- that evidently have posed no serious hazards so far but contribute significantly to the welfare of humanity.
As the USDA notes on its Web site, "Breeders have been evaluating new products developed through agricultural biotechnology for centuries," and an estimated 8.25 million farmers in 17 countries are growing biotech crops.
One errant patch of creeping bentgrass in Oregon isn't likely to uproot that sort of value
Africa: Scientists, Environmentalists Want Vitamin A Rice
- Josephine Maseruka, New Vision, August 30, 2006
Scientists are working round the clock to develop the much needed acceptable rice variety with Vitamin A that can help the 400 million people in the world at risk of vitamin A deficiency.
The first African Rice Congress held in Dar es Salaam early August heard that between 100 and 200 million children are affected by severe vitamin A deficiency of whom 50 million are in Sub-Saharan Africa. Records also show that 1.3 million to 2.5 million pre-school children die annually because of vitamin A deficiency. In developing nations, where Uganda falls, vitamin A deficiency is responsible for 250,000 cases of blindness every year.
Vitamin A deficiency is also a leading cause of early child death, diarrhoea, measles, pneumonia and a major risk factor for pregnant and lactating women. The alarming situation has led to attempts by European scientists to develop rice varieties with vitamin A.
Dr. Ingo Portrykus, a professor of science at the Swiss Federal Institute of Technology and Peter Beyer of the University of Freeburg in Germany have developed the Golden Rice with high levels of Beta-carotene, which is converted to vitamin A in the body. Two genes were taken from a plant called daffodil and a third gene from bacterium which were introduced into rice through genetic engineering to get rice with vitamin A.
Dr. G.S. Khush of California University told the congress that the goal for the genetic engineering was to improve the rice nutritional content to fight the growing rate of malnutrition, especially among people who derive most of their calories from rice.
Khush said the invention was also aimed at lowering the risk degree of vitamin A deficiency and healthy problems that result from it.
The International Rice Research Institute Director P. Anderson said, 'Vitamin A is necessary for the poor. We cannot reach the very many of the malnourished in the world. Rice with vitamin A can be a suitable alternative.'
However, the Golden Rice has already met stiff resistance from scientists and environmentalists. They argue that 300gm of Golden Rice can provide at most 20% of adult's daily dose of vitamin A and since pre-school children consume less than 150gm of rice daily, Golden Rice would only supply a little 10% of the required vitamin A daily.
Others have reasoned that vitamin A can be obtained from liver, milk, butter, egg yolk, chicken, meat while Beta-carotene can be got from dark green vegetables, spinach, carrot, pumpkin and mango, which can be taken in small quantities.
There are already attempts to get vitamin A through orange sweet potatoes, which are affordable to small farmers and the rural poor.
Health experts argue that Golden Rice if taken by people who have rice as a staple food, could lead to excessive intake of vitamin A among those who do not suffer from vitamin A deficiency.
Excessive vitamin A can lead to hypervitaminosis or vitamin A toxicity which leads to abdominal pain, vomiting and dizziness. Daffodil is responsible for allergic reaction that manifests as a rash. (from CSP: this shows the ignorance of critics. Beta carotene is converted into vitamin A in right amounts in our body and beta carotene does not cause toxicity in our food.....Golden rice has beta carotene, the precursor to vitamin A)
Environmentalists insist that they need proof that there are no serious environmental consequences to the ecology from the Golden Rice and that it won't have adverse effect or risk on people's health.
Scientists must ensure that the Golden Rice must be accepted as a miracle for vitamin A deficiency and must not blindly release it with unknown risks of producing vitamin A through genetic engineering.
What Inspired You to Take Up Science?
- Sandy Starr, Sp!ked, August 29, 2006, http://www.spiked-online.com/
What Inspired You? is a survey of key thinkers in science, technology and medicine hailing from all corners of the globe, ranging in age from 19 to 93 and ranging in experience from new talents to Nobel laureates. Each of these individuals was asked: 'What inspired you to take up science?' The survey was conducted by spiked in collaboration with the research-based pharmaceutical company Pfizer, in order to provide insights into current challenges in science education and science communication, and how these challenges might be overcome.
