Thursday, October 7th, 2010
There’s a new paper in this week’s issue of Science that suggests that growing a landscape mixed with genetically modified (GM) Bt corn and non-GM hybrid varieties of corn can be mutually beneficial to all corn farmers.
Why? They argue that the populations of GM corn knock down the populations of insect herbivores enough that, on a landscape scale, this effect spills over to nearby farmers growing non-GM corn, which raises yields and profits:
[W]e estimate that cumulative benefits for both Bt and non-Bt maize growers during the past 14 years were almost $6.9 billion in the five-state region (18.7 million ha in
2009)—more than $3.2 billion in Illinois, Minnesota, and Wisconsin, and $3.6 billion in Iowa and Nebraska. Of this $6.9 billion total, cumulative suppression benefits to non-Bt maize growers resulting from O. nubilalis [European corn borer] population suppression in non-Bt maize exceeded $4.3 billion—more than $2.4 billion in Illinois, Minnesota, and Wisconsin, and $1.9 billion in Iowa and Nebraska—or about 63% of the total benefits.
They suggest that the populations of non-GM corn also benefit the Bt corn farmers because the non-GM corn maintains a genetically diverse population of insects, helping prevent the evolution of herbivores resistant to Bt corn.
These results are interesting and —if they hold—could be an example of how GM crops bring environmental and social benefits. A good outcome for all.
However, there are a couple of important things to consider:
(1) The notion of mixing crop types to minimize herbivory is the one of the fundamental tenets of traditional agroecology and organic agriculture, but instead of relying on GM crops, it could be done with a mix of hybrid crop varieties that doesn’t risk the potential environmental side effects of Bt corn or other unexpected outcomes of GM crops. This is a major value judgment. Does having one GM crop and a few dominant corn varieties count as diversity when the Midwest becomes a giant sea of maize? As I explain in #2 below, probably not. Could we achieve the same kind of insect pest management using a diversity of non-GM crops? Yes—it happens all the time in midwestern organic farms. Multi-crop organic farming is often more labor intensive than industrial agriculture, making the food produced more expensive. But do we only care about cheap food?
(2) I’ve lived in southern Minnesota, where it’s a giant rotating monoculture of corn and soybeans. If you look at Figure 1 in this paper, you will see that 50-75% (or more) of the corn grown in many regions of states like Iowa, Nebraska, and Minnesota is Bt corn. When so much of your landscape is Bt corn, the evolution of resistance to Bt is most likely inevitable, as we saw in a previous post with the use of Roundup-ready crops like soybeans, which are often grown in rotation with Bt corn in these regions. Acknowledging this fact of life, EPA recommends mixing GM and non-GM corn in an effort to delay the evolution of resistance, not prevent it:
To delay evolution of resistance, the U.S. Environmental Protection Agency (EPA) mandated that a minimum 20 to 50% of total onfarm maize be planted as non-Bt maize within 0.8 km of Bt fields as a structured refuge for susceptible O. nubilalis. Use of non-Bt maize refugia is an important element of long-term insect resistance management.
…Sustained economic and environmental benefits of this technology, however, will depend on continued stewardship by producers to maintain non-Bt maize refugia to minimize the risk of evolution of Bt resistance in crop pest species, and also on the dynamics of Bt resistance evolution at low pest densities and for variable pest phenotypes.
Hutchison, W., Burkness, E., Mitchell, P., Moon, R., Leslie, T., Fleischer, S., Abrahamson, M., Hamilton, K., Steffey, K., Gray, M., Hellmich, R., Kaster, L., Hunt, T., Wright, R., Pecinovsky, K., Rabaey, T., Flood, B., & Raun, E. (2010). Areawide Suppression of European Corn Borer with Bt Maize Reaps Savings to Non-Bt Maize Growers Science, 330 (6001), 222-225 DOI: 10.1126/science.1190242
Photo credit: Ian Hayhurst
Monday, September 27th, 2010
Genetically modified organisms (GMOs) are back in the news. A few days ago, NPR featured a couple of blog posts (here and here) considering whether the new GMO “supersized” salmon will be harmful to aquatic ecosystems.
A concern with GMOs is that—like the early adoption of pesticides—potential risks are being borne by the environment and consumers as we experiment with new species. There’s a lot of potential for GMOs, and I hope that they all end up being harmless. But there are potential downsides too that we are not able to assess very well at this point. And we may be creating problems that we are not even aware of yet.
