Gamma Burgers
I pretty much ignored the
first reports this summer that people were getting food poisoning from E. coli
O157:H7 bacteria in hamburgers. I might have raised an eyebrow when beef
supplier Hudson Foods recalled 25 million pounds of hamburger. But when the
recall caused Burger King to run out of burgers, I started to worry. Shouldn't
somebody do something about this food poisoning thing?
The Big Media apparently
agreed. Within days of the recall, the New York Times , the Wall
Street Journal , Newsweek , and others were proposing a simple
solution: Irradiation of food to kill not just E. coli but all the nasty germs
and parasites that slip into our food supply.
This
rapid blanket approval of irradiation by the establishment naturally stirred my
suspicions. We are talking about radioactivity, after all. On closer
inspection, however, food irradiation turns out to work safely and effectively,
opponents' concerns notwithstanding. But questions remain about whether food
poisoning is such a big problem in the first place.
Human skin and intestines crawl with ordinary E. coli. But
a few uncommon strains of the bacteria--especially the notorious E. coli
O157:H7--produce toxins. Ingest these toxic bacteria, and you experience watery
diarrhea and severe abdominal pain at first, bloody stools next. You're
miserable, but these symptoms don't usually require medical attention--at
least, in developed countries. But in some cases, the toxins trigger the
destruction of blood cells and cause renal failure. This "hemolytic uremic
syndrome" can be deadly in children. The Centers for Disease Control estimate
that toxic E. coli cause 25,000 cases of illness and up to 100 deaths each year
in the United States.
Meat is
the most common source of E. coli O157:H7, but raw milk, vegetables, and fruit
juice have carried it in recent outbreaks. (You may recall that toxic E. coli
showed up in alfalfa sprouts two months ago, and in Odwalla apple juice last
year.) The bug lives in the guts of about 1 percent of cattle and contaminates
meat when digestive contents spill where they shouldn't during slaughter. It
also contaminates produce if farm waste-water enters the irrigation supply.
Toxic E. coli are just one of the top seven bacterial food contaminants. More
common bacteria, such as salmonella (present in 60 percent of chicken) and
campylobacter (the number one cause of food poisoning), cause diarrhea for 2
million to 4 million Americans each year. However, washing your produce and
cooking your meat until well done will almost always remove these bacteria.
Burger King terminated its Hudson Foods supply
contract not for safety concerns but for PR reasons. Like other fast-food
chains, it cooks its burgers to over 155 degrees, killing all bacteria. But it
feared that it might earn a reputation for bacteria burgers, which has plagued
the Jack in the Box chain ever since 1992, when four people ate some of its
undercooked, tainted beef and died. (Ironically, Hudson Foods, primarily
chicken suppliers, didn't distribute beef until Burger King talked them into
the business a few years ago.)
Advocates
of food irradiation say that a rare burger doesn't have to be dangerous.
Irradiators containing cobalt-60 or another radioactive source would bombard
hamburger, apple juice, and other foods with gamma rays, killing resident
bacteria and parasites. The radiation disrupts DNA, which germs need to
survive. (Meat doesn't need functional DNA, since it's already dead.) Lower
doses will pasteurize food--i.e., kill the disease-causing organisms. Higher
doses of radiation will completely sterilize food.
Supporters of irradiation like writer Richard Rhodes argue
that the process is perfectly safe, leaves no funny taste or appearance, and
prevents illness from E. coli O157:H7, salmonella, beef tapeworms, fish
parasites, and trichinae in pork. Since fungi are killed, radiation-pasteurized
food lasts longer, too--up to two weeks in the fridge instead of a few days.
For gamma ray fans, food irradiation is the most logical step after heat
pasteurization of milk.
The Food
and Drug Administration has approved irradiation of produce, pork, poultry, and
other foods, but industry has not adopted it widely. (For unclear reasons, the
FDA has stalled on a 1994 application to allow the industry to irradiate beef
and veal.) You'd think that the poultry industry, which has suffered terrible
publicity over salmonella outbreaks, would rush to irradiation, but it fears
that the negative public reaction to irradiation would be worse. Currently,
astronauts, patients in many hospitals, and people in 27 other countries eat
irradiated food.
Advocates blame slow adoption of irradiation on
technophobic lobbying groups that ignore the evidence and stir public fears
with outrageous claims that the process makes food radioactive. The critics I
spoke to, however, offered credible arguments. Most admit that irradiation
works, and some, like Michael Jacobson of the Center for Science in the Public
Interest, will even concede it's safe for consumers. But they argue that it's
expensive, harmful to workers and the environment, and unnecessary if safer
farming methods are practiced. They suggest growing livestock under cleaner,
less confined conditions to prevent contamination of feed and water;
slaughtering the animals so bacteria-containing skin and feces never get on
food; and using simpler technologies, like steaming, to clean raw meat. As
environmental advocate Michael Colby told reporters, "Irradiation is a cop-out.
Irradiation is saying we have to have fecal matter in our hamburgers."
For the
record, gamma rays do not make food radioactive. And studies do seem to show
it's safe. In a six-year study, scientists fed dogs and other animals
irradiated chicken and found no evidence of increased cancer or other toxic
effects. Other research found no signs of hazard in humans who eat irradiated
food. Also, studies showed that, at the lower, pasteurization doses, radiation
does not degrade nutrients. The World Health Organization, the American Medical
Association, and the American Dietetic Association all back the technology as
safe.
What about the other arguments against irradiation? It
doesn't seem expensive--they use it in Bangladesh, after all. A Florida company
charges 4 cents a pound for irradiation, and advocates say wider use would
halve costs. The risks to the environment and to workers seem theoretical. The
same technology is already used safely in hospital radiation-therapy units and
plants that sterilize medical products. Food irradiators do produce radioactive
waste that must be stored under nuclear regulatory guidelines, but the current
regulations governing hospitals and sterilization companies seem to work, and
the amount of radwaste generated is far too small to cause Three Mile
Island-like effects. Advocates like to point out that the waste hasn't killed
anyone, but kids die every year from food poisoning.
Irradiation also seems more cost-effective than changing farming and
slaughtering practices. It's pretty hard to keep feces out of meat. Some meat
producers in Sweden do, but their meat is double or even triple the usual
price. And even with clean practices and technologies like steaming of meat
(which hasn't been tested nearly as much), some food would still be
contaminated. Advocates say there'd still be reason to irradiate.
So irradiating food seems safe, effective, and
cheap. Yet it also seems like a high-tech swatter for an overhyped fly. Toxic
E. coli infect just three in 100,000 people. Thanks to officials who pushed for
a recall, Hudson hamburgers didn't kill anyone. Irradiation backers exaggerate
food poisoning's impact, claiming the top seven contaminants kill 9,000 people
each year. According to the most recent data, though, fewer than 1,000 people
die from tainted food each year. Compare that with, say, car accidents, which
kill 40,000 people a year, or smoking, which kills over 400,000.
Food poisoning is a serious
risk only for vulnerable populations, like the very young. For the rest of us,
it's an uncommon annoyance caused mainly by inadequately cooked chicken or
pork. I'm not against saving a few hundred lives a year for a few pennies extra
on my beef, so go ahead and zap my food. But irradiated or not, I'll still
order my burgers rare.
