The Dangers Of Food Irradiation Biology Essay

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Food irradiation is a process by which certain foods are exposed to gamma radiation in order to control insects, pests, bacteria, and other food-borne pathological organisms. Food irradiation also prolongs the shelf life of certain foods. However, the process causes changes in food structure, taste, smell, texture, and color, as well as changes in nutrient content. It has also been linked to cancer and the production of carcinogenic compounds called 2-alkylcyclobutanones (2-ACBs). In spite of the overwhelming evidence to the contrary, organizations such as the U.S. Food and Drug Administration (FDA), the World Health Organization (WHO), and the Food and Agricultural Organization of the United Nations (FAO) have deemed the process safe and endorsed and/ or approved of the irradiation of foods such as herbs and spices, grains, fresh fruits and vegetables, juices, eggs, and meats and poultry. Despite the assurances of these organizations that food irradiation is not dangerous, the concept has yet to gain wide spread acceptance and consumers remain wary of the health risks eating these foods may result in.

Scientists have engaged in the practice of irradiating food since the early 1900's1. Though not an overly complicated procedure, in order to fully understand the dangers of ionizing radiation on food products, it is important to understand key components of the process through which irradiation is achieved, as well as the hazards associated with the sources of radiation most commonly used during the ionization process. Once the foods destined for irradiation are processed and packaged according to the Codex Alimentarius'2 standards, most methods of irradiation take about thirty minutes to complete. They are placed into large metal boxes where they are transported across radiation sources via conveyor belts3 and exposed. As the packages cross the radiation source, they are exposed to radiation said to be equivalent to 30 million x-rays (LaForge, 2000). The gamma rays or high energy electrons pass through the packaged food, effectively controlling spoilage bacteria, insects and pests, and other food-borne, pathological organisms, yet the procedure does not leave the food radioactive. This is because in order to create radioactive foods, the exposure to radiation would have to be powerful enough to interact on a molecular level with the nucleus of the food's molecules. However, this does not suggest that the food which has been irradiated remains unchanged and as it was prior to exposure. From there, the irradiated food is shipped nationally to be purchased by consumers.

Sources of radiation

Food irradiation by and large uses gamma ray sources such as radioactive cobalt-60 and cesium-137, however, high energy electron beams, also known as e-beams, may also be utilized to carry out the task. Although the latter source does not use radioactive materials, the process is only able to penetrate foods up to three centimeters or just over an inch thick; foods twice as thick may also be irradiated using opposing beam technology (UWFIEG, 2010). The average cost of a food irradiation facility ranges from roughly $1 million to about $5 million, with average e-beam facilities costing approximately $2 million (Andress & Delapane, 2010). Therefore, using this technology for large scale food irradiation is an extremely expensive procedure, not cost effective, and is consequently rarely ever used.

Cobalt-60 is one of two food irradiation sources that emit large amounts of gamma radiation. According to the Centers for Disease Control (CDC), Cobalt-60 is an extremely hazardous compound. Persons exposed to the material may experience severe radiation burns, also known as erythemia, acute radiation sickness, and even death (2010). When processed, it can also be found in powdered form. This increases the danger of exposure to the public because in this state, the particles may become airborne, possibly contaminating local water supplies and fertile agricultural farmland. As a precaution, when not in use, irradiation facilities lower the radioactive compound into cooling pools. This practice is, in and of itself, hazardous: In their article The Dangers of Irradiation Facilities, Public Citizen, a non-profit environmental group based out of Washington D.C., describes some of the many accidents experienced by irradiation facilities:

"In 1974, the radiation director at an Isomedix cobalt-60 facility in northern New Jersey was exposed to a near-fatal dose of 400 rems while irradiating medical supplies. The man was critically injured and hospitalized for a month. Two years later, a fire near the cobalt storage pool released chemicals into the pool that caused the cobalt rods to corrode and leak. Radioactive water was flushed down the toilet into the public sewer system. The amount of radiation released into the public sewer system was never determined" (2010).

Another story, this one from an irradiation plant in Israel, provides perspective and demonstrates just how dangerous this substance can be:

"In 1990, a worker at a cobalt-60 facility in Soreq entered the radiation chamber after an alarm sounded. Acting contrary to operating and safety instructions, he did not notify his supervisor and instead handled the situation on his own. He turned off the alarm, bypassed the safety system, unlocked the door and entered the chamber. He did not notice that the cobalt-60 was exposed until he moved a pile of boxes. After a minute of direct exposure, he began to feel a burning sensation in his eyes and left the room. He died 36 days later" (2010).

Transportation of radioactive substances to and from irradiation facilities is also a matter of contention. Most of the Cobalt-60 manufactured for the purpose of food irradiation is produced by Nordion International Inc. out of Canada. It is then transported to the U.S. for use in irradiation plants nationwide. Although precautions are taken to avoid accidents, as the distance traveled by transport vehicles raises, so does the probability of mishaps occurring.