As more data come in, it’s not always an encouraging outlook. A couple of recent examples:
Case #1: We saw a few months ago how weeds that were supposed to be eliminated by the agricultural herbicide, Roundup, are now evolving resistance to the chemical, meaning that Roundup-ready soybeans and other crops no longer work as designed.
Case #2: In this week’s Early Edition of the Proceedings of the National Academy of Sciences, Jennifer Tank and colleagues examined what happens to transgenic corn residue (old crop parts left on fields that are not harvested). One of the main transgenic varieties of corn is known as “Bt corn.” Bt stands for the name of a microbe—Bacillus thuringiensis—that makes a protein toxin that destroys the functioning of guts in some insects. Scientists have figured out how to move the Bt gene, and hence Bt toxin manufacturing capacity, from the bacteria to corn plants, thereby conferring general insect herbivore resistance to this crop (the main pest being the European corn borer).
This team asked: What happens when corn stalks, cobs, and leaves end up in streams and rivers throughout the Midwest? Their answer is eye-opening:
Widespread planting of maize throughout the agricultural Midwest may result in detritus entering adjacent stream ecosystems, and 63% of the 2009 US maize crop was genetically modified to express insecticidal Cry proteins derived from Bacillus thuringiensis. Six months after harvest, we conducted a synoptic survey of 217 stream sites in Indiana to determine the extent of maize detritus and presence of Cry1Ab protein in the stream network. We found that 86% of stream sites contained maize leaves, cobs, husks, and/or stalks in the active stream channel. We also detected Cry1Ab protein in stream-channel maize at 13% of sites and in the water column at 23% of sites. We found that 82% of stream sites were adjacent to maize fields, and Geographical Information Systems analyses indicated that 100% of sites containing Cry1Ab-positive detritus in the active stream channel had maize planted within 500 m during the previous crop year. Maize detritus likely enters streams throughout the Corn Belt; using US Department of Agriculture land cover data, we estimate that 91% of the 256,446 km of streams/rivers in Iowa, Illinois, and Indiana are located within 500 m of a maize field. Maize detritus is common in low-gradient stream channels in northwestern Indiana, and Cry1Ab proteins persist in maize leaves and can be measured in the water column even 6 mo after harvest. Hence, maize detritus, and associated Cry1Ab proteins, are widely distributed and persistent in the headwater streams of a Corn Belt landscape.
Who cares? Streams and rivers are the breeding grounds to many insect species, including dragonflies, mayflies, and damselflies. If there are toxins floating in these aquatic ecosystems that are good at killing insects, there is risk of disrupting food webs, including potential changes to bird species as well as many important recreational and sport fish that dine on insects:
Once maize detritus enters stream channels, this carbon source degrades rapidly via a combination of microbial decomposition, physical breakdown, and invertebrate consumption, and that energy may fuel stream food webs. Maize detritus in agricultural streams decomposes in ∼66 d …. Therefore, the material that we found during our synoptic survey had entered these streams relatively recently. Maize detritus is rapidly colonized by stream-dwelling invertebrates, and growth rates of invertebrates feeding on nontransgenic decomposing maize are comparable to those feeding on the deciduous leaf litter commonly found in forested streams
Perhaps this means that the Bt toxins might break down quickly and pose less harm? Doesn’t look like it:
Our data demonstrate that long after harvest, Cry1Ab is present in submerged Bt maize detritus; thus, stream organisms may be exposed to Cry1Ab for several months.
It’s also interesting to learn that low or no-till conservation tillage practices may exacerbate the corn residue inputs because greater material left on fields is susceptible to washing away:
The dried detritus left on fields after harvest, as part of conservation tillage, enters headwater streams as a result of surface runoff and/or wind events occurring throughout the year. During heavy precipitation, overland flow is the likely mechanism transporting this material to stream channels.
It may not even be a matter of leaving less residue; the toxins also appear to be draining through the soils:
Our results from tile drains indicate that tiles may be a mechanism by which Cry1Ab leached from detritus on fields or from soils can be transported to streams.
Cry1Ab released from root exudates or decaying maize detritus moves vertically through soils and can be detected at the base of 15-cm-long soil profiles for up to 9 h.
