After the September 11 Twin Towers destruction, several US Government officials and media outlets were sent anthrax-tainted mail. Five people died and about twelve others were treated for deadly inhalation anthrax or the milder skin anthrax. To kill any anthrax spores the US Post Office now routinely irradiates all mail to US lawmakers, but this appears to have had a further adverse effect on some postal workers who handle the mail. These included skin irritation, respiratory problems and nausea.

Whilst denying that irradiating mail leaves any residual radiation, a US Government report accepted that it resulted in the creation of previously unknown chemical compounds which can change the look, feel and smell of mailed documents. Mail yellows and becomes brittle. Enclosed plastic items are discoloured. Seeds, plants and other biological matter are sterilised. Gem stones are altered. Photographic film is ruined and computer disks and CDs are sometimes damaged.

Ed.- If that's what irradiation does to relatively inert matter like paper and plastic, imagine what it's doing to foods and spices.