Food and agriculture applications

Tracers in agriculture

Tracers similar to those used in medicine are also used in agriculture for studying plants and for optimising the quantities of fertilizers and herbicides, both from economical considerations and for limiting the adverse effect of these substances to the environment (rivers, ground waters etc.). For this purpose, in order to assess the consumption of fertilizers and herbicides, Nitrogen – 15 and Phosphorus – 32 radioisotopes are used, by measuring the quantity of substance assimilated by the plant, compared with the total quantity initially administered.

Ionising radiations emitted by radioisotopes are also used for obtaining more productive crops and for obtaining crops more resistant to drought and disease, as well as crops with increased yield or crops with a shorter growing period. This technique is used for several decades, and it contributed to ensuring the food for some third world countries.

Insect control

In the entire world, the insects destroy approximately 10% of the agricultural crops. To control this threat, in the mating periods, insects artificially sterilized in the laboratory with the help of the ionising radiations are released in the environment. The female insects that mate with sterile male insects cannot reproduce anymore. Consequently, the population of insects can be rapidly decreased, the method of releasing the sterile insects in the nature being known as “sterile insect technique”(SIT).

SIT Technique is frequently used in some counties, with support from Food and Agriculture Organization of the United Nations (FAO) and from International Atomic Energy Agency (IAEA).

Food treatment and preservation

Ionising radiations also represent an alternative at the chemicals used in food treatment and preservation. Radiations can be used to extend the validity period for the food supplies.

Irradiation destroys bacteria that cause spoilage, as well as disease, such as salmonella poisoning, from meat and from other animal food. This thing allows a safe food supply, which can be stored for a long time.

Irradiation also inhibits the formation of tubers at fruits and vegetables, to delay their ripening. The result is that fresh fruits and vegetables can be stored longer before maturation.

Irradiation technique is particularly important when foods are exported in countries with tropical whether, where food can easily alter because of the high temperatures.

Food irradiation is achieved by means of accelerated electrons (beta radiations), and by ionising radiations emitted by the sources, such as Cobalt – 60 and Cesium -137 radioisotopes. X Rays are also used. None of these used radiation sources has enough energy to determine a remanent radioactivity in the treated food.

Quarantine and food export

Ionising radiations are used to destroy the parasites and the insects that can exist in the goods exported from a country. Radiation kills the parasites that can cause a major risk of quarantine in the destination countries.

In Australia, the technique is used for the decontamination of the materials such as fleece and wood for export. At international level, the method is frequently used for the transportation of the documents and of the historical archives.