Their conclusion? An illustration of how little we know at this point:
The question of whether the concentrations of Cry1Ab protein we report in this study have any effects on nontarget organisms merits further study.
Jennifer L. Tank, Emma J. Rosi-Marshall, Todd V. Royer, Matt R. Whiles, Natalie A. Griffiths, Therese C. Frauendorf, and David J. Treering (2010). Occurrence of maize detritus and a transgenic insecticidal protein (Cry1Ab) within the stream network of an agricultural landscape Proceedings of the National Academy of Sciences : 10.1073/pnas.1006925107
Photo credit: snake.eyes
Sunday, September 26th, 2010
The NY Times and Huffington Post are running a story by Kim Severson, Told to Eat Its Vegetables, America Orders Fries, lamenting how hard it is to get people to eat healthy.
The thing that struck me about this article, as its title suggests, is how nutrition in America is often pitched top-down. A strategy is bound to fail when it consists simply of government experts making recommendations about nutrition, as one of the folks interviewed notes:
“It is disappointing,” said Dr. Jennifer Foltz, a pediatrician who helped compile the report. She, like other public health officials dedicated to improving the American diet, concedes that perhaps simply telling people to eat more vegetables isn’t working.
…The government keeps trying, too, to get its message across. It now recommends four and a half cups of fruits and vegetables (that’s nine servings) for people who eat 2,000 calories a day. Some public health advocates have argued that when the guidelines are updated later this year, they should be made even clearer. One proposal is to make Americans think about it visually, filling half the plate or bowl with vegetables.
The article explores the usual things claimed to be preventing people from eating better—convenience and cost:
“The moment you have something fresh you have to schedule your life around using it,” Mr. Balzer said.
In the wrong hands, vegetables can taste terrible. And compared with a lot of food at the supermarket, they’re a relatively expensive way to fill a belly.
“Before we want health, we want taste, we want convenience and we want low cost,” Mr. Balzer said.
Melissa MacBride, a busy Manhattan resident who works for a pharmaceuticals company, would eat more vegetables if they weren’t, in her words, “a pain.”
“An apple you can just grab,” she said. “But what am I going to do, put a piece of kale in my purse?”
“It’s just like any other bad habit,” he said. “Part of it is just that vegetables are a little intimidating. I’m not afraid of zucchinis, but I just don’t know how to cook them.”
The solution is presented as a problem of overcoming access to good food:
But clear guidance probably isn’t enough. Health officials now concede that convincing a nation that shuns vegetables means making vegetables more affordable and more available.
I’m a fan of nutritional literacy, as I am with environmental literacy, but only as one of several approaches in a portfolio of strategies for improving the quality of life and the environment. Nutritionists and climate change educators should team up in this regard because they face the same challenge—winning hearts and minds (or, in this case, stomachs) and changing behavior.
The problem is that a top-down nutritional literacy approach, by itself, is woefully inadequate (more information, alone, simply won’t accomplish this), and access to good food is only part of the challenge.
If you want engagement, then nutrition needs to be turned into a bottom-up venture. It’s not simply a matter of food pyramids and access to good food. People need to experience growing and cooking their own food. They need to be engaged with how good it can be, how it can be grown cheaply, and how plant-based diets are easy to prepare.
There are several ways to begin accomplishing this:
1. Start early. Make gardening and cooking a part of the elementary school experience. All kids should take an active role in planting, tending, and harvesting food. Then they should take part in preparing the foods they have grown in ways that are appealing to eat. The power of this should not be underestimated. The only thing I remember from kindergarten is making bread and butter from scratch.
2. Diffuse this knowledge to home or community gardens. When kids are taught how to prepare healthy, tasty food, they can bring what they learn home, starting home gardens and helping out with making dinner by showing parents what they learned in school (maybe accompanied by some kind of creative incentive from parents to do this). People can see for themselves that is is often less expensive to grow healthy food, especially if communities team up and share their bounties, than it is to buy junk food that makes up much of their diet.
3. Involve the community in a contest to generate a list of the most popular recipes for different fruits and vegetables. Perhaps engage the help of local chefs for fun. I have a 100% whole fruit smoothie recipe that most kids would mistake for dessert.
4. Disperse these recipes widely and incorporate them into school education programs and lunches, as Alice Waters is accomplishing in California.
