Preventing Insects From Hitch-hiking to New Pastures

The first commercial food irradiation, back in the 1950s, was limited to dried herbs and spices. Few foods were treated. This continued until the 1980s when the process was officially recognized as safe by the Joint Division and the World Health Organization (WHO). Once declared safe, proponents expected it to be adopted immediately by commercial interests, but that did not happen. People misunderstood the term ‘irradiation’, equating it with radioactivity, even though, in reality, food irradiation uses photons, electrons or x-rays, in a process similar to security screening methods used at airports, but using higher intensity beams. The food never comes into contact with radioactive material; the beams do the work without significantly changing the food’s temperature or affecting its nutritional value. Irradiation maintains the quality and increases the safety of the food. Other methods used to control pests, such as cold treatments, vapor heat or chemical fumigants, can change the texture or taste of the food, or leave chemical residues. That does not happen with low intensity irradiation.

The prescription for the appropriate irradiation dose – how strong, how long – must be exact. This means determining which doses work best for which foods and which insects. For example, the International Plant Protection Convention has a series of 14 irradiation standards, backed by scientific evidence gathered by the Joint Division, that prescribe the safe use of irradiation for addressing specific insect pests.

Building from this base, the Joint Division began in 2010 to work on developing a generic one-fits-all irradiation application that could apply to a host of different insects, particularly those that are of quarantine importance. It also worked with 17 countries in Asia to develop guidelines for good irradiation practices which are now publicly available for use.

In addition to establishing dose levels and strategies for irradiating fruits and vegetables against regulated pests, the Joint Division supports exporting countries in setting up their own irradiation facilities. For example, Viet Nam was previously unable to export dragonfruit to lucrative western markets due to insect pests, but now the country is equipped to use radiation treatment to eliminate the pests without affecting the fruit’s safety or nutritional quality.

The Division also links exporters in poor countries that have no facilities to irradiation operations in importing countries, making it possible for them to irradiate their shipments on arrival. This means that though, for example, Pakistani mango growers do not have access to an irradiation facility in their country, they are still able to export their globally-appreciated mangoes to countries like the United States, where the importing country irradiates the mangoes upon arrival.