Flash Bulletin 2: Unintended Consequences Make Food Less Safe

Second of two briefs looking at critical topics to be explored in depth at the teach-in.

Bagged Salads
Although the origin of the E. coli 0157 that tainted those bags of spinach in 2006 was not determined, wildlife were quickly misconstrued as the most probable disease vector, and are a main focus of food safety auditor’s concerns to this day. Yet this decision to blame wildlife is not based primarily on facts but on marketing strategy, and the unreasonable stance that zero risk must be forged. Researchers in the field report that cattle are the major multiplier of 0157 on the landscape. Citing wildlife as the likely culprit took pressure off the processing aspect of the bagged salad industry, a factor that is likely a major cause of the problem, and helped companies gain markets back after the contamination. While wildlife can pose a low risk in some situations, eliminating their habitat has unintended consequences for food safety.

Grocery store buyers, shippers and processors are forcing farmers to comply with unscientifically based metrics that create sterile farm situations. Last year the Monterey County RCD’s food safety grower survey reported that farmers were having to use bare ground buffers and poison wildlife on about 100,000 acres, and put up wildlife exclusion fences on over 60,000 acres. This spring, the Wild Farm Alliance documented a mile of large riparian trees a 100’ wide taken out along California’s Salinas River, and the demolition of a 20-acre lake. This destruction occurs because many metrics intended to market safety require sterile ground buffers of up to 450’ between crops and habitat.

Removing habitat to safeguard food is counterproductive. Studies have shown that just one meter of grass can filter E. coli from a cow feces during a rainstorm. Windbreaks are known to cut down on dust movement, potentially blocking pathogen-laden soil from landing on crops. Removing habitat also runs counter to sustainable farming practices. By law, farmers are supposed to protect endangered species, water quality, and if organic, conserve biodiversity. Reducing vegetation next to rivers and ponds has the potential of harming protected species dependent on those habitats. Taking out grasses and wetlands that filter pathogens draining from areas with infected cattle and dismantling habitat that supports pollinators and other beneficial insects that prey on insect pests, damages ecosystems and may cause our food to be less safe.

Native wildlife pose little risk to food safety. Scientific journals and wildlife biologists only cite a few instances where 1-2% of deer populations studied in other states – states that don’t process salad greens – are carriers. In California, testing by Department of Fish and Game has so far found no E. coli O157 in deer. Other wildlife typically found on farms are not a significant threat. Many studies of native birds report 0% of the populations as carriers of 0157; while one study found 3%. The overwhelming information on prevalence of wild amphibians and reptiles to carry Salmonella, another food borne pathogen, is from other areas where salad mix is not grown, is really old or very specific for pet animals often held under stress. There may be some low level but at this point it has not been determined. In regard to field rodents such as ground squirrels, mice and gophers, a UC Cooperative Extension report concluded that based on current knowledge, trapping and poisoning them and removing their habitat does not benefit food safety efforts.

Feral pigs, and animals that exist near heavily 0157 polluted areas like those next to confined animal feeding operations (CAFOs) are another story. They have a much higher chance of being carriers. But because feral pigs are not native to the US, they do not have the instinct to hide from predators and no amount of habitat removal will deter them from crop fields – they are best hunted and trapped. In areas where commensal species like rats and starlings are found in close association with CAFOs, special care should be taken to ensure that 0157 stays there and infections do not spread, instead of indiscriminately removing all wildlife and habitat.

Food Safety Policies and Wildlife Management Have Been Mismatched Before
History of a different food safety issue – Brucellosis – in the grazing lands of the Midwest, provides another perspective on how food safety rules can lead to unintended consequences, and don’t necessarily address the real issues. For many decades the livestock industry has been operating under USDA rules that were designed to eradicate Brucellosis, a zoonotic disease that can cause undulant fever in humans. Onerous provisions, including depopulating entire cattle herds in response to one infected animal, or downgrading entire state’s trading status in response to just two infected herds, have left ranchers feeling the actions were disproportionately punitive for the last 30 years, since the disease is nearly eliminated in cattle today.

But a disease reservoir does remain---in the bison and elk of the Greater Yellowstone Area and current actions to kill bison straying from the Park have incensed environmentalists. Even though the disease was originally transmitted to wildlife from cattle, it is little wonder that the stringent response rules, coupled with no comprehensive plan to mitigate the current source, have led to ranchers’ resentment toward wildlife. Elk, however, are much more widely dispersed than bison, and they generate substantial hunting-related income in the region. Broad-scale slaughter is not an option. The result is a complicated patchwork of the cascading effects of maladapted policies.

Protecting Our Common Wealth
The FDA recently approved the irradiation of iceberg lettuce and spinach. While it might seem that this could take the pressure off wildlife, it is not seen as a viable option since the product does not keep as well and nutrition is diminished. This superficial fix does not get to the root of the problem – a food system allowing the mutation and proliferation of antibiotic resistant pathogens in CAFOs and the loss of antibiotic effectiveness. Nor does it narrow the focus to riskier bagged leafy greens, where much of the problem undoubtedly lies. More importantly though, this quick fix fails to address the misguided notion that wildlife and their habitat are the major cause of the trouble in the first place.

Farming and nature can coexist. Decisions must be made to protect the common wealth of human and wild communities – antibiotics that still work, clean drinking water and swimming areas, the right of farmers to benefit from natural pathogen-filtering processes, the right of consumers to eat healthy produce, and the prerogative of wildlife to exist for their own sake. It will take years to reorient our priorities, but such efforts are underway, and judicious media coverage of the complicated story will have an important role to play.

The purpose of the bulletin is to shed light on critical topics that will be explored in depth during the Teach-In, and to promote a greater understanding in America of food safety issues.