5. Not only should farmers markets accept SNAP (food stamps), there should be classes/demos to show people how to prepare foods. Also, having samples and recipes that are tasty and convenient would be helpful. People should be convinced, by seeing with their own eyes and taste buds, that they can do this and that it’s worth their time.
And that’s part of the larger problem: overcoming the psychological barrier that fresh food prep is time consuming:
“The moment you have something fresh you have to schedule your life around using it.”
Although I see the point here, I think it’s a poor reason for not eating healthy. People schedule time around education, sleeping, exercising, soccer practice, vacation, being with friends, spirituality, and visits to the doctor/dentist because these things are considered necessary to living well. Is preparing healthy food not a similarly meaningful part of our lives? Is it really impossible for families to schedule 30-45 minutes preparing meals? Should leisure time or other competing interests really be that high an opportunity cost?
Perhaps that’s one lesson: So long as Americans treat preparing and enjoying healthy meals as a tradeoff with leisure time or other activities, American diets will suffer. No amount of top-down government nutrition guidelines will overcome that.
Related news: Bill Clinton now eats vegan
Photo credit: hellochris
Tuesday, September 14th, 2010
Erik Eckholm’s article in today’s NY Times suggests that the movement to limit antibiotics use in healthy farm animals is gaining momentum in the Obama Administration and Congress (links his):
Dispensing antibiotics to healthy animals is routine on the large, concentrated farms that now dominate American agriculture. But the practice is increasingly condemned by medical experts who say it contributes to a growing scourge of modern medicine: the emergence of antibiotic-resistant bacteria, including dangerous E. coli strains that account for millions of bladder infections each year, as well as resistant types of salmonella and other microbes.
Now, after decades of debate, the Food and Drug Administration appears poised to issue its strongest guidelines on animal antibiotics yet, intended to reduce what it calls a clear risk to human health. They would end farm uses of the drugs simply to promote faster animal growth and call for tighter oversight by veterinarians.
The agency’s final version is expected within months, and comes at a time when animal confinement methods, safety monitoring and other aspects of so-called factory farming are also under sharp attack. The federal proposal has struck a nerve among major livestock producers, who argue that a direct link between farms and human illness has not been proved. The producers are vigorously opposing it even as many medical and health experts call it too timid.
Scores of scientific groups, including the American Medical Association and the Infectious Diseases Society of America, are calling for even stronger action that would bar most uses of key antibiotics in healthy animals, including use for disease prevention, as with Mr. Rowles’s piglets. Such a bill is gaining traction in Congress.
“Is producing the cheapest food in the world our only goal?” asked Dr. Gail R. Hansen, a veterinarian and senior officer of the Pew Charitable Trusts, which has campaigned for new limits on farm drugs. “Those who say there is no evidence of risk are discounting 40 years of science. To wait until there’s nothing we can do about it doesn’t seem like the wisest course.”
Read more of the article here.
Photo credit: crispyking
Monday, May 17th, 2010
MSNBC is reporting today on new research suggesting that some pesticides may double the rate of ADHD (attention deficit hyperactivity disorder) in kids.
Youngsters with high levels of pesticide residue in their urine, particularly from widely used types of insecticide such as malathion, were more likely to have ADHD, the behavior disorder that often disrupts school and social life, scientists in the United States and Canada found.
Kids with higher-than-average levels of one pesticide marker were nearly twice as likely to be diagnosed with ADHD as children who showed no traces of the poison.
The take-home message for parents, according to Bouchard: “I would say buy organic as much as possible,” she said. “I would also recommend washing fruits and vegetables as much as possible.”
As discussed in a previous post “Do our daily routines put our health at risk?” here’s an easy to use shopping guide of which fruits and vegetables to buy organic.
Monday, May 3rd, 2010
The NY Times is running a cover story on how crop weeds are becoming resistant to one of the most ubiquitously used herbicides—Roundup.
This is the herbicide that farmers can spray on genetically modified crops that are resistant to its damage. It’s widely used on major crops, such as soy, corn, canola, sugar beet, and cotton.
In theory, all weeds other than the GM crop succumb to the chemical. As the Times story suggests, that’s not the case anymore because weeds are evolving resistance, possibly rendering Roundup and Roundup-ready GM crops ineffective.
