An Explainer roundup on food contamination.

An Explainer roundup on food contamination.

An Explainer roundup on food contamination.

Answers to your questions about the news.
Nov. 5 2009 5:10 PM

Dirty Beef

… and other alimentary concerns. An Explainer roundup.

Two people have died, and 28 have fallen sick, due to an E. coli outbreak in ground beef, the Centers for Disease Control and Prevention reported this week. This latest scare follows an October New York Times article on pervasive flaws in the beef-inspection process, featuring a woman who became paralyzed after eating hamburgers tainted with E. coli in 2007. Panicked? Here's an Explainer roundup on food contamination.

What should you do if you've eaten a recalled product?
Wait and see. Just because a product was recalled doesn't mean it was contaminated. (That's why companies like to emphasize the word voluntary when they pull food off the shelves.) And exposure doesn't mean you'll get sick. But most people exposed to salmonella—bacteria that originate in the feces of animals and humans—do develop diarrhea, fever, and abdominal cramps within 12 to 72 hours. If this happens, you should call a doctor, who might prescribe antibiotics or just tell you to drink lots of fluids. Often the sickness will pass in four to seven days, although in more severe cases—when bacteria get into the bloodstream—salmonella poisoning can lead to arterial infections, heart inflammation, and Reiter's syndrome, a form of arthritis. These extreme reactions are most common among the young, the elderly, and people with compromised immune systems. If you find a defective item in your pantry at home, most companies will either replace it or give you your money back. You might also have a chance of winning cash in a lawsuit, but only if you get sick. People who sue companies over food-borne illnesses have to demonstrate fault, causation, and damages. (For more detail, read this Explainer from January.)

If I become a vegan, I'll never have to worry about food safety again, right?
Wrong. Poultry, meat, and eggs provide the most common source of salmonella infection and the associated disease "salmonellosis." The bacteria live in animals like cattle and birds and can easily be passed along in raw animal products. But the feces of infected animals can also contaminate many other foods, like fresh fruits and vegetables. In 2007, Dole recalled cantaloupes that contained the bacteria, and in 2004, Roma tomatoes were contaminated. (For more detail, read this Explainer from 2007.)

In 2007, salmonella-tainted tomatoes sickened more than 100 people. How can salmonella, a bacterium that normally lives inside animal intestines, get on your tomatoes?
Manure, runoff, and wild animals. Livestock animals, especially when kept in large numbers in confined spaces, can contract salmonella and carry the bug without showing any symptoms at all. Infected cows, pigs, and chickens shed the bacteria in their waste, which is sometimes used to fertilize nearby fields. The heat generated when manure is composted kills off most, but not all, disease-causing bacteria. Contaminated water supplies can also put salmonella on your tomatoes. Runoff from livestock pastures, or from leaky or overtopped waste lagoons at industrial farming sites, can dirty streams, groundwater, and other bodies of water farmers draw on for irrigation. According to an FDA investigation, that was the likely cause of a 2002 salmonella outbreak in imported Mexican cantaloupes. (For more detail, read this Explainer from 2008.)

Will washing my fruits and vegetables cut down on the threat of contamination?
Probably. According to food safety experts, a "thorough rinsing" can cut down on microbacteria by as much as 90 percent—the remaining decile of disease is lodged in grooves on the produce's surface or attached to it by electrostatic charges. The longer the bacteria stay on, the more attached they get. Washing is more helpful in getting rid of "spoilage bacteria"—giving something a rinse before putting it in the fridge might help make it last longer. (For more detail, read this Explainer from 2006.)

The woman featured in the New York Times story ate a burger labeled "American Chef's Selection Angus Beef Patties." What is Angus beef, anyway?
A Scottish breed of cattle. Formerly called Aberdeen Angus after their place of origin, Angus cattle are among the most commonly used breeds in American beef production. They're popular among consumers because they have more meat on their bones than other breeds and because their meat has distinctive "marbling"—flecks of fat, which contribute to flavor and texture. Although the breed has a relatively upscale reputation, there's nothing necessarily superior about Angus beef, which comes in various grades, or levels of quality, as determined by the United States Department of Agriculture: prime, choice, select, commercial, utility, and cutter.

Angus the breed is not synonymous with the brand "Certified Angus Beef"—an upmarket product started in 1978 by the American Angus Association. CAB sells only beef that's in the top two-thirds on the USDA quality scale—it must be prime or choice, with "modest" marbling, a 10- to 16-square-inch rib-eye area, and no "neck hump" that exceeds 2 inches. McDonald's, by contrast, offers Angus burgers but doesn't claim to impose the same stringent requirements. (For more detail, read this Explainer from October.)

Back in 2008, Hallmark Meat Packing recalled its entire beef supply from the two years prior due to the improper slaughtering of sick cattle. Why recall meat that was sold two years ago?
Because it's possible that someone hasn't eaten it yet. Recalls of this kind extend as far back as there is evidence of safety violations. In many cases, this can be limited to meat packaged on a specific day or over the course of a given week, but the evidence of noncompliance at Hallmark was a more consistent problem, dating back at least two years. It's possible there were even earlier violations—which might merit an even more extensive recall—but the government requires meat packers to maintain records of frozen beef shipments for only two years.

But it's unlikely that you'd find such old meat on your plate. Ice crystals form on meat that's been left in the freezer too long, breaking down the cell structure of the muscular tissue and making it soggy. This decrement in quality is so obvious that very few restaurants would bother serving it. Since none of the frozen meat produced by Hallmark was sold directly to grocery stores, consumers don't have to worry about any contaminated packages tucked away in their home refrigerators. Most of the beef in question was sold directly to the food-service industry and to school lunch programs, which don't normally keep supplies sitting around for years on end. (For more detail, read this Explainer from 2008.)

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Juliet Lapidos is a staff editor at the New York Times.