Safe Food: The Politics of Food Safety (10 page)

The most obvious effect of industry consolidation is to bring unimaginably large numbers of animals (or their meat) in close contact during production, transportation, slaughter, and processing. Raising large populations of chickens or cattle in one location means dealing with more manure than can possibly be contained or converted to fertilizer. Such practices have profound effects on the environment as well as on human health.
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When farmers raise just a few animals, they can compost the waste, a process that usually generates enough heat to kill bacteria. In addition to the environmental problems brought on by excessive manure, the use of raw—rather than composted—waste to fertilize fields and orchards brings pathogenic bacteria into contact with grains, vegetables, and fruits not usually contaminated with such organisms.
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The concentration of cattle production means that animals are transported across long distances, crowded together in railroad cars. Unlike poultry, beef cattle are shipped from one location to another at various growth stages—between the U.S. and Mexico, for example—increasing the opportunity for bacteria to spread. Large holding pens also expose animals to common sources of food and water, meaning that a foodborne or waterborne infection can quickly reach large numbers of animals. Animals
from many locations arrive at the slaughterhouse together and remain in close contact until killed; their carcasses remain in close contact until processed. Contact alone favors the spread of pathogens.

When it comes to processing, the implications of concentrated production are quite startling. Think, for a moment, about ground beef. To grind beef for hamburger, processors take beef from many sources—even from different states—mix it together and grind it. Packers regrind it, and grocers sometimes regrind it again. The result? Health officials estimate that just one infected beef carcass is sufficient to contaminate eight
tons
of ground beef. Even more remarkable, investigators once traced back the origin of a
single
lot of hamburger at one processing plant to slaughterhouses in six different states and to an almost unimaginable 443 individual animals.
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It is difficult to imagine a system better equipped to promote the spread of disease—and to obscure the source of illnesses or outbreaks.

Single-source outbreaks, however, also illustrate the vulnerability of a centralized food supply. In the most dramatic instance, a
Salmonella
outbreak in 1994 affected more than 220,000 people in 41 states. Its source was a surprise: packaged ice cream. The ice cream was produced from a premixed liquid base delivered to the processing plant in a tanker truck that previously had carried unpasteurized liquid eggs.
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Such incidents are fully preventable, as these chapters explain.

The use of antibiotics in animal agriculture affects foodborne illness in ways that are especially troubling. Growers treat infected animals with antibiotics, of course, but they sometimes give antibiotics to whole herds or flocks as a preventive measure. Despite the questionable effects of this practice, what most alarms safety experts is the
routine
use of low-dose antibiotic drugs as growth promoters, a practice that began in the 1950s and seems impossible to stop. Antibiotics are chemicals that prevent bacteria from reproducing (see
chapter 6
), but for reasons poorly understood, animals grow faster and need less feed when low-dose antibiotics are added to their food or drinking water. This treatment kills some bacteria, but not all; those naturally resistant to the antibiotics survive and multiply. The unintended consequence of this practice is the proliferation of antibiotic-resistant bacteria. If antibiotic-resistant bacteria infect people and cause disease, the disease will be untreatable.

This possibility is not merely theoretical. By the mid-1970s, researchers
already
knew that such uses increased the population of antibiotic-resistant bacteria in farm animals as well as in their human caretakers. In 1977, alarmed by such findings, the FDA proposed to restrict the use of antibiotics in animal feed. Congress, however, overruled this idea under pressure from farm-state lawmakers, livestock producers, and the makers of the drugs. These groups all argued that such restrictions were unwarranted because they were not sufficiently supported by science.
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This early blockage of safety regulations established a seemingly unshakable precedent.

In the following years, researchers reported that pathogenic bacteria resistant to
multiple
antibiotics could be passed from animals to humans. Every time the FDA attempted to restrict the use of the drugs, Congress again intervened, mainly as a result of drug industry lobbying and the invocation of “science” as an obstructive measure. Instead of taking action, Congress ordered the FDA to conduct further studies. By the early 1980s, the FDA stopped fighting this issue and instead proposed more relaxed standards, leading one Congressman to observe that the driving force behind the FDA’s retreat on this issue was “protection of the health of the animal drug industry.”
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In the mid-1990s, scientists demonstrated that
Campylobacter
resistant to high-potency antibiotics could be transferred from chickens to humans. The dangers of antibiotic-resistant foodborne bacteria were becoming more evident as more species acquired resistance to more and more antibiotics. Although calls for corrective action increased in urgency, a committee of the National Research Council (NRC) argued in 1999, “the use of drugs in the food-animal production industry is not without some problems and concerns, but it does not appear to constitute an immediate public health concern.”
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At least one critic viewed this surprisingly sanguine conclusion as just what one might expect when members of a scientific panel are “overwhelmingly associated with or linked to the drug industry.”
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During this period, the European Union (EU) banned four animal antibiotics and proposed a total ban on the use of antibiotics as growth promoters. U.S. agencies finally developed plans for dealing with the problem in 1999 and 2000. These plans are already too little, too late. In 2001, the
New England Journal of Medicine
reported that up to 80% of meat packages—pork, chicken, or beef—collected from local supermarkets contained antibiotic-resistant bacteria. These bacteria survived a week or two in the intestines of people who ate them; if these people became ill, the antibiotics would not help.
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Beef, pork, and poultry producers—and
drug manufacturers—continue to oppose restrictions on the use of antibiotics in animal agriculture. Their arguments: antibiotics are essential to their industries, most animal producers use antibiotics prudently, and the dangers of transfer of antibiotic resistance from animals to people are unproven. By one estimate, nearly 25 million pounds of antibiotics are used in animal agriculture, whereas just 3 million are used to treat human infections. Altogether, nearly three-fourths of all antibiotics are used for nontherapeutic purposes in animals. On this basis, consumer groups, food-safety alliances, and some members of Congress have called for outright bans on use of antibiotics in farm animals, except for therapeutic purposes.
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Given the disproportionate use of antibiotics in animal agriculture, it is not surprising that the drug industry opposes any suggestion to ban their use and much prefers “judicious use and robust surveillance” as control strategies.
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While the dispute rages on, the use of animal antibiotics continues. In this case, politics trumps science.

