Concern about foodborne disease has been heightened in recent years due to a spate of deadly outbreaks at restaurants, fast food outlets and county fairs. The U.S. Centers for Disease Control and Prevention (CDC) estimates that 33 million people suffer from foodborne disease each year, nine-thousand of whom die.

Research has shown that irradiation destroys at least 99.9 percent of common foodborne pathogens such as Salmonella, E. coli O157:H7, Listeria monocytogenes and Campylobacter jenuni. Based on such findings, the U.S. Food and Drug Administration (FDA), USDA and the World Health Organization (WHO) have advocated the use of food irradiation to reduce the levels of foodborne pathogens in food supplies. Many health experts agree that using a process called irradiation can be an effective way to help reduce food-borne hazards and ensure that harmful organisms are not in the foods we buy. Irradiation, a process in which foods are exposed briefly to a radiant energy source, also can prolong the shelf life of fruits and vegetables by reducing spoilage bacteria and mold, while inhibiting sprouting and maturation.

How it works

Irradiation works by disrupting the organic processes essential to life. The energy waves break the molecular bonds inside the genetic materials of pathogens, insects and organisms that cause foods to spoil. The bombardment kills or renders the organism unable to multiply. However, viruses and prions are generally resistant to irradiation.

There are three different irradiation technologies used with foods: gamma rays, electron beams and X-rays. Gamma ray irradiation utilizes Cobalt 60 or Cesium 137 to penetrate foods to the depth of several feet. The radioactive element is stored immersed in water within a concrete chamber. Food is brought into the room and the element is lifted from the water to administer the proper radiation.

Electron beams and X-rays work along the same principles but are easier to administer because they can be switched on and off. Electron beams emit a stream of high-energy electrons, propelled out of an electron gun directly at the food, penetrating a few centimeters. X-ray radiation uses an X-ray machine that is a more powerful version of the machines used to take X-rays in hospitals.

History

Though a majority of Americans are unaware of food irradiation, it has actually been studied as a way to improve food products since the 1930s and has been used for nearly 40 years. In 1963, the federal government granted permission to irradiate wheat and wheat flour to kill insects in the wheat. Irradiation was first approved as a method for controlling foodborne pathogens among spices and dried vegetable seasonings in 1983.

Irradiation for pathogen control was extended to dry enzymes in 1985, raw pork in 1986, raw poultry in 1992, refrigerated and frozen uncooked beef, lamb, goat and pork in February 2000 and fresh egg shells in July 2000. The FDA and USDA are currently considering whether to allow the irradiation of precooked meat products such as hot dogs.

Regulatory Control

Numerous federal agencies have regulatory responsibilities regarding food irradiation. FDA plays the primary role in ensuring the safety of irradiated food. The FDA's Bureau of Food Irradiated Foods Committee conducts toxicological analyses and assesses the safety of various irradiated foods.

USDA, the Nuclear Regulatory Commission and the Occupational Safety and Health Administration also help to regulate the types of foods that can be irradiated, the proper use of the irradiation process, the safety of workers in facilities and transportation of radioactive material. The Food Safety and Inspection Service of the USDA monitors the irradiation process in accordance with a Hazard Analysis and Critical Control Point plan, a science-based process control system designed to improve the safety of meat and poultry products.

Both FDA and USDA require irradiated food products to be labeled with a statement conveying that the product has been intentionally subjected to radiation as well as the international food irradiation symbol - the radura.

Opposition to irradiation

Though each of the government entities responsible for protecting the food supply have endorsed the use of food irradiation, a number of activist groups contend that irradiation produces unknown compounds in foods that could cause cancer or other diseases. Additionally, opponents argue that irradiation dramatic decreases vitamin levels in foods.

According to the WHO, "Food irradiation is perhaps the most thoroughly investigated food processing technology." An expert committee convened by the WHO reviewed the findings of more than 500 studies and concluded that there are no toxicological, microbiological or nutritional problems associated with irradiation.

The US General Accounting Office concurs, finding, "The cumulative evidence from over four decades of research - carried out in laboratories in the United States, Europe, and other countries worldwide - indicates that irradiated food is safe to eat." Further, George Pauli, the leading irradiation expert for the FDA, notes that these studies have "never [shown] a link with carcinogenicity or other toxicity."

Future of irradiation

In the past five years, the percentage of dried spices and seasonings irradiated has increased from 2.5 percent to 22.5 percent. Indeed, as of January 2000, spices and seasonings account for 95 million of the 97 million pounds of food products that are irradiated annually in the US. The approval of irradiation for use with red meats should increase these figures.

Still, retail outlets have been slow to carry irradiated foods because many store owners and food producers fear that misgivings about radiation in general will prevent consumers from trusting irradiated products. A recent FDA survey found that more than half of consumers have never heard of food irradiation. Such statistics have led the USDA to conclude that, "Accurate public information about food irradiation may well determine whether more consumers become willing to buy…irradiated food products."

Food Marketing Institute studies demonstrate that consumers will accept irradiation if they are properly informed about it. When science-based information about irradiation was presented to consumers, the willingness to buy irradiated foods increased from 50 percent to 90 percent.

The costs of irradiation

Beyond the challenges of consumer education, the question of whether consumers will pay the additional cost for irradiated food remains. Indeed, prospective costs have deterred many food manufacturers from investing in the technology. Capital costs for radiation systems range from $4.4 to 17.0 million. Additionally, studies have estimated that it would cost between 0.5 to 2.0 cents per pound to irradiate food. Such additional expenditures would likely be passed onto consumers at the rate of two to five cents per pound.

Proponents of irradiation contend that these costs would be offset by a decrease in foodborne illness and corresponding legal and punitive claims. According to the Economic Research Service of the US Department of Agriculture (USDA), "Properly operated irradiation units will reduce or eliminate the risk of pathogen contamination of food products and the possible adverse consequences for firms, including voluntary and mandatory product recalls, fines and other penalties for violating food safety regulations, litigation and damage awards resulting from foodborne illness, and the loss of business reputation and sales associated with unfavorable media attention."

Multiple barrier approach

Though food irradiation shows great promise in helping to reduce incidence of foodborne disease, it is merely one layer of protection in a multi-barrier regiment of food safety. According to Terry Roberts, former head of Microbiology at the Reading Laboratory's Institute of Food Research, it is also important to "follow good personal hygiene and sanitation practices and to handle the processed foods appropriately during distribution." The Food Safety and Inspection Service concurs, saying that "irradiation does not replace sanitation systems; it is an additional tool to ensure safe, wholesome food products."

The combined efforts of irradiation, sanitation and disease prevention hold great promise in providing added protection to the world's food supply, thereby reducing the incidence of foodborne disease.

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