Concerns over the younger generation's seeming indifference to science have prompted various initiatives and proposals, which aim to make science more 'relevant' to children and to the broader public. Programmes of study recently introduced across the UK have asserted a new distinction between 'science for citizens' and 'science for scientists', with a corresponding focus upon 'scientific literacy' - a concept quite different from aptitude in the sciences as it has traditionally been understood. Critics argue that such initiatives can only denude science education and science communication of their scientific content, and therefore fail to convey anything of the the true significance and rigorous methods of science.
It is in the context of these concerns and debates that we asked our diverse range of survey respondents to tell us what inspired them to take up science, and by extension, what might inspire the scientists and thinkers of the future.
Read on at http://www.spiked-online.com/index.php?/inspired/article/1480/
What Inspired You?
- Ingo Potrykus, chair of the Humanitarian Golden Rice Board and Network, emeritus professor of plant sciences at the Swiss Federal Institute of Technology, and creator of Golden Rice
My interest in biology was, from early youth, that of an outdoor biologist with heavy focus on birds. This is still my major hobby, after 60 years.
How did a lifelong ornithologist get sidetracked in such a way that he is now known for his work as 'plant genetic engineer' – everybody 'knows' that these people have no respect for nature – and his Golden Rice? I studied biology, majoring in zoology, but was converted to botany by the personality of Josef Straub, a professor of botany and director of the Max Planck Institute for Plant Breeding Research.
My inspiration to take up science was the phenomenon of totipotency of plant cells, and I spent a considerable part of my career trying to learn more about it. We still have very little idea why and how a leaf cell specialised for photosynthesis manages to develop into a fully functional embryo, if freed from the context of the leaf tissue and provided with a simple mineral culture solution.
But then I was sidetracked again. I was fascinated by the engineering potential provided to us by the totipotency of plant cells. And that's why, circa 1972, I developed into a genetic engineer interested in practical solutions, motivated by the problem of food insecurity of so many millions in developing countries. From then on, until my retirement and beyond, I invested of all my capacity and that of my research team into the development of genetic engineering technology for food security crops such as rice, wheat, sorghum, cassava, and into trying to rescue harvests and improve the nutritional quality of staple crops.
from Alan McHughen http://www.spiked-online.com/index.php?/inspired/article/1387
From Vivian Moses http://www.spiked-online.com/index.php?/inspired/article/1389
from Jonathan Jones http://www.spiked-online.com/index.php?/inspired/article/1371
from Prakash: http://www.spiked-online.com/index.php?/inspired/article/1395
Who Is Science Writing For?
- Margaret Wertheim, Bioscience, August 2006, Vol. 56 No. 8 www.biosciencemag.org (Hat Tip: Sonny Ramaswamy)
We all know the dismal statistics: Our children's test scores on international assessments of math and science literacy are plummeting; the number of PhD students in science and engineering is at a 40-year low; we are desperately short of science teachers; intelligent design is spreading like kudzu; and most of our citizens believe in ESP, angels, or alien abductions. There is much public hand-wringing, and those of us who love science have good reason to worry. The question we face is how to respond. As someone who has been writing about science for the general public for more than 20 years, I would like to suggest that some radical changes are called for in our strategies for communicating science.
The very verb we are dealing with points to the nub of the problem.Unlike speaking and writing,"communicating" supposes an active engagement on the part of an audience. For something to be communicated, it has to be not only transmitted but also received. Yet in discussions about how to improve the public's understanding of science--of which there are an escalating number—it seems that only one side of this channel is addressed. We ask: How can we better transmit the findings of science? As a journalist, I wrestle with this daily and feel thrilled when I have managed to coin an elegant article on the ecology of a termite's gut or the mechanics of a spider's eye.But there is another question that has, I think, been factored too little into our discussions:Who is on the receiving end of our missives? In short: Who are we writing for?
