Just when you thought a nice plate of leafy greens was the perfect choice. Thanks to the wonders of modern retailing, pre-washed, pre-cut salad mixes—sometimes organically certified—are always just a "fresh pack" away. Not so fast. Before you place that pre-processed spinach, romaine, or mixed greens in your shopping basket, you may want to weigh the cost of that convenience.
These are troubling times in the nation's Salad Bowl. Nearly half of all the lettuce and three-quarters of all the spinach purchased in the United Sates originates in the Salinas Valley. Outbreaks of food poisoning and fatalities traced to a lethal strain of E. coli 0157 transported though bagged spinaches and lettuces grown in the Salinas Valley have shined a light on the human health risks associated with industrial-scale produce farming. In a desperate attempt to recover consumer confidence, shippers and buyers of leafy greens have issued new production standards (a.k.a. "metrics" and "super-metrics") pressuring growers to "clean up" their acts.
Clean farming means sterilizing their operations from seed planting to ice-packed, pre-washed salad mix. As well-intentioned as these efforts may have been, many observers argue that they have not been based on the best available science nor on sound food safety measures. In fact, these metrics could set off a domino effect of environmental degradation and human health risks in the Salad Bowl and farming regions around the country.
Who's At Fault
We may never discover the real source of the E. coli 0157 that contaminated the 2006 Dole spinach or the 2007 Taco Bell lettuce shipments. But there is no shortage of suspects. Standing at the top of the list—knee-deep in their own muck—are grain-fattened, antibiotic and hormone injected dairy and beef cattle, in whose over-acidified stomachs this particular strain of bacteria is thought to have originated as far back as 1982. Cattle grazing on pasture, particularly calves and adults stressed in warmer weather, can also harbor E. coli 0157. But this specialized bacteria tends to prefer the more acidic rumen of factory confined cows fed an unnatural diet of industrial corn.
Secondly there is the Salinas Valley groundwater, used for both crop irrigation and post-harvest processing. Runoff form manure in neighboring dairies or feedlots could have found its way into the water table, then into creeks, wells, and eventually into irrigation systems and processing pipelines. Leafy greens washed by mega-processors such as Natural Selection Foods, Fresh Pack, and others are commingled in these huge facilities—making it, literally, a giant salad bowl—heightening the odds of contamination. Studies from the University of California at Davis have shown, however, that even a small vegetated grass buffer can effectively filter toxins and keep them from the groundwater, including E. coli.
Finally, there is nature itself. Wildlife, including deer, feral pigs, and frogs have been suspected vectors, accused of tracking tainted cow manure across the agricultural landscape. Along with small rodents, these animals have also been charged as sources of the pathogen E. coli as well.
A War on Nature
Despite the unknowns, a few things are certain. In search of an immediate scapegoat, the leafy green industry quickly settled on nature as its primary culprit. Rather than attempting to restrict the most probable source of the E.coli 0157—manure from large confinement animal feedlot operations—the industry is directly targeting wildlife and the natural habitat that remains in the leafy green producing areas of the Salinas Valley. Strong-armed by distributors, farmers are removing vegetation buffers that once effectively filtered water and other contaminants flowing off fields. Chain link fences are being erected around tens of thousands of acres of owned and rented fields. Field margins are being scraped bare and denuded with herbicides. Small mammals and reptiles are being trapped and baited with poisons.
Driving this farm sterilization campaign are the metrics, or "best practices," that growers must adhere to if they want to stay in the ever-competitive leafy green game. The first was California's Leafy Green Marketing Agreement (LGMA), an alliance of large growers, shippers, and processors, that developed a set of grower guidelines—Good Agricultural Practices, or (GAP) metrics—to promote a safer form of leafy green production. These GAP metrics have since been superceded by a variety of other super-metrics, each more draconian than the last. Among other things, new best practices require: 450-foot bare earth buffers between crops and rivers or wildlife habitat and more than several hundred feet between crops and grazing lands. Even McDonalds and Wal-Mart are telling growers how to manage their lands by signing on to the Food Safety Leadership Council (FSLC) standards. These require the "reduction of the presence of reptiles, insects, birds, rodents," "a minimum of a quarter mile barrier between grazing lands adjacent growing fields," and that "surface water used for irrigation shall be free from weeds, trash, and foreign materials."
Bare Earth Bottom Line
Just six months after the 2006 spinach outbreak, a scorched earth policy was effectively underway in the Salad Bowl. A Monterey County Resource Conservation District survey indicated that growers managing 140,000 acres had adopted environmentally destructive measures in order to comply with food safety audit requirements and hold on to their eroding market share. Eighty-nine percent of growers responding reported actively eliminating conservation efforts to improve water quality or enhance wildlife habitat. Bare ground buffers, trapping, and poison bait stations emerged as common practice on over 90,000 acres. Nearly half the acreage was fenced.