Two additional features of this situation are particularly compelling: (1) studies now indicate that induction of antibiotic resistance in bacteria is reversible, and (2) prevention of animal infections can be accomplished by means other than antibiotics. In 2002, Belgian researchers reported that banning certain antibiotics from use in animal feed decreases the prevalence of antibiotic-resistant bacteria and makes the drugs more effective in treating microbial illness in hospital patients. In part as a result of such findings, three large poultry producers in the United States announced in 2002 that they would reduce or eliminate the use of antibiotics in feed for healthy chickens.
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This action—if diligently taken—is a useful step in reducing antibiotic resistance.

Another idea is to prevent the proliferation of
E. coli
O157:H7 in animals without using antibiotics by changing the way they are fed. Typically, producers feed cattle soy and corn to fatten the animals just before slaughter; these foods are low in fiber, reduce the acidity of digestive solutions, and promote the growth of unfriendly bacteria. In contrast, feeding high-fiber hay to ruminant animals selects for friendlier bacteria capable of breaking down cellulose to usable nutrients. Animals fed hay prior to slaughter generate less than 1% of the
E. coli
O157:H7 usually present in the feces of grain-fed animals, and they become free of the undesirable bacteria in just a few days. Adding certain strains of lactic acid bacteria—a friendly species—to cattle feed also interferes with the proliferation of
E. coli
O157:H7. The identification of
E. coli
O157:H7 infections in increasing numbers of farm animals makes such methods especially
attractive as preventive measures.
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Such low-tech approaches are unlikely to appeal to meat producers concerned about putting the maximum possible weight on their animals, however, or to drug companies eager to continue selling antibiotics to meat producers; billions of dollars are at stake. The government cannot intervene in this matter because, as the next chapter explains, USDA authority begins at the slaughterhouse; the agency has no authority whatsoever over farm practices.

Changes in society and in the behavior of consumers also contribute to the spread of harmful bacteria in food.
Table 5
(
page 43
) summarizes them. Women left home to go to work, commuting distances increased, and work hours lengthened. As a result, convenience is a critically important issue in food choice. People eat more food outside the home and more food prepared in advance by others. Meals prepared in restaurants and other institutions account for roughly half of all national food expenditures. Centralized food production, of course, presents ample opportunities for spreading microbial pathogens from a common source.

Preferences for fresh fruits and vegetables—the object of much nutritional advice—also present such opportunities. Demands for strawberries and tomatoes in winter require fruits and vegetables to be imported from warmer countries in Asia, Latin America, and North Africa, where water quality and sanitation facilities do not necessarily meet U.S. standards. An unchlorinated water supply in a developing country is a good reason to avoid eating its vegetables raw, or its fruit unpeeled. Nevertheless, the United States imported nearly $1.4 billion worth of fresh vegetables (asparagus, cucumbers, peppers, tomatoes, and others) from one such country, Mexico, in 2000. Imported fruits and vegetables are supposed to meet U.S. sanitation standards, but sometimes do not.
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Dealing with the safety of imported produce is politically sensitive on a number of levels. If we reject foods from a developing country, we hurt its economy. But if we accept them without more stringent controls, we make the foods more vulnerable to contamination or to threats of bioterrorism, as we will see in the concluding chapter.

Efforts to market fruits and vegetables in forms that require less preparation time and are more convenient for consumers also create opportunities for cross-contamination. Precut fruits and vegetables, preprepared salad mixes, salad bar items, and packaged juices all require handling, transport, and storage. Such foods increasingly become sources
of outbreaks. Problems occur when the foods come in contact with animal feces prior to processing, with contaminated equipment during processing, or with infected people who handle them at any point.

Even when foods are cooked or pasteurized, they can be recontaminated. Foods prepared in supermarkets, restaurants, and convenience stores are often made in advance and stored for hours, allowing time for bacteria to proliferate. It was a relief to read about a 1999 investigation of New York City salad bars that found no trace of
E. coli
O157:H7. Investigators discovered that foods in some of these places exceeded allowable limits of
Salmonella
, however.
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The more people who handle foods between harvest and consumption, the greater the chance of passing along a foodborne illness. Thus, working conditions are critical factors in food safety. To pick just one example: when the rules in meatpacking plants restrict bathroom breaks, workers are forced, as one investigator puts the matter, to “urinate on the job.”
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Many jobs in food preparation and service pay minimum wages and provide no health care benefits or paid sick-leave—conditions that encourage people to work while they are ill. Workers in low-paying jobs are rarely trained in food safety. When such training is available, it usually requires proficiency in English. Workers who cannot understand food safety instructions or the importance of basic preventive measures (hand washing, for example) are not likely to follow safe procedures for food handling. A final factor is demographic. Because the population of the United States is aging rapidly, overall susceptibility to foodborne illness is increasing. From 1965 to 1995, the number of Americans aged 65 and over grew by 82%; one-fifth of the population is expected to be older than 65 within the next three decades. Immune function declines somewhat with age, but medications are a greater problem. Older adults often take multiple medications to treat whatever ailments they may have, and the drugs—paradoxically—sometimes compromise immune function and increase vulnerability to infectious agents.
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