Although the World Health Organization also has approved the irradiation of food, it continues to have a bad rap among some food safety advocates, who say it will affect quality and taste. Irradiation is not permitted on organic foods in the United States. (Here's a more in-depth look at the food irradiation controversy.)
But even radiation is no magic bullet. "When salmonella gets in a dry environment, it is significantly more resistant to heat," says Brad Marks, a professor in Michigan State's Department of Biosystems and Agricultural Engineering, who is about to test X-rays as a method to decontaminate almonds and walnuts. "There's a salmonella that has gotten on almonds and caused two outbreaks."