Cesium-137 is the most common radiation source of food irradiation facilities because it is the only isotope produced in quantities large enough to support irradiation of large amounts of food on a regular basis. It is also, arguably, the most dangerous of the three radiation sources for several reasons. First, unlike Cobalt-60 which is a metal, in its natural state, pure Cesium-137 takes on a liquid form. (CDC, 2010). This means that unlike the metallic isotope which contaminates by exposure, if ever there was an accident, the isotope has the ability to effortlessly blend into the environment, mixing with local water supplies, seeping into the earth and/ or concrete structures with the potential of affecting thousands of people. Because it also readily mixes with chlorides, it more commonly occurs in powder form forming a powder making the possibility of airborne contamination extremely likely in the event of an accident (CDC, 2010). Secondly, Cesium-137 is a byproduct of nuclear weapons production and can still be detected in the air as a result of fallout from nuclear weapons testing from the 1950's and the well known disaster at the Chernobyl Nuclear Power Plant in 1986 (CDC, 2010). It has a half life of about 31 years making it deadly, depending on the quantity, for up to 600 years (LaForge, 2004). The third and most threatening danger of Cesium-137 comes, not from the isotope itself, but from the people regulating the use of the radioactive material. In his article for Z Magazine, John M. LaForge quotes representatives of The Department of Energy admitting to the House Armed Services Committee in 1983 that: "The utilization of these radioactive materials simply reduces our waste handling problem…we get some of these very hot elements like cesium and strontium out of the waste". He goes on to quote FDA spokesman Jim Greene in 1986 stating that using the cesium-137 "could substantially reduce the cost of disposing of nuclear waste" (LaForge, 2004). In addition to these reasons, Cesium-137 also shares the fears associated with transportation that Cobalt-60 does.

Effects of irradiation on food

The benefits of food irradiation have been well established. The process prevents sprouting and delays ripening, significantly reduces and/ or destroys harmful bacteria such as spoilage bacteria, E. coli, and Salmonella, and kills insects and other harmful pests that infest wheat and other dried goods and spices.4 However, irradiation also has a negative impact on food that is rarely discussed. The practice, which uses ionizing radiation, also changes the natural state of the food, resulting in loss of color, changes in taste and texture, and even producing what has been termed an "off odor" in certain products. For example, in his research, X. Fan discovered that doses as low as 0.7 kGy alter the taste of orange juice, giving it a "plastic to decayed" flavor, rendering the juice "unpalatable" (2004). "Irradiation of eggs gives them a more watery consistency and makes them have less color than non-irradiated eggs" (, 2009). In an article meant to support food irradiation as a means of promoting food safety, the author, P.J.Skerret, admits that radiation "kills or at least alters living cells" and that "some foods such as cucumbers, grapes, and some tomatoes turn mushy when radiation breaks cell walls…" (Skerrett, 2000). At higher doses, the production of sulfur compounds in fresh orange juice was discovered, causing an "off-odor" smell along with the production of a toxic chemical called 2-butanone (Fan, 2004).

To clarify, radiation exposure produces ions and free radicals that interact with food on a molecular and even atomic level producing chemicals called 2-alkylcyclobutanones or 2-ACBs. This chemical, as well as all members of the butanone family have been given the broader designation of unique radiolytic products or URPs. They are so named because they do not occur naturally in any food, and only occur in food products exposed to radiation. In their online column, The Issues, states that these chemicals have been linked to cancer in rats, and have been known to cause genetic damage in human cells (2009). In addition, studies of foods exposed to radiation show that there is an increase in toxic chemicals such as benzene, toluene, and methyl ethyl ketone; all which have been associated with cancer and birth defects (Public Citizen, 2002).

The nutrient content of these foods is also affected. In eggs, radiation exposure destroys vitamin B3, also known as niacin, and vitamin A, reducing quantities by as much as 24 percent (, 2009). In another study, X Fan, along with K.J.B. Sokorai, claims that exposure of green and red-leafed lettuce to 1 kGy of radiation resulted in lowered vitamin C contents by 24% - 53% when compared to control subjects (Fan & Sokorai, 2008). Other vitamins such as C, E, and K may experience drops from 5% - 25% in irradiated food (LaForge, 2004).


Though the topic is much too broad to discuss in one paper, there are many other concerns revolving around this industry that should be explored and answers to questions that should be sought. What steps are being taken to ensure the safety of irradiated foods after exposure? Though the process virtually eliminates microorganisms, it does not do anything to rectify the filthy conditions found in many slaughterhouses. Animal excrement and waste is teeming with infectious organisms, providing ample opportunity for recontamination. Further research should also be conducted in order to determine the long term affects of consuming irradiated food products. The approval process should also be reexamined. Even if one completely supports the process of food irradiation, there is enough evidence to warrant a closer examination of the practices and procedures of food irradiation plants, as well as the effects of radiation exposure on food. Without proper and thorough research, it is only a matter of time before change is spurred at the expense of an epidemic or death due to radiation exposure.