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Most of the heat and radioactivity from spent nuclear fuel dissipates within 50 years. For more information, see: For a lesson about this topic, see: |
Bacterial infection or infestations can cause food to spoil, make us sick, and even lead to death. Because of this, scientists from the food industry and government are continually searching for effective methods to reduce spoilage and make food safer, while keeping it wholesome for us to eat. In Canada, it is estimated that more than 2,000,000 cases of food-borne illness occur each year. Health Canada estimates that about 760,000 cases of salmonella occur each year in Canada which on average result in approximately 760 deaths. The World Health Organization estimates that in developing countries six children die every minute from diarrhoea, partly because of food poisoning or bad drinking water.
Aside from the human costs, the costs due to hospital visits, time lost at work and wasted food run into the billions of dollars each year. The United Nations Food and Agricultural Organization Committee on Food Safety reported that one-quarter to one-third of world food production is lost due to pests, insects, bacteria, fungi and enzymes which degrade or destroy crops.
Long ago people learned to preserve food by drying, salting or pickling in vinegar. Today we have modern packaging, canning, refrigeration and freezing facilities as well as a modern transportation system to process and deliver food. Many developing countries however, lack modern food processing and preserving facilities resulting in a far greater number of food-borne illnesses.
Food irradiation is a process — not an additive — that helps to preserve food by killing bacteria, fungi, parasites and insects, by using ionizing radiation. This process not only kills these agents; it also extends the shelf life of food because there are very few bacteria remaining to aid in the decay process.
Food irradiation is a cold, non-chemical process that can virtually eliminate harmful bacteria such as e. coli O157:H7 from ground beef, Salmonella and Campylobacter from poultry, and Listeria monocytogenes from hot dogs and luncheon meats. Food radiation techniques now make it possible to treat such packaged or bulk foods with no significant change in taste or nutritional value.
Canada has conducted scientific research in the field of food irradiation since the 1950s, and the Canadian firm MDS Nordion has built many of the food irradiation installations around the world.
Worldwide, there are many countries where foods are approved for irradiation. In Canada, whole wheat has been treated using this process since the 1960s. Other foods approved for irradiation in Canada include: flour, herbs and spices to kill insect pests while potatoes and onions can be irradiated to reduce sprouting.
Food irradiation can:
- Extend shelf life of food by destroying the microorganisms that cause spoilage.
- Make food safe to eat by destroying parasites and microorganisms that cause trichinosis and salmonella poisoning.
- Provide quarantine treatments for fruits and vegetables to ensure insect pests are not transported across borders.
- Prolong the shelf life of foods by slowing the ripening process and inhibiting the sprouting of root vegetables like potatoes and onions.
Many studies have been conducted since the late 1940s to evaluate the nutritional value of irradiated foods and to determine the safety of the process. The treatment process can be designed and controlled so that the above benefits can be realized safely without any significant reduction in the nutritional value of the food.
How is Food Irradiated?Food is irradiated similarly to the way luggage is x-rayed at airports. The food is passed through a thick-walled chamber containing a source of ionizing radiation that passes through the food, destroying insects, bacteria and microorganisms. Many irradiators use cobalt-60 as the source of radiation. Cobalt-60, a man-made radioisotope, is a radioactive isotope produced in CANDU reactors in Ontario and Quebec. It has a wide range of medical, consumer and industrial uses.
There are more than 170 gamma irradiators worldwide.
Is Irradiated Food Radioactive?No. Just as a dental x-ray does not make you radioactive, irradiated food is not radioactive. The World Health Organization, the United Nations Food and Agricultural Organization, and the International Atomic Energy Agency have reviewed accumulated data from more than 40 years of research. They found that irradiated food is as safe as food preserved with other techniques like freezing or canning.
The nutritional value of irradiated food was also found to be as good as food treated by these other processes.
Food irradiation has been studied and tested more extensively than any other food preparation or preservation process. Decades of testing using the most recent methods in toxicology have proven that foods treated with appropriate levels of ionizing energy do not have adverse effects on the consumer. As of the year 2000, 40 countries had approved over 50 different foods.
Where is Food Irradiation Used Now?
Today, food is irradiated in many countries around the world. In France and the Netherlands, large quantities of seafood, vegetables, fish, and frogs' legs are irradiated. Other countries actively involved in food irradiation include Brazil, Mexico, Japan, Belgium and Israel. In the United States, irradiated hamburger patties are sold in every state. Papayas are irradiated in Hawaii and imported to the mainland.
The International Atomic Energy Agency estimated that in 1995 more than 500,000 metric tonnes of food was irradiated throughout the world.
A substantial portion of the spices used in Canada are irradiated. Health Canada is studying requests to apply the process to poultry and red meat.
Food irradiation is a process that can make food safer by eliminating insects, bacteria and other microorganisms. It offers advantages over other conventional processing and additive techniques. Like pasteurization, irradiation can help ensure that our food remains wholesome and safe to eat. Properly labelled, irradiated food permits a better choice for the discriminating Canadian consumer.
Resources:
CBC Market Place
www.cbc.ca/consumers/market/files/food/irradiation/canada.html
Health Canada Food and Nutrition
www.hc-sc.gc.ca/fn-an/securit/irridation/index_e.html
Canadian Food Inspection Agency
www.inspection.gc.ca/english/fssa/concen/tipcon/irrade.shtml
Canadian Nuclear Association. Nuclear Facts — Why Food Irradiation?, www.cna.ca/english/pdf/NuclearFacts/17-NuclearFacts-foodirradiation.pdf