An interesting question and one that long needs answering.
Thus far I have found a dearth of negative research on the topic. In 2005 the American Meat Institute Petitioned FSIS “To Recognize the Use of E-Beam on Carcasses as a Processing Aid” and attached studies seem clearly to indicate that this is an effective technology in reducing the risks of bacterial contamination from carcasses. In late 2008, a Presentation on the topic was given both in written form and by the below PowerPoint (click on immage). A transcript of the Presentation is also available.
The real questions are:
1. Is the technology effective in killing bacteria?
2. Is the technology safe to humans and the environment? And,
3. Should the meat so produced be labeled with some type of irradiation designation?
I think the answers are yes, yes and yes.
Input from readers?