The primary public resources about science are popular science magazines. It is worth asking,Who buys them? Who reads them? The answers surprise many scientists--and many professional science communicators, too.
Eight top-selling science magazines--Scientific American,Discover, Popular Science, Wired,Natural History, Science News, Astronomy, and Science--collectively sell about 4.5 million copies a month. In all, they claim around 17 million readers. In magazine-world parlance, a "reader" is someone who spends at least half an hour with an issue. Reader numbers are quoted to attract advertisers and are notoriously optimistic, but let us give the benefit of the doubt here and say that 17 million Americans are looking at some science magazine each month. Who are they? In a nutshell, they are overwhelmingly well-educated men over 40 in the upper socioeconomic brackets.
I gathered the statistics as an exercise a few years ago when the latest figures available were for 2002, but I very much doubt they have changed significantly in the intervening years. These are the facts: In 2002, the median age of Scientific American subscribers was 49; for readers, it was 46. The median age of Discover readers was 41; of Popular Science readers, 43; and of Science News subscribers, 49. Of Scientific American's subscribers, 87 percent were men and 13 percent were women. Wired's subscribers were 85 percent male, 15 percent female; Science News subscribers were 72 percent male.
A representative at Popular Science, by far the biggest selling, laughed when I asked for a gender breakdown and said I could safely assume the vast majority were men. Of Scientific American's subscribers, 85 percent had college degrees and 58 percent had graduate degrees. For Science News the figures were 78 percent and 46 percent. The median salary of subscribers to Scientific American was $87,600; to Wired, $90,800; and to Natural History, $74,000. Age also provides a window: Two-thirds of the audience of Popular Science and Discover--which together accounted for 2.5 million copies per month--were over 35 years old. For Scientific American and Science News, almost 80 percent of subscribers were over 35. Of all subscribers, 22 percent were women. Most of the magazines did not break down their numbers by race.
According to the Census Bureau, the current US population is 299 million. This means that more than 280 million people are not reading any science magazines. Women, people under 35, and those in the lower socioeconomic brackets are barely being touched by the canonical channels of science communication. Let me introduce, then, another set of numbers. At the same time that I researched statistics on science publications,
I also looked at women's magazines. Again I chose eight top sellers--Vogue, Elle, Glamour, Cosmopolitan, Self, Redbook, In Style, and Good Housekeeping. In 2002, these magazines collectively sold 17.5 million copies a month.Good Housekeeping alone sold more copies than all eight science magazines combined (at 4.7 million a month), and none of the eight sold less than a million.With sales this huge, the women's magazine world does not always bother to collect reader statistics, but if we assume the number of readers per copy is similar to that claimed by the science publications, then close to 70 million people are reading a women's magazine each month.
It is perhaps a sad fact, but ineluctably a true one, that most women do not go near science magazines. It seems to me that if we are serious about improving the public understanding of science,we have to start looking at where the public is-- and if the mountain is not coming to us, then we must go to it. It is for this reason that for many years, in my native Australia, I wrote columns about science for women's magazines such as Vogue and Elle. I considered this my missionary work.
Writing for the hairdo and hemlines set carries no cachet in the science world--and little in the science communication world, either--but I consider this some of the most difficult (and serious) work I have done. Believe me, it is harder to explain genetic engineering or big bang cosmology in the context of Vogue than in the infinitely more prestigious pages of the New York Times's Science section, for which I also write. The most difficult work I have done by a long shot was writing a television science series aimed at teenage girls, made for ABC Australia.
In May I was presented with the Print Media Award by AIBS for a pair of articles I wrote for the LA Weekly, sister paper to the Village Voice.As the flagship of alternative newspapers, the LA Weekly is known for its arts, culture, and political coverage; before me, they had never had a science writer, and it took me five years to convince them to let me do a science column. It has been an honor and a pleasure and also a challenge. I have to assume my readers know nothing whatever about science and that even the most basic concepts must somehow be conveyed without seeming teacherly. I have had the support of a wonderful editor, Tom Christie, who goes through my pieces with a fine-toothed comb, an open mind, and a naïf's questions. I am sometimes staggered at the things Tom doesn't know, but I remind myself that if he doesn't know, then 99 percent of our readers won't, either.Yet ours is an educated and literate audience.
