Sustainable Wellington Net—Food Irradiation Campaign

Apart from the coloured annotations this fact sheet appears "as is". An electronic copy of the original is available from ANZFA, MAF, or the Ministry of Health

Food Irradiation Fact Sheet

What is food irradiation?

Food irradiation involves treating certain types of food with ionising energy or radiation. It is used to destroy bacteria and parasites that cause human illnesses. It can also make food last longer by: destroying or inactivating insects, moulds and yeast that spoil food; delaying the ripening of fruit and vegetables; and limiting unwanted sprouting of potatoes and other similar vegetables.

Different doses of ionising radiation have different effects. At low doses, irradiation lengthens the shelf-life of certain foods such as strawberries and prevents sprouting of potatoes. At higher doses, irradiation helps reduce amounts of harmful bacteria on foods such as dried herbs and spices and chicken.

Food irradiation is another way of preserving food to keep it safe and wholesome, similar to pasteurisation and freezing.

What is New Zealand's existing policy on food irradiation?

In 1989 the Government published a Policy Statement that irradiation processing of food for human consumption will not be permitted in New Zealand. The Food Regulations 1984 also prohibit the sale of food treated by irradiation unless specific permission for use of the treatment has been granted by the Minister of Health.

In contrast, many countries in the world permit the treatment of some foods using irradiation following a case-by-case consideration.

Are irradiated foods safe and wholesome?

Over 50 years of research shows that even foods exposed to high doses of irradiation are safe, wholesome and nutritionally adequate. The safety and nutritional adequacy of irradiated foods has been more intensively studied than any other food processing method. Research indicates it is as safe as any other conventional processes such as canning, freezing and pasteurisation, provided that good manufacturing procedures are followed.

ME: The 50 years of research presumably includes research carried out by the US Army in the 1950s and 1960s which was used to obtain the clearance for irradiated bacon in 1963 - this clearance was subsequently withdrawn in 1968 when the FDA found the research data badly flawed

It presumably also includes subsequent research done in the US by Industrial Bio-Test Ltd (IBT). Three directors of IBT were convicted in 1983 for conducting fraudulent research for the government and industry. IBT's work was described as being characterised by "missing records, unallowable departures from testing protocol, poor quality work, and incomplete disclosure of information on the progress of the studies"

There are large areas of scientific uncertainty regarding the safety of foods which have been irradiated. In the process of irradiation the molecular structure of food is affected, what are termed "unique radiolytic products" (URPs) are created¹. There is uncertainty about the effects on humans of the consumption (particularly long term) of these URPs, but there are disturbing indications from studies:

Lethal effects have been found from the feeding of irradiated food to mice (though other studies failed to confirm this)
Some animals fed irradiated food have been found to have reduced growth, changes to white blood cells, and kidney damage
Two studies in the US raised questions about the safety of irradiated chicken
Polyploidy - a chromosome defect - has been observed in children, monkeys, rats fed irradiated wheat, and in hamsters fed an irradiated diet²

In the early 1980s when the FDA reviewed over 2,000 studies of food irradiation, they found only 441 of these of sufficient standard to justify further review. Of these 441 they found only five were "properly conducted, fully adequate by 1980 toxicological standards, and able to stand alone in support of safety". Despite the shaky basis of just 5 studies the FDA approved the use of irradiation of food. These 5 studies have subsequently been strongly criticised as being seriously flawed in their methodologies and interpretation of data³

Are the results of just 5 studies, results which have been seriously challenged, sufficient basis to make the statement that "even foods exposed to high doses of irradiation are safe"? Serious questions remain about the safety of irradiated food

Three international agencies: the World Health Organisation and the Food and Agricultural Organisation of the United Nations, and the International Atomic Energy Agency accept the safety and usefulness of food irradiation. The process is also endorsed by the American Medical Association, the Scientific Committee of the European Union, and the American Spice Trade Association among others.

Overseas, at least 40 countries have been granted clearances or authorisations to irradiate specific foods. The way regulations are administered result in differences in these countries as to whether final authorisations and specific regulations have been put in place. Countries that irradiate food commercially in small volumes include Belgium, China, France, the Netherlands, South Africa and the United States. Another 10-15 countries occasionally irradiate small food batches for research and market testing purposes.

The overwhelming consensus of the scientific community is that irradiation produces safe and nutritious food when carried out in accordance with specified standards.

DL: Irradiation can reduce vitamin and nutrient content. It depends on the food, the irradiation process, and the temperature. Irradiated foods may show accelerated vitamin loss during storage or further processing (e.g. cooking). Recommendation - Every irradiated food should be tested by an independent laboratory for nutrient loss

The issue of genetic (chromosomal) damage to those eating irradiated foods has not been settled. Irradiated foods should not be permitted until the industry funds an independent 4 month study of the effect of irradiated foods on chromosomes. It should be a diverse study group - young/old, more affluent/less affluent, men/women, whites/blacks. The study would probably be negative but it must be done

Food irradiation - how does it work?

Food is irradiated by exposing it to a source of ionising radiation. The ionising radiation usually is in the form of gamma rays from a source of cobalt-60, or from a non-radioactive source (electron beam) generated from electricity. Electron beam technology does not require the use of radioactive source material, and can be "turned on and off". The gamma rays are similar to ultraviolet light or microwaves, but of much shorter wavelength and greater energy. Gamma rays pass energy through food in the same way microwaves pass through food, but in this case the food remains cool.

The radiation damages the genetic material of the contaminating organisms so that they can no longer survive or multiply. Like pasteurisation, it can make the food safer to eat by destroying bacteria. Unlike pasteurisation, it can be used on solids as well as liquids.

Does irradiation cause the food to become radioactive?

The food does not become radioactive for two reasons. First, the gamma rays from cobalt-60 used in food irradiation are not energetic enough to make foods radioactive. Second, as the food never comes into direct contact with the source, it is not possible for the food to become contaminated with the radioactive material.

What are its limitations?

You cannot successfully freeze or can all types of food. Similarly, not all types of food can be treated with ionising radiation. For example, many dairy products treated with ionising radiation develop objectionable changes in flavour, odour and colour, even at low doses. Whole eggs are another product that may not be successfully treated.

Food irradiation is not a substitute for proper food handling and cannot enhance food that is deteriorated, contaminated or of inferior quality, or prevent contamination from improper handling after irradiation. Irradiation is an option as part of a total system to improve food hygiene throughout the food processing and handling chain.

Do we need it?

Irradiation of foods may help reduce the incidence of food borne disease. It could also help prevent insect pests entering or leaving the country on certain foodstuffs, and it would be an alternative to some chemical treatments of food.

In many countries, including New Zealand, an increasing number of people are becoming sick from food borne diseases caused by micro-organisms like Campylobacter and Listeria. Food borne illnesses can be serious and in rare cases cause death. Food irradiation is one safe and effective tool to help combat this pressing public health problem related to our food supply.

Some foods, such as spices and uncooked chicken, can occasionally carry a high risk of bacterial contamination. For dried herbs and spices, there are very few treatment methods that can be used without loss of quality or flavour. Spices are currently treated with ethylene oxide gas to rid them of potentially harmful bacteria. Food irradiation may be an alternative to chemical treatments such as ethylene oxide.

ME: This section is again misleading. The irradiation of imported food is not going to have any significant effect on the rate of food poisoning in New Zealand. Further irradiation at the proposed levels does not kill all bacteria, it also does not destroy the toxins created by the bacteria in the early stages of contamination. Irradiation also kills beneficial bacteria which produce odours indicating spoilage and naturally control the growth of harmful bacteria. There is evidence that irradiation stimulates aflatoxin production. This is a toxin that occurs in fungus spores on grains and vegetables in humid and tropical countries

There is concern that irradiation will likely have a mutegenic effect on bacteria producing resistant strains

Irradiation is not the only alternative to chemicals such as ethylene oxide. Dr Ross Lill of The NZ Institute for Crop & Food Research stated that "he remains to be convinced that irradiation is the quarantine answer to eliminating insects, pests, and diseases from food safely"⁵. There are alternatives such as steam treatment, ozone⁶, and the use of controlled atmospheres with high concentrations of CO₂

In short irradiation is not a benign "silver bullet" and we do not need it

Why is food irradiation important to our export/import markets?

New Zealand and many of its export markets guard against the importation of exotic insect pests by requiring a post-harvest disinfestation treatment of commodities that can carry pests (e.g. some fresh fruits, vegetables, nuts, cereals and grains). Methyl bromide is the most widely used quarantine treatment. New Zealand and many other countries have undertaken to phase out the use of methyl bromide, an ozone-depleting gas, by 2005, but exemptions exist for quarantine and critical use procedures.

Irradiation can be also be used for the disinfestation/disinfection of pests and disease-causing organisms from a range of products, including some fruits and vegetables. In specific instances, food irradiation may be an alternative to methyl bromide and other post-harvest treatments.

Without the ability to permit the sale of irradiated foods, New Zealand could continue to be dependent on chemical alternatives to safeguard certain foods while other countries are phasing out or banning the use of these chemicals. Further, since there is overwhelming scientific consensus on the safety of foods irradiated to specified standards, a prohibitive policy would be very difficult to justify on technical grounds and could be challenged under the World Trade Organisation as a technical barrier to trade.

Can irradiated foods be distinguished from other foods?

The consumer would not be able to detect that a food has been irradiated. Irradiation produces small changes in food, but generally the constituents of irradiated foods are not unique and cannot be distinguished from those in other foods, either non-irradiated or processed by other methods. However, tests are now available to detect irradiated foods in most situations. It may not always be possible to detect an irradiated ingredient when it is a minor food component of a larger food product or if, for example, an irradiated spice is blended with a large volume of non-irradiated spice.

How will I know what foods have been treated with irradiation?

Labelling is one of the issues being considered in a new draft food standard by the Australia and New Zealand Food Authority. The draft standard for food irradiation proposes that foods containing irradiated ingredients or components must say so on the label. Most other countries that permit food irradiation require labelling.

Will we still be nuclear free?

Radiation technology is already used in medical diagnoses and treatment through the use of x-rays, and nuclear medicine. It is commonly used in the treatment of cancer. Radiation technology is also used in a variety of detection and measurement instruments in industry (including the food and bottling industries). None of these uses affects New Zealand's nuclear-free stance - nor would irradiation of food.

The draft standard proposes to prohibit the irradiation of food, or ingredients or components of food, unless specific permission is given. As New Zealand retailers will be able to import and sell foods irradiated overseas as specified under the standard, there may be no increase in the number of radiation facilities in this country. If local food processors decided to apply the technology here, then, depending upon the particular use, they may be able to choose a non-radioactive (electron beam) source of irradiation.

Any consideration of the building of new food irradiation plants would be subject to other legislation including the Resource Management Act 1991 and the Radiation Protection Act 1965.

Further Comments

There are real problems of monitoring and verification which are not acknowledged in the "Fact Sheet". Firstly of verifying the food has only been irradiated once, and secondly verification of the level at which it was irradiated

Consumers have a right to know if any food or any ingredient of processed food they eat has been irradiated. Merely insisting on the labelling of bulk foods or of whole foods which have been irradiated would be a labelling regime so ineffective as to be almost contemptible

As the IOCU (International Organisation of Consumers Unions) noted, how is the consumer's right of choice "to be protected if there is no detection test so that standards and inspection boards can check on the consumer's behalf?"⁷. Rules and standards are irrelevant if there is no means of verifying their violation

Doctor Lauria says "If the industry will not support a proper chromosome study and will not carry out proper nutritional studies (and provide the results on the food label), and if they do not agree to a prominent label now and in future years, permission for irradiating or importing irradiated foods (except for spices) should not be allowed"

Food Irradiation Campaign—Fact Sheet

Background