Dry Sterilization Procedures Based on Variable Frequency Microwave Technology

Several of the present methods of decontamination of biothreat agents, especially the spore-forming Bacillus anthracis (anthrax) rely on steam or disinfection with highly corrosive agents. While these methods are effective, such procedures are impractical when the contaminated materials and/or equipment are mail, paper documents, delicate instruments, or complex machinery such as mail sorting equipment. The development of a non-corrosive and non-damaging process to decontaminate these types of materials and equipment presents a major challenge. A body of literature suggests that microwave energy can be used to neutralize bacterial spores, with thermal effects as the presumed killing mechanism. Other sources have suggested that there exists a "microwave effect" that contributes a second killing mechanism to the bacteria neutralizing process. The purpose of the proposed research is to evaluate the application of variable frequency microwave output to the neutralization of dry Anthrax spores, to isolate potential "microwave" effects from the thermal effects of conventional dry heat sterilization, and to characterize these potential effects. The research will use simulated contaminated mail as decontamination targets.