Safe Food_ Bacteria, Biotechnology, and Bioterrorism - Marion Nestle [34]
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.34 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.35
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.”36 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.37