Many farmers were conflicted by the challenges that these new food safety metrics posed to their own personal goals and approaches to farming and land stewardship. "Our experience," wrote one grower, "has been that the food safety auditors have been very strict about any vegetation that might provide habitat. We are very concerned about upsetting the natural balance, but we have to comply with out shipper's requests."
Hedgerows, streamside woodlands, and other natural habitats—many of them installed through taxpayer funded Farm Bill conservation programs—are crucial for healthy wildlife movement in a landscape already fragmented by agriculture. In the name of these food safety guidelines, the largely single-crop intensive landscape is being transformed into an industrial park. Growers are now reversing conservation gains which, in a bitter irony, could actually help protect the public from future pathogen E. coli 0157 outbreaks.
The Answer Might Be Blowing in the Wind
Research suggests another culprit on the loose, one overlooked by the initial scrutiny of industry and regulators. It is, in fact, a culprit that the LGMA's Gap Metrics and the other super-metrics might actually unleash on the landscape with a vengeance: dust. In January 2008, Dr. Charles Benbrook, chief scientist at the Organic Center, reported that a more probable source of pathogen E. coil 0157 in the Dole spinach outbreak was airborne dust, blowing from a cattle pasture to the north of the spinach field. Scientists only settled on dust as a possible transporter of the pathogen after a process of elimination. No E. coli 0157 was found in irrigation or processing water, Benbrook reported. He also noted that evidence discounts the feral pig hypothesis. Because of the location of the field, runoff from cattle pastures was also an extremely unlikely source.
"Ironically, the GAP Metrics' bare earth policies to discourage animals from venturing into leafy green fields might actually increase the risk of future outbreaks because bare ground around fields will increase dust," Benbrook said in an interview.
Beyond Bagged Spinach
Responses to the leafy green crisis can and must take place on a variety of levels. Most alarming are policies being considered at the national level (even through a proposed 2008 Farm Bill amendment) that—if implemented—could model scorched earth farming in other regions of the country, from the Salad Bowl to the citrus and tomato farms of Florida, to the orchards and vineyards of the Pacific Northwest, to a farming community near you. The fate of countless species is at stake, species that know no ownership boundaries, and depend on habitat in and around farming areas. Representatives must be held accountable, with polices and decisions based upon sound science rather than marketing objectives.
Through the power of the marketplace, the consuming public can also take action, by choosing not to buy pre-washed, pre-cut salad greens, even when this might be a hard habit to break. This will mean seeing these processed products for what they really are: industrially produced, convenience items, packed in their own pietre dishes, a sometimes expedient environment in which opportunistic pathogen E. coli can thrive. Alternatives exist and do not require that much extra effort or imagination. Whole heads of lettuces (washed in your own sink), bunches of fresh cut spinach or salad mixes from local farms eaten within a few days or a week of purchase. Processors of leafy greens could be required to shorten expiration periods in order to decrease the chances of contamination, according to Chuck Benbrook.
One can easily imagine a proliferation of fresh cut lettuces being grown in backyard garden beds throughout the country, protected from winter winds and chill by simple, inexpensive cover systems. Upwards of ten million Americans visit farmers markets once a week. What could be a more secure source of greens not grown at the expense of wild nature than those of a farmer that you know and trust?
Still, the big unresolved issue of animal factory farms that can't safely contain and process their toxic manure hangs over the country like a dark ominous cloud. Food poisoning through meat contamination continues to affect hundreds of thousands of people each year. Pollution from manure runoff during heavy rainfall is a great health risk. Even the current corn ethanol gold rush may be exacerbating the problem. With the proliferation of ethanol distilleries in agricultural areas across the nation, feedlot cattle are increasingly fed cheap "distiller grains," the spent byproducts of fuel fermentation. Recent studies suggest that these pre-processed grains may actually increase the production of pathogen E.coli if they become a larger ration of the feedlot diet. In the absence of a more trustworthy government and industry response, each and every concerned citizen should consider some personal platform on industrial meat and dairy production.
We have always faced uncertainties with our food supply. But scorching the earth to save industrial leafy green production points to a widening separation of agriculture and wild nature. It yields to the logic of industry and manufacturing without minding the wisdom of ecology, centuries old natural systems, or even the most basic bacteriology. Wild habitats in agricultural areas not only keep down dust and filter runoff, they harbor insects and other species that perform the essential functions of pollination and pest control, provide nesting opportunities for birds, create windbreaks, and add beauty to farmscapes. Secure food systems in an era of escalating petroleum prices will demand more regionally diversified farms and less dependence on faraway industrial monocultures—lots less. Convenience-oriented products like pre-washed, pre-cut, leafy greens produced on industrial farms adjacent industrial feedlots should be seen for what they ultimately are—a game of edible Russian roulette.
We have reached an age of increasing consequences. Simple choices, such as where and how our salad greens are produced, all matter. The good news is that we can all do something about it.
Note: For a thorough investigation into and background on this issue, including detailed photos, please visit The Wild Farm Alliance website: