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THE BRITISH government said last week that it would soon allow irradiated
food to go on sale in Britain. The announcement, by the Minister of Agriculture,
John MacGregor, provoked predictably strong reactions. David Clark, the
Opposition spokesman on agriculture, said that the minister was introducing
the process to cover up sloppy standards in the food industry.

Food irradiation kills most of the bacteria that occur naturally on
food. Some of these organisms produce toxins that cause salmonella poisoning
and, occasionally, botulism. The process also slows down the natural development
and ripening of plant material by affecting the normal process of cell division
or by inhibiting the control of growth hormones.

Recent public scandals have involved the spread of salmonella infection
and a lethal outbreak of botulism poisoning. ‘Food irradiation is like covering
up rotten wood with gloss paint,’ said Clark. Tim Lang of the London Food
Commission, an independent body with a reputation for strident opposition
to the food industry, said that the government was ‘legalising fraud’.

There is strong resistance among consumers in Britain, and other countries,
to food irradiation. A survey by the Consumers’ Association last year found
that 84 per cent of people in Britain were opposed to the practice.

Yet most research shows that food irradiation is safe and has no serious
harmful effects on the taste or wholesomeness of many foods, provided that
levels of irradiation are kept below prescribed limits.

A food irradiation plant incorporates a radiation source, usually cobalt-60
or caesium-137, which produces gamma-rays, and a conveyor belt which passes
food under the source. The strength of the source, the speed of the conveyor
and the shape of the packages determine how much radiation the food receives.
A thick concrete wall surrounds the plant to contain the radiation.

In Britain such plants have been used for more than 20 years to sterilise
medical equipment. But as it costs between Pounds sterling 2 million and
Pounds sterling 3 million to build one of the plants, few are likely to
be built in the immediate future specifically for irradiating food.

Food irradiation was first used in 1921 to kill the human parasite called
Trichinella spiralis, found in pigs. In 1930, a French patent was granted
for the preservation of food by irradiation. However, the process did not
catch on until 1945 with the production of cheap radioisotopes.

Most research on food irradiation in Britain was carried out between
1948 and 1965 at the Agricultural and Food Research Council’s low-temperature
research station at Cambridge and its Torry research station at Aberdeen,
as well as the UK Atomic Energy Authority’s laboratory in Wantage, Oxfordshire.
Researchers at the laboratories calculated most of the practical parameters.
They discovered, for example, the doses required to kill particular species
of bacteria in food without affecting its flavour.

Radiation splits the molecules in food into highly reactive radicals
which combine with other molecules to form radiolytic products. As yet,
no one has devised a test for radiolytic products so it is impossible to
tell whether food has been irradiated.

Irradiation affects different foods in different ways. It breaks long
molecules, such as cellulose, into shorter carbohydrates. As cellulose is
the main constituent of the walls of plant cells, some fruits and vegetables
become soft and lose their characteristic texture after irradiation.

The irradiation of fats creates free radicals that oxidise the fats
and can turn food rancid. Radiation can break down proteins, but the low
levels recommended for use on food should ensure that this does not happen.
Radiation does, however, destroy a proportion of some vitamins, though estimates
vary wildly, ranging from 4 to 40 per cent.

Despite assurances from British scientists that food irradiation was
safe, the British government banned the production and import of irradiated
food in 1964 apart from special cases where food is sterilised for intensive-care
patients whose immune system has been suppressed. Other countries permitted
its use, though none have taken it up to any great extent. Today, 35 countries,
including France and the US, irradiate some of their food.

In 1970, a Joint Expert Committee on Food Irradiation, set up by UN
agencies, pronounced food irradiation safe. The same committee confirmed
in 1980 that the irradiation of food up to an average overall dose of 10
kilograys of radiation was safe and introduced no special nutritional or
microbiological problems.

These reports prompted the British government to set up a scientific
committee of scientists chaired by Sir Arnold Burgen of the University of
Cambridge to investigate food irradiation. The committee, known as the Advisory
Committee on Irradiated and Novel Foods, concluded that ‘correctly applied’,
food irradiation ‘provides an effective and efficient food preservation
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The committee was satisfied that there would be no change in the low
levels of radioactivity that food naturally contains.

This view was further confirmed by a report from the WHO, published
in December 1988. The WHO said that: ‘Food irradiation is a technology that
can, under certain circumstances, be safely used to help control two of
the most serious problems concerned with food supplies: the huge avoidable
losses of food through deterioration and the illness and deaths that result
from the consumption of contaminated food.’

Objectors to the process argue that even if the process is safe it deals
with the symptoms of wider problems. According to Clark, ‘food irradiation
will mask poor standards of hygiene and handling within the food industry’.

MacGregor has promised that processing plants that carry out irradiation
will be strictly policed to ensure that food is fit for human consumption
before it is irradiated. Geoffrey Campbell-Platt, professor of food technology
at the University of Reading, says that, in any case, irradiation cannot
be used to mask food that is unfit to eat. ‘If food is spoiled before it
is irradiated it will still appear spoiled. Food irradiation can’t make
bad food good,’ he says.

Another fear is that irradiation might make microbes mutate into a more
dangerous form. However, this is unlikely unless an irradiated population
of bacteria is allowed to grow and is irradiated again to encourage such
mutants. Campbell-Platt says ‘food itself is radioactive, as are all complex
biological systems. Irradiating it with low levels of radiation does not
significantly increase levels of radioactivity.’

Irradiation does lead to a decline in the level of vitamins A, B, C
and E in food, and to the creation of reactive chemical species known as
free radicals. Campbell-Platt argues, however, that other methods of processing
food, including cooking, reduce its nutritional value by a similar amount.

‘The amount of nutritional loss by irradiating food is similar to that
which fresh peas lose after they have been kept for several days and cooked.
The free radicals that arise during irradiation also arise when non-irradiated
food is cooked. People have picked up on these things as if they are new.
They are not new. All methods of food processing, including freezing and
pasteurisation, affect food in all these ways.’

Irradiation slows down the rate at which food decays, an advantage that
consumers might eventually find appealing. This longer shelf life also enables
farmers to keep more of their produce for longer.

Much of the trade literature promotes irradiation as a more effective
alternative to chemical treatment for such tasks as preventing potatoes
and onions from sprouting while in store and for controlling insect infestation
in harvested crops. Irradiation is likely to prove more expensive than treating
food chemically, particularly on a small scale.

If irradiation is effective the gains could be great. More than a quarter
of harvested food is lost due to various kinds of spoilage and wastage.
Ironically, irradiation could hold out the prospects of reducing the contact
of many foods with chemicals that are designed to prevent the growth of
infestations. Many food scientists see much more reason for consumers to
fear these chemicals than irradiation.

In an article in the International Atomic Energy Bulletin, J. van Kooij
of the International Atomic Energy Agency argued that food irradiation could
provide an environmentally sound way of preserving crops. ‘Curing, chemical
preservation and fumigation are all being questioned with regard to their
biological safety,’ he says. ‘Irradiation can replace, or drastically reduce,
the use of food additives and fumigants which pose hazards for the consumers
as well as workers in food processing factories.’

He suggests that developing countries in particular could reduce their
losses of harvested crops. One of the limiting factors in the widespread
use of food irradiation in developing countries is that scientists in these
countries have limited know-how.

The task now, argues van Kooij, is to allay consumers’ fears on food
irradiation. ‘In order to promote worldwide introduction of food irradiation
it is necessary to develop national legislation and regulatory procedures
that will enhance confidence among trading nations that foods irradiated
in one country and offered for sale in another, have been subject to commonly
acceptable standards of wholesomeness and hygienic practice,’ he says.

Clark sees the government’s decision as a victory for big business,
which has been lobbying Whitehall for many years for the introduction of
food irradiation. Now, he says, they have been able to offer ministers a
‘technological fix’ to assuage public fears about the safety of British
food. As the government cuts spending on R&D for food and closes research
centres, Clark told the House of Commons last week, they are offering irradiation
as ‘a new panacea’ to fill the gap.

MacGregor insists that irradiation is being introduced ‘because of considerations
of consumer safety. Irradiation has a useful contribution to make – a contribution,
not the total solution – to the reduction of food-borne diseases in certain
products.’ He promises that all irradiated food would be clearly labelled.
‘It will not be thrust down anyone’s throat,’ he promised.

What happens if something goes wrong with the process in a particular
factory and poor quality food is irradiated too much? According to Bevan
Moseley of the Institute of Food Research in Reading, food that has been
irradiated too much will taste and smell off, so people will not eat it.
Nevertheless, MacGregor has promised a rigorous system to license plants
that carry out irradiation and to monitor quality.

All food will be inspected before it is irradiated and numbered before
it leaves so that it can be traced. Policing will be relatively straightforward,
at least at the beginning, because high capital costs for irradiation plant
and consumer resistance will slow the pace of the introduction of irradiation.

Of all food processing techniques, food irradiation has undergone the
most prolonged and intensive analyses. Independent committees of scientists
agree that the process, if applied correctly, is safe. The caveat, however,
is the point. The technology has been thoroughly tested but the method of
policing it has not.