Just as the heavy use of antibiotics contributed to the rise of drug-resistant supergerms, American farmers’ near-ubiquitous use of the weedkiller Roundup has led to the rapid growth of tenacious new superweeds.
To fight them, Mr. Anderson and farmers throughout the East, Midwest and South are being forced to spray fields with more toxic herbicides, pull weeds by hand and return to more labor-intensive methods like regular plowing.
“We’re back to where we were 20 years ago,” said Mr. Anderson, who will plow about one-third of his 3,000 acres of soybean fields this spring, more than he has in years. “We’re trying to find out what works.”
Farm experts say that such efforts could lead to higher food prices, lower crop yields, rising farm costs and more pollution of land and water.
“It is the single largest threat to production agriculture that we have ever seen,” said Andrew Wargo III, the president of the Arkansas Association of Conservation Districts.
…If frequent plowing becomes necessary again, “that is certainly a major concern for our environment,” Ken Smith, a weed scientist at the University of Arkansas, said. In addition, some critics of genetically engineered crops say that the use of extra herbicides, including some old ones that are less environmentally tolerable than Roundup, belies the claims made by the biotechnology industry that its crops would be better for the environment.
“The biotech industry is taking us into a more pesticide-dependent agriculture when they’ve always promised, and we need to be going in, the opposite direction,” said Bill Freese, a science policy analyst for the Center for Food Safety in Washington.
Friday, March 19th, 2010
European bee populations are on the decline worldwide. Who cares? These bees are major pollinators of crops and therefore perform, for free, a vital ecological service worth about $U.S. 14 billion per year. Not to mention the many other species of non-crop flowering plants that reproduce with the help of insects like this.
The recent kind of decline is specific—only female worker bees disappear—and has been given the name colony collapse disorder (CCD). Nobody has figured out why this is happening. The potential list of culprits includes mites, viruses, synthetic chemicals, and other factors.
In an article this week in PLoS ONE, Christopher Mullin and colleagues explore further the potential link between pesticides and CCD.1
One third of honey bee colonies in the US were lost during each of the last three winters between ’06-’09. This alarming overwinter along with other losses of this primary pollinator, Apis mellifera L., as well as those of native pollinators, has been documented in North America and Europe. The most recent manifestation of this decline, Colony Collapse Disorder (CCD), has led to a significant collaborative effort involving several land grant universities, Departments of Agriculture and the USDA.
We have found 121 different pesticides and metabolites within 887 wax, pollen, bee and associated hive samples. Almost 60% of the 259 wax and 350 pollen samples contained at least one systemic pesticide, and over 47% had both in-hive acaricides fluvalinate and coumaphos, and chlorothalonil, a widely-used fungicide. In bee pollen were found chlorothalonil at levels up to 99 ppm and the insecticides aldicarb, carbaryl, chlorpyrifos and imidacloprid, fungicides boscalid, captan and myclobutanil, and herbicide pendimethalin at 1 ppm levels. Almost all comb and foundation wax samples (98%) were contaminated with up to 204 and 94 ppm, respectively, of fluvalinate and coumaphos, and lower amounts of amitraz degradates and chlorothalonil, with an average of 6 pesticide detections per sample and a high of 39. There were fewer pesticides found in adults and brood except for those linked with bee kills by permethrin (20 ppm) and fipronil (3.1 ppm).
The 98 pesticides and metabolites detected in mixtures up to 214 ppm in bee pollen alone represents a remarkably high level for toxicants in the brood and adult food of this primary pollinator. This represents over half of the maximum individual pesticide incidences ever reported for apiaries. While exposure to many of these neurotoxicants elicits acute and sublethal reductions in honey bee fitness, the effects of these materials in combinations and their direct association with CCD or declining bee health remains to be determined.
The high frequency of multiple pesticides in bee collected pollen and wax indicates that pesticide interactions need thorough investigation before their roles in decreasing bee health can be either supported or refuted. The large number of studies to date, are limited by being done on mostly one compound at a time, as well as using whole colonies where the timing of contaminated pollen intake and its utilization by the colony are difficult to interpret as a causal relationship. Laboratory studies have clearly indicated sublethal impacts on honey bee learning, immune system functioning, and synergism of insecticide toxicity by fungicides, yet combinations of herbicides with fungicides and insecticides in 3 or more component mixtures have not been studied.
