NON ENERGY APPLICATIONS OF NUCLEAR SCIENCE
Source: BUILDING A BETTER FUTURE:
CONTRIBUTIONS OF NUCLEAR SCIENCE AND TECHNOLOGY, the International Atomic
Energy Agency’s (IAEA’s) Department of Research and Isotopes
and Division of Public Information, and Kathryn Ronald (consultant).
MEETING THE CHALLENGE OF FOOD FOR ALL
More than 800 million people, mainly in Africa and
Asia, suffer from hunger. Most depend on agriculture for their livelihood;
many rely on imported food or relief aid for their very existence.
Developing new Strains of Plants
Many factors affecting plant growth and crop quality,
such as drought, insects and disease, are often beyond farmers’
control. While it is difficult to create ideal growing conditions, for
the last three decades it has become possible to produce plants that
are better “tailored” to thrive in imperfect conditions
by drawing on the skills of the plant geneticist and maximising opportunities
afforded by radiation technology.
Plant scientists can induce subtle changes or mutations
in the genetic make up (DNA) in plant seeds, buds or tissue. By monitoring
plant growth, they can identify and select strains with the desired
characteristics and develop cultivars for direct use or further cross-breeding.
This is the case of science imitating nature. Mutations occur naturally,
though extremely rarely, due to factors such as mistakes in DNA replication.
Thanks to the controlled use of ionising radiation,
this natural diversity can be increased as much as 10,000-fold and the
development of new varieties significantly accelerated.
Boosting Soil Productivity
Soil nutrients and water are essential to plant growth,
but in many areas of the developing world soils are deficient in key
nutrients. Sustainable agriculture depends on maintaining a balance
between consuming and conserving soil nutrients and water resources.
Stable and radioactive isotopes can play a crucial
role in understanding soil-plant interactions and in helping to increase
crop production through better soil management.
MORE RATIONAL USE OF MINERAL FERTILISERS
Isotope studies of lowland rice in
Bangladesh, Egypt, Pakistan and Thailand demonstrated that nitrogen
and phosphorus fertilisers are used far more effectively when placed
below the soil surface. Trials in Argentina, Brazil, Colombia, Egypt,
Peru and Romania revealed a 20 percent increase in fertiliser uptake
when mixed nitrogen and phosphorus fertilisers are applied at the optimum
time in the growing season.
Based on this and other work, many developing countries
have achieved more economical use of fertilisers while avoiding environmental
pollution. Today’s research and development work focuses on using
organic materials to reduce the need for mineral fertilisers. Nuclear
methods are helping to assess crop residues and locally available
wastes, including radiation-sterilised sewage sludge,
as ecologically sound nutrient sources.
IMPROVED WATER USE
Efficient use of water by crops and pastures is important
in the quest for food security. The International Atomic Energy Agency
(IAEA) and the Food and Agriculture Organisation (FAO) are promoting
better practices and modern irrigation technologies using sprinklers,
mini-sprayers and drippers. Application of the new methods is enhanced
with the use of neutron moisture gauges,
nuclear-based instruments that accurately measure soil moisture content.
Increasing Output of Meat and Milk
BETTER FEEDS FROM LOCAL RESOURCES
Isotopes provide unique information
about the nutrition of farm animals – data that can be used to
find better ways of converting animal feeds into milk and meat. In countries
where isotope-based concepts have been widely adopted, research has
paid handsome dividends in terms of higher animal productivity and improved
nutrition and health of consumers.
IMPROVING BREEDING EFFICIENCY
Better feeding works best with improved animal breeding
strategies. The use of radioimmunoassay (RIA) to measure hormones, and thus monitor more closely reproductive processes,
has been essential to advancing breeding practices in industrialised
countries. RIA makes it possible to determine when animals are ready
for breeding, to diagnose pregnancy earlier; to correct health disorders
and to improve artificial insemination. These advances have been transferred
to many developing countries so that they too can improve their livestock.
Controlling Insect Pests
Inserts reduce food production through both direct
damage and the diseases they spread to crops and livestock. Pest control
using chemical insecticides is routine and widespread. But pesticides
can pollute the environment, contaminate food and water; destroy beneficial
insects and even increase resistance in target species.
Nuclear-based techniques can reduce
and, in some cases, eradicate insect pests that are harmful.
SIT: INSECT BIRTH CONTROL
The Sterile Insect Technique (SIT) is an environmentally
sound pest-control method. It involves mass rearing of insects and sterilising
the males with gamma radiation, followed by their release
in target areas. Although the sterile male insects find and mate with
wild females, no offspring are produced. With continuing releases, SIT
can effectively eradicate insects in a defined area.
SIT has been successfully applied in combating the
Mediterranean fruit fly, or medfly, which attacks over 250 species of
fruit and vegetables. So great is the potential damage of medfly that
countries free of it prohibit imports of fresh produce from countries
where the pest is endemic.
Improving Food Quality and Safety
About one-quarter of all food produced is lost to insects,
bacteria and rodents. Add to this the recurrent illnesses due to food
contamination, and it is not surprising that effective food preservation
is increasingly critical to food safety and security.
IRRADIATION AND FOOD STANDARDS: PASSPORT TO INTERNAL TRADE
Food irradiation allows the complete
disinfestations of grain, spices, vegetable seasonings and dried fruit
destined for long-term storage. It also inhibits sprouting, and extends
the shelf-life of fresh produce that can spoil in transit. In poultry
and red meat, irradiation destroys bacteria associated with food-borne
diseases. The carefully controlled radiation comes from either a Cobalt-60
source or from an electron beam accelerator: It is a clean,
fast, efficient and energy-saving technology.
Irradiated food does not become radioactive and it
does not create residues. By contrast, some chemical treatments not
only leave behind toxins, but are harmful to the environment. Methyl
bromide, for example, is one of the ozone-depleting substances being
phased out under the Montreal Protocol. Increasingly, both Governments
and the private sector are interested in expanding the use of food irradiation.
Together with the World Health Organisation (WHO),
the IAEA and FAO have sponsored extensive research into the safety of
irradiated foods. Studies prove that radiation does not reduce the wholesomeness
or sensory qualities of food, and there is increasing global recognition
that radiation technology can help safeguard public health and reduce