Scientists often think that science writers dumb down their work, skimping on details and eliding over subtle distinctions.
But most science writers--myself included--also love to write long pieces that convey the intricacies of a subject. It is these stories that meet with the approval of scientists (whose approval we journalists naturally desire) and that generally win awards.But the stark reality of our dollar-driven age is that print space is a precious commodity, and we are increasingly lucky to have any column inches for science. It is frustrating to have only 900 words, as I did for my columns in the Australian Vogue, or 1200, as I do now in the LA Weekly, to describe something as complicated as bioremediation or the physics of freezing; but 900 words are better than no words, and in the context of improving the public's understanding of science, every one of them is precious.
Scientists, by training, are experts; the public, by default, are not--and the gap between these two domains is getting wider. It will not do to sit around and bemoan this fact and hope that one morning we will wake up and find that everyone is reading Science, or even Popular Science. They will not.
We may not like the creationists, but there is one thing we could learn from them: the power and the value of grassroots proselytizing. In short, those of us who love science are called upon to be missionaries. It is time to get off our high horses and go out to the people.
Margaret Wertheim is director of the Institute For Figuring (www.theiff.org), a nonprofit organization she founded to pursue new ways of communicating about science and mathematics.
- August 28, 2006. Links at
It never fails to amaze me how much the anti-Genetic Modification (GM) crowd love to gloat at any problems (real or perceived) with GM crops. Reader Paul sent me a link to this Science Blogs Effect Measure article claiming GM cotton resistant to bollworm planted in China, is proving to be "a curse", since other pests have grown stronger:
> Genetically modified cotton resistant to bollworm is a reality and five million Chinese cotton farmers have embraced it. It works, too, killing bollworm larvae that used to kill their cotton. IN the late 1990s it looked like a miracle. Pesticide use was cut by 70%. After seven years, though, the miracle is looking more like a curse because new pests called mirids have rushed into the pest vacuum and taken up shop.
The writer quotes from this New Scientist article.
So, this must be a reason to ban all GM crops, right? That's the obvious conclusion: any problem - ban it all. (It's what Greenpeace wants.) Well, first perhaps we should look a little closer at what is actually happening.
> From China Economic Net (all quotes with my bold): CCAP director Huang Jikun said the Cornell team's conclusions could be based on an incorrect reading of the data. According to Huang, 2004 had particularly low summer temperatures and more precipitation, so the mirids affected not only cotton but also other conventional crops nearby. CCAP interviews with the same farmers in 2005 and 2006 showed fewer mirids.
So perhaps things weren't quite the "curse" they seemed? Still, I agree the growth of a different pest is a concern. So ban them then. End the experiment! Yes? Or perhaps a more scientific idea would be to manage them better. From CheckBiotech.org
> Zhang Yongjun, a senior research fellow at the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences, said the rise of the secondary insect problem was mainly due to the poor management of GM cotton growth in China.
> Before planting anti-insect cotton, Chinese farmers widely used broad-spectrum pesticides, which killed both bollworms and mirids. But using the pesticides increased costs, caused pollution and harmed farmers' health. After planting anti-insect cotton, however, farmers use pesticides only in the final stage of the crop's growth, when the Bt cotton's resistance against bollworms is relatively reduced. "But in terms of preventing mirids, it's too late," said Zhang.
> That situation, coupled with weather factors, eventually led to the outbreak of mirids across cotton-growing provinces in 2004, Zhang explained. If the proper pesticide had been used at the right time, the mirids could have been controlled in 2004, he said.
> And from Cornell University: When U.S. farmers plant Bt crops, they, unlike farmers in China, are required by contracts with seed producers to plant a refuge, a field of non-Bt crops, to maintain a bollworm population nearby to help prevent the pest from developing resistance to the Bt cotton. The pesticides used in these refuge fields help control secondary pest populations on the nearby Bt cotton fields.
GM crops are not perfect, but then no solution is without costs. For example, before GM cotton was introduced, 400 to 500 Chinese cotton farmers used to die every year from pesticide poisoning. Ban GMOs and you have to consider these costs (and others) that would increase. A better solution would seem to be learn from these developing problems and manage them better. As the Cornell article puts it:
"Research is urgently needed to develop and test solutions."
These include introducing natural predators to kill the secondary pests, developing Bt cotton that resists the secondary pests or enforcing the planting of refuge areas where broad-spectrum pesticides are used.
Of course science doesn't always get it 100% right first time but that doesn't mean you abandon a project at the first sign of a problem. And that's especially true when there are potentially huge benefits to be gained. I realize Greenpeace and the like aren't interested in scientific explanations and solutions, but I wouldn't expect a real scientist to dismiss a whole field of science just because something didn't work out perfectly first time. Which is why I am surprised and disappointed this supposed "Science Blogger" ends his article with the tart:
Maybe this is why the tag line of Pete Seeger's anti-war song, "Where have all the Flowers gone?" is "When will they ever learn?"
When will they ever learn? They? If he's referring to the anti-GM gloaters, it seems only after "a long time passing". When will they ever learn indeed.
Genetically Engineered Crops May Produce Herbicide Inside Our Intestines or Do They?
- Dr. Christopher Preston, University of Adelaide, Australia; christopher.preston(at)adelaide.edu.au; AgBioView from http://www.agbioworld.org - August 30, 2006
A story is doing the rounds at the moment by Jeffrey Smith claiming a previously unidentified danger from LibertyLink crops. According to Smith, the problem lies in a metabolite of the herbicide glufosinate that can be converted back to glufosinate and cause all sorts of problems. You can read the whole story if you like at: (http://www.responsibletechnology.org/utility/showArticle/?objectID=505).
Briefly Smith's thesis is that glufosinate in LibertyLink plants is converted into an inactive compound. On ingestion this compound converts back into glufosinate in the gut. Because glufosinate is a highly toxic compound causing all sorts of physiological and psychological problems, this poses a 'unique risk".
This story turns out to be a fascinating example how a few kernels of truth can be dressed up into a royal banquet. If we look below the façade of the feast, this is what we see.
LibertyLink crops are tolerant to glufosinate because they have been transformed with an enzyme that acetylates glufosinate. The product produced N-acetylglufosinate (NAG) has no herbicidal activity. NAG is not the only product produced, there are several others generally characterized as methylphosphinyl fatty acids (MPFs) including 3-
methylphosphinicopropionic acid (MPP). However, in LibertyLink plants, the main metabolite is NAG. NAG is relatively stable in plants and is present at harvest (Ruhland, M., Englehardt, G. and Pawlizki, K. 2004 Distribution and metabolism of D/L-, L- and D-glufosinate in transgenic, glufosinate tolerant crops of maize (Zea mays L ssp mays) and oilseed rape (Brassica napus L var napus) Pesticide Biochemistry and Physiology 60: 691-696, OECD 2002 Module II: Herbicide Biochemistry, Herbicide Metabolism and the Residues in Glufosinate-Ammonium (Phosphinothricin)-Tolerant Transgenic Plants. OECD Environment, Health and Safety Publications, Series on Harmonization of Regulatory Oversight in Biotechnology, No. 25).
For NAG to appear in the diet it needs to be present in the material that is eaten. Glufosinate is normally applied post-emergent to young weeds. For agronomic crops, this will be an application early in the season several months before harvest. Most of the glufosinate applied is washed off the plants during the course of the growing season (Ruhland et al. 2004). The glufosinate that is absorbed by the plants and its metabolites are mainly found in the treated leaves (92% in maize and 64% in canola) with other vegetative parts of the plant containing most of the rest (7% in maize and 31% in canola). In maize, less than 0.1% of glufosinate and its metabolites are present in the grain (0.06 mg/kg) and for canola less than 0.15% or 0.1 mg/kg is found in grain (Ruhland et al. 2004).
There is a wealth of other publicly available information on glufosinate residues. Some of this information is summarised in OECD (2002). This summary stated that residues in seed of glufosinate canola treated with between 700 g/ha to 2 applications of 800 g/ha of glufosinate and its metabolites ranged from < 0.05 mg/kg to 0.24 mg/kg. Residues in oil were not detected.
For glufosinate resistant maize, application rates of 400 + 500 g/ha or 2 applications of 800 g/ha produced residues of glufosinate and its metabolites in grain ranged between < 0.05 mg/kg to 0.07 mg/kg. Glufosinate and its metabolites were not identified in corn oil.
For glufosinate resistant soybeans, application rates of 400 + 500 g/ha produced residues in grain between 0.32 and 1.88 mg/kg.
For glufosinate resistant sugar beets, 2 application of 600 or 800 mg/kg resulted in residues of glufosinate and its metabolites in roots ranged between < 0.05 mg/kg to 0.88 mg/kg. Glufosinate and its metabolites were not identified in refined sugar.
The FAO evaluation of glufosinate (http://www.fao.org/WAICENT/FAOINFO/AGRICULT/AGP/AGPP/Pesticid/JMPR/Download/98_eva/glufosi.pdf) lists a large number of studies. Glufosinate and its metabolites were not detected in grain from transgenic maize treated with glyphosate across at least 57 trials in 4 countries of Europe (there are more trials listed, which are probably on transgenic corn, but not unambiguously identified as such). The same was true for 2 trials from Argentina. In the US, there were 71 trials listed. Glufosinate and its metabolites were not detected in grain from transgenic maize treated with glyphosate in 70 of these trials. One trial reported levels of 0.26 mg/kg for glufosinate + NAG and 0.06 mg/kg for other metabolites. In Canada, 22 trials on transgenic maize are reported with glufosinate not being detected in grain in any of the trials. NAG was detected in grain in 3 trials at levels of 0.07, 0.08 and 0.09 mg/kg.
For soybeans, 34 trials in the US are reported. Residues of glufosinate and/or its metabolites were detected in all trials ranging between <0.05 mg/kg up to 7.6 mg/kg for NAG in some early trials where glufosinate was applied late and at high rates.
For canola, glufosinate and or its metabolites were found in 18 of 26 trials in Europe at concentrations up to 0.15 mg/kg. From 50 trials in Canada, glufosinate residues were found once at 0.12 mg/kg. NAG metabolites were detected in 13 trials at concentrations up to 0.24 mg/kg. Other metabolites were not detected. From 8 trials conducted in Australia, glufosinate and its metabolites were not detected in grain.
For sugarbeet, glufosinate or its metabolites were detected in all of 9 trials in Europe at concentrations ranging from 0.05 to 0.99 mg/kg. In North America, glufosinate was detected in roots in all of 31 trials at concentrations ranging from 0.05 to 0.93 mg/kg.
This evaluation also reports on the fate of glufosinate during food processing. For sugar from beets, the residues tended to stay in the molasses and were not detected in raw sugar. In 4 different trials, the amount of glufosinate + NAG in the molasses ranged from 0.69 to 3.8 mg/kg.
For soybeans and canola processed for oil, glufosinate and its metabolites were not detected in the oil.
For processed products: soybean oil, canola oil and sugar, no glufosinate or metabolites were detected. Therefore, the only way you could consume any NAG would be to eat corn or molasses made from transgenic plants. I could find no data on glufosinate residues in tofu, but that might be another possibility.
The no observable adverse effect limit (NOAEL) for glufosinate is 2 mg/kg body weight. The NOAEL is the highest concentration that in long term feeding studies produces no observable effect. The acceptable daily intake (ADI) for glufosinate and all its metabolites, including NAG, is set at 0.02 mg/kg body weight. This is a 100-fold safety factor (http://www.inchem.org/documents/jmpr/jmpmono/v99pr06.htm). For a 70 kg person to reach the ADI you would need to consume at least 5.4 kg of corn per day (using the highest residue of glufosinate + NAG reported for corn). That's 120 tortillas a day. Alternatively, you could choose to consume 370 g of molasses a day, although you might not stay at 70 kg if you did so.
To summarise, transgenic glufosinate resistant plants do convert glufosinate into NAG; however, very little if any NAG ends up in the grain and none in processed foods. The chances of consuming any significant amount of NAG are very low.
The second step in Smith's thesis is that NAG will be converted back into glufosinate in the gut and this presents a danger.
Feeding studies on NAG have been performed and are reported in the toxicological evaluation of glufosinate by FAO and WHO (http://www.inchem.org/documents/jmpr/jmpmono/v99pr06.htm). When NAG was fed to rats, small quantities of glufosinate were afterwards detected in faeces. These amounted to 11% of the total NAG fed at 3 mg/kg body weight and 0.9% of the total NAG fed at 1000 mg/kg body weight. A second experiment that fed rats 30 mg/kg NAG found 5% of the administered NAG in faeces and 0.02% in urine. A third experiment that fed rats 3 mg/kg NAG intravenously found most of the material remained as NAG.
These experiments demonstrate that NAG can be converted back into glufosinate in the gut. There are bacteria in the gut that both acetylate glufosinate and de-acetylate NAG. However, the conversion is fairly poor. What Smith is not telling us is that the vast majority of the NAG fed to the rats passed through as faeces. This percentage ranged from 83 to 89% of the radioactivity. This indicates that NAG is poorly absorbed on its passage through the intestinal tract.
These experiments also demonstrated that NAG passes quickly through the intestinal tract. More than half the NAG and its metabolites had been excreted within 24h and over 80% within 48h for rats fed a high dose of 1000 mg/kg. Rats fed a low dose of 3 mg/kg excreted more than 90% of the NAG within 24 h. It is important to note that these doses are many times higher than could be consumed by humans eating products from GM crops.
Smith mentions an example of an experiment with a lactating goat fed radioactive NAG where a third of the radioactivity in the faeces was glufosinate. Again, what Smith fails to mention is that the vast majority of the radioactivity, whether NAG or glufosinate, was excreted in the faeces. Of course, goats being ruminants may have more bacterial able to de-acetylate glufosinate in their intestinal tract than do non-ruminants.
To summarise, small amounts of NAG can be converted to glufosinate in the gut. However, NAG passes through the system so fast that consumption of NAG is unlikely to result in any significant accumulation of glufosinate. It seems that most glufosinate that does get produced in the gut is excreted in faeces. The ADI and maximum residue limits (MRL) for glufosinate include glufosinate and its metabolites NAG and MPP either alone or in combination. Therefore, it is irrelevant that NAG can be converted to glufosinate in the gut as far as toxicity is concerned.
To conclude, it is true that transgenic glufosinate resistant plants metabolise glufosinate to NAG. It is also true that a small amount of NAG can be converted into glufosinate on passage through mammalian intestinal tracts. However, the rest of the steps required for Smith's "unique risk" do not occur. NAG appears only at low concentrations, if at all, in grain from glufosinate-treated crops and not at all in processed foods. Therefore, it would be exceptionally difficult to ingest sufficient NAG to even reach the ADI. The vast majority of the NAG and any glufosinate produced from it are excreted rapidly in faeces. Therefore, the chances of consuming sufficient NAG to convert to sufficient glufosinate in the gut to produce any measurable effect must be exceptionally remote.
You can read GMOPundit's take on this story at http://gmopundit.blogspot.com/2006/06/good-news-about-glufosinate-liberty.html. It appears this will be a chapter in Smith's new book: Genetic Roulette (http://gmopundit.blogspot.com/2006/03/new-book-on-gmos-by-jeffrey-m-smith.html). If the rest of the book is like this, it will be a prime example of shoddy scholarship and absolute speculation masquerading "as the world's most complete reference on the health risks of GM foods".