The widespread occurrence of multiple residues, some at toxic levels for single compounds, and the lack of any scientific literature on the biological consequences of combinations of pesticides, argues strongly for urgent changes in regulatory policies regarding pesticide registration and monitoring procedures as they relate to pollinator safety. This further calls for emergency funding to address the myriad holes in our scientific understanding of pesticide consequences for pollinators. The relegation of bee toxicity for registered compounds to impact only label warnings, and the underestimation of systemic pesticide hazards to bees in the registration process may well have contributed to widespread pesticide contamination of pollen, the primary food source of our major pollinator. Is risking the $14 billion contribution of pollinators to our food system really worth lack of action?
1Christopher A. Mullin, Maryann Frazier, James L. Frazier, Sara Ashcraft, Roger Simonds, Dennis vanEngelsdorp, Jeffery S. Pettis (2010). High Levels of Miticides and Agrochemicals in North American Apiaries: Implications for Honey Bee Health PLoS ONE
Wednesday, December 2nd, 2009
Think of all the reasons why people advocate sustainable food, and the following things probably come to mind:
How about this one?
Not so much.
And that’s probably why Caitlin Donohue wrote the story, “Out of reach: How the sustainable local food movement neglects poor workers and eaters” in today’s San Francisco Bay Guardian Online.
There’s a lot more that can be written on this topic, and there are a growing number of success stories, including
The introduction to Donohue’s article frames the cultural disconnect:
On a sunny afternoon in Civic Center Plaza, a remarkable bounty covered a buffet table: coconut quinoa, organic mushroom tabouli, homemade vegan desserts, and an assortment of other yummy treats. The food and event were meant to raise awareness about public school lunches, although it was hard to imagine these dishes, brought by well-heeled food advocates, sitting under the fluorescent lights of a San Francisco public school cafeteria.
The spread was for the Slow Food USA Labor Day “eat-in,” a public potluck meant to publicize the proposed reauthorization of the Child Nutrition Act, national legislation that regulates the food in public schools. The crowd was in a festive, light-hearted mood. There was a full program of speeches by sustainability experts and a plant-your-own-vegetable-seeds table set up in one corner of the plaza.
A bedraggled couple who appeared homeless made their way through the jovial crowd and started scooping up the food in a way that suggested it had been a long time since their last roasted local lamb shish kebob.
Their presence shouldn’t have been a surprise; most events involving free trips down a food table are geared toward a different demographic in this park, which borders the Tenderloin.
In a flash, an event volunteer was on the case, nervous in an endearingly liberal manner. “Sir,” she began. “This food is for the Child Nutrition Act.” And then she paused, searching for what to say next. I imagined her thinking: “Sir, this food is to raise awareness about the availability of sustainable food to the lower classes, not to be eaten by them,” or, “Sir, this good, healthy, local food is not for you.”
Continue reading here…
Friday, November 20th, 2009
There’s a new guide to shopping that looks interesting. It’s called Good Guide, and it helps people learn more about what’s in their products that might not be healthy–to you, the environment, or society.
It’s easy to click on many different product types—from food to personal products to air fresheners to toys. For example, ever wonder about different kinds of mac and cheese?
Here’s more information about them:
What chemicals are in your baby shampoo?
Was sweatshop labor used to make your t-shirt?
What products are the best, and what products should you avoid?
Increasingly, you want to know about the impacts of the products you buy. On your health. On the environment. On society. But unless you’ve got a Ph.D, it is almost impossible to find out the impacts of the products you buy. Until now…
GoodGuide provides the world’s largest and most reliable source of information on the health, environmental, and social impacts of the products in your home.
With GoodGuide, you can:
Related post: Do our daily routines put our health at risk?
Wednesday, November 11th, 2009
Nicolette Niman has a new column, Avoiding Factory Farm Foods: An Eater’s Guide, this week at Huffington Post. This follows her NY Times column last week, Carnivore’s Dilemma, of which I was somewhat critical for the notable absence of land use concerns in the sustainable meat industry.
It’s a personal story that complements Jonathan Safran Foer’s recent thoughts on vegetarianism as a response to factory farming. I was surprised to learn that someone known for her family’s more-sustainable livestock ranch network is actually vegetarian.
Here are her main points on avoiding factory farmed foods. Her article provides more details on each: