234 USDA's operational experience in the growing use of irradiation as a plant quarantine treatment for safe trade
Alan Green, PhD: Executive Director of USDA-APHIS, PPQ Plant Health Programs, Washington, USA
E-Mail: Alan.S.Green@aphis.usda.gov
Abstract
Since 2002, the United States Department of Agriculture has accepted irradiation as a phytosanitary treatment for imported fruits and vegetables. The regulation is based on a proven treatment system including accurate dosimetry that delivers the minimum regulatory dosage to address specified regulated pests; and adequate safeguards to protect the product against potential re-infestation prior to entry into the United States. Successful irradiation programs initiated in Thailand and India for tropical fruits received outstanding consumer support. New programs are ready for startup in Vietnam and Mexico.
Irradiation as a phytosanitary treatment presents many new issues to manage. For example, the 400 Gray generic dose eliminates insects as a biological risk without necessarily killing them, and since verification of treatments relies primarily on documentation, the USDA now requires oversight arrangements in the country of origin. To further complicate the oversight initiatives, statute mandates that APHIS recoup these costs from the exporting country, adding costs to the treatment process. Other problems have included determining the necessary conditions such as ripeness, temperature and humidity controls to maximize the quality and shelf life of the fruit; and maintaining good agricultural practices and transportation conditions prior to packing to maximize fruit quality. Logistical problems have involved the locations of program orchards; use of multiple packages that require individual dose mappings; and the lack of a single commercial entity that represents each country's export program.
Future changes currently under considered include ways to reduce oversight expenses; centralizing the fruit inspections for all treatment facilities; supplementing dose mapping with expertise from local nuclear officials and agencies in the exporting country; exploring greater use of maritime transportation to the United States; and supporting research in developing generic doses for other broad categories of pests.
In spite of the complexities with the program to date and after two years of operations, the technology has been quite successful both in terms of customer acceptance and quarantine efficacy.